drivers: i2c: i2c_dw: Add capability for handling reset device

Reset the device on initializing if reset-node is available in dts.
`snps,desingware-i2c` does not define reset-node itself.
Add more of an element that inherits `reset-device.yaml` to
the `compatible` section to allow defining the reset-node
for using this feature.

For example.

```
compatible = "reset-device-inherit-node", "snps,designware-i2c";
```

Signed-off-by: TOKITA Hiroshi <[email protected]>

Author: soburi

drivers/i2c/i2c_dw.c

@@ -21,6 +21,9 @@
 #if defined(CONFIG_PINCTRL)
 #include <zephyr/drivers/pinctrl.h>
 #endif
+#if defined(CONFIG_RESET)
+#include <zephyr/drivers/reset.h>
+#endif
 
 #include <errno.h>
 #include <zephyr/sys/sys_io.h>
@@ -847,6 +850,15 @@ static int i2c_dw_initialize(const struct device *dev)
 	union ic_con_register ic_con;
 	int ret = 0;
 
+#if defined(CONFIG_RESET)
+	if (rom->reset.dev) {
+		ret = reset_line_toggle_dt(&rom->reset);
+		if (ret) {
+			return ret;
+		}
+	}
+#endif
+
 #if defined(CONFIG_PINCTRL)
 	ret = pinctrl_apply_state(rom->pcfg, PINCTRL_STATE_DEFAULT);
 	if (ret) {
@@ -922,6 +934,14 @@ static int i2c_dw_initialize(const struct device *dev)
 #define PINCTRL_DW_CONFIG(n)
 #endif
 
+#if defined(CONFIG_RESET)
+#define RESET_DW_CONFIG(n)                                                    \
+	IF_ENABLED(DT_INST_NODE_HAS_PROP(0, resets),                          \
+		   (.reset = RESET_DT_SPEC_INST_GET(n),))
+#else
+#define RESET_DW_CONFIG(n)
+#endif
+
 #define I2C_DW_INIT_PCIE0(n)
 #define I2C_DW_INIT_PCIE1(n) DEVICE_PCIE_INST_INIT(n, pcie),
 #define I2C_DW_INIT_PCIE(n) \
@@ -985,6 +1005,7 @@ static int i2c_dw_initialize(const struct device *dev)
 		I2C_CONFIG_REG_INIT(n)                                        \
 		.config_func = i2c_config_##n,                                \
 		.bitrate = DT_INST_PROP(n, clock_frequency),                  \
+		RESET_DW_CONFIG(n)                                            \
 		PINCTRL_DW_CONFIG(n)                                          \
 		I2C_DW_INIT_PCIE(n)                                           \
 	};                                                                    \

drivers/i2c/i2c_dw.h

@@ -18,6 +18,10 @@ BUILD_ASSERT(IS_ENABLED(CONFIG_PCIE), "DW I2C in DT needs CONFIG_PCIE");
 #include <zephyr/drivers/pcie/pcie.h>
 #endif
 
+#if defined(CONFIG_RESET)
+#include <zephyr/drivers/reset.h>
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -93,6 +97,9 @@ struct i2c_dw_rom_config {
 #if defined(CONFIG_PINCTRL)
 	const struct pinctrl_dev_config *pcfg;
 #endif
+#if defined(CONFIG_RESET)
+	const struct reset_dt_spec reset;
+#endif
 
 #if DT_ANY_INST_ON_BUS_STATUS_OKAY(pcie)
 	struct pcie_dev *pcie;