/* * Driver for OMAP-UART controller. * Based on drivers/serial/8250.c * * Copyright (C) 2010 Texas Instruments. * * Authors: * Govindraj R * Thara Gopinath * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include 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; unsigned 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");