Commit 4b6358e1 authored by Abdel Alkuor's avatar Abdel Alkuor Committed by Guenter Roeck
Browse files

hwmon: (lm75) Add AMS AS6200 temperature sensor 



as6200 is a temperature sensor with 0.0625°C resolution and a
range between -40°C to 125°C.

By default, the driver configures as6200 as following:
- Converstion rate: 8 Hz
- Conversion mode: continuous
- Consecutive fault counts: 4 samples
- Alert state: high polarity
- Alert mode: comparator mode

Interrupt is supported for the alert pin.

Signed-off-by: default avatarAbdel Alkuor <alkuor@gmail.com>
Link: https://lore.kernel.org/r/d1686678991bf8ee0d00cb08ca046798f37ca4b3.1703127334.git.alkuor@gmail.com


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent de9c6033

Documentation/hwmon/lm75.rst

+10 −0
Original line number Diff line number Diff line
@@ -133,6 +133,16 @@ Supported chips: 


               https://www.nxp.com/docs/en/data-sheet/PCT2075.pdf



  * AMS OSRAM AS6200



    Prefix: 'as6200'



    Addresses scanned: none



    Datasheet: Publicly available at the AMS website



               https://ams.com/documents/20143/36005/AS6200_DS000449_4-00.pdf



Author: Frodo Looijaard <frodol@dds.nl>



Description

drivers/hwmon/lm75.c

+94 −14
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 


#include <linux/module.h>

#include <linux/init.h>

#include <linux/interrupt.h>

#include <linux/slab.h>

#include <linux/jiffies.h>

#include <linux/i2c.h>
@@ -24,6 +25,7 @@ 


enum lm75_type {		/* keep sorted in alphabetical order */

	adt75,

	as6200,

	at30ts74,

	ds1775,

	ds75,
@@ -54,6 +56,7 @@ enum lm75_type { /* keep sorted in alphabetical order */ 


/**

 * struct lm75_params - lm75 configuration parameters.

 * @config_reg_16bits:	Configure register size is 2 bytes.

 * @set_mask:		Bits to set in configuration register when configuring

 *			the chip.

 * @clr_mask:		Bits to clear in configuration register when configuring
@@ -74,17 +77,20 @@ enum lm75_type { /* keep sorted in alphabetical order */ 
 * @sample_times:	All the possible sample times to be set. Mandatory if

 *			num_sample_times is larger than 1. If set, number of

 *			entries must match num_sample_times.

 * @alarm:		Alarm bit is supported.

 */



struct lm75_params {

	u8			set_mask;

	u8			clr_mask;

	bool			config_reg_16bits;

	u16			set_mask;

	u16			clr_mask;

	u8			default_resolution;

	u8			resolution_limits;

	const u8		*resolutions;

	unsigned int		default_sample_time;

	u8			num_sample_times;

	const unsigned int	*sample_times;

	bool			alarm;

};



/* Addresses scanned */
@@ -103,8 +109,8 @@ struct lm75_data { 
	struct i2c_client		*client;

	struct regmap			*regmap;

	struct regulator		*vs;

	u8				orig_conf;

	u8				current_conf;

	u16				orig_conf;

	u16				current_conf;

	u8				resolution;	/* In bits, 9 to 16 */

	unsigned int			sample_time;	/* In ms */

	enum lm75_type			kind;
@@ -127,6 +133,15 @@ static const struct lm75_params device_params[] = { 
		.default_resolution = 12,

		.default_sample_time = MSEC_PER_SEC / 10,

	},

	[as6200] = {

		.config_reg_16bits = true,

		.set_mask = 0x94C0,	/* 8 sample/s, 4 CF, positive polarity */

		.default_resolution = 12,

		.default_sample_time = 125,

		.num_sample_times = 4,

		.sample_times = (unsigned int []){ 125, 250, 1000, 4000 },

		.alarm = true,

	},

	[at30ts74] = {

		.set_mask = 3 << 5,	/* 12-bit mode*/

		.default_resolution = 12,
@@ -316,19 +331,22 @@ static inline long lm75_reg_to_mc(s16 temp, u8 resolution) 
	return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8);

}



static int lm75_write_config(struct lm75_data *data, u8 set_mask,

			     u8 clr_mask)

static int lm75_write_config(struct lm75_data *data, u16 set_mask,

			     u16 clr_mask)

{

	u8 value;

	unsigned int value;



	clr_mask |= LM75_SHUTDOWN;

	clr_mask |= LM75_SHUTDOWN << (8 * data->params->config_reg_16bits);

	value = data->current_conf & ~clr_mask;

	value |= set_mask;



	if (data->current_conf != value) {

		s32 err;



		err = i2c_smbus_write_byte_data(data->client, LM75_REG_CONF,

		if (data->params->config_reg_16bits)

			err = regmap_write(data->regmap, LM75_REG_CONF, value);

		else

			err = i2c_smbus_write_byte_data(data->client,

							LM75_REG_CONF,

							value);

		if (err)

			return err;
@@ -337,6 +355,27 @@ static int lm75_write_config(struct lm75_data *data, u8 set_mask, 
	return 0;

}



static int lm75_read_config(struct lm75_data *data)

{

	int ret;

	unsigned int status;



	if (data->params->config_reg_16bits) {

		ret = regmap_read(data->regmap, LM75_REG_CONF, &status);

		return ret ? ret : status;

	}



	return i2c_smbus_read_byte_data(data->client, LM75_REG_CONF);

}



static irqreturn_t lm75_alarm_handler(int irq, void *private)

{

	struct device *hwmon_dev = private;



	hwmon_notify_event(hwmon_dev, hwmon_temp, hwmon_temp_alarm, 0);

	return IRQ_HANDLED;

}



static int lm75_read(struct device *dev, enum hwmon_sensor_types type,

		     u32 attr, int channel, long *val)

{
@@ -365,6 +404,9 @@ static int lm75_read(struct device *dev, enum hwmon_sensor_types type, 
		case hwmon_temp_max_hyst:

			reg = LM75_REG_HYST;

			break;

		case hwmon_temp_alarm:

			reg = LM75_REG_CONF;

			break;

		default:

			return -EINVAL;

		}
@@ -372,7 +414,17 @@ static int lm75_read(struct device *dev, enum hwmon_sensor_types type, 
		if (err < 0)

			return err;



		if (attr == hwmon_temp_alarm) {

			switch (data->kind) {

			case as6200:

				*val = (regval >> 5) & 0x1;

				break;

			default:

				return -EINVAL;

			}

		} else {

			*val = lm75_reg_to_mc(regval, data->resolution);

		}

		break;

	default:

		return -EINVAL;
@@ -435,6 +487,7 @@ static int lm75_update_interval(struct device *dev, long val) 
			data->resolution = data->params->resolutions[index];

		break;

	case tmp112:

	case as6200:

		err = regmap_read(data->regmap, LM75_REG_CONF, &reg);

		if (err < 0)

			return err;
@@ -502,6 +555,10 @@ static umode_t lm75_is_visible(const void *data, enum hwmon_sensor_types type, 
		case hwmon_temp_max:

		case hwmon_temp_max_hyst:

			return 0644;

		case hwmon_temp_alarm:

			if (config_data->params->alarm)

				return 0444;

			break;

		}

		break;

	default:
@@ -514,7 +571,8 @@ static const struct hwmon_channel_info * const lm75_info[] = { 
	HWMON_CHANNEL_INFO(chip,

			   HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL),

	HWMON_CHANNEL_INFO(temp,

			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST),

			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST |

			   HWMON_T_ALARM),

	NULL

};
@@ -622,7 +680,7 @@ static int lm75_probe(struct i2c_client *client) 
		return err;



	/* Cache original configuration */

	status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);

	status = lm75_read_config(data);

	if (status < 0) {

		dev_dbg(dev, "Can't read config? %d\n", status);

		return status;
@@ -645,6 +703,23 @@ static int lm75_probe(struct i2c_client *client) 
	if (IS_ERR(hwmon_dev))

		return PTR_ERR(hwmon_dev);



	if (client->irq) {

		if (data->params->alarm) {

			err = devm_request_threaded_irq(dev,

							client->irq,

							NULL,

							&lm75_alarm_handler,

							IRQF_ONESHOT,

							client->name,

							hwmon_dev);

			if (err)

				return err;

		} else {

			 /* alarm is only supported for chips with alarm bit */

			dev_err(dev, "alarm interrupt is not supported\n");

		}

	}



	dev_info(dev, "%s: sensor '%s'\n", dev_name(hwmon_dev), client->name);



	return 0;
@@ -652,6 +727,7 @@ static int lm75_probe(struct i2c_client *client) 


static const struct i2c_device_id lm75_ids[] = {

	{ "adt75", adt75, },

	{ "as6200", as6200, },

	{ "at30ts74", at30ts74, },

	{ "ds1775", ds1775, },

	{ "ds75", ds75, },
@@ -688,6 +764,10 @@ static const struct of_device_id __maybe_unused lm75_of_match[] = { 
		.compatible = "adi,adt75",

		.data = (void *)adt75

	},

	{

		.compatible = "ams,as6200",

		.data = (void *)as6200

	},

	{

		.compatible = "atmel,at30ts74",

		.data = (void *)at30ts74