[PATCH v7 10/11] tty: serial: Add RDA8810PL UART driver

Manivannan Sadhasivam
2018-12-18T15:04:25Z

Add UART driver for RDA Micro RDA8810PL SoC.

Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
---
.../admin-guide/kernel-parameters.txt | 6 +
drivers/tty/serial/Kconfig | 19 +
drivers/tty/serial/Makefile | 1 +
drivers/tty/serial/rda-uart.c | 831 ++++++++++++++++++
include/uapi/linux/serial_core.h | 3 +
5 files changed, 860 insertions(+)
create mode 100644 drivers/tty/serial/rda-uart.c

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index aefd358a5ca3..98ee9eaa52be 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1021,6 +1021,12 @@
specified address. The serial port must already be
setup and configured. Options are not yet supported.

+ rda,<addr>
+ Start an early, polled-mode console on a serial port
+ of an RDA Micro SoC, such as RDA8810PL, at the
+ specified address. The serial port must already be
+ setup and configured. Options are not yet supported.
+
smh Use ARM semihosting calls for early console.

s3c2410,<addr>
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 32886c304641..67b9bf3b500e 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1529,6 +1529,25 @@ config SERIAL_OWL_CONSOLE
Say 'Y' here if you wish to use Actions Semiconductor S500/S900 UART
as the system console.

+config SERIAL_RDA
+ bool "RDA Micro serial port support"
+ depends on ARCH_RDA || COMPILE_TEST
+ select SERIAL_CORE
+ help
+ This driver is for RDA8810PL SoC's UART.
+ Say 'Y' here if you wish to use the on-board serial port.
+ Otherwise, say 'N'.
+
+config SERIAL_RDA_CONSOLE
+ bool "Console on RDA Micro serial port"
+ depends on SERIAL_RDA=y
+ select SERIAL_CORE_CONSOLE
+ select SERIAL_EARLYCON
+ default y
+ help
+ Say 'Y' here if you wish to use the RDA8810PL UART as the system
+ console. Only earlycon is implemented currently.
+
endmenu

config SERIAL_MCTRL_GPIO
diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
index daac675612df..8c303736b7e8 100644
--- a/drivers/tty/serial/Makefile
+++ b/drivers/tty/serial/Makefile
@@ -89,6 +89,7 @@ obj-$(CONFIG_SERIAL_MVEBU_UART) += mvebu-uart.o
obj-$(CONFIG_SERIAL_PIC32) += pic32_uart.o
obj-$(CONFIG_SERIAL_MPS2_UART) += mps2-uart.o
obj-$(CONFIG_SERIAL_OWL) += owl-uart.o
+obj-$(CONFIG_SERIAL_RDA) += rda-uart.o

# GPIOLIB helpers for modem control lines
obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o
diff --git a/drivers/tty/serial/rda-uart.c b/drivers/tty/serial/rda-uart.c
new file mode 100644
index 000000000000..284623eefaeb
--- /dev/null
+++ b/drivers/tty/serial/rda-uart.c
@@ -0,0 +1,831 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * RDA8810PL serial device driver
+ *
+ * Copyright RDA Microelectronics Company Limited
+ * Copyright (c) 2017 Andreas Färber
+ * Copyright (c) 2018 Manivannan Sadhasivam
+ */
+
+#include <linux/clk.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+
+#define RDA_UART_PORT_NUM 3
+#define RDA_UART_DEV_NAME "ttyRDA"
+
+#define RDA_UART_CTRL 0x00
+#define RDA_UART_STATUS 0x04
+#define RDA_UART_RXTX_BUFFER 0x08
+#define RDA_UART_IRQ_MASK 0x0c
+#define RDA_UART_IRQ_CAUSE 0x10
+#define RDA_UART_IRQ_TRIGGERS 0x14
+#define RDA_UART_CMD_SET 0x18
+#define RDA_UART_CMD_CLR 0x1c
+
+/* UART_CTRL Bits */
+#define RDA_UART_ENABLE BIT(0)
+#define RDA_UART_DBITS_8 BIT(1)
+#define RDA_UART_TX_SBITS_2 BIT(2)
+#define RDA_UART_PARITY_EN BIT(3)
+#define RDA_UART_PARITY(x) (((x) & 0x3) << 4)
+#define RDA_UART_PARITY_ODD RDA_UART_PARITY(0)
+#define RDA_UART_PARITY_EVEN RDA_UART_PARITY(1)
+#define RDA_UART_PARITY_SPACE RDA_UART_PARITY(2)
+#define RDA_UART_PARITY_MARK RDA_UART_PARITY(3)
+#define RDA_UART_DIV_MODE BIT(20)
+#define RDA_UART_IRDA_EN BIT(21)
+#define RDA_UART_DMA_EN BIT(22)
+#define RDA_UART_FLOW_CNT_EN BIT(23)
+#define RDA_UART_LOOP_BACK_EN BIT(24)
+#define RDA_UART_RX_LOCK_ERR BIT(25)
+#define RDA_UART_RX_BREAK_LEN(x) (((x) & 0xf) << 28)
+
+/* UART_STATUS Bits */
+#define RDA_UART_RX_FIFO(x) (((x) & 0x7f) << 0)
+#define RDA_UART_RX_FIFO_MASK (0x7f << 0)
+#define RDA_UART_TX_FIFO(x) (((x) & 0x1f) << 8)
+#define RDA_UART_TX_FIFO_MASK (0x1f << 8)
+#define RDA_UART_TX_ACTIVE BIT(14)
+#define RDA_UART_RX_ACTIVE BIT(15)
+#define RDA_UART_RX_OVERFLOW_ERR BIT(16)
+#define RDA_UART_TX_OVERFLOW_ERR BIT(17)
+#define RDA_UART_RX_PARITY_ERR BIT(18)
+#define RDA_UART_RX_FRAMING_ERR BIT(19)
+#define RDA_UART_RX_BREAK_INT BIT(20)
+#define RDA_UART_DCTS BIT(24)
+#define RDA_UART_CTS BIT(25)
+#define RDA_UART_DTR BIT(28)
+#define RDA_UART_CLK_ENABLED BIT(31)
+
+/* UART_RXTX_BUFFER Bits */
+#define RDA_UART_RX_DATA(x) (((x) & 0xff) << 0)
+#define RDA_UART_TX_DATA(x) (((x) & 0xff) << 0)
+
+/* UART_IRQ_MASK Bits */
+#define RDA_UART_TX_MODEM_STATUS BIT(0)
+#define RDA_UART_RX_DATA_AVAILABLE BIT(1)
+#define RDA_UART_TX_DATA_NEEDED BIT(2)
+#define RDA_UART_RX_TIMEOUT BIT(3)
+#define RDA_UART_RX_LINE_ERR BIT(4)
+#define RDA_UART_TX_DMA_DONE BIT(5)
+#define RDA_UART_RX_DMA_DONE BIT(6)
+#define RDA_UART_RX_DMA_TIMEOUT BIT(7)
+#define RDA_UART_DTR_RISE BIT(8)
+#define RDA_UART_DTR_FALL BIT(9)
+
+/* UART_IRQ_CAUSE Bits */
+#define RDA_UART_TX_MODEM_STATUS_U BIT(16)
+#define RDA_UART_RX_DATA_AVAILABLE_U BIT(17)
+#define RDA_UART_TX_DATA_NEEDED_U BIT(18)
+#define RDA_UART_RX_TIMEOUT_U BIT(19)
+#define RDA_UART_RX_LINE_ERR_U BIT(20)
+#define RDA_UART_TX_DMA_DONE_U BIT(21)
+#define RDA_UART_RX_DMA_DONE_U BIT(22)
+#define RDA_UART_RX_DMA_TIMEOUT_U BIT(23)
+#define RDA_UART_DTR_RISE_U BIT(24)
+#define RDA_UART_DTR_FALL_U BIT(25)
+
+/* UART_TRIGGERS Bits */
+#define RDA_UART_RX_TRIGGER(x) (((x) & 0x1f) << 0)
+#define RDA_UART_TX_TRIGGER(x) (((x) & 0xf) << 8)
+#define RDA_UART_AFC_LEVEL(x) (((x) & 0x1f) << 16)
+
+/* UART_CMD_SET Bits */
+#define RDA_UART_RI BIT(0)
+#define RDA_UART_DCD BIT(1)
+#define RDA_UART_DSR BIT(2)
+#define RDA_UART_TX_BREAK_CONTROL BIT(3)
+#define RDA_UART_TX_FINISH_N_WAIT BIT(4)
+#define RDA_UART_RTS BIT(5)
+#define RDA_UART_RX_FIFO_RESET BIT(6)
+#define RDA_UART_TX_FIFO_RESET BIT(7)
+
+#define RDA_UART_TX_FIFO_SIZE 16
+
+static struct uart_driver rda_uart_driver;
+
+struct rda_uart_port {
+ struct uart_port port;
+ struct clk *clk;
+};
+
+#define to_rda_uart_port(port) container_of(port, struct rda_uart_port, port)
+
+static struct rda_uart_port *rda_uart_ports[RDA_UART_PORT_NUM];
+
+static inline void rda_uart_write(struct uart_port *port, u32 val,
+ unsigned int off)
+{
+ writel(val, port->membase + off);
+}
+
+static inline u32 rda_uart_read(struct uart_port *port, unsigned int off)
+{
+ return readl(port->membase + off);
+}
+
+static unsigned int rda_uart_tx_empty(struct uart_port *port)
+{
+ unsigned long flags;
+ unsigned int ret;
+ u32 val;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ val = rda_uart_read(port, RDA_UART_STATUS);
+ ret = (val & RDA_UART_TX_FIFO_MASK) ? TIOCSER_TEMT : 0;
+
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ return ret;
+}
+
+static unsigned int rda_uart_get_mctrl(struct uart_port *port)
+{
+ unsigned int mctrl = 0;
+ u32 cmd_set, status;
+
+ cmd_set = rda_uart_read(port, RDA_UART_CMD_SET);
+ status = rda_uart_read(port, RDA_UART_STATUS);
+ if (cmd_set & RDA_UART_RTS)
+ mctrl |= TIOCM_RTS;
+ if (!(status & RDA_UART_CTS))
+ mctrl |= TIOCM_CTS;
+
+ return mctrl;
+}
+
+static void rda_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+ u32 val;
+
+ if (mctrl & TIOCM_RTS) {
+ val = rda_uart_read(port, RDA_UART_CMD_SET);
+ rda_uart_write(port, (val | RDA_UART_RTS), RDA_UART_CMD_SET);
+ } else {
+ /* Clear RTS to stop to receive. */
+ val = rda_uart_read(port, RDA_UART_CMD_CLR);
+ rda_uart_write(port, (val | RDA_UART_RTS), RDA_UART_CMD_CLR);
+ }
+
+ val = rda_uart_read(port, RDA_UART_CTRL);
+
+ if (mctrl & TIOCM_LOOP)
+ val |= RDA_UART_LOOP_BACK_EN;
+ else
+ val &= ~RDA_UART_LOOP_BACK_EN;
+
+ rda_uart_write(port, val, RDA_UART_CTRL);
+}
+
+static void rda_uart_stop_tx(struct uart_port *port)
+{
+ u32 val;
+
+ val = rda_uart_read(port, RDA_UART_IRQ_MASK);
+ val &= ~RDA_UART_TX_DATA_NEEDED;
+ rda_uart_write(port, val, RDA_UART_IRQ_MASK);
+
+ val = rda_uart_read(port, RDA_UART_CMD_SET);
+ val |= RDA_UART_TX_FIFO_RESET;
+ rda_uart_write(port, val, RDA_UART_CMD_SET);
+}
+
+static void rda_uart_stop_rx(struct uart_port *port)
+{
+ u32 val;
+
+ val = rda_uart_read(port, RDA_UART_IRQ_MASK);
+ val &= ~(RDA_UART_RX_DATA_AVAILABLE | RDA_UART_RX_TIMEOUT);
+ rda_uart_write(port, val, RDA_UART_IRQ_MASK);
+
+ /* Read Rx buffer before reset to avoid Rx timeout interrupt */
+ val = rda_uart_read(port, RDA_UART_RXTX_BUFFER);
+
+ val = rda_uart_read(port, RDA_UART_CMD_SET);
+ val |= RDA_UART_RX_FIFO_RESET;
+ rda_uart_write(port, val, RDA_UART_CMD_SET);
+}
+
+static void rda_uart_start_tx(struct uart_port *port)
+{
+ u32 val;
+
+ if (uart_tx_stopped(port)) {
+ rda_uart_stop_tx(port);
+ return;
+ }
+
+ val = rda_uart_read(port, RDA_UART_IRQ_MASK);
+ val |= RDA_UART_TX_DATA_NEEDED;
+ rda_uart_write(port, val, RDA_UART_IRQ_MASK);
+}
+
+static void rda_uart_change_baudrate(struct rda_uart_port *rda_port,
+ unsigned long baud)
+{
+ clk_set_rate(rda_port->clk, baud * 8);
+}
+
+static void rda_uart_set_termios(struct uart_port *port,
+ struct ktermios *termios,
+ struct ktermios *old)
+{
+ struct rda_uart_port *rda_port = to_rda_uart_port(port);
+ unsigned long flags;
+ unsigned int ctrl, cmd_set, cmd_clr, triggers;
+ unsigned int baud;
+ u32 irq_mask;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ baud = uart_get_baud_rate(port, termios, old, 9600, port->uartclk / 4);
+ rda_uart_change_baudrate(rda_port, baud);
+
+ ctrl = rda_uart_read(port, RDA_UART_CTRL);
+ cmd_set = rda_uart_read(port, RDA_UART_CMD_SET);
+ cmd_clr = rda_uart_read(port, RDA_UART_CMD_CLR);
+
+ switch (termios->c_cflag & CSIZE) {
+ case CS5:
+ case CS6:
+ dev_warn(port->dev, "bit size not supported, using 7 bits\n");
+ /* Fall through */
+ case CS7:
+ ctrl &= ~RDA_UART_DBITS_8;
+ break;
+ default:
+ ctrl |= RDA_UART_DBITS_8;
+ break;
+ }
+
+ /* stop bits */
+ if (termios->c_cflag & CSTOPB)
+ ctrl |= RDA_UART_TX_SBITS_2;
+ else
+ ctrl &= ~RDA_UART_TX_SBITS_2;
+
+ /* parity check */
+ if (termios->c_cflag & PARENB) {
+ ctrl |= RDA_UART_PARITY_EN;
+
+ /* Mark or Space parity */
+ if (termios->c_cflag & CMSPAR) {
+ if (termios->c_cflag & PARODD)
+ ctrl |= RDA_UART_PARITY_MARK;
+ else
+ ctrl |= RDA_UART_PARITY_SPACE;
+ } else if (termios->c_cflag & PARODD) {
+ ctrl |= RDA_UART_PARITY_ODD;
+ } else {
+ ctrl |= RDA_UART_PARITY_EVEN;
+ }
+ } else {
+ ctrl &= ~RDA_UART_PARITY_EN;
+ }
+
+ /* Hardware handshake (RTS/CTS) */
+ if (termios->c_cflag & CRTSCTS) {
+ ctrl |= RDA_UART_FLOW_CNT_EN;
+ cmd_set |= RDA_UART_RTS;
+ } else {
+ ctrl &= ~RDA_UART_FLOW_CNT_EN;
+ cmd_clr |= RDA_UART_RTS;
+ }
+
+ ctrl |= RDA_UART_ENABLE;
+ ctrl &= ~RDA_UART_DMA_EN;
+
+ triggers = (RDA_UART_AFC_LEVEL(20) | RDA_UART_RX_TRIGGER(16));
+ irq_mask = rda_uart_read(port, RDA_UART_IRQ_MASK);
+ rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
+
+ rda_uart_write(port, triggers, RDA_UART_IRQ_TRIGGERS);
+ rda_uart_write(port, ctrl, RDA_UART_CTRL);
+ rda_uart_write(port, cmd_set, RDA_UART_CMD_SET);
+ rda_uart_write(port, cmd_clr, RDA_UART_CMD_CLR);
+
+ rda_uart_write(port, irq_mask, RDA_UART_IRQ_MASK);
+
+ /* Don't rewrite B0 */
+ if (tty_termios_baud_rate(termios))
+ tty_termios_encode_baud_rate(termios, baud, baud);
+
+ /* update the per-port timeout */
+ uart_update_timeout(port, termios->c_cflag, baud);
+
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void rda_uart_send_chars(struct uart_port *port)
+{
+ struct circ_buf *xmit = &port->state->xmit;
+ unsigned int ch;
+ u32 val;
+
+ if (uart_tx_stopped(port))
+ return;
+
+ if (port->x_char) {
+ while (!(rda_uart_read(port, RDA_UART_STATUS) &
+ RDA_UART_TX_FIFO_MASK))
+ cpu_relax();
+
+ rda_uart_write(port, port->x_char, RDA_UART_RXTX_BUFFER);
+ port->icount.tx++;
+ port->x_char = 0;
+ }
+
+ while (rda_uart_read(port, RDA_UART_STATUS) & RDA_UART_TX_FIFO_MASK) {
+ if (uart_circ_empty(xmit))
+ break;
+
+ ch = xmit->buf[xmit->tail];
+ rda_uart_write(port, ch, RDA_UART_RXTX_BUFFER);
+ xmit->tail = (xmit->tail + 1) & (SERIAL_XMIT_SIZE - 1);
+ port->icount.tx++;
+ }
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(port);
+
+ if (!uart_circ_empty(xmit)) {
+ /* Re-enable Tx FIFO interrupt */
+ val = rda_uart_read(port, RDA_UART_IRQ_MASK);
+ val |= RDA_UART_TX_DATA_NEEDED;
+ rda_uart_write(port, val, RDA_UART_IRQ_MASK);
+ }
+}
+
+static void rda_uart_receive_chars(struct uart_port *port)
+{
+ u32 status, val;
+
+ status = rda_uart_read(port, RDA_UART_STATUS);
+ while ((status & RDA_UART_RX_FIFO_MASK)) {
+ char flag = TTY_NORMAL;
+
+ if (status & RDA_UART_RX_PARITY_ERR) {
+ port->icount.parity++;
+ flag = TTY_PARITY;
+ }
+
+ if (status & RDA_UART_RX_FRAMING_ERR) {
+ port->icount.frame++;
+ flag = TTY_FRAME;
+ }
+
+ if (status & RDA_UART_RX_OVERFLOW_ERR) {
+ port->icount.overrun++;
+ flag = TTY_OVERRUN;
+ }
+
+ val = rda_uart_read(port, RDA_UART_RXTX_BUFFER);
+ val &= 0xff;
+
+ port->icount.rx++;
+ tty_insert_flip_char(&port->state->port, val, flag);
+
+ status = rda_uart_read(port, RDA_UART_STATUS);
+ }
+
+ spin_unlock(&port->lock);
+ tty_flip_buffer_push(&port->state->port);
+ spin_lock(&port->lock);
+}
+
+static irqreturn_t rda_interrupt(int irq, void *dev_id)
+{
+ struct uart_port *port = dev_id;
+ unsigned long flags;
+ u32 val, irq_mask;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ /* Clear IRQ cause */
+ val = rda_uart_read(port, RDA_UART_IRQ_CAUSE);
+ rda_uart_write(port, val, RDA_UART_IRQ_CAUSE);
+
+ if (val & (RDA_UART_RX_DATA_AVAILABLE | RDA_UART_RX_TIMEOUT))
+ rda_uart_receive_chars(port);
+
+ if (val & (RDA_UART_TX_DATA_NEEDED)) {
+ irq_mask = rda_uart_read(port, RDA_UART_IRQ_MASK);
+ irq_mask &= ~RDA_UART_TX_DATA_NEEDED;
+ rda_uart_write(port, irq_mask, RDA_UART_IRQ_MASK);
+
+ rda_uart_send_chars(port);
+ }
+
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ return IRQ_HANDLED;
+}
+
+static int rda_uart_startup(struct uart_port *port)
+{
+ unsigned long flags;
+ int ret;
+ u32 val;
+
+ spin_lock_irqsave(&port->lock, flags);
+ rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ ret = request_irq(port->irq, rda_interrupt, IRQF_NO_SUSPEND,
+ "rda-uart", port);
+ if (ret)
+ return ret;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ val = rda_uart_read(port, RDA_UART_CTRL);
+ val |= RDA_UART_ENABLE;
+ rda_uart_write(port, val, RDA_UART_CTRL);
+
+ /* enable rx interrupt */
+ val = rda_uart_read(port, RDA_UART_IRQ_MASK);
+ val |= (RDA_UART_RX_DATA_AVAILABLE | RDA_UART_RX_TIMEOUT);
+ rda_uart_write(port, val, RDA_UART_IRQ_MASK);
+
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ return 0;
+}
+
+static void rda_uart_shutdown(struct uart_port *port)
+{
+ unsigned long flags;
+ u32 val;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ rda_uart_stop_tx(port);
+ rda_uart_stop_rx(port);
+
+ val = rda_uart_read(port, RDA_UART_CTRL);
+ val &= ~RDA_UART_ENABLE;
+ rda_uart_write(port, val, RDA_UART_CTRL);
+
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *rda_uart_type(struct uart_port *port)
+{
+ return (port->type == PORT_RDA) ? "rda-uart" : NULL;
+}
+
+static int rda_uart_request_port(struct uart_port *port)
+{
+ struct platform_device *pdev = to_platform_device(port->dev);
+ struct resource *res;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENXIO;
+
+ if (!devm_request_mem_region(port->dev, port->mapbase,
+ resource_size(res), dev_name(port->dev)))
+ return -EBUSY;
+
+ if (port->flags & UPF_IOREMAP) {
+ port->membase = devm_ioremap_nocache(port->dev, port->mapbase,
+ resource_size(res));
+ if (!port->membase)
+ return -EBUSY;
+ }
+
+ return 0;
+}
+
+static void rda_uart_config_port(struct uart_port *port, int flags)
+{
+ unsigned long irq_flags;
+
+ if (flags & UART_CONFIG_TYPE) {
+ port->type = PORT_RDA;
+ rda_uart_request_port(port);
+ }
+
+ spin_lock_irqsave(&port->lock, irq_flags);
+
+ /* Clear mask, so no surprise interrupts. */
+ rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
+
+ /* Clear status register */
+ rda_uart_write(port, 0, RDA_UART_STATUS);
+
+ spin_unlock_irqrestore(&port->lock, irq_flags);
+}
+
+static void rda_uart_release_port(struct uart_port *port)
+{
+ struct platform_device *pdev = to_platform_device(port->dev);
+ struct resource *res;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return;
+
+ if (port->flags & UPF_IOREMAP) {
+ devm_release_mem_region(port->dev, port->mapbase,
+ resource_size(res));
+ devm_iounmap(port->dev, port->membase);
+ port->membase = NULL;
+ }
+}
+
+static int rda_uart_verify_port(struct uart_port *port,
+ struct serial_struct *ser)
+{
+ if (port->type != PORT_RDA)
+ return -EINVAL;
+
+ if (port->irq != ser->irq)
+ return -EINVAL;
+
+ return 0;
+}
+
+static const struct uart_ops rda_uart_ops = {
+ .tx_empty = rda_uart_tx_empty,
+ .get_mctrl = rda_uart_get_mctrl,
+ .set_mctrl = rda_uart_set_mctrl,
+ .start_tx = rda_uart_start_tx,
+ .stop_tx = rda_uart_stop_tx,
+ .stop_rx = rda_uart_stop_rx,
+ .startup = rda_uart_startup,
+ .shutdown = rda_uart_shutdown,
+ .set_termios = rda_uart_set_termios,
+ .type = rda_uart_type,
+ .request_port = rda_uart_request_port,
+ .release_port = rda_uart_release_port,
+ .config_port = rda_uart_config_port,
+ .verify_port = rda_uart_verify_port,
+};
+
+#ifdef CONFIG_SERIAL_RDA_CONSOLE
+
+static void rda_console_putchar(struct uart_port *port, int ch)
+{
+ if (!port->membase)
+ return;
+
+ while (!(rda_uart_read(port, RDA_UART_STATUS) & RDA_UART_TX_FIFO_MASK))
+ cpu_relax();
+
+ rda_uart_write(port, ch, RDA_UART_RXTX_BUFFER);
+}
+
+static void rda_uart_port_write(struct uart_port *port, const char *s,
+ u_int count)
+{
+ u32 old_irq_mask;
+ unsigned long flags;
+ int locked;
+
+ local_irq_save(flags);
+
+ if (port->sysrq) {
+ locked = 0;
+ } else if (oops_in_progress) {
+ locked = spin_trylock(&port->lock);
+ } else {
+ spin_lock(&port->lock);
+ locked = 1;
+ }
+
+ old_irq_mask = rda_uart_read(port, RDA_UART_IRQ_MASK);
+ rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
+
+ uart_console_write(port, s, count, rda_console_putchar);
+
+ /* wait until all contents have been sent out */
+ while (!(rda_uart_read(port, RDA_UART_STATUS) & RDA_UART_TX_FIFO_MASK))
+ cpu_relax();
+
+ rda_uart_write(port, old_irq_mask, RDA_UART_IRQ_MASK);
+
+ if (locked)
+ spin_unlock(&port->lock);
+
+ local_irq_restore(flags);
+}
+
+static void rda_uart_console_write(struct console *co, const char *s,
+ u_int count)
+{
+ struct rda_uart_port *rda_port;
+
+ rda_port = rda_uart_ports[co->index];
+ if (!rda_port)
+ return;
+
+ rda_uart_port_write(&rda_port->port, s, count);
+}
+
+static int rda_uart_console_setup(struct console *co, char *options)
+{
+ struct rda_uart_port *rda_port;
+ int baud = 921600;
+ int bits = 8;
+ int parity = 'n';
+ int flow = 'n';
+
+ if (co->index < 0 || co->index >= RDA_UART_PORT_NUM)
+ return -EINVAL;
+
+ rda_port = rda_uart_ports[co->index];
+ if (!rda_port || !rda_port->port.membase)
+ return -ENODEV;
+
+ if (options)
+ uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+ return uart_set_options(&rda_port->port, co, baud, parity, bits, flow);
+}
+
+static struct console rda_uart_console = {
+ .name = RDA_UART_DEV_NAME,
+ .write = rda_uart_console_write,
+ .device = uart_console_device,
+ .setup = rda_uart_console_setup,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+ .data = &rda_uart_driver,
+};
+
+static int __init rda_uart_console_init(void)
+{
+ register_console(&rda_uart_console);
+
+ return 0;
+}
+console_initcall(rda_uart_console_init);
+
+static void rda_uart_early_console_write(struct console *co,
+ const char *s,
+ u_int count)
+{
+ struct earlycon_device *dev = co->data;
+
+ rda_uart_port_write(&dev->port, s, count);
+}
+
+static int __init
+rda_uart_early_console_setup(struct earlycon_device *device, const char *opt)
+{
+ if (!device->port.membase)
+ return -ENODEV;
+
+ device->con->write = rda_uart_early_console_write;
+
+ return 0;
+}
+
+OF_EARLYCON_DECLARE(rda, "rda,8810pl-uart",
+ rda_uart_early_console_setup);
+
+#define RDA_UART_CONSOLE (&rda_uart_console)
+#else
+#define RDA_UART_CONSOLE NULL
+#endif /* CONFIG_SERIAL_RDA_CONSOLE */
+
+static struct uart_driver rda_uart_driver = {
+ .owner = THIS_MODULE,
+ .driver_name = "rda-uart",
+ .dev_name = RDA_UART_DEV_NAME,
+ .nr = RDA_UART_PORT_NUM,
+ .cons = RDA_UART_CONSOLE,
+};
+
+static const struct of_device_id rda_uart_dt_matches[] = {
+ { .compatible = "rda,8810pl-uart" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, rda_uart_dt_matches);
+
+static int rda_uart_probe(struct platform_device *pdev)
+{
+ struct resource *res_mem;
+ struct rda_uart_port *rda_port;
+ int ret, irq;
+
+ if (pdev->dev.of_node)
+ pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
+
+ if (pdev->id < 0 || pdev->id >= RDA_UART_PORT_NUM) {
+ dev_err(&pdev->dev, "id %d out of range\n", pdev->id);
+ return -EINVAL;
+ }
+
+ res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res_mem) {
+ dev_err(&pdev->dev, "could not get mem\n");
+ return -ENODEV;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "could not get irq\n");
+ return irq;
+ }
+
+ if (rda_uart_ports[pdev->id]) {
+ dev_err(&pdev->dev, "port %d already allocated\n", pdev->id);
+ return -EBUSY;
+ }
+
+ rda_port = devm_kzalloc(&pdev->dev, sizeof(*rda_port), GFP_KERNEL);
+ if (!rda_port)
+ return -ENOMEM;
+
+ rda_port->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(rda_port->clk)) {
+ dev_err(&pdev->dev, "could not get clk\n");
+ return PTR_ERR(rda_port->clk);
+ }
+
+ rda_port->port.dev = &pdev->dev;
+ rda_port->port.regshift = 0;
+ rda_port->port.line = pdev->id;
+ rda_port->port.type = PORT_RDA;
+ rda_port->port.iotype = UPIO_MEM;
+ rda_port->port.mapbase = res_mem->start;
+ rda_port->port.irq = irq;
+ rda_port->port.uartclk = clk_get_rate(rda_port->clk);
+ if (rda_port->port.uartclk == 0) {
+ dev_err(&pdev->dev, "clock rate is zero\n");
+ return -EINVAL;
+ }
+ rda_port->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP |
+ UPF_LOW_LATENCY;
+ rda_port->port.x_char = 0;
+ rda_port->port.fifosize = RDA_UART_TX_FIFO_SIZE;
+ rda_port->port.ops = &rda_uart_ops;
+
+ rda_uart_ports[pdev->id] = rda_port;
+ platform_set_drvdata(pdev, rda_port);
+
+ ret = uart_add_one_port(&rda_uart_driver, &rda_port->port);
+ if (ret)
+ rda_uart_ports[pdev->id] = NULL;
+
+ return ret;
+}
+
+static int rda_uart_remove(struct platform_device *pdev)
+{
+ struct rda_uart_port *rda_port = platform_get_drvdata(pdev);
+
+ uart_remove_one_port(&rda_uart_driver, &rda_port->port);
+ rda_uart_ports[pdev->id] = NULL;
+
+ return 0;
+}
+
+static struct platform_driver rda_uart_platform_driver = {
+ .probe = rda_uart_probe,
+ .remove = rda_uart_remove,
+ .driver = {
+ .name = "rda-uart",
+ .of_match_table = rda_uart_dt_matches,
+ },
+};
+
+static int __init rda_uart_init(void)
+{
+ int ret;
+
+ ret = uart_register_driver(&rda_uart_driver);
+ if (ret)
+ return ret;
+
+ ret = platform_driver_register(&rda_uart_platform_driver);
+ if (ret)
+ uart_unregister_driver(&rda_uart_driver);
+
+ return ret;
+}
+
+static void __init rda_uart_exit(void)
+{
+ platform_driver_unregister(&rda_uart_platform_driver);
+ uart_unregister_driver(&rda_uart_driver);
+}
+
+module_init(rda_uart_init);
+module_exit(rda_uart_exit);
+
+MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
+MODULE_DESCRIPTION("RDA8810PL serial device driver");
+MODULE_LICENSE("GPL");
diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
index dce5f9dae121..df4a7534e239 100644
--- a/include/uapi/linux/serial_core.h
+++ b/include/uapi/linux/serial_core.h
@@ -281,4 +281,7 @@
/* MediaTek BTIF */
#define PORT_MTK_BTIF 117

+/* RDA UART */
+#define PORT_RDA 118
+
#endif /* _UAPILINUX_SERIAL_CORE_H */
--
2.17.1