diff options
Diffstat (limited to 'drivers/serial/omap-serial.c')
| -rw-r--r-- | drivers/serial/omap-serial.c | 1333 |
1 files changed, 1333 insertions, 0 deletions
diff --git a/drivers/serial/omap-serial.c b/drivers/serial/omap-serial.c new file mode 100644 index 00000000000..14365f72b66 --- /dev/null +++ b/drivers/serial/omap-serial.c @@ -0,0 +1,1333 @@ +/* + * Driver for OMAP-UART controller. + * Based on drivers/serial/8250.c + * + * Copyright (C) 2010 Texas Instruments. + * + * Authors: + * Govindraj R <govindraj.raja@ti.com> + * Thara Gopinath <thara@ti.com> + * + * 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. + * + * Note: This driver is made seperate from 8250 driver as we cannot + * over load 8250 driver with omap platform specific configuration for + * features like DMA, it makes easier to implement features like DMA and + * hardware flow control and software flow control configuration with + * this driver as required for the omap-platform. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/console.h> +#include <linux/serial_reg.h> +#include <linux/delay.h> +#include <linux/slab.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <linux/io.h> +#include <linux/dma-mapping.h> +#include <linux/clk.h> +#include <linux/serial_core.h> +#include <linux/irq.h> + +#include <plat/dma.h> +#include <plat/dmtimer.h> +#include <plat/omap-serial.h> + +static struct uart_omap_port *ui[OMAP_MAX_HSUART_PORTS]; + +/* Forward declaration of functions */ +static void uart_tx_dma_callback(int lch, u16 ch_status, void *data); +static void serial_omap_rx_timeout(unsigned long uart_no); +static int serial_omap_start_rxdma(struct uart_omap_port *up); + +static inline unsigned int serial_in(struct uart_omap_port *up, int offset) +{ + offset <<= up->port.regshift; + return readw(up->port.membase + offset); +} + +static inline void serial_out(struct uart_omap_port *up, int offset, int value) +{ + offset <<= up->port.regshift; + writew(value, up->port.membase + offset); +} + +static inline void serial_omap_clear_fifos(struct uart_omap_port *up) +{ + serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO); + serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | + UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT); + serial_out(up, UART_FCR, 0); +} + +/* + * serial_omap_get_divisor - calculate divisor value + * @port: uart port info + * @baud: baudrate for which divisor needs to be calculated. + * + * We have written our own function to get the divisor so as to support + * 13x mode. 3Mbps Baudrate as an different divisor. + * Reference OMAP TRM Chapter 17: + * Table 17-1. UART Mode Baud Rates, Divisor Values, and Error Rates + * referring to oversampling - divisor value + * baudrate 460,800 to 3,686,400 all have divisor 13 + * except 3,000,000 which has divisor value 16 + */ +static unsigned int +serial_omap_get_divisor(struct uart_port *port, unsigned int baud) +{ + unsigned int divisor; + + if (baud > OMAP_MODE13X_SPEED && baud != 3000000) + divisor = 13; + else + divisor = 16; + return port->uartclk/(baud * divisor); +} + +static void serial_omap_stop_rxdma(struct uart_omap_port *up) +{ + if (up->uart_dma.rx_dma_used) { + del_timer(&up->uart_dma.rx_timer); + omap_stop_dma(up->uart_dma.rx_dma_channel); + omap_free_dma(up->uart_dma.rx_dma_channel); + up->uart_dma.rx_dma_channel = OMAP_UART_DMA_CH_FREE; + up->uart_dma.rx_dma_used = false; + } +} + +static void serial_omap_enable_ms(struct uart_port *port) +{ + struct uart_omap_port *up = (struct uart_omap_port *)port; + + dev_dbg(up->port.dev, "serial_omap_enable_ms+%d\n", up->pdev->id); + up->ier |= UART_IER_MSI; + serial_out(up, UART_IER, up->ier); +} + +static void serial_omap_stop_tx(struct uart_port *port) +{ + struct uart_omap_port *up = (struct uart_omap_port *)port; + + if (up->use_dma && + up->uart_dma.tx_dma_channel != OMAP_UART_DMA_CH_FREE) { + /* + * Check if dma is still active. If yes do nothing, + * return. Else stop dma + */ + if (omap_get_dma_active_status(up->uart_dma.tx_dma_channel)) + return; + omap_stop_dma(up->uart_dma.tx_dma_channel); + omap_free_dma(up->uart_dma.tx_dma_channel); + up->uart_dma.tx_dma_channel = OMAP_UART_DMA_CH_FREE; + } + + if (up->ier & UART_IER_THRI) { + up->ier &= ~UART_IER_THRI; + serial_out(up, UART_IER, up->ier); + } +} + +static void serial_omap_stop_rx(struct uart_port *port) +{ + struct uart_omap_port *up = (struct uart_omap_port *)port; + + if (up->use_dma) + serial_omap_stop_rxdma(up); + up->ier &= ~UART_IER_RLSI; + up->port.read_status_mask &= ~UART_LSR_DR; + serial_out(up, UART_IER, up->ier); +} + +static inline void receive_chars(struct uart_omap_port *up, int *status) +{ + struct tty_struct *tty = up->port.state->port.tty; + unsigned int flag; + unsigned char ch, lsr = *status; + int max_count = 256; + + do { + if (likely(lsr & UART_LSR_DR)) + ch = serial_in(up, UART_RX); + flag = TTY_NORMAL; + up->port.icount.rx++; + + if (unlikely(lsr & UART_LSR_BRK_ERROR_BITS)) { + /* + * For statistics only + */ + if (lsr & UART_LSR_BI) { + lsr &= ~(UART_LSR_FE | UART_LSR_PE); + up->port.icount.brk++; + /* + * We do the SysRQ and SAK checking + * here because otherwise the break + * may get masked by ignore_status_mask + * or read_status_mask. + */ + if (uart_handle_break(&up->port)) + goto ignore_char; + } else if (lsr & UART_LSR_PE) { + up->port.icount.parity++; + } else if (lsr & UART_LSR_FE) { + up->port.icount.frame++; + } + + if (lsr & UART_LSR_OE) + up->port.icount.overrun++; + + /* + * Mask off conditions which should be ignored. + */ + lsr &= up->port.read_status_mask; + +#ifdef CONFIG_SERIAL_OMAP_CONSOLE + if (up->port.line == up->port.cons->index) { + /* Recover the break flag from console xmit */ + lsr |= up->lsr_break_flag; + up->lsr_break_flag = 0; + } +#endif + if (lsr & UART_LSR_BI) + flag = TTY_BREAK; + else if (lsr & UART_LSR_PE) + flag = TTY_PARITY; + else if (lsr & UART_LSR_FE) + flag = TTY_FRAME; + } + + if (uart_handle_sysrq_char(&up->port, ch)) + goto ignore_char; + uart_insert_char(&up->port, lsr, UART_LSR_OE, ch, flag); +ignore_char: + lsr = serial_in(up, UART_LSR); + } while ((lsr & (UART_LSR_DR | UART_LSR_BI)) && (max_count-- > 0)); + spin_unlock(&up->port.lock); + tty_flip_buffer_push(tty); + spin_lock(&up->port.lock); +} + +static void transmit_chars(struct uart_omap_port *up) +{ + struct circ_buf *xmit = &up->port.state->xmit; + int count; + + if (up->port.x_char) { + serial_out(up, UART_TX, up->port.x_char); + up->port.icount.tx++; + up->port.x_char = 0; + return; + } + if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) { + serial_omap_stop_tx(&up->port); + return; + } + count = up->port.fifosize / 4; + do { + serial_out(up, UART_TX, xmit->buf[xmit->tail]); + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + up->port.icount.tx++; + if (uart_circ_empty(xmit)) + break; + } while (--count > 0); + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(&up->port); + + if (uart_circ_empty(xmit)) + serial_omap_stop_tx(&up->port); +} + +static inline void serial_omap_enable_ier_thri(struct uart_omap_port *up) +{ + if (!(up->ier & UART_IER_THRI)) { + up->ier |= UART_IER_THRI; + serial_out(up, UART_IER, up->ier); + } +} + +static void serial_omap_start_tx(struct uart_port *port) +{ + struct uart_omap_port *up = (struct uart_omap_port *)port; + struct circ_buf *xmit; + unsigned int start; + int ret = 0; + + if (!up->use_dma) { + serial_omap_enable_ier_thri(up); + return; + } + + if (up->uart_dma.tx_dma_used) + return; + + xmit = &up->port.state->xmit; + + if (up->uart_dma.tx_dma_channel == OMAP_UART_DMA_CH_FREE) { + ret = omap_request_dma(up->uart_dma.uart_dma_tx, + "UART Tx DMA", + (void *)uart_tx_dma_callback, up, + &(up->uart_dma.tx_dma_channel)); + + if (ret < 0) { + serial_omap_enable_ier_thri(up); + return; + } + } + spin_lock(&(up->uart_dma.tx_lock)); + up->uart_dma.tx_dma_used = true; + spin_unlock(&(up->uart_dma.tx_lock)); + + start = up->uart_dma.tx_buf_dma_phys + + (xmit->tail & (UART_XMIT_SIZE - 1)); + + up->uart_dma.tx_buf_size = uart_circ_chars_pending(xmit); + /* + * It is a circular buffer. See if the buffer has wounded back. + * If yes it will have to be transferred in two separate dma + * transfers + */ + if (start + up->uart_dma.tx_buf_size >= + up->uart_dma.tx_buf_dma_phys + UART_XMIT_SIZE) + up->uart_dma.tx_buf_size = + (up->uart_dma.tx_buf_dma_phys + + UART_XMIT_SIZE) - start; + + omap_set_dma_dest_params(up->uart_dma.tx_dma_channel, 0, + OMAP_DMA_AMODE_CONSTANT, + up->uart_dma.uart_base, 0, 0); + omap_set_dma_src_params(up->uart_dma.tx_dma_channel, 0, + OMAP_DMA_AMODE_POST_INC, start, 0, 0); + omap_set_dma_transfer_params(up->uart_dma.tx_dma_channel, + OMAP_DMA_DATA_TYPE_S8, + up->uart_dma.tx_buf_size, 1, + OMAP_DMA_SYNC_ELEMENT, + up->uart_dma.uart_dma_tx, 0); + /* FIXME: Cache maintenance needed here? */ + omap_start_dma(up->uart_dma.tx_dma_channel); +} + +static unsigned int check_modem_status(struct uart_omap_port *up) +{ + unsigned int status; + + status = serial_in(up, UART_MSR); + status |= up->msr_saved_flags; + up->msr_saved_flags = 0; + if ((status & UART_MSR_ANY_DELTA) == 0) + return status; + + if (status & UART_MSR_ANY_DELTA && up->ier & UART_IER_MSI && + up->port.state != NULL) { + if (status & UART_MSR_TERI) + up->port.icount.rng++; + if (status & UART_MSR_DDSR) + up->port.icount.dsr++; + if (status & UART_MSR_DDCD) + uart_handle_dcd_change + (&up->port, status & UART_MSR_DCD); + if (status & UART_MSR_DCTS) + uart_handle_cts_change + (&up->port, status & UART_MSR_CTS); + wake_up_interruptible(&up->port.state->port.delta_msr_wait); + } + + return status; +} + +/** + * serial_omap_irq() - This handles the interrupt from one port + * @irq: uart port irq number + * @dev_id: uart port info + */ +static inline irqreturn_t serial_omap_irq(int irq, void *dev_id) +{ + struct uart_omap_port *up = dev_id; + unsigned int iir, lsr; + unsigned long flags; + + iir = serial_in(up, UART_IIR); + if (iir & UART_IIR_NO_INT) + return IRQ_NONE; + + spin_lock_irqsave(&up->port.lock, flags); + lsr = serial_in(up, UART_LSR); + if (iir & UART_IIR_RLSI) { + if (!up->use_dma) { + if (lsr & UART_LSR_DR) + receive_chars(up, &lsr); + } else { + up->ier &= ~(UART_IER_RDI | UART_IER_RLSI); + serial_out(up, UART_IER, up->ier); + if ((serial_omap_start_rxdma(up) != 0) && + (lsr & UART_LSR_DR)) + receive_chars(up, &lsr); + } + } + + check_modem_status(up); + if ((lsr & UART_LSR_THRE) && (iir & UART_IIR_THRI)) + transmit_chars(up); + + spin_unlock_irqrestore(&up->port.lock, flags); + up->port_activity = jiffies; + return IRQ_HANDLED; +} + +static unsigned int serial_omap_tx_empty(struct uart_port *port) +{ + struct uart_omap_port *up = (struct uart_omap_port *)port; + unsigned long flags = 0; + unsigned int ret = 0; + + dev_dbg(up->port.dev, "serial_omap_tx_empty+%d\n", up->pdev->id); + spin_lock_irqsave(&up->port.lock, flags); + ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0; + spin_unlock_irqrestore(&up->port.lock, flags); + + return ret; +} + +static unsigned int serial_omap_get_mctrl(struct uart_port *port) +{ + struct uart_omap_port *up = (struct uart_omap_port *)port; + unsigned char status; + unsigned int ret = 0; + + status = check_modem_status(up); + dev_dbg(up->port.dev, "serial_omap_get_mctrl+%d\n", up->pdev->id); + + if (status & UART_MSR_DCD) + ret |= TIOCM_CAR; + if (status & UART_MSR_RI) + ret |= TIOCM_RNG; + if (status & UART_MSR_DSR) + ret |= TIOCM_DSR; + if (status & UART_MSR_CTS) + ret |= TIOCM_CTS; + return ret; +} + +static void serial_omap_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + struct uart_omap_port *up = (struct uart_omap_port *)port; + unsigned char mcr = 0; + + dev_dbg(up->port.dev, "serial_omap_set_mctrl+%d\n", up->pdev->id); + if (mctrl & TIOCM_RTS) + mcr |= UART_MCR_RTS; + if (mctrl & TIOCM_DTR) + mcr |= UART_MCR_DTR; + if (mctrl & TIOCM_OUT1) + mcr |= UART_MCR_OUT1; + if (mctrl & TIOCM_OUT2) + mcr |= UART_MCR_OUT2; + if (mctrl & TIOCM_LOOP) + mcr |= UART_MCR_LOOP; + + mcr |= up->mcr; + serial_out(up, UART_MCR, mcr); +} + +static void serial_omap_break_ctl(struct uart_port *port, int break_state) +{ + struct uart_omap_port *up = (struct uart_omap_port *)port; + unsigned long flags = 0; + + dev_dbg(up->port.dev, "serial_omap_break_ctl+%d\n", up->pdev->id); + spin_lock_irqsave(&up->port.lock, flags); + if (break_state == -1) + up->lcr |= UART_LCR_SBC; + else + up->lcr &= ~UART_LCR_SBC; + serial_out(up, UART_LCR, up->lcr); + spin_unlock_irqrestore(&up->port.lock, flags); +} + +static int serial_omap_startup(struct uart_port *port) +{ + struct uart_omap_port *up = (struct uart_omap_port *)port; + unsigned long flags = 0; + int retval; + + /* + * Allocate the IRQ + */ + retval = request_irq(up->port.irq, serial_omap_irq, up->port.irqflags, + up->name, up); + if (retval) + return retval; + + dev_dbg(up->port.dev, "serial_omap_startup+%d\n", up->pdev->id); + + /* + * Clear the FIFO buffers and disable them. + * (they will be reenabled in set_termios()) + */ + serial_omap_clear_fifos(up); + /* For Hardware flow control */ + serial_out(up, UART_MCR, UART_MCR_RTS); + + /* + * Clear the interrupt registers. + */ + (void) serial_in(up, UART_LSR); + if (serial_in(up, UART_LSR) & UART_LSR_DR) + (void) serial_in(up, UART_RX); + (void) serial_in(up, UART_IIR); + (void) serial_in(up, UART_MSR); + + /* + * Now, initialize the UART + */ + serial_out(up, UART_LCR, UART_LCR_WLEN8); + spin_lock_irqsave(&up->port.lock, flags); + /* + * Most PC uarts need OUT2 raised to enable interrupts. + */ + up->port.mctrl |= TIOCM_OUT2; + serial_omap_set_mctrl(&up->port, up->port.mctrl); + spin_unlock_irqrestore(&up->port.lock, flags); + + up->msr_saved_flags = 0; + if (up->use_dma) { + free_page((unsigned long)up->port.state->xmit.buf); + up->port.state->xmit.buf = dma_alloc_coherent(NULL, + UART_XMIT_SIZE, + (dma_addr_t *)&(up->uart_dma.tx_buf_dma_phys), + 0); + init_timer(&(up->uart_dma.rx_timer)); + up->uart_dma.rx_timer.function = serial_omap_rx_timeout; + up->uart_dma.rx_timer.data = up->pdev->id; + /* Currently the buffer size is 4KB. Can increase it */ + up->uart_dma.rx_buf = dma_alloc_coherent(NULL, + up->uart_dma.rx_buf_size, + (dma_addr_t *)&(up->uart_dma.rx_buf_dma_phys), 0); + } + /* + * Finally, enable interrupts. Note: Modem status interrupts + * are set via set_termios(), which will be occurring imminently + * anyway, so we don't enable them here. + */ + up->ier = UART_IER_RLSI | UART_IER_RDI; + serial_out(up, UART_IER, up->ier); + + up->port_activity = jiffies; + return 0; +} + +static void serial_omap_shutdown(struct uart_port *port) +{ + struct uart_omap_port *up = (struct uart_omap_port *)port; + unsigned long flags = 0; + + dev_dbg(up->port.dev, "serial_omap_shutdown+%d\n", up->pdev->id); + /* + * Disable interrupts from this port + */ + up->ier = 0; + serial_out(up, UART_IER, 0); + + spin_lock_irqsave(&up->port.lock, flags); + up->port.mctrl &= ~TIOCM_OUT2; + serial_omap_set_mctrl(&up->port, up->port.mctrl); + spin_unlock_irqrestore(&up->port.lock, flags); + + /* + * Disable break condition and FIFOs + */ + serial_out(up, UART_LCR, serial_in(up, UART_LCR) & ~UART_LCR_SBC); + serial_omap_clear_fifos(up); + + /* + * Read data port to reset things, and then free the irq + */ + if (serial_in(up, UART_LSR) & UART_LSR_DR) + (void) serial_in(up, UART_RX); + if (up->use_dma) { + dma_free_coherent(up->port.dev, + UART_XMIT_SIZE, up->port.state->xmit.buf, + up->uart_dma.tx_buf_dma_phys); + up->port.state->xmit.buf = NULL; + serial_omap_stop_rx(port); + dma_free_coherent(up->port.dev, + up->uart_dma.rx_buf_size, up->uart_dma.rx_buf, + up->uart_dma.rx_buf_dma_phys); + up->uart_dma.rx_buf = NULL; + } + free_irq(up->port.irq, up); +} + +static inline void +serial_omap_configure_xonxoff + (struct uart_omap_port *up, struct ktermios *termios) +{ + unsigned char efr = 0; + + up->lcr = serial_in(up, UART_LCR); + serial_out(up, UART_LCR, OMAP_UART_LCR_CONF_MDB); + up->efr = serial_in(up, UART_EFR); + serial_out(up, UART_EFR, up->efr & ~UART_EFR_ECB); + + serial_out(up, UART_XON1, termios->c_cc[VSTART]); + serial_out(up, UART_XOFF1, termios->c_cc[VSTOP]); + + /* clear SW control mode bits */ + efr = up->efr; + efr &= OMAP_UART_SW_CLR; + + /* + * IXON Flag: + * Enable XON/XOFF flow control on output. + * Transmit XON1, XOFF1 + */ + if (termios->c_iflag & IXON) + efr |= OMAP_UART_SW_TX; + + /* + * IXOFF Flag: + * Enable XON/XOFF flow control on input. + * Receiver compares XON1, XOFF1. + */ + if (termios->c_iflag & IXOFF) + efr |= OMAP_UART_SW_RX; + + serial_out(up, UART_EFR, up->efr | UART_EFR_ECB); + serial_out(up, UART_LCR, UART_LCR_DLAB); + + up->mcr = serial_in(up, UART_MCR); + + /* + * IXANY Flag: + * Enable any character to restart output. + * Operation resumes after receiving any + * character after recognition of the XOFF character + */ + if (termios->c_iflag & IXANY) + up->mcr |= UART_MCR_XONANY; + + serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR); + serial_out(up, UART_LCR, OMAP_UART_LCR_CONF_MDB); + serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG); + /* Enable special char function UARTi.EFR_REG[5] and + * load the new software flow control mode IXON or IXOFF + * and restore the UARTi.EFR_REG[4] ENHANCED_EN value. + */ + serial_out(up, UART_EFR, efr | UART_EFR_SCD); + serial_out(up, UART_LCR, UART_LCR_DLAB); + + serial_out(up, UART_MCR, up->mcr & ~UART_MCR_TCRTLR); + serial_out(up, UART_LCR, up->lcr); +} + +static void +serial_omap_set_termios(struct uart_port *port, struct ktermios *termios, + struct ktermios *old) +{ + struct uart_omap_port *up = (struct uart_omap_port *)port; + unsigned char cval = 0; + unsigned char efr = 0; + unsigned long flags = 0; + unsigned int baud, quot; + + switch (termios->c_cflag & CSIZE) { + case CS5: + cval = UART_LCR_WLEN5; + break; + case CS6: + cval = UART_LCR_WLEN6; + break; + case CS7: + cval = UART_LCR_WLEN7; + break; + default: + case CS8: + cval = UART_LCR_WLEN8; + break; + } + + if (termios->c_cflag & CSTOPB) + cval |= UART_LCR_STOP; + if (termios->c_cflag & PARENB) + cval |= UART_LCR_PARITY; + if (!(termios->c_cflag & PARODD)) + cval |= UART_LCR_EPAR; + + /* + * Ask the core to calculate the divisor for us. + */ + + baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/13); + quot = serial_omap_get_divisor(port, baud); + + up->fcr = UART_FCR_R_TRIG_01 | UART_FCR_T_TRIG_01 | + UART_FCR_ENABLE_FIFO; + if (up->use_dma) + up->fcr |= UART_FCR_DMA_SELECT; + + /* + * Ok, we're now changing the port state. Do it with + * interrupts disabled. + */ + spin_lock_irqsave(&up->port.lock, flags); + + /* + * Update the per-port timeout. + */ + uart_update_timeout(port, termios->c_cflag, baud); + + up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR; + if (termios->c_iflag & INPCK) + up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE; + if (termios->c_iflag & (BRKINT | PARMRK)) + up->port.read_status_mask |= UART_LSR_BI; + + /* + * Characters to ignore + */ + up->port.ignore_status_mask = 0; + if (termios->c_iflag & IGNPAR) + up->port.ignore_status_mask |= UART_LSR_PE | UART_LSR_FE; + if (termios->c_iflag & IGNBRK) { + up->port.ignore_status_mask |= UART_LSR_BI; + /* + * If we're ignoring parity and break indicators, + * ignore overruns too (for real raw support). + */ + if (termios->c_iflag & IGNPAR) + up->port.ignore_status_mask |= UART_LSR_OE; + } + + /* + * ignore all characters if CREAD is not set + */ + if ((termios->c_cflag & CREAD) == 0) + up->port.ignore_status_mask |= UART_LSR_DR; + + /* + * Modem status interrupts + */ + up->ier &= ~UART_IER_MSI; + if (UART_ENABLE_MS(&up->port, termios->c_cflag)) + up->ier |= UART_IER_MSI; + serial_out(up, UART_IER, up->ier); + serial_out(up, UART_LCR, cval); /* reset DLAB */ + + /* FIFOs and DMA Settings */ + + /* FCR can be changed only when the + * baud clock is not running + * DLL_REG and DLH_REG set to 0. + */ + serial_out(up, UART_LCR, UART_LCR_DLAB); + serial_out(up, UART_DLL, 0); + serial_out(up, UART_DLM, 0); + serial_out(up, UART_LCR, 0); + + serial_out(up, UART_LCR, OMAP_UART_LCR_CONF_MDB); + + up->efr = serial_in(up, UART_EFR); + serial_out(up, UART_EFR, up->efr | UART_EFR_ECB); + + serial_out(up, UART_LCR, UART_LCR_DLAB); + up->mcr = serial_in(up, UART_MCR); + serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR); + /* FIFO ENABLE, DMA MODE */ + serial_out(up, UART_FCR, up->fcr); + serial_out(up, UART_LCR, OMAP_UART_LCR_CONF_MDB); + + if (up->use_dma) { + serial_out(up, UART_TI752_TLR, 0); + serial_out(up, UART_OMAP_SCR, + (UART_FCR_TRIGGER_4 | UART_FCR_TRIGGER_8)); + } + + serial_out(up, UART_EFR, up->efr); + serial_out(up, UART_LCR, UART_LCR_DLAB); + serial_out(up, UART_MCR, up->mcr); + + /* Protocol, Baud Rate, and Interrupt Settings */ + + serial_out(up, UART_OMAP_MDR1, OMAP_MDR1_DISABLE); + serial_out(up, UART_LCR, OMAP_UART_LCR_CONF_MDB); + + up->efr = serial_in(up, UART_EFR); + serial_out(up, UART_EFR, up->efr | UART_EFR_ECB); + + serial_out(up, UART_LCR, 0); + serial_out(up, UART_IER, 0); + serial_out(up, UART_LCR, OMAP_UART_LCR_CONF_MDB); + + serial_out(up, UART_DLL, quot & 0xff); /* LS of divisor */ + serial_out(up, UART_DLM, quot >> 8); /* MS of divisor */ + + serial_out(up, UART_LCR, 0); + serial_out(up, UART_IER, up->ier); + serial_out(up, UART_LCR, OMAP_UART_LCR_CONF_MDB); + + serial_out(up, UART_EFR, up->efr); + serial_out(up, UART_LCR, cval); + + if (baud > 230400 && baud != 3000000) + serial_out(up, UART_OMAP_MDR1, OMAP_MDR1_MODE13X); + else + serial_out(up, UART_OMAP_MDR1, OMAP_MDR1_MODE16X); + + /* Hardware Flow Control Configuration */ + + if (termios->c_cflag & CRTSCTS) { + efr |= (UART_EFR_CTS | UART_EFR_RTS); + serial_out(up, UART_LCR, UART_LCR_DLAB); + + up->mcr = serial_in(up, UART_MCR); + serial_out(up, UART_MCR, up->mcr | UART_MCR_TCRTLR); + + serial_out(up, UART_LCR, OMAP_UART_LCR_CONF_MDB); + up->efr = serial_in(up, UART_EFR); + serial_out(up, UART_EFR, up->efr | UART_EFR_ECB); + + serial_out(up, UART_TI752_TCR, OMAP_UART_TCR_TRIG); + serial_out(up, UART_EFR, efr); /* Enable AUTORTS and AUTOCTS */ + serial_out(up, UART_LCR, UART_LCR_DLAB); + serial_out(up, UART_MCR, up->mcr | UART_MCR_RTS); + serial_out(up, UART_LCR, cval); + } + + serial_omap_set_mctrl(&up->port, up->port.mctrl); + /* Software Flow Control Configuration */ + if (termios->c_iflag & (IXON | IXOFF)) + serial_omap_configure_xonxoff(up, termios); + + spin_unlock_irqrestore(&up->port.lock, flags); + dev_dbg(up->port.dev, "serial_omap_set_termios+%d\n", up->pdev->id); +} + +static void +serial_omap_pm(struct uart_port *port, unsigned int state, + unsigned int oldstate) +{ + struct uart_omap_port *up = (struct uart_omap_port *)port; + unsigned char efr; + + dev_dbg(up->port.dev, "serial_omap_pm+%d\n", up->pdev->id); + serial_out(up, UART_LCR, OMAP_UART_LCR_CONF_MDB); + efr = serial_in(up, UART_EFR); + serial_out(up, UART_EFR, efr | UART_EFR_ECB); + serial_out(up, UART_LCR, 0); + + serial_out(up, UART_IER, (state != 0) ? UART_IERX_SLEEP : 0); + serial_out(up, UART_LCR, OMAP_UART_LCR_CONF_MDB); + serial_out(up, UART_EFR, efr); + serial_out(up, UART_LCR, 0); + /* Enable module level wake up */ + serial_out(up, UART_OMAP_WER, + (state != 0) ? OMAP_UART_WER_MOD_WKUP : 0); +} + +static void serial_omap_release_port(struct uart_port *port) +{ + dev_dbg(port->dev, "serial_omap_release_port+\n"); +} + +static int serial_omap_request_port(struct uart_port *port) +{ + dev_dbg(port->dev, "serial_omap_request_port+\n"); + return 0; +} + +static void serial_omap_config_port(struct uart_port *port, int flags) +{ + struct uart_omap_port *up = (struct uart_omap_port *)port; + + dev_dbg(up->port.dev, "serial_omap_config_port+%d\n", + up->pdev->id); + up->port.type = PORT_OMAP; +} + +static int +serial_omap_verify_port(struct uart_port *port, struct serial_struct *ser) +{ + /* we don't want the core code to modify any port params */ + dev_dbg(port->dev, "serial_omap_verify_port+\n"); + return -EINVAL; +} + +static const char * +serial_omap_type(struct uart_port *port) +{ + struct uart_omap_port *up = (struct uart_omap_port *)port; + + dev_dbg(up->port.dev, "serial_omap_type+%d\n", up->pdev->id); + return up->name; +} + +#ifdef CONFIG_SERIAL_OMAP_CONSOLE + +static struct uart_omap_port *serial_omap_console_ports[4]; + +static struct uart_driver serial_omap_reg; + +#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE) + +static inline void wait_for_xmitr(struct uart_omap_port *up) +{ + unsigned int status, tmout = 10000; + + /* Wait up to 10ms for the character(s) to be sent. */ + do { + status = serial_in(up, UART_LSR); + + if (status & UART_LSR_BI) + up->lsr_break_flag = UART_LSR_BI; + + if (--tmout == 0) + break; + udelay(1); + } while ((status & BOTH_EMPTY) != BOTH_EMPTY); + + /* Wait up to 1s for flow control if necessary */ + if (up->port.flags & UPF_CONS_FLOW) { + tmout = 1000000; + for (tmout = 1000000; tmout; tmout--) { + unsigned int msr = serial_in(up, UART_MSR); + + up->msr_saved_flags |= msr & MSR_SAVE_FLAGS; + if (msr & UART_MSR_CTS) + break; + + udelay(1); + } + } +} + +static void serial_omap_console_putchar(struct uart_port *port, int ch) +{ + struct uart_omap_port *up = (struct uart_omap_port *)port; + + wait_for_xmitr(up); + serial_out(up, UART_TX, ch); +} + +static void +serial_omap_console_write(struct console *co, const char *s, + unsigned int count) +{ + struct uart_omap_port *up = serial_omap_console_ports[co->index]; + unsigned long flags; + unsigned int ier; + int locked = 1; + + local_irq_save(flags); + if (up->port.sysrq) + locked = 0; + else if (oops_in_progress) + locked = spin_trylock(&up->port.lock); + else + spin_lock(&up->port.lock); + + /* + * First save the IER then disable the interrupts + */ + ier = serial_in(up, UART_IER); + serial_out(up, UART_IER, 0); + + uart_console_write(&up->port, s, count, serial_omap_console_putchar); + + /* + * Finally, wait for transmitter to become empty + * and restore the IER + */ + wait_for_xmitr(up); + serial_out(up, UART_IER, ier); + /* + * The receive handling will happen properly because the + * receive ready bit will still be set; it is not cleared + * on read. However, modem control will not, we must + * call it if we have saved something in the saved flags + * while processing with interrupts off. + */ + if (up->msr_saved_flags) + check_modem_status(up); + + if (locked) + spin_unlock(&up->port.lock); + local_irq_restore(flags); +} + +static int __init +serial_omap_console_setup(struct console *co, char *options) +{ + struct uart_omap_port *up; + int baud = 115200; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + + if (serial_omap_console_ports[co->index] == NULL) + return -ENODEV; + up = serial_omap_console_ports[co->index]; + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); + + return uart_set_options(&up->port, co, baud, parity, bits, flow); +} + +static struct console serial_omap_console = { + .name = OMAP_SERIAL_NAME, + .write = serial_omap_console_write, + .device = uart_console_device, + .setup = serial_omap_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &serial_omap_reg, +}; + +static void serial_omap_add_console_port(struct uart_omap_port *up) +{ + serial_omap_console_ports[up->pdev->id] = up; +} + +#define OMAP_CONSOLE (&serial_omap_console) + +#else + +#define OMAP_CONSOLE NULL + +static inline void serial_omap_add_console_port(struct uart_omap_port *up) +{} + +#endif + +static struct uart_ops serial_omap_pops = { + .tx_empty = serial_omap_tx_empty, + .set_mctrl = serial_omap_set_mctrl, + .get_mctrl = serial_omap_get_mctrl, + .stop_tx = serial_omap_stop_tx, + .start_tx = serial_omap_start_tx, + .stop_rx = serial_omap_stop_rx, + .enable_ms = serial_omap_enable_ms, + .break_ctl = serial_omap_break_ctl, + .startup = serial_omap_startup, + .shutdown = serial_omap_shutdown, + .set_termios = serial_omap_set_termios, + .pm = serial_omap_pm, + .type = serial_omap_type, + .release_port = serial_omap_release_port, + .request_port = serial_omap_request_port, + .config_port = serial_omap_config_port, + .verify_port = serial_omap_verify_port, +}; + +static struct uart_driver serial_omap_reg = { + .owner = THIS_MODULE, + .driver_name = "OMAP-SERIAL", + .dev_name = OMAP_SERIAL_NAME, + .nr = OMAP_MAX_HSUART_PORTS, + .cons = OMAP_CONSOLE, +}; + +static int +serial_omap_suspend(struct platform_device *pdev, pm_message_t state) +{ + struct uart_omap_port *up = platform_get_drvdata(pdev); + + if (up) + uart_suspend_port(&serial_omap_reg, &up->port); + return 0; +} + +static int serial_omap_resume(struct platform_device *dev) +{ + struct uart_omap_port *up = platform_get_drvdata(dev); + + if (up) + uart_resume_port(&serial_omap_reg, &up->port); + return 0; +} + +static void serial_omap_rx_timeout(unsigned long uart_no) +{ + struct uart_omap_port *up = ui[uart_no]; + unsigned int curr_dma_pos, curr_transmitted_size; + int ret = 0; + + curr_dma_pos = omap_get_dma_dst_pos(up->uart_dma.rx_dma_channel); + if ((curr_dma_pos == up->uart_dma.prev_rx_dma_pos) || + (curr_dma_pos == 0)) { + if (jiffies_to_msecs(jiffies - up->port_activity) < + RX_TIMEOUT) { + mod_timer(&up->uart_dma.rx_timer, jiffies + + usecs_to_jiffies(up->uart_dma.rx_timeout)); + } else { + serial_omap_stop_rxdma(up); + up->ier |= (UART_IER_RDI | UART_IER_RLSI); + serial_out(up, UART_IER, up->ier); + } + return; + } + + curr_transmitted_size = curr_dma_pos - + up->uart_dma.prev_rx_dma_pos; + up->port.icount.rx += curr_transmitted_size; + tty_insert_flip_string(up->port.state->port.tty, + up->uart_dma.rx_buf + + (up->uart_dma.prev_rx_dma_pos - + up->uart_dma.rx_buf_dma_phys), + curr_transmitted_size); + tty_flip_buffer_push(up->port.state->port.tty); + up->uart_dma.prev_rx_dma_pos = curr_dma_pos; + if (up->uart_dma.rx_buf_size + + up->uart_dma.rx_buf_dma_phys == curr_dma_pos) { + ret = serial_omap_start_rxdma(up); + if (ret < 0) { + serial_omap_stop_rxdma(up); + up->ier |= (UART_IER_RDI | UART_IER_RLSI); + serial_out(up, UART_IER, up->ier); + } + } else { + mod_timer(&up->uart_dma.rx_timer, jiffies + + usecs_to_jiffies(up->uart_dma.rx_timeout)); + } + up->port_activity = jiffies; +} + +static void uart_rx_dma_callback(int lch, u16 ch_status, void *data) +{ + return; +} + +static int serial_omap_start_rxdma(struct uart_omap_port *up) +{ + int ret = 0; + + if (up->uart_dma.rx_dma_channel == -1) { + ret = omap_request_dma(up->uart_dma.uart_dma_rx, + "UART Rx DMA", + (void *)uart_rx_dma_callback, up, + &(up->uart_dma.rx_dma_channel)); + if (ret < 0) + return ret; + + omap_set_dma_src_params(up->uart_dma.rx_dma_channel, 0, + OMAP_DMA_AMODE_CONSTANT, + up->uart_dma.uart_base, 0, 0); + omap_set_dma_dest_params(up->uart_dma.rx_dma_channel, 0, + OMAP_DMA_AMODE_POST_INC, + up->uart_dma.rx_buf_dma_phys, 0, 0); + omap_set_dma_transfer_params(up->uart_dma.rx_dma_channel, + OMAP_DMA_DATA_TYPE_S8, + up->uart_dma.rx_buf_size, 1, + OMAP_DMA_SYNC_ELEMENT, + up->uart_dma.uart_dma_rx, 0); + } + up->uart_dma.prev_rx_dma_pos = up->uart_dma.rx_buf_dma_phys; + /* FIXME: Cache maintenance needed here? */ + omap_start_dma(up->uart_dma.rx_dma_channel); + mod_timer(&up->uart_dma.rx_timer, jiffies + + usecs_to_jiffies(up->uart_dma.rx_timeout)); + up->uart_dma.rx_dma_used = true; + return ret; +} + +static void serial_omap_continue_tx(struct uart_omap_port *up) +{ + struct circ_buf *xmit = &up->port.state->xmit; + unsigned int start = up->uart_dma.tx_buf_dma_phys + + (xmit->tail & (UART_XMIT_SIZE - 1)); + + if (uart_circ_empty(xmit)) + return; + + up->uart_dma.tx_buf_size = uart_circ_chars_pending(xmit); + /* + * It is a circular buffer. See if the buffer has wounded back. + * If yes it will have to be transferred in two separate dma + * transfers + */ + if (start + up->uart_dma.tx_buf_size >= + up->uart_dma.tx_buf_dma_phys + UART_XMIT_SIZE) + up->uart_dma.tx_buf_size = + (up->uart_dma.tx_buf_dma_phys + UART_XMIT_SIZE) - start; + omap_set_dma_dest_params(up->uart_dma.tx_dma_channel, 0, + OMAP_DMA_AMODE_CONSTANT, + up->uart_dma.uart_base, 0, 0); + omap_set_dma_src_params(up->uart_dma.tx_dma_channel, 0, + OMAP_DMA_AMODE_POST_INC, start, 0, 0); + omap_set_dma_transfer_params(up->uart_dma.tx_dma_channel, + OMAP_DMA_DATA_TYPE_S8, + up->uart_dma.tx_buf_size, 1, + OMAP_DMA_SYNC_ELEMENT, + up->uart_dma.uart_dma_tx, 0); + /* FIXME: Cache maintenance needed here? */ + omap_start_dma(up->uart_dma.tx_dma_channel); +} + +static void uart_tx_dma_callback(int lch, u16 ch_status, void *data) +{ + struct uart_omap_port *up = (struct uart_omap_port *)data; + struct circ_buf *xmit = &up->port.state->xmit; + + xmit->tail = (xmit->tail + up->uart_dma.tx_buf_size) & \ + (UART_XMIT_SIZE - 1); + up->port.icount.tx += up->uart_dma.tx_buf_size; + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(&up->port); + + if (uart_circ_empty(xmit)) { + spin_lock(&(up->uart_dma.tx_lock)); + serial_omap_stop_tx(&up->port); + up->uart_dma.tx_dma_used = false; + spin_unlock(&(up->uart_dma.tx_lock)); + } else { + omap_stop_dma(up->uart_dma.tx_dma_channel); + serial_omap_continue_tx(up); + } + up->port_activity = jiffies; + return; +} + +static int serial_omap_probe(struct platform_device *pdev) +{ + struct uart_omap_port *up; + struct resource *mem, *irq, *dma_tx, *dma_rx; + struct omap_uart_port_info *omap_up_info = pdev->dev.platform_data; + int ret = -ENOSPC; + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!mem) { + dev_err(&pdev->dev, "no mem resource?\n"); + return -ENODEV; + } + + irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + if (!irq) { + dev_err(&pdev->dev, "no irq resource?\n"); + return -ENODEV; + } + + if (!request_mem_region(mem->start, (mem->end - mem->start) + 1, + pdev->dev.driver->name)) { + dev_err(&pdev->dev, "memory region already claimed\n"); + return -EBUSY; + } + + dma_rx = platform_get_resource_byname(pdev, IORESOURCE_DMA, "rx"); + if (!dma_rx) { + ret = -EINVAL; + goto err; + } + + dma_tx = platform_get_resource_byname(pdev, IORESOURCE_DMA, "tx"); + if (!dma_tx) { + ret = -EINVAL; + goto err; + } + + up = kzalloc(sizeof(*up), GFP_KERNEL); + if (up == NULL) { + ret = -ENOMEM; + goto do_release_region; + } + sprintf(up->name, "OMAP UART%d", pdev->id); + up->pdev = pdev; + up->port.dev = &pdev->dev; + up->port.type = PORT_OMAP; + up->port.iotype = UPIO_MEM; + up->port.irq = irq->start; + + up->port.regshift = 2; + up->port.fifosize = 64; + up->port.ops = &serial_omap_pops; + up->port.line = pdev->id; + + up->port.membase = omap_up_info->membase; + up->port.mapbase = omap_up_info->mapbase; + up->port.flags = omap_up_info->flags; + up->port.irqflags = omap_up_info->irqflags; + up->port.uartclk = omap_up_info->uartclk; + up->uart_dma.uart_base = mem->start; + + if (omap_up_info->dma_enabled) { + up->uart_dma.uart_dma_tx = dma_tx->start; + up->uart_dma.uart_dma_rx = dma_rx->start; + up->use_dma = 1; + up->uart_dma.rx_buf_size = 4096; + up->uart_dma.rx_timeout = 2; + spin_lock_init(&(up->uart_dma.tx_lock)); + spin_lock_init(&(up->uart_dma.rx_lock)); + up->uart_dma.tx_dma_channel = OMAP_UART_DMA_CH_FREE; + up->uart_dma.rx_dma_channel = OMAP_UART_DMA_CH_FREE; + } + + ui[pdev->id] = up; + serial_omap_add_console_port(up); + + ret = uart_add_one_port(&serial_omap_reg, &up->port); + if (ret != 0) + goto do_release_region; + + platform_set_drvdata(pdev, up); + return 0; +err: + dev_err(&pdev->dev, "[UART%d]: failure [%s]: %d\n", + pdev->id, __func__, ret); +do_release_region: + release_mem_region(mem->start, (mem->end - mem->start) + 1); + return ret; +} + +static int serial_omap_remove(struct platform_device *dev) +{ + struct uart_omap_port *up = platform_get_drvdata(dev); + + platform_set_drvdata(dev, NULL); + if (up) { + uart_remove_one_port(&serial_omap_reg, &up->port); + kfree(up); + } + return 0; +} + +static struct platform_driver serial_omap_driver = { + .probe = serial_omap_probe, + .remove = serial_omap_remove, + + .suspend = serial_omap_suspend, + .resume = serial_omap_resume, + .driver = { + .name = DRIVER_NAME, + }, +}; + +static int __init serial_omap_init(void) +{ + int ret; + + ret = uart_register_driver(&serial_omap_reg); + if (ret != 0) + return ret; + ret = platform_driver_register(&serial_omap_driver); + if (ret != 0) + uart_unregister_driver(&serial_omap_reg); + return ret; +} + +static void __exit serial_omap_exit(void) +{ + platform_driver_unregister(&serial_omap_driver); + uart_unregister_driver(&serial_omap_reg); +} + +module_init(serial_omap_init); +module_exit(serial_omap_exit); + +MODULE_DESCRIPTION("OMAP High Speed UART driver"); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Texas Instruments Inc"); |