diff options
Diffstat (limited to 'drivers/spi/spi-pxa2xx.c')
| -rw-r--r-- | drivers/spi/spi-pxa2xx.c | 56 |
1 files changed, 40 insertions, 16 deletions
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c index 4c7a71f0fb3e..73d2a65d0b6e 100644 --- a/drivers/spi/spi-pxa2xx.c +++ b/drivers/spi/spi-pxa2xx.c @@ -70,6 +70,10 @@ MODULE_ALIAS("platform:pxa2xx-spi"); #define LPSS_CAPS_CS_EN_SHIFT 9 #define LPSS_CAPS_CS_EN_MASK (0xf << LPSS_CAPS_CS_EN_SHIFT) +#define LPSS_PRIV_CLOCK_GATE 0x38 +#define LPSS_PRIV_CLOCK_GATE_CLK_CTL_MASK 0x3 +#define LPSS_PRIV_CLOCK_GATE_CLK_CTL_FORCE_ON 0x3 + struct lpss_config { /* LPSS offset from drv_data->ioaddr */ unsigned offset; @@ -86,6 +90,8 @@ struct lpss_config { unsigned cs_sel_shift; unsigned cs_sel_mask; unsigned cs_num; + /* Quirks */ + unsigned cs_clk_stays_gated : 1; }; /* Keep these sorted with enum pxa_ssp_type */ @@ -156,6 +162,7 @@ static const struct lpss_config lpss_platforms[] = { .tx_threshold_hi = 56, .cs_sel_shift = 8, .cs_sel_mask = 3 << 8, + .cs_clk_stays_gated = true, }, }; @@ -185,6 +192,11 @@ static bool is_quark_x1000_ssp(const struct driver_data *drv_data) return drv_data->ssp_type == QUARK_X1000_SSP; } +static bool is_mmp2_ssp(const struct driver_data *drv_data) +{ + return drv_data->ssp_type == MMP2_SSP; +} + static u32 pxa2xx_spi_get_ssrc1_change_mask(const struct driver_data *drv_data) { switch (drv_data->ssp_type) { @@ -383,6 +395,22 @@ static void lpss_ssp_cs_control(struct spi_device *spi, bool enable) else value |= LPSS_CS_CONTROL_CS_HIGH; __lpss_ssp_write_priv(drv_data, config->reg_cs_ctrl, value); + if (config->cs_clk_stays_gated) { + u32 clkgate; + + /* + * Changing CS alone when dynamic clock gating is on won't + * actually flip CS at that time. This ruins SPI transfers + * that specify delays, or have no data. Toggle the clock mode + * to force on briefly to poke the CS pin to move. + */ + clkgate = __lpss_ssp_read_priv(drv_data, LPSS_PRIV_CLOCK_GATE); + value = (clkgate & ~LPSS_PRIV_CLOCK_GATE_CLK_CTL_MASK) | + LPSS_PRIV_CLOCK_GATE_CLK_CTL_FORCE_ON; + + __lpss_ssp_write_priv(drv_data, LPSS_PRIV_CLOCK_GATE, value); + __lpss_ssp_write_priv(drv_data, LPSS_PRIV_CLOCK_GATE, clkgate); + } } static void cs_assert(struct spi_device *spi) @@ -463,8 +491,8 @@ int pxa2xx_spi_flush(struct driver_data *drv_data) static void pxa2xx_spi_off(struct driver_data *drv_data) { - /* On MMP, disabling SSE seems to corrupt the rx fifo */ - if (drv_data->ssp_type == MMP2_SSP) + /* On MMP, disabling SSE seems to corrupt the Rx FIFO */ + if (is_mmp2_ssp(drv_data)) return; pxa2xx_spi_write(drv_data, SSCR0, @@ -1070,7 +1098,7 @@ static int pxa2xx_spi_transfer_one(struct spi_controller *controller, || (pxa2xx_spi_read(drv_data, SSCR1) & change_mask) != (cr1 & change_mask)) { /* stop the SSP, and update the other bits */ - if (drv_data->ssp_type != MMP2_SSP) + if (!is_mmp2_ssp(drv_data)) pxa2xx_spi_write(drv_data, SSCR0, cr0 & ~SSCR0_SSE); if (!pxa25x_ssp_comp(drv_data)) pxa2xx_spi_write(drv_data, SSTO, chip->timeout); @@ -1084,7 +1112,7 @@ static int pxa2xx_spi_transfer_one(struct spi_controller *controller, pxa2xx_spi_write(drv_data, SSTO, chip->timeout); } - if (drv_data->ssp_type == MMP2_SSP) { + if (is_mmp2_ssp(drv_data)) { u8 tx_level = (pxa2xx_spi_read(drv_data, SSSR) & SSSR_TFL_MASK) >> 8; @@ -1548,18 +1576,18 @@ pxa2xx_spi_init_pdata(struct platform_device *pdev) else if (pcidev_id) type = (enum pxa_ssp_type)pcidev_id->driver_data; else - return NULL; + return ERR_PTR(-EINVAL); pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); if (!pdata) - return NULL; + return ERR_PTR(-ENOMEM); ssp = &pdata->ssp; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); ssp->mmio_base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(ssp->mmio_base)) - return NULL; + return ERR_CAST(ssp->mmio_base); ssp->phys_base = res->start; @@ -1573,11 +1601,11 @@ pxa2xx_spi_init_pdata(struct platform_device *pdev) ssp->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(ssp->clk)) - return NULL; + return ERR_CAST(ssp->clk); ssp->irq = platform_get_irq(pdev, 0); if (ssp->irq < 0) - return NULL; + return ERR_PTR(ssp->irq); ssp->type = type; ssp->dev = &pdev->dev; @@ -1634,9 +1662,9 @@ static int pxa2xx_spi_probe(struct platform_device *pdev) platform_info = dev_get_platdata(dev); if (!platform_info) { platform_info = pxa2xx_spi_init_pdata(pdev); - if (!platform_info) { + if (IS_ERR(platform_info)) { dev_err(&pdev->dev, "missing platform data\n"); - return -ENODEV; + return PTR_ERR(platform_info); } } @@ -1884,11 +1912,7 @@ out_error_controller_alloc: static int pxa2xx_spi_remove(struct platform_device *pdev) { struct driver_data *drv_data = platform_get_drvdata(pdev); - struct ssp_device *ssp; - - if (!drv_data) - return 0; - ssp = drv_data->ssp; + struct ssp_device *ssp = drv_data->ssp; pm_runtime_get_sync(&pdev->dev); |