123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218 |
- // 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
- *
- * This driver is based on the lm75 and other lm_sensors/hwmon drivers
- *
- * Written by Steve Hardy <[email protected]>
- *
- * ADS7830 support, by Guillaume Roguez <[email protected]>
- *
- * For further information, see the Documentation/hwmon/ads7828.rst file.
- */
- #include <linux/err.h>
- #include <linux/hwmon.h>
- #include <linux/hwmon-sysfs.h>
- #include <linux/i2c.h>
- #include <linux/init.h>
- #include <linux/module.h>
- #include <linux/of_device.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_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 */
- #define ADS7828_INT_VREF_MV 2500 /* Internal vref is 2.5V, 2500mV */
- #define ADS7828_EXT_VREF_MV_MIN 50 /* External vref min value 0.05V */
- #define ADS7828_EXT_VREF_MV_MAX 5250 /* External vref max value 5.25V */
- /* List of supported devices */
- enum ads7828_chips { ads7828, ads7830 };
- /* Client specific data */
- struct ads7828_data {
- struct regmap *regmap;
- u8 cmd_byte; /* Command byte without channel bits */
- unsigned int lsb_resol; /* Resolution of the ADC sample LSB */
- };
- /* Command byte C2,C1,C0 - see datasheet */
- static inline u8 ads7828_cmd_byte(u8 cmd, int ch)
- {
- return cmd | (((ch >> 1) | (ch & 0x01) << 2) << 4);
- }
- /* sysfs callback function */
- 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 = dev_get_drvdata(dev);
- u8 cmd = ads7828_cmd_byte(data->cmd_byte, attr->index);
- unsigned int regval;
- int err;
- err = regmap_read(data->regmap, cmd, ®val);
- if (err < 0)
- return err;
- return sprintf(buf, "%d\n",
- DIV_ROUND_CLOSEST(regval * data->lsb_resol, 1000));
- }
- 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_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,
- &sensor_dev_attr_in3_input.dev_attr.attr,
- &sensor_dev_attr_in4_input.dev_attr.attr,
- &sensor_dev_attr_in5_input.dev_attr.attr,
- &sensor_dev_attr_in6_input.dev_attr.attr,
- &sensor_dev_attr_in7_input.dev_attr.attr,
- NULL
- };
- ATTRIBUTE_GROUPS(ads7828);
- static const struct regmap_config ads2828_regmap_config = {
- .reg_bits = 8,
- .val_bits = 16,
- };
- static const struct regmap_config ads2830_regmap_config = {
- .reg_bits = 8,
- .val_bits = 8,
- };
- static const struct i2c_device_id ads7828_device_ids[];
- static int ads7828_probe(struct i2c_client *client)
- {
- struct device *dev = &client->dev;
- struct ads7828_platform_data *pdata = dev_get_platdata(dev);
- struct ads7828_data *data;
- 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) {
- 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;
- }
- }
- if (client->dev.of_node)
- chip = (enum ads7828_chips)
- of_device_get_match_data(&client->dev);
- else
- chip = i2c_match_id(ads7828_device_ids, client)->driver_data;
- /* 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 (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(vref_mv * 1000, 256);
- data->regmap = devm_regmap_init_i2c(client,
- &ads2830_regmap_config);
- }
- if (IS_ERR(data->regmap))
- return PTR_ERR(data->regmap);
- data->cmd_byte = ext_vref ? ADS7828_CMD_PD1 : ADS7828_CMD_PD3;
- if (!diff_input)
- data->cmd_byte |= ADS7828_CMD_SD_SE;
- /*
- * 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, ®val);
- 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[] = {
- { "ads7828", ads7828 },
- { "ads7830", ads7830 },
- { }
- };
- 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_new = ads7828_probe,
- };
- module_i2c_driver(ads7828_driver);
- MODULE_LICENSE("GPL");
- MODULE_AUTHOR("Steve Hardy <[email protected]>");
- MODULE_DESCRIPTION("Driver for TI ADS7828 A/D converter and compatibles");
|