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i2c: dw: implement generic transfer functions

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() For interrupt driven transfer, the driver already has
   a generic transfer function, so this simply exposes it
   for public consumption.
() The polling write is extended to support generic
   transfer.

Change-Id: I657db8a6376282c723728b7a875813d389cf7d27
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
This commit is contained in:
Daniel Leung 2015-10-07 17:03:08 -07:00 • committed by Anas Nashif
commit 01796ecf5c
1 changed files with 52 additions and 9 deletions
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57
drivers/i2c/i2c-dw.c
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@ -448,10 +448,10 @@ static int _i2c_dw_transfer_init(struct device *dev,
return DEV_OK;
}
static int _i2c_dw_transfer_start(struct device *dev,
static int i2c_dw_transfer(struct device *dev,
uint8_t *write_buf, uint32_t write_len,
uint8_t *read_buf, uint32_t read_len,
uint16_t slave_address)
uint16_t slave_address, uint32_t flags)
{
struct i2c_dw_rom_config const * const rom = dev->config->config_info;
volatile struct i2c_dw_registers * const regs =
@ -488,9 +488,10 @@ static int _i2c_dw_transfer_start(struct device *dev,
}
#define POLLING_TIMEOUT (sys_clock_ticks_per_sec / 10)
static int i2c_dw_polling_write(struct device *dev,
static int i2c_dw_poll_transfer(struct device *dev,
uint8_t *write_buf, uint32_t write_len,
uint16_t slave_address)
uint8_t *read_buf, uint32_t read_len,
uint16_t slave_address, uint32_t flags)
{
struct i2c_dw_rom_config const * const rom = dev->config->config_info;
struct i2c_dw_dev_config * const dw = dev->driver_data;
@ -514,7 +515,7 @@ static int i2c_dw_polling_write(struct device *dev,
}
ret = _i2c_dw_transfer_init(dev, write_buf, write_len,
NULL, 0, slave_address);
read_buf, read_len, slave_address);
if (ret) {
return ret;
}
@ -522,6 +523,10 @@ static int i2c_dw_polling_write(struct device *dev,
/* Enable controller */
regs->ic_enable.bits.enable = 1;
if (dw->tx_len == 0) {
goto do_receive;
}
/* Transmit */
while (dw->tx_len > 0) {
/* Wait for space in TX FIFO */
@ -536,12 +541,41 @@ static int i2c_dw_polling_write(struct device *dev,
_i2c_dw_data_send(dev);
}
/* Wait for TX FIFO empty to be sure everything is sent. */
start_time = nano_tick_get_32();
while (!regs->ic_status.bits.tfe) {
if ((nano_tick_get_32() - start_time) > POLLING_TIMEOUT) {
ret = DEV_FAIL;
goto finish;
}
}
do_receive:
/* Finalize TX when there is nothing more to send as
* the data send function has code to deal with the end of
* TX phase.
*/
_i2c_dw_data_send(dev);
/* Finish transfer when there is nothing to receive */
if (dw->rx_len == 0) {
goto stop_det;
}
while (dw->rx_len > 0) {
/* Wait for data in RX FIFO*/
start_time = nano_tick_get_32();
while (!regs->ic_status.bits.rfne) {
if ((nano_tick_get_32() - start_time) > POLLING_TIMEOUT) {
ret = DEV_FAIL;
goto finish;
}
}
_i2c_dw_data_read(dev);
}
stop_det:
/* Wait for transfer to complete */
start_time = nano_tick_get_32();
while (!regs->ic_raw_intr_stat.bits.stop_det) {
@ -685,16 +719,23 @@ static int i2c_dw_set_callback(struct device *dev, i2c_callback cb)
static int i2c_dw_write(struct device *dev, uint8_t *buf,
uint32_t len, uint16_t slave_addr)
{
return _i2c_dw_transfer_start(dev, buf, len, 0, 0, slave_addr);
return i2c_dw_transfer(dev, buf, len, 0, 0, slave_addr, 0);
}
static int i2c_dw_read(struct device *dev, uint8_t *buf,
uint32_t len, uint16_t slave_addr)
{
return _i2c_dw_transfer_start(dev, 0, 0, buf, len, slave_addr);
return i2c_dw_transfer(dev, 0, 0, buf, len, slave_addr, 0);
}
static int i2c_dw_polling_write(struct device *dev,
uint8_t *write_buf, uint32_t write_len,
uint16_t slave_address)
{
return i2c_dw_poll_transfer(dev, write_buf, write_len,
0, 0, slave_address, 0);
}
static int i2c_dw_suspend(struct device *dev)
{
@ -717,9 +758,11 @@ static struct i2c_driver_api funcs = {
.set_callback = i2c_dw_set_callback,
.write = i2c_dw_write,
.read = i2c_dw_read,
.transfer = i2c_dw_transfer,
.suspend = i2c_dw_suspend,
.resume = i2c_dw_resume,
.polling_write = i2c_dw_polling_write,
.poll_transfer = i2c_dw_poll_transfer,
};