[PATCH v2 2/2] hwmon: (lm75) Add AMS AS6200 temperature sensor
From: Abdel Alkuor
Date: Sun Dec 17 2023 - 23:54:22 EST
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.
Datasheet: https://ams.com/documents/20143/36005/AS6200_DS000449_4-00.pdf
Signed-off-by: Abdel Alkuor <alkuor@xxxxxxxxx>
---
Changes in v2:
- Incorporate as6200 into lm75 driver
Documentation/hwmon/lm75.rst | 10 +++
drivers/hwmon/lm75.c | 132 +++++++++++++++++++++++++++++------
2 files changed, 122 insertions(+), 20 deletions(-)
diff --git a/Documentation/hwmon/lm75.rst b/Documentation/hwmon/lm75.rst
index 8d0ab4ad5fb5..6adab608dd05 100644
--- a/Documentation/hwmon/lm75.rst
+++ b/Documentation/hwmon/lm75.rst
@@ -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@xxxxxx>
Description
diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
index 5b2ea05c951e..2d153f6729e0 100644
--- a/drivers/hwmon/lm75.c
+++ b/drivers/hwmon/lm75.c
@@ -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>
@@ -25,6 +26,7 @@
enum lm75_type { /* keep sorted in alphabetical order */
adt75,
+ as6200,
at30ts74,
ds1775,
ds75,
@@ -55,6 +57,7 @@ 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
@@ -75,17 +78,20 @@ 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 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 */
@@ -104,8 +110,8 @@ 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;
@@ -128,6 +134,15 @@ 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,
@@ -317,20 +332,23 @@ 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,
- value);
+ 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;
data->current_conf = value;
@@ -338,6 +356,33 @@ static int lm75_write_config(struct lm75_data *data, u8 set_mask,
return 0;
}
+static int lm75_read_config(struct lm75_data *data, u16 *config)
+{
+ int ret;
+ unsigned int status;
+
+ if (data->params->config_reg_16bits) {
+ ret = regmap_read(data->regmap, LM75_REG_CONF, &status);
+ } else {
+ ret = i2c_smbus_read_byte_data(data->client, LM75_REG_CONF);
+ status = ret;
+ }
+
+ if (ret < 0)
+ return ret;
+
+ *config = status;
+ return 0;
+}
+
+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)
{
@@ -366,6 +411,9 @@ 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;
}
@@ -373,7 +421,17 @@ static int lm75_read(struct device *dev, enum hwmon_sensor_types type,
if (err < 0)
return err;
- *val = lm75_reg_to_mc(regval, data->resolution);
+ 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;
@@ -436,6 +494,7 @@ 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, ®);
if (err < 0)
return err;
@@ -503,6 +562,9 @@ 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;
default:
@@ -515,7 +577,8 @@ 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
};
@@ -574,7 +637,7 @@ static int lm75_probe(struct i2c_client *client)
struct device *dev = &client->dev;
struct device *hwmon_dev;
struct lm75_data *data;
- int status, err;
+ int err;
enum lm75_type kind;
if (client->dev.of_node)
@@ -623,13 +686,13 @@ static int lm75_probe(struct i2c_client *client)
return err;
/* Cache original configuration */
- status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
- if (status < 0) {
- dev_dbg(dev, "Can't read config? %d\n", status);
- return status;
+ err = lm75_read_config(data, &data->current_conf);
+ if (err) {
+ dev_dbg(dev, "Can't read config? %d\n", err);
+ return err;
}
- data->orig_conf = status;
- data->current_conf = status;
+
+ data->orig_conf = data->current_conf;
err = lm75_write_config(data, data->params->set_mask,
data->params->clr_mask);
@@ -646,6 +709,30 @@ 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 {
+ /*
+ * Currently, alarm is only supported for chips with
+ * alarm bit.
+ * In the future, if alarm is needed for chips with
+ * no alarm bit, current temp needs to be compared
+ * against the max and max hyst values to set/clear
+ * the alarm state.
+ */
+ dev_warn(dev, "alarm interrupt is not supported\n");
+ }
+ }
+
dev_info(dev, "%s: sensor '%s'\n", dev_name(hwmon_dev), client->name);
return 0;
@@ -654,6 +741,7 @@ static int lm75_probe(struct i2c_client *client)
static const struct i2c_device_id lm75_ids[] = {
{ "adt75", adt75, },
{ "at30ts74", at30ts74, },
+ { "as6200", as6200, },
{ "ds1775", ds1775, },
{ "ds75", ds75, },
{ "ds7505", ds7505, },
@@ -689,6 +777,10 @@ 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
--
2.34.1