diff options
Diffstat (limited to 'drivers/spi/spi-pxa2xx.c')
| -rw-r--r-- | drivers/spi/spi-pxa2xx.c | 54 |
1 files changed, 43 insertions, 11 deletions
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c index 9071333ebdd8..2e318158fca9 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, }, }; @@ -383,6 +390,22 @@ 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) @@ -461,6 +484,16 @@ int pxa2xx_spi_flush(struct driver_data *drv_data) return limit; } +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) + return; + + pxa2xx_spi_write(drv_data, SSCR0, + pxa2xx_spi_read(drv_data, SSCR0) & ~SSCR0_SSE); +} + static int null_writer(struct driver_data *drv_data) { u8 n_bytes = drv_data->n_bytes; @@ -587,8 +620,7 @@ static void int_error_stop(struct driver_data *drv_data, const char* msg) if (!pxa25x_ssp_comp(drv_data)) pxa2xx_spi_write(drv_data, SSTO, 0); pxa2xx_spi_flush(drv_data); - pxa2xx_spi_write(drv_data, SSCR0, - pxa2xx_spi_read(drv_data, SSCR0) & ~SSCR0_SSE); + pxa2xx_spi_off(drv_data); dev_err(&drv_data->pdev->dev, "%s\n", msg); @@ -686,8 +718,7 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data) static void handle_bad_msg(struct driver_data *drv_data) { - pxa2xx_spi_write(drv_data, SSCR0, - pxa2xx_spi_read(drv_data, SSCR0) & ~SSCR0_SSE); + pxa2xx_spi_off(drv_data); pxa2xx_spi_write(drv_data, SSCR1, pxa2xx_spi_read(drv_data, SSCR1) & ~drv_data->int_cr1); if (!pxa25x_ssp_comp(drv_data)) @@ -1062,7 +1093,8 @@ 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 */ - pxa2xx_spi_write(drv_data, SSCR0, cr0 & ~SSCR0_SSE); + if (drv_data->ssp_type != MMP2_SSP) + pxa2xx_spi_write(drv_data, SSCR0, cr0 & ~SSCR0_SSE); if (!pxa25x_ssp_comp(drv_data)) pxa2xx_spi_write(drv_data, SSTO, chip->timeout); /* first set CR1 without interrupt and service enables */ @@ -1118,8 +1150,7 @@ static int pxa2xx_spi_slave_abort(struct spi_controller *controller) if (!pxa25x_ssp_comp(drv_data)) pxa2xx_spi_write(drv_data, SSTO, 0); pxa2xx_spi_flush(drv_data); - pxa2xx_spi_write(drv_data, SSCR0, - pxa2xx_spi_read(drv_data, SSCR0) & ~SSCR0_SSE); + pxa2xx_spi_off(drv_data); dev_dbg(&drv_data->pdev->dev, "transfer aborted\n"); @@ -1135,8 +1166,7 @@ static void pxa2xx_spi_handle_err(struct spi_controller *controller, struct driver_data *drv_data = spi_controller_get_devdata(controller); /* Disable the SSP */ - pxa2xx_spi_write(drv_data, SSCR0, - pxa2xx_spi_read(drv_data, SSCR0) & ~SSCR0_SSE); + pxa2xx_spi_off(drv_data); /* Clear and disable interrupts and service requests */ write_SSSR_CS(drv_data, drv_data->clear_sr); pxa2xx_spi_write(drv_data, SSCR1, @@ -1161,8 +1191,7 @@ static int pxa2xx_spi_unprepare_transfer(struct spi_controller *controller) struct driver_data *drv_data = spi_controller_get_devdata(controller); /* Disable the SSP now */ - pxa2xx_spi_write(drv_data, SSCR0, - pxa2xx_spi_read(drv_data, SSCR0) & ~SSCR0_SSE); + pxa2xx_spi_off(drv_data); return 0; } @@ -1423,6 +1452,9 @@ static const struct pci_device_id pxa2xx_spi_pci_compound_match[] = { /* KBL-H */ { PCI_VDEVICE(INTEL, 0xa2a9), LPSS_SPT_SSP }, { PCI_VDEVICE(INTEL, 0xa2aa), LPSS_SPT_SSP }, + /* CML-V */ + { PCI_VDEVICE(INTEL, 0xa3a9), LPSS_SPT_SSP }, + { PCI_VDEVICE(INTEL, 0xa3aa), LPSS_SPT_SSP }, /* BXT A-Step */ { PCI_VDEVICE(INTEL, 0x0ac2), LPSS_BXT_SSP }, { PCI_VDEVICE(INTEL, 0x0ac4), LPSS_BXT_SSP }, |