[PATCH v3 5/5] tty/serial: Add Spreadtrum sc9836-uart driver support

Murali Karicheri
2014-11-26T18:29:16Z

On 11/25/2014 07:16 AM, Chunyan Zhang wrote:
> Add a full sc9836-uart driver for SC9836 SoC which is based on the
> spreadtrum sharkl64 platform.
> This driver also support earlycon.
>
> Signed-off-by: Chunyan Zhang<chunyan.zhang@spreadtrum.com>
> Signed-off-by: Orson Zhai<orson.zhai@spreadtrum.com>
> Originally-by: Lanqing Liu<lanqing.liu@spreadtrum.com>
> ---
> Documentation/devices.txt | 3 +
> drivers/tty/serial/Kconfig | 23 ++
> drivers/tty/serial/Makefile | 1 +
> drivers/tty/serial/sprd_serial.c | 752 ++++++++++++++++++++++++++++++++++++++
> include/uapi/linux/serial_core.h | 3 +
> 5 files changed, 782 insertions(+)
> create mode 100644 drivers/tty/serial/sprd_serial.c
>
> diff --git a/Documentation/devices.txt b/Documentation/devices.txt
> index 87b4c5e..1da0432 100644
> --- a/Documentation/devices.txt
> +++ b/Documentation/devices.txt
> @@ -2816,6 +2816,9 @@ Your cooperation is appreciated.
> 210 = /dev/ttyMAX1 MAX3100 serial port 1
> 211 = /dev/ttyMAX2 MAX3100 serial port 2
> 212 = /dev/ttyMAX3 MAX3100 serial port 3
> + 213 = /dev/ttySPX0 SPRD serial port 0
> + ...
> + 216 = /dev/ttySPX3 SPRD serial port 3
>
> 205 char Low-density serial ports (alternate device)
> 0 = /dev/culu0 Callout device for ttyLU0
> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
> index 649b784..2c2cf60 100644
> --- a/drivers/tty/serial/Kconfig
> +++ b/drivers/tty/serial/Kconfig
> @@ -1573,6 +1573,29 @@ config SERIAL_MEN_Z135
> This driver can also be build as a module. If so, the module will be called
> men_z135_uart.ko
>
> +config SERIAL_SPRD
> + tristate "Support for SPRD serial"
> + depends on ARCH_SPRD
> + select SERIAL_CORE
> + help
> + This enables the driver for the Spreadtrum's serial.
> +
> +config SERIAL_SPRD_NR
> + int "Maximum number of sprd serial ports"
> + depends on SERIAL_SPRD
> + default "4"
> +
> +config SERIAL_SPRD_CONSOLE
> + bool "SPRD UART console support"
> + depends on SERIAL_SPRD=y
> + select SERIAL_CORE_CONSOLE
> + select SERIAL_EARLYCON
> + help
> + Support for early debug console using Spreadtrum's serial. This enables
> + the console before standard serial driver is probed. This is enabled
> + with "earlycon" on the kernel command line. The console is
> + enabled when early_param is processed.
> +
> endmenu
>
> config SERIAL_MCTRL_GPIO
> diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
> index 9a548ac..4801aca 100644
> --- a/drivers/tty/serial/Makefile
> +++ b/drivers/tty/serial/Makefile
> @@ -93,6 +93,7 @@ obj-$(CONFIG_SERIAL_ARC) += arc_uart.o
> obj-$(CONFIG_SERIAL_RP2) += rp2.o
> obj-$(CONFIG_SERIAL_FSL_LPUART) += fsl_lpuart.o
> obj-$(CONFIG_SERIAL_MEN_Z135) += men_z135_uart.o
> +obj-$(CONFIG_SERIAL_SPRD) += sprd_serial.o
>
> # GPIOLIB helpers for modem control lines
> obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o
> diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c
> new file mode 100644
> index 0000000..58214c8
> --- /dev/null
> +++ b/drivers/tty/serial/sprd_serial.c
> @@ -0,0 +1,752 @@
> +/*
> + * Copyright (C) 2012 Spreadtrum Communications Inc.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + */
> +
> +#include<linux/module.h>
> +#include<linux/tty.h>
> +#include<linux/ioport.h>
> +#include<linux/console.h>
> +#include<linux/platform_device.h>
> +#include<linux/tty_flip.h>
> +#include<linux/serial_core.h>
> +#include<linux/serial.h>
> +#include<linux/delay.h>
> +#include<linux/io.h>
> +#include<asm/irq.h>
> +#include<linux/slab.h>
> +#include<linux/of.h>
> +#include<linux/kernel.h>
> +#include<linux/slab.h>
> +#include<linux/clk.h>
How about sorting this includes? asm/irq.h go first followed linux/ in
alphabatical order?
> +
> +/* device name */
> +#define UART_NR_MAX CONFIG_SERIAL_SPRD_NR
> +#define SPRD_TTY_NAME "ttySPX"
> +#define SPRD_TTY_MAJOR 204
> +#define SPRD_TTY_MINOR_START 213
> +#define SPRD_FIFO_SIZE 128
> +#define SPRD_DEF_RATE 26000000
> +
> +/* the offset of serial registers and BITs for them */
> +/* data registers */
> +#define SPRD_TXD 0x0000
> +#define SPRD_RXD 0x0004
> +
> +/* line status register and its BITs */
> +#define SPRD_LSR 0x0008
> +#define SPRD_LSR_OE BIT(4)
> +#define SPRD_LSR_FE BIT(3)
> +#define SPRD_LSR_PE BIT(2)
> +#define SPRD_LSR_BI BIT(7)
> +#define SPRD_LSR_TX_OVER BIT(15)
> +
> +/* data number in TX and RX fifo */
> +#define SPRD_STS1 0x000C
> +
> +/* interrupt enable register and its BITs */
> +#define SPRD_IEN 0x0010
> +#define SPRD_IEN_RX_FULL BIT(0)
> +#define SPRD_IEN_TX_EMPTY BIT(1)
> +#define SPRD_IEN_BREAK_DETECT BIT(7)
> +#define SPRD_IEN_TIMEOUT BIT(13)
> +
> +/* interrupt clear register */
> +#define SPRD_ICLR 0x0014
> +
> +/* line control register */
> +#define SPRD_LCR 0x0018
> +#define SPRD_LCR_STOP_1BIT 0x10
> +#define SPRD_LCR_STOP_2BIT 0x30
> +#define SPRD_LCR_DATA_LEN (BIT(2) | BIT(3))
> +#define SPRD_LCR_DATA_LEN5 0x0
> +#define SPRD_LCR_DATA_LEN6 0x4
> +#define SPRD_LCR_DATA_LEN7 0x8
> +#define SPRD_LCR_DATA_LEN8 0xc
> +#define SPRD_LCR_PARITY (BIT(0) | BIT(1))
> +#define SPRD_LCR_PARITY_EN 0x2
> +#define SPRD_LCR_EVEN_PAR 0x0
> +#define SPRD_LCR_ODD_PAR 0x1
> +
> +/* control register 1 */
> +#define SPRD_CTL1 0x001C
> +#define RX_HW_FLOW_CTL_THLD BIT(6)
> +#define RX_HW_FLOW_CTL_EN BIT(7)
> +#define TX_HW_FLOW_CTL_EN BIT(8)
> +
> +/* fifo threshold register */
> +#define SPRD_CTL2 0x0020
> +#define THLD_TX_EMPTY 0x40
> +#define THLD_RX_FULL 0x40
> +
> +/* config baud rate register */
> +#define SPRD_CLKD0 0x0024
> +#define SPRD_CLKD1 0x0028
> +
> +/* interrupt mask status register */
> +#define SPRD_IMSR 0x002C
> +#define SPRD_IMSR_RX_FIFO_FULL BIT(0)
> +#define SPRD_IMSR_TX_FIFO_EMPTY BIT(1)
> +#define SPRD_IMSR_BREAK_DETECT BIT(7)
> +#define SPRD_IMSR_TIMEOUT BIT(13)
> +
> +struct reg_backup {
> + uint32_t ien;
> + uint32_t ctrl0;
> + uint32_t ctrl1;
> + uint32_t ctrl2;
> + uint32_t clkd0;
> + uint32_t clkd1;
> + uint32_t dspwait;
> +};
> +struct sprd_uart_port {
> + struct uart_port port;
> + struct reg_backup reg_bak;
> + char name[16];
> +};
> +static struct sprd_uart_port *sprd_port[UART_NR_MAX] = { NULL };
> +
> +static inline unsigned int serial_in(struct uart_port *port, int offset)
> +{
> + return readl_relaxed(port->membase + offset);
> +}
> +
> +static inline void serial_out(struct uart_port *port, int offset, int value)
> +{
> + writel_relaxed(value, port->membase + offset);
> +}
> +
> +static unsigned int sprd_tx_empty(struct uart_port *port)
> +{
> + if (serial_in(port, SPRD_STS1)& 0xff00)
> + return 0;
> + else
> + return TIOCSER_TEMT;
> +}
> +
> +static unsigned int sprd_get_mctrl(struct uart_port *port)
> +{
> + return TIOCM_DSR | TIOCM_CTS;
> +}
> +
> +static void sprd_set_mctrl(struct uart_port *port, unsigned int mctrl)
> +{
> + /* nothing to do */
> +}
> +
> +static void sprd_stop_tx(struct uart_port *port)
> +{
> + unsigned int ien, iclr;
> +
> + iclr = serial_in(port, SPRD_ICLR);
> + ien = serial_in(port, SPRD_IEN);
> +
> + iclr |= SPRD_IEN_TX_EMPTY;
> + ien&= ~SPRD_IEN_TX_EMPTY;
> +
> + serial_out(port, SPRD_ICLR, iclr);
> + serial_out(port, SPRD_IEN, ien);
> +}
> +
> +static void sprd_start_tx(struct uart_port *port)
> +{
> + unsigned int ien;
> +
> + ien = serial_in(port, SPRD_IEN);
> + if (!(ien& SPRD_IEN_TX_EMPTY)) {
> + ien |= SPRD_IEN_TX_EMPTY;
> + serial_out(port, SPRD_IEN, ien);
> + }
> +}
> +
> +static void sprd_stop_rx(struct uart_port *port)
> +{
> + unsigned int ien, iclr;
> +
> + iclr = serial_in(port, SPRD_ICLR);
> + ien = serial_in(port, SPRD_IEN);
> +
> + ien&= ~(SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT);
> + iclr |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT;
> +
> + serial_out(port, SPRD_IEN, ien);
> + serial_out(port, SPRD_ICLR, iclr);
> +}
> +
> +/* The Sprd serial does not support this function. */
> +static void sprd_break_ctl(struct uart_port *port, int break_state)
> +{
> + /* nothing to do */
> +}
> +
> +static inline int handle_lsr_errors(struct uart_port *port,
> + unsigned int *flag, unsigned int *lsr)
> +{
> + int ret = 0;
> +
> + /* stastics */
> + if (*lsr& SPRD_LSR_BI) {
> + *lsr&= ~(SPRD_LSR_FE | SPRD_LSR_PE);
> + port->icount.brk++;
> + ret = uart_handle_break(port);
> + if (ret)
> + return ret;
> + } else if (*lsr& SPRD_LSR_PE)
> + port->icount.parity++;
> + else if (*lsr& SPRD_LSR_FE)
> + port->icount.frame++;
> + if (*lsr& SPRD_LSR_OE)
> + port->icount.overrun++;
> +
> + /* mask off conditions which should be ignored */
> + *lsr&= port->read_status_mask;
> + if (*lsr& SPRD_LSR_BI)
> + *flag = TTY_BREAK;
> + else if (*lsr& SPRD_LSR_PE)
> + *flag = TTY_PARITY;
> + else if (*lsr& SPRD_LSR_FE)
> + *flag = TTY_FRAME;
> +
> + return ret;
> +}
> +
> +static inline void sprd_rx(int irq, void *dev_id)
> +{
> + struct uart_port *port = (struct uart_port *)dev_id;
> + struct tty_port *tty =&port->state->port;
> + unsigned int ch, flag, lsr, max_count = 2048;
> +
> + while ((serial_in(port, SPRD_STS1)& 0x00ff)&& max_count--) {
> + lsr = serial_in(port, SPRD_LSR);
> + ch = serial_in(port, SPRD_RXD);
> + flag = TTY_NORMAL;
> + port->icount.rx++;
> +
> + if (unlikely(lsr& (SPRD_LSR_BI | SPRD_LSR_PE
> + | SPRD_LSR_FE | SPRD_LSR_OE)))
> + if (handle_lsr_errors(port,&lsr,&flag))
> + continue;
> + if (uart_handle_sysrq_char(port, ch))
> + continue;
> +
> + uart_insert_char(port, lsr, SPRD_LSR_OE, ch, flag);
> + }
> +
> + tty_flip_buffer_push(tty);
> +}
> +
> +static inline void sprd_tx(int irq, void *dev_id)
> +{
> + struct uart_port *port = dev_id;
> + struct circ_buf *xmit =&port->state->xmit;
> + int count;
> +
> + if (port->x_char) {
> + serial_out(port, SPRD_TXD, port->x_char);
> + port->icount.tx++;
> + port->x_char = 0;
> + return;
> + }
> + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
> + sprd_stop_tx(port);
> + return;
> + }
> + count = THLD_TX_EMPTY;
> + do {
> + serial_out(port, SPRD_TXD, xmit->buf[xmit->tail]);
> + xmit->tail = (xmit->tail + 1)& (UART_XMIT_SIZE - 1);
> + port->icount.tx++;
> + if (uart_circ_empty(xmit))
> + break;
> + } while (--count> 0);
> +
> + if (uart_circ_chars_pending(xmit)< WAKEUP_CHARS)
> + uart_write_wakeup(port);
> +
> + if (uart_circ_empty(xmit))
> + sprd_stop_tx(port);
> +}
> +
> +/*
> + *this handles the interrupt from one port
> + */
> +static irqreturn_t sprd_handle_irq(int irq, void *dev_id)
> +{
> + struct uart_port *port = (struct uart_port *)dev_id;
> + u32 ims;
> +
> + ims = serial_in(port, SPRD_IMSR);
> +
> + serial_out(port, SPRD_ICLR, ~0);
> +
> + if (ims& (SPRD_IMSR_RX_FIFO_FULL |
> + SPRD_IMSR_BREAK_DETECT | SPRD_IMSR_TIMEOUT)) {
> + sprd_rx(irq, port);
> + }
> + if (ims& SPRD_IMSR_TX_FIFO_EMPTY)
> + sprd_tx(irq, port);
> +
> + return IRQ_HANDLED;
You are always returning IRQ_HANDLED and this is registered as a SHARED
irq. Is there a chance this handler is called and the irq event doesn't
belong to this device?

Murali
> +}
> +
> +static int sprd_startup(struct uart_port *port)
> +{
> + int ret = 0;
> + unsigned int ien, ctrl1;
> + struct sprd_uart_port *sp;
> +
> + serial_out(port, SPRD_CTL2, ((THLD_TX_EMPTY<< 8) | THLD_RX_FULL));
> +
> + /* clear rx fifo */
> + while (serial_in(port, SPRD_STS1)& 0x00ff)
> + serial_in(port, SPRD_RXD);
> +
> + /* clear tx fifo */
> + while (serial_in(port, SPRD_STS1)& 0xff00)
> + ;
> +
> + /* clear interrupt */
> + serial_out(port, SPRD_IEN, 0x0);
> + serial_out(port, SPRD_ICLR, ~0);
> +
> + /* allocate irq */
> + sp = container_of(port, struct sprd_uart_port, port);
> + snprintf(sp->name, sizeof(sp->name), "sprd_serial%d", port->line);
> + ret = devm_request_irq(port->dev, port->irq, sprd_handle_irq,
> + IRQF_SHARED, sp->name, port);
> + if (ret) {
> + dev_err(port->dev, "fail to request serial irq %d\n",
> + port->irq);
> + return ret;
> + }
> + ctrl1 = serial_in(port, SPRD_CTL1);
> + ctrl1 |= 0x3e00 | THLD_RX_FULL;
> + serial_out(port, SPRD_CTL1, ctrl1);
> +
> + /* enable interrupt */
> + spin_lock(&port->lock);
> + ien = serial_in(port, SPRD_IEN);
> + ien |= SPRD_IEN_RX_FULL | SPRD_IEN_BREAK_DETECT | SPRD_IEN_TIMEOUT;
> + serial_out(port, SPRD_IEN, ien);
> + spin_unlock(&port->lock);
> +
> + return 0;
> +}
> +
> +static void sprd_shutdown(struct uart_port *port)
> +{
> + serial_out(port, SPRD_IEN, 0x0);
> + serial_out(port, SPRD_ICLR, ~0);
> + devm_free_irq(port->dev, port->irq, port);
> +}
> +
> +static void sprd_set_termios(struct uart_port *port,
> + struct ktermios *termios,
> + struct ktermios *old)
> +{
> + unsigned int baud, quot;
> + unsigned int lcr, fc;
> +
> + /* ask the core to calculate the divisor for us */
> + baud = uart_get_baud_rate(port, termios, old, 1200, 3000000);
> +
> + quot = (unsigned int)((port->uartclk + baud / 2) / baud);
> +
> + /* set data length */
> + lcr = serial_in(port, SPRD_LCR);
> + lcr&= ~SPRD_LCR_DATA_LEN;
> + switch (termios->c_cflag& CSIZE) {
> + case CS5:
> + lcr |= SPRD_LCR_DATA_LEN5;
> + break;
> + case CS6:
> + lcr |= SPRD_LCR_DATA_LEN6;
> + break;
> + case CS7:
> + lcr |= SPRD_LCR_DATA_LEN7;
> + break;
> + case CS8:
> + default:
> + lcr |= SPRD_LCR_DATA_LEN8;
> + break;
> + }
> +
> + /* calculate stop bits */
> + lcr&= ~(SPRD_LCR_STOP_1BIT | SPRD_LCR_STOP_2BIT);
> + if (termios->c_cflag& CSTOPB)
> + lcr |= SPRD_LCR_STOP_2BIT;
> + else
> + lcr |= SPRD_LCR_STOP_1BIT;
> +
> + /* calculate parity */
> + lcr&= ~SPRD_LCR_PARITY;
> + if (termios->c_cflag& PARENB) {
> + lcr |= SPRD_LCR_PARITY_EN;
> + if (termios->c_cflag& PARODD)
> + lcr |= SPRD_LCR_ODD_PAR;
> + else
> + lcr |= SPRD_LCR_EVEN_PAR;
> + }
> +
> + /* change the port state. */
> + /* update the per-port timeout */
> + uart_update_timeout(port, termios->c_cflag, baud);
> +
> + port->read_status_mask = SPRD_LSR_OE;
> + if (termios->c_iflag& INPCK)
> + port->read_status_mask |= SPRD_LSR_FE | SPRD_LSR_PE;
> + if (termios->c_iflag& (BRKINT | PARMRK))
> + port->read_status_mask |= SPRD_LSR_BI;
> +
> + /* characters to ignore */
> + port->ignore_status_mask = 0;
> + if (termios->c_iflag& IGNPAR)
> + port->ignore_status_mask |= SPRD_LSR_PE | SPRD_LSR_FE;
> + if (termios->c_iflag& IGNBRK) {
> + port->ignore_status_mask |= SPRD_LSR_BI;
> + /*
> + * If we're ignoring parity and break indicators,
> + * ignore overruns too (for real raw support).
> + */
> + if (termios->c_iflag& IGNPAR)
> + port->ignore_status_mask |= SPRD_LSR_OE;
> + }
> +
> + /* flow control */
> + fc = serial_in(port, SPRD_CTL1);
> + fc&= ~(RX_HW_FLOW_CTL_THLD | RX_HW_FLOW_CTL_EN | TX_HW_FLOW_CTL_EN);
> + if (termios->c_cflag& CRTSCTS) {
> + fc |= RX_HW_FLOW_CTL_THLD;
> + fc |= RX_HW_FLOW_CTL_EN;
> + fc |= TX_HW_FLOW_CTL_EN;
> + }
> +
> + /* clock divider bit0~bit15 */
> + serial_out(port, SPRD_CLKD0, quot& 0xffff);
> +
> + /* clock divider bit16~bit20 */
> + serial_out(port, SPRD_CLKD1, (quot& 0x1f0000)>> 16);
> + serial_out(port, SPRD_LCR, lcr);
> + fc |= 0x3e00 | THLD_RX_FULL;
> + serial_out(port, SPRD_CTL1, fc);
> +}
> +
> +static const char *sprd_type(struct uart_port *port)
> +{
> + return "SPX";
> +}
> +
> +static void sprd_release_port(struct uart_port *port)
> +{
> + /* nothing to do */
> +}
> +
> +static int sprd_request_port(struct uart_port *port)
> +{
> + return 0;
> +}
> +
> +static void sprd_config_port(struct uart_port *port, int flags)
> +{
> + if (flags& UART_CONFIG_TYPE)
> + port->type = PORT_SPRD;
> +}
> +
> +static int sprd_verify_port(struct uart_port *port,
> + struct serial_struct *ser)
> +{
> + if (unlikely(ser->type != PORT_SPRD))
> + return -EINVAL;
> + if (unlikely(port->irq != ser->irq))
> + return -EINVAL;
> + return 0;
> +}
> +
> +static struct uart_ops serial_sprd_ops = {
> + .tx_empty = sprd_tx_empty,
> + .get_mctrl = sprd_get_mctrl,
> + .set_mctrl = sprd_set_mctrl,
> + .stop_tx = sprd_stop_tx,
> + .start_tx = sprd_start_tx,
> + .stop_rx = sprd_stop_rx,
> + .break_ctl = sprd_break_ctl,
> + .startup = sprd_startup,
> + .shutdown = sprd_shutdown,
> + .set_termios = sprd_set_termios,
> + .type = sprd_type,
> + .release_port = sprd_release_port,
> + .request_port = sprd_request_port,
> + .config_port = sprd_config_port,
> + .verify_port = sprd_verify_port,
> +};
> +
> +#ifdef CONFIG_SERIAL_SPRD_CONSOLE
> +static inline void wait_for_xmitr(struct uart_port *port)
> +{
> + unsigned int status, tmout = 10000;
> +
> + /* wait up to 10ms for the character(s) to be sent */
> + do {
> + status = serial_in(port, SPRD_STS1);
> + if (--tmout == 0)
> + break;
> + udelay(1);
> + } while (status& 0xff00);
> +}
> +
> +static void sprd_console_putchar(struct uart_port *port, int ch)
> +{
> + wait_for_xmitr(port);
> + serial_out(port, SPRD_TXD, ch);
> +}
> +
> +static void sprd_console_write(struct console *co, const char *s,
> + unsigned int count)
> +{
> + struct uart_port *port = (struct uart_port *)sprd_port[co->index];
> + int ien;
> + int locked = 1;
> +
> + if (oops_in_progress)
> + locked = spin_trylock(&port->lock);
> + else
> + spin_lock(&port->lock);
> + /* save the IEN then disable the interrupts */
> + ien = serial_in(port, SPRD_IEN);
> + serial_out(port, SPRD_IEN, 0x0);
> +
> + uart_console_write(port, s, count, sprd_console_putchar);
> +
> + /* wait for transmitter to become empty and restore the IEN */
> + wait_for_xmitr(port);
> + serial_out(port, SPRD_IEN, ien);
> + if (locked)
> + spin_unlock(&port->lock);
> +}
> +
> +static int __init sprd_console_setup(struct console *co, char *options)
> +{
> + struct uart_port *port;
> + int baud = 115200;
> + int bits = 8;
> + int parity = 'n';
> + int flow = 'n';
> +
> + if (unlikely(co->index>= UART_NR_MAX || co->index< 0))
> + co->index = 0;
> +
> + port = (struct uart_port *)sprd_port[co->index];
> + if (port == NULL) {
> + pr_info("srial port %d not yet initialized\n", co->index);
> + return -ENODEV;
> + }
> + if (options)
> + uart_parse_options(options,&baud,&parity,&bits,&flow);
> +
> + return uart_set_options(port, co, baud, parity, bits, flow);
> +}
> +
> +static struct uart_driver sprd_uart_driver;
> +static struct console sprd_console = {
> + .name = SPRD_TTY_NAME,
> + .write = sprd_console_write,
> + .device = uart_console_device,
> + .setup = sprd_console_setup,
> + .flags = CON_PRINTBUFFER,
> + .index = -1,
> + .data =&sprd_uart_driver,
> +};
> +
> +#define SPRD_CONSOLE (&sprd_console)
> +
> +/* Support for earlycon */
> +static void sprd_putc(struct uart_port *port, int c)
> +{
> + while (!(readl(port->membase + SPRD_LSR)& SPRD_LSR_TX_OVER))
> + ;
> + writeb(c, port->membase + SPRD_TXD);
> +}
> +
> +static void sprd_early_write(struct console *con, const char *s,
> + unsigned n)
> +{
> + struct earlycon_device *dev = con->data;
> +
> + uart_console_write(&dev->port, s, n, sprd_putc);
> +}
> +
> +static int __init sprd_early_console_setup(
> + struct earlycon_device *device,
> + const char *opt)
> +{
> + if (!device->port.membase)
> + return -ENODEV;
> +
> + device->con->write = sprd_early_write;
> + return 0;
> +}
> +
> +EARLYCON_DECLARE(sprd_serial, sprd_early_console_setup);
> +OF_EARLYCON_DECLARE(sprd_serial, "sprd,sc9836-uart",
> + sprd_early_console_setup);
> +
> +#else /* !CONFIG_SERIAL_SPRD_CONSOLE */
> +#define SPRD_CONSOLE NULL
> +#endif
> +
> +static struct uart_driver sprd_uart_driver = {
> + .owner = THIS_MODULE,
> + .driver_name = "sprd_serial",
> + .dev_name = SPRD_TTY_NAME,
> + .major = SPRD_TTY_MAJOR,
> + .minor = SPRD_TTY_MINOR_START,
> + .nr = UART_NR_MAX,
> + .cons = SPRD_CONSOLE,
> +};
> +
> +static int sprd_probe(struct platform_device *pdev)
> +{
> + struct resource *mem;
> + struct device_node *np = pdev->dev.of_node;
> + struct uart_port *up;
> + struct clk *clk;
> + int irq;
> +
> +
> + if (np)
> + pdev->id = of_alias_get_id(np, "serial");
> +
> + if (unlikely(pdev->id< 0 || pdev->id>= UART_NR_MAX)) {
> + dev_err(&pdev->dev, "does not support id %d\n", pdev->id);
> + return -ENXIO;
> + }
> +
> + sprd_port[pdev->id] = devm_kzalloc(&pdev->dev,
> + sizeof(*sprd_port[pdev->id]), GFP_KERNEL);
> + if (!sprd_port[pdev->id])
> + return -ENOMEM;
> +
> + up = (struct uart_port *)sprd_port[pdev->id];
> + up->dev =&pdev->dev;
> + up->line = pdev->id;
> + up->type = PORT_SPRD;
> + up->iotype = SERIAL_IO_PORT;
> + up->uartclk = SPRD_DEF_RATE;
> + up->fifosize = SPRD_FIFO_SIZE;
> + up->ops =&serial_sprd_ops;
> + up->flags = ASYNC_BOOT_AUTOCONF;
> +
> + clk = devm_clk_get(&pdev->dev, NULL);
> + if (!IS_ERR(clk))
> + up->uartclk = clk_get_rate(clk);
> +
> + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (unlikely(!mem)) {
> + dev_err(&pdev->dev, "not provide mem resource\n");
> + return -ENODEV;
> + }
> + up->mapbase = mem->start;
> + up->membase = ioremap(mem->start, resource_size(mem));
> +
> + irq = platform_get_irq(pdev, 0);
> + if (unlikely(irq< 0)) {
> + dev_err(&pdev->dev, "not provide irq resource\n");
> + return -ENODEV;
> + }
> + up->irq = irq;
> +
> + platform_set_drvdata(pdev, up);
> +
> + return uart_add_one_port(&sprd_uart_driver, up);
> +}
> +
> +static int sprd_remove(struct platform_device *dev)
> +{
> + struct uart_port *up = platform_get_drvdata(dev);
> +
> + return uart_remove_one_port(&sprd_uart_driver, up);
> +}
> +
> +static int sprd_suspend(struct platform_device *dev, pm_message_t state)
> +{
> + int id = dev->id;
> + struct uart_port *port = (struct uart_port *)sprd_port[id];
> + struct reg_backup *reg_bak =&(sprd_port[id]->reg_bak);
> +
> + reg_bak->ien = serial_in(port, SPRD_IEN);
> + reg_bak->ctrl0 = serial_in(port, SPRD_LCR);
> + reg_bak->ctrl1 = serial_in(port, SPRD_CTL1);
> + reg_bak->ctrl2 = serial_in(port, SPRD_CTL2);
> + reg_bak->clkd0 = serial_in(port, SPRD_CLKD0);
> + reg_bak->clkd1 = serial_in(port, SPRD_CLKD1);
> +
> + return 0;
> +}
> +
> +static int sprd_resume(struct platform_device *dev)
> +{
> + int id = dev->id;
> + struct uart_port *port = (struct uart_port *)sprd_port[id];
> + struct reg_backup *reg_bak =&(sprd_port[id]->reg_bak);
> +
> + serial_out(port, SPRD_LCR, reg_bak->ctrl0);
> + serial_out(port, SPRD_CTL1, reg_bak->ctrl1);
> + serial_out(port, SPRD_CTL2, reg_bak->ctrl2);
> + serial_out(port, SPRD_CLKD0, reg_bak->clkd0);
> + serial_out(port, SPRD_CLKD1, reg_bak->clkd1);
> + serial_out(port, SPRD_IEN, reg_bak->ien);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id serial_ids[] = {
> + {.compatible = "sprd,sc9836-uart",},
> + {}
> +};
> +
> +static struct platform_driver sprd_platform_driver = {
> + .probe = sprd_probe,
> + .remove = sprd_remove,
> + .suspend = sprd_suspend,
> + .resume = sprd_resume,
> + .driver = {
> + .name = "sprd_serial",
> + .owner = THIS_MODULE,
> + .of_match_table = of_match_ptr(serial_ids),
> + },
> +};
> +
> +static int __init sprd_serial_init(void)
> +{
> + int ret = 0;
> +
> + ret = uart_register_driver(&sprd_uart_driver);
> + if (unlikely(ret != 0))
> + return ret;
> +
> + ret = platform_driver_register(&sprd_platform_driver);
> + if (unlikely(ret != 0))
> + uart_unregister_driver(&sprd_uart_driver);
> +
> + return ret;
> +}
> +
> +static void __exit sprd_serial_exit(void)
> +{
> + platform_driver_unregister(&sprd_platform_driver);
> + uart_unregister_driver(&sprd_uart_driver);
> +}
> +
> +module_init(sprd_serial_init);
> +module_exit(sprd_serial_exit);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("Spreadtrum SoC serial driver series");
> diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
> index 16ad852..d9a8c88 100644
> --- a/include/uapi/linux/serial_core.h
> +++ b/include/uapi/linux/serial_core.h
> @@ -247,4 +247,7 @@
> /* MESON */
> #define PORT_MESON 109
>
> +/* SPRD SERIAL */
> +#define PORT_SPRD 110
> +
> #endif /* _UAPILINUX_SERIAL_CORE_H */

--
Murali Karicheri
Linux Kernel, Texas Instruments