This patch adds support for the MAX3100 SPI UART.
Generated on 20071217 against v2.6.23
Signed-off-by: Christian Pellegrin <[email protected]>
---
drivers/serial/Kconfig | 7 +
drivers/serial/Makefile | 1 +
drivers/serial/max3100.c | 956 ++++++++++++++++++++++++++++++++++++++++
include/linux/serial_max3100.h | 25 +
4 files changed, 989 insertions(+), 0 deletions(-)
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 81b52b7..4e7111b 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -461,6 +461,13 @@ config SERIAL_S3C2410_CONSOLE
your boot loader about how to pass options to the kernel at
boot time.)
+config SERIAL_MAX3100
+ tristate "MAX3100 support"
+ depends on SPI
+ help
+ MAX3100 chip support
+
+
config SERIAL_DZ
bool "DECstation DZ serial driver"
depends on MACH_DECSTATION && 32BIT
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile
index af6377d..9f67e52 100644
--- a/drivers/serial/Makefile
+++ b/drivers/serial/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_SERIAL_PNX8XXX) += pnx8xxx_uart.o
obj-$(CONFIG_SERIAL_SA1100) += sa1100.o
obj-$(CONFIG_SERIAL_BFIN) += bfin_5xx.o
obj-$(CONFIG_SERIAL_S3C2410) += s3c2410.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..d07936d
--- /dev/null
+++ b/drivers/serial/max3100.c
@@ -0,0 +1,956 @@
+
+/*
+ *
+ * Copyright (C) 2007 Christian Pellegrin <[email protected]>
+ *
+ * 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,
+};
+
+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 to prevent clashes with ttyS:
+ * mknod /dev/ttyMAX0 c 4 128
+ */
+
+#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/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 <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)
+
+struct max3100_port_s {
+ struct uart_port port;
+ struct spi_device *spi;
+ struct tty_struct *tty;
+
+ struct mutex spi_txrx;/* protects access to the hw */
+
+ int rts; /* rts status, can be MAX3100_RTS or 0 */
+ int conf; /* configuration for the MAX31000
+ * (bits 0-7, bits 8-11 are irqs) */
+ int last_cts_rx; /* last CTS received for flow ctrl */
+
+ int tx_buf_cur; /* current char to tx */
+ int tx_buf_tot; /* current number of chars in tx buf */
+ unsigned char *tx_buf;
+ /* shared tx buffer spinlock (no sem
+ * since write may sleep) */
+ spinlock_t tx_buf_lock;
+
+ int tx_stopped; /* when we should not send chars */
+ int parity; /* keeps track if we should work parity */
+#define MAX3100_PARITY_ON 1
+#define MAX3100_PARITY_ODD 2
+#define MAX3100_7BIT 4
+
+ int irq; /* irq assigned to the max3100 */
+
+ int minor; /* minor number */
+ int crystal; /* 1 if 3.6864Mhz crystal 0 for 1.8432 */
+ int loopback; /* 1 if we are in loopback mode */
+ int only_edge_irq; /* 1 if we have only edge irqs (like PXA) */
+
+ int ref_count; /* how many users */
+ struct mutex sem; /* protects us during open/close */
+
+ /* 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;
+
+ /* these are for IRQ on/off counting */
+ int irq_status;
+ /* avoid race condition on irq_status */
+ spinlock_t irq_lock;
+
+ /* signals when we done sending current buffer */
+ wait_queue_head_t all_sent;
+};
+
+/* global since we do register the driver only once */
+static struct tty_driver *serial_driver;
+
+/* 4 MAX3100s should be enough for everyone */
+#define MAX_MAX3100 4
+static struct max3100_port_s *max3100s[MAX_MAX3100]; /* the chips */
+
+/* our buffer for sending chars */
+#define MAX3100_TX_BUF_N 16
+
+/* how many chars we wait befor flipping tty buffer */
+#define MAX3100_FLIP_EVERY 8
+
+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>>9) & 1);
+}
+
+static void max3100_calc_parity(struct max3100_port_s *s, u16 *c)
+{
+ *c &= ~MAX3100_PT;
+ *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) {
+ PREPARE_WORK(&s->work, max3100_work);
+ queue_work(s->workqueue, &s->work);
+ }
+}
+
+static int max3100_sr(struct max3100_port_s *s, u16 tx, u16 *rx, int push)
+{
+ /* note: we suppose that the T bit from conf_status is in sync
+ * with the hw one, so all the communication must go through
+ * this function */
+ struct spi_message message;
+ struct spi_transfer tran;
+ int status, flag;
+ u16 etx, erx;
+ int got_char = 0;
+
+ mutex_lock(&s->spi_txrx);
+
+ if (s->loopback) {
+ if ((tx & MAX3100_CMD) == MAX3100_RC)
+ tx |= 1;
+ }
+ 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 0;
+ }
+ *rx = ntohs(erx);
+ dev_dbg(&s->spi->dev, "%04x - %04x\n", tx, *rx);
+
+ if ((tx & MAX3100_CMD) == MAX3100_RD ||
+ (tx & MAX3100_CMD) == MAX3100_WD)
+ s->last_cts_rx = *rx;
+
+ if (*rx & MAX3100_R &&
+ ((tx & MAX3100_CMD) == MAX3100_RD ||
+ (tx & MAX3100_CMD) == MAX3100_WD)) {
+ got_char = 1;
+ if (tty_buffer_request_room(s->tty, 1) == 0) {
+ dev_warn(&s->spi->dev, "no room in tty buffer\n");
+ tty_schedule_flip(s->tty);
+ }
+
+ flag = TTY_NORMAL;
+ if (*rx & MAX3100_RAFE) {
+ s->port.icount.frame++;
+ flag = TTY_FRAME;
+ }
+ if (s->parity & MAX3100_PARITY_ON &&
+ max3100_check_parity(s, *rx)) {
+ s->port.icount.parity++;
+ flag = TTY_PARITY;
+ }
+ tty_insert_flip_char(s->tty, *rx & MAX3100_DATA, flag);
+ }
+
+ mutex_unlock(&s->spi_txrx);
+
+ if (push && got_char)
+ tty_schedule_flip(s->tty);
+ return got_char;
+}
+
+
+static void max3100_send_conf(struct max3100_port_s *s)
+{
+ u16 tx = 0, rx;
+
+ tx = MAX3100_WC | (s->conf & 0x0fff);
+ max3100_sr(s, tx, &rx, 1);
+}
+
+static int max3100_ok_to_send(struct max3100_port_s *s)
+{
+ if (C_CRTSCTS(s->tty)) {
+ if ((s->last_cts_rx & MAX3100_CTS) == 0)
+ return 0;
+ }
+ return !s->tx_stopped;
+}
+
+static void max3100_work(struct work_struct *w)
+{
+ struct max3100_port_s *s = container_of(w, struct max3100_port_s, work);
+ u16 tx, rx;
+ int nchars; /* number of char waiting in the send buf */
+ int rxchars = 0; /* chars received */
+
+ do {
+ unsigned long flags;
+
+ tx = MAX3100_RD;
+ rxchars += max3100_sr(s, tx, &rx, 0);
+ /* rx a char so we get MAX3100_T and CTS current */
+
+ spin_lock_irqsave(&s->tx_buf_lock, flags);
+ nchars = s->tx_buf_tot - s->tx_buf_cur;
+ tx = MAX3100_WD | s->rts;
+ tx |= s->tx_buf[s->tx_buf_cur];
+ spin_unlock_irqrestore(&s->tx_buf_lock, flags);
+
+ if ((rx & MAX3100_T) && /* tx buffer empty*/
+ max3100_ok_to_send(s) && /* fw ctrl decision */
+ nchars > 0 && /* more to send */
+ !s->force_end_work) {
+ if (s->parity & MAX3100_PARITY_ON)
+ max3100_calc_parity(s, &tx);
+ rxchars += max3100_sr(s, tx, &rx, 0);
+ nchars -= 1;
+ spin_lock_irqsave(&s->tx_buf_lock, flags);
+ s->tx_buf_cur += 1;
+ spin_unlock_irqrestore(&s->tx_buf_lock, flags);
+ if (nchars == 0) {
+ tty_wakeup(s->tty);
+ wake_up(&s->all_sent);
+ }
+ }
+ if (rxchars > MAX3100_FLIP_EVERY) {
+ tty_schedule_flip(s->tty);
+ rxchars = 0;
+ }
+ }
+ while ((nchars > 0 || /* more to send */
+ rx & MAX3100_R) && /* try to empy all the RX buffer */
+ !s->force_end_work);
+ if (rxchars)
+ tty_schedule_flip(s->tty);
+ if (!s->only_edge_irq && !s->force_end_work)
+ irq_state(s, 1);
+}
+
+static irqreturn_t max3100_irq(int irqno, void *dev_id)
+{
+ struct max3100_port_s *s = dev_id;
+
+ if (!s->only_edge_irq)
+ irq_state(s, 0); /* avoid irq storm */
+ max3100_dowork(s);
+ return IRQ_HANDLED;
+}
+
+static void rs_stop(struct tty_struct *tty)
+{
+ struct max3100_port_s *s = tty->driver_data;
+
+ s->tx_stopped = 1;
+}
+
+static void rs_start(struct tty_struct *tty)
+{
+ struct max3100_port_s *s = tty->driver_data;
+
+ s->tx_stopped = 0;
+}
+
+static void rs_flush_chars(struct tty_struct *tty)
+{
+}
+
+static void rs_wait_until_sent(struct tty_struct *tty, int timeout)
+{
+ struct max3100_port_s *s = tty->driver_data;
+
+ wait_event_timeout(s->all_sent,
+ s->tx_buf_tot == 0 || s->tx_buf_tot == s->tx_buf_cur,
+ timeout);
+}
+
+static void rs_flush_buffer(struct tty_struct *tty)
+{
+ struct max3100_port_s *s = tty->driver_data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&s->tx_buf_lock, flags);
+ s->tx_buf_cur = 0;
+ s->tx_buf_tot = 0;
+ spin_unlock_irqrestore(&s->tx_buf_lock, flags);
+}
+
+static int rs_write(struct tty_struct *tty,
+ const unsigned char *buf, int count)
+{
+ struct max3100_port_s *s = tty->driver_data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&s->tx_buf_lock, flags);
+ if (s->tx_buf_cur < s->tx_buf_tot) {
+ count = 0;
+ } else {
+ if (count > MAX3100_TX_BUF_N)
+ count = MAX3100_TX_BUF_N;
+ memcpy(s->tx_buf, buf, count);
+ s->tx_buf_cur = 0;
+ s->tx_buf_tot = count;
+ }
+ spin_unlock_irqrestore(&s->tx_buf_lock, flags);
+ max3100_dowork(s);
+ return count;
+}
+
+static int rs_write_room(struct tty_struct *tty)
+{
+ struct max3100_port_s *s = tty->driver_data;
+ int ret;
+ unsigned long flags;
+
+ spin_lock_irqsave(&s->tx_buf_lock, flags);
+ if (s->tx_buf_cur < s->tx_buf_tot)
+ ret = 0;
+ else
+ ret = MAX3100_TX_BUF_N;
+ spin_unlock_irqrestore(&s->tx_buf_lock, flags);
+ return ret;
+}
+
+static int rs_chars_in_buffer(struct tty_struct *tty)
+{
+ struct max3100_port_s *s = tty->driver_data;
+ int ret;
+ unsigned long flags;
+
+ spin_lock_irqsave(&s->tx_buf_lock, flags);
+ if (s->tx_buf_cur < s->tx_buf_tot)
+ ret = MAX3100_TX_BUF_N;
+ else
+ ret = 0;
+ spin_unlock_irqrestore(&s->tx_buf_lock, flags);
+ return ret;
+}
+
+static void internal_throttle(struct tty_struct *tty, char ch, int rts)
+{
+ struct max3100_port_s *s = tty->driver_data;
+ u16 tx = 0, rx;
+ int old_tx_stopped;
+
+ old_tx_stopped = s->tx_stopped;
+ s->tx_stopped = 1;
+ tx = MAX3100_RD;
+ /* wait for tx buf empty. Unfortunately we cannot avoid a busy
+ loop (it should not take much since we block tx ... so at
+ most a byte time) since TX empty interrupt is unusable (see
+ Notes on top) */
+ do {
+ max3100_sr(s, tx, &rx, 1);
+ schedule();
+ } while ((rx & MAX3100_T) == 0);
+
+ if (I_IXOFF(tty))
+ tx = MAX3100_WD | s->rts | (ch&0xff);
+ if (C_CRTSCTS(tty)) {
+ s->rts = rts ? (MAX3100_RTS) : 0;
+ tx = MAX3100_WD | s->rts | MAX3100_TE;
+ }
+ if (tx)
+ max3100_sr(s, tx, &rx, 1);
+ s->tx_stopped = old_tx_stopped;
+}
+
+static void rs_throttle(struct tty_struct *tty)
+{
+ internal_throttle(tty, STOP_CHAR(tty), 0);
+}
+
+static void rs_unthrottle(struct tty_struct *tty)
+{
+ internal_throttle(tty, START_CHAR(tty), 1);
+}
+
+static int get_lsr_info(struct max3100_port_s *s, unsigned int *value)
+{
+ unsigned char status;
+ u16 tx = 0, rx;
+
+ tx = MAX3100_RD;
+ max3100_sr(s, tx, &rx, 1);
+ status = (rx & MAX3100_CTS) > 0;
+ return put_user(status, value);
+}
+
+static int rs_ioctl(struct tty_struct *tty, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct max3100_port_s *s = tty->driver_data;
+ int retval = 0;
+
+ switch (cmd) {
+
+ case TIOCSERGETLSR: /* Get line status register */
+ return get_lsr_info(s, (unsigned int *) arg);
+
+ default:
+ retval = -ENOIOCTLCMD ;
+ }
+ return retval;
+}
+
+static void change_speed(struct max3100_port_s *s)
+{
+ unsigned cflag;
+ unsigned i;
+ u32 param_new;
+ u32 param_mask;
+
+ cflag = s->tty->termios->c_cflag;
+ param_new = 0;
+ param_mask = 0;
+
+ i = cflag & CBAUD;
+ /* note: supposed 3.6864 Mhz xtal */
+ switch (i) {
+ case B300:
+ if (s->crystal) {
+ param_new = 16;
+ } else {
+ dev_warn(&s->spi->dev, "unsupported baud rate!\n");
+ param_new = 15;
+ }
+ break;
+ case B600:
+ param_new = 15;
+ break;
+ case B1200:
+ param_new = 14;
+ break;
+ case B2400:
+ param_new = 13;
+ break;
+ case B4800:
+ param_new = 12;
+ break;
+ case B9600:
+ param_new = 11;
+ break;
+ case B19200:
+ param_new = 10;
+ break;
+ case B38400:
+ param_new = 9;
+ break;
+ case B57600:
+ param_new = 2;
+ break;
+ case B115200:
+ param_new = 1;
+ break;
+ case B230400:
+ if (s->crystal) {
+ param_new = 1;
+ dev_warn(&s->spi->dev, "unsupported baud rate!\n");
+ } else {
+ param_new = 0;
+ }
+ 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;
+ s->parity &= ~MAX3100_7BIT;
+ } else {
+ param_new |= MAX3100_L;
+ s->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;
+ s->parity |= MAX3100_PARITY_ON;
+ } else {
+ param_new &= ~MAX3100_PE;
+ s->parity &= ~MAX3100_PARITY_ON;
+ }
+ param_mask |= MAX3100_PE;
+
+ if (cflag & PARODD) {
+ s->parity |= MAX3100_PARITY_ODD;
+ } else {
+ s->parity &= ~MAX3100_PARITY_ODD;
+ }
+
+ s->conf = (s->conf & ~param_mask) | (param_new & param_mask);
+ max3100_send_conf(s);
+
+ return;
+}
+
+
+static void rs_set_termios(struct tty_struct *tty, struct ktermios *old_termios)
+{
+ struct max3100_port_s *s = tty->driver_data;
+
+ if (tty->termios->c_cflag == old_termios->c_cflag)
+ return;
+
+ change_speed(s);
+
+ if ((old_termios->c_cflag & CRTSCTS) &&
+ !(tty->termios->c_cflag & CRTSCTS))
+ max3100_dowork(s);
+}
+
+static void shutdown(struct max3100_port_s *s)
+{
+ s->force_end_work = 1;
+ if (s->workqueue) {
+ flush_workqueue(s->workqueue);
+ destroy_workqueue(s->workqueue);
+ }
+ if (s->irq)
+ free_irq(s->irq, s);
+ kfree(s->tx_buf);
+ s->tx_buf = NULL;
+ if (s->tty)
+ set_bit(TTY_IO_ERROR, &s->tty->flags);
+}
+
+static void rs_hangup(struct tty_struct *tty)
+{
+ struct max3100_port_s *s = tty->driver_data;
+
+ shutdown(s);
+}
+
+static int startup(struct max3100_port_s *s)
+{
+ char b[10];
+ int irq_type;
+
+ s->tx_buf = kmalloc(MAX3100_TX_BUF_N, GFP_KERNEL);
+ if (s->tx_buf == NULL)
+ return -ENOMEM;
+ s->tx_buf_cur = 0;
+ s->tx_buf_tot = 0;
+
+ s->force_end_work = 0;
+ s->parity = 0;
+ s->rts = 0;
+ s->tx_stopped = 0;
+ s->conf = MAX3100_RM;
+
+ sprintf(b, "max3100-%d", s->minor);
+ s->workqueue = create_singlethread_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;
+ kfree(s->tx_buf);
+ return -EBUSY;
+ }
+
+ if (s->tty)
+ clear_bit(TTY_IO_ERROR, &s->tty->flags);
+
+ change_speed(s);
+
+ if (s->loopback) {
+ u16 tx, rx;
+ tx = 0x4001;
+ max3100_sr(s, tx, &rx, 1);
+ }
+
+ return 0;
+}
+
+int rs_open(struct tty_struct *tty, struct file *filp)
+{
+ struct max3100_port_s *s;
+ int retval = 0, line;
+
+ line = tty->index;
+
+ if (line >= MAX_MAX3100 || line < 0)
+ return -ENODEV;
+
+ s = max3100s[line];
+
+ if (!s) {
+ printk(KERN_ERR "Nonexistent max3100 for index %d\n", line);
+ return -ENODEV;
+ }
+
+ retval = mutex_lock_interruptible(&s->sem);
+ if (retval < 0)
+ return retval;
+
+ s->ref_count++;
+
+ if (s->ref_count == 1) {
+ tty->driver_data = s;
+ s->tty = tty;
+
+ retval = startup(s);
+ }
+
+ mutex_unlock(&s->sem);
+
+ return retval;
+}
+
+static void rs_close(struct tty_struct *tty, struct file *filp)
+{
+ struct max3100_port_s *s = tty->driver_data;
+
+ mutex_lock(&s->sem);
+
+ s->ref_count--;
+ if (s->ref_count == 0)
+ shutdown(s);
+
+ mutex_unlock(&s->sem);
+}
+
+static int rs_tiocmget(struct tty_struct *tty, struct file *file)
+{
+ struct max3100_port_s *s = tty->driver_data;
+ u16 tx, rx;
+ unsigned int result;
+
+ tx = MAX3100_RD;
+ max3100_sr(s, tx, &rx, 1);
+
+ result = ((s->rts) ? TIOCM_RTS : 0)
+ | ((rx & MAX3100_CTS) ? TIOCM_CTS : 0);
+ return result;
+}
+
+static int rs_tiocmset(struct tty_struct *tty, struct file *file,
+ unsigned int set, unsigned int clear)
+{
+ struct max3100_port_s *s = tty->driver_data;
+ int old_rts = s->rts;
+ u16 tx, rx;
+
+ if (set & TIOCM_RTS)
+ s->rts = MAX3100_RTS;
+ if (clear & TIOCM_RTS)
+ s->rts = 0;
+
+ if (s->rts != old_rts) {
+ tx = MAX3100_WD | s->rts | MAX3100_TE;
+ max3100_sr(s, tx, &rx, 1);
+ }
+ return 0;
+}
+
+static struct tty_operations rs_ops = {
+ .open = rs_open,
+ .close = rs_close,
+ .write = rs_write,
+ .flush_chars = rs_flush_chars,
+ .wait_until_sent = rs_wait_until_sent,
+ .write_room = rs_write_room,
+ .chars_in_buffer = rs_chars_in_buffer,
+ .flush_buffer = rs_flush_buffer,
+ .ioctl = rs_ioctl,
+ .throttle = rs_throttle,
+ .unthrottle = rs_unthrottle,
+ .set_termios = rs_set_termios,
+ .stop = rs_stop,
+ .start = rs_start,
+ .hangup = rs_hangup,
+ .tiocmget = rs_tiocmget,
+ .tiocmset = rs_tiocmset,
+};
+
+static int __devinit max3100_probe(struct spi_device *spi)
+{
+ int i;
+ struct plat_max3100 *pdata;
+
+ if (!serial_driver) {
+ serial_driver = alloc_tty_driver(MAX_MAX3100);
+ if (!serial_driver) {
+ printk(KERN_ERR "Cannot allocate serial driver\n");
+ return -ENOMEM;
+ }
+
+ serial_driver->name = "ttyMAX";
+ serial_driver->driver_name = "ttyMAX";
+ serial_driver->major = TTY_MAJOR;
+ /* this should prevent clashes */
+ serial_driver->minor_start = 128;
+ serial_driver->type = TTY_DRIVER_TYPE_SERIAL;
+ serial_driver->subtype = SERIAL_TYPE_NORMAL;
+ serial_driver->init_termios = tty_std_termios;
+ serial_driver->init_termios.c_cflag =
+ B9600 | CS8 | CREAD | HUPCL | CLOCAL;
+ serial_driver->flags = TTY_DRIVER_REAL_RAW |
+ TTY_DRIVER_DYNAMIC_DEV;
+ tty_set_operations(serial_driver, &rs_ops);
+
+ if (tty_register_driver(serial_driver)) {
+ put_tty_driver(serial_driver);
+ printk(KERN_ERR "Couldn't register serial driver\n");
+ return -EINVAL;
+ }
+ }
+
+ 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;
+ mutex_init(&max3100s[i]->sem);
+ mutex_init(&max3100s[i]->spi_txrx);
+ spin_lock_init(&max3100s[i]->tx_buf_lock);
+ spin_lock_init(&max3100s[i]->irq_lock);
+ init_waitqueue_head(&max3100s[i]->all_sent);
+ 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]->minor = i;
+ tty_register_device(serial_driver, i, &spi->dev);
+
+ return 0;
+}
+
+static int __devexit max3100_remove(struct spi_device *spi)
+{
+ int i;
+
+ i = 0;
+
+ for (i = 0; i < MAX_MAX3100; i++)
+ if (max3100s[i] && max3100s[i]->ref_count > 0)
+ return -EBUSY;
+
+ for (i = 0; i < MAX_MAX3100; i++)
+ if (max3100s[i]) {
+ tty_unregister_device(serial_driver, i);
+ kfree(max3100s[i]);
+ max3100s[i] = NULL;
+ }
+
+ if (serial_driver)
+ tty_unregister_driver(serial_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);
+ u16 tx, rx;
+
+ tx = MAX3100_WC | MAX3100_SHDN;
+ max3100_sr(s, tx, &rx, 0);
+ return 0;
+}
+
+static int max3100_resume(struct spi_device *spi)
+{
+ struct max3100_port_s *s = dev_get_drvdata(&spi->dev);
+
+ max3100_send_conf(s);
+
+ 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_LICENSE("GPL");
diff --git a/include/linux/serial_max3100.h b/include/linux/serial_max3100.h
new file mode 100644
index 0000000..c6b5c45
--- /dev/null
+++ b/include/linux/serial_max3100.h
@@ -0,0 +1,25 @@
+
+/*
+ *
+ * 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 {
+ int loopback;
+/* force MAX3100 in loopback */
+ int crystal;
+/* 0 for 3.6864 Mhz, 1 for 1.8432 */
+ int only_edge_irq;
+/* for archs like PXA with only edge irqs */
+};
+
+#endif
--
1.4.4.4
On 12/17/2007 09:17 AM, [email protected] wrote:
> This patch adds support for the MAX3100 SPI UART.
>
> Generated on 20071217 against v2.6.23
>
> Signed-off-by: Christian Pellegrin <[email protected]>
> ---
> drivers/serial/Kconfig | 7 +
> drivers/serial/Makefile | 1 +
> drivers/serial/max3100.c | 956 ++++++++++++++++++++++++++++++++++++++++
> include/linux/serial_max3100.h | 25 +
> 4 files changed, 989 insertions(+), 0 deletions(-)
>
[...]
> diff --git a/drivers/serial/max3100.c b/drivers/serial/max3100.c
> new file mode 100644
> index 0000000..d07936d
> --- /dev/null
> +++ b/drivers/serial/max3100.c
[...]
> +static int __devexit max3100_remove(struct spi_device *spi)
> +{
> + int i;
> +
> + i = 0;
> +
> + for (i = 0; i < MAX_MAX3100; i++)
> + if (max3100s[i] && max3100s[i]->ref_count > 0)
> + return -EBUSY;
> +
> + for (i = 0; i < MAX_MAX3100; i++)
> + if (max3100s[i]) {
> + tty_unregister_device(serial_driver, i);
> + kfree(max3100s[i]);
> + max3100s[i] = NULL;
> + }
> +
> + if (serial_driver)
> + tty_unregister_driver(serial_driver);
You probably wanted to unregister it after _all_ cards are removed, not after
each...
> + 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);
> + u16 tx, rx;
> +
> + tx = MAX3100_WC | MAX3100_SHDN;
> + max3100_sr(s, tx, &rx, 0);
Also you should synchronize_irq() after stopping them here.
> + return 0;
> +}
regards,
--
Jiri Slaby ([email protected])
Faculty of Informatics, Masaryk University
On Dec 17, 2007 9:45 AM, Jiri Slaby <[email protected]> wrote:
>
> You probably wanted to unregister it after _all_ cards are removed, not after
> each...
>
Hi,
thanks you are right. I haven't noticed this since spi devices are not
hot-pluggable so I could remove them only with rmmod (and so all of
them toghether). Anyway the code I sent is ugly, I will correct and
resend.
>
> Also you should synchronize_irq() after stopping them here.
>
I see. I guess I will have problems on suspending with serial activity
otherwise.
Thanks,
--
Christian Pellegrin, see http://www.evolware.org/chri/
"Real Programmers don't play tennis, or any other sport which requires
you to change clothes. Mountain climbing is OK, and Real Programmers
wear their climbing boots to work in case a mountain should suddenly
spring up in the middle of the computer room."
On 12/17/2007 09:55 AM, chri wrote:
> On Dec 17, 2007 9:45 AM, Jiri Slaby <[email protected]> wrote:
>> You probably wanted to unregister it after _all_ cards are removed, not after
>> each...
>>
>
> Hi,
>
> thanks you are right. I haven't noticed this since spi devices are not
> hot-pluggable so I could remove them only with rmmod (and so all of
> them toghether). Anyway the code I sent is ugly, I will correct and
> resend.
Won't bind/unbind in sysfs help you?
On Sat, Sep 20, 2008 at 10:24 AM, Andrew Morton
<[email protected]> wrote:
>> +#define MAX3100_MAJOR 204
>
> Allocating a new major is a Big Deal. It involves getting the major
> registered by contacting [email protected].
>
> It's better to dynamically allocate it - let udev handle it.
>
The MAX3100 is used in just small embedded systems where there is
usually no udev. I looked at other serial drivers but I haven't seen
none that uses dynamic allocation (they are share just 2 major
numbers). I followed the guide in devices.txt and asked for an
allocation of 4 minor numbers in the "Low-density serial ports".
>> +#include <linux/freezer.h>
>
> Gad. Are all those includes needed?
>
cleaned
>> +
>> +struct max3100_port_s {
>
> `struct max3100_port' is sufficient, and would be more typical.
>
done
>> + 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 */
>
> These two bits will share a word and hence locking is needed to prevent
> modifications to one from trashing modifications to the other on SMP.
>
> That's OK, but it would be best to document that locking right here, and
> to check that it is adhered to.
>
I reverted to using word aligned data.
>> + /* and it's timer */
>
> s/it's/its/
>
done. I just found the useful flyspell-prog-mode so I will drastically
reduce English errors in the patches!
>> + parity = parity ^ ((c>>i) & 1);
>
> hrmpf. Don't we have a library function for that?
>
> Perhaps you could use hweight8(c)&1.
>
done
>> + 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);
>
> <checks his C precedence table>
>
> OK...
done. Anyway I think that if precedence is unclear to me, it may be
unclear to others too; so I prefer to use a parenthesis too much than
one too few.
>> + *c &= ~MAX3100_PT;
>
> s/ / /
>
done
>
>> +}
>> +
>> +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);
>
> This is a strange place to run PREPARE_WORK(). Normally it would be
> done during driver/device initialsiation, and I think that can be done
> here.
>
done, I checked the meaning of PREPARE_WORK in the header file.
>> +
>> + etx = htons(tx);
>> + spi_message_init(&message);
>> + memset(&tran, 0, sizeof(tran));
>> + tran.tx_buf = &etx;
>> + tran.rx_buf = &erx;
>> + tran.len = 2;
>
> could do
>
> struct spi_transfer tran = {
> .tx_buf = &etx,
> .rx_buf = &erx
> .len = 2,
> };
>
> and the compiler will zero out the rest. Minor point.
>
done
>> +
>> + dev_dbg(&s->spi->dev, "%s\n", __func__);
>> +
>> + /* may not be truely up-to-date */
>
> s/truely/truly/
>
done, next time flypsell-prog-mode will help me :-)
>> +
>> + sprintf(b, "max3100-%d", s->minor);
>
> hm. This will go nasty if s->minor > 9. I'd suggest that b[] be made
> larger.
>
I limit the number of MAX3100s to 4, anyway I enlarged the buffer by
one so to be sure.
>> + 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;
>
> Shouldn't we tear down that workqueue before returning?
>
done
>> +static void max3100_release_port(struct uart_port *port)
>> +{
>> + struct max3100_port_s *s = (struct max3100_port_s *)port;
>
> container_of()
>
done
Sorry again for not replying in firs time.
--
Christian Pellegrin, see http://www.evolware.org/chri/
"Real Programmers don't play tennis, or any other sport which requires
you to change clothes. Mountain climbing is OK, and Real Programmers
wear their climbing boots to work in case a mountain should suddenly
spring up in the middle of the computer room."
On Sat, Sep 20, 2008 at 4:11 PM, Alan Cox <[email protected]> wrote:
>> +#define MAX3100_MAJOR 204
>> +#define MAX3100_MINOR 128
>> +/* 4 MAX3100s should be enough for everyone */
>> +#define MAX_MAX3100 4
>
> These need to be officially allocated if you need constant numbers
>
done, I followed the guide in devices.txt
>> +
>> + etx = htons(tx);
>
> Use cpu_to_le/be or le/be_to_cpu functions, these make the intended
> endianness clear.
>
>> + *rx = ntohs(erx);
>
> Ditto
>
done
>> + if (rxchars > 0)
>> + tty_flip_buffer_push(s->port.info->port.tty);
>> + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
>
> If there has been a hangup the port.tty will be NULL...
>
I check against NULL. But let me ask again: the other drivers (for
example SA1100) don't do it. How they avoid the nasty NULL pointer
dereference?
>> +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,
>
>> + if (!old || (termios->c_cflag != old->c_cflag)) {
>
> This optimisation is wrong and not worth doing anyway
>
done
>
> Bits you don't support should also be cleared in the tty->termios struct
> (eg markspace you don't seem to do)
>
>
done, I completely rewrote termios handling following Alan instructions.
>> + 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);
>
> Does this not then need to unregister the driver ?
>
>
I think no: perhaps it's just the probe of the second MAX3100 port
that failed so we cannot unegister the driver. And the user can try to
reprobe the MAX3100 via the bind entry. As I see it: driver
registration and port registration are 2 different things.
>
> Looks basically sound to me - just some minor cleanups needed.
>
> Alan
>
Sorry again for not having replied before resending the patch.
--
Christian Pellegrin, see http://www.evolware.org/chri/
"Real Programmers don't play tennis, or any other sport which requires
you to change clothes. Mountain climbing is OK, and Real Programmers
wear their climbing boots to work in case a mountain should suddenly
spring up in the middle of the computer room."
> > If there has been a hangup the port.tty will be NULL...
> >
>
> I check against NULL. But let me ask again: the other drivers (for
> example SA1100) don't do it. How they avoid the nasty NULL pointer
> dereference?
Some drives keep the tty pointer and deliver data to closed ttys wrongly,
others do careful locking, others are just broken.
> Sorry again for not having replied before resending the patch.
No problem