static int pic32_spi_probe(struct udevice *bus)
{
struct pic32_spi_priv *priv = dev_get_priv(bus);
struct dm_spi_bus *dm_spi = dev_get_uclass_priv(bus);
struct udevice *clkdev;
fdt_addr_t addr;
fdt_size_t size;
int ret;
debug("%s: %d, bus: %i\n", __func__, __LINE__, bus->seq);
addr = fdtdec_get_addr_size(gd->fdt_blob, bus->of_offset, "reg", &size);
if (addr == FDT_ADDR_T_NONE)
return -EINVAL;
priv->regs = ioremap(addr, size);
if (!priv->regs)
return -EINVAL;
dm_spi->max_hz = fdtdec_get_int(gd->fdt_blob, bus->of_offset,
"spi-max-frequency", 250000000);
/* get clock rate */
ret = clk_get_by_index(bus, 0, &clkdev);
if (ret < 0) {
printf("pic32-spi: error, clk not found\n");
return ret;
}
priv->clk_rate = clk_get_periph_rate(clkdev, ret);
/* initialize HW */
pic32_spi_hw_init(priv);
/* set word len */
pic32_spi_set_word_size(priv, SPI_DEFAULT_WORDLEN);
/* PIC32 SPI controller can automatically drive /CS during transfer
* depending on fifo fill-level. /CS will stay asserted as long as
* TX fifo is non-empty, else will be deasserted confirming completion
* of the ongoing transfer. To avoid this sort of error we will drive
* /CS manually by toggling cs-gpio pins.
*/
ret = gpio_request_by_name_nodev(gd->fdt_blob, bus->of_offset,
"cs-gpios", 0,
&priv->cs_gpio, GPIOD_IS_OUT);
if (ret) {
printf("pic32-spi: error, cs-gpios not found\n");
return ret;
}
return 0;
}
static int pic32_spi_prepare_message(struct spi_master *master,
struct spi_message *msg)
{
struct pic32_spi *pic32s = spi_master_get_devdata(master);
struct spi_device *spi = msg->spi;
u32 val;
/* set device specific bits_per_word */
if (pic32s->bits_per_word != spi->bits_per_word) {
pic32_spi_set_word_size(pic32s, spi->bits_per_word);
pic32s->bits_per_word = spi->bits_per_word;
}
/* device specific speed change */
if (pic32s->speed_hz != spi->max_speed_hz) {
pic32_spi_set_clk_rate(pic32s, spi->max_speed_hz);
pic32s->speed_hz = spi->max_speed_hz;
}
/* device specific mode change */
if (pic32s->mode != spi->mode) {
val = readl(&pic32s->regs->ctrl);
/* active low */
if (spi->mode & SPI_CPOL)
val |= CTRL_CKP;
else
val &= ~CTRL_CKP;
/* tx on rising edge */
if (spi->mode & SPI_CPHA)
val &= ~CTRL_CKE;
else
val |= CTRL_CKE;
/* rx at end of tx */
val |= CTRL_SMP;
writel(val, &pic32s->regs->ctrl);
pic32s->mode = spi->mode;
}
return 0;
}
static int pic32_spi_one_transfer(struct spi_master *master,
struct spi_device *spi,
struct spi_transfer *transfer)
{
struct pic32_spi *pic32s;
bool dma_issued = false;
unsigned long timeout;
int ret;
pic32s = spi_master_get_devdata(master);
/* handle transfer specific word size change */
if (transfer->bits_per_word &&
(transfer->bits_per_word != pic32s->bits_per_word)) {
ret = pic32_spi_set_word_size(pic32s, transfer->bits_per_word);
if (ret)
return ret;
pic32s->bits_per_word = transfer->bits_per_word;
}
/* handle transfer specific speed change */
if (transfer->speed_hz && (transfer->speed_hz != pic32s->speed_hz)) {
pic32_spi_set_clk_rate(pic32s, transfer->speed_hz);
pic32s->speed_hz = transfer->speed_hz;
}
reinit_completion(&pic32s->xfer_done);
/* transact by DMA mode */
if (transfer->rx_sg.nents && transfer->tx_sg.nents) {
ret = pic32_spi_dma_transfer(pic32s, transfer);
if (ret) {
dev_err(&spi->dev, "dma submit error\n");
return ret;
}
/* DMA issued */
dma_issued = true;
} else {
/* set current transfer information */
pic32s->tx = (const void *)transfer->tx_buf;
pic32s->rx = (const void *)transfer->rx_buf;
pic32s->tx_end = pic32s->tx + transfer->len;
pic32s->rx_end = pic32s->rx + transfer->len;
pic32s->len = transfer->len;
/* transact by interrupt driven PIO */
enable_irq(pic32s->fault_irq);
enable_irq(pic32s->rx_irq);
enable_irq(pic32s->tx_irq);
}
/* wait for completion */
timeout = wait_for_completion_timeout(&pic32s->xfer_done, 2 * HZ);
if (timeout == 0) {
dev_err(&spi->dev, "wait error/timedout\n");
if (dma_issued) {
dmaengine_terminate_all(master->dma_rx);
dmaengine_terminate_all(master->dma_rx);
}
ret = -ETIMEDOUT;
} else {
ret = 0;
}
return ret;
}
static int pic32_spi_set_wordlen(struct udevice *slave, unsigned int wordlen)
{
struct pic32_spi_priv *priv = dev_get_priv(slave->parent);
return pic32_spi_set_word_size(priv, wordlen);
}
