Mailing List Archive

[PATCH v13 10/10] tty: serial: Add Nuvoton ma35d1 serial driver support
From: Jacky Huang <ychuang3@nuvoton.com>

This adds UART and console driver for Nuvoton ma35d1 Soc.
It supports full-duplex communication, FIFO control, and
hardware flow control.

Signed-off-by: Jacky Huang <ychuang3@nuvoton.com>
---
drivers/tty/serial/Kconfig | 18 +
drivers/tty/serial/Makefile | 1 +
drivers/tty/serial/ma35d1_serial.c | 808 +++++++++++++++++++++++++++++
include/uapi/linux/serial_core.h | 3 +
4 files changed, 830 insertions(+)
create mode 100644 drivers/tty/serial/ma35d1_serial.c

diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 3e3fb377d90d..71ea5138adce 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1555,6 +1555,24 @@ config SERIAL_SUNPLUS_CONSOLE
you can alter that using a kernel command line option such as
"console=ttySUPx".

+config SERIAL_NUVOTON_MA35D1
+ tristate "Nuvoton MA35D1 family UART support"
+ depends on ARCH_MA35 || COMPILE_TEST
+ select SERIAL_CORE
+ help
+ This driver supports Nuvoton MA35D1 family UART ports. If you would
+ like to use them, you must answer Y or M to this option. Note that
+ for use as console, it must be included in kernel and not as a
+ module
+
+config SERIAL_NUVOTON_MA35D1_CONSOLE
+ bool "Console on a Nuvotn MA35D1 family UART port"
+ depends on SERIAL_NUVOTON_MA35D1=y
+ select SERIAL_CORE_CONSOLE
+ help
+ Select this options if you'd like to use the UART port0 of the
+ Nuvoton MA35D1 family as a console.
+
endmenu

config SERIAL_MCTRL_GPIO
diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
index cd9afd9e3018..0e823851c42c 100644
--- a/drivers/tty/serial/Makefile
+++ b/drivers/tty/serial/Makefile
@@ -93,3 +93,4 @@ obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o

obj-$(CONFIG_SERIAL_KGDB_NMI) += kgdb_nmi.o
obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o
+obj-$(CONFIG_SERIAL_NUVOTON_MA35D1) += ma35d1_serial.o
diff --git a/drivers/tty/serial/ma35d1_serial.c b/drivers/tty/serial/ma35d1_serial.c
new file mode 100644
index 000000000000..6c19da7731a6
--- /dev/null
+++ b/drivers/tty/serial/ma35d1_serial.c
@@ -0,0 +1,808 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * MA35D1 serial driver
+ * Copyright (C) 2023 Nuvoton Technology Corp.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/serial_core.h>
+#include <linux/slab.h>
+#include <linux/tty_flip.h>
+#include <linux/units.h>
+
+#define MA35_UART_NR 17
+
+#define MA35_RBR_REG 0x00
+#define MA35_THR_REG 0x00
+#define MA35_IER_REG 0x04
+#define MA35_FCR_REG 0x08
+#define MA35_LCR_REG 0x0C
+#define MA35_MCR_REG 0x10
+#define MA35_MSR_REG 0x14
+#define MA35_FSR_REG 0x18
+#define MA35_ISR_REG 0x1C
+#define MA35_TOR_REG 0x20
+#define MA35_BAUD_REG 0x24
+#define MA35_ALTCTL_REG 0x2C
+#define MA35_FUN_SEL_REG 0x30
+#define MA35_WKCTL_REG 0x40
+#define MA35_WKSTS_REG 0x44
+
+/* MA35_IER_REG - Interrupt Enable Register */
+#define MA35_IER_RDA_IEN BIT(0) /* RBR Available Interrupt Enable */
+#define MA35_IER_THRE_IEN BIT(1) /* THR Empty Interrupt Enable */
+#define MA35_IER_RLS_IEN BIT(2) /* RX Line Status Interrupt Enable */
+#define MA35_IER_RTO_IEN BIT(4) /* RX Time-out Interrupt Enable */
+#define MA35_IER_BUFERR_IEN BIT(5) /* Buffer Error Interrupt Enable */
+#define MA35_IER_TIME_OUT_EN BIT(11) /* RX Buffer Time-out Counter Enable */
+#define MA35_IER_AUTO_RTS BIT(12) /* nRTS Auto-flow Control Enable */
+#define MA35_IER_AUTO_CTS BIT(13) /* nCTS Auto-flow Control Enable */
+
+/* MA35_FCR_REG - FIFO Control Register */
+#define MA35_FCR_RFR BIT(1) /* RX Field Software Reset */
+#define MA35_FCR_TFR BIT(2) /* TX Field Software Reset */
+#define MA35_FCR_RFITL_MASK GENMASK(7, 4) /* RX FIFO Interrupt Trigger Level */
+#define MA35_FCR_RFITL_1BYTE FIELD_PREP(MA35_FCR_RFITL_MASK, 0)
+#define MA35_FCR_RFITL_4BYTES FIELD_PREP(MA35_FCR_RFITL_MASK, 1)
+#define MA35_FCR_RFITL_8BYTES FIELD_PREP(MA35_FCR_RFITL_MASK, 2)
+#define MA35_FCR_RFITL_14BYTES FIELD_PREP(MA35_FCR_RFITL_MASK, 3)
+#define MA35_FCR_RFITL_30BYTES FIELD_PREP(MA35_FCR_RFITL_MASK, 4)
+#define MA35_FCR_RTSTL_MASK GENMASK(19, 16) /* nRTS Trigger Level */
+#define MA35_FCR_RTSTL_1BYTE FIELD_PREP(MA35_FCR_RTSTL_MASK, 0)
+#define MA35_FCR_RTSTL_4BYTES FIELD_PREP(MA35_FCR_RTSTL_MASK, 1)
+#define MA35_FCR_RTSTL_8BYTES FIELD_PREP(MA35_FCR_RTSTL_MASK, 2)
+#define MA35_FCR_RTSTL_14BYTES FIELD_PREP(MA35_FCR_RTSTL_MASK, 3)
+#define MA35_FCR_RTSTLL_30BYTES FIELD_PREP(MA35_FCR_RTSTL_MASK, 4)
+
+/* MA35_LCR_REG - Line Control Register */
+#define MA35_LCR_NSB BIT(2) /* Number of “STOP Bit” */
+#define MA35_LCR_PBE BIT(3) /* Parity Bit Enable */
+#define MA35_LCR_EPE BIT(4) /* Even Parity Enable */
+#define MA35_LCR_SPE BIT(5) /* Stick Parity Enable */
+#define MA35_LCR_BREAK BIT(6) /* Break Control */
+#define MA35_LCR_WLS_MASK GENMASK(1, 0) /* Word Length Selection */
+#define MA35_LCR_WLS_5BITS FIELD_PREP(MA35_LCR_WLS_MASK, 0)
+#define MA35_LCR_WLS_6BITS FIELD_PREP(MA35_LCR_WLS_MASK, 1)
+#define MA35_LCR_WLS_7BITS FIELD_PREP(MA35_LCR_WLS_MASK, 2)
+#define MA35_LCR_WLS_8BITS FIELD_PREP(MA35_LCR_WLS_MASK, 3)
+
+/* MA35_MCR_REG - Modem Control Register */
+#define MA35_MCR_RTS_CTRL BIT(1) /* nRTS Signal Control */
+#define MA35_MCR_RTSACTLV BIT(9) /* nRTS Pin Active Level */
+#define MA35_MCR_RTSSTS BIT(13) /* nRTS Pin Status (Read Only) */
+
+/* MA35_MSR_REG - Modem Status Register */
+#define MA35_MSR_CTSDETF BIT(0) /* Detect nCTS State Change Flag */
+#define MA35_MSR_CTSSTS BIT(4) /* nCTS Pin Status (Read Only) */
+#define MA35_MSR_CTSACTLV BIT(8) /* nCTS Pin Active Level */
+
+/* MA35_FSR_REG - FIFO Status Register */
+#define MA35_FSR_RX_OVER_IF BIT(0) /* RX Overflow Error Interrupt Flag */
+#define MA35_FSR_PEF BIT(4) /* Parity Error Flag*/
+#define MA35_FSR_FEF BIT(5) /* Framing Error Flag */
+#define MA35_FSR_BIF BIT(6) /* Break Interrupt Flag */
+#define MA35_FSR_RX_EMPTY BIT(14) /* Receiver FIFO Empty (Read Only) */
+#define MA35_FSR_RX_FULL BIT(15) /* Receiver FIFO Full (Read Only) */
+#define MA35_FSR_TX_EMPTY BIT(22) /* Transmitter FIFO Empty (Read Only) */
+#define MA35_FSR_TX_FULL BIT(23) /* Transmitter FIFO Full (Read Only) */
+#define MA35_FSR_TX_OVER_IF BIT(24) /* TX Overflow Error Interrupt Flag */
+#define MA35_FSR_TE_FLAG BIT(28) /* Transmitter Empty Flag (Read Only) */
+#define MA35_FSR_RXPTR_MSK GENMASK(13, 8) /* TX FIFO Pointer mask */
+#define MA35_FSR_TXPTR_MSK GENMASK(21, 16) /* RX FIFO Pointer mask */
+
+/* MA35_ISR_REG - Interrupt Status Register */
+#define MA35_ISR_RDA_IF BIT(0) /* RBR Available Interrupt Flag */
+#define MA35_ISR_THRE_IF BIT(1) /* THR Empty Interrupt Flag */
+#define MA35_ISR_RLSIF BIT(2) /* Receive Line Interrupt Flag */
+#define MA35_ISR_MODEMIF BIT(3) /* MODEM Interrupt Flag */
+#define MA35_ISR_RXTO_IF BIT(4) /* RX Time-out Interrupt Flag */
+#define MA35_ISR_BUFEIF BIT(5) /* Buffer Error Interrupt Flag */
+#define MA35_ISR_WK_IF BIT(6) /* UART Wake-up Interrupt Flag */
+#define MA35_ISR_RDAINT BIT(8) /* RBR Available Interrupt Indicator */
+#define MA35_ISR_THRE_INT BIT(9) /* THR Empty Interrupt Indicator */
+#define MA35_ISR_ALL 0xFFFFFFFF
+
+/* MA35_BAUD_REG - Baud Rate Divider Register */
+#define MA35_BAUD_MODE_MASK GENMASK(29, 28)
+#define MA35_BAUD_MODE0 FIELD_PREP(MA35_BAUD_MODE_MASK, 0)
+#define MA35_BAUD_MODE1 FIELD_PREP(MA35_BAUD_MODE_MASK, 2)
+#define MA35_BAUD_MODE2 FIELD_PREP(MA35_BAUD_MODE_MASK, 3)
+#define MA35_BAUD_MASK GENMASK(15, 0)
+
+/* MA35_ALTCTL_REG - Alternate Control/Status Register */
+#define MA35_ALTCTL_RS485AUD BIT(10) /* RS-485 Auto Direction Function */
+
+/* MA35_FUN_SEL_REG - Function Select Register */
+#define MA35_FUN_SEL_MASK GENMASK(2, 0)
+#define MA35_FUN_SEL_UART FIELD_PREP(MA35_FUN_SEL_MASK, 0)
+#define MA35_FUN_SEL_RS485 FIELD_PREP(MA35_FUN_SEL_MASK, 3)
+
+/* The constrain for MA35D1 UART baud rate divider */
+#define MA35_BAUD_DIV_MAX 0xFFFF
+#define MA35_BAUD_DIV_MIN 11
+
+/* UART FIFO depth */
+#define MA35_UART_FIFO_DEPTH 32
+/* UART console clock */
+#define MA35_UART_CONSOLE_CLK (24 * HZ_PER_MHZ)
+/* UART register ioremap size */
+#define MA35_UART_REG_SIZE 0x100
+/* Rx Timeout */
+#define MA35_UART_RX_TOUT 0x40
+
+#define MA35_ISR_IF_CHECK (MA35_ISR_RDA_IF | MA35_ISR_RXTO_IF | \
+ MA35_ISR_THRE_INT | MA35_ISR_BUFEIF)
+
+static struct uart_driver ma35d1serial_reg;
+
+struct uart_ma35d1_port {
+ struct uart_port port;
+ struct clk *clk;
+ u16 capabilities; /* port capabilities */
+ u8 ier;
+ u8 lcr;
+ u8 mcr;
+ u32 baud_rate;
+ u32 console_baud_rate;
+ u32 console_line;
+ u32 console_int;
+};
+
+static struct uart_ma35d1_port ma35d1serial_ports[MA35_UART_NR];
+
+static struct uart_ma35d1_port *to_ma35d1_uart_port(struct uart_port *uart)
+{
+ return container_of(uart, struct uart_ma35d1_port, port);
+}
+
+static u32 serial_in(struct uart_ma35d1_port *p, u32 offset)
+{
+ return readl_relaxed(p->port.membase + offset);
+}
+
+static void serial_out(struct uart_ma35d1_port *p, u32 offset, u32 value)
+{
+ writel_relaxed(value, p->port.membase + offset);
+}
+
+static void __stop_tx(struct uart_ma35d1_port *p)
+{
+ u32 ier;
+
+ ier = serial_in(p, MA35_IER_REG);
+ if (ier & MA35_IER_THRE_IEN)
+ serial_out(p, MA35_IER_REG, ier & ~MA35_IER_THRE_IEN);
+}
+
+static void ma35d1serial_stop_tx(struct uart_port *port)
+{
+ struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+ __stop_tx(up);
+}
+
+static void transmit_chars(struct uart_ma35d1_port *up)
+{
+ u32 count;
+ u8 ch;
+
+ if (uart_tx_stopped(&up->port)) {
+ ma35d1serial_stop_tx(&up->port);
+ return;
+ }
+ count = MA35_UART_FIFO_DEPTH - FIELD_GET(MA35_FSR_TXPTR_MSK,
+ serial_in(up, MA35_FSR_REG));
+ uart_port_tx_limited(&up->port, ch, count,
+ !(serial_in(up, MA35_FSR_REG) & MA35_FSR_TX_FULL),
+ serial_out(up, MA35_THR_REG, ch),
+ ({}));
+}
+
+static void ma35d1serial_start_tx(struct uart_port *port)
+{
+ struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+ u32 ier;
+
+ ier = serial_in(up, MA35_IER_REG);
+ serial_out(up, MA35_IER_REG, ier & ~MA35_IER_THRE_IEN);
+ transmit_chars(up);
+ serial_out(up, MA35_IER_REG, ier | MA35_IER_THRE_IEN);
+}
+
+static void ma35d1serial_stop_rx(struct uart_port *port)
+{
+ struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+ serial_out(up, MA35_IER_REG, serial_in(up, MA35_IER_REG) & ~MA35_IER_RDA_IEN);
+}
+
+static void receive_chars(struct uart_ma35d1_port *up)
+{
+ u8 ch, flag;
+ u32 fsr;
+ int max_count = 256;
+
+ fsr = serial_in(up, MA35_FSR_REG);
+ do {
+ flag = TTY_NORMAL;
+ up->port.icount.rx++;
+
+ if (unlikely(fsr & (MA35_FSR_BIF | MA35_FSR_FEF |
+ MA35_FSR_PEF | MA35_FSR_RX_OVER_IF))) {
+ if (fsr & MA35_FSR_BIF) {
+ up->port.icount.brk++;
+ if (uart_handle_break(&up->port))
+ continue;
+ }
+ if (fsr & MA35_FSR_FEF)
+ up->port.icount.frame++;
+ if (fsr & MA35_FSR_PEF)
+ up->port.icount.parity++;
+ if (fsr & MA35_FSR_RX_OVER_IF)
+ up->port.icount.overrun++;
+
+ serial_out(up, MA35_FSR_REG,
+ fsr & (MA35_FSR_BIF | MA35_FSR_FEF |
+ MA35_FSR_PEF | MA35_FSR_RX_OVER_IF));
+ if (fsr & MA35_FSR_BIF)
+ flag = TTY_BREAK;
+ else if (fsr & MA35_FSR_PEF)
+ flag = TTY_PARITY;
+ else if (fsr & MA35_FSR_FEF)
+ flag = TTY_FRAME;
+ }
+
+ ch = serial_in(up, MA35_RBR_REG);
+ if (uart_handle_sysrq_char(&up->port, ch))
+ continue;
+
+ spin_lock(&up->port.lock);
+ uart_insert_char(&up->port, fsr, MA35_FSR_RX_OVER_IF, ch, flag);
+ spin_unlock(&up->port.lock);
+
+ fsr = serial_in(up, MA35_FSR_REG);
+ } while (!(fsr & MA35_FSR_RX_EMPTY) && (max_count-- > 0));
+
+ spin_lock(&up->port.lock);
+ tty_flip_buffer_push(&up->port.state->port);
+ spin_unlock(&up->port.lock);
+}
+
+static irqreturn_t ma35d1serial_interrupt(int irq, void *dev_id)
+{
+ struct uart_port *port = dev_id;
+ struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+ u32 isr, fsr;
+
+ isr = serial_in(up, MA35_ISR_REG);
+ fsr = serial_in(up, MA35_FSR_REG);
+
+ if (!(isr & MA35_ISR_IF_CHECK))
+ return IRQ_NONE;
+
+ if (isr & (MA35_ISR_RDA_IF | MA35_ISR_RXTO_IF))
+ receive_chars(up);
+ if (isr & MA35_ISR_THRE_INT)
+ transmit_chars(up);
+ if (fsr & MA35_FSR_TX_OVER_IF)
+ serial_out(up, MA35_FSR_REG, MA35_FSR_TX_OVER_IF);
+
+ return IRQ_HANDLED;
+}
+
+static u32 ma35d1serial_tx_empty(struct uart_port *port)
+{
+ struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+ u32 fsr;
+
+ fsr = serial_in(up, MA35_FSR_REG);
+ return (fsr & (MA35_FSR_TE_FLAG | MA35_FSR_TX_EMPTY)) ==
+ (MA35_FSR_TE_FLAG | MA35_FSR_TX_EMPTY) ? TIOCSER_TEMT : 0;
+}
+
+static u32 ma35d1serial_get_mctrl(struct uart_port *port)
+{
+ struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+ u32 status;
+ u32 ret = 0;
+
+ status = serial_in(up, MA35_MSR_REG);
+ if (!(status & MA35_MSR_CTSSTS))
+ ret |= TIOCM_CTS;
+ return ret;
+}
+
+static void ma35d1serial_set_mctrl(struct uart_port *port, u32 mctrl)
+{
+ struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+ u32 mcr;
+ u32 ier;
+
+ mcr = serial_in(up, MA35_MCR_REG);
+ mcr &= ~MA35_MCR_RTS_CTRL;
+
+ if (mctrl & TIOCM_RTS)
+ mcr |= MA35_MCR_RTSACTLV;
+ else
+ mcr &= ~MA35_MCR_RTSACTLV;
+
+ if (up->mcr & UART_MCR_AFE) {
+ serial_out(up, MA35_IER_REG, (serial_in(up, MA35_IER_REG) |
+ MA35_IER_AUTO_RTS |
+ MA35_IER_AUTO_CTS));
+ up->port.flags |= UPF_HARD_FLOW;
+ } else {
+ ier = serial_in(up, MA35_IER_REG);
+ ier &= ~(MA35_IER_AUTO_RTS | MA35_IER_AUTO_CTS);
+ serial_out(up, MA35_IER_REG, ier);
+ up->port.flags &= ~UPF_HARD_FLOW;
+ }
+ serial_out(up, MA35_MSR_REG, (serial_in(up, MA35_MSR_REG) |
+ MA35_MSR_CTSACTLV));
+ serial_out(up, MA35_MCR_REG, mcr);
+}
+
+static void ma35d1serial_break_ctl(struct uart_port *port, int break_state)
+{
+ struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+ unsigned long flags;
+ u32 lcr;
+
+ spin_lock_irqsave(&up->port.lock, flags);
+ lcr = serial_in(up, MA35_LCR_REG);
+ if (break_state != 0)
+ lcr |= MA35_LCR_BREAK;
+ else
+ lcr &= ~MA35_LCR_BREAK;
+ serial_out(up, MA35_LCR_REG, lcr);
+ spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static int ma35d1serial_startup(struct uart_port *port)
+{
+ struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+ int retval;
+
+ /* Reset FIFO */
+ serial_out(up, MA35_FCR_REG, MA35_FCR_TFR | MA35_FCR_RFR);
+
+ /* Clear pending interrupts */
+ serial_out(up, MA35_ISR_REG, MA35_ISR_ALL);
+
+ retval = request_irq(port->irq, ma35d1serial_interrupt, 0,
+ dev_name(port->dev), port);
+ if (retval) {
+ dev_err(up->port.dev, "request irq failed.\n");
+ return retval;
+ }
+
+ serial_out(up, MA35_FCR_REG, serial_in(up, MA35_FCR_REG) |
+ MA35_FCR_RFITL_4BYTES | MA35_FCR_RTSTL_8BYTES);
+ serial_out(up, MA35_LCR_REG, MA35_LCR_WLS_8BITS);
+ serial_out(up, MA35_TOR_REG, MA35_UART_RX_TOUT);
+ serial_out(up, MA35_IER_REG, MA35_IER_RTO_IEN | MA35_IER_RDA_IEN |
+ MA35_IER_TIME_OUT_EN | MA35_IER_BUFERR_IEN);
+ return 0;
+}
+
+static void ma35d1serial_shutdown(struct uart_port *port)
+{
+ struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+ serial_out(up, MA35_IER_REG, 0);
+ free_irq(port->irq, port);
+}
+
+static void ma35d1serial_set_termios(struct uart_port *port,
+ struct ktermios *termios,
+ const struct ktermios *old)
+{
+ struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+ u32 lcr = 0;
+ unsigned long flags;
+ u32 baud, quot;
+
+ lcr = UART_LCR_WLEN(tty_get_char_size(termios->c_cflag));
+
+ if (termios->c_cflag & CSTOPB)
+ lcr |= MA35_LCR_NSB;
+ if (termios->c_cflag & PARENB)
+ lcr |= MA35_LCR_PBE;
+ if (!(termios->c_cflag & PARODD))
+ lcr |= MA35_LCR_EPE;
+ if (termios->c_cflag & CMSPAR)
+ lcr |= MA35_LCR_SPE;
+
+ baud = uart_get_baud_rate(port, termios, old,
+ port->uartclk / MA35_BAUD_DIV_MAX,
+ port->uartclk / MA35_BAUD_DIV_MIN);
+
+ /* MA35D1 UART baud rate equation: baudrate = UART_CLK / (quot + 2) */
+ quot = (port->uartclk / baud) - 2;
+
+ /*
+ * Ok, we're now changing the port state. Do it with
+ * interrupts disabled.
+ */
+ spin_lock_irqsave(&up->port.lock, flags);
+
+ up->port.read_status_mask = MA35_FSR_RX_OVER_IF;
+ if (termios->c_iflag & INPCK)
+ up->port.read_status_mask |= MA35_FSR_FEF | MA35_FSR_PEF;
+ if (termios->c_iflag & (BRKINT | PARMRK))
+ up->port.read_status_mask |= MA35_FSR_BIF;
+
+ /* Characteres to ignore */
+ up->port.ignore_status_mask = 0;
+ if (termios->c_iflag & IGNPAR)
+ up->port.ignore_status_mask |= MA35_FSR_FEF | MA35_FSR_PEF;
+ if (termios->c_iflag & IGNBRK) {
+ up->port.ignore_status_mask |= MA35_FSR_BIF;
+ /*
+ * If we're ignoring parity and break indicators,
+ * ignore overruns too (for real raw support).
+ */
+ if (termios->c_iflag & IGNPAR)
+ up->port.ignore_status_mask |= MA35_FSR_RX_OVER_IF;
+ }
+ if (termios->c_cflag & CRTSCTS)
+ up->mcr |= UART_MCR_AFE;
+ else
+ up->mcr &= ~UART_MCR_AFE;
+
+ uart_update_timeout(port, termios->c_cflag, baud);
+
+ ma35d1serial_set_mctrl(&up->port, up->port.mctrl);
+
+ serial_out(up, MA35_BAUD_REG, MA35_BAUD_MODE2 | FIELD_PREP(MA35_BAUD_MASK, quot));
+
+ serial_out(up, MA35_LCR_REG, lcr);
+
+ spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static const char *ma35d1serial_type(struct uart_port *port)
+{
+ return port->type == PORT_MA35 ? "ma35d1-uart" : NULL;
+}
+
+static void ma35d1serial_config_port(struct uart_port *port, int flags)
+{
+ if (flags & UART_CONFIG_TYPE)
+ port->type = PORT_MA35;
+}
+
+static int ma35d1serial_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+ if (port->type != PORT_UNKNOWN && ser->type != PORT_MA35)
+ return -EINVAL;
+
+ return 0;
+}
+
+static const struct uart_ops ma35d1serial_ops = {
+ .tx_empty = ma35d1serial_tx_empty,
+ .set_mctrl = ma35d1serial_set_mctrl,
+ .get_mctrl = ma35d1serial_get_mctrl,
+ .stop_tx = ma35d1serial_stop_tx,
+ .start_tx = ma35d1serial_start_tx,
+ .stop_rx = ma35d1serial_stop_rx,
+ .break_ctl = ma35d1serial_break_ctl,
+ .startup = ma35d1serial_startup,
+ .shutdown = ma35d1serial_shutdown,
+ .set_termios = ma35d1serial_set_termios,
+ .type = ma35d1serial_type,
+ .config_port = ma35d1serial_config_port,
+ .verify_port = ma35d1serial_verify_port,
+};
+
+static const struct of_device_id ma35d1_serial_of_match[] = {
+ { .compatible = "nuvoton,ma35d1-uart" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, ma35d1_serial_of_match);
+
+#ifdef CONFIG_SERIAL_NUVOTON_MA35D1_CONSOLE
+
+static struct device_node *ma35d1serial_uart_nodes[MA35_UART_NR];
+
+static void wait_for_xmitr(struct uart_ma35d1_port *up)
+{
+ unsigned int tmout;
+
+ /* Wait up to 10ms for the character(s) to be sent. */
+ tmout = 10000;
+ while (--tmout) {
+ if (serial_in(up, MA35_FSR_REG) & MA35_FSR_TX_EMPTY)
+ break;
+ udelay(1);
+ }
+}
+
+static void ma35d1serial_console_putchar(struct uart_port *port, unsigned char ch)
+{
+ struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+ wait_for_xmitr(up);
+ serial_out(up, MA35_THR_REG, ch);
+}
+
+/*
+ * Print a string to the serial port trying not to disturb
+ * any possible real use of the port...
+ *
+ * The console_lock must be held when we get here.
+ */
+static void ma35d1serial_console_write(struct console *co, const char *s, u32 count)
+{
+ struct uart_ma35d1_port *up = &ma35d1serial_ports[co->index];
+ unsigned long flags;
+ int locked = 1;
+ u32 ier;
+
+ if (up->port.sysrq)
+ locked = 0;
+ else if (oops_in_progress)
+ locked = spin_trylock_irqsave(&up->port.lock, flags);
+ else
+ spin_lock_irqsave(&up->port.lock, flags);
+
+ /*
+ * First save the IER then disable the interrupts
+ */
+ ier = serial_in(up, MA35_IER_REG);
+ serial_out(up, MA35_IER_REG, 0);
+
+ uart_console_write(&up->port, s, count, ma35d1serial_console_putchar);
+
+ wait_for_xmitr(up);
+ serial_out(up, MA35_IER_REG, ier);
+
+ if (locked)
+ spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static int __init ma35d1serial_console_setup(struct console *co, char *options)
+{
+ struct device_node *np;
+ struct uart_ma35d1_port *p;
+ u32 val32[4];
+ struct uart_port *port;
+ int baud = 115200;
+ int bits = 8;
+ int parity = 'n';
+ int flow = 'n';
+
+ if ((co->index < 0) || (co->index >= MA35_UART_NR)) {
+ pr_debug("Console Port%x out of range\n", co->index);
+ return -EINVAL;
+ }
+
+ np = ma35d1serial_uart_nodes[co->index];
+ p = &ma35d1serial_ports[co->index];
+ if (!np || !p)
+ return -ENODEV;
+
+ if (of_property_read_u32_array(np, "reg", val32, ARRAY_SIZE(val32)) != 0)
+ return -EINVAL;
+
+ p->port.iobase = val32[1];
+ p->port.membase = ioremap(p->port.iobase, MA35_UART_REG_SIZE);
+ if (!p->port.membase)
+ return -ENOMEM;
+
+ p->port.ops = &ma35d1serial_ops;
+ p->port.line = 0;
+ p->port.uartclk = MA35_UART_CONSOLE_CLK;
+
+ port = &ma35d1serial_ports[co->index].port;
+
+ if (options)
+ uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+ return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct console ma35d1serial_console = {
+ .name = "ttyNVT",
+ .write = ma35d1serial_console_write,
+ .device = uart_console_device,
+ .setup = ma35d1serial_console_setup,
+ .flags = CON_PRINTBUFFER | CON_ENABLED,
+ .index = -1,
+ .data = &ma35d1serial_reg,
+};
+
+static void ma35d1serial_console_init_port(void)
+{
+ u32 i = 0;
+ struct device_node *np;
+
+ for_each_matching_node(np, ma35d1_serial_of_match) {
+ if (ma35d1serial_uart_nodes[i] == NULL) {
+ of_node_get(np);
+ ma35d1serial_uart_nodes[i] = np;
+ i++;
+ if (i == MA35_UART_NR)
+ break;
+ }
+ }
+}
+
+static int __init ma35d1serial_console_init(void)
+{
+ ma35d1serial_console_init_port();
+ register_console(&ma35d1serial_console);
+ return 0;
+}
+console_initcall(ma35d1serial_console_init);
+
+#define MA35D1SERIAL_CONSOLE (&ma35d1serial_console)
+#else
+#define MA35D1SERIAL_CONSOLE NULL
+#endif
+
+static struct uart_driver ma35d1serial_reg = {
+ .owner = THIS_MODULE,
+ .driver_name = "serial",
+ .dev_name = "ttyNVT",
+ .major = TTY_MAJOR,
+ .minor = 64,
+ .cons = MA35D1SERIAL_CONSOLE,
+ .nr = MA35_UART_NR,
+};
+
+/*
+ * Register a set of serial devices attached to a platform device.
+ * The list is terminated with a zero flags entry, which means we expect
+ * all entries to have at least UPF_BOOT_AUTOCONF set.
+ */
+static int ma35d1serial_probe(struct platform_device *pdev)
+{
+ struct resource *res_mem;
+ struct uart_ma35d1_port *up;
+ int ret = 0;
+
+ if (pdev->dev.of_node) {
+ ret = of_alias_get_id(pdev->dev.of_node, "serial");
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to get alias/pdev id, errno %d\n", ret);
+ return ret;
+ }
+ }
+ up = &ma35d1serial_ports[ret];
+ up->port.line = ret;
+ res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res_mem)
+ return -ENODEV;
+
+ up->port.iobase = res_mem->start;
+ up->port.membase = ioremap(up->port.iobase, MA35_UART_REG_SIZE);
+ up->port.ops = &ma35d1serial_ops;
+
+ spin_lock_init(&up->port.lock);
+
+ up->clk = of_clk_get(pdev->dev.of_node, 0);
+ if (IS_ERR(up->clk)) {
+ ret = PTR_ERR(up->clk);
+ dev_err(&pdev->dev, "failed to get core clk: %d\n", ret);
+ goto err_iounmap;
+ }
+
+ ret = clk_prepare_enable(up->clk);
+ if (ret)
+ goto err_iounmap;
+
+ if (up->port.line != 0)
+ up->port.uartclk = clk_get_rate(up->clk);
+
+ ret = platform_get_irq(pdev, 0);
+ if (ret < 0)
+ goto err_clk_disable;
+
+ up->port.irq = ret;
+ up->port.dev = &pdev->dev;
+ up->port.flags = UPF_BOOT_AUTOCONF;
+
+ platform_set_drvdata(pdev, up);
+
+ ret = uart_add_one_port(&ma35d1serial_reg, &up->port);
+ if (ret < 0)
+ goto err_free_irq;
+
+ return 0;
+
+err_free_irq:
+ free_irq(up->port.irq, &up->port);
+
+err_clk_disable:
+ clk_disable_unprepare(up->clk);
+
+err_iounmap:
+ iounmap(up->port.membase);
+ return ret;
+}
+
+/*
+ * Remove serial ports registered against a platform device.
+ */
+static int ma35d1serial_remove(struct platform_device *dev)
+{
+ struct uart_port *port = platform_get_drvdata(dev);
+ struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+ uart_remove_one_port(&ma35d1serial_reg, port);
+ clk_disable_unprepare(up->clk);
+ return 0;
+}
+
+static int ma35d1serial_suspend(struct platform_device *dev, pm_message_t state)
+{
+ struct uart_port *port = platform_get_drvdata(dev);
+ struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+ uart_suspend_port(&ma35d1serial_reg, &up->port);
+ if (up->port.line == 0) {
+ up->console_baud_rate = serial_in(up, MA35_BAUD_REG);
+ up->console_line = serial_in(up, MA35_LCR_REG);
+ up->console_int = serial_in(up, MA35_IER_REG);
+ }
+ return 0;
+}
+
+static int ma35d1serial_resume(struct platform_device *dev)
+{
+ struct uart_port *port = platform_get_drvdata(dev);
+ struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
+
+ if (up->port.line == 0) {
+ serial_out(up, MA35_BAUD_REG, up->console_baud_rate);
+ serial_out(up, MA35_LCR_REG, up->console_line);
+ serial_out(up, MA35_IER_REG, up->console_int);
+ }
+ uart_resume_port(&ma35d1serial_reg, &up->port);
+ return 0;
+}
+
+static struct platform_driver ma35d1serial_driver = {
+ .probe = ma35d1serial_probe,
+ .remove = ma35d1serial_remove,
+ .suspend = ma35d1serial_suspend,
+ .resume = ma35d1serial_resume,
+ .driver = {
+ .name = "ma35d1-uart",
+ .owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(ma35d1_serial_of_match),
+ },
+};
+
+static int __init ma35d1serial_init(void)
+{
+ int ret;
+
+ ret = uart_register_driver(&ma35d1serial_reg);
+ if (ret)
+ return ret;
+
+ ret = platform_driver_register(&ma35d1serial_driver);
+ if (ret)
+ uart_unregister_driver(&ma35d1serial_reg);
+
+ return ret;
+}
+
+static void __exit ma35d1serial_exit(void)
+{
+ platform_driver_unregister(&ma35d1serial_driver);
+ uart_unregister_driver(&ma35d1serial_reg);
+}
+
+module_init(ma35d1serial_init);
+module_exit(ma35d1serial_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("MA35D1 serial driver");
diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
index 281fa286555c..c11600bb1b0d 100644
--- a/include/uapi/linux/serial_core.h
+++ b/include/uapi/linux/serial_core.h
@@ -279,4 +279,7 @@
/* Sunplus UART */
#define PORT_SUNPLUS 123

+/* Nuvoton MA35 SoC */
+#define PORT_MA35 124
+
#endif /* _UAPILINUX_SERIAL_CORE_H */
--
2.34.1
Re: [PATCH v13 10/10] tty: serial: Add Nuvoton ma35d1 serial driver support [ In reply to ]
On Mon, 5 Jun 2023, Jacky Huang wrote:

> From: Jacky Huang <ychuang3@nuvoton.com>
>
> This adds UART and console driver for Nuvoton ma35d1 Soc.
> It supports full-duplex communication, FIFO control, and
> hardware flow control.
>
> Signed-off-by: Jacky Huang <ychuang3@nuvoton.com>

A few stylistic things below, should be easy to address them I think. In
general, this is in quite good shape already.

> ---
> drivers/tty/serial/Kconfig | 18 +
> drivers/tty/serial/Makefile | 1 +
> drivers/tty/serial/ma35d1_serial.c | 808 +++++++++++++++++++++++++++++
> include/uapi/linux/serial_core.h | 3 +
> 4 files changed, 830 insertions(+)
> create mode 100644 drivers/tty/serial/ma35d1_serial.c
>
> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
> index 3e3fb377d90d..71ea5138adce 100644
> --- a/drivers/tty/serial/Kconfig
> +++ b/drivers/tty/serial/Kconfig
> @@ -1555,6 +1555,24 @@ config SERIAL_SUNPLUS_CONSOLE
> you can alter that using a kernel command line option such as
> "console=ttySUPx".
>
> +config SERIAL_NUVOTON_MA35D1
> + tristate "Nuvoton MA35D1 family UART support"
> + depends on ARCH_MA35 || COMPILE_TEST
> + select SERIAL_CORE
> + help
> + This driver supports Nuvoton MA35D1 family UART ports. If you would
> + like to use them, you must answer Y or M to this option. Note that
> + for use as console, it must be included in kernel and not as a
> + module
> +
> +config SERIAL_NUVOTON_MA35D1_CONSOLE
> + bool "Console on a Nuvotn MA35D1 family UART port"
> + depends on SERIAL_NUVOTON_MA35D1=y
> + select SERIAL_CORE_CONSOLE
> + help
> + Select this options if you'd like to use the UART port0 of the
> + Nuvoton MA35D1 family as a console.
> +
> endmenu
>
> config SERIAL_MCTRL_GPIO
> diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
> index cd9afd9e3018..0e823851c42c 100644
> --- a/drivers/tty/serial/Makefile
> +++ b/drivers/tty/serial/Makefile
> @@ -93,3 +93,4 @@ obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o
>
> obj-$(CONFIG_SERIAL_KGDB_NMI) += kgdb_nmi.o
> obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o
> +obj-$(CONFIG_SERIAL_NUVOTON_MA35D1) += ma35d1_serial.o
> diff --git a/drivers/tty/serial/ma35d1_serial.c b/drivers/tty/serial/ma35d1_serial.c
> new file mode 100644
> index 000000000000..6c19da7731a6
> --- /dev/null
> +++ b/drivers/tty/serial/ma35d1_serial.c
> @@ -0,0 +1,808 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * MA35D1 serial driver
> + * Copyright (C) 2023 Nuvoton Technology Corp.
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/of.h>
> +#include <linux/of_platform.h>
> +#include <linux/serial_core.h>
> +#include <linux/slab.h>
> +#include <linux/tty_flip.h>
> +#include <linux/units.h>
> +
> +#define MA35_UART_NR 17
> +
> +#define MA35_RBR_REG 0x00
> +#define MA35_THR_REG 0x00
> +#define MA35_IER_REG 0x04
> +#define MA35_FCR_REG 0x08
> +#define MA35_LCR_REG 0x0C
> +#define MA35_MCR_REG 0x10
> +#define MA35_MSR_REG 0x14
> +#define MA35_FSR_REG 0x18
> +#define MA35_ISR_REG 0x1C
> +#define MA35_TOR_REG 0x20
> +#define MA35_BAUD_REG 0x24
> +#define MA35_ALTCTL_REG 0x2C
> +#define MA35_FUN_SEL_REG 0x30
> +#define MA35_WKCTL_REG 0x40
> +#define MA35_WKSTS_REG 0x44
> +
> +/* MA35_IER_REG - Interrupt Enable Register */
> +#define MA35_IER_RDA_IEN BIT(0) /* RBR Available Interrupt Enable */
> +#define MA35_IER_THRE_IEN BIT(1) /* THR Empty Interrupt Enable */
> +#define MA35_IER_RLS_IEN BIT(2) /* RX Line Status Interrupt Enable */
> +#define MA35_IER_RTO_IEN BIT(4) /* RX Time-out Interrupt Enable */
> +#define MA35_IER_BUFERR_IEN BIT(5) /* Buffer Error Interrupt Enable */
> +#define MA35_IER_TIME_OUT_EN BIT(11) /* RX Buffer Time-out Counter Enable */
> +#define MA35_IER_AUTO_RTS BIT(12) /* nRTS Auto-flow Control Enable */
> +#define MA35_IER_AUTO_CTS BIT(13) /* nCTS Auto-flow Control Enable */
> +
> +/* MA35_FCR_REG - FIFO Control Register */
> +#define MA35_FCR_RFR BIT(1) /* RX Field Software Reset */
> +#define MA35_FCR_TFR BIT(2) /* TX Field Software Reset */
> +#define MA35_FCR_RFITL_MASK GENMASK(7, 4) /* RX FIFO Interrupt Trigger Level */
> +#define MA35_FCR_RFITL_1BYTE FIELD_PREP(MA35_FCR_RFITL_MASK, 0)
> +#define MA35_FCR_RFITL_4BYTES FIELD_PREP(MA35_FCR_RFITL_MASK, 1)
> +#define MA35_FCR_RFITL_8BYTES FIELD_PREP(MA35_FCR_RFITL_MASK, 2)
> +#define MA35_FCR_RFITL_14BYTES FIELD_PREP(MA35_FCR_RFITL_MASK, 3)
> +#define MA35_FCR_RFITL_30BYTES FIELD_PREP(MA35_FCR_RFITL_MASK, 4)
> +#define MA35_FCR_RTSTL_MASK GENMASK(19, 16) /* nRTS Trigger Level */
> +#define MA35_FCR_RTSTL_1BYTE FIELD_PREP(MA35_FCR_RTSTL_MASK, 0)
> +#define MA35_FCR_RTSTL_4BYTES FIELD_PREP(MA35_FCR_RTSTL_MASK, 1)
> +#define MA35_FCR_RTSTL_8BYTES FIELD_PREP(MA35_FCR_RTSTL_MASK, 2)
> +#define MA35_FCR_RTSTL_14BYTES FIELD_PREP(MA35_FCR_RTSTL_MASK, 3)
> +#define MA35_FCR_RTSTLL_30BYTES FIELD_PREP(MA35_FCR_RTSTL_MASK, 4)
> +
> +/* MA35_LCR_REG - Line Control Register */
> +#define MA35_LCR_NSB BIT(2) /* Number of “STOP Bit” */
> +#define MA35_LCR_PBE BIT(3) /* Parity Bit Enable */
> +#define MA35_LCR_EPE BIT(4) /* Even Parity Enable */
> +#define MA35_LCR_SPE BIT(5) /* Stick Parity Enable */
> +#define MA35_LCR_BREAK BIT(6) /* Break Control */
> +#define MA35_LCR_WLS_MASK GENMASK(1, 0) /* Word Length Selection */
> +#define MA35_LCR_WLS_5BITS FIELD_PREP(MA35_LCR_WLS_MASK, 0)
> +#define MA35_LCR_WLS_6BITS FIELD_PREP(MA35_LCR_WLS_MASK, 1)
> +#define MA35_LCR_WLS_7BITS FIELD_PREP(MA35_LCR_WLS_MASK, 2)
> +#define MA35_LCR_WLS_8BITS FIELD_PREP(MA35_LCR_WLS_MASK, 3)
> +
> +/* MA35_MCR_REG - Modem Control Register */
> +#define MA35_MCR_RTS_CTRL BIT(1) /* nRTS Signal Control */
> +#define MA35_MCR_RTSACTLV BIT(9) /* nRTS Pin Active Level */
> +#define MA35_MCR_RTSSTS BIT(13) /* nRTS Pin Status (Read Only) */
> +
> +/* MA35_MSR_REG - Modem Status Register */
> +#define MA35_MSR_CTSDETF BIT(0) /* Detect nCTS State Change Flag */
> +#define MA35_MSR_CTSSTS BIT(4) /* nCTS Pin Status (Read Only) */
> +#define MA35_MSR_CTSACTLV BIT(8) /* nCTS Pin Active Level */
> +
> +/* MA35_FSR_REG - FIFO Status Register */
> +#define MA35_FSR_RX_OVER_IF BIT(0) /* RX Overflow Error Interrupt Flag */
> +#define MA35_FSR_PEF BIT(4) /* Parity Error Flag*/
> +#define MA35_FSR_FEF BIT(5) /* Framing Error Flag */
> +#define MA35_FSR_BIF BIT(6) /* Break Interrupt Flag */
> +#define MA35_FSR_RX_EMPTY BIT(14) /* Receiver FIFO Empty (Read Only) */
> +#define MA35_FSR_RX_FULL BIT(15) /* Receiver FIFO Full (Read Only) */
> +#define MA35_FSR_TX_EMPTY BIT(22) /* Transmitter FIFO Empty (Read Only) */
> +#define MA35_FSR_TX_FULL BIT(23) /* Transmitter FIFO Full (Read Only) */
> +#define MA35_FSR_TX_OVER_IF BIT(24) /* TX Overflow Error Interrupt Flag */
> +#define MA35_FSR_TE_FLAG BIT(28) /* Transmitter Empty Flag (Read Only) */
> +#define MA35_FSR_RXPTR_MSK GENMASK(13, 8) /* TX FIFO Pointer mask */
> +#define MA35_FSR_TXPTR_MSK GENMASK(21, 16) /* RX FIFO Pointer mask */
> +
> +/* MA35_ISR_REG - Interrupt Status Register */
> +#define MA35_ISR_RDA_IF BIT(0) /* RBR Available Interrupt Flag */
> +#define MA35_ISR_THRE_IF BIT(1) /* THR Empty Interrupt Flag */
> +#define MA35_ISR_RLSIF BIT(2) /* Receive Line Interrupt Flag */
> +#define MA35_ISR_MODEMIF BIT(3) /* MODEM Interrupt Flag */
> +#define MA35_ISR_RXTO_IF BIT(4) /* RX Time-out Interrupt Flag */
> +#define MA35_ISR_BUFEIF BIT(5) /* Buffer Error Interrupt Flag */
> +#define MA35_ISR_WK_IF BIT(6) /* UART Wake-up Interrupt Flag */
> +#define MA35_ISR_RDAINT BIT(8) /* RBR Available Interrupt Indicator */
> +#define MA35_ISR_THRE_INT BIT(9) /* THR Empty Interrupt Indicator */
> +#define MA35_ISR_ALL 0xFFFFFFFF
> +
> +/* MA35_BAUD_REG - Baud Rate Divider Register */
> +#define MA35_BAUD_MODE_MASK GENMASK(29, 28)
> +#define MA35_BAUD_MODE0 FIELD_PREP(MA35_BAUD_MODE_MASK, 0)
> +#define MA35_BAUD_MODE1 FIELD_PREP(MA35_BAUD_MODE_MASK, 2)
> +#define MA35_BAUD_MODE2 FIELD_PREP(MA35_BAUD_MODE_MASK, 3)
> +#define MA35_BAUD_MASK GENMASK(15, 0)
> +
> +/* MA35_ALTCTL_REG - Alternate Control/Status Register */
> +#define MA35_ALTCTL_RS485AUD BIT(10) /* RS-485 Auto Direction Function */
> +
> +/* MA35_FUN_SEL_REG - Function Select Register */
> +#define MA35_FUN_SEL_MASK GENMASK(2, 0)
> +#define MA35_FUN_SEL_UART FIELD_PREP(MA35_FUN_SEL_MASK, 0)
> +#define MA35_FUN_SEL_RS485 FIELD_PREP(MA35_FUN_SEL_MASK, 3)
> +
> +/* The constrain for MA35D1 UART baud rate divider */
> +#define MA35_BAUD_DIV_MAX 0xFFFF
> +#define MA35_BAUD_DIV_MIN 11
> +
> +/* UART FIFO depth */
> +#define MA35_UART_FIFO_DEPTH 32
> +/* UART console clock */
> +#define MA35_UART_CONSOLE_CLK (24 * HZ_PER_MHZ)
> +/* UART register ioremap size */
> +#define MA35_UART_REG_SIZE 0x100
> +/* Rx Timeout */
> +#define MA35_UART_RX_TOUT 0x40
> +
> +#define MA35_ISR_IF_CHECK (MA35_ISR_RDA_IF | MA35_ISR_RXTO_IF | \
> + MA35_ISR_THRE_INT | MA35_ISR_BUFEIF)
> +
> +static struct uart_driver ma35d1serial_reg;
> +
> +struct uart_ma35d1_port {
> + struct uart_port port;
> + struct clk *clk;
> + u16 capabilities; /* port capabilities */
> + u8 ier;
> + u8 lcr;
> + u8 mcr;
> + u32 baud_rate;
> + u32 console_baud_rate;
> + u32 console_line;
> + u32 console_int;
> +};
> +
> +static struct uart_ma35d1_port ma35d1serial_ports[MA35_UART_NR];
> +
> +static struct uart_ma35d1_port *to_ma35d1_uart_port(struct uart_port *uart)
> +{
> + return container_of(uart, struct uart_ma35d1_port, port);
> +}
> +
> +static u32 serial_in(struct uart_ma35d1_port *p, u32 offset)
> +{
> + return readl_relaxed(p->port.membase + offset);
> +}
> +
> +static void serial_out(struct uart_ma35d1_port *p, u32 offset, u32 value)
> +{
> + writel_relaxed(value, p->port.membase + offset);
> +}
> +
> +static void __stop_tx(struct uart_ma35d1_port *p)
> +{
> + u32 ier;
> +
> + ier = serial_in(p, MA35_IER_REG);
> + if (ier & MA35_IER_THRE_IEN)
> + serial_out(p, MA35_IER_REG, ier & ~MA35_IER_THRE_IEN);
> +}
> +
> +static void ma35d1serial_stop_tx(struct uart_port *port)
> +{
> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
> +
> + __stop_tx(up);
> +}
> +
> +static void transmit_chars(struct uart_ma35d1_port *up)
> +{
> + u32 count;
> + u8 ch;
> +
> + if (uart_tx_stopped(&up->port)) {
> + ma35d1serial_stop_tx(&up->port);
> + return;
> + }
> + count = MA35_UART_FIFO_DEPTH - FIELD_GET(MA35_FSR_TXPTR_MSK,
> + serial_in(up, MA35_FSR_REG));
> + uart_port_tx_limited(&up->port, ch, count,
> + !(serial_in(up, MA35_FSR_REG) & MA35_FSR_TX_FULL),
> + serial_out(up, MA35_THR_REG, ch),
> + ({}));
> +}
> +
> +static void ma35d1serial_start_tx(struct uart_port *port)
> +{
> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
> + u32 ier;
> +
> + ier = serial_in(up, MA35_IER_REG);
> + serial_out(up, MA35_IER_REG, ier & ~MA35_IER_THRE_IEN);
> + transmit_chars(up);
> + serial_out(up, MA35_IER_REG, ier | MA35_IER_THRE_IEN);
> +}
> +
> +static void ma35d1serial_stop_rx(struct uart_port *port)
> +{
> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
> +
> + serial_out(up, MA35_IER_REG, serial_in(up, MA35_IER_REG) & ~MA35_IER_RDA_IEN);

These should be split up to:
reg = serial_in(...)
reg &= ~MA35_IER_RDA_IEN;
serial_out(...)

There are other cases too besides this one, convert them all. It will help
with some line splitting challenges too you seem to have below.

> +}
> +
> +static void receive_chars(struct uart_ma35d1_port *up)
> +{
> + u8 ch, flag;
> + u32 fsr;
> + int max_count = 256;
> +
> + fsr = serial_in(up, MA35_FSR_REG);
> + do {
> + flag = TTY_NORMAL;
> + up->port.icount.rx++;
> +
> + if (unlikely(fsr & (MA35_FSR_BIF | MA35_FSR_FEF |
> + MA35_FSR_PEF | MA35_FSR_RX_OVER_IF))) {
> + if (fsr & MA35_FSR_BIF) {
> + up->port.icount.brk++;
> + if (uart_handle_break(&up->port))
> + continue;
> + }
> + if (fsr & MA35_FSR_FEF)
> + up->port.icount.frame++;
> + if (fsr & MA35_FSR_PEF)
> + up->port.icount.parity++;
> + if (fsr & MA35_FSR_RX_OVER_IF)
> + up->port.icount.overrun++;
> +
> + serial_out(up, MA35_FSR_REG,
> + fsr & (MA35_FSR_BIF | MA35_FSR_FEF |
> + MA35_FSR_PEF | MA35_FSR_RX_OVER_IF));
> + if (fsr & MA35_FSR_BIF)
> + flag = TTY_BREAK;
> + else if (fsr & MA35_FSR_PEF)
> + flag = TTY_PARITY;
> + else if (fsr & MA35_FSR_FEF)
> + flag = TTY_FRAME;
> + }
> +
> + ch = serial_in(up, MA35_RBR_REG);
> + if (uart_handle_sysrq_char(&up->port, ch))
> + continue;
> +
> + spin_lock(&up->port.lock);
> + uart_insert_char(&up->port, fsr, MA35_FSR_RX_OVER_IF, ch, flag);
> + spin_unlock(&up->port.lock);
> +
> + fsr = serial_in(up, MA35_FSR_REG);
> + } while (!(fsr & MA35_FSR_RX_EMPTY) && (max_count-- > 0));
> +
> + spin_lock(&up->port.lock);
> + tty_flip_buffer_push(&up->port.state->port);
> + spin_unlock(&up->port.lock);
> +}
> +
> +static irqreturn_t ma35d1serial_interrupt(int irq, void *dev_id)
> +{
> + struct uart_port *port = dev_id;
> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
> + u32 isr, fsr;
> +
> + isr = serial_in(up, MA35_ISR_REG);
> + fsr = serial_in(up, MA35_FSR_REG);
> +
> + if (!(isr & MA35_ISR_IF_CHECK))
> + return IRQ_NONE;
> +
> + if (isr & (MA35_ISR_RDA_IF | MA35_ISR_RXTO_IF))
> + receive_chars(up);
> + if (isr & MA35_ISR_THRE_INT)
> + transmit_chars(up);
> + if (fsr & MA35_FSR_TX_OVER_IF)
> + serial_out(up, MA35_FSR_REG, MA35_FSR_TX_OVER_IF);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static u32 ma35d1serial_tx_empty(struct uart_port *port)
> +{
> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
> + u32 fsr;
> +
> + fsr = serial_in(up, MA35_FSR_REG);
> + return (fsr & (MA35_FSR_TE_FLAG | MA35_FSR_TX_EMPTY)) ==
> + (MA35_FSR_TE_FLAG | MA35_FSR_TX_EMPTY) ? TIOCSER_TEMT : 0;

To make this check cleaner, add this and use it here:

#define MA35_FSR_TX_BOTH_EMPTY (MA35_FSR_TE_FLAG | MA35_FSR_TX_EMPTY)

> +}
> +
> +static u32 ma35d1serial_get_mctrl(struct uart_port *port)
> +{
> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
> + u32 status;
> + u32 ret = 0;
> +
> + status = serial_in(up, MA35_MSR_REG);
> + if (!(status & MA35_MSR_CTSSTS))
> + ret |= TIOCM_CTS;
> + return ret;
> +}
> +
> +static void ma35d1serial_set_mctrl(struct uart_port *port, u32 mctrl)
> +{
> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
> + u32 mcr;
> + u32 ier;
> +
> + mcr = serial_in(up, MA35_MCR_REG);
> + mcr &= ~MA35_MCR_RTS_CTRL;
> +
> + if (mctrl & TIOCM_RTS)
> + mcr |= MA35_MCR_RTSACTLV;
> + else
> + mcr &= ~MA35_MCR_RTSACTLV;
> +
> + if (up->mcr & UART_MCR_AFE) {
> + serial_out(up, MA35_IER_REG, (serial_in(up, MA35_IER_REG) |
> + MA35_IER_AUTO_RTS |
> + MA35_IER_AUTO_CTS));
> + up->port.flags |= UPF_HARD_FLOW;
> + } else {
> + ier = serial_in(up, MA35_IER_REG);
> + ier &= ~(MA35_IER_AUTO_RTS | MA35_IER_AUTO_CTS);
> + serial_out(up, MA35_IER_REG, ier);
> + up->port.flags &= ~UPF_HARD_FLOW;
> + }
> + serial_out(up, MA35_MSR_REG, (serial_in(up, MA35_MSR_REG) |
> + MA35_MSR_CTSACTLV));
> + serial_out(up, MA35_MCR_REG, mcr);
> +}
> +
> +static void ma35d1serial_break_ctl(struct uart_port *port, int break_state)
> +{
> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
> + unsigned long flags;
> + u32 lcr;
> +
> + spin_lock_irqsave(&up->port.lock, flags);
> + lcr = serial_in(up, MA35_LCR_REG);
> + if (break_state != 0)
> + lcr |= MA35_LCR_BREAK;
> + else
> + lcr &= ~MA35_LCR_BREAK;
> + serial_out(up, MA35_LCR_REG, lcr);
> + spin_unlock_irqrestore(&up->port.lock, flags);
> +}
> +
> +static int ma35d1serial_startup(struct uart_port *port)
> +{
> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
> + int retval;
> +
> + /* Reset FIFO */
> + serial_out(up, MA35_FCR_REG, MA35_FCR_TFR | MA35_FCR_RFR);
> +
> + /* Clear pending interrupts */
> + serial_out(up, MA35_ISR_REG, MA35_ISR_ALL);
> +
> + retval = request_irq(port->irq, ma35d1serial_interrupt, 0,
> + dev_name(port->dev), port);
> + if (retval) {
> + dev_err(up->port.dev, "request irq failed.\n");
> + return retval;
> + }
> +
> + serial_out(up, MA35_FCR_REG, serial_in(up, MA35_FCR_REG) |
> + MA35_FCR_RFITL_4BYTES | MA35_FCR_RTSTL_8BYTES);
> + serial_out(up, MA35_LCR_REG, MA35_LCR_WLS_8BITS);
> + serial_out(up, MA35_TOR_REG, MA35_UART_RX_TOUT);
> + serial_out(up, MA35_IER_REG, MA35_IER_RTO_IEN | MA35_IER_RDA_IEN |
> + MA35_IER_TIME_OUT_EN | MA35_IER_BUFERR_IEN);

Align to the parameter like this:
serial_out(up, MA35_IER_REG, MA35_IER_RTO_IEN | MA35_IER_RDA_IEN |
MA35_IER_TIME_OUT_EN | MA35_IER_BUFERR_IEN);


> + return 0;
> +}
> +
> +static void ma35d1serial_shutdown(struct uart_port *port)
> +{
> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
> +
> + serial_out(up, MA35_IER_REG, 0);
> + free_irq(port->irq, port);
> +}
> +
> +static void ma35d1serial_set_termios(struct uart_port *port,
> + struct ktermios *termios,
> + const struct ktermios *old)
> +{
> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
> + u32 lcr = 0;
> + unsigned long flags;
> + u32 baud, quot;
> +
> + lcr = UART_LCR_WLEN(tty_get_char_size(termios->c_cflag));
> +
> + if (termios->c_cflag & CSTOPB)
> + lcr |= MA35_LCR_NSB;
> + if (termios->c_cflag & PARENB)
> + lcr |= MA35_LCR_PBE;
> + if (!(termios->c_cflag & PARODD))
> + lcr |= MA35_LCR_EPE;
> + if (termios->c_cflag & CMSPAR)
> + lcr |= MA35_LCR_SPE;
> +
> + baud = uart_get_baud_rate(port, termios, old,
> + port->uartclk / MA35_BAUD_DIV_MAX,
> + port->uartclk / MA35_BAUD_DIV_MIN);
> +
> + /* MA35D1 UART baud rate equation: baudrate = UART_CLK / (quot + 2) */
> + quot = (port->uartclk / baud) - 2;
> +
> + /*
> + * Ok, we're now changing the port state. Do it with
> + * interrupts disabled.
> + */
> + spin_lock_irqsave(&up->port.lock, flags);
> +
> + up->port.read_status_mask = MA35_FSR_RX_OVER_IF;
> + if (termios->c_iflag & INPCK)
> + up->port.read_status_mask |= MA35_FSR_FEF | MA35_FSR_PEF;
> + if (termios->c_iflag & (BRKINT | PARMRK))
> + up->port.read_status_mask |= MA35_FSR_BIF;
> +
> + /* Characteres to ignore */
> + up->port.ignore_status_mask = 0;
> + if (termios->c_iflag & IGNPAR)
> + up->port.ignore_status_mask |= MA35_FSR_FEF | MA35_FSR_PEF;
> + if (termios->c_iflag & IGNBRK) {
> + up->port.ignore_status_mask |= MA35_FSR_BIF;
> + /*
> + * If we're ignoring parity and break indicators,
> + * ignore overruns too (for real raw support).
> + */
> + if (termios->c_iflag & IGNPAR)
> + up->port.ignore_status_mask |= MA35_FSR_RX_OVER_IF;
> + }
> + if (termios->c_cflag & CRTSCTS)
> + up->mcr |= UART_MCR_AFE;
> + else
> + up->mcr &= ~UART_MCR_AFE;
> +
> + uart_update_timeout(port, termios->c_cflag, baud);
> +
> + ma35d1serial_set_mctrl(&up->port, up->port.mctrl);
> +
> + serial_out(up, MA35_BAUD_REG, MA35_BAUD_MODE2 | FIELD_PREP(MA35_BAUD_MASK, quot));
> +
> + serial_out(up, MA35_LCR_REG, lcr);
> +
> + spin_unlock_irqrestore(&up->port.lock, flags);
> +}
> +
> +static const char *ma35d1serial_type(struct uart_port *port)
> +{
> + return port->type == PORT_MA35 ? "ma35d1-uart" : NULL;
> +}
> +
> +static void ma35d1serial_config_port(struct uart_port *port, int flags)
> +{
> + if (flags & UART_CONFIG_TYPE)
> + port->type = PORT_MA35;
> +}
> +
> +static int ma35d1serial_verify_port(struct uart_port *port, struct serial_struct *ser)
> +{
> + if (port->type != PORT_UNKNOWN && ser->type != PORT_MA35)
> + return -EINVAL;
> +
> + return 0;
> +}
> +
> +static const struct uart_ops ma35d1serial_ops = {
> + .tx_empty = ma35d1serial_tx_empty,
> + .set_mctrl = ma35d1serial_set_mctrl,
> + .get_mctrl = ma35d1serial_get_mctrl,
> + .stop_tx = ma35d1serial_stop_tx,
> + .start_tx = ma35d1serial_start_tx,
> + .stop_rx = ma35d1serial_stop_rx,
> + .break_ctl = ma35d1serial_break_ctl,
> + .startup = ma35d1serial_startup,
> + .shutdown = ma35d1serial_shutdown,
> + .set_termios = ma35d1serial_set_termios,
> + .type = ma35d1serial_type,
> + .config_port = ma35d1serial_config_port,
> + .verify_port = ma35d1serial_verify_port,
> +};
> +
> +static const struct of_device_id ma35d1_serial_of_match[] = {
> + { .compatible = "nuvoton,ma35d1-uart" },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, ma35d1_serial_of_match);
> +
> +#ifdef CONFIG_SERIAL_NUVOTON_MA35D1_CONSOLE
> +
> +static struct device_node *ma35d1serial_uart_nodes[MA35_UART_NR];
> +
> +static void wait_for_xmitr(struct uart_ma35d1_port *up)
> +{
> + unsigned int tmout;
> +
> + /* Wait up to 10ms for the character(s) to be sent. */
> + tmout = 10000;
> + while (--tmout) {
> + if (serial_in(up, MA35_FSR_REG) & MA35_FSR_TX_EMPTY)
> + break;
> + udelay(1);
> + }

This can be written as:

unsigned int reg;

read_poll_timeout_atomic(serial_in, reg, reg & MA35_FSR_TX_EMPTY,
1, 10000, false,
up, MA35_FSR_REG);


--
i.

> +}
> +
> +static void ma35d1serial_console_putchar(struct uart_port *port, unsigned char ch)
> +{
> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
> +
> + wait_for_xmitr(up);
> + serial_out(up, MA35_THR_REG, ch);
> +}
> +
> +/*
> + * Print a string to the serial port trying not to disturb
> + * any possible real use of the port...
> + *
> + * The console_lock must be held when we get here.
> + */
> +static void ma35d1serial_console_write(struct console *co, const char *s, u32 count)
> +{
> + struct uart_ma35d1_port *up = &ma35d1serial_ports[co->index];
> + unsigned long flags;
> + int locked = 1;
> + u32 ier;
> +
> + if (up->port.sysrq)
> + locked = 0;
> + else if (oops_in_progress)
> + locked = spin_trylock_irqsave(&up->port.lock, flags);
> + else
> + spin_lock_irqsave(&up->port.lock, flags);
> +
> + /*
> + * First save the IER then disable the interrupts
> + */
> + ier = serial_in(up, MA35_IER_REG);
> + serial_out(up, MA35_IER_REG, 0);
> +
> + uart_console_write(&up->port, s, count, ma35d1serial_console_putchar);
> +
> + wait_for_xmitr(up);
> + serial_out(up, MA35_IER_REG, ier);
> +
> + if (locked)
> + spin_unlock_irqrestore(&up->port.lock, flags);
> +}
> +
> +static int __init ma35d1serial_console_setup(struct console *co, char *options)
> +{
> + struct device_node *np;
> + struct uart_ma35d1_port *p;
> + u32 val32[4];
> + struct uart_port *port;
> + int baud = 115200;
> + int bits = 8;
> + int parity = 'n';
> + int flow = 'n';
> +
> + if ((co->index < 0) || (co->index >= MA35_UART_NR)) {
> + pr_debug("Console Port%x out of range\n", co->index);
> + return -EINVAL;
> + }
> +
> + np = ma35d1serial_uart_nodes[co->index];
> + p = &ma35d1serial_ports[co->index];
> + if (!np || !p)
> + return -ENODEV;
> +
> + if (of_property_read_u32_array(np, "reg", val32, ARRAY_SIZE(val32)) != 0)
> + return -EINVAL;
> +
> + p->port.iobase = val32[1];
> + p->port.membase = ioremap(p->port.iobase, MA35_UART_REG_SIZE);
> + if (!p->port.membase)
> + return -ENOMEM;
> +
> + p->port.ops = &ma35d1serial_ops;
> + p->port.line = 0;
> + p->port.uartclk = MA35_UART_CONSOLE_CLK;
> +
> + port = &ma35d1serial_ports[co->index].port;
> +
> + if (options)
> + uart_parse_options(options, &baud, &parity, &bits, &flow);
> +
> + return uart_set_options(port, co, baud, parity, bits, flow);
> +}
> +
> +static struct console ma35d1serial_console = {
> + .name = "ttyNVT",
> + .write = ma35d1serial_console_write,
> + .device = uart_console_device,
> + .setup = ma35d1serial_console_setup,
> + .flags = CON_PRINTBUFFER | CON_ENABLED,
> + .index = -1,
> + .data = &ma35d1serial_reg,
> +};
> +
> +static void ma35d1serial_console_init_port(void)
> +{
> + u32 i = 0;
> + struct device_node *np;
> +
> + for_each_matching_node(np, ma35d1_serial_of_match) {
> + if (ma35d1serial_uart_nodes[i] == NULL) {
> + of_node_get(np);
> + ma35d1serial_uart_nodes[i] = np;
> + i++;
> + if (i == MA35_UART_NR)
> + break;
> + }
> + }
> +}
> +
> +static int __init ma35d1serial_console_init(void)
> +{
> + ma35d1serial_console_init_port();
> + register_console(&ma35d1serial_console);
> + return 0;
> +}
> +console_initcall(ma35d1serial_console_init);
> +
> +#define MA35D1SERIAL_CONSOLE (&ma35d1serial_console)
> +#else
> +#define MA35D1SERIAL_CONSOLE NULL
> +#endif
> +
> +static struct uart_driver ma35d1serial_reg = {
> + .owner = THIS_MODULE,
> + .driver_name = "serial",
> + .dev_name = "ttyNVT",
> + .major = TTY_MAJOR,
> + .minor = 64,
> + .cons = MA35D1SERIAL_CONSOLE,
> + .nr = MA35_UART_NR,
> +};
> +
> +/*
> + * Register a set of serial devices attached to a platform device.
> + * The list is terminated with a zero flags entry, which means we expect
> + * all entries to have at least UPF_BOOT_AUTOCONF set.
> + */
> +static int ma35d1serial_probe(struct platform_device *pdev)
> +{
> + struct resource *res_mem;
> + struct uart_ma35d1_port *up;
> + int ret = 0;
> +
> + if (pdev->dev.of_node) {
> + ret = of_alias_get_id(pdev->dev.of_node, "serial");
> + if (ret < 0) {
> + dev_err(&pdev->dev, "failed to get alias/pdev id, errno %d\n", ret);
> + return ret;
> + }
> + }
> + up = &ma35d1serial_ports[ret];
> + up->port.line = ret;
> + res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res_mem)
> + return -ENODEV;
> +
> + up->port.iobase = res_mem->start;
> + up->port.membase = ioremap(up->port.iobase, MA35_UART_REG_SIZE);
> + up->port.ops = &ma35d1serial_ops;
> +
> + spin_lock_init(&up->port.lock);
> +
> + up->clk = of_clk_get(pdev->dev.of_node, 0);
> + if (IS_ERR(up->clk)) {
> + ret = PTR_ERR(up->clk);
> + dev_err(&pdev->dev, "failed to get core clk: %d\n", ret);
> + goto err_iounmap;
> + }
> +
> + ret = clk_prepare_enable(up->clk);
> + if (ret)
> + goto err_iounmap;
> +
> + if (up->port.line != 0)
> + up->port.uartclk = clk_get_rate(up->clk);
> +
> + ret = platform_get_irq(pdev, 0);
> + if (ret < 0)
> + goto err_clk_disable;
> +
> + up->port.irq = ret;
> + up->port.dev = &pdev->dev;
> + up->port.flags = UPF_BOOT_AUTOCONF;
> +
> + platform_set_drvdata(pdev, up);
> +
> + ret = uart_add_one_port(&ma35d1serial_reg, &up->port);
> + if (ret < 0)
> + goto err_free_irq;
> +
> + return 0;
> +
> +err_free_irq:
> + free_irq(up->port.irq, &up->port);
> +
> +err_clk_disable:
> + clk_disable_unprepare(up->clk);
> +
> +err_iounmap:
> + iounmap(up->port.membase);
> + return ret;
> +}
> +
> +/*
> + * Remove serial ports registered against a platform device.
> + */
> +static int ma35d1serial_remove(struct platform_device *dev)
> +{
> + struct uart_port *port = platform_get_drvdata(dev);
> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
> +
> + uart_remove_one_port(&ma35d1serial_reg, port);
> + clk_disable_unprepare(up->clk);
> + return 0;
> +}
> +
> +static int ma35d1serial_suspend(struct platform_device *dev, pm_message_t state)
> +{
> + struct uart_port *port = platform_get_drvdata(dev);
> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
> +
> + uart_suspend_port(&ma35d1serial_reg, &up->port);
> + if (up->port.line == 0) {
> + up->console_baud_rate = serial_in(up, MA35_BAUD_REG);
> + up->console_line = serial_in(up, MA35_LCR_REG);
> + up->console_int = serial_in(up, MA35_IER_REG);
> + }
> + return 0;
> +}
> +
> +static int ma35d1serial_resume(struct platform_device *dev)
> +{
> + struct uart_port *port = platform_get_drvdata(dev);
> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
> +
> + if (up->port.line == 0) {
> + serial_out(up, MA35_BAUD_REG, up->console_baud_rate);
> + serial_out(up, MA35_LCR_REG, up->console_line);
> + serial_out(up, MA35_IER_REG, up->console_int);
> + }
> + uart_resume_port(&ma35d1serial_reg, &up->port);
> + return 0;
> +}
> +
> +static struct platform_driver ma35d1serial_driver = {
> + .probe = ma35d1serial_probe,
> + .remove = ma35d1serial_remove,
> + .suspend = ma35d1serial_suspend,
> + .resume = ma35d1serial_resume,
> + .driver = {
> + .name = "ma35d1-uart",
> + .owner = THIS_MODULE,
> + .of_match_table = of_match_ptr(ma35d1_serial_of_match),
> + },
> +};
> +
> +static int __init ma35d1serial_init(void)
> +{
> + int ret;
> +
> + ret = uart_register_driver(&ma35d1serial_reg);
> + if (ret)
> + return ret;
> +
> + ret = platform_driver_register(&ma35d1serial_driver);
> + if (ret)
> + uart_unregister_driver(&ma35d1serial_reg);
> +
> + return ret;
> +}
> +
> +static void __exit ma35d1serial_exit(void)
> +{
> + platform_driver_unregister(&ma35d1serial_driver);
> + uart_unregister_driver(&ma35d1serial_reg);
> +}
> +
> +module_init(ma35d1serial_init);
> +module_exit(ma35d1serial_exit);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("MA35D1 serial driver");
> diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
> index 281fa286555c..c11600bb1b0d 100644
> --- a/include/uapi/linux/serial_core.h
> +++ b/include/uapi/linux/serial_core.h
> @@ -279,4 +279,7 @@
> /* Sunplus UART */
> #define PORT_SUNPLUS 123
>
> +/* Nuvoton MA35 SoC */
> +#define PORT_MA35 124
> +
> #endif /* _UAPILINUX_SERIAL_CORE_H */
>
Re: [PATCH v13 10/10] tty: serial: Add Nuvoton ma35d1 serial driver support [ In reply to ]
On 2023/6/6 ?? 04:19, Ilpo Järvinen wrote:
> On Mon, 5 Jun 2023, Jacky Huang wrote:
>
>> From: Jacky Huang <ychuang3@nuvoton.com>
>>
>> This adds UART and console driver for Nuvoton ma35d1 Soc.
>> It supports full-duplex communication, FIFO control, and
>> hardware flow control.
>>
>> Signed-off-by: Jacky Huang <ychuang3@nuvoton.com>
> A few stylistic things below, should be easy to address them I think. In
> general, this is in quite good shape already.
>
>> ---
>> drivers/tty/serial/Kconfig | 18 +
>> drivers/tty/serial/Makefile | 1 +
>> drivers/tty/serial/ma35d1_serial.c | 808 +++++++++++++++++++++++++++++
>> include/uapi/linux/serial_core.h | 3 +
>> 4 files changed, 830 insertions(+)
>> create mode 100644 drivers/tty/serial/ma35d1_serial.c
>>
>> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
>> index 3e3fb377d90d..71ea5138adce 100644
>> --- a/drivers/tty/serial/Kconfig
>> +++ b/drivers/tty/serial/Kconfig
>> @@ -1555,6 +1555,24 @@ config SERIAL_SUNPLUS_CONSOLE
>> you can alter that using a kernel command line option such as
>> "console=ttySUPx".
>>
>> +config SERIAL_NUVOTON_MA35D1
>> + tristate "Nuvoton MA35D1 family UART support"
>> + depends on ARCH_MA35 || COMPILE_TEST
>> + select SERIAL_CORE
>> + help
>> + This driver supports Nuvoton MA35D1 family UART ports. If you would
>> + like to use them, you must answer Y or M to this option. Note that
>> + for use as console, it must be included in kernel and not as a
>> + module
>> +
>> +config SERIAL_NUVOTON_MA35D1_CONSOLE
>> + bool "Console on a Nuvotn MA35D1 family UART port"
>> + depends on SERIAL_NUVOTON_MA35D1=y
>> + select SERIAL_CORE_CONSOLE
>> + help
>> + Select this options if you'd like to use the UART port0 of the
>> + Nuvoton MA35D1 family as a console.
>> +
>> endmenu
>>
>> config SERIAL_MCTRL_GPIO
>> diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
>> index cd9afd9e3018..0e823851c42c 100644
>> --- a/drivers/tty/serial/Makefile
>> +++ b/drivers/tty/serial/Makefile
>> @@ -93,3 +93,4 @@ obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o
>>
>> obj-$(CONFIG_SERIAL_KGDB_NMI) += kgdb_nmi.o
>> obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o
>> +obj-$(CONFIG_SERIAL_NUVOTON_MA35D1) += ma35d1_serial.o
>> diff --git a/drivers/tty/serial/ma35d1_serial.c b/drivers/tty/serial/ma35d1_serial.c
>> new file mode 100644
>> index 000000000000..6c19da7731a6
>> --- /dev/null
>> +++ b/drivers/tty/serial/ma35d1_serial.c
>> @@ -0,0 +1,808 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +/*
>> + * MA35D1 serial driver
>> + * Copyright (C) 2023 Nuvoton Technology Corp.
>> + */
>> +
>> +#include <linux/bitfield.h>
>> +#include <linux/clk.h>
>> +#include <linux/delay.h>
>> +#include <linux/of.h>
>> +#include <linux/of_platform.h>
>> +#include <linux/serial_core.h>
>> +#include <linux/slab.h>
>> +#include <linux/tty_flip.h>
>> +#include <linux/units.h>
>> +
>> +#define MA35_UART_NR 17
>> +
>> +#define MA35_RBR_REG 0x00
>> +#define MA35_THR_REG 0x00
>> +#define MA35_IER_REG 0x04
>> +#define MA35_FCR_REG 0x08
>> +#define MA35_LCR_REG 0x0C
>> +#define MA35_MCR_REG 0x10
>> +#define MA35_MSR_REG 0x14
>> +#define MA35_FSR_REG 0x18
>> +#define MA35_ISR_REG 0x1C
>> +#define MA35_TOR_REG 0x20
>> +#define MA35_BAUD_REG 0x24
>> +#define MA35_ALTCTL_REG 0x2C
>> +#define MA35_FUN_SEL_REG 0x30
>> +#define MA35_WKCTL_REG 0x40
>> +#define MA35_WKSTS_REG 0x44
>> +
>> +/* MA35_IER_REG - Interrupt Enable Register */
>> +#define MA35_IER_RDA_IEN BIT(0) /* RBR Available Interrupt Enable */
>> +#define MA35_IER_THRE_IEN BIT(1) /* THR Empty Interrupt Enable */
>> +#define MA35_IER_RLS_IEN BIT(2) /* RX Line Status Interrupt Enable */
>> +#define MA35_IER_RTO_IEN BIT(4) /* RX Time-out Interrupt Enable */
>> +#define MA35_IER_BUFERR_IEN BIT(5) /* Buffer Error Interrupt Enable */
>> +#define MA35_IER_TIME_OUT_EN BIT(11) /* RX Buffer Time-out Counter Enable */
>> +#define MA35_IER_AUTO_RTS BIT(12) /* nRTS Auto-flow Control Enable */
>> +#define MA35_IER_AUTO_CTS BIT(13) /* nCTS Auto-flow Control Enable */
>> +
>> +/* MA35_FCR_REG - FIFO Control Register */
>> +#define MA35_FCR_RFR BIT(1) /* RX Field Software Reset */
>> +#define MA35_FCR_TFR BIT(2) /* TX Field Software Reset */
>> +#define MA35_FCR_RFITL_MASK GENMASK(7, 4) /* RX FIFO Interrupt Trigger Level */
>> +#define MA35_FCR_RFITL_1BYTE FIELD_PREP(MA35_FCR_RFITL_MASK, 0)
>> +#define MA35_FCR_RFITL_4BYTES FIELD_PREP(MA35_FCR_RFITL_MASK, 1)
>> +#define MA35_FCR_RFITL_8BYTES FIELD_PREP(MA35_FCR_RFITL_MASK, 2)
>> +#define MA35_FCR_RFITL_14BYTES FIELD_PREP(MA35_FCR_RFITL_MASK, 3)
>> +#define MA35_FCR_RFITL_30BYTES FIELD_PREP(MA35_FCR_RFITL_MASK, 4)
>> +#define MA35_FCR_RTSTL_MASK GENMASK(19, 16) /* nRTS Trigger Level */
>> +#define MA35_FCR_RTSTL_1BYTE FIELD_PREP(MA35_FCR_RTSTL_MASK, 0)
>> +#define MA35_FCR_RTSTL_4BYTES FIELD_PREP(MA35_FCR_RTSTL_MASK, 1)
>> +#define MA35_FCR_RTSTL_8BYTES FIELD_PREP(MA35_FCR_RTSTL_MASK, 2)
>> +#define MA35_FCR_RTSTL_14BYTES FIELD_PREP(MA35_FCR_RTSTL_MASK, 3)
>> +#define MA35_FCR_RTSTLL_30BYTES FIELD_PREP(MA35_FCR_RTSTL_MASK, 4)
>> +
>> +/* MA35_LCR_REG - Line Control Register */
>> +#define MA35_LCR_NSB BIT(2) /* Number of “STOP Bit” */
>> +#define MA35_LCR_PBE BIT(3) /* Parity Bit Enable */
>> +#define MA35_LCR_EPE BIT(4) /* Even Parity Enable */
>> +#define MA35_LCR_SPE BIT(5) /* Stick Parity Enable */
>> +#define MA35_LCR_BREAK BIT(6) /* Break Control */
>> +#define MA35_LCR_WLS_MASK GENMASK(1, 0) /* Word Length Selection */
>> +#define MA35_LCR_WLS_5BITS FIELD_PREP(MA35_LCR_WLS_MASK, 0)
>> +#define MA35_LCR_WLS_6BITS FIELD_PREP(MA35_LCR_WLS_MASK, 1)
>> +#define MA35_LCR_WLS_7BITS FIELD_PREP(MA35_LCR_WLS_MASK, 2)
>> +#define MA35_LCR_WLS_8BITS FIELD_PREP(MA35_LCR_WLS_MASK, 3)
>> +
>> +/* MA35_MCR_REG - Modem Control Register */
>> +#define MA35_MCR_RTS_CTRL BIT(1) /* nRTS Signal Control */
>> +#define MA35_MCR_RTSACTLV BIT(9) /* nRTS Pin Active Level */
>> +#define MA35_MCR_RTSSTS BIT(13) /* nRTS Pin Status (Read Only) */
>> +
>> +/* MA35_MSR_REG - Modem Status Register */
>> +#define MA35_MSR_CTSDETF BIT(0) /* Detect nCTS State Change Flag */
>> +#define MA35_MSR_CTSSTS BIT(4) /* nCTS Pin Status (Read Only) */
>> +#define MA35_MSR_CTSACTLV BIT(8) /* nCTS Pin Active Level */
>> +
>> +/* MA35_FSR_REG - FIFO Status Register */
>> +#define MA35_FSR_RX_OVER_IF BIT(0) /* RX Overflow Error Interrupt Flag */
>> +#define MA35_FSR_PEF BIT(4) /* Parity Error Flag*/
>> +#define MA35_FSR_FEF BIT(5) /* Framing Error Flag */
>> +#define MA35_FSR_BIF BIT(6) /* Break Interrupt Flag */
>> +#define MA35_FSR_RX_EMPTY BIT(14) /* Receiver FIFO Empty (Read Only) */
>> +#define MA35_FSR_RX_FULL BIT(15) /* Receiver FIFO Full (Read Only) */
>> +#define MA35_FSR_TX_EMPTY BIT(22) /* Transmitter FIFO Empty (Read Only) */
>> +#define MA35_FSR_TX_FULL BIT(23) /* Transmitter FIFO Full (Read Only) */
>> +#define MA35_FSR_TX_OVER_IF BIT(24) /* TX Overflow Error Interrupt Flag */
>> +#define MA35_FSR_TE_FLAG BIT(28) /* Transmitter Empty Flag (Read Only) */
>> +#define MA35_FSR_RXPTR_MSK GENMASK(13, 8) /* TX FIFO Pointer mask */
>> +#define MA35_FSR_TXPTR_MSK GENMASK(21, 16) /* RX FIFO Pointer mask */
>> +
>> +/* MA35_ISR_REG - Interrupt Status Register */
>> +#define MA35_ISR_RDA_IF BIT(0) /* RBR Available Interrupt Flag */
>> +#define MA35_ISR_THRE_IF BIT(1) /* THR Empty Interrupt Flag */
>> +#define MA35_ISR_RLSIF BIT(2) /* Receive Line Interrupt Flag */
>> +#define MA35_ISR_MODEMIF BIT(3) /* MODEM Interrupt Flag */
>> +#define MA35_ISR_RXTO_IF BIT(4) /* RX Time-out Interrupt Flag */
>> +#define MA35_ISR_BUFEIF BIT(5) /* Buffer Error Interrupt Flag */
>> +#define MA35_ISR_WK_IF BIT(6) /* UART Wake-up Interrupt Flag */
>> +#define MA35_ISR_RDAINT BIT(8) /* RBR Available Interrupt Indicator */
>> +#define MA35_ISR_THRE_INT BIT(9) /* THR Empty Interrupt Indicator */
>> +#define MA35_ISR_ALL 0xFFFFFFFF
>> +
>> +/* MA35_BAUD_REG - Baud Rate Divider Register */
>> +#define MA35_BAUD_MODE_MASK GENMASK(29, 28)
>> +#define MA35_BAUD_MODE0 FIELD_PREP(MA35_BAUD_MODE_MASK, 0)
>> +#define MA35_BAUD_MODE1 FIELD_PREP(MA35_BAUD_MODE_MASK, 2)
>> +#define MA35_BAUD_MODE2 FIELD_PREP(MA35_BAUD_MODE_MASK, 3)
>> +#define MA35_BAUD_MASK GENMASK(15, 0)
>> +
>> +/* MA35_ALTCTL_REG - Alternate Control/Status Register */
>> +#define MA35_ALTCTL_RS485AUD BIT(10) /* RS-485 Auto Direction Function */
>> +
>> +/* MA35_FUN_SEL_REG - Function Select Register */
>> +#define MA35_FUN_SEL_MASK GENMASK(2, 0)
>> +#define MA35_FUN_SEL_UART FIELD_PREP(MA35_FUN_SEL_MASK, 0)
>> +#define MA35_FUN_SEL_RS485 FIELD_PREP(MA35_FUN_SEL_MASK, 3)
>> +
>> +/* The constrain for MA35D1 UART baud rate divider */
>> +#define MA35_BAUD_DIV_MAX 0xFFFF
>> +#define MA35_BAUD_DIV_MIN 11
>> +
>> +/* UART FIFO depth */
>> +#define MA35_UART_FIFO_DEPTH 32
>> +/* UART console clock */
>> +#define MA35_UART_CONSOLE_CLK (24 * HZ_PER_MHZ)
>> +/* UART register ioremap size */
>> +#define MA35_UART_REG_SIZE 0x100
>> +/* Rx Timeout */
>> +#define MA35_UART_RX_TOUT 0x40
>> +
>> +#define MA35_ISR_IF_CHECK (MA35_ISR_RDA_IF | MA35_ISR_RXTO_IF | \
>> + MA35_ISR_THRE_INT | MA35_ISR_BUFEIF)
>> +
>> +static struct uart_driver ma35d1serial_reg;
>> +
>> +struct uart_ma35d1_port {
>> + struct uart_port port;
>> + struct clk *clk;
>> + u16 capabilities; /* port capabilities */
>> + u8 ier;
>> + u8 lcr;
>> + u8 mcr;
>> + u32 baud_rate;
>> + u32 console_baud_rate;
>> + u32 console_line;
>> + u32 console_int;
>> +};
>> +
>> +static struct uart_ma35d1_port ma35d1serial_ports[MA35_UART_NR];
>> +
>> +static struct uart_ma35d1_port *to_ma35d1_uart_port(struct uart_port *uart)
>> +{
>> + return container_of(uart, struct uart_ma35d1_port, port);
>> +}
>> +
>> +static u32 serial_in(struct uart_ma35d1_port *p, u32 offset)
>> +{
>> + return readl_relaxed(p->port.membase + offset);
>> +}
>> +
>> +static void serial_out(struct uart_ma35d1_port *p, u32 offset, u32 value)
>> +{
>> + writel_relaxed(value, p->port.membase + offset);
>> +}
>> +
>> +static void __stop_tx(struct uart_ma35d1_port *p)
>> +{
>> + u32 ier;
>> +
>> + ier = serial_in(p, MA35_IER_REG);
>> + if (ier & MA35_IER_THRE_IEN)
>> + serial_out(p, MA35_IER_REG, ier & ~MA35_IER_THRE_IEN);
>> +}
>> +
>> +static void ma35d1serial_stop_tx(struct uart_port *port)
>> +{
>> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
>> +
>> + __stop_tx(up);
>> +}
>> +
>> +static void transmit_chars(struct uart_ma35d1_port *up)
>> +{
>> + u32 count;
>> + u8 ch;
>> +
>> + if (uart_tx_stopped(&up->port)) {
>> + ma35d1serial_stop_tx(&up->port);
>> + return;
>> + }
>> + count = MA35_UART_FIFO_DEPTH - FIELD_GET(MA35_FSR_TXPTR_MSK,
>> + serial_in(up, MA35_FSR_REG));
>> + uart_port_tx_limited(&up->port, ch, count,
>> + !(serial_in(up, MA35_FSR_REG) & MA35_FSR_TX_FULL),
>> + serial_out(up, MA35_THR_REG, ch),
>> + ({}));
>> +}
>> +
>> +static void ma35d1serial_start_tx(struct uart_port *port)
>> +{
>> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
>> + u32 ier;
>> +
>> + ier = serial_in(up, MA35_IER_REG);
>> + serial_out(up, MA35_IER_REG, ier & ~MA35_IER_THRE_IEN);
>> + transmit_chars(up);
>> + serial_out(up, MA35_IER_REG, ier | MA35_IER_THRE_IEN);
>> +}
>> +
>> +static void ma35d1serial_stop_rx(struct uart_port *port)
>> +{
>> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
>> +
>> + serial_out(up, MA35_IER_REG, serial_in(up, MA35_IER_REG) & ~MA35_IER_RDA_IEN);
> These should be split up to:
> reg = serial_in(...)
> reg &= ~MA35_IER_RDA_IEN;
> serial_out(...)
>
> There are other cases too besides this one, convert them all. It will help
> with some line splitting challenges too you seem to have below.
>
>> +}
>> +
>> +static void receive_chars(struct uart_ma35d1_port *up)
>> +{
>> + u8 ch, flag;
>> + u32 fsr;
>> + int max_count = 256;
>> +
>> + fsr = serial_in(up, MA35_FSR_REG);
>> + do {
>> + flag = TTY_NORMAL;
>> + up->port.icount.rx++;
>> +
>> + if (unlikely(fsr & (MA35_FSR_BIF | MA35_FSR_FEF |
>> + MA35_FSR_PEF | MA35_FSR_RX_OVER_IF))) {
>> + if (fsr & MA35_FSR_BIF) {
>> + up->port.icount.brk++;
>> + if (uart_handle_break(&up->port))
>> + continue;
>> + }
>> + if (fsr & MA35_FSR_FEF)
>> + up->port.icount.frame++;
>> + if (fsr & MA35_FSR_PEF)
>> + up->port.icount.parity++;
>> + if (fsr & MA35_FSR_RX_OVER_IF)
>> + up->port.icount.overrun++;
>> +
>> + serial_out(up, MA35_FSR_REG,
>> + fsr & (MA35_FSR_BIF | MA35_FSR_FEF |
>> + MA35_FSR_PEF | MA35_FSR_RX_OVER_IF));
>> + if (fsr & MA35_FSR_BIF)
>> + flag = TTY_BREAK;
>> + else if (fsr & MA35_FSR_PEF)
>> + flag = TTY_PARITY;
>> + else if (fsr & MA35_FSR_FEF)
>> + flag = TTY_FRAME;
>> + }
>> +
>> + ch = serial_in(up, MA35_RBR_REG);
>> + if (uart_handle_sysrq_char(&up->port, ch))
>> + continue;
>> +
>> + spin_lock(&up->port.lock);
>> + uart_insert_char(&up->port, fsr, MA35_FSR_RX_OVER_IF, ch, flag);
>> + spin_unlock(&up->port.lock);
>> +
>> + fsr = serial_in(up, MA35_FSR_REG);
>> + } while (!(fsr & MA35_FSR_RX_EMPTY) && (max_count-- > 0));
>> +
>> + spin_lock(&up->port.lock);
>> + tty_flip_buffer_push(&up->port.state->port);
>> + spin_unlock(&up->port.lock);
>> +}
>> +
>> +static irqreturn_t ma35d1serial_interrupt(int irq, void *dev_id)
>> +{
>> + struct uart_port *port = dev_id;
>> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
>> + u32 isr, fsr;
>> +
>> + isr = serial_in(up, MA35_ISR_REG);
>> + fsr = serial_in(up, MA35_FSR_REG);
>> +
>> + if (!(isr & MA35_ISR_IF_CHECK))
>> + return IRQ_NONE;
>> +
>> + if (isr & (MA35_ISR_RDA_IF | MA35_ISR_RXTO_IF))
>> + receive_chars(up);
>> + if (isr & MA35_ISR_THRE_INT)
>> + transmit_chars(up);
>> + if (fsr & MA35_FSR_TX_OVER_IF)
>> + serial_out(up, MA35_FSR_REG, MA35_FSR_TX_OVER_IF);
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> +static u32 ma35d1serial_tx_empty(struct uart_port *port)
>> +{
>> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
>> + u32 fsr;
>> +
>> + fsr = serial_in(up, MA35_FSR_REG);
>> + return (fsr & (MA35_FSR_TE_FLAG | MA35_FSR_TX_EMPTY)) ==
>> + (MA35_FSR_TE_FLAG | MA35_FSR_TX_EMPTY) ? TIOCSER_TEMT : 0;
> To make this check cleaner, add this and use it here:
>
> #define MA35_FSR_TX_BOTH_EMPTY (MA35_FSR_TE_FLAG | MA35_FSR_TX_EMPTY)
>
>> +}
>> +
>> +static u32 ma35d1serial_get_mctrl(struct uart_port *port)
>> +{
>> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
>> + u32 status;
>> + u32 ret = 0;
>> +
>> + status = serial_in(up, MA35_MSR_REG);
>> + if (!(status & MA35_MSR_CTSSTS))
>> + ret |= TIOCM_CTS;
>> + return ret;
>> +}
>> +
>> +static void ma35d1serial_set_mctrl(struct uart_port *port, u32 mctrl)
>> +{
>> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
>> + u32 mcr;
>> + u32 ier;
>> +
>> + mcr = serial_in(up, MA35_MCR_REG);
>> + mcr &= ~MA35_MCR_RTS_CTRL;
>> +
>> + if (mctrl & TIOCM_RTS)
>> + mcr |= MA35_MCR_RTSACTLV;
>> + else
>> + mcr &= ~MA35_MCR_RTSACTLV;
>> +
>> + if (up->mcr & UART_MCR_AFE) {
>> + serial_out(up, MA35_IER_REG, (serial_in(up, MA35_IER_REG) |
>> + MA35_IER_AUTO_RTS |
>> + MA35_IER_AUTO_CTS));
>> + up->port.flags |= UPF_HARD_FLOW;
>> + } else {
>> + ier = serial_in(up, MA35_IER_REG);
>> + ier &= ~(MA35_IER_AUTO_RTS | MA35_IER_AUTO_CTS);
>> + serial_out(up, MA35_IER_REG, ier);
>> + up->port.flags &= ~UPF_HARD_FLOW;
>> + }
>> + serial_out(up, MA35_MSR_REG, (serial_in(up, MA35_MSR_REG) |
>> + MA35_MSR_CTSACTLV));
>> + serial_out(up, MA35_MCR_REG, mcr);
>> +}
>> +
>> +static void ma35d1serial_break_ctl(struct uart_port *port, int break_state)
>> +{
>> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
>> + unsigned long flags;
>> + u32 lcr;
>> +
>> + spin_lock_irqsave(&up->port.lock, flags);
>> + lcr = serial_in(up, MA35_LCR_REG);
>> + if (break_state != 0)
>> + lcr |= MA35_LCR_BREAK;
>> + else
>> + lcr &= ~MA35_LCR_BREAK;
>> + serial_out(up, MA35_LCR_REG, lcr);
>> + spin_unlock_irqrestore(&up->port.lock, flags);
>> +}
>> +
>> +static int ma35d1serial_startup(struct uart_port *port)
>> +{
>> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
>> + int retval;
>> +
>> + /* Reset FIFO */
>> + serial_out(up, MA35_FCR_REG, MA35_FCR_TFR | MA35_FCR_RFR);
>> +
>> + /* Clear pending interrupts */
>> + serial_out(up, MA35_ISR_REG, MA35_ISR_ALL);
>> +
>> + retval = request_irq(port->irq, ma35d1serial_interrupt, 0,
>> + dev_name(port->dev), port);
>> + if (retval) {
>> + dev_err(up->port.dev, "request irq failed.\n");
>> + return retval;
>> + }
>> +
>> + serial_out(up, MA35_FCR_REG, serial_in(up, MA35_FCR_REG) |
>> + MA35_FCR_RFITL_4BYTES | MA35_FCR_RTSTL_8BYTES);
>> + serial_out(up, MA35_LCR_REG, MA35_LCR_WLS_8BITS);
>> + serial_out(up, MA35_TOR_REG, MA35_UART_RX_TOUT);
>> + serial_out(up, MA35_IER_REG, MA35_IER_RTO_IEN | MA35_IER_RDA_IEN |
>> + MA35_IER_TIME_OUT_EN | MA35_IER_BUFERR_IEN);
> Align to the parameter like this:
> serial_out(up, MA35_IER_REG, MA35_IER_RTO_IEN | MA35_IER_RDA_IEN |
> MA35_IER_TIME_OUT_EN | MA35_IER_BUFERR_IEN);
>
>
>> + return 0;
>> +}
>> +
>> +static void ma35d1serial_shutdown(struct uart_port *port)
>> +{
>> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
>> +
>> + serial_out(up, MA35_IER_REG, 0);
>> + free_irq(port->irq, port);
>> +}
>> +
>> +static void ma35d1serial_set_termios(struct uart_port *port,
>> + struct ktermios *termios,
>> + const struct ktermios *old)
>> +{
>> + struct uart_ma35d1_port *up = to_ma35d1_uart_port(port);
>> + u32 lcr = 0;
>> + unsigned long flags;
>> + u32 baud, quot;
>> +
>> + lcr = UART_LCR_WLEN(tty_get_char_size(termios->c_cflag));
>> +
>> + if (termios->c_cflag & CSTOPB)
>> + lcr |= MA35_LCR_NSB;
>> + if (termios->c_cflag & PARENB)
>> + lcr |= MA35_LCR_PBE;
>> + if (!(termios->c_cflag & PARODD))
>> + lcr |= MA35_LCR_EPE;
>> + if (termios->c_cflag & CMSPAR)
>> + lcr |= MA35_LCR_SPE;
>> +
>> + baud = uart_get_baud_rate(port, termios, old,
>> + port->uartclk / MA35_BAUD_DIV_MAX,
>> + port->uartclk / MA35_BAUD_DIV_MIN);
>> +
>> + /* MA35D1 UART baud rate equation: baudrate = UART_CLK / (quot + 2) */
>> + quot = (port->uartclk / baud) - 2;
>> +
>> + /*
>> + * Ok, we're now changing the port state. Do it with
>> + * interrupts disabled.
>> + */
>> + spin_lock_irqsave(&up->port.lock, flags);
>> +
>> + up->port.read_status_mask = MA35_FSR_RX_OVER_IF;
>> + if (termios->c_iflag & INPCK)
>> + up->port.read_status_mask |= MA35_FSR_FEF | MA35_FSR_PEF;
>> + if (termios->c_iflag & (BRKINT | PARMRK))
>> + up->port.read_status_mask |= MA35_FSR_BIF;
>> +
>> + /* Characteres to ignore */
>> + up->port.ignore_status_mask = 0;
>> + if (termios->c_iflag & IGNPAR)
>> + up->port.ignore_status_mask |= MA35_FSR_FEF | MA35_FSR_PEF;
>> + if (termios->c_iflag & IGNBRK) {
>> + up->port.ignore_status_mask |= MA35_FSR_BIF;
>> + /*
>> + * If we're ignoring parity and break indicators,
>> + * ignore overruns too (for real raw support).
>> + */
>> + if (termios->c_iflag & IGNPAR)
>> + up->port.ignore_status_mask |= MA35_FSR_RX_OVER_IF;
>> + }
>> + if (termios->c_cflag & CRTSCTS)
>> + up->mcr |= UART_MCR_AFE;
>> + else
>> + up->mcr &= ~UART_MCR_AFE;
>> +
>> + uart_update_timeout(port, termios->c_cflag, baud);
>> +
>> + ma35d1serial_set_mctrl(&up->port, up->port.mctrl);
>> +
>> + serial_out(up, MA35_BAUD_REG, MA35_BAUD_MODE2 | FIELD_PREP(MA35_BAUD_MASK, quot));
>> +
>> + serial_out(up, MA35_LCR_REG, lcr);
>> +
>> + spin_unlock_irqrestore(&up->port.lock, flags);
>> +}
>> +
>> +static const char *ma35d1serial_type(struct uart_port *port)
>> +{
>> + return port->type == PORT_MA35 ? "ma35d1-uart" : NULL;
>> +}
>> +
>> +static void ma35d1serial_config_port(struct uart_port *port, int flags)
>> +{
>> + if (flags & UART_CONFIG_TYPE)
>> + port->type = PORT_MA35;
>> +}
>> +
>> +static int ma35d1serial_verify_port(struct uart_port *port, struct serial_struct *ser)
>> +{
>> + if (port->type != PORT_UNKNOWN && ser->type != PORT_MA35)
>> + return -EINVAL;
>> +
>> + return 0;
>> +}
>> +
>> +static const struct uart_ops ma35d1serial_ops = {
>> + .tx_empty = ma35d1serial_tx_empty,
>> + .set_mctrl = ma35d1serial_set_mctrl,
>> + .get_mctrl = ma35d1serial_get_mctrl,
>> + .stop_tx = ma35d1serial_stop_tx,
>> + .start_tx = ma35d1serial_start_tx,
>> + .stop_rx = ma35d1serial_stop_rx,
>> + .break_ctl = ma35d1serial_break_ctl,
>> + .startup = ma35d1serial_startup,
>> + .shutdown = ma35d1serial_shutdown,
>> + .set_termios = ma35d1serial_set_termios,
>> + .type = ma35d1serial_type,
>> + .config_port = ma35d1serial_config_port,
>> + .verify_port = ma35d1serial_verify_port,
>> +};
>> +
>> +static const struct of_device_id ma35d1_serial_of_match[] = {
>> + { .compatible = "nuvoton,ma35d1-uart" },
>> + {},
>> +};
>> +MODULE_DEVICE_TABLE(of, ma35d1_serial_of_match);
>> +
>> +#ifdef CONFIG_SERIAL_NUVOTON_MA35D1_CONSOLE
>> +
>> +static struct device_node *ma35d1serial_uart_nodes[MA35_UART_NR];
>> +
>> +static void wait_for_xmitr(struct uart_ma35d1_port *up)
>> +{
>> + unsigned int tmout;
>> +
>> + /* Wait up to 10ms for the character(s) to be sent. */
>> + tmout = 10000;
>> + while (--tmout) {
>> + if (serial_in(up, MA35_FSR_REG) & MA35_FSR_TX_EMPTY)
>> + break;
>> + udelay(1);
>> + }
> This can be written as:
>
> unsigned int reg;
>
> read_poll_timeout_atomic(serial_in, reg, reg & MA35_FSR_TX_EMPTY,
> 1, 10000, false,
> up, MA35_FSR_REG);
>
>

Dear Ilpo,

Thank you for your suggestions and the provided examples for modifications.
I will modify the driver based on your suggestions. After a few days, if no
further comments are received, I will submit the next version of this
one patch.


Best Regards.
Jacky Huang