diff options
Diffstat (limited to 'drivers/serial/max3107.c')
| -rw-r--r-- | drivers/serial/max3107.c | 1197 |
1 files changed, 1197 insertions, 0 deletions
diff --git a/drivers/serial/max3107.c b/drivers/serial/max3107.c new file mode 100644 index 00000000000..67283c1a57f --- /dev/null +++ b/drivers/serial/max3107.c @@ -0,0 +1,1197 @@ +/* + * max3107.c - spi uart protocol driver for Maxim 3107 + * Based on max3100.c + * by Christian Pellegrin <chripell@evolware.org> + * and max3110.c + * by Feng Tang <feng.tang@intel.com> + * + * Copyright (C) Aavamobile 2009 + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + */ + +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/serial_core.h> +#include <linux/serial.h> +#include <linux/gpio.h> +#include <linux/spi/spi.h> +#include <linux/freezer.h> +#include "max3107.h" + +static const struct baud_table brg26_ext[] = { + { 300, MAX3107_BRG26_B300 }, + { 600, MAX3107_BRG26_B600 }, + { 1200, MAX3107_BRG26_B1200 }, + { 2400, MAX3107_BRG26_B2400 }, + { 4800, MAX3107_BRG26_B4800 }, + { 9600, MAX3107_BRG26_B9600 }, + { 19200, MAX3107_BRG26_B19200 }, + { 57600, MAX3107_BRG26_B57600 }, + { 115200, MAX3107_BRG26_B115200 }, + { 230400, MAX3107_BRG26_B230400 }, + { 460800, MAX3107_BRG26_B460800 }, + { 921600, MAX3107_BRG26_B921600 }, + { 0, 0 } +}; + +static const struct baud_table brg13_int[] = { + { 300, MAX3107_BRG13_IB300 }, + { 600, MAX3107_BRG13_IB600 }, + { 1200, MAX3107_BRG13_IB1200 }, + { 2400, MAX3107_BRG13_IB2400 }, + { 4800, MAX3107_BRG13_IB4800 }, + { 9600, MAX3107_BRG13_IB9600 }, + { 19200, MAX3107_BRG13_IB19200 }, + { 57600, MAX3107_BRG13_IB57600 }, + { 115200, MAX3107_BRG13_IB115200 }, + { 230400, MAX3107_BRG13_IB230400 }, + { 460800, MAX3107_BRG13_IB460800 }, + { 921600, MAX3107_BRG13_IB921600 }, + { 0, 0 } +}; + +static u32 get_new_brg(int baud, struct max3107_port *s) +{ + int i; + const struct baud_table *baud_tbl = s->baud_tbl; + + for (i = 0; i < 13; i++) { + if (baud == baud_tbl[i].baud) + return baud_tbl[i].new_brg; + } + + return 0; +} + +/* Perform SPI transfer for write/read of device register(s) */ +int max3107_rw(struct max3107_port *s, u8 *tx, u8 *rx, int len) +{ + struct spi_message spi_msg; + struct spi_transfer spi_xfer; + + /* Initialize SPI ,message */ + spi_message_init(&spi_msg); + + /* Initialize SPI transfer */ + memset(&spi_xfer, 0, sizeof spi_xfer); + spi_xfer.len = len; + spi_xfer.tx_buf = tx; + spi_xfer.rx_buf = rx; + spi_xfer.speed_hz = MAX3107_SPI_SPEED; + + /* Add SPI transfer to SPI message */ + spi_message_add_tail(&spi_xfer, &spi_msg); + +#ifdef DBG_TRACE_SPI_DATA + { + int i; + pr_info("tx len %d:\n", spi_xfer.len); + for (i = 0 ; i < spi_xfer.len && i < 32 ; i++) + pr_info(" %x", ((u8 *)spi_xfer.tx_buf)[i]); + pr_info("\n"); + } +#endif + + /* Perform synchronous SPI transfer */ + if (spi_sync(s->spi, &spi_msg)) { + dev_err(&s->spi->dev, "spi_sync failure\n"); + return -EIO; + } + +#ifdef DBG_TRACE_SPI_DATA + if (spi_xfer.rx_buf) { + int i; + pr_info("rx len %d:\n", spi_xfer.len); + for (i = 0 ; i < spi_xfer.len && i < 32 ; i++) + pr_info(" %x", ((u8 *)spi_xfer.rx_buf)[i]); + pr_info("\n"); + } +#endif + return 0; +} +EXPORT_SYMBOL_GPL(max3107_rw); + +/* Puts received data to circular buffer */ +static void put_data_to_circ_buf(struct max3107_port *s, unsigned char *data, + int len) +{ + struct uart_port *port = &s->port; + struct tty_struct *tty; + + if (!port->state) + return; + + tty = port->state->port.tty; + if (!tty) + return; + + /* Insert received data */ + tty_insert_flip_string(tty, data, len); + /* Update RX counter */ + port->icount.rx += len; +} + +/* Handle data receiving */ +static void max3107_handlerx(struct max3107_port *s, u16 rxlvl) +{ + int i; + int j; + int len; /* SPI transfer buffer length */ + u16 *buf; + u8 *valid_str; + + if (!s->rx_enabled) + /* RX is disabled */ + return; + + if (rxlvl == 0) { + /* RX fifo is empty */ + return; + } else if (rxlvl >= MAX3107_RX_FIFO_SIZE) { + dev_warn(&s->spi->dev, "Possible RX FIFO overrun %d\n", rxlvl); + /* Ensure sanity of RX level */ + rxlvl = MAX3107_RX_FIFO_SIZE; + } + if ((s->rxbuf == 0) || (s->rxstr == 0)) { + dev_warn(&s->spi->dev, "Rx buffer/str isn't ready\n"); + return; + } + buf = s->rxbuf; + valid_str = s->rxstr; + while (rxlvl) { + pr_debug("rxlvl %d\n", rxlvl); + /* Clear buffer */ + memset(buf, 0, sizeof(u16) * (MAX3107_RX_FIFO_SIZE + 2)); + len = 0; + if (s->irqen_reg & MAX3107_IRQ_RXFIFO_BIT) { + /* First disable RX FIFO interrupt */ + pr_debug("Disabling RX INT\n"); + buf[0] = (MAX3107_WRITE_BIT | MAX3107_IRQEN_REG); + s->irqen_reg &= ~MAX3107_IRQ_RXFIFO_BIT; + buf[0] |= s->irqen_reg; + len++; + } + /* Just increase the length by amount of words in FIFO since + * buffer was zeroed and SPI transfer of 0x0000 means reading + * from RX FIFO + */ + len += rxlvl; + /* Append RX level query */ + buf[len] = MAX3107_RXFIFOLVL_REG; + len++; + + /* Perform the SPI transfer */ + if (max3107_rw(s, (u8 *)buf, (u8 *)buf, len * 2)) { + dev_err(&s->spi->dev, "SPI transfer for RX h failed\n"); + return; + } + + /* Skip RX FIFO interrupt disabling word if it was added */ + j = ((len - 1) - rxlvl); + /* Read received words */ + for (i = 0; i < rxlvl; i++, j++) + valid_str[i] = (u8)buf[j]; + put_data_to_circ_buf(s, valid_str, rxlvl); + /* Get new RX level */ + rxlvl = (buf[len - 1] & MAX3107_SPI_RX_DATA_MASK); + } + + if (s->rx_enabled) { + /* RX still enabled, re-enable RX FIFO interrupt */ + pr_debug("Enabling RX INT\n"); + buf[0] = (MAX3107_WRITE_BIT | MAX3107_IRQEN_REG); + s->irqen_reg |= MAX3107_IRQ_RXFIFO_BIT; + buf[0] |= s->irqen_reg; + if (max3107_rw(s, (u8 *)buf, NULL, 2)) + dev_err(&s->spi->dev, "RX FIFO INT enabling failed\n"); + } + + /* Push the received data to receivers */ + if (s->port.state->port.tty) + tty_flip_buffer_push(s->port.state->port.tty); +} + + +/* Handle data sending */ +static void max3107_handletx(struct max3107_port *s) +{ + struct circ_buf *xmit = &s->port.state->xmit; + int i; + unsigned long flags; + int len; /* SPI transfer buffer length */ + u16 *buf; + + if (!s->tx_fifo_empty) + /* Don't send more data before previous data is sent */ + return; + + if (uart_circ_empty(xmit) || uart_tx_stopped(&s->port)) + /* No data to send or TX is stopped */ + return; + + if (!s->txbuf) { + dev_warn(&s->spi->dev, "Txbuf isn't ready\n"); + return; + } + buf = s->txbuf; + /* Get length of data pending in circular buffer */ + len = uart_circ_chars_pending(xmit); + if (len) { + /* Limit to size of TX FIFO */ + if (len > MAX3107_TX_FIFO_SIZE) + len = MAX3107_TX_FIFO_SIZE; + + pr_debug("txlen %d\n", len); + + /* Update TX counter */ + s->port.icount.tx += len; + + /* TX FIFO will no longer be empty */ + s->tx_fifo_empty = 0; + + i = 0; + if (s->irqen_reg & MAX3107_IRQ_TXEMPTY_BIT) { + /* First disable TX empty interrupt */ + pr_debug("Disabling TE INT\n"); + buf[i] = (MAX3107_WRITE_BIT | MAX3107_IRQEN_REG); + s->irqen_reg &= ~MAX3107_IRQ_TXEMPTY_BIT; + buf[i] |= s->irqen_reg; + i++; + len++; + } + /* Add data to send */ + spin_lock_irqsave(&s->port.lock, flags); + for ( ; i < len ; i++) { + buf[i] = (MAX3107_WRITE_BIT | MAX3107_THR_REG); + buf[i] |= ((u16)xmit->buf[xmit->tail] & + MAX3107_SPI_TX_DATA_MASK); + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + } + spin_unlock_irqrestore(&s->port.lock, flags); + if (!(s->irqen_reg & MAX3107_IRQ_TXEMPTY_BIT)) { + /* Enable TX empty interrupt */ + pr_debug("Enabling TE INT\n"); + buf[i] = (MAX3107_WRITE_BIT | MAX3107_IRQEN_REG); + s->irqen_reg |= MAX3107_IRQ_TXEMPTY_BIT; + buf[i] |= s->irqen_reg; + i++; + len++; + } + if (!s->tx_enabled) { + /* Enable TX */ + pr_debug("Enable TX\n"); + buf[i] = (MAX3107_WRITE_BIT | MAX3107_MODE1_REG); + spin_lock_irqsave(&s->data_lock, flags); + s->mode1_reg &= ~MAX3107_MODE1_TXDIS_BIT; + buf[i] |= s->mode1_reg; + spin_unlock_irqrestore(&s->data_lock, flags); + s->tx_enabled = 1; + i++; + len++; + } + + /* Perform the SPI transfer */ + if (max3107_rw(s, (u8 *)buf, NULL, len*2)) { + dev_err(&s->spi->dev, + "SPI transfer TX handling failed\n"); + return; + } + } + + /* Indicate wake up if circular buffer is getting low on data */ + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(&s->port); + +} + +/* Handle interrupts + * Also reads and returns current RX FIFO level + */ +static u16 handle_interrupt(struct max3107_port *s) +{ + u16 buf[4]; /* Buffer for SPI transfers */ + u8 irq_status; + u16 rx_level; + unsigned long flags; + + /* Read IRQ status register */ + buf[0] = MAX3107_IRQSTS_REG; + /* Read status IRQ status register */ + buf[1] = MAX3107_STS_IRQSTS_REG; + /* Read LSR IRQ status register */ + buf[2] = MAX3107_LSR_IRQSTS_REG; + /* Query RX level */ + buf[3] = MAX3107_RXFIFOLVL_REG; + + if (max3107_rw(s, (u8 *)buf, (u8 *)buf, 8)) { + dev_err(&s->spi->dev, + "SPI transfer for INTR handling failed\n"); + return 0; + } + + irq_status = (u8)buf[0]; + pr_debug("IRQSTS %x\n", irq_status); + rx_level = (buf[3] & MAX3107_SPI_RX_DATA_MASK); + + if (irq_status & MAX3107_IRQ_LSR_BIT) { + /* LSR interrupt */ + if (buf[2] & MAX3107_LSR_RXTO_BIT) + /* RX timeout interrupt, + * handled by normal RX handling + */ + pr_debug("RX TO INT\n"); + } + + if (irq_status & MAX3107_IRQ_TXEMPTY_BIT) { + /* Tx empty interrupt, + * disable TX and set tx_fifo_empty flag + */ + pr_debug("TE INT, disabling TX\n"); + buf[0] = (MAX3107_WRITE_BIT | MAX3107_MODE1_REG); + spin_lock_irqsave(&s->data_lock, flags); + s->mode1_reg |= MAX3107_MODE1_TXDIS_BIT; + buf[0] |= s->mode1_reg; + spin_unlock_irqrestore(&s->data_lock, flags); + if (max3107_rw(s, (u8 *)buf, NULL, 2)) + dev_err(&s->spi->dev, "SPI transfer TX dis failed\n"); + s->tx_enabled = 0; + s->tx_fifo_empty = 1; + } + + if (irq_status & MAX3107_IRQ_RXFIFO_BIT) + /* RX FIFO interrupt, + * handled by normal RX handling + */ + pr_debug("RFIFO INT\n"); + + /* Return RX level */ + return rx_level; +} + +/* Trigger work thread*/ +static void max3107_dowork(struct max3107_port *s) +{ + if (!work_pending(&s->work) && !freezing(current) && !s->suspended) + queue_work(s->workqueue, &s->work); + else + dev_warn(&s->spi->dev, "interrup isn't serviced normally!\n"); +} + +/* Work thread */ +static void max3107_work(struct work_struct *w) +{ + struct max3107_port *s = container_of(w, struct max3107_port, work); + u16 rxlvl = 0; + int len; /* SPI transfer buffer length */ + u16 buf[5]; /* Buffer for SPI transfers */ + unsigned long flags; + + /* Start by reading current RX FIFO level */ + buf[0] = MAX3107_RXFIFOLVL_REG; + if (max3107_rw(s, (u8 *)buf, (u8 *)buf, 2)) { + dev_err(&s->spi->dev, "SPI transfer RX lev failed\n"); + rxlvl = 0; + } else { + rxlvl = (buf[0] & MAX3107_SPI_RX_DATA_MASK); + } + + do { + pr_debug("rxlvl %d\n", rxlvl); + + /* Handle RX */ + max3107_handlerx(s, rxlvl); + rxlvl = 0; + + if (s->handle_irq) { + /* Handle pending interrupts + * We also get new RX FIFO level since new data may + * have been received while pushing received data to + * receivers + */ + s->handle_irq = 0; + rxlvl = handle_interrupt(s); + } + + /* Handle TX */ + max3107_handletx(s); + + /* Handle configuration changes */ + len = 0; + spin_lock_irqsave(&s->data_lock, flags); + if (s->mode1_commit) { + pr_debug("mode1_commit\n"); + buf[len] = (MAX3107_WRITE_BIT | MAX3107_MODE1_REG); + buf[len++] |= s->mode1_reg; + s->mode1_commit = 0; + } + if (s->lcr_commit) { + pr_debug("lcr_commit\n"); + buf[len] = (MAX3107_WRITE_BIT | MAX3107_LCR_REG); + buf[len++] |= s->lcr_reg; + s->lcr_commit = 0; + } + if (s->brg_commit) { + pr_debug("brg_commit\n"); + buf[len] = (MAX3107_WRITE_BIT | MAX3107_BRGDIVMSB_REG); + buf[len++] |= ((s->brg_cfg >> 16) & + MAX3107_SPI_TX_DATA_MASK); + buf[len] = (MAX3107_WRITE_BIT | MAX3107_BRGDIVLSB_REG); + buf[len++] |= ((s->brg_cfg >> 8) & + MAX3107_SPI_TX_DATA_MASK); + buf[len] = (MAX3107_WRITE_BIT | MAX3107_BRGCFG_REG); + buf[len++] |= ((s->brg_cfg) & 0xff); + s->brg_commit = 0; + } + spin_unlock_irqrestore(&s->data_lock, flags); + + if (len > 0) { + if (max3107_rw(s, (u8 *)buf, NULL, len * 2)) + dev_err(&s->spi->dev, + "SPI transfer config failed\n"); + } + + /* Reloop if interrupt handling indicated data in RX FIFO */ + } while (rxlvl); + +} + +/* Set sleep mode */ +static void max3107_set_sleep(struct max3107_port *s, int mode) +{ + u16 buf[1]; /* Buffer for SPI transfer */ + unsigned long flags; + pr_debug("enter, mode %d\n", mode); + + buf[0] = (MAX3107_WRITE_BIT | MAX3107_MODE1_REG); + spin_lock_irqsave(&s->data_lock, flags); + switch (mode) { + case MAX3107_DISABLE_FORCED_SLEEP: + s->mode1_reg &= ~MAX3107_MODE1_FORCESLEEP_BIT; + break; + case MAX3107_ENABLE_FORCED_SLEEP: + s->mode1_reg |= MAX3107_MODE1_FORCESLEEP_BIT; + break; + case MAX3107_DISABLE_AUTOSLEEP: + s->mode1_reg &= ~MAX3107_MODE1_AUTOSLEEP_BIT; + break; + case MAX3107_ENABLE_AUTOSLEEP: + s->mode1_reg |= MAX3107_MODE1_AUTOSLEEP_BIT; + break; + default: + spin_unlock_irqrestore(&s->data_lock, flags); + dev_warn(&s->spi->dev, "invalid sleep mode\n"); + return; + } + buf[0] |= s->mode1_reg; + spin_unlock_irqrestore(&s->data_lock, flags); + + if (max3107_rw(s, (u8 *)buf, NULL, 2)) + dev_err(&s->spi->dev, "SPI transfer sleep mode failed\n"); + + if (mode == MAX3107_DISABLE_AUTOSLEEP || + mode == MAX3107_DISABLE_FORCED_SLEEP) + msleep(MAX3107_WAKEUP_DELAY); +} + +/* Perform full register initialization */ +static void max3107_register_init(struct max3107_port *s) +{ + u16 buf[11]; /* Buffer for SPI transfers */ + + /* 1. Configure baud rate, 9600 as default */ + s->baud = 9600; + /* the below is default*/ + if (s->ext_clk) { + s->brg_cfg = MAX3107_BRG26_B9600; + s->baud_tbl = (struct baud_table *)brg26_ext; + } else { + s->brg_cfg = MAX3107_BRG13_IB9600; + s->baud_tbl = (struct baud_table *)brg13_int; + } + + if (s->pdata->init) + s->pdata->init(s); + + buf[0] = (MAX3107_WRITE_BIT | MAX3107_BRGDIVMSB_REG) + | ((s->brg_cfg >> 16) & MAX3107_SPI_TX_DATA_MASK); + buf[1] = (MAX3107_WRITE_BIT | MAX3107_BRGDIVLSB_REG) + | ((s->brg_cfg >> 8) & MAX3107_SPI_TX_DATA_MASK); + buf[2] = (MAX3107_WRITE_BIT | MAX3107_BRGCFG_REG) + | ((s->brg_cfg) & 0xff); + + /* 2. Configure LCR register, 8N1 mode by default */ + s->lcr_reg = MAX3107_LCR_WORD_LEN_8; + buf[3] = (MAX3107_WRITE_BIT | MAX3107_LCR_REG) + | s->lcr_reg; + + /* 3. Configure MODE 1 register */ + s->mode1_reg = 0; + /* Enable IRQ pin */ + s->mode1_reg |= MAX3107_MODE1_IRQSEL_BIT; + /* Disable TX */ + s->mode1_reg |= MAX3107_MODE1_TXDIS_BIT; + s->tx_enabled = 0; + /* RX is enabled */ + s->rx_enabled = 1; + buf[4] = (MAX3107_WRITE_BIT | MAX3107_MODE1_REG) + | s->mode1_reg; + + /* 4. Configure MODE 2 register */ + buf[5] = (MAX3107_WRITE_BIT | MAX3107_MODE2_REG); + if (s->loopback) { + /* Enable loopback */ + buf[5] |= MAX3107_MODE2_LOOPBACK_BIT; + } + /* Reset FIFOs */ + buf[5] |= MAX3107_MODE2_FIFORST_BIT; + s->tx_fifo_empty = 1; + + /* 5. Configure FIFO trigger level register */ + buf[6] = (MAX3107_WRITE_BIT | MAX3107_FIFOTRIGLVL_REG); + /* RX FIFO trigger for 16 words, TX FIFO trigger not used */ + buf[6] |= (MAX3107_FIFOTRIGLVL_RX(16) | MAX3107_FIFOTRIGLVL_TX(0)); + + /* 6. Configure flow control levels */ + buf[7] = (MAX3107_WRITE_BIT | MAX3107_FLOWLVL_REG); + /* Flow control halt level 96, resume level 48 */ + buf[7] |= (MAX3107_FLOWLVL_RES(48) | MAX3107_FLOWLVL_HALT(96)); + + /* 7. Configure flow control */ + buf[8] = (MAX3107_WRITE_BIT | MAX3107_FLOWCTRL_REG); + /* Enable auto CTS and auto RTS flow control */ + buf[8] |= (MAX3107_FLOWCTRL_AUTOCTS_BIT | MAX3107_FLOWCTRL_AUTORTS_BIT); + + /* 8. Configure RX timeout register */ + buf[9] = (MAX3107_WRITE_BIT | MAX3107_RXTO_REG); + /* Timeout after 48 character intervals */ + buf[9] |= 0x0030; + + /* 9. Configure LSR interrupt enable register */ + buf[10] = (MAX3107_WRITE_BIT | MAX3107_LSR_IRQEN_REG); + /* Enable RX timeout interrupt */ + buf[10] |= MAX3107_LSR_RXTO_BIT; + + /* Perform SPI transfer */ + if (max3107_rw(s, (u8 *)buf, NULL, 22)) + dev_err(&s->spi->dev, "SPI transfer for init failed\n"); + + /* 10. Clear IRQ status register by reading it */ + buf[0] = MAX3107_IRQSTS_REG; + + /* 11. Configure interrupt enable register */ + /* Enable LSR interrupt */ + s->irqen_reg = MAX3107_IRQ_LSR_BIT; + /* Enable RX FIFO interrupt */ + s->irqen_reg |= MAX3107_IRQ_RXFIFO_BIT; + buf[1] = (MAX3107_WRITE_BIT | MAX3107_IRQEN_REG) + | s->irqen_reg; + + /* 12. Clear FIFO reset that was set in step 6 */ + buf[2] = (MAX3107_WRITE_BIT | MAX3107_MODE2_REG); + if (s->loopback) { + /* Keep loopback enabled */ + buf[2] |= MAX3107_MODE2_LOOPBACK_BIT; + } + + /* Perform SPI transfer */ + if (max3107_rw(s, (u8 *)buf, (u8 *)buf, 6)) + dev_err(&s->spi->dev, "SPI transfer for init failed\n"); + +} + +/* IRQ handler */ +static irqreturn_t max3107_irq(int irqno, void *dev_id) +{ + struct max3107_port *s = dev_id; + + if (irqno != s->spi->irq) { + /* Unexpected IRQ */ + return IRQ_NONE; + } + + /* Indicate irq */ + s->handle_irq = 1; + + /* Trigger work thread */ + max3107_dowork(s); + + return IRQ_HANDLED; +} + +/* HW suspension function + * + * Currently autosleep is used to decrease current consumption, alternative + * approach would be to set the chip to reset mode if UART is not being + * used but that would mess the GPIOs + * + */ +void max3107_hw_susp(struct max3107_port *s, int suspend) +{ + pr_debug("enter, suspend %d\n", suspend); + + if (suspend) { + /* Suspend requested, + * enable autosleep to decrease current consumption + */ + s->suspended = 1; + max3107_set_sleep(s, MAX3107_ENABLE_AUTOSLEEP); + } else { + /* Resume requested, + * disable autosleep + */ + s->suspended = 0; + max3107_set_sleep(s, MAX3107_DISABLE_AUTOSLEEP); + } +} +EXPORT_SYMBOL_GPL(max3107_hw_susp); + +/* Modem status IRQ enabling */ +static void max3107_enable_ms(struct uart_port *port) +{ + /* Modem status not supported */ +} + +/* Data send function */ +static void max3107_start_tx(struct uart_port *port) +{ + struct max3107_port *s = container_of(port, struct max3107_port, port); + + /* Trigger work thread for sending data */ + max3107_dowork(s); +} + +/* Function for checking that there is no pending transfers */ +static unsigned int max3107_tx_empty(struct uart_port *port) +{ + struct max3107_port *s = container_of(port, struct max3107_port, port); + + pr_debug("returning %d\n", + (s->tx_fifo_empty && uart_circ_empty(&s->port.state->xmit))); + return s->tx_fifo_empty && uart_circ_empty(&s->port.state->xmit); +} + +/* Function for stopping RX */ +static void max3107_stop_rx(struct uart_port *port) +{ + struct max3107_port *s = container_of(port, struct max3107_port, port); + unsigned long flags; + + /* Set RX disabled in MODE 1 register */ + spin_lock_irqsave(&s->data_lock, flags); + s->mode1_reg |= MAX3107_MODE1_RXDIS_BIT; + s->mode1_commit = 1; + spin_unlock_irqrestore(&s->data_lock, flags); + /* Set RX disabled */ + s->rx_enabled = 0; + /* Trigger work thread for doing the actual configuration change */ + max3107_dowork(s); +} + +/* Function for returning control pin states */ +static unsigned int max3107_get_mctrl(struct uart_port *port) +{ + /* DCD and DSR are not wired and CTS/RTS is handled automatically + * so just indicate DSR and CAR asserted + */ + return TIOCM_DSR | TIOCM_CAR; +} + +/* Function for setting control pin states */ +static void max3107_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + /* DCD and DSR are not wired and CTS/RTS is hadnled automatically + * so do nothing + */ +} + +/* Function for configuring UART parameters */ +static void max3107_set_termios(struct uart_port *port, + struct ktermios *termios, + struct ktermios *old) +{ + struct max3107_port *s = container_of(port, struct max3107_port, port); + struct tty_struct *tty; + int baud; + u16 new_lcr = 0; + u32 new_brg = 0; + unsigned long flags; + + if (!port->state) + return; + + tty = port->state->port.tty; + if (!tty) + return; + + /* Get new LCR register values */ + /* Word size */ + if ((termios->c_cflag & CSIZE) == CS7) + new_lcr |= MAX3107_LCR_WORD_LEN_7; + else + new_lcr |= MAX3107_LCR_WORD_LEN_8; + + /* Parity */ + if (termios->c_cflag & PARENB) { + new_lcr |= MAX3107_LCR_PARITY_BIT; + if (!(termios->c_cflag & PARODD)) + new_lcr |= MAX3107_LCR_EVENPARITY_BIT; + } + + /* Stop bits */ + if (termios->c_cflag & CSTOPB) { + /* 2 stop bits */ + new_lcr |= MAX3107_LCR_STOPLEN_BIT; + } + + /* Mask termios capabilities we don't support */ + termios->c_cflag &= ~CMSPAR; + + /* Set status ignore mask */ + s->port.ignore_status_mask = 0; + if (termios->c_iflag & IGNPAR) + s->port.ignore_status_mask |= MAX3107_ALL_ERRORS; + + /* Set low latency to immediately handle pushed data */ + s->port.state->port.tty->low_latency = 1; + + /* Get new baud rate generator configuration */ + baud = tty_get_baud_rate(tty); + + spin_lock_irqsave(&s->data_lock, flags); + new_brg = get_new_brg(baud, s); + /* if can't find the corrent config, use previous */ + if (!new_brg) { + baud = s->baud; + new_brg = s->brg_cfg; + } + spin_unlock_irqrestore(&s->data_lock, flags); + tty_termios_encode_baud_rate(termios, baud, baud); + s->baud = baud; + + /* Update timeout according to new baud rate */ + uart_update_timeout(port, termios->c_cflag, baud); + + spin_lock_irqsave(&s->data_lock, flags); + if (s->lcr_reg != new_lcr) { + s->lcr_reg = new_lcr; + s->lcr_commit = 1; + } + if (s->brg_cfg != new_brg) { + s->brg_cfg = new_brg; + s->brg_commit = 1; + } + spin_unlock_irqrestore(&s->data_lock, flags); + + /* Trigger work thread for doing the actual configuration change */ + max3107_dowork(s); +} + +/* Port shutdown function */ +static void max3107_shutdown(struct uart_port *port) +{ + struct max3107_port *s = container_of(port, struct max3107_port, port); + + if (s->suspended && s->pdata->hw_suspend) + s->pdata->hw_suspend(s, 0); + + /* Free the interrupt */ + free_irq(s->spi->irq, s); + + if (s->workqueue) { + /* Flush and destroy work queue */ + flush_workqueue(s->workqueue); + destroy_workqueue(s->workqueue); + s->workqueue = NULL; + } + + /* Suspend HW */ + if (s->pdata->hw_suspend) + s->pdata->hw_suspend(s, 1); +} + +/* Port startup function */ +static int max3107_startup(struct uart_port *port) +{ + struct max3107_port *s = container_of(port, struct max3107_port, port); + + /* Initialize work queue */ + s->workqueue = create_freezeable_workqueue("max3107"); + if (!s->workqueue) { + dev_err(&s->spi->dev, "Workqueue creation failed\n"); + return -EBUSY; + } + INIT_WORK(&s->work, max3107_work); + + /* Setup IRQ */ + if (request_irq(s->spi->irq, max3107_irq, IRQF_TRIGGER_FALLING, + "max3107", s)) { + dev_err(&s->spi->dev, "IRQ reguest failed\n"); + destroy_workqueue(s->workqueue); + s->workqueue = NULL; + return -EBUSY; + } + + /* Resume HW */ + if (s->pdata->hw_suspend) + s->pdata->hw_suspend(s, 0); + + /* Init registers */ + max3107_register_init(s); + + return 0; +} + +/* Port type function */ +static const char *max3107_type(struct uart_port *port) +{ + struct max3107_port *s = container_of(port, struct max3107_port, port); + return s->spi->modalias; +} + +/* Port release function */ +static void max3107_release_port(struct uart_port *port) +{ + /* Do nothing */ +} + +/* Port request function */ +static int max3107_request_port(struct uart_port *port) +{ + /* Do nothing */ + return 0; +} + +/* Port config function */ +static void max3107_config_port(struct uart_port *port, int flags) +{ + struct max3107_port *s = container_of(port, struct max3107_port, port); + s->port.type = PORT_MAX3107; +} + +/* Port verify function */ +static int max3107_verify_port(struct uart_port *port, + struct serial_struct *ser) +{ + if (ser->type == PORT_UNKNOWN || ser->type == PORT_MAX3107) + return 0; + + return -EINVAL; +} + +/* Port stop TX function */ +static void max3107_stop_tx(struct uart_port *port) +{ + /* Do nothing */ +} + +/* Port break control function */ +static void max3107_break_ctl(struct uart_port *port, int break_state) +{ + /* We don't support break control, do nothing */ +} + + +/* Port functions */ +static struct uart_ops max3107_ops = { + .tx_empty = max3107_tx_empty, + .set_mctrl = max3107_set_mctrl, + .get_mctrl = max3107_get_mctrl, + .stop_tx = max3107_stop_tx, + .start_tx = max3107_start_tx, + .stop_rx = max3107_stop_rx, + .enable_ms = max3107_enable_ms, + .break_ctl = max3107_break_ctl, + .startup = max3107_startup, + .shutdown = max3107_shutdown, + .set_termios = max3107_set_termios, + .type = max3107_type, + .release_port = max3107_release_port, + .request_port = max3107_request_port, + .config_port = max3107_config_port, + .verify_port = max3107_verify_port, +}; + +/* UART driver data */ +static struct uart_driver max3107_uart_driver = { + .owner = THIS_MODULE, + .driver_name = "ttyMAX", + .dev_name = "ttyMAX", + .nr = 1, +}; + +static int driver_registered = 0; + + + +/* 'Generic' platform data */ +static struct max3107_plat generic_plat_data = { + .loopback = 0, + .ext_clk = 1, + .hw_suspend = max3107_hw_susp, + .polled_mode = 0, + .poll_time = 0, +}; + + +/*******************************************************************/ + +/** + * max3107_probe - SPI bus probe entry point + * @spi: the spi device + * + * SPI wants us to probe this device and if appropriate claim it. + * Perform any platform specific requirements and then initialise + * the device. + */ + +int max3107_probe(struct spi_device *spi, struct max3107_plat *pdata) +{ + struct max3107_port *s; + u16 buf[2]; /* Buffer for SPI transfers */ + int retval; + + pr_info("enter max3107 probe\n"); + + /* Allocate port structure */ + s = kzalloc(sizeof(*s), GFP_KERNEL); + if (!s) { + pr_err("Allocating port structure failed\n"); + return -ENOMEM; + } + + s->pdata = pdata; + + /* SPI Rx buffer + * +2 for RX FIFO interrupt + * disabling and RX level query + */ + s->rxbuf = kzalloc(sizeof(u16) * (MAX3107_RX_FIFO_SIZE+2), GFP_KERNEL); + if (!s->rxbuf) { + pr_err("Allocating RX buffer failed\n"); + return -ENOMEM; + } + s->rxstr = kzalloc(sizeof(u8) * MAX3107_RX_FIFO_SIZE, GFP_KERNEL); + if (!s->rxstr) { + pr_err("Allocating RX buffer failed\n"); + return -ENOMEM; + } + /* SPI Tx buffer + * SPI transfer buffer + * +3 for TX FIFO empty + * interrupt disabling and + * enabling and TX enabling + */ + s->txbuf = kzalloc(sizeof(u16) * MAX3107_TX_FIFO_SIZE + 3, GFP_KERNEL); + if (!s->txbuf) { + pr_err("Allocating TX buffer failed\n"); + return -ENOMEM; + } + /* Initialize shared data lock */ + spin_lock_init(&s->data_lock); + + /* SPI intializations */ + dev_set_drvdata(&spi->dev, s); + spi->mode = SPI_MODE_0; + spi->dev.platform_data = pdata; + spi->bits_per_word = 16; + s->ext_clk = pdata->ext_clk; + s->loopback = pdata->loopback; + spi_setup(spi); + s->spi = spi; + + /* Check REV ID to ensure we are talking to what we expect */ + buf[0] = MAX3107_REVID_REG; + if (max3107_rw(s, (u8 *)buf, (u8 *)buf, 2)) { + dev_err(&s->spi->dev, "SPI transfer for REVID read failed\n"); + return -EIO; + } + if ((buf[0] & MAX3107_SPI_RX_DATA_MASK) != MAX3107_REVID1 && + (buf[0] & MAX3107_SPI_RX_DATA_MASK) != MAX3107_REVID2) { + dev_err(&s->spi->dev, "REVID %x does not match\n", + (buf[0] & MAX3107_SPI_RX_DATA_MASK)); + return -ENODEV; + } + + /* Disable all interrupts */ + buf[0] = (MAX3107_WRITE_BIT | MAX3107_IRQEN_REG | 0x0000); + buf[0] |= 0x0000; + + /* Configure clock source */ + buf[1] = (MAX3107_WRITE_BIT | MAX3107_CLKSRC_REG); + if (s->ext_clk) { + /* External clock */ + buf[1] |= MAX3107_CLKSRC_EXTCLK_BIT; + } + + /* PLL bypass ON */ + buf[1] |= MAX3107_CLKSRC_PLLBYP_BIT; + + /* Perform SPI transfer */ + if (max3107_rw(s, (u8 *)buf, NULL, 4)) { + dev_err(&s->spi->dev, "SPI transfer for init failed\n"); + return -EIO; + } + + /* Register UART driver */ + if (!driver_registered) { + retval = uart_register_driver(&max3107_uart_driver); + if (retval) { + dev_err(&s->spi->dev, "Registering UART driver failed\n"); + return retval; + } + driver_registered = 1; + } + + /* Initialize UART port data */ + s->port.fifosize = 128; + s->port.ops = &max3107_ops; + s->port.line = 0; + s->port.dev = &spi->dev; + s->port.uartclk = 9600; + s->port.flags = UPF_SKIP_TEST | UPF_BOOT_AUTOCONF; + s->port.irq = s->spi->irq; + s->port.type = PORT_MAX3107; + + /* Add UART port */ + retval = uart_add_one_port(&max3107_uart_driver, &s->port); + if (retval < 0) { + dev_err(&s->spi->dev, "Adding UART port failed\n"); + return retval; + } + + if (pdata->configure) { + retval = pdata->configure(s); + if (retval < 0) + return retval; + } + + /* Go to suspend mode */ + if (pdata->hw_suspend) + pdata->hw_suspend(s, 1); + + return 0; +} +EXPORT_SYMBOL_GPL(max3107_probe); + +/* Driver remove function */ +int max3107_remove(struct spi_device *spi) +{ + struct max3107_port *s = dev_get_drvdata(&spi->dev); + + pr_info("enter max3107 remove\n"); + + /* Remove port */ + if (uart_remove_one_port(&max3107_uart_driver, &s->port)) + dev_warn(&s->spi->dev, "Removing UART port failed\n"); + + + /* Free TxRx buffer */ + kfree(s->rxbuf); + kfree(s->rxstr); + kfree(s->txbuf); + + /* Free port structure */ + kfree(s); + + return 0; +} +EXPORT_SYMBOL_GPL(max3107_remove); + +/* Driver suspend function */ +int max3107_suspend(struct spi_device *spi, pm_message_t state) +{ +#ifdef CONFIG_PM + struct max3107_port *s = dev_get_drvdata(&spi->dev); + + pr_debug("enter suspend\n"); + + /* Suspend UART port */ + uart_suspend_port(&max3107_uart_driver, &s->port); + + /* Go to suspend mode */ + if (s->pdata->hw_suspend) + s->pdata->hw_suspend(s, 1); +#endif /* CONFIG_PM */ + return 0; +} +EXPORT_SYMBOL_GPL(max3107_suspend); + +/* Driver resume function */ +int max3107_resume(struct spi_device *spi) +{ +#ifdef CONFIG_PM + struct max3107_port *s = dev_get_drvdata(&spi->dev); + + pr_debug("enter resume\n"); + + /* Resume from suspend */ + if (s->pdata->hw_suspend) + s->pdata->hw_suspend(s, 0); + + /* Resume UART port */ + uart_resume_port(&max3107_uart_driver, &s->port); +#endif /* CONFIG_PM */ + return 0; +} +EXPORT_SYMBOL_GPL(max3107_resume); + +static int max3107_probe_generic(struct spi_device *spi) +{ + return max3107_probe(spi, &generic_plat_data); +} + +/* Spi driver data */ +static struct spi_driver max3107_driver = { + .driver = { + .name = "max3107", + .bus = &spi_bus_type, + .owner = THIS_MODULE, + }, + .probe = max3107_probe_generic, + .remove = __devexit_p(max3107_remove), + .suspend = max3107_suspend, + .resume = max3107_resume, +}; + +/* Driver init function */ +static int __init max3107_init(void) +{ + pr_info("enter max3107 init\n"); + return spi_register_driver(&max3107_driver); +} + +/* Driver exit function */ +static void __exit max3107_exit(void) +{ + pr_info("enter max3107 exit\n"); + /* Unregister UART driver */ + if (driver_registered) + uart_unregister_driver(&max3107_uart_driver); + spi_unregister_driver(&max3107_driver); +} + +module_init(max3107_init); +module_exit(max3107_exit); + +MODULE_DESCRIPTION("MAX3107 driver"); +MODULE_AUTHOR("Aavamobile"); +MODULE_ALIAS("max3107-spi"); +MODULE_LICENSE("GPL v2"); |