drivers: mfd: it8801_altctrl: Add alternate controller for MFD

IT8801 support GPIO alternate function switching.
Some GPIO pins can be switched as KSO or PWM function.

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

drivers/mfd/CMakeLists.txt

@@ -17,3 +17,4 @@ zephyr_library_sources_ifdef(CONFIG_NXP_LP_FLEXCOMM mfd_nxp_lp_flexcomm.c)
 zephyr_library_sources_ifdef(CONFIG_MFD_BD8LB600FS mfd_bd8lb600fs.c)
 zephyr_library_sources_ifdef(CONFIG_MFD_TLE9104 mfd_tle9104.c)
 zephyr_library_sources_ifdef(CONFIG_MFD_ITE_IT8801 mfd_ite_it8801.c)
+zephyr_library_sources_ifdef(CONFIG_MFD_ITE_IT8801_ALTCTRL mfd_it8801_altctrl.c)

drivers/mfd/Kconfig.it8801

@@ -9,3 +9,11 @@ config MFD_ITE_IT8801
 	help
 	  Enable the ITE IT8801 ioexpander multi-function device driver.
 	  This ioexpander provides a GPIO/PWM/Keyboard function via I2C bus.
+
+if MFD_ITE_IT8801
+
+config MFD_ITE_IT8801_ALTCTRL
+	bool "ITE IT8801 MFD alternate controller"
+	default y
+
+endif # MFD_ITE_IT8801

drivers/mfd/mfd_it8801_altctrl.c

@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2024 ITE Corporation. All Rights Reserved.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT ite_it8801_altctrl
+
+#include <zephyr/drivers/i2c.h>
+#include <zephyr/drivers/mfd/mfd_ite_it8801.h>
+#include <zephyr/dt-bindings/mfd/mfd_it8801_altctrl.h>
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(mfd_it8801_altctrl, LOG_LEVEL_ERR);
+
+struct mfd_altfunc_config {
+	/*  gpiocr register */
+	uint8_t reg_gpiocr;
+};
+
+int mfd_it8801_configure_pins(const struct i2c_dt_spec *i2c_dev, const struct device *dev,
+			      uint8_t pin, uint8_t func)
+{
+	const struct mfd_altfunc_config *config = dev->config;
+	int ret;
+	uint8_t reg_gpiocr = config->reg_gpiocr + pin;
+	uint8_t alt_val;
+
+	switch (func) {
+	case IT8801_ALT_FUNC_1:
+		/* Func1: Default GPIO setting */
+		alt_val = IT8801_GPIOAFS_FUN1;
+		break;
+	case IT8801_ALT_FUNC_2:
+		/* Func2: KSO or PWM setting */
+		alt_val = IT8801_GPIOAFS_FUN2;
+		break;
+	case IT8801_ALT_FUNC_3:
+		/* Func3: PWM setting */
+		alt_val = IT8801_GPIOAFS_FUN3;
+		break;
+	case IT8801_ALT_DEFAULT:
+		alt_val = IT8801_GPIOAFS_FUN1;
+		break;
+	default:
+		LOG_ERR("This function is not supported.");
+		return -EINVAL;
+	}
+
+	/* Common settings for alternate function. */
+	ret = i2c_reg_update_byte_dt(i2c_dev, reg_gpiocr, GENMASK(7, 6), alt_val << 6);
+	if (ret != 0) {
+		LOG_ERR("Failed to update gpiocr (ret %d)", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+#define MFD_IT8801_ALTCTRL_INIT(inst)                                                              \
+	static const struct mfd_altfunc_config it8801_mfd_alt_cfg_##inst = {                       \
+		.reg_gpiocr = DT_INST_REG_ADDR(inst),                                              \
+	};                                                                                         \
+	DEVICE_DT_INST_DEFINE(inst, NULL, NULL, NULL, &it8801_mfd_alt_cfg_##inst, POST_KERNEL,     \
+			      CONFIG_MFD_INIT_PRIORITY, NULL);
+DT_INST_FOREACH_STATUS_OKAY(MFD_IT8801_ALTCTRL_INIT)

dts/bindings/mfd/ite,it8801-altctrl.yaml

@@ -0,0 +1,12 @@
+# Copyright (c) 2024 ITE Corporation. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+description: ITE IT8801 GPIO controller node
+
+compatible: "ite,it8801-altctrl"
+
+include: base.yaml
+
+altctrl-cells:
+  - pin
+  - alt_func

dts/bindings/mfd/ite,it8801-mfd-map.yaml

@@ -0,0 +1,13 @@
+# Copyright (c) 2024 ITE Corporation. All Rights Reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+description: ITE IT8801 alternate controller node
+
+compatible: "ite,it8801-mfd-map"
+
+child-binding:
+  description: Child node to present the mapping of IT8801 altternate function
+  properties:
+    altctrls:
+      type: phandle-array
+      required: true

dts/riscv/ite/it8801-mfd-gpiocr.dtsi

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2024 ITE Corporation. All Rights Reserved.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/ {
+	it8801-mfd {
+		#address-cells = <1>;
+		#size-cells = <1>;
+
+		it8801_gpio0: gpiocr@0a {
+			compatible = "ite,it8801-altctrl";
+			reg = <0x0a 8>;
+			#altctrl-cells = <2>;
+		};
+
+		it8801_gpio1: gpiocr@12 {
+			compatible = "ite,it8801-altctrl";
+			reg = <0x12 6>;
+			#altctrl-cells = <2>;
+		};
+
+		it8801_gpio2: gpiocr@1a {
+			compatible = "ite,it8801-altctrl";
+			reg = <0x1a 4>;
+			#altctrl-cells = <2>;
+		};
+	};
+};

dts/riscv/ite/it8801-mfd-map.dtsi

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2024 ITE Corporation. All Rights Reserved.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <ite/it8801-mfd-gpiocr.dtsi>
+#include <zephyr/dt-bindings/mfd/mfd_it8801_altctrl.h>
+
+
+/ {
+	/* GPIO pin mapping to alternate function */
+	it8801-mfd-map {
+		compatible = "ite,it8801-mfd-map";
+
+		/* PWM alternate function */
+		pwm1_gp12_default: pwm1_gp12_default {
+			altctrls = <&it8801_gpio1 2 IT8801_ALT_FUNC_2>;
+		};
+		pwm2_gp13_default: pwm2_gp13_default {
+			altctrls = <&it8801_gpio1 3 IT8801_ALT_FUNC_2>;
+		};
+		pwm3_gp14_default: pwm3_gp14_default {
+			altctrls = <&it8801_gpio1 4 IT8801_ALT_FUNC_2>;
+		};
+		pwm4_gp15_default: pwm4_gp15_default {
+			altctrls = <&it8801_gpio1 5 IT8801_ALT_FUNC_2>;
+		};
+		pwm7_gp20_default: pwm7_gp20_default {
+			altctrls = <&it8801_gpio2 0 IT8801_ALT_FUNC_2>;
+		};
+		pwm8_gp23_default: pwm8_gp23_default {
+			altctrls = <&it8801_gpio2 3 IT8801_ALT_FUNC_3>;
+		};
+		pwm9_gp22_default: pwm9_gp22_default {
+			altctrls = <&it8801_gpio2 2 IT8801_ALT_FUNC_3>;
+		};
+
+		/* Keyboard alternate function */
+		kso18_gp01_default: kso18_gp01_default {
+			altctrls = <&it8801_gpio0 1 IT8801_ALT_FUNC_2>;
+		};
+		kso19_gp00_default: kso19_gp00_default {
+			altctrls = <&it8801_gpio0 0 IT8801_ALT_FUNC_2>;
+		};
+		kso20_gp23_default: kso20_gp23_default {
+			altctrls = <&it8801_gpio2 3 IT8801_ALT_FUNC_2>;
+		};
+		kso21_gp22_default: kso21_gp22_default {
+			altctrls = <&it8801_gpio2 2 IT8801_ALT_FUNC_2>;
+		};
+		kso22_gp21_default: kso22_gp21_default {
+			altctrls = <&it8801_gpio2 1 IT8801_ALT_FUNC_2>;
+		};
+	};
+};

include/zephyr/drivers/mfd/mfd_ite_it8801.h

@@ -87,6 +87,36 @@ static const struct it8801_vendor_id_t it8801_id_verify[] = {
 #define IT8801_PWMMCR_MCR_BREATHING 2
 #define IT8801_PWMMCR_MCR_ON        3
 
+/*
+ * For IT8801 MFD alternate function controller
+ */
+#define IT8801_DT_INST_MFDCTRL(inst, idx) DT_INST_PHANDLE_BY_IDX(inst, mfdctrl, idx)
+
+#define IT8801_DT_INST_MFDCTRL_LEN(inst) DT_INST_PROP_LEN_OR(inst, mfdctrl, 0)
+
+#define IT8801_DEV_MFD(idx, inst)                                                                  \
+	DEVICE_DT_GET(DT_PHANDLE(IT8801_DT_INST_MFDCTRL(inst, idx), altctrls))
+#define IT8801_DEV_MFD_PIN(idx, inst)  DT_PHA(IT8801_DT_INST_MFDCTRL(inst, idx), altctrls, pin)
+#define IT8801_DEV_MFD_FUNC(idx, inst) DT_PHA(IT8801_DT_INST_MFDCTRL(inst, idx), altctrls, alt_func)
+
+#define IT8801_DT_MFD_ITEMS_FUNC(idx, inst)                                                        \
+	{                                                                                          \
+		.gpiocr = IT8801_DEV_MFD(idx, inst),                                               \
+		.pin = IT8801_DEV_MFD_PIN(idx, inst),                                              \
+		.alt_func = IT8801_DEV_MFD_FUNC(idx, inst),                                        \
+	}
+
+#define IT8801_DT_MFD_ITEMS_LIST(inst)                                                             \
+	{LISTIFY(IT8801_DT_INST_MFDCTRL_LEN(inst),                                                 \
+		IT8801_DT_MFD_ITEMS_FUNC, (,),                                                     \
+		inst) }
+
+/*
+ * Configure alternate function pin
+ */
+int mfd_it8801_configure_pins(const struct i2c_dt_spec *i2c_dev, const struct device *dev,
+			      uint8_t pin, uint8_t func);
+
 /* Define the IT8801 MFD interrupt callback function handler */
 typedef void (*it8801_callback_handler_t)(const struct device *dev);
 

include/zephyr/dt-bindings/mfd/mfd_it8801_altctrl.h

@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) 2024 ITE Technology Corporation.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#ifndef ZEPHYR_INCLUDE_DT_BINDINGS_MFD_IT8801_ALTCTRL_H_
+#define ZEPHYR_INCLUDE_DT_BINDINGS_MFD_IT8801_ALTCTRL_H_
+
+/**
+ * @brief PIN alternate function.
+ */
+#define IT8801_ALT_FUNC_1  0U
+#define IT8801_ALT_FUNC_2  1U
+#define IT8801_ALT_FUNC_3  2U
+#define IT8801_ALT_DEFAULT 3U
+
+#endif /* ZEPHYR_INCLUDE_DT_BINDINGS_MFD_IT8801_ALTCTRL_H_ */