[linux-block.git] / drivers / hwmon / oxp-sensors.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Platform driver for OXP Handhelds that expose fan reading and control
 * via hwmon sysfs.
 *
 * Old boards have the same DMI strings and they are told appart by the
 * boot cpu vendor (Intel/AMD). Currently only AMD boards are supported
 * but the code is made to be simple to add other handheld boards in the
 * future.
 * Fan control is provided via pwm interface in the range [0-255].
 * Old AMD boards use [0-100] as range in the EC, the written value is
 * scaled to accommodate for that. Newer boards like the mini PRO and
 * AOK ZOE are not scaled but have the same EC layout.
 *
 * Copyright (C) 2022 Joaquín I. Aramendía <samsagax@gmail.com>
 */

#include <linux/acpi.h>
#include <linux/dev_printk.h>
#include <linux/dmi.h>
#include <linux/hwmon.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/processor.h>

/* Handle ACPI lock mechanism */
static u32 oxp_mutex;

#define ACPI_LOCK_DELAY_MS	500

static bool lock_global_acpi_lock(void)
{
	return ACPI_SUCCESS(acpi_acquire_global_lock(ACPI_LOCK_DELAY_MS, &oxp_mutex));
}

static bool unlock_global_acpi_lock(void)
{
	return ACPI_SUCCESS(acpi_release_global_lock(oxp_mutex));
}

enum oxp_board {
	aok_zoe_a1 = 1,
	oxp_mini_amd,
	oxp_mini_amd_pro,
};

static enum oxp_board board;

#define OXP_SENSOR_FAN_REG		0x76 /* Fan reading is 2 registers long */
#define OXP_SENSOR_PWM_ENABLE_REG	0x4A /* PWM enable is 1 register long */
#define OXP_SENSOR_PWM_REG		0x4B /* PWM reading is 1 register long */

static const struct dmi_system_id dmi_table[] = {
	{
		.matches = {
			DMI_MATCH(DMI_BOARD_VENDOR, "AOKZOE"),
			DMI_EXACT_MATCH(DMI_BOARD_NAME, "AOKZOE A1 AR07"),
		},
		.driver_data = (void *) &(enum oxp_board) {aok_zoe_a1},
	},
	{
		.matches = {
			DMI_MATCH(DMI_BOARD_VENDOR, "ONE-NETBOOK"),
			DMI_EXACT_MATCH(DMI_BOARD_NAME, "ONE XPLAYER"),
		},
		.driver_data = (void *) &(enum oxp_board) {oxp_mini_amd},
	},
	{
		.matches = {
			DMI_MATCH(DMI_BOARD_VENDOR, "ONE-NETBOOK"),
			DMI_EXACT_MATCH(DMI_BOARD_NAME, "ONEXPLAYER Mini Pro"),
		},
		.driver_data = (void *) &(enum oxp_board) {oxp_mini_amd_pro},
	},
	{},
};

/* Helper functions to handle EC read/write */
static int read_from_ec(u8 reg, int size, long *val)
{
	int i;
	int ret;
	u8 buffer;

	if (!lock_global_acpi_lock())
		return -EBUSY;

	*val = 0;
	for (i = 0; i < size; i++) {
		ret = ec_read(reg + i, &buffer);
		if (ret)
			return ret;
		*val <<= i * 8;
		*val += buffer;
	}

	if (!unlock_global_acpi_lock())
		return -EBUSY;

	return 0;
}

static int write_to_ec(const struct device *dev, u8 reg, u8 value)
{
	int ret;

	if (!lock_global_acpi_lock())
		return -EBUSY;

	ret = ec_write(reg, value);

	if (!unlock_global_acpi_lock())
		return -EBUSY;

	return ret;
}

static int oxp_pwm_enable(const struct device *dev)
{
	return write_to_ec(dev, OXP_SENSOR_PWM_ENABLE_REG, 0x01);
}

static int oxp_pwm_disable(const struct device *dev)
{
	return write_to_ec(dev, OXP_SENSOR_PWM_ENABLE_REG, 0x00);
}

/* Callbacks for hwmon interface */
static umode_t oxp_ec_hwmon_is_visible(const void *drvdata,
				       enum hwmon_sensor_types type, u32 attr, int channel)
{
	switch (type) {
	case hwmon_fan:
		return 0444;
	case hwmon_pwm:
		return 0644;
	default:
		return 0;
	}
}

static int oxp_platform_read(struct device *dev, enum hwmon_sensor_types type,
			     u32 attr, int channel, long *val)
{
	int ret;

	switch (type) {
	case hwmon_fan:
		switch (attr) {
		case hwmon_fan_input:
			return read_from_ec(OXP_SENSOR_FAN_REG, 2, val);
		default:
			break;
		}
		break;
	case hwmon_pwm:
		switch (attr) {
		case hwmon_pwm_input:
			ret = read_from_ec(OXP_SENSOR_PWM_REG, 1, val);
			if (ret)
				return ret;
			if (board == oxp_mini_amd)
				*val = (*val * 255) / 100;
			return 0;
		case hwmon_pwm_enable:
			return read_from_ec(OXP_SENSOR_PWM_ENABLE_REG, 1, val);
		default:
			break;
		}
		break;
	default:
		break;
	}
	return -EOPNOTSUPP;
}

static int oxp_platform_write(struct device *dev, enum hwmon_sensor_types type,
			      u32 attr, int channel, long val)
{
	switch (type) {
	case hwmon_pwm:
		switch (attr) {
		case hwmon_pwm_enable:
			if (val == 1)
				return oxp_pwm_enable(dev);
			else if (val == 0)
				return oxp_pwm_disable(dev);
			return -EINVAL;
		case hwmon_pwm_input:
			if (val < 0 || val > 255)
				return -EINVAL;
			if (board == oxp_mini_amd)
				val = (val * 100) / 255;
			return write_to_ec(dev, OXP_SENSOR_PWM_REG, val);
		default:
			break;
		}
		break;
	default:
		break;
	}
	return -EOPNOTSUPP;
}

/* Known sensors in the OXP EC controllers */
static const struct hwmon_channel_info *oxp_platform_sensors[] = {
	HWMON_CHANNEL_INFO(fan,
			   HWMON_F_INPUT),
	HWMON_CHANNEL_INFO(pwm,
			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE),
	NULL,
};

static const struct hwmon_ops oxp_ec_hwmon_ops = {
	.is_visible = oxp_ec_hwmon_is_visible,
	.read = oxp_platform_read,
	.write = oxp_platform_write,
};

static const struct hwmon_chip_info oxp_ec_chip_info = {
	.ops = &oxp_ec_hwmon_ops,
	.info = oxp_platform_sensors,
};

/* Initialization logic */
static int oxp_platform_probe(struct platform_device *pdev)
{
	const struct dmi_system_id *dmi_entry;
	struct device *dev = &pdev->dev;
	struct device *hwdev;

	/*
	 * Have to check for AMD processor here because DMI strings are the
	 * same between Intel and AMD boards, the only way to tell them appart
	 * is the CPU.
	 * Intel boards seem to have different EC registers and values to
	 * read/write.
	 */
	dmi_entry = dmi_first_match(dmi_table);
	if (!dmi_entry || boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
		return -ENODEV;

	board = *((enum oxp_board *) dmi_entry->driver_data);

	hwdev = devm_hwmon_device_register_with_info(dev, "oxpec", NULL,
						     &oxp_ec_chip_info, NULL);

	return PTR_ERR_OR_ZERO(hwdev);
}

static struct platform_driver oxp_platform_driver = {
	.driver = {
		.name = "oxp-platform",
	},
	.probe = oxp_platform_probe,
};

static struct platform_device *oxp_platform_device;

static int __init oxp_platform_init(void)
{
	oxp_platform_device =
		platform_create_bundle(&oxp_platform_driver,
				       oxp_platform_probe, NULL, 0, NULL, 0);

	return PTR_ERR_OR_ZERO(oxp_platform_device);
}

static void __exit oxp_platform_exit(void)
{
	platform_device_unregister(oxp_platform_device);
	platform_driver_unregister(&oxp_platform_driver);
}

MODULE_DEVICE_TABLE(dmi, dmi_table);

module_init(oxp_platform_init);
module_exit(oxp_platform_exit);

MODULE_AUTHOR("Joaquín Ignacio Aramendía <samsagax@gmail.com>");
MODULE_DESCRIPTION("Platform driver that handles EC sensors of OneXPlayer devices");
MODULE_LICENSE("GPL");
Commit	Line	Data
ed264e8a JIA	1	// SPDX-License-Identifier: GPL-2.0+
	2	/*
	3	* Platform driver for OXP Handhelds that expose fan reading and control
	4	* via hwmon sysfs.
	5	*
3ca0f12a	6	* Old boards have the same DMI strings and they are told appart by the
ed264e8a JIA	7	* boot cpu vendor (Intel/AMD). Currently only AMD boards are supported
	8	* but the code is made to be simple to add other handheld boards in the
	9	* future.
3ca0f12a JIA	10	* Fan control is provided via pwm interface in the range [0-255].
	11	* Old AMD boards use [0-100] as range in the EC, the written value is
	12	* scaled to accommodate for that. Newer boards like the mini PRO and
	13	* AOK ZOE are not scaled but have the same EC layout.
ed264e8a JIA	14	*
	15	* Copyright (C) 2022 Joaquín I. Aramendía <samsagax@gmail.com>
	16	*/
	17
	18	#include <linux/acpi.h>
	19	#include <linux/dev_printk.h>
	20	#include <linux/dmi.h>
	21	#include <linux/hwmon.h>
	22	#include <linux/init.h>
	23	#include <linux/kernel.h>
	24	#include <linux/module.h>
	25	#include <linux/platform_device.h>
	26	#include <linux/processor.h>
	27
	28	/* Handle ACPI lock mechanism */
	29	static u32 oxp_mutex;
	30
	31	#define ACPI_LOCK_DELAY_MS 500
	32
	33	static bool lock_global_acpi_lock(void)
	34	{
	35	return ACPI_SUCCESS(acpi_acquire_global_lock(ACPI_LOCK_DELAY_MS, &oxp_mutex));
	36	}
	37
	38	static bool unlock_global_acpi_lock(void)
	39	{
	40	return ACPI_SUCCESS(acpi_release_global_lock(oxp_mutex));
	41	}
	42
3ca0f12a JIA	43	enum oxp_board {
	44	aok_zoe_a1 = 1,
	45	oxp_mini_amd,
	46	oxp_mini_amd_pro,
	47	};
	48
	49	static enum oxp_board board;
	50
ed264e8a JIA	51	#define OXP_SENSOR_FAN_REG 0x76 /* Fan reading is 2 registers long */
	52	#define OXP_SENSOR_PWM_ENABLE_REG 0x4A /* PWM enable is 1 register long */
	53	#define OXP_SENSOR_PWM_REG 0x4B /* PWM reading is 1 register long */
	54
	55	static const struct dmi_system_id dmi_table[] = {
3ca0f12a JIA	56	{
	57	.matches = {
	58	DMI_MATCH(DMI_BOARD_VENDOR, "AOKZOE"),
	59	DMI_EXACT_MATCH(DMI_BOARD_NAME, "AOKZOE A1 AR07"),
	60	},
	61	.driver_data = (void *) &(enum oxp_board) {aok_zoe_a1},
	62	},
ed264e8a JIA	63	{
	64	.matches = {
	65	DMI_MATCH(DMI_BOARD_VENDOR, "ONE-NETBOOK"),
	66	DMI_EXACT_MATCH(DMI_BOARD_NAME, "ONE XPLAYER"),
	67	},
3ca0f12a JIA	68	.driver_data = (void *) &(enum oxp_board) {oxp_mini_amd},
	69	},
	70	{
	71	.matches = {
	72	DMI_MATCH(DMI_BOARD_VENDOR, "ONE-NETBOOK"),
	73	DMI_EXACT_MATCH(DMI_BOARD_NAME, "ONEXPLAYER Mini Pro"),
	74	},
	75	.driver_data = (void *) &(enum oxp_board) {oxp_mini_amd_pro},
ed264e8a JIA	76	},
	77	{},
	78	};
	79
	80	/* Helper functions to handle EC read/write */
	81	static int read_from_ec(u8 reg, int size, long *val)
	82	{
	83	int i;
	84	int ret;
	85	u8 buffer;
	86
	87	if (!lock_global_acpi_lock())
	88	return -EBUSY;
	89
	90	*val = 0;
	91	for (i = 0; i < size; i++) {
	92	ret = ec_read(reg + i, &buffer);
	93	if (ret)
	94	return ret;
	95	val <<= i 8;
	96	*val += buffer;
	97	}
	98
	99	if (!unlock_global_acpi_lock())
	100	return -EBUSY;
	101
	102	return 0;
	103	}
	104
	105	static int write_to_ec(const struct device *dev, u8 reg, u8 value)
	106	{
	107	int ret;
	108
	109	if (!lock_global_acpi_lock())
	110	return -EBUSY;
	111
	112	ret = ec_write(reg, value);
	113
	114	if (!unlock_global_acpi_lock())
	115	return -EBUSY;
	116
	117	return ret;
	118	}
	119
	120	static int oxp_pwm_enable(const struct device *dev)
	121	{
	122	return write_to_ec(dev, OXP_SENSOR_PWM_ENABLE_REG, 0x01);
	123	}
	124
	125	static int oxp_pwm_disable(const struct device *dev)
	126	{
	127	return write_to_ec(dev, OXP_SENSOR_PWM_ENABLE_REG, 0x00);
	128	}
	129
	130	/* Callbacks for hwmon interface */
	131	static umode_t oxp_ec_hwmon_is_visible(const void *drvdata,
	132	enum hwmon_sensor_types type, u32 attr, int channel)
	133	{
	134	switch (type) {
	135	case hwmon_fan:
	136	return 0444;
	137	case hwmon_pwm:
	138	return 0644;
	139	default:
140	return 0;
141	}
142	}
143
144	static int oxp_platform_read(struct device *dev, enum hwmon_sensor_types type,
145	u32 attr, int channel, long *val)
146	{
147	int ret;
148
149	switch (type) {
150	case hwmon_fan:
151	switch (attr) {
152	case hwmon_fan_input:
153	return read_from_ec(OXP_SENSOR_FAN_REG, 2, val);
154	default:
155	break;
156	}
157	break;
158	case hwmon_pwm:
159	switch (attr) {
160	case hwmon_pwm_input:
0cd3ba68	161	ret = read_from_ec(OXP_SENSOR_PWM_REG, 1, val);
ed264e8a JIA	162	if (ret)
ed264e8a JIA	163	return ret;
3ca0f12a JIA	164	if (board == oxp_mini_amd)
3ca0f12a JIA	165	val = (val * 255) / 100;
ed264e8a JIA	166	return 0;
	167	case hwmon_pwm_enable:
	168	return read_from_ec(OXP_SENSOR_PWM_ENABLE_REG, 1, val);
	169	default:
	170	break;
	171	}
	172	break;
	173	default:
	174	break;
	175	}
	176	return -EOPNOTSUPP;
	177	}
	178
	179	static int oxp_platform_write(struct device *dev, enum hwmon_sensor_types type,
	180	u32 attr, int channel, long val)
	181	{
	182	switch (type) {
	183	case hwmon_pwm:
	184	switch (attr) {
	185	case hwmon_pwm_enable:
	186	if (val == 1)
	187	return oxp_pwm_enable(dev);
	188	else if (val == 0)
	189	return oxp_pwm_disable(dev);
	190	return -EINVAL;
	191	case hwmon_pwm_input:
	192	if (val < 0 \|\| val > 255)
	193	return -EINVAL;
3ca0f12a JIA	194	if (board == oxp_mini_amd)
3ca0f12a JIA	195	val = (val * 100) / 255;
ed264e8a JIA	196	return write_to_ec(dev, OXP_SENSOR_PWM_REG, val);
	197	default:
	198	break;
	199	}
	200	break;
	201	default:
	202	break;
	203	}
	204	return -EOPNOTSUPP;
	205	}
	206
	207	/* Known sensors in the OXP EC controllers */
	208	static const struct hwmon_channel_info *oxp_platform_sensors[] = {
	209	HWMON_CHANNEL_INFO(fan,
	210	HWMON_F_INPUT),
	211	HWMON_CHANNEL_INFO(pwm,
	212	HWMON_PWM_INPUT \| HWMON_PWM_ENABLE),
	213	NULL,
	214	};
	215
	216	static const struct hwmon_ops oxp_ec_hwmon_ops = {
	217	.is_visible = oxp_ec_hwmon_is_visible,
	218	.read = oxp_platform_read,
	219	.write = oxp_platform_write,
	220	};
	221
	222	static const struct hwmon_chip_info oxp_ec_chip_info = {
	223	.ops = &oxp_ec_hwmon_ops,
	224	.info = oxp_platform_sensors,
	225	};
	226
	227	/* Initialization logic */
	228	static int oxp_platform_probe(struct platform_device *pdev)
	229	{
	230	const struct dmi_system_id *dmi_entry;
	231	struct device *dev = &pdev->dev;
	232	struct device *hwdev;
	233
	234	/*
	235	* Have to check for AMD processor here because DMI strings are the
	236	* same between Intel and AMD boards, the only way to tell them appart
	237	* is the CPU.
	238	* Intel boards seem to have different EC registers and values to
	239	* read/write.
	240	*/
	241	dmi_entry = dmi_first_match(dmi_table);
	242	if (!dmi_entry \|\| boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
	243	return -ENODEV;
	244
3ca0f12a JIA	245	board = ((enum oxp_board ) dmi_entry->driver_data);
3ca0f12a JIA	246
ed264e8a JIA	247	hwdev = devm_hwmon_device_register_with_info(dev, "oxpec", NULL,
	248	&oxp_ec_chip_info, NULL);
	249
	250	return PTR_ERR_OR_ZERO(hwdev);
	251	}
	252
	253	static struct platform_driver oxp_platform_driver = {
	254	.driver = {
	255	.name = "oxp-platform",
	256	},
	257	.probe = oxp_platform_probe,
	258	};
	259
	260	static struct platform_device *oxp_platform_device;
	261
	262	static int __init oxp_platform_init(void)
	263	{
	264	oxp_platform_device =
	265	platform_create_bundle(&oxp_platform_driver,
	266	oxp_platform_probe, NULL, 0, NULL, 0);
	267
	268	return PTR_ERR_OR_ZERO(oxp_platform_device);
	269	}
	270
	271	static void __exit oxp_platform_exit(void)
	272	{
	273	platform_device_unregister(oxp_platform_device);
	274	platform_driver_unregister(&oxp_platform_driver);
	275	}
	276
	277	MODULE_DEVICE_TABLE(dmi, dmi_table);
	278
	279	module_init(oxp_platform_init);
	280	module_exit(oxp_platform_exit);
	281
	282	MODULE_AUTHOR("Joaquín Ignacio Aramendía <samsagax@gmail.com>");
	283	MODULE_DESCRIPTION("Platform driver that handles EC sensors of OneXPlayer devices");
	284	MODULE_LICENSE("GPL");