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path: root/drivers/hwmon/sht15.c
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Diffstat (limited to 'drivers/hwmon/sht15.c')
-rw-r--r--drivers/hwmon/sht15.c157
1 files changed, 99 insertions, 58 deletions
diff --git a/drivers/hwmon/sht15.c b/drivers/hwmon/sht15.c
index 1c85d39df171..bfe326e896df 100644
--- a/drivers/hwmon/sht15.c
+++ b/drivers/hwmon/sht15.c
@@ -139,12 +139,12 @@ static const u8 sht15_crc8_table[] = {
* @reg: associated regulator (if specified).
* @nb: notifier block to handle notifications of voltage
* changes.
- * @supply_uV: local copy of supply voltage used to allow use of
+ * @supply_uv: local copy of supply voltage used to allow use of
* regulator consumer if available.
- * @supply_uV_valid: indicates that an updated value has not yet been
+ * @supply_uv_valid: indicates that an updated value has not yet been
* obtained from the regulator and so any calculations
* based upon it will be invalid.
- * @update_supply_work: work struct that is used to update the supply_uV.
+ * @update_supply_work: work struct that is used to update the supply_uv.
* @interrupt_handled: flag used to indicate a handler has been scheduled.
*/
struct sht15_data {
@@ -166,8 +166,8 @@ struct sht15_data {
struct device *hwmon_dev;
struct regulator *reg;
struct notifier_block nb;
- int supply_uV;
- bool supply_uV_valid;
+ int supply_uv;
+ bool supply_uv_valid;
struct work_struct update_supply_work;
atomic_t interrupt_handled;
};
@@ -212,11 +212,13 @@ static u8 sht15_crc8(struct sht15_data *data,
*
* This implements section 3.4 of the data sheet
*/
-static void sht15_connection_reset(struct sht15_data *data)
+static int sht15_connection_reset(struct sht15_data *data)
{
- int i;
+ int i, err;
- gpio_direction_output(data->pdata->gpio_data, 1);
+ err = gpio_direction_output(data->pdata->gpio_data, 1);
+ if (err)
+ return err;
ndelay(SHT15_TSCKL);
gpio_set_value(data->pdata->gpio_sck, 0);
ndelay(SHT15_TSCKL);
@@ -226,6 +228,7 @@ static void sht15_connection_reset(struct sht15_data *data)
gpio_set_value(data->pdata->gpio_sck, 0);
ndelay(SHT15_TSCKL);
}
+ return 0;
}
/**
@@ -251,10 +254,14 @@ static inline void sht15_send_bit(struct sht15_data *data, int val)
* conservative ones used in implementation. This implements
* figure 12 on the data sheet.
*/
-static void sht15_transmission_start(struct sht15_data *data)
+static int sht15_transmission_start(struct sht15_data *data)
{
+ int err;
+
/* ensure data is high and output */
- gpio_direction_output(data->pdata->gpio_data, 1);
+ err = gpio_direction_output(data->pdata->gpio_data, 1);
+ if (err)
+ return err;
ndelay(SHT15_TSU);
gpio_set_value(data->pdata->gpio_sck, 0);
ndelay(SHT15_TSCKL);
@@ -270,6 +277,7 @@ static void sht15_transmission_start(struct sht15_data *data)
ndelay(SHT15_TSU);
gpio_set_value(data->pdata->gpio_sck, 0);
ndelay(SHT15_TSCKL);
+ return 0;
}
/**
@@ -293,13 +301,19 @@ static void sht15_send_byte(struct sht15_data *data, u8 byte)
*/
static int sht15_wait_for_response(struct sht15_data *data)
{
- gpio_direction_input(data->pdata->gpio_data);
+ int err;
+
+ err = gpio_direction_input(data->pdata->gpio_data);
+ if (err)
+ return err;
gpio_set_value(data->pdata->gpio_sck, 1);
ndelay(SHT15_TSCKH);
if (gpio_get_value(data->pdata->gpio_data)) {
gpio_set_value(data->pdata->gpio_sck, 0);
dev_err(data->dev, "Command not acknowledged\n");
- sht15_connection_reset(data);
+ err = sht15_connection_reset(data);
+ if (err)
+ return err;
return -EIO;
}
gpio_set_value(data->pdata->gpio_sck, 0);
@@ -317,12 +331,13 @@ static int sht15_wait_for_response(struct sht15_data *data)
*/
static int sht15_send_cmd(struct sht15_data *data, u8 cmd)
{
- int ret = 0;
+ int err;
- sht15_transmission_start(data);
+ err = sht15_transmission_start(data);
+ if (err)
+ return err;
sht15_send_byte(data, cmd);
- ret = sht15_wait_for_response(data);
- return ret;
+ return sht15_wait_for_response(data);
}
/**
@@ -352,9 +367,13 @@ static int sht15_soft_reset(struct sht15_data *data)
* Each byte of data is acknowledged by pulling the data line
* low for one clock pulse.
*/
-static void sht15_ack(struct sht15_data *data)
+static int sht15_ack(struct sht15_data *data)
{
- gpio_direction_output(data->pdata->gpio_data, 0);
+ int err;
+
+ err = gpio_direction_output(data->pdata->gpio_data, 0);
+ if (err)
+ return err;
ndelay(SHT15_TSU);
gpio_set_value(data->pdata->gpio_sck, 1);
ndelay(SHT15_TSU);
@@ -362,7 +381,7 @@ static void sht15_ack(struct sht15_data *data)
ndelay(SHT15_TSU);
gpio_set_value(data->pdata->gpio_data, 1);
- gpio_direction_input(data->pdata->gpio_data);
+ return gpio_direction_input(data->pdata->gpio_data);
}
/**
@@ -371,14 +390,19 @@ static void sht15_ack(struct sht15_data *data)
*
* This is basically a NAK (single clock pulse, data high).
*/
-static void sht15_end_transmission(struct sht15_data *data)
+static int sht15_end_transmission(struct sht15_data *data)
{
- gpio_direction_output(data->pdata->gpio_data, 1);
+ int err;
+
+ err = gpio_direction_output(data->pdata->gpio_data, 1);
+ if (err)
+ return err;
ndelay(SHT15_TSU);
gpio_set_value(data->pdata->gpio_sck, 1);
ndelay(SHT15_TSCKH);
gpio_set_value(data->pdata->gpio_sck, 0);
ndelay(SHT15_TSCKL);
+ return 0;
}
/**
@@ -410,17 +434,19 @@ static u8 sht15_read_byte(struct sht15_data *data)
*/
static int sht15_send_status(struct sht15_data *data, u8 status)
{
- int ret;
-
- ret = sht15_send_cmd(data, SHT15_WRITE_STATUS);
- if (ret)
- return ret;
- gpio_direction_output(data->pdata->gpio_data, 1);
+ int err;
+
+ err = sht15_send_cmd(data, SHT15_WRITE_STATUS);
+ if (err)
+ return err;
+ err = gpio_direction_output(data->pdata->gpio_data, 1);
+ if (err)
+ return err;
ndelay(SHT15_TSU);
sht15_send_byte(data, status);
- ret = sht15_wait_for_response(data);
- if (ret)
- return ret;
+ err = sht15_wait_for_response(data);
+ if (err)
+ return err;
data->val_status = status;
return 0;
@@ -446,7 +472,7 @@ static int sht15_update_status(struct sht15_data *data)
|| !data->status_valid) {
ret = sht15_send_cmd(data, SHT15_READ_STATUS);
if (ret)
- goto error_ret;
+ goto unlock;
status = sht15_read_byte(data);
if (data->checksumming) {
@@ -458,7 +484,9 @@ static int sht15_update_status(struct sht15_data *data)
== dev_checksum);
}
- sht15_end_transmission(data);
+ ret = sht15_end_transmission(data);
+ if (ret)
+ goto unlock;
/*
* Perform checksum validation on the received data.
@@ -469,27 +497,27 @@ static int sht15_update_status(struct sht15_data *data)
previous_config = data->val_status & 0x07;
ret = sht15_soft_reset(data);
if (ret)
- goto error_ret;
+ goto unlock;
if (previous_config) {
ret = sht15_send_status(data, previous_config);
if (ret) {
dev_err(data->dev,
"CRC validation failed, unable "
"to restore device settings\n");
- goto error_ret;
+ goto unlock;
}
}
ret = -EAGAIN;
- goto error_ret;
+ goto unlock;
}
data->val_status = status;
data->status_valid = true;
data->last_status = jiffies;
}
-error_ret:
- mutex_unlock(&data->read_lock);
+unlock:
+ mutex_unlock(&data->read_lock);
return ret;
}
@@ -511,7 +539,9 @@ static int sht15_measurement(struct sht15_data *data,
if (ret)
return ret;
- gpio_direction_input(data->pdata->gpio_data);
+ ret = gpio_direction_input(data->pdata->gpio_data);
+ if (ret)
+ return ret;
atomic_set(&data->interrupt_handled, 0);
enable_irq(gpio_to_irq(data->pdata->gpio_data));
@@ -524,9 +554,14 @@ static int sht15_measurement(struct sht15_data *data,
ret = wait_event_timeout(data->wait_queue,
(data->state == SHT15_READING_NOTHING),
msecs_to_jiffies(timeout_msecs));
- if (ret == 0) {/* timeout occurred */
+ if (data->state != SHT15_READING_NOTHING) { /* I/O error occurred */
+ data->state = SHT15_READING_NOTHING;
+ return -EIO;
+ } else if (ret == 0) { /* timeout occurred */
disable_irq_nosync(gpio_to_irq(data->pdata->gpio_data));
- sht15_connection_reset(data);
+ ret = sht15_connection_reset(data);
+ if (ret)
+ return ret;
return -ETIME;
}
@@ -570,17 +605,17 @@ static int sht15_update_measurements(struct sht15_data *data)
data->state = SHT15_READING_HUMID;
ret = sht15_measurement(data, SHT15_MEASURE_RH, 160);
if (ret)
- goto error_ret;
+ goto unlock;
data->state = SHT15_READING_TEMP;
ret = sht15_measurement(data, SHT15_MEASURE_TEMP, 400);
if (ret)
- goto error_ret;
+ goto unlock;
data->measurements_valid = true;
data->last_measurement = jiffies;
}
-error_ret:
- mutex_unlock(&data->read_lock);
+unlock:
+ mutex_unlock(&data->read_lock);
return ret;
}
@@ -598,8 +633,8 @@ static inline int sht15_calc_temp(struct sht15_data *data)
for (i = ARRAY_SIZE(temppoints) - 1; i > 0; i--)
/* Find pointer to interpolate */
- if (data->supply_uV > temppoints[i - 1].vdd) {
- d1 = (data->supply_uV - temppoints[i - 1].vdd)
+ if (data->supply_uv > temppoints[i - 1].vdd) {
+ d1 = (data->supply_uv - temppoints[i - 1].vdd)
* (temppoints[i].d1 - temppoints[i - 1].d1)
/ (temppoints[i].vdd - temppoints[i - 1].vdd)
+ temppoints[i - 1].d1;
@@ -818,7 +853,8 @@ static void sht15_bh_read_data(struct work_struct *work_s)
/* Read the data back from the device */
val = sht15_read_byte(data);
val <<= 8;
- sht15_ack(data);
+ if (sht15_ack(data))
+ goto wakeup;
val |= sht15_read_byte(data);
if (data->checksumming) {
@@ -826,7 +862,8 @@ static void sht15_bh_read_data(struct work_struct *work_s)
* Ask the device for a checksum and read it back.
* Note: the device sends the checksum byte reversed.
*/
- sht15_ack(data);
+ if (sht15_ack(data))
+ goto wakeup;
dev_checksum = sht15_reverse(sht15_read_byte(data));
checksum_vals[0] = (data->state == SHT15_READING_TEMP) ?
SHT15_MEASURE_TEMP : SHT15_MEASURE_RH;
@@ -837,7 +874,8 @@ static void sht15_bh_read_data(struct work_struct *work_s)
}
/* Tell the device we are done */
- sht15_end_transmission(data);
+ if (sht15_end_transmission(data))
+ goto wakeup;
switch (data->state) {
case SHT15_READING_TEMP:
@@ -851,6 +889,7 @@ static void sht15_bh_read_data(struct work_struct *work_s)
}
data->state = SHT15_READING_NOTHING;
+wakeup:
wake_up(&data->wait_queue);
}
@@ -859,7 +898,7 @@ static void sht15_update_voltage(struct work_struct *work_s)
struct sht15_data *data
= container_of(work_s, struct sht15_data,
update_supply_work);
- data->supply_uV = regulator_get_voltage(data->reg);
+ data->supply_uv = regulator_get_voltage(data->reg);
}
/**
@@ -878,7 +917,7 @@ static int sht15_invalidate_voltage(struct notifier_block *nb,
struct sht15_data *data = container_of(nb, struct sht15_data, nb);
if (event == REGULATOR_EVENT_VOLTAGE_CHANGE)
- data->supply_uV_valid = false;
+ data->supply_uv_valid = false;
schedule_work(&data->update_supply_work);
return NOTIFY_OK;
@@ -906,7 +945,7 @@ static int sht15_probe(struct platform_device *pdev)
return -EINVAL;
}
data->pdata = pdev->dev.platform_data;
- data->supply_uV = data->pdata->supply_mv * 1000;
+ data->supply_uv = data->pdata->supply_mv * 1000;
if (data->pdata->checksum)
data->checksumming = true;
if (data->pdata->no_otp_reload)
@@ -924,7 +963,7 @@ static int sht15_probe(struct platform_device *pdev)
voltage = regulator_get_voltage(data->reg);
if (voltage)
- data->supply_uV = voltage;
+ data->supply_uv = voltage;
regulator_enable(data->reg);
/*
@@ -942,17 +981,17 @@ static int sht15_probe(struct platform_device *pdev)
}
/* Try requesting the GPIOs */
- ret = devm_gpio_request(&pdev->dev, data->pdata->gpio_sck, "SHT15 sck");
+ ret = devm_gpio_request_one(&pdev->dev, data->pdata->gpio_sck,
+ GPIOF_OUT_INIT_LOW, "SHT15 sck");
if (ret) {
- dev_err(&pdev->dev, "gpio request failed\n");
+ dev_err(&pdev->dev, "clock line GPIO request failed\n");
goto err_release_reg;
}
- gpio_direction_output(data->pdata->gpio_sck, 0);
ret = devm_gpio_request(&pdev->dev, data->pdata->gpio_data,
"SHT15 data");
if (ret) {
- dev_err(&pdev->dev, "gpio request failed\n");
+ dev_err(&pdev->dev, "data line GPIO request failed\n");
goto err_release_reg;
}
@@ -966,7 +1005,9 @@ static int sht15_probe(struct platform_device *pdev)
goto err_release_reg;
}
disable_irq_nosync(gpio_to_irq(data->pdata->gpio_data));
- sht15_connection_reset(data);
+ ret = sht15_connection_reset(data);
+ if (ret)
+ goto err_release_reg;
ret = sht15_soft_reset(data);
if (ret)
goto err_release_reg;
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-08 01:17:17 +0300