diff options
Diffstat (limited to 'drivers/serial/mxc_uart.c')
| -rw-r--r-- | drivers/serial/mxc_uart.c | 1957 |
1 files changed, 1957 insertions, 0 deletions
diff --git a/drivers/serial/mxc_uart.c b/drivers/serial/mxc_uart.c new file mode 100644 index 000000000000..347a7462c396 --- /dev/null +++ b/drivers/serial/mxc_uart.c @@ -0,0 +1,1957 @@ +/* + * Copyright 2004-2010 Freescale Semiconductor, Inc. All Rights Reserved. + */ + +/* + * The code contained herein is licensed under the GNU General Public + * License. You may obtain a copy of the GNU General Public License + * Version 2 or later at the following locations: + * + * http://www.opensource.org/licenses/gpl-license.html + * http://www.gnu.org/copyleft/gpl.html + */ + +/*! + * @file drivers/serial/mxc_uart.c + * + * @brief Driver for the Freescale Semiconductor MXC serial ports based on + * drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. + * + * @ingroup UART + */ + +/* + * Include Files + */ +#include <linux/module.h> +#include <linux/interrupt.h> +#include <linux/tty.h> +#include <linux/string.h> +#include <linux/ioport.h> +#include <linux/init.h> +#include <linux/serial.h> +#include <linux/console.h> +#include <linux/platform_device.h> +#include <linux/sysrq.h> +#include <linux/dma-mapping.h> +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/slab.h> +#include <asm/irq.h> +#include <asm/dma.h> +#include <asm/div64.h> +#include <mach/mxc_uart.h> + +#if defined(CONFIG_SERIAL_MXC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) +#define SUPPORT_SYSRQ +#endif +#define SERIAL_MXC_MAJOR 207 +#define SERIAL_MXC_MINOR 16 +#define MXC_ISR_PASS_LIMIT 256 +#define UART_CREAD_BIT 256 + +#define MXC_UART_NR 8 + +/* IRDA minimum pulse duration in micro seconds */ +#define MIN_PULSE_DUR 2 +/* + * Transmit DMA buffer size is set to 1024 bytes, this is limited + * by UART_XMIT_SIZE. + */ +#define TXDMA_BUFF_SIZE UART_XMIT_SIZE +/* + * Receive DMA sub-buffer size + */ +#define RXDMA_BUFF_SIZE 128 + +/*! + * This structure is used to store the information for DMA data transfer. + */ +typedef struct { + /*! + * Holds the read channel number. + */ + int rd_channel; + /*! + * Holds the write channel number. + */ + int wr_channel; + /*! + * UART Transmit Event ID + */ + int tx_event_id; + /*! + * UART Receive Event ID + */ + int rx_event_id; + /*! + * DMA Transmit tasklet + */ + struct tasklet_struct dma_tx_tasklet; + /*! + * Flag indicates if the channel is in use + */ + int dma_txchnl_inuse; +} dma_info; + +/*! + * This is used to indicate if we want echo cancellation in the Irda mode. + */ +static int echo_cancel; +extern void gpio_uart_active(int port, int no_irda); +extern void gpio_uart_inactive(int port, int no_irda); +extern void config_uartdma_event(int port); + +static uart_mxc_port *mxc_ports[MXC_UART_NR]; + +/*! + * This array holds the DMA channel information for each MXC UART + */ +static dma_info dma_list[MXC_UART_NR]; + +/*! + * This function is called by the core driver to stop UART transmission. + * This might be due to the TTY layer indicating that the user wants to stop + * transmission. + * + * @param port the port structure for the UART passed in by the core + * driver + */ +static void mxcuart_stop_tx(struct uart_port *port) +{ + uart_mxc_port *umxc = (uart_mxc_port *) port; + volatile unsigned int cr1; + + cr1 = readl(port->membase + MXC_UARTUCR1); + /* Disable Transmitter rdy interrupt */ + if (umxc->dma_enabled == 1) { + cr1 &= ~MXC_UARTUCR1_TXDMAEN; + } else { + cr1 &= ~MXC_UARTUCR1_TRDYEN; + } + writel(cr1, port->membase + MXC_UARTUCR1); +} + +/*! + * DMA Transmit tasklet method is scheduled on completion of a DMA transmit + * to send out any more data that is available in the UART xmit buffer. + * + * @param arg driver private data + */ +static void dma_tx_do_tasklet(unsigned long arg) +{ + uart_mxc_port *umxc = (uart_mxc_port *) arg; + struct circ_buf *xmit = &umxc->port.state->xmit; + mxc_dma_requestbuf_t writechnl_request; + int tx_num; + unsigned long flags; + + spin_lock_irqsave(&umxc->port.lock, flags); + tx_num = uart_circ_chars_pending(xmit); + if (tx_num > 0) { + if (xmit->tail > xmit->head) { + memcpy(umxc->tx_buf, xmit->buf + xmit->tail, + UART_XMIT_SIZE - xmit->tail); + memcpy(umxc->tx_buf + (UART_XMIT_SIZE - xmit->tail), + xmit->buf, xmit->head); + } else { + memcpy(umxc->tx_buf, xmit->buf + xmit->tail, tx_num); + } + umxc->tx_handle = dma_map_single(umxc->port.dev, umxc->tx_buf, + TXDMA_BUFF_SIZE, + DMA_TO_DEVICE); + + writechnl_request.dst_addr = umxc->port.mapbase + MXC_UARTUTXD; + writechnl_request.src_addr = umxc->tx_handle; + writechnl_request.num_of_bytes = tx_num; + + if ((mxc_dma_config(dma_list[umxc->port.line].wr_channel, + &writechnl_request, 1, + MXC_DMA_MODE_WRITE)) == 0) { + mxc_dma_enable(dma_list[umxc->port.line].wr_channel); + } + } else { + /* No more data available in the xmit queue, clear the flag */ + dma_list[umxc->port.line].dma_txchnl_inuse = 0; + } + spin_unlock_irqrestore(&umxc->port.lock, flags); +} + +/*! + * DMA Write callback is called by the SDMA controller after it has sent out all + * the data from the user buffer. This function updates the xmit buffer pointers. + * + * @param arg driver private data + * @param error any DMA error + * @param count amount of data that was transferred + */ +static void mxcuart_dma_writecallback(void *arg, int error, unsigned int count) +{ + uart_mxc_port *umxc = arg; + struct circ_buf *xmit = &umxc->port.state->xmit; + int tx_num; + + if (error != MXC_DMA_TRANSFER_ERROR) { + tx_num = count; + umxc->port.icount.tx += tx_num; + xmit->tail = (xmit->tail + tx_num) & (UART_XMIT_SIZE - 1); + } + + dma_unmap_single(umxc->port.dev, umxc->tx_handle, TXDMA_BUFF_SIZE, + DMA_TO_DEVICE); + tx_num = uart_circ_chars_pending(xmit); + /* Schedule a tasklet to send out the pending characters */ + if (tx_num > 0) { + tasklet_schedule(&dma_list[umxc->port.line].dma_tx_tasklet); + } else { + dma_list[umxc->port.line].dma_txchnl_inuse = 0; + } + if (tx_num < WAKEUP_CHARS) { + uart_write_wakeup(&umxc->port); + } +} + +/*! + * This function is called by the core driver to start transmitting characters. + * This function enables the transmit interrupts. + * + * @param port the port structure for the UART passed in by the core + * driver + */ +static void mxcuart_start_tx(struct uart_port *port) +{ + uart_mxc_port *umxc = (uart_mxc_port *) port; + struct circ_buf *xmit = &umxc->port.state->xmit; + volatile unsigned int cr1; + mxc_dma_requestbuf_t writechnl_request; + int tx_num; + + cr1 = readl(port->membase + MXC_UARTUCR1); + /* Enable Transmitter rdy interrupt */ + if (umxc->dma_enabled == 1) { + /* + * If the channel is in use then return immediately and use + * the dma_tx tasklet to transfer queued data when current DMA + * transfer is complete + */ + if (dma_list[umxc->port.line].dma_txchnl_inuse == 1) { + return; + } + tx_num = uart_circ_chars_pending(xmit); + if (tx_num > 0) { + dma_list[umxc->port.line].dma_txchnl_inuse = 1; + if (xmit->tail > xmit->head) { + memcpy(umxc->tx_buf, xmit->buf + xmit->tail, + UART_XMIT_SIZE - xmit->tail); + memcpy(umxc->tx_buf + + (UART_XMIT_SIZE - xmit->tail), xmit->buf, + xmit->head); + } else { + memcpy(umxc->tx_buf, xmit->buf + xmit->tail, + tx_num); + } + umxc->tx_handle = + dma_map_single(umxc->port.dev, umxc->tx_buf, + TXDMA_BUFF_SIZE, DMA_TO_DEVICE); + + writechnl_request.dst_addr = + umxc->port.mapbase + MXC_UARTUTXD; + writechnl_request.src_addr = umxc->tx_handle; + writechnl_request.num_of_bytes = tx_num; + if ((mxc_dma_config + (dma_list[umxc->port.line].wr_channel, + &writechnl_request, 1, + MXC_DMA_MODE_WRITE)) == 0) { + mxc_dma_enable(dma_list[umxc->port.line]. + wr_channel); + } + cr1 |= MXC_UARTUCR1_TXDMAEN; + } + } else { + cr1 |= MXC_UARTUCR1_TRDYEN; + } + writel(cr1, port->membase + MXC_UARTUCR1); +} + +/*! + * This function is called by the core driver to stop receiving characters; the + * port is in the process of being closed. + * + * @param port the port structure for the UART passed in by the core driver + */ +static void mxcuart_stop_rx(struct uart_port *port) +{ + uart_mxc_port *umxc = (uart_mxc_port *) port; + volatile unsigned int cr1; + + cr1 = readl(port->membase + MXC_UARTUCR1); + if (umxc->dma_enabled == 1) { + cr1 &= ~MXC_UARTUCR1_RXDMAEN; + } else { + cr1 &= ~MXC_UARTUCR1_RRDYEN; + } + writel(cr1, port->membase + MXC_UARTUCR1); +} + +/*! + * This function is called by the core driver to enable the modem status + * interrupts. If the port is configured to be in DTE mode then it enables the + * DCDDELT and RIDELT interrupts in addition to the DTRDEN interrupt. The RTSDEN + * interrupt is enabled only for interrupt-driven hardware flow control. + * + * @param port the port structure for the UART passed in by the core driver + */ +static void mxcuart_enable_ms(struct uart_port *port) +{ + uart_mxc_port *umxc = (uart_mxc_port *) port; + volatile unsigned int cr1, cr3; + + /* + * RTS interrupt is enabled only if we are using interrupt-driven + * software controlled hardware flow control + */ + if (umxc->hardware_flow == 0) { + cr1 = readl(umxc->port.membase + MXC_UARTUCR1); + cr1 |= MXC_UARTUCR1_RTSDEN; + writel(cr1, umxc->port.membase + MXC_UARTUCR1); + } + cr3 = readl(umxc->port.membase + MXC_UARTUCR3); + cr3 |= MXC_UARTUCR3_DTRDEN; + if (umxc->mode == MODE_DTE) { + cr3 |= MXC_UARTUCR3_DCD | MXC_UARTUCR3_RI; + } + writel(cr3, umxc->port.membase + MXC_UARTUCR3); +} + +/*! + * This function is called from the interrupt service routine if the status bit + * indicates that the receive fifo data level is above the set threshold. The + * function reads the character and queues them into the TTY layers read + * buffer. The function also looks for break characters, parity and framing + * errors in the received character and sets the appropriate flag in the TTY + * receive buffer. + * + * @param umxc the MXC UART port structure, this includes the \b uart_port + * structure and other members that are specific to MXC UARTs + */ +static void mxcuart_rx_chars(uart_mxc_port *umxc) +{ + volatile unsigned int ch, sr2; + unsigned int status, flag, max_count = 256; + + sr2 = readl(umxc->port.membase + MXC_UARTUSR2); + while (((sr2 & MXC_UARTUSR2_RDR) == 1) && (max_count-- > 0)) { + ch = readl(umxc->port.membase + MXC_UARTURXD); + + flag = TTY_NORMAL; + status = ch | UART_CREAD_BIT; + ch &= 0xFF; /* Clear the upper bits */ + umxc->port.icount.rx++; + + /* + * Check to see if there is an error in the received + * character. Perform the appropriate actions based on the + * error bit that was set. + */ + if (status & MXC_UARTURXD_ERR) { + if (status & MXC_UARTURXD_BRK) { + /* + * Clear the frame and parity error bits + * as these always get set on receiving a + * break character + */ + status &= ~(MXC_UARTURXD_FRMERR | + MXC_UARTURXD_PRERR); + umxc->port.icount.brk++; + if (uart_handle_break(&umxc->port)) { + goto ignore_char; + } + } else if (status & MXC_UARTURXD_FRMERR) { + umxc->port.icount.frame++; + } else if (status & MXC_UARTURXD_PRERR) { + umxc->port.icount.parity++; + } + if (status & MXC_UARTURXD_OVRRUN) { + umxc->port.icount.overrun++; + } + + status &= umxc->port.read_status_mask; + + if (status & MXC_UARTURXD_BRK) { + flag = TTY_BREAK; + } else if (status & MXC_UARTURXD_FRMERR) { + flag = TTY_FRAME; + } else if (status & MXC_UARTURXD_PRERR) { + flag = TTY_PARITY; + } + } + + if (uart_handle_sysrq_char(&umxc->port, ch)) { + goto ignore_char; + } + + uart_insert_char(&umxc->port, status, MXC_UARTURXD_OVRRUN, ch, + flag); + ignore_char: + sr2 = readl(umxc->port.membase + MXC_UARTUSR2); + } + tty_flip_buffer_push(umxc->port.state->port.tty); +} + +/*! + * This function is called from the interrupt service routine if the status bit + * indicates that the transmit fifo is emptied below its set threshold and + * requires data. The function pulls characters from the TTY layers write + * buffer and writes it out to the UART transmit fifo. + * + * @param umxc the MXC UART port structure, this includes the \b uart_port + * structure and other members that are specific to MXC UARTs + */ +static void mxcuart_tx_chars(uart_mxc_port *umxc) +{ + struct circ_buf *xmit = &umxc->port.state->xmit; + int count; + + /* + * Transmit the XON/XOFF character if required + */ + if (umxc->port.x_char) { + writel(umxc->port.x_char, umxc->port.membase + MXC_UARTUTXD); + umxc->port.icount.tx++; + umxc->port.x_char = 0; + return; + } + + /* + * Check to see if there is any data to be sent and that the + * port has not been currently stopped by anything. + */ + if (uart_circ_empty(xmit) || uart_tx_stopped(&umxc->port)) { + mxcuart_stop_tx(&umxc->port); + return; + } + + count = umxc->port.fifosize - umxc->tx_threshold; + do { + writel(xmit->buf[xmit->tail], + umxc->port.membase + MXC_UARTUTXD); + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + umxc->port.icount.tx++; + if (uart_circ_empty(xmit)) { + break; + } + } while (--count > 0); + + /* + * Check to see if we have flushed enough characters to ask for more + * to be sent to us, if so, we notify the user space that we can + * accept more data + */ + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) { + uart_write_wakeup(&umxc->port); + } + + if (uart_circ_empty(xmit)) { + mxcuart_stop_tx(&umxc->port); + } +} + +/*! + * This function is called from the interrupt service routine if there is a + * change in the modem signals. This function handles these signal changes and + * also clears the appropriate status register bits. + * + * @param umxc the MXC UART port structure, this includes the \b uart_port + * structure and other members that are specific to MXC UARTs + * @param sr1 contents of status register 1 + * @param sr2 contents of status register 2 + */ +static void mxcuart_modem_status(uart_mxc_port *umxc, unsigned int sr1, + unsigned int sr2) +{ + if (umxc->mode == MODE_DTE) { + if (sr2 & MXC_UARTUSR2_DCDDELT) { + uart_handle_dcd_change(&umxc->port, + !(sr2 & MXC_UARTUSR2_DCDIN)); + } + if (sr2 & MXC_UARTUSR2_RIDELT) { + umxc->port.icount.rng++; + } + } + if (sr1 & MXC_UARTUSR1_DTRD) { + umxc->port.icount.dsr++; + } + if ((umxc->hardware_flow == 0) && (sr1 & MXC_UARTUSR1_RTSD)) { + uart_handle_cts_change(&umxc->port, sr1 & MXC_UARTUSR1_RTSS); + } + + wake_up_interruptible(&umxc->port.state->port.delta_msr_wait); +} + +/*! + * Interrupt service routine registered to handle the muxed ANDed interrupts. + * This routine is registered only in the case where the UART interrupts are + * muxed. + * + * @param irq the interrupt number + * @param dev_id driver private data + * + * @return The function returns \b IRQ_RETVAL(1) if interrupt was handled, + * returns \b IRQ_RETVAL(0) if the interrupt was not handled. + * \b IRQ_RETVAL is defined in \b include/linux/interrupt.h. + */ +static irqreturn_t mxcuart_int(int irq, void *dev_id) +{ + uart_mxc_port *umxc = dev_id; + volatile unsigned int sr1, sr2, cr1, cr; + unsigned int pass_counter = MXC_ISR_PASS_LIMIT; + unsigned int term_cond = 0; + int handled = 0; + + sr1 = readl(umxc->port.membase + MXC_UARTUSR1); + sr2 = readl(umxc->port.membase + MXC_UARTUSR2); + cr1 = readl(umxc->port.membase + MXC_UARTUCR1); + + do { + /* Clear the bits that triggered the interrupt */ + writel(sr1, umxc->port.membase + MXC_UARTUSR1); + writel(sr2, umxc->port.membase + MXC_UARTUSR2); + /* + * Read if there is data available + */ + if (sr2 & MXC_UARTUSR2_RDR) { + mxcuart_rx_chars(umxc); + } + + if ((sr1 & (MXC_UARTUSR1_RTSD | MXC_UARTUSR1_DTRD)) || + (sr2 & (MXC_UARTUSR2_DCDDELT | MXC_UARTUSR2_RIDELT))) { + mxcuart_modem_status(umxc, sr1, sr2); + } + + /* + * Send data if there is data to be sent + */ + if ((cr1 & MXC_UARTUCR1_TRDYEN) && (sr1 & MXC_UARTUSR1_TRDY)) { + /* Echo cancellation for IRDA Transmit chars */ + if (umxc->ir_mode == IRDA && echo_cancel) { + /* Disable the receiver */ + cr = readl(umxc->port.membase + MXC_UARTUCR2); + cr &= ~MXC_UARTUCR2_RXEN; + writel(cr, umxc->port.membase + MXC_UARTUCR2); + /* Enable Transmit complete intr to reenable RX */ + cr = readl(umxc->port.membase + MXC_UARTUCR4); + cr |= MXC_UARTUCR4_TCEN; + writel(cr, umxc->port.membase + MXC_UARTUCR4); + } + mxcuart_tx_chars(umxc); + } + + if (pass_counter-- == 0) { + break; + } + + sr1 = readl(umxc->port.membase + MXC_UARTUSR1); + sr2 = readl(umxc->port.membase + MXC_UARTUSR2); + + /* Is the transmit complete to reenable the receiver? */ + if (umxc->ir_mode == IRDA && echo_cancel) { + if (sr2 & MXC_UARTUSR2_TXDC) { + cr = readl(umxc->port.membase + MXC_UARTUCR2); + cr |= MXC_UARTUCR2_RXEN; + writel(cr, umxc->port.membase + MXC_UARTUCR2); + /* Disable the Transmit complete interrupt bit */ + cr = readl(umxc->port.membase + MXC_UARTUCR4); + cr &= ~MXC_UARTUCR4_TCEN; + writel(cr, umxc->port.membase + MXC_UARTUCR4); + } + } + + /* + * If there is no data to send or receive and if there is no + * change in the modem status signals then quit the routine + */ + term_cond = sr1 & (MXC_UARTUSR1_RTSD | MXC_UARTUSR1_DTRD); + term_cond |= sr2 & (MXC_UARTUSR2_RDR | MXC_UARTUSR2_DCDDELT); + term_cond |= !(sr2 & MXC_UARTUSR2_TXFE); + } while (term_cond > 0); + + handled = 1; + return IRQ_RETVAL(handled); +} + +/*! + * Interrupt service routine registered to handle the transmit interrupts. This + * routine is registered only in the case where the UART interrupts are not + * muxed. + * + * @param irq the interrupt number + * @param dev_id driver private data + * + * @return The function returns \b IRQ_RETVAL(1) if interrupt was handled, + * returns \b IRQ_RETVAL(0) if the interrupt was not handled. + * \b IRQ_RETVAL is defined in include/linux/interrupt.h. + */ +static irqreturn_t mxcuart_tx_int(int irq, void *dev_id) +{ + uart_mxc_port *umxc = dev_id; + int handled = 0; + volatile unsigned int sr2, cr; + + /* Echo cancellation for IRDA Transmit chars */ + if (umxc->ir_mode == IRDA && echo_cancel) { + /* Disable the receiver */ + cr = readl(umxc->port.membase + MXC_UARTUCR2); + cr &= ~MXC_UARTUCR2_RXEN; + writel(cr, umxc->port.membase + MXC_UARTUCR2); + /* Enable Transmit complete to reenable receiver */ + cr = readl(umxc->port.membase + MXC_UARTUCR4); + cr |= MXC_UARTUCR4_TCEN; + writel(cr, umxc->port.membase + MXC_UARTUCR4); + } + + mxcuart_tx_chars(umxc); + + /* Is the transmit complete to reenable the receiver? */ + if (umxc->ir_mode == IRDA && echo_cancel) { + sr2 = readl(umxc->port.membase + MXC_UARTUSR2); + if (sr2 & MXC_UARTUSR2_TXDC) { + cr = readl(umxc->port.membase + MXC_UARTUCR2); + cr |= MXC_UARTUCR2_RXEN; + writel(cr, umxc->port.membase + MXC_UARTUCR2); + /* Disable the Transmit complete interrupt bit */ + cr = readl(umxc->port.membase + MXC_UARTUCR4); + cr &= ~MXC_UARTUCR4_TCEN; + writel(cr, umxc->port.membase + MXC_UARTUCR4); + } + } + + handled = 1; + + return IRQ_RETVAL(handled); +} + +/*! + * Interrupt service routine registered to handle the receive interrupts. This + * routine is registered only in the case where the UART interrupts are not + * muxed. + * + * @param irq the interrupt number + * @param dev_id driver private data + * + * @return The function returns \b IRQ_RETVAL(1) if interrupt was handled, + * returns \b IRQ_RETVAL(0) if the interrupt was not handled. + * \b IRQ_RETVAL is defined in include/linux/interrupt.h. + */ +static irqreturn_t mxcuart_rx_int(int irq, void *dev_id) +{ + uart_mxc_port *umxc = dev_id; + int handled = 0; + + /* Clear the aging timer bit */ + writel(MXC_UARTUSR1_AGTIM, umxc->port.membase + MXC_UARTUSR1); + mxcuart_rx_chars(umxc); + handled = 1; + + return IRQ_RETVAL(handled); +} + +/*! + * Interrupt service routine registered to handle the master interrupts. This + * routine is registered only in the case where the UART interrupts are not + * muxed. + * + * @param irq the interrupt number + * @param dev_id driver private data + * + * @return The function returns \b IRQ_RETVAL(1) if interrupt was handled, + * returns \b IRQ_RETVAL(0) if the interrupt was not handled. + * \b IRQ_RETVAL is defined in include/linux/interrupt.h. + */ +static irqreturn_t mxcuart_mint_int(int irq, void *dev_id) +{ + uart_mxc_port *umxc = dev_id; + int handled = 0; + volatile unsigned int sr1, sr2; + + sr1 = readl(umxc->port.membase + MXC_UARTUSR1); + sr2 = readl(umxc->port.membase + MXC_UARTUSR2); + /* Clear the modem status interrupt bits */ + writel(MXC_UARTUSR1_RTSD | MXC_UARTUSR1_DTRD, + umxc->port.membase + MXC_UARTUSR1); + writel(MXC_UARTUSR2_DCDDELT | MXC_UARTUSR2_RIDELT, + umxc->port.membase + MXC_UARTUSR2); + mxcuart_modem_status(umxc, sr1, sr2); + handled = 1; + + return IRQ_RETVAL(handled); +} + +/*! + * This function is called by the core driver to test whether the transmitter + * fifo and shift register for the UART port are empty. + * + * @param port the port structure for the UART passed in by the core driver + * + * @return The function returns TIOCSER_TEMT if it is empty, else returns 0. + */ +static unsigned int mxcuart_tx_empty(struct uart_port *port) +{ + volatile unsigned int sr2; + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + sr2 = readl(port->membase + MXC_UARTUSR2); + spin_unlock_irqrestore(&port->lock, flags); + + return sr2 & MXC_UARTUSR2_TXDC ? TIOCSER_TEMT : 0; +} + +/*! + * This function is called by the core driver to get the current status of the + * modem input signals. The state of the output signals is not collected. + * + * @param port the port structure for the UART passed in by the core driver + * + * @return The function returns an integer that contains the ORed value of the + * status of all the modem input signals or error. + */ +static unsigned int mxcuart_get_mctrl(struct uart_port *port) +{ + uart_mxc_port *umxc = (uart_mxc_port *) port; + unsigned int result = 0; + volatile unsigned int sr1, sr2; + + sr1 = readl(umxc->port.membase + MXC_UARTUSR1); + sr2 = readl(umxc->port.membase + MXC_UARTUSR2); + + if (sr1 & MXC_UARTUSR1_RTSS) { + result |= TIOCM_CTS; + } + if (umxc->mode == MODE_DTE) { + if (!(sr2 & MXC_UARTUSR2_DCDIN)) { + result |= TIOCM_CAR; + } + if (!(sr2 & MXC_UARTUSR2_RIIN)) { + result |= TIOCM_RI; + } + } + return result; +} + +/*! + * This function is called by the core driver to set the state of the modem + * control lines. + * + * @param port the port structure for the UART passed in by the core driver + * @param mctrl the state that the modem control lines should be changed to + */ +static void mxcuart_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + uart_mxc_port *umxc = (uart_mxc_port *) port; + volatile unsigned int cr2 = 0, cr3 = 0, uts = 0; + + cr2 = readl(port->membase + MXC_UARTUCR2); + cr3 = readl(port->membase + MXC_UARTUCR3); + uts = readl(port->membase + MXC_UARTUTS); + + if (mctrl & TIOCM_RTS) { + /* + * Return to hardware-driven hardware flow control if the + * option is enabled + */ + if (umxc->hardware_flow == 1) { + cr2 |= MXC_UARTUCR2_CTSC; + } else { + cr2 |= MXC_UARTUCR2_CTS; + cr2 &= ~MXC_UARTUCR2_CTSC; + } + } else { + cr2 &= ~(MXC_UARTUCR2_CTS | MXC_UARTUCR2_CTSC); + } + writel(cr2, port->membase + MXC_UARTUCR2); + + if (mctrl & TIOCM_DTR) { + cr3 |= MXC_UARTUCR3_DSR; + } else { + cr3 &= ~MXC_UARTUCR3_DSR; + } + writel(cr3, port->membase + MXC_UARTUCR3); + + if (mctrl & TIOCM_LOOP) { + if (umxc->ir_mode == IRDA) { + echo_cancel = 0; + } else { + uts |= MXC_UARTUTS_LOOP; + } + } else { + if (umxc->ir_mode == IRDA) { + echo_cancel = 1; + } else { + uts &= ~MXC_UARTUTS_LOOP; + } + } + writel(uts, port->membase + MXC_UARTUTS); +} + +/*! + * This function is called by the core driver to control the transmission of + * the break signal. If break_state is non-zero, the break signal is + * transmitted, the signal is terminated when another call is made with + * break_state set to 0. + * + * @param port the port structure for the UART passed in by the core + * driver + * @param break_state the requested state of the break signal + */ +static void mxcuart_break_ctl(struct uart_port *port, int break_state) +{ + volatile unsigned int cr1; + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + cr1 = readl(port->membase + MXC_UARTUCR1); + if (break_state == -1) { + cr1 |= MXC_UARTUCR1_SNDBRK; + } else { + cr1 &= ~MXC_UARTUCR1_SNDBRK; + } + writel(cr1, port->membase + MXC_UARTUCR1); + spin_unlock_irqrestore(&port->lock, flags); +} + +/*! + * The read DMA callback, this method is called when the DMA buffer has received its + * data. This functions copies the data to the tty buffer and updates the tty buffer + * pointers. It also queues the DMA buffer back to the DMA system. + * + * @param arg driver private data + * @param error any DMA error + * @param cnt amount of data that was transferred + */ +static void mxcuart_dmaread_callback(void *arg, int error, unsigned int cnt) +{ + uart_mxc_port *umxc = arg; + struct tty_struct *tty = umxc->port.state->port.tty; + int buff_id, flip_cnt, num_bufs; + mxc_dma_requestbuf_t readchnl_request; + mxc_uart_rxdmamap *rx_buf_elem = NULL; + unsigned int sr1, sr2; + char flag; + + num_bufs = umxc->dma_rxbuf_size / RXDMA_BUFF_SIZE; + /* Clear the aging timer bit */ + writel(MXC_UARTUSR1_AGTIM, umxc->port.membase + MXC_UARTUSR1); + + buff_id = umxc->dma_rxbuf_id; + flag = TTY_NORMAL; + + umxc->dma_rxbuf_id += 1; + if (umxc->dma_rxbuf_id >= num_bufs) { + umxc->dma_rxbuf_id = 0; + } + + rx_buf_elem = (mxc_uart_rxdmamap *) (umxc->rx_dmamap + buff_id); + + if (error == MXC_DMA_TRANSFER_ERROR) { + + sr1 = __raw_readl(umxc->port.membase + MXC_UARTUSR1); + sr2 = __raw_readl(umxc->port.membase + MXC_UARTUSR2); + + if (sr2 & MXC_UARTUSR2_BRCD) { + umxc->port.icount.brk++; + if (uart_handle_break(&umxc->port)) { + goto drop_data; + } + } else if (sr1 & MXC_UARTUSR1_PARITYERR) { + umxc->port.icount.parity++; + } else if (sr1 & MXC_UARTUSR1_FRAMERR) { + umxc->port.icount.frame++; + } else if (sr2 & MXC_UARTUSR2_ORE) { + umxc->port.icount.overrun++; + + } + + if (umxc->port.read_status_mask & MXC_UARTURXD_BRK) { + if (sr2 & MXC_UARTUSR2_BRCD) + flag = TTY_BREAK; + } else if (umxc->port.read_status_mask & MXC_UARTURXD_PRERR) { + if (sr1 & MXC_UARTUSR1_PARITYERR) + flag = TTY_PARITY; + } else if (umxc->port.read_status_mask & MXC_UARTURXD_FRMERR) { + if (sr1 & MXC_UARTUSR1_FRAMERR) + flag = TTY_FRAME; + } else if (umxc->port.read_status_mask & MXC_UARTURXD_OVRRUN) { + if (sr2 & MXC_UARTUSR2_ORE) + flag = TTY_OVERRUN; + } +/* By default clearing all error bits in status reg */ + __raw_writel((MXC_UARTUSR2_BRCD | MXC_UARTUSR2_ORE), + umxc->port.membase + MXC_UARTUSR2); + __raw_writel((MXC_UARTUSR1_PARITYERR | MXC_UARTUSR1_FRAMERR), + umxc->port.membase + MXC_UARTUSR1); + } + + flip_cnt = tty_buffer_request_room(tty, cnt); + + /* Check for space availability in the TTY Flip buffer */ + if (flip_cnt <= 0) { + goto drop_data; + } + umxc->port.icount.rx += flip_cnt; + + tty_insert_flip_string(tty, rx_buf_elem->rx_buf, flip_cnt); + + if (flag != TTY_NORMAL) { + tty_insert_flip_char(tty, 0, flag); + } + + tty_flip_buffer_push(tty); + umxc->port.state->port.tty->real_raw = 1; + + drop_data: + readchnl_request.src_addr = umxc->port.mapbase; + readchnl_request.dst_addr = rx_buf_elem->rx_handle; + readchnl_request.num_of_bytes = RXDMA_BUFF_SIZE; + mxc_dma_config(dma_list[umxc->port.line].rd_channel, &readchnl_request, + 1, MXC_DMA_MODE_READ); + mxc_dma_enable(dma_list[umxc->port.line].rd_channel); +} + +/*! + * Allocates DMA read and write channels, creates DMA read and write buffers and + * sets the channel specific parameters. + * + * @param d_info the structure that holds all the DMA information for a + * particular MXC UART + * @param umxc the MXC UART port structure, this includes the \b uart_port + * structure and other members that are specific to MXC UARTs + * + * @return The function returns 0 on success and a non-zero value on failure. + */ +static int mxcuart_initdma(dma_info *d_info, uart_mxc_port *umxc) +{ + int ret = 0, rxbufs, i, j; + mxc_dma_requestbuf_t *readchnl_reqelem; + mxc_uart_rxdmamap *rx_buf_elem; + + /* Request for the read and write channels */ + d_info->rd_channel = mxc_dma_request(umxc->dma_rx_id, "MXC UART Read"); + if (d_info->rd_channel < 0) { + printk(KERN_ERR "MXC UART: Cannot allocate DMA read channel\n"); + return -1; + } else { + d_info->wr_channel = + mxc_dma_request(umxc->dma_tx_id, "MXC UART Write"); + if (d_info->wr_channel < 0) { + mxc_dma_free(d_info->rd_channel); + printk(KERN_ERR + "MXC UART: Cannot allocate DMA write channel\n"); + return -1; + } + } + + /* Allocate the DMA Transmit Buffer */ + umxc->tx_buf = kmalloc(TXDMA_BUFF_SIZE, GFP_KERNEL); + if (umxc->tx_buf == NULL) { + ret = -1; + goto err_dma_tx_buff; + } + rxbufs = umxc->dma_rxbuf_size / RXDMA_BUFF_SIZE; + /* Allocate the DMA Virtual Receive Buffer */ + umxc->rx_dmamap = kmalloc(rxbufs * sizeof(mxc_uart_rxdmamap), GFP_KERNEL); + if (umxc->rx_dmamap == NULL) { + ret = -1; + goto err_dma_rx_buff; + } + + /* Allocate the DMA Receive Request structures */ + readchnl_reqelem = kmalloc(rxbufs * sizeof(mxc_dma_requestbuf_t), + GFP_KERNEL); + if (readchnl_reqelem == NULL) { + ret = -1; + goto err_request; + } + + for (i = 0; i < rxbufs; i++) { + rx_buf_elem = (mxc_uart_rxdmamap *) (umxc->rx_dmamap + i); + rx_buf_elem->rx_buf = + dma_alloc_coherent(NULL, RXDMA_BUFF_SIZE, + &rx_buf_elem->rx_handle, GFP_DMA); + if (rx_buf_elem->rx_buf == NULL) { + for (j = 0; j < i; j++) { + rx_buf_elem = + (mxc_uart_rxdmamap *) (umxc->rx_dmamap + j); + dma_free_coherent(NULL, RXDMA_BUFF_SIZE, + rx_buf_elem->rx_buf, + rx_buf_elem->rx_handle); + } + ret = -1; + goto cleanup; + } + } + + umxc->dma_rxbuf_id = 0; + /* Setup the DMA read request structures */ + for (i = 0; i < rxbufs; i++) { + rx_buf_elem = (mxc_uart_rxdmamap *) (umxc->rx_dmamap + i); + (readchnl_reqelem + i)->src_addr = umxc->port.mapbase; + (readchnl_reqelem + i)->dst_addr = rx_buf_elem->rx_handle; + (readchnl_reqelem + i)->num_of_bytes = RXDMA_BUFF_SIZE; + } + mxc_dma_config(d_info->rd_channel, readchnl_reqelem, rxbufs, + MXC_DMA_MODE_READ); + mxc_dma_callback_set(d_info->rd_channel, mxcuart_dmaread_callback, + umxc); + mxc_dma_callback_set(d_info->wr_channel, mxcuart_dma_writecallback, + umxc); + + /* Start the read channel */ + mxc_dma_enable(d_info->rd_channel); + kfree(readchnl_reqelem); + tasklet_init(&d_info->dma_tx_tasklet, dma_tx_do_tasklet, + (unsigned long)umxc); + d_info->dma_txchnl_inuse = 0; + return ret; + cleanup: + kfree(readchnl_reqelem); + err_request: + kfree(umxc->rx_dmamap); + err_dma_rx_buff: + kfree(umxc->tx_buf); + err_dma_tx_buff: + mxc_dma_free(d_info->rd_channel); + mxc_dma_free(d_info->wr_channel); + + return ret; +} + +/*! + * Stops DMA and frees the DMA resources + * + * @param d_info the structure that holds all the DMA information for a + * particular MXC UART + * @param umxc the MXC UART port structure, this includes the \b uart_port + * structure and other members that are specific to MXC UARTs + */ +static void mxcuart_freedma(dma_info *d_info, uart_mxc_port *umxc) +{ + int i, rxbufs; + mxc_uart_rxdmamap *rx_buf_elem; + + rxbufs = umxc->dma_rxbuf_size / RXDMA_BUFF_SIZE; + + for (i = 0; i < rxbufs; i++) { + rx_buf_elem = (mxc_uart_rxdmamap *) (umxc->rx_dmamap + i); + dma_free_coherent(NULL, RXDMA_BUFF_SIZE, + rx_buf_elem->rx_buf, rx_buf_elem->rx_handle); + } + kfree(umxc->rx_dmamap); + kfree(umxc->tx_buf); + mxc_dma_free(d_info->rd_channel); + mxc_dma_free(d_info->wr_channel); +} + +/*! + * This function is called to free the interrupts. + * + * @param umxc the MXC UART port structure, this includes the \b uart_port + * structure and other members that are specific to MXC UARTs + */ +static void mxcuart_free_interrupts(uart_mxc_port *umxc) +{ + free_irq(umxc->port.irq, umxc); + if (umxc->ints_muxed == 0) { + free_irq(umxc->irqs[0], umxc); + free_irq(umxc->irqs[1], umxc); + } +} + +/*! + * Calculate and set the UART port clock value + * + * @param umxc the MXC UART port structure, this includes the \b uart_port + * structure and other members that are specific to MXC UARTs + * @param per_clk peripheral clock coming into the MXC UART module + * @param req_baud current baudrate requested + * @param div returns the reference frequency divider value + */ +static void mxcuart_set_ref_freq(uart_mxc_port *umxc, unsigned long per_clk, + unsigned int req_baud, int *div) +{ + unsigned int d = 1; + + /* + * Choose the smallest possible prescaler to maximize + * the chance of using integer scaling. Ensure that + * the calculation won't overflow. Limit the denom + * to 15 bits since a 16-bit denom doesn't work. + */ + if (req_baud < (1 << (31 - (4 + 15)))) + d = per_clk / (req_baud << (4 + 15)) + 1; + + umxc->port.uartclk = per_clk / d; + + /* + * Set the ONEMS register that is used by IR special case bit and + * the Escape character detect logic + */ + writel(umxc->port.uartclk / 1000, umxc->port.membase + MXC_UARTONEMS); + *div = d; +} + +/*! + * This function is called by the core driver to initialize the low-level + * driver. The function grabs the interrupt resources and registers its + * interrupt service routines. It then initializes the IOMUX registers to + * configure the pins for UART signals and finally initializes the various + * UART registers and enables the port for reception. + * + * @param port the port structure for the UART passed in by the core driver + * + * @return The function returns 0 on success and a non-zero value on failure. + */ +static int mxcuart_startup(struct uart_port *port) +{ + uart_mxc_port *umxc = (uart_mxc_port *) port; + int retval; + volatile unsigned int cr, cr1 = 0, cr2 = 0, ufcr = 0; + + /* + * Some UARTs need separate registrations for the interrupts as + * they do not take the muxed interrupt output to the ARM core + */ + if (umxc->ints_muxed == 1) { + retval = request_irq(umxc->port.irq, mxcuart_int, 0, + "mxcintuart", umxc); + if (retval != 0) { + return retval; + } + } else { + retval = request_irq(umxc->port.irq, mxcuart_tx_int, + 0, "mxcintuart", umxc); + if (retval != 0) { + return retval; + } else { + retval = request_irq(umxc->irqs[0], mxcuart_rx_int, + 0, "mxcintuart", umxc); + if (retval != 0) { + free_irq(umxc->port.irq, umxc); + return retval; + } else { + retval = + request_irq(umxc->irqs[1], mxcuart_mint_int, + 0, "mxcintuart", umxc); + if (retval != 0) { + free_irq(umxc->port.irq, umxc); + free_irq(umxc->irqs[0], umxc); + return retval; + } + } + } + } + + /* Initialize the DMA if we need SDMA data transfer */ + if (umxc->dma_enabled == 1) { + retval = mxcuart_initdma(dma_list + umxc->port.line, umxc); + if (retval != 0) { + printk + (KERN_ERR + "MXC UART: Failed to initialize DMA for UART %d\n", + umxc->port.line); + mxcuart_free_interrupts(umxc); + return retval; + } + /* Configure the GPR register to receive SDMA events */ + config_uartdma_event(umxc->port.line); + } + + /* + * Clear Status Registers 1 and 2 + */ + writel(0xFFFF, umxc->port.membase + MXC_UARTUSR1); + writel(0xFFFF, umxc->port.membase + MXC_UARTUSR2); + + /* Configure the IOMUX for the UART */ + gpio_uart_active(umxc->port.line, umxc->ir_mode); + + /* + * Set the transceiver invert bits if required + */ + if (umxc->ir_mode == IRDA) { + echo_cancel = 1; + writel(umxc->ir_rx_inv | MXC_UARTUCR4_IRSC, umxc->port.membase + + MXC_UARTUCR4); + writel(umxc->rxd_mux | umxc->ir_tx_inv, + umxc->port.membase + MXC_UARTUCR3); + } else { + writel(umxc->rxd_mux, umxc->port.membase + MXC_UARTUCR3); + } + + /* + * Initialize UCR1,2 and UFCR registers + */ + if (umxc->dma_enabled == 1) { + cr2 = (MXC_UARTUCR2_TXEN | MXC_UARTUCR2_RXEN); + } else { + cr2 = + (MXC_UARTUCR2_ATEN | MXC_UARTUCR2_TXEN | MXC_UARTUCR2_RXEN); + } + + writel(cr2, umxc->port.membase + MXC_UARTUCR2); + /* Wait till we are out of software reset */ + do { + cr = readl(umxc->port.membase + MXC_UARTUCR2); + } while (!(cr & MXC_UARTUCR2_SRST)); + + if (umxc->mode == MODE_DTE) { + ufcr |= ((umxc->tx_threshold << MXC_UARTUFCR_TXTL_OFFSET) | + MXC_UARTUFCR_DCEDTE | MXC_UARTUFCR_RFDIV | umxc-> + rx_threshold); + } else { + ufcr |= ((umxc->tx_threshold << MXC_UARTUFCR_TXTL_OFFSET) | + MXC_UARTUFCR_RFDIV | umxc->rx_threshold); + } + writel(ufcr, umxc->port.membase + MXC_UARTUFCR); + + /* + * Finally enable the UART and the Receive interrupts + */ + if (umxc->ir_mode == IRDA) { + cr1 |= MXC_UARTUCR1_IREN; + } + if (umxc->dma_enabled == 1) { + cr1 |= (MXC_UARTUCR1_RXDMAEN | MXC_UARTUCR1_ATDMAEN | + MXC_UARTUCR1_UARTEN); + } else { + cr1 |= (MXC_UARTUCR1_RRDYEN | MXC_UARTUCR1_UARTEN); + } + writel(cr1, umxc->port.membase + MXC_UARTUCR1); + + return 0; +} + +/*! + * This function is called by the core driver for the low-level driver to free + * its resources. The function frees all its interrupts and disables the UART. + * + * @param port the port structure for the UART passed in by the core driver + */ +static void mxcuart_shutdown(struct uart_port *port) +{ + uart_mxc_port *umxc = (uart_mxc_port *) port; + + /* Disable the IOMUX for the UART */ + gpio_uart_inactive(umxc->port.line, umxc->ir_mode); + mxcuart_free_interrupts(umxc); + /* Disable all interrupts, port and break condition */ + writel(0, umxc->port.membase + MXC_UARTUCR1); + writel(0, umxc->port.membase + MXC_UARTUCR3); + if (umxc->dma_enabled == 1) { + mxcuart_freedma(dma_list + umxc->port.line, umxc); + } +} + +/*! + * This function is called by the core driver to change the UART parameters, + * including baudrate, word length, parity, stop bits. The function also updates + * the port structures mask registers to indicate the types of events the user is + * interested in receiving. + * + * @param port the port structure for the UART passed in by the core driver + * @param termios the desired termios settings + * @param old old termios + */ +static void mxcuart_set_termios(struct uart_port *port, + struct ktermios *termios, struct ktermios *old) +{ + uart_mxc_port *umxc = (uart_mxc_port *) port; + volatile unsigned int cr4 = 0, cr2 = 0, ufcr; + u_int num, denom, baud; + u_int cr2_mask; /* Used to add the changes to CR2 */ + unsigned long flags, per_clk; + int div; + + cr2_mask = ~(MXC_UARTUCR2_IRTS | MXC_UARTUCR2_CTSC | MXC_UARTUCR2_PREN | + MXC_UARTUCR2_PROE | MXC_UARTUCR2_STPB | MXC_UARTUCR2_WS); + + per_clk = clk_get_rate(umxc->clk); + + /* + * Ask the core to get the baudrate, if requested baudrate is not + * between max and min, then either use the baudrate in old termios + * setting. If it's still invalid, we try 9600 baud. + */ + baud = uart_get_baud_rate(&umxc->port, termios, old, 0, per_clk / 16); + /* Set the Reference frequency divider */ + mxcuart_set_ref_freq(umxc, per_clk, baud, &div); + + /* Byte size, default is 8-bit mode */ + switch (termios->c_cflag & CSIZE) { + case CS7: + cr2 = 0; + break; + default: + cr2 = MXC_UARTUCR2_WS; + break; + } + /* Check to see if we need 2 Stop bits */ + if (termios->c_cflag & CSTOPB) { + cr2 |= MXC_UARTUCR2_STPB; + } + + /* Check to see if we need Parity checking */ + if (termios->c_cflag & PARENB) { + cr2 |= MXC_UARTUCR2_PREN; + if (termios->c_cflag & PARODD) { + cr2 |= MXC_UARTUCR2_PROE; + } + } + spin_lock_irqsave(&umxc->port.lock, flags); + + ufcr = readl(umxc->port.membase + MXC_UARTUFCR); + ufcr = (ufcr & (~MXC_UARTUFCR_RFDIV_MASK)) | + ((6 - div) << MXC_UARTUFCR_RFDIV_OFFSET); + writel(ufcr, umxc->port.membase + MXC_UARTUFCR); + + /* + * Update the per-port timeout + */ + uart_update_timeout(&umxc->port, termios->c_cflag, baud); + + umxc->port.read_status_mask = MXC_UARTURXD_OVRRUN; + /* + * Enable appropriate events to be passed to the TTY layer + */ + if (termios->c_iflag & INPCK) { + umxc->port.read_status_mask |= MXC_UARTURXD_FRMERR | + MXC_UARTURXD_PRERR; + } + if (termios->c_iflag & (BRKINT | PARMRK)) { + umxc->port.read_status_mask |= MXC_UARTURXD_BRK; + } + + /* + * Characters to ignore + */ + umxc->port.ignore_status_mask = 0; + if (termios->c_iflag & IGNPAR) { + umxc->port.ignore_status_mask |= MXC_UARTURXD_FRMERR | + MXC_UARTURXD_PRERR; + } + if (termios->c_iflag & IGNBRK) { + umxc->port.ignore_status_mask |= MXC_UARTURXD_BRK; + /* + * If we are ignoring parity and break indicators, + * ignore overruns too (for real raw support) + */ + if (termios->c_iflag & IGNPAR) { + umxc->port.ignore_status_mask |= MXC_UARTURXD_OVRRUN; + } + } + + /* + * Ignore all characters if CREAD is not set, still receive characters + * from the port, but throw them away. + */ + if ((termios->c_cflag & CREAD) == 0) { + umxc->port.ignore_status_mask |= UART_CREAD_BIT; + } + + /* Hardware flow control should controled by userspace */ + umxc->hardware_flow = (termios->c_cflag & CRTSCTS) ? 1 : 0; + + cr4 = readl(umxc->port.membase + MXC_UARTUCR4); + if (UART_ENABLE_MS(port, termios->c_cflag)) { + mxcuart_enable_ms(port); + if (umxc->hardware_flow == 1) { + cr4 = (cr4 & (~MXC_UARTUCR4_CTSTL_MASK)) | + (umxc->cts_threshold << MXC_UARTUCR4_CTSTL_OFFSET); + cr2 |= MXC_UARTUCR2_CTSC; + umxc->port.state->port.tty->hw_stopped = 0; + } else { + cr2 |= MXC_UARTUCR2_IRTS; + } + } else { + cr2 |= MXC_UARTUCR2_IRTS; + } + + /* Add Parity, character length and stop bits information */ + cr2 |= (readl(umxc->port.membase + MXC_UARTUCR2) & cr2_mask); + writel(cr2, umxc->port.membase + MXC_UARTUCR2); + /* + if (umxc->ir_mode == IRDA) { + ret = mxcuart_setir_special(baud); + if (ret == 0) { + cr4 &= ~MXC_UARTUCR4_IRSC; + } else { + cr4 |= MXC_UARTUCR4_IRSC; + } + } */ + writel(cr4, umxc->port.membase + MXC_UARTUCR4); + + /* + * Set baud rate + */ + + /* Use integer scaling, if possible. Limit the denom to 15 bits. */ + num = 0; + denom = (umxc->port.uartclk + 8 * baud) / (16 * baud) - 1; + + /* Use fractional scaling if needed to limit the max error to 0.5% */ + if (denom < 100) { + u64 n64 = (u64) 16 * 0x8000 * baud + (umxc->port.uartclk / 2); + do_div(n64, umxc->port.uartclk); + num = (u_int) n64 - 1; + denom = 0x7fff; + } + writel(num, umxc->port.membase + MXC_UARTUBIR); + writel(denom, umxc->port.membase + MXC_UARTUBMR); + + spin_unlock_irqrestore(&umxc->port.lock, flags); +} + +/*! + * This function is called by the core driver to know the UART type. + * + * @param port the port structure for the UART passed in by the core driver + * + * @return The function returns a pointer to a string describing the UART port. + */ +static const char *mxcuart_type(struct uart_port *port) +{ + return port->type == PORT_IMX ? "Freescale i.MX" : NULL; +} + +/*! + * This function is called by the core driver to release the memory resources + * currently in use by the UART port. + * + * @param port the port structure for the UART passed in by the core driver + */ +static void mxcuart_release_port(struct uart_port *port) +{ + release_mem_region(port->mapbase, SZ_4K); +} + +/*! + * This function is called by the core driver to request memory resources for + * the UART port. + * + * @param port the port structure for the UART passed in by the core driver + * + * @return The function returns \b -EBUSY on failure, else it returns 0. + */ +static int mxcuart_request_port(struct uart_port *port) +{ + struct platform_device *pdev = to_platform_device(port->dev); + struct resource *mmres; + void *ret; + + mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!mmres) + return -ENODEV; + + ret = request_mem_region(mmres->start, mmres->end - mmres->start + 1, + "serial_mxc"); + + return ret ? 0 : -EBUSY; +} + +/*! + * This function is called by the core driver to perform any autoconfiguration + * steps required for the UART port. This function sets the port->type field. + * + * @param port the port structure for the UART passed in by the core driver + * @param flags bit mask of the required configuration + */ +static void mxcuart_config_port(struct uart_port *port, int flags) +{ + if ((flags & UART_CONFIG_TYPE) && (mxcuart_request_port(port) == 0)) { + port->type = PORT_IMX; + } +} + +/*! + * This function is called by the core driver to verify that the new serial + * port information contained within \a ser is suitable for this UART port type. + * The function checks to see if the UART port type specified by the user + * application while setting the UART port information matches what is stored + * in the define \b PORT_MXC found in the header file include/linux/serial_core.h + * + * @param port the port structure for the UART passed in by the core driver + * @param ser the new serial port information + * + * @return The function returns 0 on success or \b -EINVAL if the port type + * specified is not equal to \b PORT_MXC. + */ +static int mxcuart_verify_port(struct uart_port *port, + struct serial_struct *ser) +{ + int ret = 0; + if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX) { + ret = -EINVAL; + } + return ret; +} + +/*! + * This function is used to send a high priority XON/XOFF character + * + * @param port the port structure for the UART passed in by the core driver + * @param ch the character to send + */ +static void mxcuart_send_xchar(struct uart_port *port, char ch) +{ + unsigned long flags; + + port->x_char = ch; + if (port->state->port.tty->hw_stopped) { + return; + } + + if (ch) { + spin_lock_irqsave(&port->lock, flags); + port->ops->start_tx(port); + spin_unlock_irqrestore(&port->lock, flags); + } +} + +/*! + * This function is used enable/disable the MXC UART clocks + * + * @param port the port structure for the UART passed in by the core driver + * @param state New PM state + * @param oldstate Current PM state + */ +static void +mxcuart_pm(struct uart_port *port, unsigned int state, unsigned int oldstate) +{ + uart_mxc_port *umxc = (uart_mxc_port *) port; + + if (state) + clk_disable(umxc->clk); + else + clk_enable(umxc->clk); +} + +/*! + * This structure contains the pointers to the control functions that are + * invoked by the core serial driver to access the UART hardware. The + * structure is passed to serial_core.c file during registration. + */ +static struct uart_ops mxc_ops = { + .tx_empty = mxcuart_tx_empty, + .set_mctrl = mxcuart_set_mctrl, + .get_mctrl = mxcuart_get_mctrl, + .stop_tx = mxcuart_stop_tx, + .start_tx = mxcuart_start_tx, + .stop_rx = mxcuart_stop_rx, + .enable_ms = mxcuart_enable_ms, + .break_ctl = mxcuart_break_ctl, + .startup = mxcuart_startup, + .shutdown = mxcuart_shutdown, + .set_termios = mxcuart_set_termios, + .type = mxcuart_type, + .pm = mxcuart_pm, + .release_port = mxcuart_release_port, + .request_port = mxcuart_request_port, + .config_port = mxcuart_config_port, + .verify_port = mxcuart_verify_port, + .send_xchar = mxcuart_send_xchar, +}; + +#ifdef CONFIG_SERIAL_MXC_CONSOLE + +/* + * Write out a character once the UART is ready + */ +static inline void mxcuart_console_write_char(struct uart_port *port, char ch) +{ + volatile unsigned int status; + + do { + status = readl(port->membase + MXC_UARTUSR1); + } while ((status & MXC_UARTUSR1_TRDY) == 0); + writel(ch, port->membase + MXC_UARTUTXD); +} + +/*! + * This function is called to write the console messages through the UART port. + * + * @param co the console structure + * @param s the log message to be written to the UART + * @param count length of the message + */ +static void mxcuart_console_write(struct console *co, const char *s, + u_int count) +{ + struct uart_port *port = &mxc_ports[co->index]->port; + volatile unsigned int status, oldcr1, oldcr2, oldcr3, cr2, cr3; + int i; + + /* + * First save the control registers and then disable the interrupts + */ + oldcr1 = readl(port->membase + MXC_UARTUCR1); + oldcr2 = readl(port->membase + MXC_UARTUCR2); + oldcr3 = readl(port->membase + MXC_UARTUCR3); + cr2 = + oldcr2 & ~(MXC_UARTUCR2_ATEN | MXC_UARTUCR2_RTSEN | + MXC_UARTUCR2_ESCI); + cr3 = + oldcr3 & ~(MXC_UARTUCR3_DCD | MXC_UARTUCR3_RI | + MXC_UARTUCR3_DTRDEN); + writel(MXC_UARTUCR1_UARTEN, port->membase + MXC_UARTUCR1); + writel(cr2, port->membase + MXC_UARTUCR2); + writel(cr3, port->membase + MXC_UARTUCR3); + /* + * Do each character + */ + for (i = 0; i < count; i++) { + mxcuart_console_write_char(port, s[i]); + if (s[i] == '\n') { + mxcuart_console_write_char(port, '\r'); + } + } + /* + * Finally, wait for the transmitter to become empty + */ + do { + status = readl(port->membase + MXC_UARTUSR2); + } while (!(status & MXC_UARTUSR2_TXDC)); + + /* + * Restore the control registers + */ + writel(oldcr1, port->membase + MXC_UARTUCR1); + writel(oldcr2, port->membase + MXC_UARTUCR2); + writel(oldcr3, port->membase + MXC_UARTUCR3); +} + +/*! + * Initializes the UART port to be used to print console message with the + * options specified. If no options are specified, then the function + * initializes the UART with the default options of baudrate=115200, 8 bit + * word size, no parity, no flow control. + * + * @param co The console structure + * @param options Any console options passed in from the command line + * + * @return The function returns 0 on success or error. + */ +static int __init mxcuart_console_setup(struct console *co, char *options) +{ + uart_mxc_port *umxc; + int baud = 115200; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + volatile unsigned int cr = 0; + + /* + * Check whether an invalid uart number had been specified, and if + * so, search for the first available port that does have console + * support + */ + if (co->index >= MXC_UART_NR) { + co->index = 0; + } + umxc = mxc_ports[co->index]; + + if (umxc == NULL) { + return -ENODEV; + } + + clk_enable(umxc->clk); + + /* initialize port.lock else oops */ + spin_lock_init(&umxc->port.lock); + + /* + * Initialize the UART registers + */ + writel(MXC_UARTUCR1_UARTEN, umxc->port.membase + MXC_UARTUCR1); + /* Enable the transmitter and do a software reset */ + writel(MXC_UARTUCR2_TXEN, umxc->port.membase + MXC_UARTUCR2); + /* Wait till we are out of software reset */ + do { + cr = readl(umxc->port.membase + MXC_UARTUCR2); + } while (!(cr & MXC_UARTUCR2_SRST)); + + writel(0x0, umxc->port.membase + MXC_UARTUCR3); + writel(0x0, umxc->port.membase + MXC_UARTUCR4); + /* Set TXTL to 2, RXTL to 1 and RFDIV to 2 */ + cr = 0x0800 | MXC_UARTUFCR_RFDIV | 0x1; + if (umxc->mode == MODE_DTE) { + cr |= MXC_UARTUFCR_DCEDTE; + } + writel(cr, umxc->port.membase + MXC_UARTUFCR); + writel(0xFFFF, umxc->port.membase + MXC_UARTUSR1); + writel(0xFFFF, umxc->port.membase + MXC_UARTUSR2); + + if (options != NULL) { + uart_parse_options(options, &baud, &parity, &bits, &flow); + } + gpio_uart_active(umxc->port.line, umxc->ir_mode); + return uart_set_options(&umxc->port, co, baud, parity, bits, flow); +} + +static struct uart_driver mxc_reg; + +/*! + * This structure contains the pointers to the UART console functions. It is + * passed as an argument when registering the console. + */ +static struct console mxc_console = { + .name = "ttymxc", + .write = mxcuart_console_write, + .device = uart_console_device, + .setup = mxcuart_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &mxc_reg, +}; + +/*! + * This function registers the console callback functions with the kernel. + */ +static int __init mxcuart_console_init(void) +{ + register_console(&mxc_console); + return 0; +} + +console_initcall(mxcuart_console_init); + +static int __init find_port(struct uart_port *p) +{ + int line; + struct uart_port *port; + for (line = 0; line < MXC_UART_NR; line++) { + if (!mxc_ports[line]) + continue; + port = &mxc_ports[line]->port; + if (uart_match_port(p, port)) + return line; + } + return -ENODEV; +} + +int __init mxc_uart_start_console(struct uart_port *port, char *options) +{ + int line; + line = find_port(port); + if (line < 0) + return -ENODEV; + + add_preferred_console("ttymxc", line, options); + printk("Switching Console to ttymxc%d at %s 0x%lx (options '%s')\n", + line, port->iotype == UPIO_MEM ? "MMIO" : "I/O port", + port->iotype == + UPIO_MEM ? (unsigned long)port->mapbase : (unsigned long)port-> + iobase, options); + + if (!(mxc_console.flags & CON_ENABLED)) { + mxc_console.flags &= ~CON_PRINTBUFFER; + register_console(&mxc_console); + } + return 0; +} + +#define MXC_CONSOLE (&mxc_console) +#else +#define MXC_CONSOLE NULL +#endif /* CONFIG_SERIAL_MXC_CONSOLE */ + +/*! + * This structure contains the information such as the name of the UART driver + * that appears in the /dev folder, major and minor numbers etc. This structure + * is passed to the serial_core.c file. + */ +static struct uart_driver mxc_reg = { + .owner = THIS_MODULE, + .driver_name = "ttymxc", + .dev_name = "ttymxc", + .major = SERIAL_MXC_MAJOR, + .minor = SERIAL_MXC_MINOR, + .nr = MXC_UART_NR, + .cons = MXC_CONSOLE, +}; + +/*! + * This function is called to put the UART in a low power state. Refer to the + * document driver-model/driver.txt in the kernel source tree for more + * information. + * + * @param pdev the device structure used to give information on which UART + * to suspend + * @param state the power state the device is entering + * + * @return The function returns 0 on success and -1 on failure + */ +static int mxcuart_suspend(struct platform_device *pdev, pm_message_t state) +{ + uart_mxc_port *umxc = platform_get_drvdata(pdev); + + if (umxc == NULL) + return 0; /* skip disabled ports */ + + if (umxc && umxc->port.flags & ASYNC_INITIALIZED) + uart_suspend_port(&mxc_reg, &umxc->port); + + if (umxc && umxc->port.flags & ASYNC_SUSPENDED) + umxc->port.state->port.tty->hw_stopped = 1; + + return 0; +} + +/*! + * This function is called to bring the UART back from a low power state. Refer + * to the document driver-model/driver.txt in the kernel source tree for more + * information. + * + * @param pdev the device structure used to give information on which UART + * to resume + * + * @return The function returns 0 on success and -1 on failure + */ +static int mxcuart_resume(struct platform_device *pdev) +{ + uart_mxc_port *umxc = platform_get_drvdata(pdev); + + if (umxc == NULL) + return 0; /* skip disabled ports */ + + if (umxc && umxc->port.flags & ASYNC_SUSPENDED) { + umxc->port.state->port.tty->hw_stopped = 0; + uart_resume_port(&mxc_reg, &umxc->port); + } + + return 0; +} + +/*! + * This function is called during the driver binding process. Based on the UART + * that is being probed this function adds the appropriate UART port structure + * in the core driver. + * + * @param pdev the device structure used to store device specific + * information that is used by the suspend, resume and remove + * functions + * + * @return The function returns 0 if successful; -1 otherwise. + */ +static int mxcuart_probe(struct platform_device *pdev) +{ + int id = pdev->id; + struct resource *res; + void __iomem *base; + + mxc_ports[id] = pdev->dev.platform_data; + mxc_ports[id]->port.ops = &mxc_ops; + + /* Do not use UARTs that are disabled during integration */ + if (mxc_ports[id]->enabled == 1) { + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENODEV; + + base = ioremap(res->start, res->end - res->start + 1); + if (!base) + return -ENOMEM; + + mxc_ports[id]->port.membase = base; + mxc_ports[id]->port.mapbase = res->start; + mxc_ports[id]->port.dev = &pdev->dev; + mxc_ports[id]->port.irq = platform_get_irq(pdev, 0); + mxc_ports[id]->irqs[0] = platform_get_irq(pdev, 1); + mxc_ports[id]->irqs[1] = platform_get_irq(pdev, 2); + spin_lock_init(&mxc_ports[id]->port.lock); + /* Enable the low latency flag for DMA UART ports */ + if (mxc_ports[id]->dma_enabled == 1) { + mxc_ports[id]->port.flags |= ASYNC_LOW_LATENCY; + } + + mxc_ports[id]->clk = clk_get(&pdev->dev, NULL); + if (mxc_ports[id]->clk == NULL) + return -1; + + uart_add_one_port(&mxc_reg, &mxc_ports[id]->port); + platform_set_drvdata(pdev, mxc_ports[id]); + } + return 0; +} + +/*! + * Dissociates the driver from the UART device. Removes the appropriate UART + * port structure from the core driver. + * + * @param pdev the device structure used to give information on which UART + * to remove + * + * @return The function always returns 0. + */ +static int mxcuart_remove(struct platform_device *pdev) +{ + uart_mxc_port *umxc = platform_get_drvdata(pdev); + + platform_set_drvdata(pdev, NULL); + + if (umxc) { + uart_remove_one_port(&mxc_reg, &umxc->port); + iounmap(umxc->port.membase); + } + return 0; +} + +/*! + * This structure contains pointers to the power management callback functions. + */ +static struct platform_driver mxcuart_driver = { + .driver = { + .name = "mxcintuart", + }, + .probe = mxcuart_probe, + .remove = mxcuart_remove, + .suspend = mxcuart_suspend, + .resume = mxcuart_resume, +}; + +/*! + * This function is used to initialize the UART driver module. The function + * registers the power management callback functions with the kernel and also + * registers the UART callback functions with the core serial driver. + * + * @return The function returns 0 on success and a non-zero value on failure. + */ +static int __init mxcuart_init(void) +{ + int ret = 0; + + printk(KERN_INFO "Serial: MXC Internal UART driver\n"); + ret = uart_register_driver(&mxc_reg); + if (ret == 0) { + /* Register the device driver structure. */ + ret = platform_driver_register(&mxcuart_driver); + if (ret != 0) { + uart_unregister_driver(&mxc_reg); + } + } + return ret; +} + +/*! + * This function is used to cleanup all resources before the driver exits. + */ +static void __exit mxcuart_exit(void) +{ + platform_driver_unregister(&mxcuart_driver); + uart_unregister_driver(&mxc_reg); +} + +module_init(mxcuart_init); +module_exit(mxcuart_exit); + +MODULE_AUTHOR("Freescale Semiconductor, Inc."); +MODULE_DESCRIPTION("MXC serial port driver"); +MODULE_LICENSE("GPL"); |