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linux-next/drivers/serial/max3107.c
Alan Cox 61fd15262b serial: max3107: Abstract out the platform specific bits 
At the moment there is only one platform type supported and there is is
hard wired, but with these changes the infrastructure is now there for
anyone else to provide methods for their hardware.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-10 13:47:44 -07:00

1198 lines
30 KiB
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/*
* 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");
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