drivers: w1: add hwmon temp support for w1_therm

This change adds hwmon temp support for w1_therm.

Signed-off-by: Jaghathiswari Rankappagounder Natarajan <jaghu@google.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/w1/slaves/w1_therm.c b/drivers/w1/slaves/w1_therm.c
index faddc24..259525c 100644 (file)
--- a/drivers/w1/slaves/w1_therm.c
+++ b/drivers/w1/slaves/w1_therm.c
@@ -29,6 +29,7 @@
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
+#include <linux/hwmon.h>
 
 #include <linux/w1.h>
 
@@ -113,19 +114,72 @@ static struct attribute *w1_ds28ea00_attrs[] = {
        &dev_attr_w1_seq.attr,
        NULL,
 };
+
 ATTRIBUTE_GROUPS(w1_therm);
 ATTRIBUTE_GROUPS(w1_ds28ea00);
 
+#if IS_REACHABLE(CONFIG_HWMON)
+static int w1_read_temp(struct device *dev, u32 attr, int channel,
+                       long *val);
+
+static umode_t w1_is_visible(const void *_data, enum hwmon_sensor_types type,
+                            u32 attr, int channel)
+{
+       return attr == hwmon_temp_input ? 0444 : 0;
+}
+
+static int w1_read(struct device *dev, enum hwmon_sensor_types type,
+                  u32 attr, int channel, long *val)
+{
+       switch (type) {
+       case hwmon_temp:
+               return w1_read_temp(dev, attr, channel, val);
+       default:
+               return -EOPNOTSUPP;
+       }
+}
+
+static const u32 w1_temp_config[] = {
+       HWMON_T_INPUT,
+       0
+};
+
+static const struct hwmon_channel_info w1_temp = {
+       .type = hwmon_temp,
+       .config = w1_temp_config,
+};
+
+static const struct hwmon_channel_info *w1_info[] = {
+       &w1_temp,
+       NULL
+};
+
+static const struct hwmon_ops w1_hwmon_ops = {
+       .is_visible = w1_is_visible,
+       .read = w1_read,
+};
+
+static const struct hwmon_chip_info w1_chip_info = {
+       .ops = &w1_hwmon_ops,
+       .info = w1_info,
+};
+#define W1_CHIPINFO    (&w1_chip_info)
+#else
+#define W1_CHIPINFO    NULL
+#endif
+
 static struct w1_family_ops w1_therm_fops = {
        .add_slave      = w1_therm_add_slave,
        .remove_slave   = w1_therm_remove_slave,
        .groups         = w1_therm_groups,
+       .chip_info      = W1_CHIPINFO,
 };
 
 static struct w1_family_ops w1_ds28ea00_fops = {
        .add_slave      = w1_therm_add_slave,
        .remove_slave   = w1_therm_remove_slave,
        .groups         = w1_ds28ea00_groups,
+       .chip_info      = W1_CHIPINFO,
 };
 
 static struct w1_family w1_therm_family_DS18S20 = {
@@ -554,6 +608,38 @@ static ssize_t w1_slave_show(struct device *device,
        return ret;
 }
 
+#if IS_REACHABLE(CONFIG_HWMON)
+static int w1_read_temp(struct device *device, u32 attr, int channel,
+                       long *val)
+{
+       struct w1_slave *sl = dev_get_drvdata(device);
+       struct therm_info info;
+       u8 fid = sl->family->fid;
+       int ret;
+
+       switch (attr) {
+       case hwmon_temp_input:
+               ret = read_therm(device, sl, &info);
+               if (ret)
+                       return ret;
+
+               if (!info.verdict) {
+                       ret = -EIO;
+                       return ret;
+               }
+
+               *val = w1_convert_temp(info.rom, fid);
+               ret = 0;
+               break;
+       default:
+               ret = -EOPNOTSUPP;
+               break;
+       }
+
+       return ret;
+}
+#endif
+
 #define W1_42_CHAIN    0x99
 #define W1_42_CHAIN_OFF        0x3C
 #define W1_42_CHAIN_OFF_INV    0xC3