diff options
Diffstat (limited to 'drivers/serial/msm_serial.c')
| -rw-r--r-- | drivers/serial/msm_serial.c | 771 |
1 files changed, 771 insertions, 0 deletions
diff --git a/drivers/serial/msm_serial.c b/drivers/serial/msm_serial.c new file mode 100644 index 00000000000..f7c24baa141 --- /dev/null +++ b/drivers/serial/msm_serial.c @@ -0,0 +1,771 @@ +/* + * drivers/serial/msm_serial.c - driver for msm7k serial device and console + * + * Copyright (C) 2007 Google, Inc. + * Author: Robert Love <rlove@google.com> + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * This program is distributed in the hope that 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. + */ + +#if defined(CONFIG_SERIAL_MSM_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) +# define SUPPORT_SYSRQ +#endif + +#include <linux/hrtimer.h> +#include <linux/module.h> +#include <linux/io.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.h> +#include <linux/clk.h> +#include <linux/platform_device.h> + +#include "msm_serial.h" + +struct msm_port { + struct uart_port uart; + char name[16]; + struct clk *clk; + unsigned int imr; +}; + +#define UART_TO_MSM(uart_port) ((struct msm_port *) uart_port) + +static inline void msm_write(struct uart_port *port, unsigned int val, + unsigned int off) +{ + __raw_writel(val, port->membase + off); +} + +static inline unsigned int msm_read(struct uart_port *port, unsigned int off) +{ + return __raw_readl(port->membase + off); +} + +static void msm_stop_tx(struct uart_port *port) +{ + struct msm_port *msm_port = UART_TO_MSM(port); + + msm_port->imr &= ~UART_IMR_TXLEV; + msm_write(port, msm_port->imr, UART_IMR); +} + +static void msm_start_tx(struct uart_port *port) +{ + struct msm_port *msm_port = UART_TO_MSM(port); + + msm_port->imr |= UART_IMR_TXLEV; + msm_write(port, msm_port->imr, UART_IMR); +} + +static void msm_stop_rx(struct uart_port *port) +{ + struct msm_port *msm_port = UART_TO_MSM(port); + + msm_port->imr &= ~(UART_IMR_RXLEV | UART_IMR_RXSTALE); + msm_write(port, msm_port->imr, UART_IMR); +} + +static void msm_enable_ms(struct uart_port *port) +{ + struct msm_port *msm_port = UART_TO_MSM(port); + + msm_port->imr |= UART_IMR_DELTA_CTS; + msm_write(port, msm_port->imr, UART_IMR); +} + +static void handle_rx(struct uart_port *port) +{ + struct tty_struct *tty = port->info->port.tty; + unsigned int sr; + + /* + * Handle overrun. My understanding of the hardware is that overrun + * is not tied to the RX buffer, so we handle the case out of band. + */ + if ((msm_read(port, UART_SR) & UART_SR_OVERRUN)) { + port->icount.overrun++; + tty_insert_flip_char(tty, 0, TTY_OVERRUN); + msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR); + } + + /* and now the main RX loop */ + while ((sr = msm_read(port, UART_SR)) & UART_SR_RX_READY) { + unsigned int c; + char flag = TTY_NORMAL; + + c = msm_read(port, UART_RF); + + if (sr & UART_SR_RX_BREAK) { + port->icount.brk++; + if (uart_handle_break(port)) + continue; + } else if (sr & UART_SR_PAR_FRAME_ERR) { + port->icount.frame++; + } else { + port->icount.rx++; + } + + /* Mask conditions we're ignorning. */ + sr &= port->read_status_mask; + + if (sr & UART_SR_RX_BREAK) { + flag = TTY_BREAK; + } else if (sr & UART_SR_PAR_FRAME_ERR) { + flag = TTY_FRAME; + } + + if (!uart_handle_sysrq_char(port, c)) + tty_insert_flip_char(tty, c, flag); + } + + tty_flip_buffer_push(tty); +} + +static void handle_tx(struct uart_port *port) +{ + struct circ_buf *xmit = &port->info->xmit; + struct msm_port *msm_port = UART_TO_MSM(port); + int sent_tx; + + if (port->x_char) { + msm_write(port, port->x_char, UART_TF); + port->icount.tx++; + port->x_char = 0; + } + + while (msm_read(port, UART_SR) & UART_SR_TX_READY) { + if (uart_circ_empty(xmit)) { + /* disable tx interrupts */ + msm_port->imr &= ~UART_IMR_TXLEV; + msm_write(port, msm_port->imr, UART_IMR); + break; + } + + msm_write(port, xmit->buf[xmit->tail], UART_TF); + + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + port->icount.tx++; + sent_tx = 1; + } + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); +} + +static void handle_delta_cts(struct uart_port *port) +{ + msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR); + port->icount.cts++; + wake_up_interruptible(&port->info->delta_msr_wait); +} + +static irqreturn_t msm_irq(int irq, void *dev_id) +{ + struct uart_port *port = dev_id; + struct msm_port *msm_port = UART_TO_MSM(port); + unsigned int misr; + + spin_lock(&port->lock); + misr = msm_read(port, UART_MISR); + msm_write(port, 0, UART_IMR); /* disable interrupt */ + + if (misr & (UART_IMR_RXLEV | UART_IMR_RXSTALE)) + handle_rx(port); + if (misr & UART_IMR_TXLEV) + handle_tx(port); + if (misr & UART_IMR_DELTA_CTS) + handle_delta_cts(port); + + msm_write(port, msm_port->imr, UART_IMR); /* restore interrupt */ + spin_unlock(&port->lock); + + return IRQ_HANDLED; +} + +static unsigned int msm_tx_empty(struct uart_port *port) +{ + return (msm_read(port, UART_SR) & UART_SR_TX_EMPTY) ? TIOCSER_TEMT : 0; +} + +static unsigned int msm_get_mctrl(struct uart_port *port) +{ + return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR | TIOCM_RTS; +} + +static void msm_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + unsigned int mr; + + mr = msm_read(port, UART_MR1); + + if (!(mctrl & TIOCM_RTS)) { + mr &= ~UART_MR1_RX_RDY_CTL; + msm_write(port, mr, UART_MR1); + msm_write(port, UART_CR_CMD_RESET_RFR, UART_CR); + } else { + mr |= UART_MR1_RX_RDY_CTL; + msm_write(port, mr, UART_MR1); + } +} + +static void msm_break_ctl(struct uart_port *port, int break_ctl) +{ + if (break_ctl) + msm_write(port, UART_CR_CMD_START_BREAK, UART_CR); + else + msm_write(port, UART_CR_CMD_STOP_BREAK, UART_CR); +} + +static int msm_set_baud_rate(struct uart_port *port, unsigned int baud) +{ + unsigned int baud_code, rxstale, watermark; + + switch (baud) { + case 300: + baud_code = UART_CSR_300; + rxstale = 1; + break; + case 600: + baud_code = UART_CSR_600; + rxstale = 1; + break; + case 1200: + baud_code = UART_CSR_1200; + rxstale = 1; + break; + case 2400: + baud_code = UART_CSR_2400; + rxstale = 1; + break; + case 4800: + baud_code = UART_CSR_4800; + rxstale = 1; + break; + case 9600: + baud_code = UART_CSR_9600; + rxstale = 2; + break; + case 14400: + baud_code = UART_CSR_14400; + rxstale = 3; + break; + case 19200: + baud_code = UART_CSR_19200; + rxstale = 4; + break; + case 28800: + baud_code = UART_CSR_28800; + rxstale = 6; + break; + case 38400: + baud_code = UART_CSR_38400; + rxstale = 8; + break; + case 57600: + baud_code = UART_CSR_57600; + rxstale = 16; + break; + case 115200: + default: + baud_code = UART_CSR_115200; + baud = 115200; + rxstale = 31; + break; + } + + msm_write(port, baud_code, UART_CSR); + + /* RX stale watermark */ + watermark = UART_IPR_STALE_LSB & rxstale; + watermark |= UART_IPR_RXSTALE_LAST; + watermark |= UART_IPR_STALE_TIMEOUT_MSB & (rxstale << 2); + msm_write(port, watermark, UART_IPR); + + /* set RX watermark */ + watermark = (port->fifosize * 3) / 4; + msm_write(port, watermark, UART_RFWR); + + /* set TX watermark */ + msm_write(port, 10, UART_TFWR); + + return baud; +} + +static void msm_reset(struct uart_port *port) +{ + /* reset everything */ + msm_write(port, UART_CR_CMD_RESET_RX, UART_CR); + msm_write(port, UART_CR_CMD_RESET_TX, UART_CR); + msm_write(port, UART_CR_CMD_RESET_ERR, UART_CR); + msm_write(port, UART_CR_CMD_RESET_BREAK_INT, UART_CR); + msm_write(port, UART_CR_CMD_RESET_CTS, UART_CR); + msm_write(port, UART_CR_CMD_SET_RFR, UART_CR); +} + +static void msm_init_clock(struct uart_port *port) +{ + struct msm_port *msm_port = UART_TO_MSM(port); + + clk_enable(msm_port->clk); + + msm_write(port, 0xC0, UART_MREG); + msm_write(port, 0xB2, UART_NREG); + msm_write(port, 0x7D, UART_DREG); + msm_write(port, 0x1C, UART_MNDREG); +} + +static int msm_startup(struct uart_port *port) +{ + struct msm_port *msm_port = UART_TO_MSM(port); + unsigned int data, rfr_level; + int ret; + + snprintf(msm_port->name, sizeof(msm_port->name), + "msm_serial%d", port->line); + + ret = request_irq(port->irq, msm_irq, IRQF_TRIGGER_HIGH, + msm_port->name, port); + if (unlikely(ret)) + return ret; + + msm_init_clock(port); + + if (likely(port->fifosize > 12)) + rfr_level = port->fifosize - 12; + else + rfr_level = port->fifosize; + + /* set automatic RFR level */ + data = msm_read(port, UART_MR1); + data &= ~UART_MR1_AUTO_RFR_LEVEL1; + data &= ~UART_MR1_AUTO_RFR_LEVEL0; + data |= UART_MR1_AUTO_RFR_LEVEL1 & (rfr_level << 2); + data |= UART_MR1_AUTO_RFR_LEVEL0 & rfr_level; + msm_write(port, data, UART_MR1); + + /* make sure that RXSTALE count is non-zero */ + data = msm_read(port, UART_IPR); + if (unlikely(!data)) { + data |= UART_IPR_RXSTALE_LAST; + data |= UART_IPR_STALE_LSB; + msm_write(port, data, UART_IPR); + } + + msm_reset(port); + + msm_write(port, 0x05, UART_CR); /* enable TX & RX */ + + /* turn on RX and CTS interrupts */ + msm_port->imr = UART_IMR_RXLEV | UART_IMR_RXSTALE | + UART_IMR_CURRENT_CTS; + msm_write(port, msm_port->imr, UART_IMR); + + return 0; +} + +static void msm_shutdown(struct uart_port *port) +{ + struct msm_port *msm_port = UART_TO_MSM(port); + + msm_port->imr = 0; + msm_write(port, 0, UART_IMR); /* disable interrupts */ + + clk_disable(msm_port->clk); + + free_irq(port->irq, port); +} + +static void msm_set_termios(struct uart_port *port, struct ktermios *termios, + struct ktermios *old) +{ + unsigned long flags; + unsigned int baud, mr; + + spin_lock_irqsave(&port->lock, flags); + + /* calculate and set baud rate */ + baud = uart_get_baud_rate(port, termios, old, 300, 115200); + baud = msm_set_baud_rate(port, baud); + if (tty_termios_baud_rate(termios)) + tty_termios_encode_baud_rate(termios, baud, baud); + + /* calculate parity */ + mr = msm_read(port, UART_MR2); + mr &= ~UART_MR2_PARITY_MODE; + if (termios->c_cflag & PARENB) { + if (termios->c_cflag & PARODD) + mr |= UART_MR2_PARITY_MODE_ODD; + else if (termios->c_cflag & CMSPAR) + mr |= UART_MR2_PARITY_MODE_SPACE; + else + mr |= UART_MR2_PARITY_MODE_EVEN; + } + + /* calculate bits per char */ + mr &= ~UART_MR2_BITS_PER_CHAR; + switch (termios->c_cflag & CSIZE) { + case CS5: + mr |= UART_MR2_BITS_PER_CHAR_5; + break; + case CS6: + mr |= UART_MR2_BITS_PER_CHAR_6; + break; + case CS7: + mr |= UART_MR2_BITS_PER_CHAR_7; + break; + case CS8: + default: + mr |= UART_MR2_BITS_PER_CHAR_8; + break; + } + + /* calculate stop bits */ + mr &= ~(UART_MR2_STOP_BIT_LEN_ONE | UART_MR2_STOP_BIT_LEN_TWO); + if (termios->c_cflag & CSTOPB) + mr |= UART_MR2_STOP_BIT_LEN_TWO; + else + mr |= UART_MR2_STOP_BIT_LEN_ONE; + + /* set parity, bits per char, and stop bit */ + msm_write(port, mr, UART_MR2); + + /* calculate and set hardware flow control */ + mr = msm_read(port, UART_MR1); + mr &= ~(UART_MR1_CTS_CTL | UART_MR1_RX_RDY_CTL); + if (termios->c_cflag & CRTSCTS) { + mr |= UART_MR1_CTS_CTL; + mr |= UART_MR1_RX_RDY_CTL; + } + msm_write(port, mr, UART_MR1); + + /* Configure status bits to ignore based on termio flags. */ + port->read_status_mask = 0; + if (termios->c_iflag & INPCK) + port->read_status_mask |= UART_SR_PAR_FRAME_ERR; + if (termios->c_iflag & (BRKINT | PARMRK)) + port->read_status_mask |= UART_SR_RX_BREAK; + + uart_update_timeout(port, termios->c_cflag, baud); + + spin_unlock_irqrestore(&port->lock, flags); +} + +static const char *msm_type(struct uart_port *port) +{ + return "MSM"; +} + +static void msm_release_port(struct uart_port *port) +{ + struct platform_device *pdev = to_platform_device(port->dev); + struct resource *resource; + resource_size_t size; + + resource = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (unlikely(!resource)) + return; + size = resource->end - resource->start + 1; + + release_mem_region(port->mapbase, size); + iounmap(port->membase); + port->membase = NULL; +} + +static int msm_request_port(struct uart_port *port) +{ + struct platform_device *pdev = to_platform_device(port->dev); + struct resource *resource; + resource_size_t size; + + resource = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (unlikely(!resource)) + return -ENXIO; + size = resource->end - resource->start + 1; + + if (unlikely(!request_mem_region(port->mapbase, size, "msm_serial"))) + return -EBUSY; + + port->membase = ioremap(port->mapbase, size); + if (!port->membase) { + release_mem_region(port->mapbase, size); + return -EBUSY; + } + + return 0; +} + +static void msm_config_port(struct uart_port *port, int flags) +{ + if (flags & UART_CONFIG_TYPE) { + port->type = PORT_MSM; + msm_request_port(port); + } +} + +static int msm_verify_port(struct uart_port *port, struct serial_struct *ser) +{ + if (unlikely(ser->type != PORT_UNKNOWN && ser->type != PORT_MSM)) + return -EINVAL; + if (unlikely(port->irq != ser->irq)) + return -EINVAL; + return 0; +} + +static void msm_power(struct uart_port *port, unsigned int state, + unsigned int oldstate) +{ + struct msm_port *msm_port = UART_TO_MSM(port); + + switch (state) { + case 0: + clk_enable(msm_port->clk); + break; + case 3: + clk_disable(msm_port->clk); + break; + default: + printk(KERN_ERR "msm_serial: Unknown PM state %d\n", state); + } +} + +static struct uart_ops msm_uart_pops = { + .tx_empty = msm_tx_empty, + .set_mctrl = msm_set_mctrl, + .get_mctrl = msm_get_mctrl, + .stop_tx = msm_stop_tx, + .start_tx = msm_start_tx, + .stop_rx = msm_stop_rx, + .enable_ms = msm_enable_ms, + .break_ctl = msm_break_ctl, + .startup = msm_startup, + .shutdown = msm_shutdown, + .set_termios = msm_set_termios, + .type = msm_type, + .release_port = msm_release_port, + .request_port = msm_request_port, + .config_port = msm_config_port, + .verify_port = msm_verify_port, + .pm = msm_power, +}; + +static struct msm_port msm_uart_ports[] = { + { + .uart = { + .iotype = UPIO_MEM, + .ops = &msm_uart_pops, + .flags = UPF_BOOT_AUTOCONF, + .fifosize = 512, + .line = 0, + }, + }, + { + .uart = { + .iotype = UPIO_MEM, + .ops = &msm_uart_pops, + .flags = UPF_BOOT_AUTOCONF, + .fifosize = 512, + .line = 1, + }, + }, + { + .uart = { + .iotype = UPIO_MEM, + .ops = &msm_uart_pops, + .flags = UPF_BOOT_AUTOCONF, + .fifosize = 64, + .line = 2, + }, + }, +}; + +#define UART_NR ARRAY_SIZE(msm_uart_ports) + +static inline struct uart_port *get_port_from_line(unsigned int line) +{ + return &msm_uart_ports[line].uart; +} + +#ifdef CONFIG_SERIAL_MSM_CONSOLE + +static void msm_console_putchar(struct uart_port *port, int c) +{ + while (!(msm_read(port, UART_SR) & UART_SR_TX_READY)) + ; + msm_write(port, c, UART_TF); +} + +static void msm_console_write(struct console *co, const char *s, + unsigned int count) +{ + struct uart_port *port; + struct msm_port *msm_port; + + BUG_ON(co->index < 0 || co->index >= UART_NR); + + port = get_port_from_line(co->index); + msm_port = UART_TO_MSM(port); + + spin_lock(&port->lock); + uart_console_write(port, s, count, msm_console_putchar); + spin_unlock(&port->lock); +} + +static int __init msm_console_setup(struct console *co, char *options) +{ + struct uart_port *port; + int baud, flow, bits, parity; + + if (unlikely(co->index >= UART_NR || co->index < 0)) + return -ENXIO; + + port = get_port_from_line(co->index); + + if (unlikely(!port->membase)) + return -ENXIO; + + port->cons = co; + + msm_init_clock(port); + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); + + bits = 8; + parity = 'n'; + flow = 'n'; + msm_write(port, UART_MR2_BITS_PER_CHAR_8 | UART_MR2_STOP_BIT_LEN_ONE, + UART_MR2); /* 8N1 */ + + if (baud < 300 || baud > 115200) + baud = 115200; + msm_set_baud_rate(port, baud); + + msm_reset(port); + + printk(KERN_INFO "msm_serial: console setup on port #%d\n", port->line); + + return uart_set_options(port, co, baud, parity, bits, flow); +} + +static struct uart_driver msm_uart_driver; + +static struct console msm_console = { + .name = "ttyMSM", + .write = msm_console_write, + .device = uart_console_device, + .setup = msm_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &msm_uart_driver, +}; + +#define MSM_CONSOLE (&msm_console) + +#else +#define MSM_CONSOLE NULL +#endif + +static struct uart_driver msm_uart_driver = { + .owner = THIS_MODULE, + .driver_name = "msm_serial", + .dev_name = "ttyMSM", + .nr = UART_NR, + .cons = MSM_CONSOLE, +}; + +static int __init msm_serial_probe(struct platform_device *pdev) +{ + struct msm_port *msm_port; + struct resource *resource; + struct uart_port *port; + + if (unlikely(pdev->id < 0 || pdev->id >= UART_NR)) + return -ENXIO; + + printk(KERN_INFO "msm_serial: detected port #%d\n", pdev->id); + + port = get_port_from_line(pdev->id); + port->dev = &pdev->dev; + msm_port = UART_TO_MSM(port); + + msm_port->clk = clk_get(&pdev->dev, "uart_clk"); + if (unlikely(IS_ERR(msm_port->clk))) + return PTR_ERR(msm_port->clk); + port->uartclk = clk_get_rate(msm_port->clk); + + resource = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (unlikely(!resource)) + return -ENXIO; + port->mapbase = resource->start; + + port->irq = platform_get_irq(pdev, 0); + if (unlikely(port->irq < 0)) + return -ENXIO; + + platform_set_drvdata(pdev, port); + + return uart_add_one_port(&msm_uart_driver, port); +} + +static int __devexit msm_serial_remove(struct platform_device *pdev) +{ + struct msm_port *msm_port = platform_get_drvdata(pdev); + + clk_put(msm_port->clk); + + return 0; +} + +static struct platform_driver msm_platform_driver = { + .remove = msm_serial_remove, + .driver = { + .name = "msm_serial", + .owner = THIS_MODULE, + }, +}; + +static int __init msm_serial_init(void) +{ + int ret; + + ret = uart_register_driver(&msm_uart_driver); + if (unlikely(ret)) + return ret; + + ret = platform_driver_probe(&msm_platform_driver, msm_serial_probe); + if (unlikely(ret)) + uart_unregister_driver(&msm_uart_driver); + + printk(KERN_INFO "msm_serial: driver initialized\n"); + + return ret; +} + +static void __exit msm_serial_exit(void) +{ +#ifdef CONFIG_SERIAL_MSM_CONSOLE + unregister_console(&msm_console); +#endif + platform_driver_unregister(&msm_platform_driver); + uart_unregister_driver(&msm_uart_driver); +} + +module_init(msm_serial_init); +module_exit(msm_serial_exit); + +MODULE_AUTHOR("Robert Love <rlove@google.com>"); +MODULE_DESCRIPTION("Driver for msm7x serial device"); +MODULE_LICENSE("GPL"); |