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| author | Sowjanya Komatineni <skomatineni@nvidia.com> | 2019-05-13 22:03:54 -0700 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2019-05-15 12:17:43 +0100 |
| commit | 9b76ef39b7fbc2ddb0869725f9745a402d93cce5 (patch) | |
| tree | f3d1a57126bdae7fbc2a876e2c1e83d34c294a2c /drivers/spi/spi-tegra114.c | |
| parent | 1bf9f3c9232d08651aa6990001e7b042c95303dc (diff) | |
| download | lwn-9b76ef39b7fbc2ddb0869725f9745a402d93cce5.tar.gz lwn-9b76ef39b7fbc2ddb0869725f9745a402d93cce5.zip | |
spi: tegra114: add support for HW CS timing
This patch implements set_cs_timing SPI controller method to allow
SPI client driver to configure device specific SPI CS timings.
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi-tegra114.c')
| -rw-r--r-- | drivers/spi/spi-tegra114.c | 48 |
1 files changed, 46 insertions, 2 deletions
diff --git a/drivers/spi/spi-tegra114.c b/drivers/spi/spi-tegra114.c index 0cb0932d32fd..e59ff7c1cee6 100644 --- a/drivers/spi/spi-tegra114.c +++ b/drivers/spi/spi-tegra114.c @@ -95,8 +95,10 @@ (reg = (((val) & 0x1) << ((cs) * 8 + 5)) | \ ((reg) & ~(1 << ((cs) * 8 + 5)))) #define SPI_SET_CYCLES_BETWEEN_PACKETS(reg, cs, val) \ - (reg = (((val) & 0xF) << ((cs) * 8)) | \ - ((reg) & ~(0xF << ((cs) * 8)))) + (reg = (((val) & 0x1F) << ((cs) * 8)) | \ + ((reg) & ~(0x1F << ((cs) * 8)))) +#define MAX_SETUP_HOLD_CYCLES 16 +#define MAX_INACTIVE_CYCLES 32 #define SPI_TRANS_STATUS 0x010 #define SPI_BLK_CNT(val) (((val) >> 0) & 0xFFFF) @@ -206,6 +208,8 @@ struct tegra_spi_data { u32 command1_reg; u32 dma_control_reg; u32 def_command1_reg; + u32 spi_cs_timing1; + u32 spi_cs_timing2; struct completion xfer_completion; struct spi_transfer *curr_xfer; @@ -723,6 +727,43 @@ static void tegra_spi_deinit_dma_param(struct tegra_spi_data *tspi, dma_release_channel(dma_chan); } +static void tegra_spi_set_hw_cs_timing(struct spi_device *spi, u8 setup_dly, + u8 hold_dly, u8 inactive_dly) +{ + struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master); + u32 setup_hold; + u32 spi_cs_timing; + u32 inactive_cycles; + u8 cs_state; + + setup_dly = min_t(u8, setup_dly, MAX_SETUP_HOLD_CYCLES); + hold_dly = min_t(u8, hold_dly, MAX_SETUP_HOLD_CYCLES); + if (setup_dly && hold_dly) { + setup_hold = SPI_SETUP_HOLD(setup_dly - 1, hold_dly - 1); + spi_cs_timing = SPI_CS_SETUP_HOLD(tspi->spi_cs_timing1, + spi->chip_select, + setup_hold); + if (tspi->spi_cs_timing1 != spi_cs_timing) { + tspi->spi_cs_timing1 = spi_cs_timing; + tegra_spi_writel(tspi, spi_cs_timing, SPI_CS_TIMING1); + } + } + + inactive_cycles = min_t(u8, inactive_dly, MAX_INACTIVE_CYCLES); + if (inactive_cycles) + inactive_cycles--; + cs_state = inactive_cycles ? 0 : 1; + spi_cs_timing = tspi->spi_cs_timing2; + SPI_SET_CS_ACTIVE_BETWEEN_PACKETS(spi_cs_timing, spi->chip_select, + cs_state); + SPI_SET_CYCLES_BETWEEN_PACKETS(spi_cs_timing, spi->chip_select, + inactive_cycles); + if (tspi->spi_cs_timing2 != spi_cs_timing) { + tspi->spi_cs_timing2 = spi_cs_timing; + tegra_spi_writel(tspi, spi_cs_timing, SPI_CS_TIMING2); + } +} + static u32 tegra_spi_setup_transfer_one(struct spi_device *spi, struct spi_transfer *t, bool is_first_of_msg, @@ -1232,6 +1273,7 @@ static int tegra_spi_probe(struct platform_device *pdev) master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32); master->setup = tegra_spi_setup; master->transfer_one_message = tegra_spi_transfer_one_message; + master->set_cs_timing = tegra_spi_set_hw_cs_timing; master->num_chipselect = MAX_CHIP_SELECT; master->auto_runtime_pm = true; bus_num = of_alias_get_id(pdev->dev.of_node, "spi"); @@ -1307,6 +1349,8 @@ static int tegra_spi_probe(struct platform_device *pdev) reset_control_deassert(tspi->rst); tspi->def_command1_reg = SPI_M_S; tegra_spi_writel(tspi, tspi->def_command1_reg, SPI_COMMAND1); + tspi->spi_cs_timing1 = tegra_spi_readl(tspi, SPI_CS_TIMING1); + tspi->spi_cs_timing2 = tegra_spi_readl(tspi, SPI_CS_TIMING2); pm_runtime_put(&pdev->dev); ret = request_threaded_irq(tspi->irq, tegra_spi_isr, tegra_spi_isr_thread, IRQF_ONESHOT, |