static int m_spi_select(lua_State * L)
{
struct lspi_t * spi = luaL_checkudata(L, 1, MT_HARDWARE_SPI);
spi_device_select(spi->dev);
lua_settop(L, 1);
return 1;
}
static void ssd1309_write_command(struct fb_ssd1309_pdata_t * pdat, u8_t cmd)
{
spi_device_select(pdat->dev);
gpio_set_value(pdat->cd, 0);
spi_device_write_then_read(pdat->dev, &cmd, 1, 0, 0);
gpio_set_value(pdat->cd, 1);
spi_device_deselect(pdat->dev);
}
/**
* Perform a SPI read/write transfer using interrupts.
*/
ssize_t spi_transfer(struct spi_bus *bus, struct spi_device *dev,
uint32_t timeout, const uint8_t *tx_buf,
uint8_t *rx_buf, size_t len)
{
bool error = false;
if (len == 0) /* ensure at least one byte of TX/RX */
return 0;
if (xSemaphoreTake(bus->lock, timeout) == pdFALSE)
return -1;
spi_enable(bus, dev);
spi_device_select(dev);
bus->transfer.tx_buf = tx_buf;
bus->transfer.rx_buf = rx_buf;
bus->transfer.tx_len = len;
bus->transfer.rx_len = len;
interrupt_enable(bus->irq);
spi_cr2_set(bus, SPI_CR2_TXEIE | SPI_CR2_ERRIE);
/* XXX We may not be able to successfully communicate on this bus
* after we time out like this without doing something special to
* clear the error state. Most likely we're going to panic anyway,
* though. */
if (!xSemaphoreTake(bus->complete, timeout))
error = true;
spi_cr2_clear(bus, SPI_CR2_TXEIE | SPI_CR2_RXNEIE);
interrupt_disable(bus->irq);
/* According to the reference manual, we must wait until TXE=1 and
* BSY=0 before disabling the SPI. Don't bother doing this if the
* transfer has timed out. */
if (error) {
BUSY_UNTIL_SET(bus->dev->SR, SPI_SR_TXE);
BUSY_UNTIL_CLEAR(bus->dev->SR, SPI_SR_BSY);
}
spi_device_deselect(dev);
spi_disable(bus);
xSemaphoreGive(bus->lock);
return error ? -1 : len - bus->transfer.rx_len;
}
static void ssd1309_write_data(struct fb_ssd1309_pdata_t * pdat, u8_t dat)
{
spi_device_select(pdat->dev);
spi_device_write_then_read(pdat->dev, &dat, 1, 0, 0);
spi_device_deselect(pdat->dev);
}
