ITE: drivers/i2c: Add the property of I2C data hold time

Add a property to adjust the I2C data hold time which will pass
the SI test.

Signed-off-by: Tim Lin <tim2.lin@ite.corp-partner.google.com>

drivers/i2c/i2c_ite_enhance.c

@@ -71,6 +71,7 @@ struct i2c_enhance_config {
 	/* I2C alternate configuration */
 	const struct pinctrl_dev_config *pcfg;
 	uint8_t prescale_scl_low;
+	uint8_t data_hold_time;
 	uint32_t clock_gate_offset;
 	bool target_enable;
 	bool target_pio_mode;
@@ -1145,6 +1146,7 @@ static int i2c_enhance_init(const struct device *dev)
 	struct i2c_enhance_data *data = dev->data;
 	const struct i2c_enhance_config *config = dev->config;
 	uint8_t *base = config->base;
+	uint8_t data_hold_time = config->data_hold_time;
 	uint32_t bitrate_cfg;
 	int error, status;
 
@@ -1196,6 +1198,10 @@ static int i2c_enhance_init(const struct device *dev)
 				(IT8XXX2_SMB_SMB45CHS &= ~GENMASK(6, 4));
 		}
 
+		/* Set I2C data hold time. */
+		IT8XXX2_I2C_DHTR(base) = (IT8XXX2_I2C_DHTR(base) & ~GENMASK(2, 0)) |
+			(data_hold_time - 3);
+
 		/* Set clock frequency for I2C ports */
 		if (config->bitrate == I2C_BITRATE_STANDARD ||
 			config->bitrate == I2C_BITRATE_FAST ||
@@ -1453,6 +1459,7 @@ BUILD_ASSERT(IS_ENABLED(CONFIG_I2C_TARGET_BUFFER_MODE),
 		.scl_gpios = GPIO_DT_SPEC_INST_GET(inst, scl_gpios),            \
 		.sda_gpios = GPIO_DT_SPEC_INST_GET(inst, sda_gpios),            \
 		.prescale_scl_low = DT_INST_PROP_OR(inst, prescale_scl_low, 0), \
+		.data_hold_time = DT_INST_PROP_OR(inst, data_hold_time, 0),     \
 		.clock_gate_offset = DT_INST_PROP(inst, clock_gate_offset),     \
 		.pcfg = PINCTRL_DT_INST_DEV_CONFIG_GET(inst),                   \
 		.target_enable = DT_INST_PROP(inst, target_enable),             \

dts/bindings/i2c/ite,enhance-i2c.yaml

@@ -18,6 +18,23 @@ properties:
       SCL cycle = 2 * (psr + prescale_tweak + 2) *
                   SMBus clock cycle
 
+  data-hold-time:
+    type: int
+    default: 3
+    enum:
+      - 3
+      - 4
+      - 5
+      - 6
+      - 7
+      - 8
+      - 9
+      - 10
+    description: |
+      This option is used to configure the data hold time of the I2C.
+      The unit is number of SMB clock cycles.  The time calculation
+      is (data-hold-time / smb_clk) seconds.
+
   target-enable:
     type: boolean
     description: |