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SubjectRe: [PATCH V11 5/5] i2c: tegra: add i2c interface timing support
From
Date
05.02.2019 11:56, Sowjanya Komatineni пишет:
> This patch adds I2C interface timing registers support for
> proper bus rate configuration along with meeting the i2c spec
> setup and hold times based on the tuning performed on Tegra210,
> Tegra186 and Tegra194 platforms.
>
> I2C_INTERFACE_TIMING_0 register contains TLOW and THIGH field
> and Tegra I2C controller design uses them as a part of internal
> clock divisor.
>
> I2C_INTERFACE_TIMING_1 register contains the setup and hold times
> for start and stop conditions.
>
> Acked-by: Thierry Reding <treding@nvidia.com>
> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
> ---
> [V9/V10/V11] : Same as V8
> [V8] : Updated to handle timing implementation within tegra_i2c_init directly
> [V7] : Minor updates to timing implementation
> [V5/V6] : Added this Interface timing patch in V5 of the patch series.
>
> drivers/i2c/busses/i2c-tegra.c | 189 ++++++++++++++++++++++++++++++++++-------
> 1 file changed, 160 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
> index f7584f0ea7da..841cad6ccb57 100644
> --- a/drivers/i2c/busses/i2c-tegra.c
> +++ b/drivers/i2c/busses/i2c-tegra.c
> @@ -129,6 +129,15 @@
> #define I2C_MST_FIFO_STATUS_TX_MASK 0xff0000
> #define I2C_MST_FIFO_STATUS_TX_SHIFT 16
>
> +#define I2C_INTERFACE_TIMING_0 0x94
> +#define I2C_THIGH_SHIFT 8
> +#define I2C_INTERFACE_TIMING_1 0x98
> +
> +#define I2C_STANDARD_MODE 100000
> +#define I2C_FAST_MODE 400000
> +#define I2C_FAST_PLUS_MODE 1000000
> +#define I2C_HS_MODE 3500000
> +
> /* Packet header size in bytes */
> #define I2C_PACKET_HEADER_SIZE 12
>
> @@ -166,7 +175,10 @@ enum msg_end_type {
> * @has_config_load_reg: Has the config load register to load the new
> * configuration.
> * @clk_divisor_hs_mode: Clock divisor in HS mode.
> - * @clk_divisor_std_fast_mode: Clock divisor in standard/fast mode. It is
> + * @clk_divisor_std_mode: Clock divisor in standard mode. It is
> + * applicable if there is no fast clock source i.e. single clock
> + * source.
> + * @clk_divisor_fast_mode: Clock divisor in fast mode. It is
> * applicable if there is no fast clock source i.e. single clock
> * source.
> * @clk_divisor_fast_plus_mode: Clock divisor in fast mode plus. It is
> @@ -184,6 +196,16 @@ enum msg_end_type {
> * @supports_bus_clear: Bus Clear support to recover from bus hang during
> * SDA stuck low from device for some unknown reasons.
> * @has_apb_dma: Support of APBDMA on corresponding Tegra chip.
> + * @tlow_std_mode: Low period of the clock in standard mode.
> + * @thigh_std_mode: High period of the clock in standard mode.
> + * @tlow_fast_fastplus_mode: Low period of the clock in fast/fast-plus modes.
> + * @thigh_fast_fastplus_mode: High period of the clock in fast/fast-plus modes.
> + * @setup_hold_time_std_mode: Setup and hold time for start and stop conditions
> + * in standard mode.
> + * @setup_hold_time_fast_fast_plus_mode: Setup and hold time for start and stop
> + * conditions in fast/fast-plus modes.
> + * @setup_hold_time_hs_mode: Setup and hold time for start and stop conditions
> + * in HS mode.
> */
> struct tegra_i2c_hw_feature {
> bool has_continue_xfer_support;
> @@ -191,7 +213,8 @@ struct tegra_i2c_hw_feature {
> bool has_single_clk_source;
> bool has_config_load_reg;
> int clk_divisor_hs_mode;
> - int clk_divisor_std_fast_mode;
> + int clk_divisor_std_mode;
> + int clk_divisor_fast_mode;
> u16 clk_divisor_fast_plus_mode;
> bool has_multi_master_mode;
> bool has_slcg_override_reg;
> @@ -199,6 +222,13 @@ struct tegra_i2c_hw_feature {
> const struct i2c_adapter_quirks *quirks;
> bool supports_bus_clear;
> bool has_apb_dma;
> + u8 tlow_std_mode;
> + u8 thigh_std_mode;
> + u8 tlow_fast_fastplus_mode;
> + u8 thigh_fast_fastplus_mode;
> + u32 setup_hold_time_std_mode;
> + u32 setup_hold_time_fast_fast_plus_mode;
> + u32 setup_hold_time_hs_mode;
> };
>
> /**
> @@ -666,11 +696,13 @@ static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev)
> return 0;
> }
>
> -static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
> +static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev, bool clk_reinit)
> {
> u32 val;
> int err;
> - u32 clk_divisor;
> + u32 clk_divisor, clk_multiplier;
> + u32 tsu_thd = 0;
> + u8 tlow, thigh;
>
> err = pm_runtime_get_sync(i2c_dev->dev);
> if (err < 0) {
> @@ -700,6 +732,36 @@ static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
> I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT;
> i2c_writel(i2c_dev, clk_divisor, I2C_CLK_DIVISOR);
>
> + if ((i2c_dev->bus_clk_rate > I2C_STANDARD_MODE) &&
> + (i2c_dev->bus_clk_rate <= I2C_FAST_PLUS_MODE)) {

CHECK: Unnecessary parentheses around 'i2c_dev->bus_clk_rate > I2C_STANDARD_MODE'
#1282: FILE: drivers/i2c/busses/i2c-tegra.c:735:
+ if ((i2c_dev->bus_clk_rate > I2C_STANDARD_MODE) &&
+ (i2c_dev->bus_clk_rate <= I2C_FAST_PLUS_MODE)) {

CHECK: Unnecessary parentheses around 'i2c_dev->bus_clk_rate <= I2C_FAST_PLUS_MODE'
#1282: FILE: drivers/i2c/busses/i2c-tegra.c:735:
+ if ((i2c_dev->bus_clk_rate > I2C_STANDARD_MODE) &&
+ (i2c_dev->bus_clk_rate <= I2C_FAST_PLUS_MODE)) {


> + tlow = i2c_dev->hw->tlow_fast_fastplus_mode;
> + thigh = i2c_dev->hw->thigh_fast_fastplus_mode;
> + tsu_thd = i2c_dev->hw->setup_hold_time_fast_fast_plus_mode;
> + } else {
> + tlow = i2c_dev->hw->tlow_std_mode;
> + thigh = i2c_dev->hw->thigh_std_mode;
> + tsu_thd = i2c_dev->hw->setup_hold_time_std_mode;
> + }
> +
> + val = (thigh << I2C_THIGH_SHIFT) | tlow;
> + if (val)
> + i2c_writel(i2c_dev, val, I2C_INTERFACE_TIMING_0);
> +
> + if (tsu_thd)
> + i2c_writel(i2c_dev, tsu_thd, I2C_INTERFACE_TIMING_1);
> +
> + if (!clk_reinit) {
> + clk_multiplier = (tlow + thigh + 2);
> + clk_multiplier *= (i2c_dev->clk_divisor_non_hs_mode + 1);
> + err = clk_set_rate(i2c_dev->div_clk,
> + i2c_dev->bus_clk_rate * clk_multiplier);
> + if (err) {
> + dev_err(i2c_dev->dev,
> + "failed changing clock rate: %d\n", err);
> + goto err;
> + }
> + }
> +
> if (!i2c_dev->is_dvc) {
> u32 sl_cfg = i2c_readl(i2c_dev, I2C_SL_CNFG);
>
> @@ -1106,7 +1168,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
> dmaengine_terminate_sync(i2c_dev->msg_read ?
> i2c_dev->rx_dma_chan :
> i2c_dev->tx_dma_chan);
> - tegra_i2c_init(i2c_dev);
> + tegra_i2c_init(i2c_dev, true);
> return -ETIMEDOUT;
> }
>
> @@ -1133,7 +1195,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
> if (time_left == 0) {
> dev_err(i2c_dev->dev, "i2c transfer timed out\n");
>
> - tegra_i2c_init(i2c_dev);
> + tegra_i2c_init(i2c_dev, true);
> return -ETIMEDOUT;
> }
>
> @@ -1145,7 +1207,7 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
> if (likely(i2c_dev->msg_err == I2C_ERR_NONE))
> return 0;
>
> - tegra_i2c_init(i2c_dev);
> + tegra_i2c_init(i2c_dev, true);
> /* start recovery upon arbitration loss in single master mode */
> if (i2c_dev->msg_err == I2C_ERR_ARBITRATION_LOST) {
> if (!i2c_dev->is_multimaster_mode)
> @@ -1240,7 +1302,8 @@ static const struct tegra_i2c_hw_feature tegra20_i2c_hw = {
> .has_per_pkt_xfer_complete_irq = false,
> .has_single_clk_source = false,
> .clk_divisor_hs_mode = 3,
> - .clk_divisor_std_fast_mode = 0,
> + .clk_divisor_std_mode = 0,
> + .clk_divisor_fast_mode = 0,
> .clk_divisor_fast_plus_mode = 0,
> .has_config_load_reg = false,
> .has_multi_master_mode = false,
> @@ -1249,6 +1312,13 @@ static const struct tegra_i2c_hw_feature tegra20_i2c_hw = {
> .quirks = &tegra_i2c_quirks,
> .supports_bus_clear = false,
> .has_apb_dma = true,
> + .tlow_std_mode = 0x4,
> + .thigh_std_mode = 0x2,
> + .tlow_fast_fastplus_mode = 0x4,
> + .thigh_fast_fastplus_mode = 0x2,
> + .setup_hold_time_std_mode = 0x0,
> + .setup_hold_time_fast_fast_plus_mode = 0x0,
> + .setup_hold_time_hs_mode = 0x0,
> };
>
> static const struct tegra_i2c_hw_feature tegra30_i2c_hw = {
> @@ -1256,7 +1326,8 @@ static const struct tegra_i2c_hw_feature tegra30_i2c_hw = {
> .has_per_pkt_xfer_complete_irq = false,
> .has_single_clk_source = false,
> .clk_divisor_hs_mode = 3,
> - .clk_divisor_std_fast_mode = 0,
> + .clk_divisor_std_mode = 0,
> + .clk_divisor_fast_mode = 0,
> .clk_divisor_fast_plus_mode = 0,
> .has_config_load_reg = false,
> .has_multi_master_mode = false,
> @@ -1265,6 +1336,13 @@ static const struct tegra_i2c_hw_feature tegra30_i2c_hw = {
> .quirks = &tegra_i2c_quirks,
> .supports_bus_clear = false,
> .has_apb_dma = true,
> + .tlow_std_mode = 0x4,
> + .thigh_std_mode = 0x2,
> + .tlow_fast_fastplus_mode = 0x4,
> + .thigh_fast_fastplus_mode = 0x2,
> + .setup_hold_time_std_mode = 0x0,
> + .setup_hold_time_fast_fast_plus_mode = 0x0,
> + .setup_hold_time_hs_mode = 0x0,
> };
>
> static const struct tegra_i2c_hw_feature tegra114_i2c_hw = {
> @@ -1272,7 +1350,8 @@ static const struct tegra_i2c_hw_feature tegra114_i2c_hw = {
> .has_per_pkt_xfer_complete_irq = true,
> .has_single_clk_source = true,
> .clk_divisor_hs_mode = 1,
> - .clk_divisor_std_fast_mode = 0x19,
> + .clk_divisor_std_mode = 0x19,
> + .clk_divisor_fast_mode = 0x19,
> .clk_divisor_fast_plus_mode = 0x10,
> .has_config_load_reg = false,
> .has_multi_master_mode = false,
> @@ -1281,6 +1360,13 @@ static const struct tegra_i2c_hw_feature tegra114_i2c_hw = {
> .quirks = &tegra_i2c_quirks,
> .supports_bus_clear = true,
> .has_apb_dma = true,
> + .tlow_std_mode = 0x4,
> + .thigh_std_mode = 0x2,
> + .tlow_fast_fastplus_mode = 0x4,
> + .thigh_fast_fastplus_mode = 0x2,
> + .setup_hold_time_std_mode = 0x0,
> + .setup_hold_time_fast_fast_plus_mode = 0x0,
> + .setup_hold_time_hs_mode = 0x0,
> };
>
> static const struct tegra_i2c_hw_feature tegra124_i2c_hw = {
> @@ -1288,7 +1374,8 @@ static const struct tegra_i2c_hw_feature tegra124_i2c_hw = {
> .has_per_pkt_xfer_complete_irq = true,
> .has_single_clk_source = true,
> .clk_divisor_hs_mode = 1,
> - .clk_divisor_std_fast_mode = 0x19,
> + .clk_divisor_std_mode = 0x19,
> + .clk_divisor_fast_mode = 0x19,
> .clk_divisor_fast_plus_mode = 0x10,
> .has_config_load_reg = true,
> .has_multi_master_mode = false,
> @@ -1297,6 +1384,13 @@ static const struct tegra_i2c_hw_feature tegra124_i2c_hw = {
> .quirks = &tegra_i2c_quirks,
> .supports_bus_clear = true,
> .has_apb_dma = true,
> + .tlow_std_mode = 0x4,
> + .thigh_std_mode = 0x2,
> + .tlow_fast_fastplus_mode = 0x4,
> + .thigh_fast_fastplus_mode = 0x2,
> + .setup_hold_time_std_mode = 0x0,
> + .setup_hold_time_fast_fast_plus_mode = 0x0,
> + .setup_hold_time_hs_mode = 0x0,
> };
>
> static const struct tegra_i2c_hw_feature tegra210_i2c_hw = {
> @@ -1304,7 +1398,8 @@ static const struct tegra_i2c_hw_feature tegra210_i2c_hw = {
> .has_per_pkt_xfer_complete_irq = true,
> .has_single_clk_source = true,
> .clk_divisor_hs_mode = 1,
> - .clk_divisor_std_fast_mode = 0x19,
> + .clk_divisor_std_mode = 0x19,
> + .clk_divisor_fast_mode = 0x19,
> .clk_divisor_fast_plus_mode = 0x10,
> .has_config_load_reg = true,
> .has_multi_master_mode = true,
> @@ -1313,27 +1408,67 @@ static const struct tegra_i2c_hw_feature tegra210_i2c_hw = {
> .quirks = &tegra_i2c_quirks,
> .supports_bus_clear = true,
> .has_apb_dma = true,
> + .tlow_std_mode = 0x4,
> + .thigh_std_mode = 0x2,
> + .tlow_fast_fastplus_mode = 0x4,
> + .thigh_fast_fastplus_mode = 0x2,
> + .setup_hold_time_std_mode = 0,
> + .setup_hold_time_fast_fast_plus_mode = 0,
> + .setup_hold_time_hs_mode = 0,
> };
>
> -static const struct tegra_i2c_hw_feature tegra194_i2c_hw = {
> +static const struct tegra_i2c_hw_feature tegra186_i2c_hw = {
> .has_continue_xfer_support = true,
> .has_per_pkt_xfer_complete_irq = true,
> .has_single_clk_source = true,
> .clk_divisor_hs_mode = 1,
> - .clk_divisor_std_fast_mode = 0x19,
> + .clk_divisor_std_mode = 0x16,
> + .clk_divisor_fast_mode = 0x19,
> .clk_divisor_fast_plus_mode = 0x10,
> .has_config_load_reg = true,
> .has_multi_master_mode = true,
> .has_slcg_override_reg = true,
> .has_mst_fifo = true,
> + .quirks = &tegra_i2c_quirks,
> + .supports_bus_clear = true,
> + .has_apb_dma = false,
> + .tlow_std_mode = 0x4,
> + .thigh_std_mode = 0x3,
> + .tlow_fast_fastplus_mode = 0x4,
> + .thigh_fast_fastplus_mode = 0x2,
> + .setup_hold_time_std_mode = 0,
> + .setup_hold_time_fast_fast_plus_mode = 0,
> + .setup_hold_time_hs_mode = 0,
> +};
> +
> +static const struct tegra_i2c_hw_feature tegra194_i2c_hw = {
> + .has_continue_xfer_support = true,
> + .has_per_pkt_xfer_complete_irq = true,
> + .has_single_clk_source = true,
> + .clk_divisor_hs_mode = 1,
> + .clk_divisor_std_mode = 0x4f,
> + .clk_divisor_fast_mode = 0x3c,
> + .clk_divisor_fast_plus_mode = 0x16,
> + .has_config_load_reg = true,
> + .has_multi_master_mode = true,
> + .has_slcg_override_reg = true,
> + .has_mst_fifo = true,
> .quirks = &tegra194_i2c_quirks,
> .supports_bus_clear = true,
> .has_apb_dma = false,
> + .tlow_std_mode = 0x8,
> + .thigh_std_mode = 0x7,
> + .tlow_fast_fastplus_mode = 0x2,
> + .thigh_fast_fastplus_mode = 0x2,
> + .setup_hold_time_std_mode = 0x08080808,
> + .setup_hold_time_fast_fast_plus_mode = 0x02020202,
> + .setup_hold_time_hs_mode = 0x090909,
> };
>
> /* Match table for of_platform binding */
> static const struct of_device_id tegra_i2c_of_match[] = {
> { .compatible = "nvidia,tegra194-i2c", .data = &tegra194_i2c_hw, },
> + { .compatible = "nvidia,tegra186-i2c", .data = &tegra186_i2c_hw, },
> { .compatible = "nvidia,tegra210-i2c", .data = &tegra210_i2c_hw, },
> { .compatible = "nvidia,tegra124-i2c", .data = &tegra124_i2c_hw, },
> { .compatible = "nvidia,tegra114-i2c", .data = &tegra114_i2c_hw, },
> @@ -1354,7 +1489,6 @@ static int tegra_i2c_probe(struct platform_device *pdev)
> phys_addr_t base_phys;
> int irq;
> int ret = 0;
> - int clk_multiplier = I2C_CLK_MULTIPLIER_STD_FAST_MODE;
>
> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> base_phys = res->start;
> @@ -1425,20 +1559,17 @@ static int tegra_i2c_probe(struct platform_device *pdev)
> }
> }
>
> - i2c_dev->clk_divisor_non_hs_mode =
> - i2c_dev->hw->clk_divisor_std_fast_mode;
> - if (i2c_dev->hw->clk_divisor_fast_plus_mode &&
> - (i2c_dev->bus_clk_rate == 1000000))
> + if ((i2c_dev->bus_clk_rate > I2C_FAST_MODE) &&
> + (i2c_dev->bus_clk_rate <= I2C_FAST_PLUS_MODE))

CHECK: Unnecessary parentheses around 'i2c_dev->bus_clk_rate > I2C_FAST_MODE'
#1534: FILE: drivers/i2c/busses/i2c-tegra.c:1562:
+ if ((i2c_dev->bus_clk_rate > I2C_FAST_MODE) &&
+ (i2c_dev->bus_clk_rate <= I2C_FAST_PLUS_MODE))

CHECK: Unnecessary parentheses around 'i2c_dev->bus_clk_rate <= I2C_FAST_PLUS_MODE'
#1534: FILE: drivers/i2c/busses/i2c-tegra.c:1562:
+ if ((i2c_dev->bus_clk_rate > I2C_FAST_MODE) &&
+ (i2c_dev->bus_clk_rate <= I2C_FAST_PLUS_MODE))

[snip]

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