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authorSowjanya Komatineni <skomatineni@nvidia.com>2019-05-13 22:03:55 -0700
committerMark Brown <broonie@kernel.org>2019-05-15 12:17:56 +0100
commit318dacbd049b447a5b45290b39f1c889b9cbde4d (patch)
treed9ae6433e75e125f0de28f19a850304064adfc95 /drivers/spi
parent9b76ef39b7fbc2ddb0869725f9745a402d93cce5 (diff)
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spi: tegra114: add support for TX and RX trimmers
Tegra SPI master controller has programmable trimmers to adjust the data with respect to the clock. These trimmers are programmed in TX_CLK_TAP_DELAY and RX_CLK_TAP_DELAY fields of COMMAND2 register. SPI TX trimmer is to adjust the outgoing data with respect to the outgoing clock and SPI RX trimmer is to adjust the loopback clock with respect to the incoming data from the slave device. These trimmers vary based on trace lengths of the platform design for each of the slaves on the SPI bus and optimal value programmed is from the platform validation across PVT. This patch adds support for configuring TX and RX clock delay trimmers through the device tree properties. Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi-tegra114.c67
1 files changed, 65 insertions, 2 deletions
diff --git a/drivers/spi/spi-tegra114.c b/drivers/spi/spi-tegra114.c
index e59ff7c1cee6..253a7f182fc9 100644
--- a/drivers/spi/spi-tegra114.c
+++ b/drivers/spi/spi-tegra114.c
@@ -169,6 +169,11 @@ struct tegra_spi_soc_data {
bool has_intr_mask_reg;
};
+struct tegra_spi_client_data {
+ int tx_clk_tap_delay;
+ int rx_clk_tap_delay;
+};
+
struct tegra_spi_data {
struct device *dev;
struct spi_master *master;
@@ -208,8 +213,10 @@ struct tegra_spi_data {
u32 command1_reg;
u32 dma_control_reg;
u32 def_command1_reg;
+ u32 def_command2_reg;
u32 spi_cs_timing1;
u32 spi_cs_timing2;
+ u8 last_used_cs;
struct completion xfer_completion;
struct spi_transfer *curr_xfer;
@@ -770,10 +777,12 @@ static u32 tegra_spi_setup_transfer_one(struct spi_device *spi,
bool is_single_xfer)
{
struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
+ struct tegra_spi_client_data *cdata = spi->controller_data;
u32 speed = t->speed_hz;
u8 bits_per_word = t->bits_per_word;
- u32 command1;
+ u32 command1, command2;
int req_mode;
+ u32 tx_tap = 0, rx_tap = 0;
if (speed != tspi->cur_speed) {
clk_set_rate(tspi->clk, speed);
@@ -836,7 +845,18 @@ static u32 tegra_spi_setup_transfer_one(struct spi_device *spi,
command1 &= ~SPI_CS_SW_VAL;
}
- tegra_spi_writel(tspi, 0, SPI_COMMAND2);
+ if (tspi->last_used_cs != spi->chip_select) {
+ if (cdata && cdata->tx_clk_tap_delay)
+ tx_tap = cdata->tx_clk_tap_delay;
+ if (cdata && cdata->rx_clk_tap_delay)
+ rx_tap = cdata->rx_clk_tap_delay;
+ command2 = SPI_TX_TAP_DELAY(tx_tap) |
+ SPI_RX_TAP_DELAY(rx_tap);
+ if (command2 != tspi->def_command2_reg)
+ tegra_spi_writel(tspi, command2, SPI_COMMAND2);
+ tspi->last_used_cs = spi->chip_select;
+ }
+
} else {
command1 = tspi->command1_reg;
command1 &= ~SPI_BIT_LENGTH(~0);
@@ -892,9 +912,42 @@ static int tegra_spi_start_transfer_one(struct spi_device *spi,
return ret;
}
+static struct tegra_spi_client_data
+ *tegra_spi_parse_cdata_dt(struct spi_device *spi)
+{
+ struct tegra_spi_client_data *cdata;
+ struct device_node *slave_np;
+
+ slave_np = spi->dev.of_node;
+ if (!slave_np) {
+ dev_dbg(&spi->dev, "device node not found\n");
+ return NULL;
+ }
+
+ cdata = kzalloc(sizeof(*cdata), GFP_KERNEL);
+ if (!cdata)
+ return NULL;
+
+ of_property_read_u32(slave_np, "nvidia,tx-clk-tap-delay",
+ &cdata->tx_clk_tap_delay);
+ of_property_read_u32(slave_np, "nvidia,rx-clk-tap-delay",
+ &cdata->rx_clk_tap_delay);
+ return cdata;
+}
+
+static void tegra_spi_cleanup(struct spi_device *spi)
+{
+ struct tegra_spi_client_data *cdata = spi->controller_data;
+
+ spi->controller_data = NULL;
+ if (spi->dev.of_node)
+ kfree(cdata);
+}
+
static int tegra_spi_setup(struct spi_device *spi)
{
struct tegra_spi_data *tspi = spi_master_get_devdata(spi->master);
+ struct tegra_spi_client_data *cdata = spi->controller_data;
u32 val;
unsigned long flags;
int ret;
@@ -905,6 +958,11 @@ static int tegra_spi_setup(struct spi_device *spi)
spi->mode & SPI_CPHA ? "" : "~",
spi->max_speed_hz);
+ if (!cdata) {
+ cdata = tegra_spi_parse_cdata_dt(spi);
+ spi->controller_data = cdata;
+ }
+
ret = pm_runtime_get_sync(tspi->dev);
if (ret < 0) {
dev_err(tspi->dev, "pm runtime failed, e = %d\n", ret);
@@ -1034,6 +1092,7 @@ static int tegra_spi_transfer_one_message(struct spi_master *master,
reset_control_assert(tspi->rst);
udelay(2);
reset_control_deassert(tspi->rst);
+ tspi->last_used_cs = master->num_chipselect + 1;
goto complete_xfer;
}
@@ -1351,6 +1410,8 @@ static int tegra_spi_probe(struct platform_device *pdev)
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);
+ tspi->def_command2_reg = tegra_spi_readl(tspi, SPI_COMMAND2);
+ tspi->last_used_cs = master->num_chipselect + 1;
pm_runtime_put(&pdev->dev);
ret = request_threaded_irq(tspi->irq, tegra_spi_isr,
tegra_spi_isr_thread, IRQF_ONESHOT,
@@ -1423,6 +1484,8 @@ static int tegra_spi_resume(struct device *dev)
return ret;
}
tegra_spi_writel(tspi, tspi->command1_reg, SPI_COMMAND1);
+ tegra_spi_writel(tspi, tspi->def_command2_reg, SPI_COMMAND2);
+ tspi->last_used_cs = master->num_chipselect + 1;
pm_runtime_put(dev);
return spi_master_resume(master);