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

From: Murali Karicheri
Date: Wed Nov 26 2014 - 13:31:47 EST

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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@xxxxxxxxxxxxxx>
Signed-off-by: Orson Zhai<orson.zhai@xxxxxxxxxxxxxx>
Originally-by: Lanqing Liu<lanqing.liu@xxxxxxxxxxxxxx>
---
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

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