[PATCH v6] serial:st-asc: Add ST ASC driver.

From: Srinivas KANDAGATLA
Date: Mon Jul 15 2013 - 07:48:58 EST

From: Srinivas Kandagatla <srinivas.kandagatla@xxxxxx>

This patch adds support to ASC (asynchronous serial controller)
driver, which is basically a standard serial driver. This IP is common
across all the ST parts for settop box platforms.

ASC is embedded in ST COMMS IP block. It supports Rx & Tx functionality.
It support all industry standard baud rates.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxx>
CC: Stephen Gallimore <stephen.gallimore@xxxxxx>
CC: Stuart Menefy <stuart.menefy@xxxxxx>
CC: Arnd Bergmann <arnd@xxxxxxxx>
CC: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---

Hi Greg,

This patch is the part of the driver support for Sti ARM SOCs.
This patch undergone 3-4 cycles of review in arm-kernel mailing list.
All the patches in that series went into 3.11.
This patch is based on 3.11-rc1.

Am resending this patch, as it missed 3.11 window.
Can you please consider this patch for 3.12.

Thanks,
srini

Changes since v5:
- Fixed build error reported by Greg when build without PINCTRL.

Changes since v4:
- rebased with tty-next branch from git.kernel.org tty repo.

Changes since v3:
- None.

Changes since v2:
- st-asc driver made POSIX compatible based on Russell K comment.

Changes since RFC:
- modified kconfig to remove default y
- removed all the forward declaration.
- use dynamic major numbering.
- merge header-file in to driver.

.../devicetree/bindings/tty/serial/st-asc.txt | 18 +
drivers/tty/serial/Kconfig | 15 +
drivers/tty/serial/Makefile | 1 +
drivers/tty/serial/st-asc.c | 937 ++++++++++++++++++++
include/uapi/linux/serial_core.h | 3 +
5 files changed, 974 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/tty/serial/st-asc.txt
create mode 100644 drivers/tty/serial/st-asc.c

diff --git a/Documentation/devicetree/bindings/tty/serial/st-asc.txt b/Documentation/devicetree/bindings/tty/serial/st-asc.txt
new file mode 100644
index 0000000..75d877f
--- /dev/null
+++ b/Documentation/devicetree/bindings/tty/serial/st-asc.txt
@@ -0,0 +1,18 @@
+*st-asc(Serial Port)
+
+Required properties:
+- compatible : Should be "st,asc".
+- reg, reg-names, interrupts, interrupt-names : Standard way to define device
+ resources with names. look in
+ Documentation/devicetree/bindings/resource-names.txt
+
+Optional properties:
+- st,hw-flow-ctrl bool flag to enable hardware flow control.
+- st,force-m1 bool flat to force asc to be in Mode-1 recommeded
+ for high bit rates (above 19.2K)
+Example:
+serial@fe440000{
+ compatible = "st,asc";
+ reg = <0xfe440000 0x2c>;
+ interrupts = <0 209 0>;
+};
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 5e3d689..bfca3bf 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1496,6 +1496,21 @@ config SERIAL_FSL_LPUART_CONSOLE
help
If you have enabled the lpuart serial port on the Freescale SoCs,
you can make it the console by answering Y to this option.
+config SERIAL_ST_ASC
+ tristate "ST ASC serial port support"
+ select SERIAL_CORE
+ help
+ This driver is for the on-chip Asychronous Serial Controller on
+ STMicroelectronics STi SoCs.
+ ASC is embedded in ST COMMS IP block. It supports Rx & Tx functionality.
+ It support all industry standard baud rates.
+
+ If unsure, say N.
+
+config SERIAL_ST_ASC_CONSOLE
+ bool "Support for console on ST ASC"
+ depends on SERIAL_ST_ASC=y
+ select SERIAL_CORE_CONSOLE

endmenu

diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
index cf650f0..47b679c 100644
--- a/drivers/tty/serial/Makefile
+++ b/drivers/tty/serial/Makefile
@@ -65,6 +65,7 @@ obj-$(CONFIG_SERIAL_KGDB_NMI) += kgdb_nmi.o
obj-$(CONFIG_SERIAL_KS8695) += serial_ks8695.o
obj-$(CONFIG_SERIAL_OMAP) += omap-serial.o
obj-$(CONFIG_SERIAL_ALTERA_UART) += altera_uart.o
+obj-$(CONFIG_SERIAL_ST_ASC) += st-asc.o
obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o
obj-$(CONFIG_SERIAL_QE) += ucc_uart.o
obj-$(CONFIG_SERIAL_TIMBERDALE) += timbuart.o
diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
new file mode 100644
index 0000000..1838798
--- /dev/null
+++ b/drivers/tty/serial/st-asc.c
@@ -0,0 +1,937 @@
+/*
+ * st-asc.c: ST Asynchronous serial controller (ASC) driver
+ *
+ * Copyright (C) 2003-2013 STMicroelectronics (R&D) Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#if defined(CONFIG_SERIAL_ST_ASC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
+#include <linux/module.h>
+#include <linux/serial.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/pm_runtime.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/serial_core.h>
+#include <linux/clk.h>
+
+#define DRIVER_NAME "st-asc"
+#define ASC_SERIAL_NAME "ttyAS"
+#define ASC_FIFO_SIZE 16
+#define ASC_MAX_PORTS 8
+
+struct asc_port {
+ struct uart_port port;
+ struct clk *clk;
+ unsigned int hw_flow_control:1;
+ unsigned int force_m1:1;
+};
+
+static struct asc_port asc_ports[ASC_MAX_PORTS];
+static struct uart_driver asc_uart_driver;
+
+/*---- UART Register definitions ------------------------------*/
+
+/* Register offsets */
+
+#define ASC_BAUDRATE 0x00
+#define ASC_TXBUF 0x04
+#define ASC_RXBUF 0x08
+#define ASC_CTL 0x0C
+#define ASC_INTEN 0x10
+#define ASC_STA 0x14
+#define ASC_GUARDTIME 0x18
+#define ASC_TIMEOUT 0x1C
+#define ASC_TXRESET 0x20
+#define ASC_RXRESET 0x24
+#define ASC_RETRIES 0x28
+
+/* ASC_RXBUF */
+#define ASC_RXBUF_PE 0x100
+#define ASC_RXBUF_FE 0x200
+/**
+ * Some of status comes from higher bits of the character and some come from
+ * the status register. Combining both of them in to single status using dummy
+ * bits.
+ */
+#define ASC_RXBUF_DUMMY_RX 0x10000
+#define ASC_RXBUF_DUMMY_BE 0x20000
+#define ASC_RXBUF_DUMMY_OE 0x40000
+
+/* ASC_CTL */
+
+#define ASC_CTL_MODE_MSK 0x0007
+#define ASC_CTL_MODE_8BIT 0x0001
+#define ASC_CTL_MODE_7BIT_PAR 0x0003
+#define ASC_CTL_MODE_9BIT 0x0004
+#define ASC_CTL_MODE_8BIT_WKUP 0x0005
+#define ASC_CTL_MODE_8BIT_PAR 0x0007
+#define ASC_CTL_STOP_MSK 0x0018
+#define ASC_CTL_STOP_HALFBIT 0x0000
+#define ASC_CTL_STOP_1BIT 0x0008
+#define ASC_CTL_STOP_1_HALFBIT 0x0010
+#define ASC_CTL_STOP_2BIT 0x0018
+#define ASC_CTL_PARITYODD 0x0020
+#define ASC_CTL_LOOPBACK 0x0040
+#define ASC_CTL_RUN 0x0080
+#define ASC_CTL_RXENABLE 0x0100
+#define ASC_CTL_SCENABLE 0x0200
+#define ASC_CTL_FIFOENABLE 0x0400
+#define ASC_CTL_CTSENABLE 0x0800
+#define ASC_CTL_BAUDMODE 0x1000
+
+/* ASC_GUARDTIME */
+
+#define ASC_GUARDTIME_MSK 0x00FF
+
+/* ASC_INTEN */
+
+#define ASC_INTEN_RBE 0x0001
+#define ASC_INTEN_TE 0x0002
+#define ASC_INTEN_THE 0x0004
+#define ASC_INTEN_PE 0x0008
+#define ASC_INTEN_FE 0x0010
+#define ASC_INTEN_OE 0x0020
+#define ASC_INTEN_TNE 0x0040
+#define ASC_INTEN_TOI 0x0080
+#define ASC_INTEN_RHF 0x0100
+
+/* ASC_RETRIES */
+
+#define ASC_RETRIES_MSK 0x00FF
+
+/* ASC_RXBUF */
+
+#define ASC_RXBUF_MSK 0x03FF
+
+/* ASC_STA */
+
+#define ASC_STA_RBF 0x0001
+#define ASC_STA_TE 0x0002
+#define ASC_STA_THE 0x0004
+#define ASC_STA_PE 0x0008
+#define ASC_STA_FE 0x0010
+#define ASC_STA_OE 0x0020
+#define ASC_STA_TNE 0x0040
+#define ASC_STA_TOI 0x0080
+#define ASC_STA_RHF 0x0100
+#define ASC_STA_TF 0x0200
+#define ASC_STA_NKD 0x0400
+
+/* ASC_TIMEOUT */
+
+#define ASC_TIMEOUT_MSK 0x00FF
+
+/* ASC_TXBUF */
+
+#define ASC_TXBUF_MSK 0x01FF
+
+/*---- Inline function definitions ---------------------------*/
+
+static inline struct asc_port *to_asc_port(struct uart_port *port)
+{
+ return container_of(port, struct asc_port, port);
+}
+
+static inline u32 asc_in(struct uart_port *port, u32 offset)
+{
+ return readl(port->membase + offset);
+}
+
+static inline void asc_out(struct uart_port *port, u32 offset, u32 value)
+{
+ writel(value, port->membase + offset);
+}
+
+/*
+ * Some simple utility functions to enable and disable interrupts.
+ * Note that these need to be called with interrupts disabled.
+ */
+static inline void asc_disable_tx_interrupts(struct uart_port *port)
+{
+ u32 intenable = asc_in(port, ASC_INTEN) & ~ASC_INTEN_THE;
+ asc_out(port, ASC_INTEN, intenable);
+ (void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */
+}
+
+static inline void asc_enable_tx_interrupts(struct uart_port *port)
+{
+ u32 intenable = asc_in(port, ASC_INTEN) | ASC_INTEN_THE;
+ asc_out(port, ASC_INTEN, intenable);
+}
+
+static inline void asc_disable_rx_interrupts(struct uart_port *port)
+{
+ u32 intenable = asc_in(port, ASC_INTEN) & ~ASC_INTEN_RBE;
+ asc_out(port, ASC_INTEN, intenable);
+ (void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */
+}
+
+static inline void asc_enable_rx_interrupts(struct uart_port *port)
+{
+ u32 intenable = asc_in(port, ASC_INTEN) | ASC_INTEN_RBE;
+ asc_out(port, ASC_INTEN, intenable);
+}
+
+static inline u32 asc_txfifo_is_empty(struct uart_port *port)
+{
+ return asc_in(port, ASC_STA) & ASC_STA_TE;
+}
+
+static inline int asc_txfifo_is_full(struct uart_port *port)
+{
+ return asc_in(port, ASC_STA) & ASC_STA_TF;
+}
+
+static inline const char *asc_port_name(struct uart_port *port)
+{
+ return to_platform_device(port->dev)->name;
+}
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * This section contains code to support the use of the ASC as a
+ * generic serial port.
+ */
+
+static inline unsigned asc_hw_txroom(struct uart_port *port)
+{
+ u32 status = asc_in(port, ASC_STA);
+
+ if (status & ASC_STA_THE)
+ return port->fifosize / 2;
+ else if (!(status & ASC_STA_TF))
+ return 1;
+
+ return 0;
+}
+
+/*
+ * Start transmitting chars.
+ * This is called from both interrupt and task level.
+ * Either way interrupts are disabled.
+ */
+static void asc_transmit_chars(struct uart_port *port)
+{
+ struct circ_buf *xmit = &port->state->xmit;
+ int txroom;
+ unsigned char c;
+
+ txroom = asc_hw_txroom(port);
+
+ if ((txroom != 0) && port->x_char) {
+ c = port->x_char;
+ port->x_char = 0;
+ asc_out(port, ASC_TXBUF, c);
+ port->icount.tx++;
+ txroom = asc_hw_txroom(port);
+ }
+
+ if (uart_tx_stopped(port)) {
+ /*
+ * We should try and stop the hardware here, but I
+ * don't think the ASC has any way to do that.
+ */
+ asc_disable_tx_interrupts(port);
+ return;
+ }
+
+ if (uart_circ_empty(xmit)) {
+ asc_disable_tx_interrupts(port);
+ return;
+ }
+
+ if (txroom == 0)
+ return;
+
+ do {
+ c = xmit->buf[xmit->tail];
+ xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+ asc_out(port, ASC_TXBUF, c);
+ port->icount.tx++;
+ txroom--;
+ } while ((txroom > 0) && (!uart_circ_empty(xmit)));
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(port);
+
+ if (uart_circ_empty(xmit))
+ asc_disable_tx_interrupts(port);
+}
+
+static void asc_receive_chars(struct uart_port *port)
+{
+ struct tty_port *tport = &port->state->port;
+ unsigned long status;
+ unsigned long c = 0;
+ char flag;
+
+ if (port->irq_wake)
+ pm_wakeup_event(tport->tty->dev, 0);
+
+ while ((status = asc_in(port, ASC_STA)) & ASC_STA_RBF) {
+ c = asc_in(port, ASC_RXBUF) | ASC_RXBUF_DUMMY_RX;
+ flag = TTY_NORMAL;
+ port->icount.rx++;
+
+ if ((c & (ASC_RXBUF_FE | ASC_RXBUF_PE)) ||
+ status & ASC_STA_OE) {
+
+ if (c & ASC_RXBUF_FE) {
+ if (c == ASC_RXBUF_FE) {
+ port->icount.brk++;
+ if (uart_handle_break(port))
+ continue;
+ c |= ASC_RXBUF_DUMMY_BE;
+ } else {
+ port->icount.frame++;
+ }
+ } else if (c & ASC_RXBUF_PE) {
+ port->icount.parity++;
+ }
+ /*
+ * Reading any data from the RX FIFO clears the
+ * overflow error condition.
+ */
+ if (status & ASC_STA_OE) {
+ port->icount.overrun++;
+ c |= ASC_RXBUF_DUMMY_OE;
+ }
+
+ c &= port->read_status_mask;
+
+ if (c & ASC_RXBUF_DUMMY_BE)
+ flag = TTY_BREAK;
+ else if (c & ASC_RXBUF_PE)
+ flag = TTY_PARITY;
+ else if (c & ASC_RXBUF_FE)
+ flag = TTY_FRAME;
+ }
+
+ if (uart_handle_sysrq_char(port, c))
+ continue;
+
+ uart_insert_char(port, c, ASC_RXBUF_DUMMY_OE, c & 0xff, flag);
+ }
+
+ /* Tell the rest of the system the news. New characters! */
+ tty_flip_buffer_push(tport);
+}
+
+static irqreturn_t asc_interrupt(int irq, void *ptr)
+{
+ struct uart_port *port = ptr;
+ u32 status;
+
+ spin_lock(&port->lock);
+
+ status = asc_in(port, ASC_STA);
+
+ if (status & ASC_STA_RBF) {
+ /* Receive FIFO not empty */
+ asc_receive_chars(port);
+ }
+
+ if ((status & ASC_STA_THE) &&
+ (asc_in(port, ASC_INTEN) & ASC_INTEN_THE)) {
+ /* Transmitter FIFO at least half empty */
+ asc_transmit_chars(port);
+ }
+
+ spin_unlock(&port->lock);
+
+ return IRQ_HANDLED;
+}
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * UART Functions
+ */
+
+static unsigned int asc_tx_empty(struct uart_port *port)
+{
+ return asc_txfifo_is_empty(port) ? TIOCSER_TEMT : 0;
+}
+
+static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+ /*
+ * This routine is used for seting signals of: DTR, DCD, CTS/RTS
+ * We use ASC's hardware for CTS/RTS, so don't need any for that.
+ * Some boards have DTR and DCD implemented using PIO pins,
+ * code to do this should be hooked in here.
+ */
+}
+
+static unsigned int asc_get_mctrl(struct uart_port *port)
+{
+ /*
+ * This routine is used for geting signals of: DTR, DCD, DSR, RI,
+ * and CTS/RTS
+ */
+ return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+}
+
+/* There are probably characters waiting to be transmitted. */
+static void asc_start_tx(struct uart_port *port)
+{
+ struct circ_buf *xmit = &port->state->xmit;
+
+ if (!uart_circ_empty(xmit))
+ asc_enable_tx_interrupts(port);
+}
+
+/* Transmit stop */
+static void asc_stop_tx(struct uart_port *port)
+{
+ asc_disable_tx_interrupts(port);
+}
+
+/* Receive stop */
+static void asc_stop_rx(struct uart_port *port)
+{
+ asc_disable_rx_interrupts(port);
+}
+
+/* Force modem status interrupts on */
+static void asc_enable_ms(struct uart_port *port)
+{
+ /* Nothing here yet .. */
+}
+
+/* Handle breaks - ignored by us */
+static void asc_break_ctl(struct uart_port *port, int break_state)
+{
+ /* Nothing here yet .. */
+}
+
+/*
+ * Enable port for reception.
+ */
+static int asc_startup(struct uart_port *port)
+{
+ if (request_irq(port->irq, asc_interrupt, IRQF_NO_SUSPEND,
+ asc_port_name(port), port)) {
+ dev_err(port->dev, "cannot allocate irq.\n");
+ return -ENODEV;
+ }
+
+ asc_transmit_chars(port);
+ asc_enable_rx_interrupts(port);
+
+ return 0;
+}
+
+static void asc_shutdown(struct uart_port *port)
+{
+ asc_disable_tx_interrupts(port);
+ asc_disable_rx_interrupts(port);
+ free_irq(port->irq, port);
+}
+
+static void asc_pm(struct uart_port *port, unsigned int state,
+ unsigned int oldstate)
+{
+ struct asc_port *ascport = to_asc_port(port);
+ unsigned long flags = 0;
+ u32 ctl;
+
+ switch (state) {
+ case UART_PM_STATE_ON:
+ clk_prepare_enable(ascport->clk);
+ break;
+ case UART_PM_STATE_OFF:
+ /*
+ * Disable the ASC baud rate generator, which is as close as
+ * we can come to turning it off. Note this is not called with
+ * the port spinlock held.
+ */
+ spin_lock_irqsave(&port->lock, flags);
+ ctl = asc_in(port, ASC_CTL) & ~ASC_CTL_RUN;
+ asc_out(port, ASC_CTL, ctl);
+ spin_unlock_irqrestore(&port->lock, flags);
+ clk_disable_unprepare(ascport->clk);
+ break;
+ }
+}
+
+static void asc_set_termios(struct uart_port *port, struct ktermios *termios,
+ struct ktermios *old)
+{
+ struct asc_port *ascport = to_asc_port(port);
+ unsigned int baud;
+ u32 ctrl_val;
+ tcflag_t cflag;
+ unsigned long flags;
+
+ /* Update termios to reflect hardware capabilities */
+ termios->c_cflag &= ~(CMSPAR |
+ (ascport->hw_flow_control ? 0 : CRTSCTS));
+
+ port->uartclk = clk_get_rate(ascport->clk);
+
+ baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
+ cflag = termios->c_cflag;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ /* read control register */
+ ctrl_val = asc_in(port, ASC_CTL);
+
+ /* stop serial port and reset value */
+ asc_out(port, ASC_CTL, (ctrl_val & ~ASC_CTL_RUN));
+ ctrl_val = ASC_CTL_RXENABLE | ASC_CTL_FIFOENABLE;
+
+ /* reset fifo rx & tx */
+ asc_out(port, ASC_TXRESET, 1);
+ asc_out(port, ASC_RXRESET, 1);
+
+ /* set character length */
+ if ((cflag & CSIZE) == CS7) {
+ ctrl_val |= ASC_CTL_MODE_7BIT_PAR;
+ } else {
+ ctrl_val |= (cflag & PARENB) ? ASC_CTL_MODE_8BIT_PAR :
+ ASC_CTL_MODE_8BIT;
+ }
+
+ /* set stop bit */
+ ctrl_val |= (cflag & CSTOPB) ? ASC_CTL_STOP_2BIT : ASC_CTL_STOP_1BIT;
+
+ /* odd parity */
+ if (cflag & PARODD)
+ ctrl_val |= ASC_CTL_PARITYODD;
+
+ /* hardware flow control */
+ if ((cflag & CRTSCTS))
+ ctrl_val |= ASC_CTL_CTSENABLE;
+
+ if ((baud < 19200) && !ascport->force_m1) {
+ asc_out(port, ASC_BAUDRATE, (port->uartclk / (16 * baud)));
+ } else {
+ /*
+ * MODE 1: recommended for high bit rates (above 19.2K)
+ *
+ * baudrate * 16 * 2^16
+ * ASCBaudRate = ------------------------
+ * inputclock
+ *
+ * However to keep the maths inside 32bits we divide top and
+ * bottom by 64. The +1 is to avoid a divide by zero if the
+ * input clock rate is something unexpected.
+ */
+ u32 counter = (baud * 16384) / ((port->uartclk / 64) + 1);
+ asc_out(port, ASC_BAUDRATE, counter);
+ ctrl_val |= ASC_CTL_BAUDMODE;
+ }
+
+ uart_update_timeout(port, cflag, baud);
+
+ ascport->port.read_status_mask = ASC_RXBUF_DUMMY_OE;
+ if (termios->c_iflag & INPCK)
+ ascport->port.read_status_mask |= ASC_RXBUF_FE | ASC_RXBUF_PE;
+ if (termios->c_iflag & (BRKINT | PARMRK))
+ ascport->port.read_status_mask |= ASC_RXBUF_DUMMY_BE;
+
+ /*
+ * Characters to ignore
+ */
+ ascport->port.ignore_status_mask = 0;
+ if (termios->c_iflag & IGNPAR)
+ ascport->port.ignore_status_mask |= ASC_RXBUF_FE | ASC_RXBUF_PE;
+ if (termios->c_iflag & IGNBRK) {
+ ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_BE;
+ /*
+ * If we're ignoring parity and break indicators,
+ * ignore overruns too (for real raw support).
+ */
+ if (termios->c_iflag & IGNPAR)
+ ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_OE;
+ }
+
+ /*
+ * Ignore all characters if CREAD is not set.
+ */
+ if (!(termios->c_cflag & CREAD))
+ ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_RX;
+
+ /* Set the timeout */
+ asc_out(port, ASC_TIMEOUT, 20);
+
+ /* write final value and enable port */
+ asc_out(port, ASC_CTL, (ctrl_val | ASC_CTL_RUN));
+
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *asc_type(struct uart_port *port)
+{
+ return (port->type == PORT_ASC) ? DRIVER_NAME : NULL;
+}
+
+static void asc_release_port(struct uart_port *port)
+{
+}
+
+static int asc_request_port(struct uart_port *port)
+{
+ return 0;
+}
+
+/*
+ * Called when the port is opened, and UPF_BOOT_AUTOCONF flag is set
+ * Set type field if successful
+ */
+static void asc_config_port(struct uart_port *port, int flags)
+{
+ if ((flags & UART_CONFIG_TYPE))
+ port->type = PORT_ASC;
+}
+
+static int
+asc_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+ /* No user changeable parameters */
+ return -EINVAL;
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+/*
+ * Console polling routines for writing and reading from the uart while
+ * in an interrupt or debug context (i.e. kgdb).
+ */
+
+static int asc_get_poll_char(struct uart_port *port)
+{
+ if (!(asc_in(port, ASC_STA) & ASC_STA_RBF))
+ return NO_POLL_CHAR;
+
+ return asc_in(port, ASC_RXBUF);
+}
+
+static void asc_put_poll_char(struct uart_port *port, unsigned char c)
+{
+ while (asc_txfifo_is_full(port))
+ cpu_relax();
+ asc_out(port, ASC_TXBUF, c);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
+/*---------------------------------------------------------------------*/
+
+static struct uart_ops asc_uart_ops = {
+ .tx_empty = asc_tx_empty,
+ .set_mctrl = asc_set_mctrl,
+ .get_mctrl = asc_get_mctrl,
+ .start_tx = asc_start_tx,
+ .stop_tx = asc_stop_tx,
+ .stop_rx = asc_stop_rx,
+ .enable_ms = asc_enable_ms,
+ .break_ctl = asc_break_ctl,
+ .startup = asc_startup,
+ .shutdown = asc_shutdown,
+ .set_termios = asc_set_termios,
+ .type = asc_type,
+ .release_port = asc_release_port,
+ .request_port = asc_request_port,
+ .config_port = asc_config_port,
+ .verify_port = asc_verify_port,
+ .pm = asc_pm,
+#ifdef CONFIG_CONSOLE_POLL
+ .poll_get_char = asc_get_poll_char,
+ .poll_put_char = asc_put_poll_char,
+#endif /* CONFIG_CONSOLE_POLL */
+};
+
+static int asc_init_port(struct asc_port *ascport,
+ struct platform_device *pdev)
+{
+ struct uart_port *port = &ascport->port;
+ struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+ if (!res) {
+ dev_err(&pdev->dev, "Unable to get io resource\n");
+ return -ENODEV;
+ }
+
+ port->iotype = UPIO_MEM;
+ port->flags = UPF_BOOT_AUTOCONF;
+ port->ops = &asc_uart_ops;
+ port->fifosize = ASC_FIFO_SIZE;
+ port->dev = &pdev->dev;
+ port->mapbase = res->start;
+ port->irq = platform_get_irq(pdev, 0);
+
+ port->membase = devm_request_and_ioremap(&pdev->dev, res);
+ if (!port->membase) {
+ dev_err(&pdev->dev, "Unable to request io memory\n");
+ return -ENODEV;
+ }
+
+ spin_lock_init(&port->lock);
+
+ ascport->clk = devm_clk_get(&pdev->dev, NULL);
+
+ if (WARN_ON(IS_ERR(ascport->clk)))
+ return -EINVAL;
+ /* ensure that clk rate is correct by enabling the clk */
+ clk_prepare_enable(ascport->clk);
+ ascport->port.uartclk = clk_get_rate(ascport->clk);
+ WARN_ON(ascport->port.uartclk == 0);
+ clk_disable_unprepare(ascport->clk);
+
+ return 0;
+}
+
+static struct asc_port *asc_of_get_asc_port(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ int id;
+
+ if (!np)
+ return NULL;
+
+ id = of_alias_get_id(np, ASC_SERIAL_NAME);
+
+ if (id < 0)
+ id = 0;
+
+ if (WARN_ON(id >= ASC_MAX_PORTS))
+ return NULL;
+
+ asc_ports[id].hw_flow_control = of_property_read_bool(np,
+ "st,hw-flow-control");
+ asc_ports[id].force_m1 = of_property_read_bool(np, "st,force_m1");
+ asc_ports[id].port.line = id;
+ return &asc_ports[id];
+}
+
+static struct of_device_id asc_match[] = {
+ { .compatible = "st,asc", },
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, asc_match);
+
+static int asc_serial_probe(struct platform_device *pdev)
+{
+ int ret;
+ struct asc_port *ascport;
+
+ ascport = asc_of_get_asc_port(pdev);
+ if (!ascport)
+ return -ENODEV;
+
+ ret = asc_init_port(ascport, pdev);
+ if (ret)
+ return ret;
+
+ ret = uart_add_one_port(&asc_uart_driver, &ascport->port);
+ if (ret)
+ return ret;
+
+ platform_set_drvdata(pdev, &ascport->port);
+
+ return 0;
+}
+
+static int asc_serial_remove(struct platform_device *pdev)
+{
+ struct uart_port *port = platform_get_drvdata(pdev);
+
+ platform_set_drvdata(pdev, NULL);
+ return uart_remove_one_port(&asc_uart_driver, port);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int asc_serial_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct uart_port *port = platform_get_drvdata(pdev);
+
+ return uart_suspend_port(&asc_uart_driver, port);
+}
+
+static int asc_serial_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct uart_port *port = platform_get_drvdata(pdev);
+
+ return uart_resume_port(&asc_uart_driver, port);
+}
+
+#endif /* CONFIG_PM_SLEEP */
+
+/*----------------------------------------------------------------------*/
+
+#ifdef CONFIG_SERIAL_ST_ASC_CONSOLE
+static void asc_console_putchar(struct uart_port *port, int ch)
+{
+ unsigned int timeout = 1000000;
+
+ /* Wait for upto 1 second in case flow control is stopping us. */
+ while (--timeout && asc_txfifo_is_full(port))
+ udelay(1);
+
+ asc_out(port, ASC_TXBUF, ch);
+}
+
+/*
+ * Print a string to the serial port trying not to disturb
+ * any possible real use of the port...
+ */
+
+static void asc_console_write(struct console *co, const char *s, unsigned count)
+{
+ struct uart_port *port = &asc_ports[co->index].port;
+ unsigned long flags;
+ unsigned long timeout = 1000000;
+ int locked = 1;
+ u32 intenable;
+
+ local_irq_save(flags);
+ if (port->sysrq)
+ locked = 0; /* asc_interrupt has already claimed the lock */
+ else if (oops_in_progress)
+ locked = spin_trylock(&port->lock);
+ else
+ spin_lock(&port->lock);
+
+ /*
+ * Disable interrupts so we don't get the IRQ line bouncing
+ * up and down while interrupts are disabled.
+ */
+ intenable = asc_in(port, ASC_INTEN);
+ asc_out(port, ASC_INTEN, 0);
+ (void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */
+
+ uart_console_write(port, s, count, asc_console_putchar);
+
+ while (--timeout && !asc_txfifo_is_empty(port))
+ udelay(1);
+
+ asc_out(port, ASC_INTEN, intenable);
+
+ if (locked)
+ spin_unlock(&port->lock);
+ local_irq_restore(flags);
+}
+
+static int asc_console_setup(struct console *co, char *options)
+{
+ struct asc_port *ascport;
+ int baud = 9600;
+ int bits = 8;
+ int parity = 'n';
+ int flow = 'n';
+
+ if (co->index >= ASC_MAX_PORTS)
+ return -ENODEV;
+
+ ascport = &asc_ports[co->index];
+
+ /*
+ * This driver does not support early console initialization
+ * (use ARM early printk support instead), so we only expect
+ * this to be called during the uart port registration when the
+ * driver gets probed and the port should be mapped at that point.
+ */
+ BUG_ON(ascport->port.mapbase == 0 || ascport->port.membase == NULL);
+
+ if (options)
+ uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+ return uart_set_options(&ascport->port, co, baud, parity, bits, flow);
+}
+
+static struct console asc_console = {
+ .name = ASC_SERIAL_NAME,
+ .device = uart_console_device,
+ .write = asc_console_write,
+ .setup = asc_console_setup,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+ .data = &asc_uart_driver,
+};
+
+#define ASC_SERIAL_CONSOLE (&asc_console)
+
+#else
+#define ASC_SERIAL_CONSOLE NULL
+#endif /* CONFIG_SERIAL_ST_ASC_CONSOLE */
+
+static struct uart_driver asc_uart_driver = {
+ .owner = THIS_MODULE,
+ .driver_name = DRIVER_NAME,
+ .dev_name = ASC_SERIAL_NAME,
+ .major = 0,
+ .minor = 0,
+ .nr = ASC_MAX_PORTS,
+ .cons = ASC_SERIAL_CONSOLE,
+};
+
+static const struct dev_pm_ops asc_serial_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(asc_serial_suspend, asc_serial_resume)
+};
+
+static struct platform_driver asc_serial_driver = {
+ .probe = asc_serial_probe,
+ .remove = asc_serial_remove,
+ .driver = {
+ .name = DRIVER_NAME,
+ .pm = &asc_serial_pm_ops,
+ .owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(asc_match),
+ },
+};
+
+static int __init asc_init(void)
+{
+ int ret;
+ static char banner[] __initdata =
+ KERN_INFO "STMicroelectronics ASC driver initialized\n";
+
+ printk(banner);
+
+ ret = uart_register_driver(&asc_uart_driver);
+ if (ret)
+ return ret;
+
+ ret = platform_driver_register(&asc_serial_driver);
+ if (ret)
+ uart_unregister_driver(&asc_uart_driver);
+
+ return ret;
+}
+
+static void __exit asc_exit(void)
+{
+ platform_driver_unregister(&asc_serial_driver);
+ uart_unregister_driver(&asc_uart_driver);
+}
+
+module_init(asc_init);
+module_exit(asc_exit);
+
+MODULE_ALIAS("platform:" DRIVER_NAME);
+MODULE_AUTHOR("STMicroelectronics (R&D) Limited");
+MODULE_DESCRIPTION("STMicroelectronics ASC serial port driver");
+MODULE_LICENSE("GPL");
diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
index 9119cc0..e40ebe1 100644
--- a/include/uapi/linux/serial_core.h
+++ b/include/uapi/linux/serial_core.h
@@ -232,4 +232,7 @@
/* SH-SCI */
#define PORT_HSCIF 104

+/* ST ASC type numbers */
+#define PORT_ASC 105
+
#endif /* _UAPILINUX_SERIAL_CORE_H */
--
1.7.6.5

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