/* * 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");