[RFC PATCH V2 06/12] i2c: tegra: split clock initialization code

Krishna Yarlagadda
2024-07-01T15:13:34Z

Add new methods for setting clock parameters and setting
clock divisor.

Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
---
drivers/i2c/busses/i2c-tegra.c | 127 ++++++++++++++++++++-------------
1 file changed, 77 insertions(+), 50 deletions(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 85b31edc558d..b3dc2603db35 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -604,12 +604,83 @@ static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev)
return 0;
}

+static void tegra_i2c_set_clk_params(struct tegra_i2c_dev *i2c_dev)
+{
+ u32 val, clk_divisor, tsu_thd, tlow, thigh, non_hs_mode;
+
+ switch (i2c_dev->timings.bus_freq_hz) {
+ case I2C_MAX_STANDARD_MODE_FREQ + 1 ... I2C_MAX_FAST_MODE_PLUS_FREQ:
+ default:
+ 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;
+
+ if (i2c_dev->timings.bus_freq_hz > I2C_MAX_FAST_MODE_FREQ)
+ non_hs_mode = i2c_dev->hw->clk_divisor_fast_plus_mode;
+ else
+ non_hs_mode = i2c_dev->hw->clk_divisor_fast_mode;
+ break;
+
+ case 0 ... I2C_MAX_STANDARD_MODE_FREQ:
+ tlow = i2c_dev->hw->tlow_std_mode;
+ thigh = i2c_dev->hw->thigh_std_mode;
+ tsu_thd = i2c_dev->hw->setup_hold_time_std_mode;
+ non_hs_mode = i2c_dev->hw->clk_divisor_std_mode;
+ break;
+ }
+
+ /* make sure clock divisor programmed correctly */
+ clk_divisor = FIELD_PREP(I2C_CLK_DIVISOR_HSMODE,
+ i2c_dev->hw->clk_divisor_hs_mode) |
+ FIELD_PREP(I2C_CLK_DIVISOR_STD_FAST_MODE, non_hs_mode);
+ i2c_writel(i2c_dev, clk_divisor, I2C_CLK_DIVISOR);
+
+ if (i2c_dev->hw->has_interface_timing_reg) {
+ val = FIELD_PREP(I2C_INTERFACE_TIMING_THIGH, thigh) |
+ FIELD_PREP(I2C_INTERFACE_TIMING_TLOW, tlow);
+ i2c_writel(i2c_dev, val, I2C_INTERFACE_TIMING_0);
+ }
+
+ /*
+ * Configure setup and hold times only when tsu_thd is non-zero.
+ * Otherwise, preserve the chip default values.
+ */
+ if (i2c_dev->hw->has_interface_timing_reg && tsu_thd)
+ i2c_writel(i2c_dev, tsu_thd, I2C_INTERFACE_TIMING_1);
+}
+
+static int tegra_i2c_set_div_clk(struct tegra_i2c_dev *i2c_dev)
+{
+ u32 clk_multiplier, tlow, thigh, non_hs_mode;
+ u32 timing, clk_divisor;
+ int err;
+
+ timing = i2c_readl(i2c_dev, I2C_INTERFACE_TIMING_0);
+
+ tlow = FIELD_GET(I2C_INTERFACE_TIMING_TLOW, timing);
+ thigh = FIELD_GET(I2C_INTERFACE_TIMING_THIGH, timing);
+
+ clk_divisor = i2c_readl(i2c_dev, I2C_CLK_DIVISOR);
+
+ non_hs_mode = FIELD_GET(I2C_CLK_DIVISOR_STD_FAST_MODE, clk_divisor);
+
+ clk_multiplier = (thigh + tlow + 2) * (non_hs_mode + 1);
+
+ err = clk_set_rate(i2c_dev->div_clk,
+ i2c_dev->timings.bus_freq_hz * clk_multiplier);
+ if (err) {
+ dev_err(i2c_dev->dev, "failed to set div_clk rate: %d\n", err);
+ return err;
+ }
+
+ return 0;
+}
+
static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
{
- u32 val, clk_divisor, clk_multiplier, tsu_thd, tlow, thigh, non_hs_mode;
+ u32 val;
+ int err;
acpi_handle handle = ACPI_HANDLE(i2c_dev->dev);
- struct i2c_timings *t = &i2c_dev->timings;
- int err;

/*
* The reset shouldn't ever fail in practice. The failure will be a
@@ -641,54 +712,10 @@ static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
if (IS_VI(i2c_dev))
tegra_i2c_vi_init(i2c_dev);

- switch (t->bus_freq_hz) {
- case I2C_MAX_STANDARD_MODE_FREQ + 1 ... I2C_MAX_FAST_MODE_PLUS_FREQ:
- default:
- 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;
-
- if (t->bus_freq_hz > I2C_MAX_FAST_MODE_FREQ)
- non_hs_mode = i2c_dev->hw->clk_divisor_fast_plus_mode;
- else
- non_hs_mode = i2c_dev->hw->clk_divisor_fast_mode;
- break;
-
- case 0 ... I2C_MAX_STANDARD_MODE_FREQ:
- tlow = i2c_dev->hw->tlow_std_mode;
- thigh = i2c_dev->hw->thigh_std_mode;
- tsu_thd = i2c_dev->hw->setup_hold_time_std_mode;
- non_hs_mode = i2c_dev->hw->clk_divisor_std_mode;
- break;
- }
-
- /* make sure clock divisor programmed correctly */
- clk_divisor = FIELD_PREP(I2C_CLK_DIVISOR_HSMODE,
- i2c_dev->hw->clk_divisor_hs_mode) |
- FIELD_PREP(I2C_CLK_DIVISOR_STD_FAST_MODE, non_hs_mode);
- i2c_writel(i2c_dev, clk_divisor, I2C_CLK_DIVISOR);
-
- if (i2c_dev->hw->has_interface_timing_reg) {
- val = FIELD_PREP(I2C_INTERFACE_TIMING_THIGH, thigh) |
- FIELD_PREP(I2C_INTERFACE_TIMING_TLOW, tlow);
- i2c_writel(i2c_dev, val, I2C_INTERFACE_TIMING_0);
- }
-
- /*
- * Configure setup and hold times only when tsu_thd is non-zero.
- * Otherwise, preserve the chip default values.
- */
- if (i2c_dev->hw->has_interface_timing_reg && tsu_thd)
- i2c_writel(i2c_dev, tsu_thd, I2C_INTERFACE_TIMING_1);
-
- clk_multiplier = (tlow + thigh + 2) * (non_hs_mode + 1);
-
- err = clk_set_rate(i2c_dev->div_clk,
- t->bus_freq_hz * clk_multiplier);
- if (err) {
- dev_err(i2c_dev->dev, "failed to set div-clk rate: %d\n", err);
+ tegra_i2c_set_clk_params(i2c_dev);
+ err = tegra_i2c_set_div_clk(i2c_dev);
+ if (err)
return err;
- }

if (!IS_DVC(i2c_dev) && !IS_VI(i2c_dev)) {
u32 sl_cfg = i2c_readl(i2c_dev, I2C_SL_CNFG);
--
2.43.2