From 45034e48276c310bf4d4c7d7110169756d4a6265 Mon Sep 17 00:00:00 2001 From: Brandon Maier Date: Thu, 7 Feb 2019 15:50:36 -0600 Subject: hwmon: (ad7418) Catch I2C errors If there is an i2c failure, the ad7416 reports its temperature as 0C. Return an error code so users can properly detect errors. Signed-off-by: Brandon Maier Signed-off-by: Guenter Roeck --- drivers/hwmon/ad7418.c | 63 ++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 48 insertions(+), 15 deletions(-) (limited to 'drivers/hwmon') diff --git a/drivers/hwmon/ad7418.c b/drivers/hwmon/ad7418.c index 76f0a5c01e8a..a20d5ebe9d97 100644 --- a/drivers/hwmon/ad7418.c +++ b/drivers/hwmon/ad7418.c @@ -54,10 +54,11 @@ struct ad7418_data { u16 in[4]; }; -static struct ad7418_data *ad7418_update_device(struct device *dev) +static int ad7418_update_device(struct device *dev) { struct ad7418_data *data = dev_get_drvdata(dev); struct i2c_client *client = data->client; + s32 val; mutex_lock(&data->lock); @@ -67,47 +68,74 @@ static struct ad7418_data *ad7418_update_device(struct device *dev) int i, ch; /* read config register and clear channel bits */ - cfg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF); + val = i2c_smbus_read_byte_data(client, AD7418_REG_CONF); + if (val < 0) + goto abort; + + cfg = val; cfg &= 0x1F; - i2c_smbus_write_byte_data(client, AD7418_REG_CONF, + val = i2c_smbus_write_byte_data(client, AD7418_REG_CONF, cfg | AD7418_CH_TEMP); + if (val < 0) + goto abort; + udelay(30); for (i = 0; i < 3; i++) { - data->temp[i] = - i2c_smbus_read_word_swapped(client, - AD7418_REG_TEMP[i]); + val = i2c_smbus_read_word_swapped(client, + AD7418_REG_TEMP[i]); + if (val < 0) + goto abort; + + data->temp[i] = val; } for (i = 0, ch = 4; i < data->adc_max; i++, ch--) { - i2c_smbus_write_byte_data(client, - AD7418_REG_CONF, + val = i2c_smbus_write_byte_data(client, AD7418_REG_CONF, cfg | AD7418_REG_ADC_CH(ch)); + if (val < 0) + goto abort; udelay(15); - data->in[data->adc_max - 1 - i] = - i2c_smbus_read_word_swapped(client, - AD7418_REG_ADC); + val = i2c_smbus_read_word_swapped(client, + AD7418_REG_ADC); + if (val < 0) + goto abort; + + data->in[data->adc_max - 1 - i] = val; } /* restore old configuration value */ - i2c_smbus_write_word_swapped(client, AD7418_REG_CONF, cfg); + val = i2c_smbus_write_word_swapped(client, AD7418_REG_CONF, + cfg); + if (val < 0) + goto abort; data->last_updated = jiffies; data->valid = 1; } mutex_unlock(&data->lock); + return 0; - return data; +abort: + data->valid = 0; + mutex_unlock(&data->lock); + return val; } static ssize_t temp_show(struct device *dev, struct device_attribute *devattr, char *buf) { struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); - struct ad7418_data *data = ad7418_update_device(dev); + struct ad7418_data *data = dev_get_drvdata(dev); + int ret; + + ret = ad7418_update_device(dev); + if (ret < 0) + return ret; + return sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(data->temp[attr->index])); } @@ -116,7 +144,12 @@ static ssize_t adc_show(struct device *dev, struct device_attribute *devattr, char *buf) { struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); - struct ad7418_data *data = ad7418_update_device(dev); + struct ad7418_data *data = dev_get_drvdata(dev); + int ret; + + ret = ad7418_update_device(dev); + if (ret < 0) + return ret; return sprintf(buf, "%d\n", ((data->in[attr->index] >> 6) * 2500 + 512) / 1024); -- cgit