[PATCH] max3100 driver

Christian Pellegrin
2008-09-20T07:20:14Z

This patch adds support for the MAX3100 SPI UART.

Generated on 20080920 against v2.6.27-rc6

Signed-off-by: Christian Pellegrin <chripell@fsfe.org>
---
drivers/serial/Kconfig | 6 +-
drivers/serial/Makefile | 1 +
drivers/serial/max3100.c | 976 ++++++++++++++++++++++++++++++++++++++++
include/linux/serial_core.h | 3 +
include/linux/serial_max3100.h | 31 ++
5 files changed, 1016 insertions(+), 1 deletions(-)

diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 77cb342..de3193d 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -509,7 +509,11 @@ config SERIAL_S3C2440
help
Serial port support for the Samsung S3C2440 and S3C2442 SoC

-
+config SERIAL_MAX3100
+ tristate "MAX3100 support"
+ depends on SPI
+ help
+ MAX3100 chip support

config SERIAL_DZ
bool "DECstation DZ serial driver"
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index 7e7383e..21c3daf 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -31,6 +31,7 @@ obj-$(CONFIG_SERIAL_S3C2400) += s3c2400.o
obj-$(CONFIG_SERIAL_S3C2410) += s3c2410.o
obj-$(CONFIG_SERIAL_S3C2412) += s3c2412.o
obj-$(CONFIG_SERIAL_S3C2440) += s3c2440.o
+obj-$(CONFIG_SERIAL_MAX3100) += max3100.o
obj-$(CONFIG_SERIAL_SUNCORE) += suncore.o
obj-$(CONFIG_SERIAL_SUNHV) += sunhv.o
obj-$(CONFIG_SERIAL_SUNZILOG) += sunzilog.o
diff --git a/drivers/serial/max3100.c b/drivers/serial/max3100.c
new file mode 100644
index 0000000..f8a8af1
--- /dev/null
+++ b/drivers/serial/max3100.c
@@ -0,0 +1,976 @@
+/*
+ *
+ * Copyright (C) 2008 Christian Pellegrin <chripell@evolware.org>
+ *
+ * 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.
+ *
+ *
+ * Notes: the MAX3100 doesn't provide an interrupt on CTS so we have
+ * to use polling for flow control. TX empty IRQ is unusable, since
+ * writing conf clears FIFO buffer and we cannot have this interrupt
+ * always asking us for attention.
+ *
+ * Example platform data:
+
+static struct plat_max3100 max3100_plat_data = {
+ .loopback = 0,
+ .crystal = 0,
+ .only_edge_irq = 0,
+ .poll_time = 100,
+};
+
+static struct spi_board_info spi_board_info[] = {
+ {
+ .modalias = "max3100",
+ .platform_data = &max3100_plat_data,
+ .irq = IRQ_EINT12,
+ .max_speed_hz = 5*1000*1000,
+ .chip_select = 0,
+ },
+};
+
+ * The initial minor number is 128 in the low-density serial port:
+ * mknod /dev/ttyMAX0 c 204 128
+ */
+
+#define MAX3100_MAJOR 204
+#define MAX3100_MINOR 128
+/* 4 MAX3100s should be enough for everyone */
+#define MAX_MAX3100 4
+
+#include <linux/bitops.h>
+#include <linux/console.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/fcntl.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/keyboard.h>
+#include <linux/major.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/pm.h>
+#include <linux/reboot.h>
+#include <linux/sched.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/signal.h>
+#include <linux/spi/spi.h>
+#include <linux/string.h>
+#include <linux/timer.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/uaccess.h>
+#include <linux/workqueue.h>
+#include <linux/freezer.h>
+
+#include <asm/system.h>
+
+#include <linux/serial_max3100.h>
+
+#define MAX3100_C (1<<14)
+#define MAX3100_D (0<<14)
+#define MAX3100_W (1<<15)
+#define MAX3100_RX (0<<15)
+
+#define MAX3100_WC (MAX3100_W | MAX3100_C)
+#define MAX3100_RC (MAX3100_RX | MAX3100_C)
+#define MAX3100_WD (MAX3100_W | MAX3100_D)
+#define MAX3100_RD (MAX3100_RX | MAX3100_D)
+#define MAX3100_CMD (3 << 14)
+
+#define MAX3100_T (1<<14)
+#define MAX3100_R (1<<15)
+
+#define MAX3100_FEN (1<<13)
+#define MAX3100_SHDN (1<<12)
+#define MAX3100_TM (1<<11)
+#define MAX3100_RM (1<<10)
+#define MAX3100_PM (1<<9)
+#define MAX3100_RAM (1<<8)
+#define MAX3100_IR (1<<7)
+#define MAX3100_ST (1<<6)
+#define MAX3100_PE (1<<5)
+#define MAX3100_L (1<<4)
+#define MAX3100_BAUD (0xf)
+
+#define MAX3100_TE (1<<10)
+#define MAX3100_RAFE (1<<10)
+#define MAX3100_RTS (1<<9)
+#define MAX3100_CTS (1<<9)
+#define MAX3100_PT (1<<8)
+#define MAX3100_DATA (0xff)
+
+#define MAX3100_RT (MAX3100_R | MAX3100_T)
+#define MAX3100_RTC (MAX3100_RT | MAX3100_CTS | MAX3100_RAFE)
+
+/* the following simulate a status reg for ignore_status_mask */
+#define MAX3100_STATUS_PE 1
+#define MAX3100_STATUS_FE 2
+#define MAX3100_STATUS_OE 4
+
+struct max3100_port_s {
+ struct uart_port port;
+ struct spi_device *spi;
+
+ int cts:1; /* last CTS received for flow ctrl */
+ int tx_empty:1; /* last TX empty bit */
+
+ spinlock_t conf_lock; /* shared data */
+ int conf_commit:1; /* need to make changes */
+ int conf; /* configuration for the MAX31000
+ * (bits 0-7, bits 8-11 are irqs) */
+ int rts_commit:1; /* need to change rts */
+ int rts:1; /* rts status */
+
+ int parity:3; /* keeps track if we should send parity */
+#define MAX3100_PARITY_ON 1
+#define MAX3100_PARITY_ODD 2
+#define MAX3100_7BIT 4
+ int rx_enabled:1; /* if we should rx chars */
+
+ int irq; /* irq assigned to the max3100 */
+
+ int minor; /* minor number */
+ int crystal:1; /* 1 if 3.6864Mhz crystal 0 for 1.8432 */
+ int loopback:1; /* 1 if we are in loopback mode */
+ int only_edge_irq:1; /* 1 if we have only edge irqs (like PXA) */
+
+ /* for handling irqs: need workqueue since we do spi_sync */
+ struct workqueue_struct *workqueue;
+ struct work_struct work;
+ /* set to 1 to make the workhandler exit as soon as possible */
+ int force_end_work:1;
+ /* need to know we are suspending to avoid deadlock on workqueue */
+ int suspending:1;
+
+ /* these are for IRQ on/off counting */
+ int irq_status;
+ /* avoid race condition on irq_status */
+ spinlock_t irq_lock;
+
+ /* hook for suspending MAX3100 via dedicated pin */
+ void (*max3100_hw_suspend) (int suspend);
+
+ /* poll time (in ms) for ctrl lines */
+ int poll_time;
+ /* and it's timer */
+ struct timer_list timer;
+};
+
+static struct max3100_port_s *max3100s[MAX_MAX3100]; /* the chips */
+
+static void irq_state(struct max3100_port_s *s, int on)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&s->irq_lock, flags);
+ if (s->irq_status != on) {
+ if (on)
+ enable_irq(s->irq);
+ else
+ disable_irq(s->irq);
+ s->irq_status = on;
+ }
+ spin_unlock_irqrestore(&s->irq_lock, flags);
+}
+
+static int max3100_do_parity(struct max3100_port_s *s, u16 c)
+{
+ int parity;
+ int i, n;
+
+ if (s->parity & MAX3100_PARITY_ODD)
+ parity = 0;
+ else
+ parity = 1;
+
+ if (s->parity & MAX3100_7BIT)
+ n = 7;
+ else
+ n = 8;
+
+ for (i = 0; i < n; i++)
+ parity = parity ^ ((c>>i) & 1);
+ return parity;
+}
+
+static int max3100_check_parity(struct max3100_port_s *s, u16 c)
+{
+ return max3100_do_parity(s, c) ==
+ ((c >> (s->parity & MAX3100_7BIT ? 7 : 8)) & 1);
+}
+
+static void max3100_calc_parity(struct max3100_port_s *s, u16 *c)
+{
+ *c &= ~MAX3100_PT;
+ if (s->parity & MAX3100_PARITY_ON)
+ *c |= max3100_do_parity(s, *c)<<8;
+}
+
+static void max3100_work(struct work_struct *w);
+
+static void max3100_dowork(struct max3100_port_s *s)
+{
+ if (!s->force_end_work && !work_pending(&s->work)) {
+ PREPARE_WORK(&s->work, max3100_work);
+ queue_work(s->workqueue, &s->work);
+ }
+}
+
+static void max3100_timeout(unsigned long data)
+{
+ struct max3100_port_s *s = (struct max3100_port_s *)data;
+
+ if (s->port.info) {
+ max3100_dowork(s);
+ mod_timer(&s->timer, jiffies + s->poll_time);
+ }
+}
+
+static int max3100_sr(struct max3100_port_s *s, u16 tx, u16 *rx)
+{
+ struct spi_message message;
+ struct spi_transfer tran;
+ u16 etx, erx;
+ int status;
+
+ etx = htons(tx);
+ spi_message_init(&message);
+ memset(&tran, 0, sizeof(tran));
+ tran.tx_buf = &etx;
+ tran.rx_buf = &erx;
+ tran.len = 2;
+ spi_message_add_tail(&tran, &message);
+ status = spi_sync(s->spi, &message);
+ if (status) {
+ dev_warn(&s->spi->dev, "error while calling spi_sync\n");
+ return -EIO;
+ }
+ *rx = ntohs(erx);
+ s->tx_empty = (*rx & MAX3100_T) > 0;
+ dev_dbg(&s->spi->dev, "%04x - %04x\n", tx, *rx);
+ return 0;
+}
+
+static int max3100_handlerx(struct max3100_port_s *s, u16 rx)
+{
+ unsigned int ch, flg, status = 0;
+ int ret = 0, cts;
+
+ if (rx & MAX3100_R && s->rx_enabled) {
+ dev_dbg(&s->spi->dev, "%s\n", __func__);
+ ch = rx & (s->parity & MAX3100_7BIT ? 0x7f : 0xff);
+ if (rx & MAX3100_RAFE) {
+ s->port.icount.frame++;
+ flg = TTY_FRAME;
+ status |= MAX3100_STATUS_FE;
+ } else {
+ if (s->parity & MAX3100_PARITY_ON) {
+ if (max3100_check_parity(s, rx)) {
+ s->port.icount.rx++;
+ flg = TTY_NORMAL;
+ } else {
+ s->port.icount.parity++;
+ flg = TTY_PARITY;
+ status |= MAX3100_STATUS_PE;
+ }
+ } else {
+ s->port.icount.rx++;
+ flg = TTY_NORMAL;
+ }
+ }
+ uart_insert_char(&s->port, status, MAX3100_STATUS_OE, ch, flg);
+ ret = 1;
+ }
+
+ cts = (rx & MAX3100_CTS) > 0;
+ if (s->cts != cts) {
+ s->cts = cts;
+ uart_handle_cts_change(&s->port, cts ? TIOCM_CTS : 0);
+ }
+
+ return ret;
+}
+
+static void max3100_work(struct work_struct *w)
+{
+ struct max3100_port_s *s = container_of(w, struct max3100_port_s, work);
+ int rxchars;
+ u16 tx, rx;
+ int conf, cconf, rts, crts;
+ struct circ_buf *xmit = &s->port.info->xmit;
+
+ dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+ do {
+ rxchars = 0;
+
+ spin_lock(&s->conf_lock);
+ conf = s->conf;
+ cconf = s->conf_commit;
+ s->conf_commit = 0;
+ rts = s->rts;
+ crts = s->rts_commit;
+ s->rts_commit = 0;
+ spin_unlock(&s->conf_lock);
+ if (cconf)
+ max3100_sr(s, MAX3100_WC | conf, &rx);
+ if (crts) {
+ max3100_sr(s, MAX3100_WD | MAX3100_TE |
+ (s->rts ? MAX3100_RTS : 0), &rx);
+ rxchars += max3100_handlerx(s, rx);
+ }
+
+ max3100_sr(s, MAX3100_RD, &rx);
+ rxchars += max3100_handlerx(s, rx);
+
+ if (rx & MAX3100_T) {
+ tx = 0xffff;
+ if (s->port.x_char) {
+ tx = s->port.x_char;
+ s->port.icount.tx++;
+ s->port.x_char = 0;
+ } else if (!uart_circ_empty(xmit) &&
+ !uart_tx_stopped(&s->port)) {
+ tx = xmit->buf[xmit->tail];
+ xmit->tail = (xmit->tail + 1) &
+ (UART_XMIT_SIZE - 1);
+ s->port.icount.tx++;
+ }
+ if (tx != 0xffff) {
+ max3100_calc_parity(s, &tx);
+ tx |= MAX3100_WD | (s->rts ? MAX3100_RTS : 0);
+ max3100_sr(s, tx, &rx);
+ rxchars += max3100_handlerx(s, rx);
+ }
+ }
+
+ if (rxchars > 0)
+ tty_flip_buffer_push(s->port.info->port.tty);
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(&s->port);
+
+ } while (!s->force_end_work &&
+ !freezing(current) &&
+ ((rx & MAX3100_R) ||
+ (!uart_circ_empty(xmit) &&
+ !uart_tx_stopped(&s->port))));
+
+ if (!s->only_edge_irq && !s->force_end_work &&
+ !freezing(current))
+ irq_state(s, 1);
+}
+
+static irqreturn_t max3100_irq(int irqno, void *dev_id)
+{
+ struct max3100_port_s *s = dev_id;
+
+ dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+ if (!s->only_edge_irq)
+ irq_state(s, 0); /* avoid irq storm */
+ max3100_dowork(s);
+ return IRQ_HANDLED;
+}
+
+static void max3100_enable_ms(struct uart_port *port)
+{
+ struct max3100_port_s *s = container_of(port,
+ struct max3100_port_s,
+ port);
+
+ if (s->poll_time > 0)
+ mod_timer(&s->timer, jiffies);
+ dev_dbg(&s->spi->dev, "%s\n", __func__);
+}
+
+static void max3100_start_tx(struct uart_port *port)
+{
+ struct max3100_port_s *s = container_of(port,
+ struct max3100_port_s,
+ port);
+
+ dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+ max3100_dowork(s);
+}
+
+static void max3100_stop_rx(struct uart_port *port)
+{
+ struct max3100_port_s *s = container_of(port,
+ struct max3100_port_s,
+ port);
+
+ dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+ s->rx_enabled = 0;
+ spin_lock(&s->conf_lock);
+ s->conf &= ~MAX3100_RM;
+ s->conf_commit = 1;
+ spin_unlock(&s->conf_lock);
+ max3100_dowork(s);
+}
+
+static unsigned int max3100_tx_empty(struct uart_port *port)
+{
+ struct max3100_port_s *s = container_of(port,
+ struct max3100_port_s,
+ port);
+
+ dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+ /* may not be truely up-to-date */
+ max3100_dowork(s);
+ return s->tx_empty;
+}
+
+static unsigned int max3100_get_mctrl(struct uart_port *port)
+{
+ struct max3100_port_s *s = container_of(port,
+ struct max3100_port_s,
+ port);
+
+ dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+ /* may not be truely up-to-date */
+ max3100_dowork(s);
+ /* always assert DCD and DSR since these lines are not wired */
+ return (s->cts ? TIOCM_CTS : 0) | TIOCM_DSR | TIOCM_CAR;
+}
+
+static void max3100_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+ struct max3100_port_s *s = container_of(port,
+ struct max3100_port_s,
+ port);
+ int rts;
+
+ dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+ rts = (mctrl & TIOCM_RTS) > 0;
+
+ spin_lock(&s->conf_lock);
+ if (s->rts != rts) {
+ s->rts = rts;
+ s->rts_commit = 1;
+ max3100_dowork(s);
+ }
+ spin_unlock(&s->conf_lock);
+}
+
+static void
+max3100_set_termios(struct uart_port *port, struct ktermios *termios,
+ struct ktermios *old)
+{
+ struct max3100_port_s *s = container_of(port,
+ struct max3100_port_s,
+ port);
+ int baud = 0;
+
+ dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+ if (!old || (termios->c_cflag != old->c_cflag)) {
+ unsigned cflag;
+ unsigned i;
+ u32 param_new;
+ u32 param_mask;
+ u32 parity = 0;
+
+ cflag = termios->c_cflag;
+ param_new = 0;
+ param_mask = 0;
+
+ i = cflag & CBAUD;
+ switch (i) {
+ case B300:
+ if (s->crystal) {
+ param_new = 16;
+ } else {
+ dev_warn(&s->spi->dev,
+ "unsupported baud rate!\n");
+ param_new = 15;
+ }
+ baud = 300;
+ break;
+ case B600:
+ param_new = 15;
+ baud = 600;
+ break;
+ case B1200:
+ param_new = 14;
+ baud = 1200;
+ break;
+ case B2400:
+ param_new = 13;
+ baud = 2400;
+ break;
+ case B4800:
+ param_new = 12;
+ baud = 4800;
+ break;
+ case B9600:
+ param_new = 11;
+ baud = 9600;
+ break;
+ case B19200:
+ param_new = 10;
+ baud = 19200;
+ break;
+ case B38400:
+ param_new = 9;
+ baud = 38400;
+ break;
+ case B57600:
+ param_new = 2;
+ baud = 57600;
+ break;
+ case B115200:
+ param_new = 1;
+ baud = 11520;
+ break;
+ case B230400:
+ if (s->crystal) {
+ param_new = 1;
+ dev_warn(&s->spi->dev,
+ "unsupported baud rate!\n");
+ } else {
+ param_new = 0;
+ }
+ baud = 230400;
+ break;
+ default:
+ param_new = 1;
+ dev_warn(&s->spi->dev, "invalid baudrate\n");
+ }
+ param_new = (param_new - s->crystal) & MAX3100_BAUD;
+ param_mask |= MAX3100_BAUD;
+
+ if ((cflag & CSIZE) == CS8) {
+ param_new &= ~MAX3100_L;
+ parity &= ~MAX3100_7BIT;
+ } else {
+ param_new |= MAX3100_L;
+ parity |= MAX3100_7BIT;
+ }
+ param_mask |= MAX3100_L;
+
+ if (cflag & CSTOPB)
+ param_new |= MAX3100_ST;
+ else
+ param_new &= ~MAX3100_ST;
+ param_mask |= MAX3100_ST;
+
+ if (cflag & PARENB) {
+ param_new |= MAX3100_PE;
+ parity |= MAX3100_PARITY_ON;
+ } else {
+ param_new &= ~MAX3100_PE;
+ parity &= ~MAX3100_PARITY_ON;
+ }
+ param_mask |= MAX3100_PE;
+
+ if (cflag & PARODD)
+ parity |= MAX3100_PARITY_ODD;
+ else
+ parity &= ~MAX3100_PARITY_ODD;
+
+ s->port.ignore_status_mask = 0;
+ if (termios->c_iflag & IGNPAR)
+ s->port.ignore_status_mask |=
+ MAX3100_STATUS_PE | MAX3100_STATUS_FE |
+ MAX3100_STATUS_OE;
+
+ if (s->poll_time > 0)
+ del_timer_sync(&s->timer);
+
+ uart_update_timeout(port, termios->c_cflag, baud);
+
+ spin_lock(&s->conf_lock);
+ s->conf = (s->conf & ~param_mask) | (param_new & param_mask);
+ s->conf_commit = 1;
+ s->parity = parity;
+ spin_unlock(&s->conf_lock);
+ max3100_dowork(s);
+
+ if (UART_ENABLE_MS(&s->port, termios->c_cflag))
+ max3100_enable_ms(&s->port);
+ }
+}
+
+static void max3100_shutdown(struct uart_port *port)
+{
+ struct max3100_port_s *s = container_of(port,
+ struct max3100_port_s,
+ port);
+
+ dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+ if (s->suspending)
+ return;
+
+ s->force_end_work = 1;
+
+ if (s->poll_time > 0)
+ del_timer_sync(&s->timer);
+
+ if (s->workqueue) {
+ flush_workqueue(s->workqueue);
+ destroy_workqueue(s->workqueue);
+ }
+ if (s->irq)
+ free_irq(s->irq, s);
+
+ /* set shutdown mode to save power */
+ if (s->max3100_hw_suspend)
+ s->max3100_hw_suspend(1);
+ else {
+ u16 tx, rx;
+
+ tx = MAX3100_WC | MAX3100_SHDN;
+ max3100_sr(s, tx, &rx);
+ }
+}
+
+static int max3100_startup(struct uart_port *port)
+{
+ struct max3100_port_s *s = container_of(port,
+ struct max3100_port_s,
+ port);
+ char b[10];
+ int irq_type;
+
+ dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+ s->conf = MAX3100_RM;
+ s->rx_enabled = 1;
+
+ if (s->suspending)
+ return 0;
+
+ s->force_end_work = 0;
+ s->parity = 0;
+ s->rts = 0;
+
+ sprintf(b, "max3100-%d", s->minor);
+ s->workqueue = create_freezeable_workqueue(b);
+ if (!s->workqueue) {
+ dev_warn(&s->spi->dev, "cannot create workqueue\n");
+ return -EBUSY;
+ }
+ INIT_WORK(&s->work, max3100_work);
+
+ s->irq_status = 1; /* IRQS are on after request */
+ if (s->only_edge_irq)
+ irq_type = IRQF_TRIGGER_FALLING;
+ else
+ irq_type = IRQF_TRIGGER_LOW;
+ if (request_irq(s->irq, max3100_irq, irq_type, "max3100", s) < 0) {
+ dev_warn(&s->spi->dev, "cannot allocate irq %d\n", s->irq);
+ s->irq = 0;
+ return -EBUSY;
+ }
+
+ if (s->loopback) {
+ u16 tx, rx;
+ tx = 0x4001;
+ max3100_sr(s, tx, &rx);
+ }
+
+ if (s->max3100_hw_suspend)
+ s->max3100_hw_suspend(0);
+ s->conf_commit = 1;
+ max3100_dowork(s);
+ /* wait for clock to settle */
+ msleep(50);
+
+ max3100_enable_ms(&s->port);
+
+ return 0;
+}
+
+static const char *max3100_type(struct uart_port *port)
+{
+ struct max3100_port_s *s = container_of(port,
+ struct max3100_port_s,
+ port);
+
+ dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+ return s->port.type == PORT_MAX3100 ? "MAX3100" : NULL;
+}
+
+static void max3100_release_port(struct uart_port *port)
+{
+ struct max3100_port_s *s = (struct max3100_port_s *)port;
+
+ dev_dbg(&s->spi->dev, "%s\n", __func__);
+}
+
+static void max3100_config_port(struct uart_port *port, int flags)
+{
+ struct max3100_port_s *s = container_of(port,
+ struct max3100_port_s,
+ port);
+
+ dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+ if (flags & UART_CONFIG_TYPE)
+ s->port.type = PORT_MAX3100;
+}
+
+static int max3100_verify_port(struct uart_port *port,
+ struct serial_struct *ser)
+{
+ struct max3100_port_s *s = container_of(port,
+ struct max3100_port_s,
+ port);
+ int ret = -EINVAL;
+
+ dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+ if (ser->type == PORT_UNKNOWN || ser->type == PORT_MAX3100)
+ ret = 0;
+ return ret;
+}
+
+static void max3100_stop_tx(struct uart_port *port)
+{
+ struct max3100_port_s *s = container_of(port,
+ struct max3100_port_s,
+ port);
+
+ dev_dbg(&s->spi->dev, "%s\n", __func__);
+}
+
+static int max3100_request_port(struct uart_port *port)
+{
+ struct max3100_port_s *s = container_of(port,
+ struct max3100_port_s,
+ port);
+
+ dev_dbg(&s->spi->dev, "%s\n", __func__);
+ return 0;
+}
+
+static void max3100_break_ctl(struct uart_port *port, int break_state)
+{
+ struct max3100_port_s *s = container_of(port,
+ struct max3100_port_s,
+ port);
+
+ dev_dbg(&s->spi->dev, "%s\n", __func__);
+}
+
+static struct uart_ops max3100_ops = {
+ .tx_empty = max3100_tx_empty,
+ .set_mctrl = max3100_set_mctrl,
+ .get_mctrl = max3100_get_mctrl,
+ .stop_tx = max3100_stop_tx,
+ .start_tx = max3100_start_tx,
+ .stop_rx = max3100_stop_rx,
+ .enable_ms = max3100_enable_ms,
+ .break_ctl = max3100_break_ctl,
+ .startup = max3100_startup,
+ .shutdown = max3100_shutdown,
+ .set_termios = max3100_set_termios,
+ .type = max3100_type,
+ .release_port = max3100_release_port,
+ .request_port = max3100_request_port,
+ .config_port = max3100_config_port,
+ .verify_port = max3100_verify_port,
+};
+
+static struct uart_driver max3100_uart_driver = {
+ .owner = THIS_MODULE,
+ .driver_name = "ttyMAX",
+ .dev_name = "ttyMAX",
+ .major = MAX3100_MAJOR,
+ .minor = MAX3100_MINOR,
+ .nr = MAX_MAX3100,
+};
+static int uart_driver_registered;
+
+static int __devinit max3100_probe(struct spi_device *spi)
+{
+ int i, retval;
+ struct plat_max3100 *pdata;
+ u16 tx, rx;
+
+ if (!uart_driver_registered) {
+ uart_driver_registered = 1;
+ retval = uart_register_driver(&max3100_uart_driver);
+ if (retval) {
+ printk(KERN_ERR "Couldn't register max3100 uart driver\n");
+ return retval;
+ }
+ }
+
+ for (i = 0; i < MAX_MAX3100; i++)
+ if (!max3100s[i])
+ break;
+ if (i == MAX_MAX3100) {
+ dev_warn(&spi->dev, "too many MAX3100 chips\n");
+ return -ENOMEM;
+ }
+
+ max3100s[i] = kzalloc(sizeof(struct max3100_port_s), GFP_KERNEL);
+ if (!max3100s[i]) {
+ dev_warn(&spi->dev,
+ "kmalloc for max3100 structure %d failed!\n", i);
+ return -ENOMEM;
+ }
+ max3100s[i]->spi = spi;
+ max3100s[i]->irq = spi->irq;
+ spin_lock_init(&max3100s[i]->conf_lock);
+ dev_set_drvdata(&spi->dev, max3100s[i]);
+ pdata = spi->dev.platform_data;
+ max3100s[i]->crystal = pdata->crystal;
+ max3100s[i]->loopback = pdata->loopback;
+ max3100s[i]->only_edge_irq = pdata->only_edge_irq;
+ max3100s[i]->poll_time = pdata->poll_time * HZ / 1000;
+ if (pdata->poll_time > 0 && max3100s[i]->poll_time == 0)
+ max3100s[i]->poll_time = 1;
+ max3100s[i]->max3100_hw_suspend = pdata->max3100_hw_suspend;
+ max3100s[i]->minor = i;
+ init_timer(&max3100s[i]->timer);
+ max3100s[i]->timer.function = max3100_timeout;
+ max3100s[i]->timer.data = (unsigned long) max3100s[i];
+
+ dev_dbg(&spi->dev, "%s: adding port %d\n", __func__, i);
+ max3100s[i]->port.irq = max3100s[i]->irq;
+ max3100s[i]->port.uartclk = max3100s[i]->crystal ? 3686400 : 1843200;
+ max3100s[i]->port.fifosize = 16;
+ max3100s[i]->port.ops = &max3100_ops;
+ max3100s[i]->port.flags = UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;
+ max3100s[i]->port.line = i;
+ max3100s[i]->port.type = PORT_MAX3100;
+ max3100s[i]->port.dev = &spi->dev;
+ retval = uart_add_one_port(&max3100_uart_driver, &max3100s[i]->port);
+ if (retval < 0)
+ dev_warn(&spi->dev,
+ "uart_add_one_port failed for line %d with error %d\n",
+ i, retval);
+
+ /* set shutdown mode to save power. Will be woken-up on open */
+ if (max3100s[i]->max3100_hw_suspend)
+ max3100s[i]->max3100_hw_suspend(1);
+ else {
+ tx = MAX3100_WC | MAX3100_SHDN;
+ max3100_sr(max3100s[i], tx, &rx);
+ }
+ return 0;
+}
+
+static int __devexit max3100_remove(struct spi_device *spi)
+{
+ struct max3100_port_s *s = dev_get_drvdata(&spi->dev);
+ int i;
+
+ /* find out the index for the chip we are removing */
+ for (i = 0; i < MAX_MAX3100; i++)
+ if (max3100s[i] == s)
+ break;
+
+ dev_dbg(&spi->dev, "%s: removing port %d\n", __func__, i);
+ uart_remove_one_port(&max3100_uart_driver, &max3100s[i]->port);
+ kfree(max3100s[i]);
+ max3100s[i] = NULL;
+
+ /* check if this is the last chip we have */
+ for (i = 0; i < MAX_MAX3100; i++)
+ if (max3100s[i])
+ return 0;
+ pr_debug("removing max3100 driver\n");
+ uart_unregister_driver(&max3100_uart_driver);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+
+static int max3100_suspend(struct spi_device *spi, pm_message_t state)
+{
+ struct max3100_port_s *s = dev_get_drvdata(&spi->dev);
+
+ dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+ s->suspending = 1;
+ uart_suspend_port(&max3100_uart_driver, &s->port);
+
+ irq_state(s, 0);
+ synchronize_irq(s->irq);
+
+ if (s->max3100_hw_suspend)
+ s->max3100_hw_suspend(1);
+ else {
+ /* no HW suspend, so do SW one */
+ u16 tx, rx;
+
+ tx = MAX3100_WC | MAX3100_SHDN;
+ max3100_sr(s, tx, &rx);
+ }
+ return 0;
+}
+
+static int max3100_resume(struct spi_device *spi)
+{
+ struct max3100_port_s *s = dev_get_drvdata(&spi->dev);
+
+ dev_dbg(&s->spi->dev, "%s\n", __func__);
+
+ irq_state(s, 1);
+
+ if (s->max3100_hw_suspend)
+ s->max3100_hw_suspend(0);
+ s->conf_commit = 1;
+ max3100_dowork(s);
+
+ uart_resume_port(&max3100_uart_driver, &s->port);
+ s->suspending = 0;
+
+ return 0;
+}
+
+#else
+#define max3100_suspend NULL
+#define max3100_resume NULL
+#endif
+
+static struct spi_driver max3100_driver = {
+ .driver = {
+ .name = "max3100",
+ .bus = &spi_bus_type,
+ .owner = THIS_MODULE,
+ },
+
+ .probe = max3100_probe,
+ .remove = __devexit_p(max3100_remove),
+ .suspend = max3100_suspend,
+ .resume = max3100_resume,
+};
+
+
+static int __init max3100_init(void)
+{
+ return spi_register_driver(&max3100_driver);
+}
+module_init(max3100_init);
+
+static void __exit max3100_exit(void)
+{
+ spi_unregister_driver(&max3100_driver);
+}
+module_exit(max3100_exit);
+
+MODULE_DESCRIPTION("MAX3100 driver");
+MODULE_AUTHOR("Christian Pellegrin <chripell@evolware.org>");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 3b2f6c0..32c9fa9 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -155,6 +155,9 @@

#define PORT_SC26XX 82

+/* MAX3100 */
+#define PORT_MAX3100 83
+
#ifdef __KERNEL__

#include <linux/compiler.h>
diff --git a/include/linux/serial_max3100.h b/include/linux/serial_max3100.h
new file mode 100644
index 0000000..d1b4622
--- /dev/null
+++ b/include/linux/serial_max3100.h
@@ -0,0 +1,31 @@
+
+/*
+ *
+ * Copyright (C) 2007 Christian Pellegrin
+ *
+ * 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.
+ */
+
+
+#ifndef _LINUX_SERIAL_MAX3100_H
+#define _LINUX_SERIAL_MAX3100_H 1
+
+struct plat_max3100 {
+/* force MAX3100 in loopback */
+ int loopback;
+/* 0 for 3.6864 Mhz, 1 for 1.8432 */
+ int crystal;
+/* for archs like PXA with only edge irqs */
+ int only_edge_irq;
+/* MAX3100 has a shutdown pin. This is a hook
+ called on suspend and resume to activate it.*/
+ void (*max3100_hw_suspend) (int suspend);
+/* poll time for ctr signals in ms, 0 disables (so no hw flow
+ * ctrl is possible) */
+ int poll_time;
+};
+
+#endif
--
1.4.4.4