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spi: imx: mx51-ecspi: Move some initialisation to prepare_message hook. 

The relevant difference between prepare_message and config is that the
former is run before the CS signal is asserted. So the polarity of the
CLK line must be configured in prepare_message as an edge generated by
config might already result in a latch of the MOSI line.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Uwe Kleine-König 2018-11-30 07:47:06 +01:00 committed by Mark Brown
parent e697271c4e
commit 00b80ac935
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 40 additions and 27 deletions
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67
drivers/spi/spi-imx.c
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@ -490,14 +490,9 @@ static void mx51_ecspi_disable(struct spi_imx_data *spi_imx)
static int mx51_ecspi_prepare_message(struct spi_imx_data *spi_imx,
struct spi_message *msg)
{
return 0;
}
static int mx51_ecspi_config(struct spi_device *spi)
{
struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
struct spi_device *spi = msg->spi;
u32 ctrl = MX51_ECSPI_CTRL_ENABLE;
u32 clk = spi_imx->speed_hz, delay, reg;
u32 testreg;
u32 cfg = readl(spi_imx->base + MX51_ECSPI_CONFIG);
/* set Master or Slave mode */
@ -512,19 +507,21 @@ static int mx51_ecspi_config(struct spi_device *spi)
if (spi->mode & SPI_READY)
ctrl |= MX51_ECSPI_CTRL_DRCTL(spi_imx->spi_drctl);
/* set clock speed */
ctrl |= mx51_ecspi_clkdiv(spi_imx, spi_imx->speed_hz, &clk);
spi_imx->spi_bus_clk = clk;
/* set chip select to use */
ctrl |= MX51_ECSPI_CTRL_CS(spi->chip_select);
if (spi_imx->slave_mode && is_imx53_ecspi(spi_imx))
ctrl |= (spi_imx->slave_burst * 8 - 1)
<< MX51_ECSPI_CTRL_BL_OFFSET;
/*
* The ctrl register must be written first, with the EN bit set other
* registers must not be written to.
*/
writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
testreg = readl(spi_imx->base + MX51_ECSPI_TESTREG);
if (spi->mode & SPI_LOOP)
testreg |= MX51_ECSPI_TESTREG_LBC;
else
ctrl |= (spi_imx->bits_per_word - 1)
<< MX51_ECSPI_CTRL_BL_OFFSET;
testreg &= ~MX51_ECSPI_TESTREG_LBC;
writel(testreg, spi_imx->base + MX51_ECSPI_TESTREG);
/*
* eCSPI burst completion by Chip Select signal in Slave mode
@ -548,26 +545,43 @@ static int mx51_ecspi_config(struct spi_device *spi)
cfg &= ~MX51_ECSPI_CONFIG_SCLKPOL(spi->chip_select);
cfg &= ~MX51_ECSPI_CONFIG_SCLKCTL(spi->chip_select);
}
if (spi->mode & SPI_CS_HIGH)
cfg |= MX51_ECSPI_CONFIG_SSBPOL(spi->chip_select);
else
cfg &= ~MX51_ECSPI_CONFIG_SSBPOL(spi->chip_select);
writel(cfg, spi_imx->base + MX51_ECSPI_CONFIG);
return 0;
}
static int mx51_ecspi_config(struct spi_device *spi)
{
struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
u32 ctrl = readl(spi_imx->base + MX51_ECSPI_CTRL);
u32 clk = spi_imx->speed_hz, delay;
/* Clear BL field and set the right value */
ctrl &= ~MX51_ECSPI_CTRL_BL_MASK;
if (spi_imx->slave_mode && is_imx53_ecspi(spi_imx))
ctrl |= (spi_imx->slave_burst * 8 - 1)
<< MX51_ECSPI_CTRL_BL_OFFSET;
else
ctrl |= (spi_imx->bits_per_word - 1)
<< MX51_ECSPI_CTRL_BL_OFFSET;
/* set clock speed */
ctrl &= ~(0xf << MX51_ECSPI_CTRL_POSTDIV_OFFSET |
0xf << MX51_ECSPI_CTRL_PREDIV_OFFSET);
ctrl |= mx51_ecspi_clkdiv(spi_imx, spi_imx->speed_hz, &clk);
spi_imx->spi_bus_clk = clk;
if (spi_imx->usedma)
ctrl |= MX51_ECSPI_CTRL_SMC;
/* CTRL register always go first to bring out controller from reset */
writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
reg = readl(spi_imx->base + MX51_ECSPI_TESTREG);
if (spi->mode & SPI_LOOP)
reg |= MX51_ECSPI_TESTREG_LBC;
else
reg &= ~MX51_ECSPI_TESTREG_LBC;
writel(reg, spi_imx->base + MX51_ECSPI_TESTREG);
writel(cfg, spi_imx->base + MX51_ECSPI_CONFIG);
/*
* Wait until the changes in the configuration register CONFIGREG
* propagate into the hardware. It takes exactly one tick of the
@ -594,7 +608,6 @@ static void mx51_setup_wml(struct spi_imx_data *spi_imx)
* Configure the DMA register: setup the watermark
* and enable DMA request.
*/
writel(MX51_ECSPI_DMA_RX_WML(spi_imx->wml - 1) |
MX51_ECSPI_DMA_TX_WML(spi_imx->wml) |
MX51_ECSPI_DMA_RXT_WML(spi_imx->wml) |