hwmon: (sht15) clean-up the probe function

* Move the creation of sysfs attributes after the end of the
  initialization, and remove them in the error path.
* Release regulator in the error path.
* Add a soft reset command (need to wait 11ms before next command).

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>

1 files changed, 46 insertions, 8 deletions

diff --git a/drivers/hwmon/sht15.c b/drivers/hwmon/sht15.c
index 080af75c517b..3182b3f578e2 100644
--- a/drivers/hwmon/sht15.c
+++ b/drivers/hwmon/sht15.c
@@ -33,11 +33,13 @@
 /* Commands */
 #define SHT15_MEASURE_TEMP              0x03
 #define SHT15_MEASURE_RH                0x05
+#define SHT15_SOFT_RESET                0x1E
 
 /* Min timings */
 #define SHT15_TSCKL                     100     /* (nsecs) clock low */
 #define SHT15_TSCKH                     100     /* (nsecs) clock high */
 #define SHT15_TSU                       150     /* (nsecs) data setup time */
+#define SHT15_TSRST                     11      /* (msecs) soft reset time */
 
 /* Actions the driver may be doing */
 enum sht15_state {
@@ -229,6 +231,24 @@ static int sht15_send_cmd(struct sht15_data *data, u8 cmd)
 }
 
 /**
+ * sht15_soft_reset() - send a soft reset command
+ * @data:       sht15 specific data.
+ *
+ * As described in section 3.2 of the datasheet.
+ */
+static int sht15_soft_reset(struct sht15_data *data)
+{
+        int ret;
+
+        ret = sht15_send_cmd(data, SHT15_SOFT_RESET);
+        if (ret)
+                return ret;
+        msleep(SHT15_TSRST);
+
+        return 0;
+}
+
+/**
  * sht15_measurement() - get a new value from device
  * @data:               device instance specific data
  * @command:            command sent to request value
@@ -588,13 +608,20 @@ static int __devinit sht15_probe(struct platform_device *pdev)
                  */
                 data->nb.notifier_call = &sht15_invalidate_voltage;
                 ret = regulator_register_notifier(data->reg, &data->nb);
+                if (ret) {
+                        dev_err(&pdev->dev,
+                                "regulator notifier request failed\n");
+                        regulator_disable(data->reg);
+                        regulator_put(data->reg);
+                        goto err_free_data;
+                }
         }
 
         /* Try requesting the GPIOs */
         ret = gpio_request(data->pdata->gpio_sck, "SHT15 sck");
         if (ret) {
                 dev_err(&pdev->dev, "gpio request failed\n");
-                goto err_free_data;
+                goto err_release_reg;
         }
         gpio_direction_output(data->pdata->gpio_sck, 0);
 
@@ -603,11 +630,6 @@ static int __devinit sht15_probe(struct platform_device *pdev)
                 dev_err(&pdev->dev, "gpio request failed\n");
                 goto err_release_gpio_sck;
         }
-        ret = sysfs_create_group(&pdev->dev.kobj, &sht15_attr_group);
-        if (ret) {
-                dev_err(&pdev->dev, "sysfs create failed");
-                goto err_release_gpio_data;
-        }
 
         ret = request_irq(gpio_to_irq(data->pdata->gpio_data),
                           sht15_interrupt_fired,
@@ -620,22 +642,38 @@ static int __devinit sht15_probe(struct platform_device *pdev)
         }
         disable_irq_nosync(gpio_to_irq(data->pdata->gpio_data));
         sht15_connection_reset(data);
-        sht15_send_cmd(data, 0x1E);
+        ret = sht15_soft_reset(data);
+        if (ret)
+                goto err_release_irq;
+
+        ret = sysfs_create_group(&pdev->dev.kobj, &sht15_attr_group);
+        if (ret) {
+                dev_err(&pdev->dev, "sysfs create failed\n");
+                goto err_release_irq;
+        }
 
         data->hwmon_dev = hwmon_device_register(data->dev);
         if (IS_ERR(data->hwmon_dev)) {
                 ret = PTR_ERR(data->hwmon_dev);
-                goto err_release_irq;
+                goto err_release_sysfs_group;
         }
 
         return 0;
 
+err_release_sysfs_group:
+        sysfs_remove_group(&pdev->dev.kobj, &sht15_attr_group);
 err_release_irq:
         free_irq(gpio_to_irq(data->pdata->gpio_data), data);
 err_release_gpio_data:
         gpio_free(data->pdata->gpio_data);
 err_release_gpio_sck:
         gpio_free(data->pdata->gpio_sck);
+err_release_reg:
+        if (!IS_ERR(data->reg)) {
+                regulator_unregister_notifier(data->reg, &data->nb);
+                regulator_disable(data->reg);
+                regulator_put(data->reg);
+        }
 err_free_data:
         kfree(data);
 error_ret: