[PATCH v10 10/10] tty: serial: Add Nuvoton ma35d1 serial driver support

Jacky Huang
2023-05-08T03:02:14Z

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 | 796 +++++++++++++++++++++++++++++
3 files changed, 815 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..4eca34ba01c9
--- /dev/null
+++ b/drivers/tty/serial/ma35d1_serial.c
@@ -0,0 +1,796 @@
+// 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>
+
+#define UART_NR 17
+
+#define UART_REG_RBR 0x00
+#define UART_REG_THR 0x00
+#define UART_REG_IER 0x04
+#define UART_REG_FCR 0x08
+#define UART_REG_LCR 0x0C
+#define UART_REG_MCR 0x10
+#define UART_REG_MSR 0x14
+#define UART_REG_FSR 0x18
+#define UART_REG_ISR 0x1C
+#define UART_REG_TOR 0x20
+#define UART_REG_BAUD 0x24
+#define UART_REG_ALTCTL 0x2C
+#define UART_FUN_SEL 0x30
+#define UART_REG_WKCTL 0x40
+#define UART_REG_WKSTS 0x44
+
+/* UART_REG_IER - Interrupt Enable Register */
+#define IER_RDA_IEN BIT(0) /* RBR Available Interrupt Enable */
+#define IER_THRE_IEN BIT(1) /* THR Empty Interrupt Enable */
+#define IER_RLS_IEN BIT(2) /* RX Line Status Interrupt Enable */
+#define IER_RTO_IEN BIT(4) /* RX Time-out Interrupt Enable */
+#define IER_BUFERR_IEN BIT(5) /* Buffer Error Interrupt Enable */
+#define IER_TIME_OUT_EN BIT(11) /* RX Buffer Time-out Counter Enable */
+#define IER_AUTO_RTS BIT(12) /* nRTS Auto-flow Control Enable */
+#define IER_AUTO_CTS BIT(13) /* nCTS Auto-flow Control Enable */
+
+/* UART_REG_FCR - FIFO Control Register */
+#define FCR_RFR BIT(1) /* RX Field Software Reset */
+#define FCR_TFR BIT(2) /* TX Field Software Reset */
+#define FCR_RFITL_MASK GENMASK(7, 4) /* RX FIFO Interrupt Trigger Level */
+#define FCR_RFITL_1BYTE FIELD_PREP(FCR_RFITL_MASK, 0)
+#define FCR_RFITL_4BYTES FIELD_PREP(FCR_RFITL_MASK, 1)
+#define FCR_RFITL_8BYTES FIELD_PREP(FCR_RFITL_MASK, 2)
+#define FCR_RFITL_14BYTES FIELD_PREP(FCR_RFITL_MASK, 3)
+#define FCR_RFITL_30BYTES FIELD_PREP(FCR_RFITL_MASK, 4)
+#define FCR_RTSTRGLV_MASK GENMASK(19, 16) /* nRTS Trigger Level */
+#define FCR_RTSTRGLV_1BYTE FIELD_PREP(FCR_RTSTRGLV_MASK, 0)
+#define FCR_RTSTRGLV_4BYTES FIELD_PREP(FCR_RTSTRGLV_MASK, 1)
+#define FCR_RTSTRGLV_8BYTES FIELD_PREP(FCR_RTSTRGLV_MASK, 2)
+#define FCR_RTSTRGLV_14BYTES FIELD_PREP(FCR_RTSTRGLV_MASK, 3)
+#define FCR_RTSTRGLVL_30BYTES FIELD_PREP(FCR_RTSTRGLV_MASK, 4)
+
+/* UART_REG_LCR - Line Control Register */
+#define LCR_NSB BIT(2) /* Number of “STOP Bit” */
+#define LCR_PBE BIT(3) /* Parity Bit Enable */
+#define LCR_EPE BIT(4) /* Even Parity Enable */
+#define LCR_SPE BIT(5) /* Stick Parity Enable */
+#define LCR_BREAK BIT(6) /* Break Control */
+#define LCR_WLS_MASK GENMASK(1, 0) /* Word Length Selection */
+#define LCR_WLS_5BITS FIELD_PREP(LCR_WLS_MASK, 0)
+#define LCR_WLS_6BITS FIELD_PREP(LCR_WLS_MASK, 1)
+#define LCR_WLS_7BITS FIELD_PREP(LCR_WLS_MASK, 2)
+#define LCR_WLS_8BITS FIELD_PREP(LCR_WLS_MASK, 3)
+
+/* UART_REG_MCR - Modem Control Register */
+#define MCR_RTS_CTRL BIT(1) /* nRTS Signal Control */
+#define MCR_RTSACTLV BIT(9) /* nRTS Pin Active Level */
+#define MCR_RTSSTS BIT(13) /* nRTS Pin Status (Read Only) */
+
+/* UART_REG_MSR - Modem Status Register */
+#define MSR_CTSDETF BIT(0) /* Detect nCTS State Change Flag */
+#define MSR_CTSSTS BIT(4) /* nCTS Pin Status (Read Only) */
+#define MSR_CTSACTLV BIT(8) /* nCTS Pin Active Level */
+
+/* UART_REG_FSR - FIFO Status Register */
+#define FSR_RX_OVER_IF BIT(0) /* RX Overflow Error Interrupt Flag */
+#define FSR_PEF BIT(4) /* Parity Error Flag*/
+#define FSR_FEF BIT(5) /* Framing Error Flag */
+#define FSR_BIF BIT(6) /* Break Interrupt Flag */
+#define FSR_RX_EMPTY BIT(14) /* Receiver FIFO Empty (Read Only) */
+#define FSR_RX_FULL BIT(15) /* Receiver FIFO Full (Read Only) */
+#define FSR_TX_EMPTY BIT(22) /* Transmitter FIFO Empty (Read Only) */
+#define FSR_TX_FULL BIT(23) /* Transmitter FIFO Full (Read Only) */
+#define FSR_TX_OVER_IF BIT(24) /* TX Overflow Error Interrupt Flag */
+#define FSR_TE_FLAG BIT(28) /* Transmitter Empty Flag (Read Only) */
+#define FSR_RXPTR_MSK GENMASK(13, 8) /* TX FIFO Pointer mask */
+#define FSR_TXPTR_MSK GENMASK(21, 16) /* RX FIFO Pointer mask */
+
+/* UART_REG_ISR - Interrupt Status Register */
+#define ISR_RDA_IF BIT(0) /* RBR Available Interrupt Flag */
+#define ISR_THRE_IF BIT(1) /* THR Empty Interrupt Flag */
+#define ISR_RLSIF BIT(2) /* Receive Line Interrupt Flag */
+#define ISR_MODEMIF BIT(3) /* MODEM Interrupt Flag */
+#define ISR_RXTO_IF BIT(4) /* RX Time-out Interrupt Flag */
+#define ISR_BUFEIF BIT(5) /* Buffer Error Interrupt Flag */
+#define UART_ISR_WK_IF BIT(6) /* UART Wake-up Interrupt Flag */
+#define UART_ISR_RDAINT BIT(8) /* RBR Available Interrupt Indicator */
+#define ISR_THRE_INT BIT(9) /* THR Empty Interrupt Indicator */
+#define ISR_ALL 0xFFFFFFFF
+
+/* UART_REG_BAUD - Baud Rate Divider Register */
+#define BAUD_MODE_MASK GENMASK(29, 28)
+#define BAUD_MODE0 FIELD_PREP(BAUD_MODE_MASK, 0)
+#define BAUD_MODE1 FIELD_PREP(BAUD_MODE_MASK, 2)
+#define BAUD_MODE2 FIELD_PREP(BAUD_MODE_MASK, 3)
+
+/* UART_REG_ALTCTL - Alternate Control/Status Register */
+#define ALTCTL_RS485AUD BIT(10) /* RS-485 Auto Direction Function */
+
+/* UART_FUN_SEL - Function Select Register */
+#define FUN_SEL_MASK GENMASK(2, 0)
+#define FUN_SEL_UART FIELD_PREP(FUN_SEL_MASK, 0)
+#define FUN_SEL_RS485 FIELD_PREP(FUN_SEL_MASK, 3)
+
+/* UART FIFO depth */
+#define UART_FIFO_DEPTH 32
+/* UART console clock */
+#define UART_CONSOLE_CLK 24000000
+/* UART register ioremap size */
+#define UART_REG_SIZE 0x100
+/* Rx Timeout */
+#define UART_RX_TOUT 0x40
+
+#define UART_ISR_IF_CHECK (ISR_RDA_IF | ISR_RXTO_IF | ISR_THRE_INT | ISR_BUFEIF)
+
+#define LOOP_TIMEOUT 1000
+
+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[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, UART_REG_IER);
+ if (ier & IER_THRE_IEN)
+ serial_out(p, UART_REG_IER, ier & ~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 = UART_FIFO_DEPTH - FIELD_GET(FSR_TXPTR_MSK, serial_in(up, UART_REG_FSR));
+ uart_port_tx_limited(&up->port, ch, count,
+ !(serial_in(up, UART_REG_FSR) & FSR_TX_FULL),
+ serial_out(up, UART_REG_THR, 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, UART_REG_IER);
+ serial_out(up, UART_REG_IER, ier & ~IER_THRE_IEN);
+ transmit_chars(up);
+ serial_out(up, UART_REG_IER, ier | 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, UART_REG_IER, serial_in(up, UART_REG_IER) & ~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, UART_REG_FSR);
+ do {
+ flag = TTY_NORMAL;
+ up->port.icount.rx++;
+
+ if (unlikely(fsr & (FSR_BIF | FSR_FEF | FSR_PEF | FSR_RX_OVER_IF))) {
+ if (fsr & FSR_BIF) {
+ up->port.icount.brk++;
+ if (uart_handle_break(&up->port))
+ continue;
+ }
+ if (fsr & FSR_FEF)
+ up->port.icount.frame++;
+ if (fsr & FSR_PEF)
+ up->port.icount.parity++;
+ if (fsr & FSR_RX_OVER_IF)
+ up->port.icount.overrun++;
+
+ serial_out(up, UART_REG_FSR, fsr &
+ (FSR_BIF | FSR_FEF | FSR_PEF | FSR_RX_OVER_IF));
+
+ if (fsr & FSR_BIF)
+ flag = TTY_BREAK;
+ else if (fsr & FSR_PEF)
+ flag = TTY_PARITY;
+ else if (fsr & FSR_FEF)
+ flag = TTY_FRAME;
+ }
+
+ ch = serial_in(up, UART_REG_RBR);
+ if (uart_handle_sysrq_char(&up->port, ch))
+ continue;
+
+ spin_lock(&up->port.lock);
+ uart_insert_char(&up->port, fsr, FSR_RX_OVER_IF, ch, flag);
+ spin_unlock(&up->port.lock);
+
+ fsr = serial_in(up, UART_REG_FSR);
+ } while (!(fsr & 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, UART_REG_ISR);
+ fsr = serial_in(up, UART_REG_FSR);
+
+ if (!(isr & UART_ISR_IF_CHECK))
+ return IRQ_NONE;
+
+ if (isr & (ISR_RDA_IF | ISR_RXTO_IF))
+ receive_chars(up);
+ if (isr & ISR_THRE_INT)
+ transmit_chars(up);
+ if (fsr & FSR_TX_OVER_IF)
+ serial_out(up, UART_REG_FSR, 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, UART_REG_FSR);
+ return (fsr & (FSR_TE_FLAG | FSR_TX_EMPTY)) ==
+ (FSR_TE_FLAG | 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, UART_REG_MSR);
+ if (!(status & 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 = 0;
+ u32 ier = 0;
+
+ if (mctrl & TIOCM_RTS) {
+ mcr = serial_in(up, UART_REG_MCR);
+ mcr |= MCR_RTSACTLV;
+ mcr &= ~MCR_RTS_CTRL;
+ }
+ if (up->mcr & UART_MCR_AFE) {
+ mcr = serial_in(up, UART_REG_MCR);
+ mcr |= MCR_RTSACTLV;
+ mcr &= ~MCR_RTS_CTRL;
+
+ serial_out(up, UART_REG_IER,
+ (serial_in(up, UART_REG_IER) | IER_AUTO_RTS | IER_AUTO_CTS));
+
+ up->port.flags |= UPF_HARD_FLOW;
+ } else {
+ ier = serial_in(up, UART_REG_IER);
+ ier &= ~(IER_AUTO_RTS | IER_AUTO_CTS);
+ serial_out(up, UART_REG_IER, ier);
+
+ up->port.flags &= ~UPF_HARD_FLOW;
+ }
+ serial_out(up, UART_REG_MSR, (serial_in(up, UART_REG_MSR) | MSR_CTSACTLV));
+ serial_out(up, UART_REG_MCR, 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, UART_REG_LCR);
+ if (break_state != 0)
+ lcr |= LCR_BREAK;
+ else
+ lcr &= ~LCR_BREAK;
+ serial_out(up, UART_REG_LCR, 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, UART_REG_FCR, FCR_TFR | FCR_RFR);
+
+ /* Clear pending interrupts */
+ serial_out(up, UART_REG_ISR, 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, UART_REG_FCR, serial_in(up, UART_REG_FCR) |
+ FCR_RFITL_4BYTES | FCR_RTSTRGLV_8BYTES);
+ serial_out(up, UART_REG_LCR, LCR_WLS_8BITS);
+ serial_out(up, UART_REG_TOR, UART_RX_TOUT);
+ serial_out(up, UART_REG_IER, IER_RTO_IEN | IER_RDA_IEN |
+ IER_TIME_OUT_EN | 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, UART_REG_IER, 0);
+ free_irq(port->irq, port);
+}
+
+static u32 ma35d1serial_get_divisor(struct uart_port *port, u32 baud)
+{
+ return (port->uartclk / baud) - 2;
+}
+
+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 |= LCR_NSB;
+ if (termios->c_cflag & PARENB)
+ lcr |= LCR_PBE;
+ if (!(termios->c_cflag & PARODD))
+ lcr |= LCR_EPE;
+ if (termios->c_cflag & CMSPAR)
+ lcr |= LCR_SPE;
+
+ baud = uart_get_baud_rate(port, termios, old, port->uartclk / 0xffff,
+ port->uartclk / 11);
+
+ quot = ma35d1serial_get_divisor(port, baud);
+
+ /*
+ * 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 = FSR_RX_OVER_IF;
+ if (termios->c_iflag & INPCK)
+ up->port.read_status_mask |= FSR_FEF | FSR_PEF;
+ if (termios->c_iflag & (BRKINT | PARMRK))
+ up->port.read_status_mask |= FSR_BIF;
+
+ /* Characteres to ignore */
+ up->port.ignore_status_mask = 0;
+ if (termios->c_iflag & IGNPAR)
+ up->port.ignore_status_mask |= FSR_FEF | FSR_PEF;
+ if (termios->c_iflag & IGNBRK) {
+ up->port.ignore_status_mask |= 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 |= 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, UART_REG_BAUD, quot | BAUD_MODE2);
+ serial_out(up, UART_REG_LCR, lcr);
+ spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static const char *ma35d1serial_type(struct uart_port *port)
+{
+ return "ma35d1-uart";
+}
+
+static void ma35d1serial_config_port(struct uart_port *port, int flags)
+{
+ /*
+ * Driver core for serial ports forces a non-zero value for port type.
+ * Write an arbitrary value here to accommodate the serial core driver,
+ * as ID part of UAPI is redundant.
+ */
+ port->type = 1;
+}
+
+static int ma35d1serial_verify_port(struct uart_port *port,
+ struct serial_struct *ser)
+{
+ if (port->type != PORT_UNKNOWN && ser->type != 1)
+ 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[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, UART_REG_FSR) & 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, UART_REG_THR, 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);
+
+ /*
+ * First save the IER then disable the interrupts
+ */
+ ier = serial_in(up, UART_REG_IER);
+ serial_out(up, UART_REG_IER, 0);
+
+ uart_console_write(&up->port, s, count, ma35d1serial_console_putchar);
+
+ wait_for_xmitr(up);
+ serial_out(up, UART_REG_IER, ier);
+
+ spin_unlock_irqrestore(&up->port.lock, flags);
+}
+
+static int __init ma35d1serial_console_setup(struct console *co,
+ char *options)
+{
+ struct device_node *np = ma35d1serial_uart_nodes[co->index];
+ struct uart_ma35d1_port *p = &ma35d1serial_ports[co->index];
+ u32 val32[4];
+ struct uart_port *port;
+ int baud = 115200;
+ int bits = 8;
+ int parity = 'n';
+ int flow = 'n';
+
+ /*
+ * Check whether an invalid uart number has been specified, and
+ * if so, search for the first available port that does have
+ * console support.
+ */
+ if ((co->index < 0) || (co->index >= UART_NR)) {
+ pr_debug("Console Port%x out of range\n", co->index);
+ return -EINVAL;
+ }
+
+ if (of_property_read_u32_array(np, "reg", val32, 4) != 0)
+ return -EINVAL;
+ p->port.iobase = val32[1];
+ p->port.membase = ioremap(p->port.iobase, UART_REG_SIZE);
+ p->port.ops = &ma35d1serial_ops;
+ p->port.line = 0;
+ p->port.uartclk = 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 = "ttyS",
+ .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 == 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 = "ttyS",
+ .major = TTY_MAJOR,
+ .minor = 64,
+ .cons = MA35D1SERIAL_CONSOLE,
+ .nr = 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, 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, UART_REG_BAUD);
+ up->console_line = serial_in(up, UART_REG_LCR);
+ up->console_int = serial_in(up, UART_REG_IER);
+ }
+ 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, UART_REG_BAUD, up->console_baud_rate);
+ serial_out(up, UART_REG_LCR, up->console_line);
+ serial_out(up, UART_REG_IER, 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");
+
--
2.34.1