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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-03-06 14:50:16 -0600 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-03-06 14:50:16 -0600 |
| commit | ae24a21bbd96a7a4a3e82890285255d7e86540f0 (patch) | |
| tree | 2cc7d53c6e0563b9aaaeffb31a8ac5ac9a360034 /drivers/spi/spi-pxa2xx.c | |
| parent | 43c63729c96f06f97367edf680d42d634041fd6a (diff) | |
| parent | f9981d4f50b475d7dbb70f3022b87a3c8bba9fd6 (diff) | |
Merge tag 'spi-fix-v5.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi
Pull spi fixes from Mark Brown:
"A selection of small fixes, mostly for drivers, that have arrived
since the merge window. None of them are earth shattering in
themselves but all useful for affected systems"
* tag 'spi-fix-v5.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
spi: spi_register_controller(): free bus id on error paths
spi: bcm63xx-hsspi: Really keep pll clk enabled
spi: atmel-quadspi: fix possible MMIO window size overrun
spi/zynqmp: remove entry that causes a cs glitch
spi: pxa2xx: Add CS control clock quirk
spi: spidev: Fix CS polarity if GPIO descriptors are used
spi: qup: call spi_qup_pm_resume_runtime before suspending
spi: spi-omap2-mcspi: Support probe deferral for DMA channels
spi: spi-omap2-mcspi: Handle DMA size restriction on AM65x
Diffstat (limited to 'drivers/spi/spi-pxa2xx.c')
| -rw-r--r-- | drivers/spi/spi-pxa2xx.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c index 4c7a71f0fb3e..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) |