Re: [PATCH v12 10/10] tty: serial: Add Nuvoton ma35d1 serial driver support
From: Ilpo Järvinen
Date: Tue May 30 2023 - 04:33:20 EST
On Tue, 30 May 2023, Jacky Huang wrote:
> From: Jacky Huang <ychuang3@xxxxxxxxxxx>
>
> 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@xxxxxxxxxxx>
> ---
> drivers/tty/serial/Kconfig | 18 +
> drivers/tty/serial/Makefile | 1 +
> drivers/tty/serial/ma35d1_serial.c | 801 +++++++++++++++++++++++++++++
> include/uapi/linux/serial_core.h | 3 +
> 4 files changed, 823 insertions(+)
> create mode 100644 drivers/tty/serial/ma35d1_serial.c
>
> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
> index 398e5aac2e77..85ac6fc1ff1d 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..c0a8c1e4ca0e
> --- /dev/null
> +++ b/drivers/tty/serial/ma35d1_serial.c
> @@ -0,0 +1,801 @@
> +// 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;
> + u32 ier;
> +
> + spin_lock_irqsave(&up->port.lock, flags);
This lacks the oops_in_progress trickery the other drivers do?
Although I think there really should be uart_console_write_lock(uart_port
*up, unsigned long *flags, bool *locked) and uart_console_write_unlock()
helpers in serial core for this task.
--
i.
> + /*
> + * 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);
> +
> + 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 */
>