[lm-sensors] [PATCH v2 2/4] hwmon: (sht15) clean-up the probe function

Vivien Didelot vivien.didelot at savoirfairelinux.com
Tue Apr 12 21:34:37 CEST 2011


* 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 at savoirfairelinux.com>
---
 drivers/hwmon/sht15.c |   54 +++++++++++++++++++++++++++++++++++++++++-------
 1 files changed, 46 insertions(+), 8 deletions(-)

diff --git a/drivers/hwmon/sht15.c b/drivers/hwmon/sht15.c
index 5fd880d..42992fe 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:
-- 
1.7.1





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