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Diffstat (limited to 'drivers/hwmon/ads7828.c')
-rw-r--r--drivers/hwmon/ads7828.c232
1 files changed, 109 insertions, 123 deletions
diff --git a/drivers/hwmon/ads7828.c b/drivers/hwmon/ads7828.c
index ba962ac4b81f..436637264056 100644
--- a/drivers/hwmon/ads7828.c
+++ b/drivers/hwmon/ads7828.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* ads7828.c - driver for TI ADS7828 8-channel A/D converter and compatibles
* (C) 2007 EADS Astrium
@@ -8,21 +9,7 @@
*
* ADS7830 support, by Guillaume Roguez <guillaume.roguez@savoirfairelinux.com>
*
- * For further information, see the Documentation/hwmon/ads7828 file.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * For further information, see the Documentation/hwmon/ads7828.rst file.
*/
#include <linux/err.h>
@@ -30,14 +17,14 @@
#include <linux/hwmon-sysfs.h>
#include <linux/i2c.h>
#include <linux/init.h>
-#include <linux/jiffies.h>
#include <linux/module.h>
-#include <linux/mutex.h>
+#include <linux/of.h>
#include <linux/platform_data/ads7828.h>
+#include <linux/regmap.h>
#include <linux/slab.h>
+#include <linux/regulator/consumer.h>
/* The ADS7828 registers */
-#define ADS7828_NCH 8 /* 8 channels supported */
#define ADS7828_CMD_SD_SE 0x80 /* Single ended inputs */
#define ADS7828_CMD_PD1 0x04 /* Internal vref OFF && A/D ON */
#define ADS7828_CMD_PD3 0x0C /* Internal vref ON && A/D ON */
@@ -50,17 +37,9 @@ enum ads7828_chips { ads7828, ads7830 };
/* Client specific data */
struct ads7828_data {
- struct device *hwmon_dev;
- struct mutex update_lock; /* Mutex protecting updates */
- unsigned long last_updated; /* Last updated time (in jiffies) */
- u16 adc_input[ADS7828_NCH]; /* ADS7828_NCH samples */
- bool valid; /* Validity flag */
- bool diff_input; /* Differential input */
- bool ext_vref; /* External voltage reference */
- unsigned int vref_mv; /* voltage reference value */
+ struct regmap *regmap;
u8 cmd_byte; /* Command byte without channel bits */
unsigned int lsb_resol; /* Resolution of the ADC sample LSB */
- s32 (*read_channel)(const struct i2c_client *client, u8 command);
};
/* Command byte C2,C1,C0 - see datasheet */
@@ -69,54 +48,34 @@ static inline u8 ads7828_cmd_byte(u8 cmd, int ch)
return cmd | (((ch >> 1) | (ch & 0x01) << 2) << 4);
}
-/* Update data for the device (all 8 channels) */
-static struct ads7828_data *ads7828_update_device(struct device *dev)
-{
- struct i2c_client *client = to_i2c_client(dev);
- struct ads7828_data *data = i2c_get_clientdata(client);
-
- mutex_lock(&data->update_lock);
-
- if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
- || !data->valid) {
- unsigned int ch;
- dev_dbg(&client->dev, "Starting ads7828 update\n");
-
- for (ch = 0; ch < ADS7828_NCH; ch++) {
- u8 cmd = ads7828_cmd_byte(data->cmd_byte, ch);
- data->adc_input[ch] = data->read_channel(client, cmd);
- }
- data->last_updated = jiffies;
- data->valid = true;
- }
-
- mutex_unlock(&data->update_lock);
-
- return data;
-}
-
/* sysfs callback function */
-static ssize_t ads7828_show_in(struct device *dev, struct device_attribute *da,
- char *buf)
+static ssize_t ads7828_in_show(struct device *dev,
+ struct device_attribute *da, char *buf)
{
struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
- struct ads7828_data *data = ads7828_update_device(dev);
- unsigned int value = DIV_ROUND_CLOSEST(data->adc_input[attr->index] *
- data->lsb_resol, 1000);
+ struct ads7828_data *data = dev_get_drvdata(dev);
+ u8 cmd = ads7828_cmd_byte(data->cmd_byte, attr->index);
+ unsigned int regval;
+ int err;
- return sprintf(buf, "%d\n", value);
+ err = regmap_read(data->regmap, cmd, &regval);
+ if (err < 0)
+ return err;
+
+ return sprintf(buf, "%d\n",
+ DIV_ROUND_CLOSEST(regval * data->lsb_resol, 1000));
}
-static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ads7828_show_in, NULL, 0);
-static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ads7828_show_in, NULL, 1);
-static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, ads7828_show_in, NULL, 2);
-static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, ads7828_show_in, NULL, 3);
-static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, ads7828_show_in, NULL, 4);
-static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, ads7828_show_in, NULL, 5);
-static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, ads7828_show_in, NULL, 6);
-static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, ads7828_show_in, NULL, 7);
+static SENSOR_DEVICE_ATTR_RO(in0_input, ads7828_in, 0);
+static SENSOR_DEVICE_ATTR_RO(in1_input, ads7828_in, 1);
+static SENSOR_DEVICE_ATTR_RO(in2_input, ads7828_in, 2);
+static SENSOR_DEVICE_ATTR_RO(in3_input, ads7828_in, 3);
+static SENSOR_DEVICE_ATTR_RO(in4_input, ads7828_in, 4);
+static SENSOR_DEVICE_ATTR_RO(in5_input, ads7828_in, 5);
+static SENSOR_DEVICE_ATTR_RO(in6_input, ads7828_in, 6);
+static SENSOR_DEVICE_ATTR_RO(in7_input, ads7828_in, 7);
-static struct attribute *ads7828_attributes[] = {
+static struct attribute *ads7828_attrs[] = {
&sensor_dev_attr_in0_input.dev_attr.attr,
&sensor_dev_attr_in1_input.dev_attr.attr,
&sensor_dev_attr_in2_input.dev_attr.attr,
@@ -128,78 +87,92 @@ static struct attribute *ads7828_attributes[] = {
NULL
};
-static const struct attribute_group ads7828_group = {
- .attrs = ads7828_attributes,
-};
-
-static int ads7828_remove(struct i2c_client *client)
-{
- struct ads7828_data *data = i2c_get_clientdata(client);
+ATTRIBUTE_GROUPS(ads7828);
- hwmon_device_unregister(data->hwmon_dev);
- sysfs_remove_group(&client->dev.kobj, &ads7828_group);
+static const struct regmap_config ads2828_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 16,
+};
- return 0;
-}
+static const struct regmap_config ads2830_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+};
-static int ads7828_probe(struct i2c_client *client,
- const struct i2c_device_id *id)
+static int ads7828_probe(struct i2c_client *client)
{
- struct ads7828_platform_data *pdata = client->dev.platform_data;
+ struct device *dev = &client->dev;
+ struct ads7828_platform_data *pdata = dev_get_platdata(dev);
struct ads7828_data *data;
- int err;
-
- data = devm_kzalloc(&client->dev, sizeof(struct ads7828_data),
- GFP_KERNEL);
+ struct device *hwmon_dev;
+ unsigned int vref_mv = ADS7828_INT_VREF_MV;
+ unsigned int vref_uv;
+ bool diff_input = false;
+ bool ext_vref = false;
+ unsigned int regval;
+ enum ads7828_chips chip;
+ struct regulator *reg;
+
+ data = devm_kzalloc(dev, sizeof(struct ads7828_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
if (pdata) {
- data->diff_input = pdata->diff_input;
- data->ext_vref = pdata->ext_vref;
- if (data->ext_vref)
- data->vref_mv = pdata->vref_mv;
+ diff_input = pdata->diff_input;
+ ext_vref = pdata->ext_vref;
+ if (ext_vref && pdata->vref_mv)
+ vref_mv = pdata->vref_mv;
+ } else if (dev->of_node) {
+ diff_input = of_property_read_bool(dev->of_node,
+ "ti,differential-input");
+ reg = devm_regulator_get_optional(dev, "vref");
+ if (!IS_ERR(reg)) {
+ vref_uv = regulator_get_voltage(reg);
+ vref_mv = DIV_ROUND_CLOSEST(vref_uv, 1000);
+ if (vref_mv < ADS7828_EXT_VREF_MV_MIN ||
+ vref_mv > ADS7828_EXT_VREF_MV_MAX)
+ return -EINVAL;
+ ext_vref = true;
+ }
}
- /* Bound Vref with min/max values if it was provided */
- if (data->vref_mv)
- data->vref_mv = clamp_val(data->vref_mv,
- ADS7828_EXT_VREF_MV_MIN,
- ADS7828_EXT_VREF_MV_MAX);
- else
- data->vref_mv = ADS7828_INT_VREF_MV;
+ chip = (uintptr_t)i2c_get_match_data(client);
+
+ /* Bound Vref with min/max values */
+ vref_mv = clamp_val(vref_mv, ADS7828_EXT_VREF_MV_MIN,
+ ADS7828_EXT_VREF_MV_MAX);
/* ADS7828 uses 12-bit samples, while ADS7830 is 8-bit */
- if (id->driver_data == ads7828) {
- data->lsb_resol = DIV_ROUND_CLOSEST(data->vref_mv * 1000, 4096);
- data->read_channel = i2c_smbus_read_word_swapped;
+ if (chip == ads7828) {
+ data->lsb_resol = DIV_ROUND_CLOSEST(vref_mv * 1000, 4096);
+ data->regmap = devm_regmap_init_i2c(client,
+ &ads2828_regmap_config);
} else {
- data->lsb_resol = DIV_ROUND_CLOSEST(data->vref_mv * 1000, 256);
- data->read_channel = i2c_smbus_read_byte_data;
+ data->lsb_resol = DIV_ROUND_CLOSEST(vref_mv * 1000, 256);
+ data->regmap = devm_regmap_init_i2c(client,
+ &ads2830_regmap_config);
}
- data->cmd_byte = data->ext_vref ? ADS7828_CMD_PD1 : ADS7828_CMD_PD3;
- if (!data->diff_input)
- data->cmd_byte |= ADS7828_CMD_SD_SE;
-
- i2c_set_clientdata(client, data);
- mutex_init(&data->update_lock);
+ if (IS_ERR(data->regmap))
+ return PTR_ERR(data->regmap);
- err = sysfs_create_group(&client->dev.kobj, &ads7828_group);
- if (err)
- return err;
-
- data->hwmon_dev = hwmon_device_register(&client->dev);
- if (IS_ERR(data->hwmon_dev)) {
- err = PTR_ERR(data->hwmon_dev);
- goto error;
- }
-
- return 0;
+ data->cmd_byte = ext_vref ? ADS7828_CMD_PD1 : ADS7828_CMD_PD3;
+ if (!diff_input)
+ data->cmd_byte |= ADS7828_CMD_SD_SE;
-error:
- sysfs_remove_group(&client->dev.kobj, &ads7828_group);
- return err;
+ /*
+ * Datasheet specifies internal reference voltage is disabled by
+ * default. The internal reference voltage needs to be enabled and
+ * voltage needs to settle before getting valid ADC data. So perform a
+ * dummy read to enable the internal reference voltage.
+ */
+ if (!ext_vref)
+ regmap_read(data->regmap, data->cmd_byte, &regval);
+
+ hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
+ data,
+ ads7828_groups);
+ return PTR_ERR_OR_ZERO(hwmon_dev);
}
static const struct i2c_device_id ads7828_device_ids[] = {
@@ -209,14 +182,27 @@ static const struct i2c_device_id ads7828_device_ids[] = {
};
MODULE_DEVICE_TABLE(i2c, ads7828_device_ids);
+static const struct of_device_id __maybe_unused ads7828_of_match[] = {
+ {
+ .compatible = "ti,ads7828",
+ .data = (void *)ads7828
+ },
+ {
+ .compatible = "ti,ads7830",
+ .data = (void *)ads7830
+ },
+ { },
+};
+MODULE_DEVICE_TABLE(of, ads7828_of_match);
+
static struct i2c_driver ads7828_driver = {
.driver = {
.name = "ads7828",
+ .of_match_table = of_match_ptr(ads7828_of_match),
},
.id_table = ads7828_device_ids,
.probe = ads7828_probe,
- .remove = ads7828_remove,
};
module_i2c_driver(ads7828_driver);
generated by cgit (git 2.34.1) at 2025-12-25 09:18:27 +0000