/**
* @brief Probe SPI device
*
* This function is called by the system to register the driver when the system
* boot up. This function allocates memory for the private SPI device
* information, and then setup the hardware resource and interrupt handler.
*
* @param dev pointer to structure of device data
* @return 0 on success, negative errno on error
*/
static int tsb_spi_dev_probe(struct device *dev)
{
struct tsb_spi_info *info = NULL;
struct device_spi_caps *caps = NULL;
int ret = 0;
if (!dev) {
return -EINVAL;
}
info = zalloc(sizeof(*info));
if (!info) {
return -ENOMEM;
}
info->dev = dev;
info->state = TSB_SPI_STATE_CLOSED;
device_set_private(dev, info);
/* setup spi hardware capabilities */
caps = &info->caps;
caps->modes = SPI_MODE_CPHA |
SPI_MODE_CPOL |
SPI_MODE_CS_HIGH |
SPI_MODE_LSB_FIRST |
SPI_MODE_LOOP;
caps->flags = 0; /* Full Duplex */
caps->bpw = BIT(8-1) | BIT(16-1) | BIT(32-1);
caps->csnum = 1; /* support 1 chipselect */
info->chipselect[0] = SPI_CS;
info->selected = -1; /* select none */
info->bitexchange = tsb_spi_bitexchange0;
/* initialize gpio pins */
tsb_spi_hw_init(dev);
sem_init(&info->bus, 0, 1);
sem_init(&info->lock, 0, 1);
return ret;
}
/**
* @brief Open SPI device
*
* This function is called when the caller is preparing to use this device
* driver. This function should be called after probe() function and needs to
* check whether the driver is already open. If driver was opened, it needs
* to return an error code to the caller.
*
* @param dev pointer to structure of device data
* @return 0 on success, negative errno on error
*/
static int tsb_spi_dev_open(struct device *dev)
{
struct tsb_spi_dev_info *info = NULL;
struct device *spi_board;
int i;
int ret = 0;
/* check input parameter */
if (!dev || !device_get_private(dev)) {
return -EINVAL;
}
info = device_get_private(dev);
sem_wait(&info->lock);
if (info->state != TSB_SPI_STATE_CLOSED) {
ret = -EBUSY;
goto err_open;
}
/* open all the consecutive slaves we can find */
info->num_boards = 0;
for (i = 0; i < SPI_MAX_SLAVES; i++) {
spi_board = device_open(DEVICE_TYPE_SPI_BOARD_HW, i);
if (spi_board) {
info->num_boards++;
info->dev_spi_board[i] = spi_board;
} else
break;
}
info->curr_xfer.cs_high = 0;
info->curr_xfer.bpw = 8;
ret = tsb_spi_hw_init(info);
if (ret) {
goto err_hwinit;
}
/* register SPI IRQ number */
ret = irq_attach(TSB_IRQ_SPI, tsb_spi_irq_handler, NULL);
if (ret != OK) {
ret = -EIO;
goto err_irq;
}
up_enable_irq(TSB_IRQ_SPI);
info->state = TSB_SPI_STATE_OPEN;
sem_post(&info->lock);
return ret;
err_irq:
tsb_spi_hw_deinit(info);
err_hwinit:
for (i = 0; i < info->num_boards; i++) {
device_close(info->dev_spi_board[i]);
info->dev_spi_board[i] = NULL;
}
err_open:
sem_post(&info->lock);
return ret;
}