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spi: spi-imx: add support for SPI_RX_CPHA_FLIP

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When SPI_RX_CPHA_FLIP is set, flip CPHA on Rx only transfers. This is
useful to access devices that use inverted CPHA for MISO vs MOSI
signals.

Only support the mx51/mx53 variants for now.

Tested on i.MX6ULL based system.

Signed-off-by: Baruch Siach <baruch.siach@siklu.com>
Link: https://lore.kernel.org/r/e11b4446afe9a46a282dd923d22c27d03fae15f8.1649702729.git.baruch@tkos.co.il
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Baruch Siach 2022-04-11 21:45:29 +03:00 committed by Mark Brown
parent 178d0cbbfe
commit 79422ed9bd
No known key found for this signature in database
GPG key ID: 24D68B725D5487D0
1 changed files with 27 additions and 5 deletions
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32
drivers/spi/spi-imx.c
View file

@ -108,6 +108,7 @@ struct spi_imx_data {
const void *tx_buf;
unsigned int txfifo; /* number of words pushed in tx FIFO */
unsigned int dynamic_burst;
bool rx_only;
/* Slave mode */
bool slave_mode;
@ -554,11 +555,6 @@ static int mx51_ecspi_prepare_message(struct spi_imx_data *spi_imx,
else
cfg |= MX51_ECSPI_CONFIG_SBBCTRL(spi->chip_select);
if (spi->mode & SPI_CPHA)
cfg |= MX51_ECSPI_CONFIG_SCLKPHA(spi->chip_select);
else
cfg &= ~MX51_ECSPI_CONFIG_SCLKPHA(spi->chip_select);
if (spi->mode & SPI_CPOL) {
cfg |= MX51_ECSPI_CONFIG_SCLKPOL(spi->chip_select);
cfg |= MX51_ECSPI_CONFIG_SCLKCTL(spi->chip_select);
@ -606,6 +602,24 @@ static int mx51_ecspi_prepare_message(struct spi_imx_data *spi_imx,
return 0;
}
static void mx51_configure_cpha(struct spi_imx_data *spi_imx,
struct spi_device *spi)
{
bool cpha = (spi->mode & SPI_CPHA);
bool flip_cpha = (spi->mode & SPI_RX_CPHA_FLIP) && spi_imx->rx_only;
u32 cfg = readl(spi_imx->base + MX51_ECSPI_CONFIG);
/* Flip cpha logical value iff flip_cpha */
cpha ^= flip_cpha;
if (cpha)
cfg |= MX51_ECSPI_CONFIG_SCLKPHA(spi->chip_select);
else
cfg &= ~MX51_ECSPI_CONFIG_SCLKPHA(spi->chip_select);
writel(cfg, spi_imx->base + MX51_ECSPI_CONFIG);
}
static int mx51_ecspi_prepare_transfer(struct spi_imx_data *spi_imx,
struct spi_device *spi)
{
@ -627,6 +641,8 @@ static int mx51_ecspi_prepare_transfer(struct spi_imx_data *spi_imx,
ctrl |= mx51_ecspi_clkdiv(spi_imx, spi_imx->spi_bus_clk, &clk);
spi_imx->spi_bus_clk = clk;
mx51_configure_cpha(spi_imx, spi);
/*
* ERR009165: work in XHC mode instead of SMC as PIO on the chips
* before i.mx6ul.
@ -1251,6 +1267,9 @@ static int spi_imx_setupxfer(struct spi_device *spi,
else
spi_imx->usedma = false;
spi_imx->rx_only = ((t->tx_buf == NULL)
|| (t->tx_buf == spi->controller->dummy_tx));
if (is_imx53_ecspi(spi_imx) && spi_imx->slave_mode) {
spi_imx->rx = mx53_ecspi_rx_slave;
spi_imx->tx = mx53_ecspi_tx_slave;
@ -1655,6 +1674,9 @@ static int spi_imx_probe(struct platform_device *pdev)
is_imx53_ecspi(spi_imx))
spi_imx->bitbang.master->mode_bits |= SPI_LOOP | SPI_READY;
if (is_imx51_ecspi(spi_imx) || is_imx53_ecspi(spi_imx))
spi_imx->bitbang.master->mode_bits |= SPI_RX_CPHA_FLIP;
if (is_imx51_ecspi(spi_imx) &&
device_property_read_u32(&pdev->dev, "cs-gpios", NULL))
/*