1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * Power Management and GPIO expander driver for MPC8349E-mITX-compatible MCU
24  * I don't have specifications for the MCU firmware, I found this register
33 struct mcu {  struct
40 static struct mcu *glob_mcu;  argument
46 	struct mcu *mcu = glob_mcu;  in shutdown_thread_fn()  local
49 		ret = i2c_smbus_read_byte_data(mcu->client, MCU_REG_CTRL);  in shutdown_thread_fn()
51 			pr_err("MCU status reg read failed.\n");  in shutdown_thread_fn()
52 		mcu->reg_ctrl = ret;  in shutdown_thread_fn()
55 		if (mcu->reg_ctrl & MCU_CTRL_BTN) {  in shutdown_thread_fn()
56 			i2c_smbus_write_byte_data(mcu->client, MCU_REG_CTRL,  in shutdown_thread_fn()
57 						  mcu->reg_ctrl & ~MCU_CTRL_BTN);  in shutdown_thread_fn()
73 	struct mcu *mcu = glob_mcu;  in show_status()  local
75 	ret = i2c_smbus_read_byte_data(mcu->client, MCU_REG_CTRL);  in show_status()
77 		return -ENODEV;  in show_status()
78 	mcu->reg_ctrl = ret;  in show_status()
86 	struct mcu *mcu = glob_mcu;  in mcu_power_off()  local
88 	pr_info("Sending power-off request to the MCU...\n");  in mcu_power_off()
89 	mutex_lock(&mcu->lock);  in mcu_power_off()
90 	i2c_smbus_write_byte_data(mcu->client, MCU_REG_CTRL,  in mcu_power_off()
91 				  mcu->reg_ctrl | MCU_CTRL_POFF);  in mcu_power_off()
92 	mutex_unlock(&mcu->lock);  in mcu_power_off()
97 	struct mcu *mcu = gpiochip_get_data(gc);  in mcu_gpio_set()  local
101 	mutex_lock(&mcu->lock);  in mcu_gpio_set()
103 		mcu->reg_ctrl &= ~bit;  in mcu_gpio_set()
105 		mcu->reg_ctrl |= bit;  in mcu_gpio_set()
107 	ret = i2c_smbus_write_byte_data(mcu->client, MCU_REG_CTRL,  in mcu_gpio_set()
108 					mcu->reg_ctrl);  in mcu_gpio_set()
109 	mutex_unlock(&mcu->lock);  in mcu_gpio_set()
119 static int mcu_gpiochip_add(struct mcu *mcu)  in mcu_gpiochip_add()  argument
121 	struct device *dev = &mcu->client->dev;  in mcu_gpiochip_add()
122 	struct gpio_chip *gc = &mcu->gc;  in mcu_gpiochip_add()
124 	gc->owner = THIS_MODULE;  in mcu_gpiochip_add()
125 	gc->label = kasprintf(GFP_KERNEL, "%pfw", dev_fwnode(dev));  in mcu_gpiochip_add()
126 	gc->can_sleep = 1;  in mcu_gpiochip_add()
127 	gc->ngpio = MCU_NUM_GPIO;  in mcu_gpiochip_add()
128 	gc->base = -1;  in mcu_gpiochip_add()
129 	gc->set = mcu_gpio_set;  in mcu_gpiochip_add()
130 	gc->direction_output = mcu_gpio_dir_out;  in mcu_gpiochip_add()
131 	gc->parent = dev;  in mcu_gpiochip_add()
133 	return gpiochip_add_data(gc, mcu);  in mcu_gpiochip_add()
136 static void mcu_gpiochip_remove(struct mcu *mcu)  in mcu_gpiochip_remove()  argument
138 	kfree(mcu->gc.label);  in mcu_gpiochip_remove()
139 	gpiochip_remove(&mcu->gc);  in mcu_gpiochip_remove()
144 	struct mcu *mcu;  in mcu_probe()  local
147 	mcu = kzalloc(sizeof(*mcu), GFP_KERNEL);  in mcu_probe()
148 	if (!mcu)  in mcu_probe()
149 		return -ENOMEM;  in mcu_probe()
151 	mutex_init(&mcu->lock);  in mcu_probe()
152 	mcu->client = client;  in mcu_probe()
153 	i2c_set_clientdata(client, mcu);  in mcu_probe()
155 	ret = i2c_smbus_read_byte_data(mcu->client, MCU_REG_CTRL);  in mcu_probe()
158 	mcu->reg_ctrl = ret;  in mcu_probe()
160 	ret = mcu_gpiochip_add(mcu);  in mcu_probe()
166 		glob_mcu = mcu;  in mcu_probe()
168 		dev_info(&client->dev, "will provide power-off service\n");  in mcu_probe()
171 	if (device_create_file(&client->dev, &dev_attr_status))  in mcu_probe()
172 		dev_err(&client->dev,  in mcu_probe()
176 				      "mcu-i2c-shdn");  in mcu_probe()
180 	kfree(mcu);  in mcu_probe()
186 	struct mcu *mcu = i2c_get_clientdata(client);  in mcu_remove()  local
190 	device_remove_file(&client->dev, &dev_attr_status);  in mcu_remove()
192 	if (glob_mcu == mcu) {  in mcu_remove()
197 	mcu_gpiochip_remove(mcu);  in mcu_remove()
198 	kfree(mcu);  in mcu_remove()
202 	{ "mcu-mpc8349emitx", },
208 	{ .compatible = "fsl,mcu-mpc8349emitx", },
214 		.name = "mcu-mpc8349emitx",
225 		   "MPC8349E-mITX-compatible MCU");