diff options
| -rw-r--r-- | drivers/serial/max3100.c | 927 | ||||
| -rw-r--r-- | include/linux/serial_max3100.h | 52 |
2 files changed, 979 insertions, 0 deletions
diff --git a/drivers/serial/max3100.c b/drivers/serial/max3100.c new file mode 100644 index 000000000000..9fd33e5622bd --- /dev/null +++ b/drivers/serial/max3100.c @@ -0,0 +1,927 @@ +/* + * + * 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, + .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 209 in the low-density serial port: + * mknod /dev/ttyMAX0 c 204 209 + */ + +#define MAX3100_MAJOR 204 +#define MAX3100_MINOR 209 +/* 4 MAX3100s should be enough for everyone */ +#define MAX_MAX3100 4 + +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/serial_core.h> +#include <linux/serial.h> +#include <linux/spi/spi.h> +#include <linux/freezer.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 { + struct uart_port port; + struct spi_device *spi; + + int cts; /* last CTS received for flow ctrl */ + int tx_empty; /* last TX empty bit */ + + spinlock_t conf_lock; /* shared data */ + int conf_commit; /* need to make changes */ + int conf; /* configuration for the MAX31000 + * (bits 0-7, bits 8-11 are irqs) */ + int rts_commit; /* need to change rts */ + int rts; /* rts status */ + int baud; /* current baud rate */ + + int parity; /* keeps track if we should send parity */ +#define MAX3100_PARITY_ON 1 +#define MAX3100_PARITY_ODD 2 +#define MAX3100_7BIT 4 + int rx_enabled; /* if we should rx chars */ + + 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 */ + + /* 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; + /* need to know we are suspending to avoid deadlock on workqueue */ + int suspending; + + /* hook for suspending MAX3100 via dedicated pin */ + void (*max3100_hw_suspend) (int suspend); + + /* poll time (in ms) for ctrl lines */ + int poll_time; + /* and its timer */ + struct timer_list timer; +}; + +static struct max3100_port *max3100s[MAX_MAX3100]; /* the chips */ +static DEFINE_MUTEX(max3100s_lock); /* race on probe */ + +static int max3100_do_parity(struct max3100_port *s, u16 c) +{ + int parity; + + if (s->parity & MAX3100_PARITY_ODD) + parity = 1; + else + parity = 0; + + if (s->parity & MAX3100_7BIT) + c &= 0x7f; + else + c &= 0xff; + + parity = parity ^ (hweight8(c) & 1); + return parity; +} + +static int max3100_check_parity(struct max3100_port *s, u16 c) +{ + return max3100_do_parity(s, c) == ((c >> 8) & 1); +} + +static void max3100_calc_parity(struct max3100_port *s, u16 *c) +{ + if (s->parity & MAX3100_7BIT) + *c &= 0x7f; + else + *c &= 0xff; + + 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) +{ + if (!s->force_end_work && !work_pending(&s->work) && + !freezing(current) && !s->suspending) + queue_work(s->workqueue, &s->work); +} + +static void max3100_timeout(unsigned long data) +{ + struct max3100_port *s = (struct max3100_port *)data; + + if (s->port.info) { + max3100_dowork(s); + mod_timer(&s->timer, jiffies + s->poll_time); + } +} + +static int max3100_sr(struct max3100_port *s, u16 tx, u16 *rx) +{ + struct spi_message message; + u16 etx, erx; + int status; + struct spi_transfer tran = { + .tx_buf = &etx, + .rx_buf = &erx, + .len = 2, + }; + + etx = cpu_to_be16(tx); + spi_message_init(&message); + 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 = be16_to_cpu(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, 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 = container_of(w, struct max3100_port, 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__); + + rxchars = 0; + do { + 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 > 16 && s->port.info->port.tty != NULL) { + tty_flip_buffer_push(s->port.info->port.tty); + rxchars = 0; + } + 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 (rxchars > 0 && s->port.info->port.tty != NULL) + tty_flip_buffer_push(s->port.info->port.tty); +} + +static irqreturn_t max3100_irq(int irqno, void *dev_id) +{ + struct max3100_port *s = dev_id; + + dev_dbg(&s->spi->dev, "%s\n", __func__); + + max3100_dowork(s); + return IRQ_HANDLED; +} + +static void max3100_enable_ms(struct uart_port *port) +{ + struct max3100_port *s = container_of(port, + struct max3100_port, + 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 = container_of(port, + struct max3100_port, + 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 = container_of(port, + struct max3100_port, + 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 = container_of(port, + struct max3100_port, + port); + + dev_dbg(&s->spi->dev, "%s\n", __func__); + + /* may not be truly up-to-date */ + max3100_dowork(s); + return s->tx_empty; +} + +static unsigned int max3100_get_mctrl(struct uart_port *port) +{ + struct max3100_port *s = container_of(port, + struct max3100_port, + port); + + dev_dbg(&s->spi->dev, "%s\n", __func__); + + /* may not be truly 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 = container_of(port, + struct max3100_port, + 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 = container_of(port, + struct max3100_port, + port); + int baud = 0; + unsigned cflag; + u32 param_new, param_mask, parity = 0; + struct tty_struct *tty = s->port.info->port.tty; + + dev_dbg(&s->spi->dev, "%s\n", __func__); + if (!tty) + return; + + cflag = termios->c_cflag; + param_new = 0; + param_mask = 0; + + baud = tty_get_baud_rate(tty); + param_new = s->conf & MAX3100_BAUD; + switch (baud) { + case 300: + if (s->crystal) + baud = s->baud; + else + param_new = 15; + break; + case 600: + param_new = 14 + s->crystal; + break; + case 1200: + param_new = 13 + s->crystal; + break; + case 2400: + param_new = 12 + s->crystal; + break; + case 4800: + param_new = 11 + s->crystal; + break; + case 9600: + param_new = 10 + s->crystal; + break; + case 19200: + param_new = 9 + s->crystal; + break; + case 38400: + param_new = 8 + s->crystal; + break; + case 57600: + param_new = 1 + s->crystal; + break; + case 115200: + param_new = 0 + s->crystal; + break; + case 230400: + if (s->crystal) + param_new = 0; + else + baud = s->baud; + break; + default: + baud = s->baud; + } + tty_encode_baud_rate(tty, baud, baud); + s->baud = baud; + param_mask |= MAX3100_BAUD; + + if ((cflag & CSIZE) == CS8) { + param_new &= ~MAX3100_L; + parity &= ~MAX3100_7BIT; + } else { + param_new |= MAX3100_L; + parity |= MAX3100_7BIT; + cflag = (cflag & ~CSIZE) | CS7; + } + 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; + + /* mask termios capabilities we don't support */ + cflag &= ~CMSPAR; + termios->c_cflag = cflag; + + 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; + + /* we are sending char from a workqueue so enable */ + s->port.info->port.tty->low_latency = 1; + + 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 = container_of(port, + struct max3100_port, + 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); + s->workqueue = NULL; + } + 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 = container_of(port, + struct max3100_port, + port); + char b[12]; + + dev_dbg(&s->spi->dev, "%s\n", __func__); + + s->conf = MAX3100_RM; + s->baud = s->crystal ? 230400 : 115200; + 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); + + if (request_irq(s->irq, max3100_irq, + IRQF_TRIGGER_FALLING, "max3100", s) < 0) { + dev_warn(&s->spi->dev, "cannot allocate irq %d\n", s->irq); + s->irq = 0; + destroy_workqueue(s->workqueue); + s->workqueue = NULL; + 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 = container_of(port, + struct max3100_port, + 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 = container_of(port, + struct max3100_port, + port); + + dev_dbg(&s->spi->dev, "%s\n", __func__); +} + +static void max3100_config_port(struct uart_port *port, int flags) +{ + struct max3100_port *s = container_of(port, + struct max3100_port, + 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 = container_of(port, + struct max3100_port, + 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 = container_of(port, + struct max3100_port, + port); + + dev_dbg(&s->spi->dev, "%s\n", __func__); +} + +static int max3100_request_port(struct uart_port *port) +{ + struct max3100_port *s = container_of(port, + struct max3100_port, + 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 = container_of(port, + struct max3100_port, + 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; + + mutex_lock(&max3100s_lock); + + 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"); + mutex_unlock(&max3100s_lock); + 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"); + mutex_unlock(&max3100s_lock); + return -ENOMEM; + } + + max3100s[i] = kzalloc(sizeof(struct max3100_port), GFP_KERNEL); + if (!max3100s[i]) { + dev_warn(&spi->dev, + "kmalloc for max3100 structure %d failed!\n", i); + mutex_unlock(&max3100s_lock); + 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]->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); + } + mutex_unlock(&max3100s_lock); + return 0; +} + +static int __devexit max3100_remove(struct spi_device *spi) +{ + struct max3100_port *s = dev_get_drvdata(&spi->dev); + int i; + + mutex_lock(&max3100s_lock); + + /* 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]) { + mutex_unlock(&max3100s_lock); + return 0; + } + pr_debug("removing max3100 driver\n"); + uart_unregister_driver(&max3100_uart_driver); + + mutex_unlock(&max3100s_lock); + return 0; +} + +#ifdef CONFIG_PM + +static int max3100_suspend(struct spi_device *spi, pm_message_t state) +{ + struct max3100_port *s = dev_get_drvdata(&spi->dev); + + dev_dbg(&s->spi->dev, "%s\n", __func__); + + disable_irq(s->irq); + + s->suspending = 1; + uart_suspend_port(&max3100_uart_driver, &s->port); + + 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 = dev_get_drvdata(&spi->dev); + + dev_dbg(&s->spi->dev, "%s\n", __func__); + + if (s->max3100_hw_suspend) + s->max3100_hw_suspend(0); + uart_resume_port(&max3100_uart_driver, &s->port); + s->suspending = 0; + + enable_irq(s->irq); + + s->conf_commit = 1; + if (s->workqueue) + max3100_dowork(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_AUTHOR("Christian Pellegrin <chripell@evolware.org>"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/serial_max3100.h b/include/linux/serial_max3100.h new file mode 100644 index 000000000000..4976befb6aeb --- /dev/null +++ b/include/linux/serial_max3100.h @@ -0,0 +1,52 @@ +/* + * + * 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 - MAX3100 SPI UART platform data + * @loopback: force MAX3100 in loopback + * @crystal: 1 for 3.6864 Mhz, 0 for 1.8432 + * @max3100_hw_suspend: MAX3100 has a shutdown pin. This is a hook + * called on suspend and resume to activate it. + * @poll_time: poll time for CTS signal in ms, 0 disables (so no hw + * flow ctrl is possible but you have less CPU usage) + * + * You should use this structure in your machine description to specify + * how the MAX3100 is connected. Example: + * + * static struct plat_max3100 max3100_plat_data = { + * .loopback = 0, + * .crystal = 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, + * }, + * }; + * + **/ +struct plat_max3100 { + int loopback; + int crystal; + void (*max3100_hw_suspend) (int suspend); + int poll_time; +}; + +#endif |