diff options
Diffstat (limited to 'drivers/tty/serial/mrst_max3110.c')
| -rw-r--r-- | drivers/tty/serial/mrst_max3110.c | 909 |
1 files changed, 0 insertions, 909 deletions
diff --git a/drivers/tty/serial/mrst_max3110.c b/drivers/tty/serial/mrst_max3110.c deleted file mode 100644 index 77239d5e620..00000000000 --- a/drivers/tty/serial/mrst_max3110.c +++ /dev/null @@ -1,909 +0,0 @@ -/* - * mrst_max3110.c - spi uart protocol driver for Maxim 3110 - * - * Copyright (c) 2008-2010, Intel Corporation. - * - * This program is free software; you can redistribute it and/or modify it - * under the terms and conditions of the GNU General Public License, - * version 2, as published by the Free Software Foundation. - * - * This program is distributed in the hope it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for - * more details. - * - * You should have received a copy of the GNU General Public License along with - * this program; if not, write to the Free Software Foundation, Inc., - * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. - */ - -/* - * Note: - * 1. From Max3110 spec, the Rx FIFO has 8 words, while the Tx FIFO only has - * 1 word. If SPI master controller doesn't support sclk frequency change, - * then the char need be sent out one by one with some delay - * - * 2. Currently only RX available interrupt is used, no need for waiting TXE - * interrupt for a low speed UART device - */ - -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt - -#ifdef CONFIG_MAGIC_SYSRQ -#define SUPPORT_SYSRQ -#endif - -#include <linux/module.h> -#include <linux/ioport.h> -#include <linux/irq.h> -#include <linux/init.h> -#include <linux/console.h> -#include <linux/tty.h> -#include <linux/tty_flip.h> -#include <linux/serial_core.h> -#include <linux/serial_reg.h> - -#include <linux/kthread.h> -#include <linux/spi/spi.h> -#include <linux/pm.h> - -#include "mrst_max3110.h" - -#define UART_TX_NEEDED 1 -#define CON_TX_NEEDED 2 -#define BIT_IRQ_PENDING 3 - -struct uart_max3110 { - struct uart_port port; - struct spi_device *spi; - char name[SPI_NAME_SIZE]; - - wait_queue_head_t wq; - struct task_struct *main_thread; - struct task_struct *read_thread; - struct mutex thread_mutex; - struct mutex io_mutex; - - u32 baud; - u16 cur_conf; - u8 clock; - u8 parity, word_7bits; - u16 irq; - - unsigned long uart_flags; - - /* console related */ - struct circ_buf con_xmit; -}; - -/* global data structure, may need be removed */ -static struct uart_max3110 *pmax; - -static int receive_chars(struct uart_max3110 *max, - unsigned short *str, int len); -static int max3110_read_multi(struct uart_max3110 *max); -static void max3110_con_receive(struct uart_max3110 *max); - -static int max3110_write_then_read(struct uart_max3110 *max, - const void *txbuf, void *rxbuf, unsigned len, int always_fast) -{ - struct spi_device *spi = max->spi; - struct spi_message message; - struct spi_transfer x; - int ret; - - mutex_lock(&max->io_mutex); - spi_message_init(&message); - memset(&x, 0, sizeof x); - x.len = len; - x.tx_buf = txbuf; - x.rx_buf = rxbuf; - spi_message_add_tail(&x, &message); - - if (always_fast) - x.speed_hz = spi->max_speed_hz; - else if (max->baud) - x.speed_hz = max->baud; - - /* Do the i/o */ - ret = spi_sync(spi, &message); - mutex_unlock(&max->io_mutex); - return ret; -} - -/* Write a 16b word to the device */ -static int max3110_out(struct uart_max3110 *max, const u16 out) -{ - void *buf; - u16 *obuf, *ibuf; - int ret; - - buf = kzalloc(8, GFP_KERNEL | GFP_DMA); - if (!buf) - return -ENOMEM; - - obuf = buf; - ibuf = buf + 4; - *obuf = out; - ret = max3110_write_then_read(max, obuf, ibuf, 2, 1); - if (ret) { - pr_warn("%s: get err msg %d when sending 0x%x\n", - __func__, ret, out); - goto exit; - } - - receive_chars(max, ibuf, 1); - -exit: - kfree(buf); - return ret; -} - -/* - * This is usually used to read data from SPIC RX FIFO, which doesn't - * need any delay like flushing character out. - * - * Return how many valide bytes are read back - */ -static int max3110_read_multi(struct uart_max3110 *max) -{ - void *buf; - u16 *obuf, *ibuf; - int ret, blen; - - blen = M3110_RX_FIFO_DEPTH * sizeof(u16); - buf = kzalloc(blen * 2, GFP_KERNEL | GFP_DMA); - if (!buf) - return 0; - - /* tx/rx always have the same length */ - obuf = buf; - ibuf = buf + blen; - - if (max3110_write_then_read(max, obuf, ibuf, blen, 1)) { - kfree(buf); - return 0; - } - - ret = receive_chars(max, ibuf, M3110_RX_FIFO_DEPTH); - - kfree(buf); - return ret; -} - -static void serial_m3110_con_putchar(struct uart_port *port, int ch) -{ - struct uart_max3110 *max = - container_of(port, struct uart_max3110, port); - struct circ_buf *xmit = &max->con_xmit; - - if (uart_circ_chars_free(xmit)) { - xmit->buf[xmit->head] = (char)ch; - xmit->head = (xmit->head + 1) & (PAGE_SIZE - 1); - } -} - -/* - * Print a string to the serial port trying not to disturb - * any possible real use of the port... - * - * The console_lock must be held when we get here. - */ -static void serial_m3110_con_write(struct console *co, - const char *s, unsigned int count) -{ - if (!pmax) - return; - - uart_console_write(&pmax->port, s, count, serial_m3110_con_putchar); - - if (!test_and_set_bit(CON_TX_NEEDED, &pmax->uart_flags)) - wake_up(&pmax->wq); -} - -static int __init -serial_m3110_con_setup(struct console *co, char *options) -{ - struct uart_max3110 *max = pmax; - int baud = 115200; - int bits = 8; - int parity = 'n'; - int flow = 'n'; - - pr_info("setting up console\n"); - - if (co->index == -1) - co->index = 0; - - if (!max) { - pr_err("pmax is NULL, return\n"); - return -ENODEV; - } - - if (options) - uart_parse_options(options, &baud, &parity, &bits, &flow); - - return uart_set_options(&max->port, co, baud, parity, bits, flow); -} - -static struct tty_driver *serial_m3110_con_device(struct console *co, - int *index) -{ - struct uart_driver *p = co->data; - *index = co->index; - return p->tty_driver; -} - -static struct uart_driver serial_m3110_reg; -static struct console serial_m3110_console = { - .name = "ttyS", - .write = serial_m3110_con_write, - .device = serial_m3110_con_device, - .setup = serial_m3110_con_setup, - .flags = CON_PRINTBUFFER, - .index = -1, - .data = &serial_m3110_reg, -}; - -static unsigned int serial_m3110_tx_empty(struct uart_port *port) -{ - return 1; -} - -static void serial_m3110_stop_tx(struct uart_port *port) -{ - return; -} - -/* stop_rx will be called in spin_lock env */ -static void serial_m3110_stop_rx(struct uart_port *port) -{ - return; -} - -#define WORDS_PER_XFER 128 -static void send_circ_buf(struct uart_max3110 *max, - struct circ_buf *xmit) -{ - void *buf; - u16 *obuf, *ibuf; - int i, len, blen, dma_size, left, ret = 0; - - - dma_size = WORDS_PER_XFER * sizeof(u16) * 2; - buf = kzalloc(dma_size, GFP_KERNEL | GFP_DMA); - if (!buf) - return; - obuf = buf; - ibuf = buf + dma_size/2; - - while (!uart_circ_empty(xmit)) { - left = uart_circ_chars_pending(xmit); - while (left) { - len = min(left, WORDS_PER_XFER); - blen = len * sizeof(u16); - memset(ibuf, 0, blen); - - for (i = 0; i < len; i++) { - obuf[i] = (u8)xmit->buf[xmit->tail] | WD_TAG; - xmit->tail = (xmit->tail + 1) & - (UART_XMIT_SIZE - 1); - } - - /* Fail to send msg to console is not very critical */ - - ret = max3110_write_then_read(max, obuf, ibuf, blen, 0); - if (ret) - pr_warn("%s: get err msg %d\n", __func__, ret); - - receive_chars(max, ibuf, len); - - max->port.icount.tx += len; - left -= len; - } - } - - kfree(buf); -} - -static void transmit_char(struct uart_max3110 *max) -{ - struct uart_port *port = &max->port; - struct circ_buf *xmit = &port->state->xmit; - - if (uart_circ_empty(xmit) || uart_tx_stopped(port)) - return; - - send_circ_buf(max, xmit); - - if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) - uart_write_wakeup(port); - - if (uart_circ_empty(xmit)) - serial_m3110_stop_tx(port); -} - -/* - * This will be called by uart_write() and tty_write, can't - * go to sleep - */ -static void serial_m3110_start_tx(struct uart_port *port) -{ - struct uart_max3110 *max = - container_of(port, struct uart_max3110, port); - - if (!test_and_set_bit(UART_TX_NEEDED, &max->uart_flags)) - wake_up(&max->wq); -} - -static int -receive_chars(struct uart_max3110 *max, unsigned short *str, int len) -{ - struct uart_port *port = &max->port; - struct tty_port *tport; - char buf[M3110_RX_FIFO_DEPTH]; - int r, w, usable; - - /* If uart is not opened, just return */ - if (!port->state) - return 0; - - tport = &port->state->port; - - for (r = 0, w = 0; r < len; r++) { - if (str[r] & MAX3110_BREAK && - uart_handle_break(port)) - continue; - - if (str[r] & MAX3110_READ_DATA_AVAILABLE) { - if (uart_handle_sysrq_char(port, str[r] & 0xff)) - continue; - - buf[w++] = str[r] & 0xff; - } - } - - if (!w) - return 0; - - for (r = 0; w; r += usable, w -= usable) { - usable = tty_buffer_request_room(tport, w); - if (usable) { - tty_insert_flip_string(tport, buf + r, usable); - port->icount.rx += usable; - } - } - tty_flip_buffer_push(tport); - - return r; -} - -/* - * This routine will be used in read_thread or RX IRQ handling, - * it will first do one round buffer read(8 words), if there is some - * valid RX data, will try to read 5 more rounds till all data - * is read out. - * - * Use stack space as data buffer to save some system load, and chose - * 504 Btyes as a threadhold to do a bulk push to upper tty layer when - * receiving bulk data, a much bigger buffer may cause stack overflow - */ -static void max3110_con_receive(struct uart_max3110 *max) -{ - int loop = 1, num; - - do { - num = max3110_read_multi(max); - - if (num) { - loop = 5; - } - } while (--loop); -} - -static int max3110_main_thread(void *_max) -{ - struct uart_max3110 *max = _max; - wait_queue_head_t *wq = &max->wq; - int ret = 0; - struct circ_buf *xmit = &max->con_xmit; - - pr_info("start main thread\n"); - - do { - wait_event_interruptible(*wq, - max->uart_flags || kthread_should_stop()); - - mutex_lock(&max->thread_mutex); - - if (test_and_clear_bit(BIT_IRQ_PENDING, &max->uart_flags)) - max3110_con_receive(max); - - /* first handle console output */ - if (test_and_clear_bit(CON_TX_NEEDED, &max->uart_flags)) - send_circ_buf(max, xmit); - - /* handle uart output */ - if (test_and_clear_bit(UART_TX_NEEDED, &max->uart_flags)) - transmit_char(max); - - mutex_unlock(&max->thread_mutex); - - } while (!kthread_should_stop()); - - return ret; -} - -static irqreturn_t serial_m3110_irq(int irq, void *dev_id) -{ - struct uart_max3110 *max = dev_id; - - /* max3110's irq is a falling edge, not level triggered, - * so no need to disable the irq */ - - if (!test_and_set_bit(BIT_IRQ_PENDING, &max->uart_flags)) - wake_up(&max->wq); - - return IRQ_HANDLED; -} - -/* if don't use RX IRQ, then need a thread to polling read */ -static int max3110_read_thread(void *_max) -{ - struct uart_max3110 *max = _max; - - pr_info("start read thread\n"); - do { - /* - * If can't acquire the mutex, it means the main thread - * is running which will also perform the rx job - */ - if (mutex_trylock(&max->thread_mutex)) { - max3110_con_receive(max); - mutex_unlock(&max->thread_mutex); - } - - set_current_state(TASK_INTERRUPTIBLE); - schedule_timeout(HZ / 20); - } while (!kthread_should_stop()); - - return 0; -} - -static int serial_m3110_startup(struct uart_port *port) -{ - struct uart_max3110 *max = - container_of(port, struct uart_max3110, port); - u16 config = 0; - int ret = 0; - - if (port->line != 0) { - pr_err("uart port startup failed\n"); - return -1; - } - - /* Disable all IRQ and config it to 115200, 8n1 */ - config = WC_TAG | WC_FIFO_ENABLE - | WC_1_STOPBITS - | WC_8BIT_WORD - | WC_BAUD_DR2; - - /* as we use thread to handle tx/rx, need set low latency */ - port->state->port.low_latency = 1; - - if (max->irq) { - /* Enable RX IRQ only */ - config |= WC_RXA_IRQ_ENABLE; - } else { - /* If IRQ is disabled, start a read thread for input data */ - max->read_thread = - kthread_run(max3110_read_thread, max, "max3110_read"); - if (IS_ERR(max->read_thread)) { - ret = PTR_ERR(max->read_thread); - max->read_thread = NULL; - pr_err("Can't create read thread!\n"); - return ret; - } - } - - ret = max3110_out(max, config); - if (ret) { - if (max->read_thread) - kthread_stop(max->read_thread); - max->read_thread = NULL; - return ret; - } - - max->cur_conf = config; - return 0; -} - -static void serial_m3110_shutdown(struct uart_port *port) -{ - struct uart_max3110 *max = - container_of(port, struct uart_max3110, port); - u16 config; - - if (max->read_thread) { - kthread_stop(max->read_thread); - max->read_thread = NULL; - } - - /* Disable interrupts from this port */ - config = WC_TAG | WC_SW_SHDI; - max3110_out(max, config); -} - -static void serial_m3110_release_port(struct uart_port *port) -{ -} - -static int serial_m3110_request_port(struct uart_port *port) -{ - return 0; -} - -static void serial_m3110_config_port(struct uart_port *port, int flags) -{ - port->type = PORT_MAX3100; -} - -static int -serial_m3110_verify_port(struct uart_port *port, struct serial_struct *ser) -{ - /* we don't want the core code to modify any port params */ - return -EINVAL; -} - - -static const char *serial_m3110_type(struct uart_port *port) -{ - struct uart_max3110 *max = - container_of(port, struct uart_max3110, port); - return max->name; -} - -static void -serial_m3110_set_termios(struct uart_port *port, struct ktermios *termios, - struct ktermios *old) -{ - struct uart_max3110 *max = - container_of(port, struct uart_max3110, port); - unsigned char cval; - unsigned int baud, parity = 0; - int clk_div = -1; - u16 new_conf = max->cur_conf; - - switch (termios->c_cflag & CSIZE) { - case CS7: - cval = UART_LCR_WLEN7; - new_conf |= WC_7BIT_WORD; - break; - default: - /* We only support CS7 & CS8 */ - termios->c_cflag &= ~CSIZE; - termios->c_cflag |= CS8; - case CS8: - cval = UART_LCR_WLEN8; - new_conf |= WC_8BIT_WORD; - break; - } - - baud = uart_get_baud_rate(port, termios, old, 0, 230400); - - /* First calc the div for 1.8MHZ clock case */ - switch (baud) { - case 300: - clk_div = WC_BAUD_DR384; - break; - case 600: - clk_div = WC_BAUD_DR192; - break; - case 1200: - clk_div = WC_BAUD_DR96; - break; - case 2400: - clk_div = WC_BAUD_DR48; - break; - case 4800: - clk_div = WC_BAUD_DR24; - break; - case 9600: - clk_div = WC_BAUD_DR12; - break; - case 19200: - clk_div = WC_BAUD_DR6; - break; - case 38400: - clk_div = WC_BAUD_DR3; - break; - case 57600: - clk_div = WC_BAUD_DR2; - break; - case 115200: - clk_div = WC_BAUD_DR1; - break; - case 230400: - if (max->clock & MAX3110_HIGH_CLK) - break; - default: - /* Pick the previous baud rate */ - baud = max->baud; - clk_div = max->cur_conf & WC_BAUD_DIV_MASK; - tty_termios_encode_baud_rate(termios, baud, baud); - } - - if (max->clock & MAX3110_HIGH_CLK) { - clk_div += 1; - /* High clk version max3110 doesn't support B300 */ - if (baud == 300) { - baud = 600; - clk_div = WC_BAUD_DR384; - } - if (baud == 230400) - clk_div = WC_BAUD_DR1; - tty_termios_encode_baud_rate(termios, baud, baud); - } - - new_conf = (new_conf & ~WC_BAUD_DIV_MASK) | clk_div; - - if (unlikely(termios->c_cflag & CMSPAR)) - termios->c_cflag &= ~CMSPAR; - - if (termios->c_cflag & CSTOPB) - new_conf |= WC_2_STOPBITS; - else - new_conf &= ~WC_2_STOPBITS; - - if (termios->c_cflag & PARENB) { - new_conf |= WC_PARITY_ENABLE; - parity |= UART_LCR_PARITY; - } else - new_conf &= ~WC_PARITY_ENABLE; - - if (!(termios->c_cflag & PARODD)) - parity |= UART_LCR_EPAR; - max->parity = parity; - - uart_update_timeout(port, termios->c_cflag, baud); - - new_conf |= WC_TAG; - if (new_conf != max->cur_conf) { - if (!max3110_out(max, new_conf)) { - max->cur_conf = new_conf; - max->baud = baud; - } - } -} - -/* Don't handle hw handshaking */ -static unsigned int serial_m3110_get_mctrl(struct uart_port *port) -{ - return TIOCM_DSR | TIOCM_CAR | TIOCM_DSR; -} - -static void serial_m3110_set_mctrl(struct uart_port *port, unsigned int mctrl) -{ -} - -static void serial_m3110_break_ctl(struct uart_port *port, int break_state) -{ -} - -static void serial_m3110_pm(struct uart_port *port, unsigned int state, - unsigned int oldstate) -{ -} - -static struct uart_ops serial_m3110_ops = { - .tx_empty = serial_m3110_tx_empty, - .set_mctrl = serial_m3110_set_mctrl, - .get_mctrl = serial_m3110_get_mctrl, - .stop_tx = serial_m3110_stop_tx, - .start_tx = serial_m3110_start_tx, - .stop_rx = serial_m3110_stop_rx, - .break_ctl = serial_m3110_break_ctl, - .startup = serial_m3110_startup, - .shutdown = serial_m3110_shutdown, - .set_termios = serial_m3110_set_termios, - .pm = serial_m3110_pm, - .type = serial_m3110_type, - .release_port = serial_m3110_release_port, - .request_port = serial_m3110_request_port, - .config_port = serial_m3110_config_port, - .verify_port = serial_m3110_verify_port, -}; - -static struct uart_driver serial_m3110_reg = { - .owner = THIS_MODULE, - .driver_name = "MRST serial", - .dev_name = "ttyS", - .major = TTY_MAJOR, - .minor = 64, - .nr = 1, - .cons = &serial_m3110_console, -}; - -#ifdef CONFIG_PM_SLEEP -static int serial_m3110_suspend(struct device *dev) -{ - struct spi_device *spi = to_spi_device(dev); - struct uart_max3110 *max = spi_get_drvdata(spi); - - if (max->irq > 0) - disable_irq(max->irq); - uart_suspend_port(&serial_m3110_reg, &max->port); - max3110_out(max, max->cur_conf | WC_SW_SHDI); - return 0; -} - -static int serial_m3110_resume(struct device *dev) -{ - struct spi_device *spi = to_spi_device(dev); - struct uart_max3110 *max = spi_get_drvdata(spi); - - max3110_out(max, max->cur_conf); - uart_resume_port(&serial_m3110_reg, &max->port); - if (max->irq > 0) - enable_irq(max->irq); - return 0; -} - -static SIMPLE_DEV_PM_OPS(serial_m3110_pm_ops, serial_m3110_suspend, - serial_m3110_resume); -#define SERIAL_M3110_PM_OPS (&serial_m3110_pm_ops) - -#else -#define SERIAL_M3110_PM_OPS NULL -#endif - -static int serial_m3110_probe(struct spi_device *spi) -{ - struct uart_max3110 *max; - void *buffer; - u16 res; - int ret = 0; - - max = kzalloc(sizeof(*max), GFP_KERNEL); - if (!max) - return -ENOMEM; - - /* Set spi info */ - spi->bits_per_word = 16; - max->clock = MAX3110_HIGH_CLK; - - spi_setup(spi); - - max->port.type = PORT_MAX3100; - max->port.fifosize = 2; /* Only have 16b buffer */ - max->port.ops = &serial_m3110_ops; - max->port.line = 0; - max->port.dev = &spi->dev; - max->port.uartclk = 115200; - - max->spi = spi; - strcpy(max->name, spi->modalias); - max->irq = (u16)spi->irq; - - mutex_init(&max->thread_mutex); - mutex_init(&max->io_mutex); - - max->word_7bits = 0; - max->parity = 0; - max->baud = 0; - - max->cur_conf = 0; - max->uart_flags = 0; - - /* Check if reading configuration register returns something sane */ - - res = RC_TAG; - ret = max3110_write_then_read(max, (u8 *)&res, (u8 *)&res, 2, 0); - if (ret < 0 || res == 0 || res == 0xffff) { - dev_dbg(&spi->dev, "MAX3111 deemed not present (conf reg %04x)", - res); - ret = -ENODEV; - goto err_get_page; - } - - buffer = (void *)__get_free_page(GFP_KERNEL); - if (!buffer) { - ret = -ENOMEM; - goto err_get_page; - } - max->con_xmit.buf = buffer; - max->con_xmit.head = 0; - max->con_xmit.tail = 0; - - init_waitqueue_head(&max->wq); - - max->main_thread = kthread_run(max3110_main_thread, - max, "max3110_main"); - if (IS_ERR(max->main_thread)) { - ret = PTR_ERR(max->main_thread); - goto err_kthread; - } - - if (max->irq) { - ret = request_irq(max->irq, serial_m3110_irq, - IRQ_TYPE_EDGE_FALLING, "max3110", max); - if (ret) { - max->irq = 0; - dev_warn(&spi->dev, - "unable to allocate IRQ, will use polling method\n"); - } - } - - spi_set_drvdata(spi, max); - pmax = max; - - /* Give membase a psudo value to pass serial_core's check */ - max->port.membase = (unsigned char __iomem *)0xff110000; - uart_add_one_port(&serial_m3110_reg, &max->port); - - return 0; - -err_kthread: - free_page((unsigned long)buffer); -err_get_page: - kfree(max); - return ret; -} - -static int serial_m3110_remove(struct spi_device *dev) -{ - struct uart_max3110 *max = spi_get_drvdata(dev); - - if (!max) - return 0; - - uart_remove_one_port(&serial_m3110_reg, &max->port); - - free_page((unsigned long)max->con_xmit.buf); - - if (max->irq) - free_irq(max->irq, max); - - if (max->main_thread) - kthread_stop(max->main_thread); - - kfree(max); - return 0; -} - -static struct spi_driver uart_max3110_driver = { - .driver = { - .name = "spi_max3111", - .owner = THIS_MODULE, - .pm = SERIAL_M3110_PM_OPS, - }, - .probe = serial_m3110_probe, - .remove = serial_m3110_remove, -}; - -static int __init serial_m3110_init(void) -{ - int ret = 0; - - ret = uart_register_driver(&serial_m3110_reg); - if (ret) - return ret; - - ret = spi_register_driver(&uart_max3110_driver); - if (ret) - uart_unregister_driver(&serial_m3110_reg); - - return ret; -} - -static void __exit serial_m3110_exit(void) -{ - spi_unregister_driver(&uart_max3110_driver); - uart_unregister_driver(&serial_m3110_reg); -} - -module_init(serial_m3110_init); -module_exit(serial_m3110_exit); - -MODULE_LICENSE("GPL v2"); -MODULE_ALIAS("spi:max3110-uart"); 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