Orange Pi5 kernel

// 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 <shardy@redhat.com>
 *
 * ADS7830 support, by Guillaume Roguez <guillaume.roguez@savoirfairelinux.com>
 *
 * 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, &regval);
<------>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, &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[] = {
<------>{ "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 <shardy@redhat.com>");
MODULE_DESCRIPTION("Driver for TI ADS7828 A/D converter and compatibles");