hwmon: (ads7871) Convert to hwmon_device_register_with_info

Convert the ads7871 driver from the legacy hwmon_device_register() to the
modern hwmon_device_register_with_info() API. This migration simplifies
the driver by using the structured hwmon_channel_info approach and
prepares the codebase for the transition to a shared DMA-safe buffer.
While at it, fix checkpatch violations.

Signed-off-by: Tabrez Ahmed <tabreztalks@gmail.com>
Link: https://lore.kernel.org/r/20260502020844.110038-3-tabreztalks@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/ads7871.c b/drivers/hwmon/ads7871.c
index 9ee3ce01f130bbd8bf0a02b351d12cd5a75d3f02..805b3657362d195d3ac4008eea94fdfe5c8f3873 100644 (file)
--- a/drivers/hwmon/ads7871.c
+++ b/drivers/hwmon/ads7871.c
@@ -56,7 +56,6 @@
 #include <linux/init.h>
 #include <linux/spi/spi.h>
 #include <linux/hwmon.h>
-#include <linux/hwmon-sysfs.h>
 #include <linux/err.h>
 #include <linux/delay.h>
 
@@ -66,6 +65,16 @@ struct ads7871_data {
        struct spi_device *spi;
 };
 
+static umode_t ads7871_is_visible(const void *data,
+                                 enum hwmon_sensor_types type,
+                                 u32 attr, int channel)
+{
+       if (type == hwmon_in && attr == hwmon_in_input)
+               return 0444;
+
+       return 0;
+}
+
 static int ads7871_read_reg8(struct spi_device *spi, int reg)
 {
        int ret;
@@ -89,19 +98,20 @@ static int ads7871_read_reg16(struct spi_device *spi, int reg)
 static int ads7871_write_reg8(struct spi_device *spi, int reg, u8 val)
 {
        u8 tmp[2] = {reg, val};
+
        return spi_write(spi, tmp, sizeof(tmp));
 }
 
-static ssize_t voltage_show(struct device *dev, struct device_attribute *da,
-                           char *buf)
+static int ads7871_read(struct device *dev, enum hwmon_sensor_types type,
+                       u32 attr, int channel, long *val)
 {
        struct ads7871_data *pdata = dev_get_drvdata(dev);
        struct spi_device *spi = pdata->spi;
-       struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
-       int ret, val, i = 0;
-       uint8_t channel, mux_cnv;
+       int ret, raw_val, i = 0;
+       u8 mux_cnv;
 
-       channel = attr->index;
+       if (type != hwmon_in || attr != hwmon_in_input)
+               return -EOPNOTSUPP;
        /*
         * TODO: add support for conversions
         * other than single ended with a gain of 1
@@ -131,39 +141,34 @@ static ssize_t voltage_show(struct device *dev, struct device_attribute *da,
        }
 
        if (mux_cnv == 0) {
-               val = ads7871_read_reg16(spi, REG_LS_BYTE);
-               if (val < 0)
-                       return val;
+               raw_val = ads7871_read_reg16(spi, REG_LS_BYTE);
+               if (raw_val < 0)
+                       return raw_val;
+
                /*result in volts*10000 = (val/8192)*2.5*10000*/
-               val = ((val >> 2) * 25000) / 8192;
-               return sysfs_emit(buf, "%d\n", val);
+               *val = ((raw_val >> 2) * 25000) / 8192;
+               return 0;
        }
 
        return -ETIMEDOUT;
 }
 
-static SENSOR_DEVICE_ATTR_RO(in0_input, voltage, 0);
-static SENSOR_DEVICE_ATTR_RO(in1_input, voltage, 1);
-static SENSOR_DEVICE_ATTR_RO(in2_input, voltage, 2);
-static SENSOR_DEVICE_ATTR_RO(in3_input, voltage, 3);
-static SENSOR_DEVICE_ATTR_RO(in4_input, voltage, 4);
-static SENSOR_DEVICE_ATTR_RO(in5_input, voltage, 5);
-static SENSOR_DEVICE_ATTR_RO(in6_input, voltage, 6);
-static SENSOR_DEVICE_ATTR_RO(in7_input, voltage, 7);
-
-static struct attribute *ads7871_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,
+static const struct hwmon_channel_info * const ads7871_info[] = {
+       HWMON_CHANNEL_INFO(in,
+                          HWMON_I_INPUT, HWMON_I_INPUT, HWMON_I_INPUT, HWMON_I_INPUT,
+                          HWMON_I_INPUT, HWMON_I_INPUT, HWMON_I_INPUT, HWMON_I_INPUT),
        NULL
 };
 
-ATTRIBUTE_GROUPS(ads7871);
+static const struct hwmon_ops ads7871_hwmon_ops = {
+       .is_visible = ads7871_is_visible,
+       .read = ads7871_read,
+};
+
+static const struct hwmon_chip_info ads7871_chip_info = {
+       .ops = &ads7871_hwmon_ops,
+       .info = ads7871_info,
+};
 
 static int ads7871_probe(struct spi_device *spi)
 {
@@ -198,10 +203,10 @@ static int ads7871_probe(struct spi_device *spi)
                return -ENOMEM;
 
        pdata->spi = spi;
-
-       hwmon_dev = devm_hwmon_device_register_with_groups(dev, spi->modalias,
-                                                          pdata,
-                                                          ads7871_groups);
+       hwmon_dev = devm_hwmon_device_register_with_info(dev, spi->modalias,
+                                                        pdata,
+                                                        &ads7871_chip_info,
+                                                        NULL);
        return PTR_ERR_OR_ZERO(hwmon_dev);
 }