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>
This commit is contained in:
Sowjanya Komatineni 2019-05-13 22:03:54 -07:00 committed by Mark Brown
parent 1bf9f3c923
commit 9b76ef39b7
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GPG Key ID: 24D68B725D5487D0

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@ -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,