Re: [PATCH v2] hwmon: adt7411: add min, max and alarm attributes

From: Guenter Roeck
Date: Fri Dec 02 2016 - 10:23:59 EST


Hi Michael,

On 12/02/2016 06:26 AM, Michael Walle wrote:
This patch adds support for the min, max and alarm attributes of the
voltage and temperature channels. Additionally, the temp2_fault attribute
is supported which indicates a fault of the external temperature diode.

Signed-off-by: Michael Walle <michael@xxxxxxxx>

Mostly looks good, except for a couple of overflow issues.

Thanks,
Guenter

---
v2:
- use BIT()
- new function adt7411_write_in_vdd()
- add missing "return 0" in read_in_vdd() for hwmon_in_max
- add missing "default" case in read_temp_alarm()
- remove uneeded "val + 0x100" statement
- fix AIN2 visibility

drivers/hwmon/adt7411.c | 361 ++++++++++++++++++++++++++++++++++++++++++------
1 file changed, 316 insertions(+), 45 deletions(-)

diff --git a/drivers/hwmon/adt7411.c b/drivers/hwmon/adt7411.c
index 2f44cdc..37e3b96 100644
--- a/drivers/hwmon/adt7411.c
+++ b/drivers/hwmon/adt7411.c
@@ -21,6 +21,21 @@
#include <linux/hwmon-sysfs.h>
#include <linux/slab.h>

+#define ADT7411_REG_STAT_1 0x00
+#define ADT7411_STAT_1_INT_TEMP_HIGH BIT(0)
+#define ADT7411_STAT_1_INT_TEMP_LOW BIT(1)
+#define ADT7411_STAT_1_EXT_TEMP_HIGH_AIN1 BIT(2)
+#define ADT7411_STAT_1_EXT_TEMP_LOW BIT(3)
+#define ADT7411_STAT_1_EXT_TEMP_FAULT BIT(4)
+#define ADT7411_STAT_1_AIN2 BIT(5)
+#define ADT7411_STAT_1_AIN3 BIT(6)
+#define ADT7411_STAT_1_AIN4 BIT(7)
+#define ADT7411_REG_STAT_2 0x01
+#define ADT7411_STAT_2_AIN5 BIT(0)
+#define ADT7411_STAT_2_AIN6 BIT(1)
+#define ADT7411_STAT_2_AIN7 BIT(2)
+#define ADT7411_STAT_2_AIN8 BIT(3)
+#define ADT7411_STAT_2_VDD BIT(4)
#define ADT7411_REG_INT_TEMP_VDD_LSB 0x03
#define ADT7411_REG_EXT_TEMP_AIN14_LSB 0x04
#define ADT7411_REG_VDD_MSB 0x06
@@ -28,20 +43,31 @@
#define ADT7411_REG_EXT_TEMP_AIN1_MSB 0x08

#define ADT7411_REG_CFG1 0x18
-#define ADT7411_CFG1_START_MONITOR (1 << 0)
-#define ADT7411_CFG1_RESERVED_BIT1 (1 << 1)
-#define ADT7411_CFG1_EXT_TDM (1 << 2)
-#define ADT7411_CFG1_RESERVED_BIT3 (1 << 3)
+#define ADT7411_CFG1_START_MONITOR BIT(0)
+#define ADT7411_CFG1_RESERVED_BIT1 BIT(1)
+#define ADT7411_CFG1_EXT_TDM BIT(2)
+#define ADT7411_CFG1_RESERVED_BIT3 BIT(3)

#define ADT7411_REG_CFG2 0x19
-#define ADT7411_CFG2_DISABLE_AVG (1 << 5)
+#define ADT7411_CFG2_DISABLE_AVG BIT(5)

#define ADT7411_REG_CFG3 0x1a
-#define ADT7411_CFG3_ADC_CLK_225 (1 << 0)
-#define ADT7411_CFG3_RESERVED_BIT1 (1 << 1)
-#define ADT7411_CFG3_RESERVED_BIT2 (1 << 2)
-#define ADT7411_CFG3_RESERVED_BIT3 (1 << 3)
-#define ADT7411_CFG3_REF_VDD (1 << 4)
+#define ADT7411_CFG3_ADC_CLK_225 BIT(0)
+#define ADT7411_CFG3_RESERVED_BIT1 BIT(1)
+#define ADT7411_CFG3_RESERVED_BIT2 BIT(2)
+#define ADT7411_CFG3_RESERVED_BIT3 BIT(3)
+#define ADT7411_CFG3_REF_VDD BIT(4)
+
+#define ADT7411_REG_VDD_HIGH 0x23
+#define ADT7411_REG_VDD_LOW 0x24
+#define ADT7411_REG_TEMP_HIGH(nr) (0x25 + 2 * (nr))
+#define ADT7411_REG_TEMP_LOW(nr) (0x26 + 2 * (nr))
+#define ADT7411_REG_IN_HIGH(nr) ((nr) > 1 \
+ ? 0x2b + 2 * ((nr)-2) \
+ : 0x27)
+#define ADT7411_REG_IN_LOW(nr) ((nr) > 1 \
+ ? 0x2c + 2 * ((nr)-2) \
+ : 0x28)

#define ADT7411_REG_DEVICE_ID 0x4d
#define ADT7411_REG_MANUFACTURER_ID 0x4e
@@ -51,6 +77,30 @@

static const unsigned short normal_i2c[] = { 0x48, 0x4a, 0x4b, I2C_CLIENT_END };

+static const u8 adt7411_in_alarm_reg[] = {
+ ADT7411_REG_STAT_2,
+ ADT7411_REG_STAT_1,
+ ADT7411_REG_STAT_1,
+ ADT7411_REG_STAT_1,
+ ADT7411_REG_STAT_1,
+ ADT7411_REG_STAT_2,
+ ADT7411_REG_STAT_2,
+ ADT7411_REG_STAT_2,
+ ADT7411_REG_STAT_2,
+};
+
+static const u8 adt7411_in_alarm_bits[] = {
+ ADT7411_STAT_2_VDD,
+ ADT7411_STAT_1_EXT_TEMP_HIGH_AIN1,
+ ADT7411_STAT_1_AIN2,
+ ADT7411_STAT_1_AIN3,
+ ADT7411_STAT_1_AIN4,
+ ADT7411_STAT_2_AIN5,
+ ADT7411_STAT_2_AIN6,
+ ADT7411_STAT_2_AIN7,
+ ADT7411_STAT_2_AIN8,
+};
+
struct adt7411_data {
struct mutex device_lock; /* for "atomic" device accesses */
struct mutex update_lock;
@@ -165,6 +215,19 @@ static struct attribute *adt7411_attrs[] = {
};
ATTRIBUTE_GROUPS(adt7411);

+static int adt7411_read_in_alarm(struct device *dev, int channel, long *val)
+{
+ struct adt7411_data *data = dev_get_drvdata(dev);
+ struct i2c_client *client = data->client;
+ int ret;
+
+ ret = i2c_smbus_read_byte_data(client, adt7411_in_alarm_reg[channel]);
+ if (ret < 0)
+ return ret;
+ *val = !!(ret & adt7411_in_alarm_bits[channel]);
+ return 0;
+}
+
static int adt7411_read_in_vdd(struct device *dev, u32 attr, long *val)
{
struct adt7411_data *data = dev_get_drvdata(dev);
@@ -179,32 +242,41 @@ static int adt7411_read_in_vdd(struct device *dev, u32 attr, long *val)
return ret;
*val = ret * 7000 / 1024;
return 0;
+ case hwmon_in_min:
+ ret = i2c_smbus_read_byte_data(client, ADT7411_REG_VDD_LOW);
+ if (ret < 0)
+ return ret;
+ *val = ret * 7000 / 256;
+ return 0;
+ case hwmon_in_max:
+ ret = i2c_smbus_read_byte_data(client, ADT7411_REG_VDD_HIGH);
+ if (ret < 0)
+ return ret;
+ *val = ret * 7000 / 256;
+ return 0;
+ case hwmon_in_alarm:
+ return adt7411_read_in_alarm(dev, 0, val);
default:
return -EOPNOTSUPP;
}
}

-static int adt7411_read_in_chan(struct device *dev, u32 attr, int channel,
- long *val)
+static int adt7411_update_vref(struct device *dev)
{
struct adt7411_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
+ int val;

- int ret;
- int lsb_reg, lsb_shift;
- int nr = channel - 1;
-
- mutex_lock(&data->update_lock);
if (time_after_eq(jiffies, data->next_update)) {
- ret = i2c_smbus_read_byte_data(client, ADT7411_REG_CFG3);
- if (ret < 0)
- goto exit_unlock;
+ val = i2c_smbus_read_byte_data(client, ADT7411_REG_CFG3);
+ if (val < 0)
+ return val;

- if (ret & ADT7411_CFG3_REF_VDD) {
- ret = adt7411_read_in_vdd(dev, hwmon_in_input,
+ if (val & ADT7411_CFG3_REF_VDD) {
+ val = adt7411_read_in_vdd(dev, hwmon_in_input,
&data->vref_cached);
- if (ret < 0)
- goto exit_unlock;
+ if (val < 0)
+ return val;
} else {
data->vref_cached = 2250;
}
@@ -212,6 +284,24 @@ static int adt7411_read_in_chan(struct device *dev, u32 attr, int channel,
data->next_update = jiffies + HZ;
}

+ return 0;
+}
+
+static int adt7411_read_in_chan(struct device *dev, u32 attr, int channel,
+ long *val)
+{
+ struct adt7411_data *data = dev_get_drvdata(dev);
+ struct i2c_client *client = data->client;
+
+ int ret;
+ int reg, lsb_reg, lsb_shift;
+ int nr = channel - 1;
+
+ mutex_lock(&data->update_lock);
+ ret = adt7411_update_vref(dev);
+ if (ret < 0)
+ goto exit_unlock;
+
switch (attr) {
case hwmon_in_input:
lsb_reg = ADT7411_REG_EXT_TEMP_AIN14_LSB + (nr >> 2);
@@ -223,6 +313,20 @@ static int adt7411_read_in_chan(struct device *dev, u32 attr, int channel,
*val = ret * data->vref_cached / 1024;
ret = 0;
break;
+ case hwmon_in_min:
+ case hwmon_in_max:
+ reg = (attr == hwmon_in_min)
+ ? ADT7411_REG_IN_LOW(channel)
+ : ADT7411_REG_IN_HIGH(channel);
+ ret = i2c_smbus_read_byte_data(client, reg);
+ if (ret < 0)
+ goto exit_unlock;
+ *val = ret * data->vref_cached / 256;
+ ret = 0;
+ break;
+ case hwmon_in_alarm:
+ ret = adt7411_read_in_alarm(dev, channel, val);
+ break;
default:
ret = -EOPNOTSUPP;
break;
@@ -241,12 +345,44 @@ static int adt7411_read_in(struct device *dev, u32 attr, int channel,
return adt7411_read_in_chan(dev, attr, channel, val);
}

+
+static int adt7411_read_temp_alarm(struct device *dev, u32 attr, int channel,
+ long *val)
+{
+ struct adt7411_data *data = dev_get_drvdata(dev);
+ struct i2c_client *client = data->client;
+ int ret, bit;
+
+ ret = i2c_smbus_read_byte_data(client, ADT7411_REG_STAT_1);
+ if (ret < 0)
+ return ret;
+
+ switch (attr) {
+ case hwmon_temp_min_alarm:
+ bit = channel ? ADT7411_STAT_1_EXT_TEMP_LOW
+ : ADT7411_STAT_1_INT_TEMP_LOW;
+ break;
+ case hwmon_temp_max_alarm:
+ bit = channel ? ADT7411_STAT_1_EXT_TEMP_HIGH_AIN1
+ : ADT7411_STAT_1_INT_TEMP_HIGH;
+ break;
+ case hwmon_temp_fault:
+ bit = ADT7411_STAT_1_EXT_TEMP_FAULT;
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ *val = !!(ret & bit);
+ return 0;
+}
+
static int adt7411_read_temp(struct device *dev, u32 attr, int channel,
long *val)
{
struct adt7411_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
- int ret, regl, regh;
+ int ret, reg, regl, regh;

switch (attr) {
case hwmon_temp_input:
@@ -260,6 +396,21 @@ static int adt7411_read_temp(struct device *dev, u32 attr, int channel,
ret = ret & 0x200 ? ret - 0x400 : ret; /* 10 bit signed */
*val = ret * 250;
return 0;
+ case hwmon_temp_min:
+ case hwmon_temp_max:
+ reg = (attr == hwmon_temp_min)
+ ? ADT7411_REG_TEMP_LOW(channel)
+ : ADT7411_REG_TEMP_HIGH(channel);
+ ret = i2c_smbus_read_byte_data(client, reg);
+ if (ret < 0)
+ return ret;
+ ret = ret & 0x80 ? ret - 0x100 : ret; /* 8 bit signed */
+ *val = ret * 1000;
+ return 0;
+ case hwmon_temp_min_alarm:
+ case hwmon_temp_max_alarm:
+ case hwmon_temp_fault:
+ return adt7411_read_temp_alarm(dev, attr, channel, val);
default:
return -EOPNOTSUPP;
}
@@ -278,26 +429,143 @@ static int adt7411_read(struct device *dev, enum hwmon_sensor_types type,
}
}

+static int adt7411_write_in_vdd(struct device *dev, u32 attr, long val)
+{
+ struct adt7411_data *data = dev_get_drvdata(dev);
+ struct i2c_client *client = data->client;
+ int reg;
+
+ val = DIV_ROUND_CLOSEST(val * 256, 7000);

Causes overflow. You have to clamp before the DIV_ROUND_CLOSEST().

+ val = clamp_val(val, 0, 255);
+
+ switch (attr) {
+ case hwmon_in_min:
+ reg = ADT7411_REG_VDD_LOW;
+ break;
+ case hwmon_in_max:
+ reg = ADT7411_REG_VDD_HIGH;
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return i2c_smbus_write_byte_data(client, reg, val);
+}
+
+static int adt7411_write_in_chan(struct device *dev, u32 attr, int channel,
+ long val)
+{
+ struct adt7411_data *data = dev_get_drvdata(dev);
+ struct i2c_client *client = data->client;
+ int ret, reg;
+
+ mutex_lock(&data->update_lock);
+ ret = adt7411_update_vref(dev);
+ if (ret < 0)
+ goto exit_unlock;
+ val = DIV_ROUND_CLOSEST(val * 256, data->vref_cached);

Same as before.

+ val = clamp_val(val, 0, 255);
+
+ switch (attr) {
+ case hwmon_in_min:
+ reg = ADT7411_REG_IN_LOW(channel);
+ break;
+ case hwmon_in_max:
+ reg = ADT7411_REG_IN_HIGH(channel);
+ break;
+ default:
+ ret = -EOPNOTSUPP;
+ goto exit_unlock;
+ }
+
+ ret = i2c_smbus_write_byte_data(client, reg, val);
+ exit_unlock:
+ mutex_unlock(&data->update_lock);
+ return ret;
+}
+
+static int adt7411_write_in(struct device *dev, u32 attr, int channel,
+ long val)
+{
+ if (channel == 0)
+ return adt7411_write_in_vdd(dev, attr, val);
+ else
+ return adt7411_write_in_chan(dev, attr, channel, val);
+}
+
+static int adt7411_write_temp(struct device *dev, u32 attr, int channel,
+ long val)
+{
+ struct adt7411_data *data = dev_get_drvdata(dev);
+ struct i2c_client *client = data->client;
+ int reg;
+
+ val = DIV_ROUND_CLOSEST(val, 1000);

Same as before (DIV_ROUND_CLOSEST() needs to add to val for rounding).
Try writing MAX_LONG (9223372036854775807) and you'll see.

+ val = clamp_val(val, -128, 127);
+
+ switch (attr) {
+ case hwmon_temp_min:
+ reg = ADT7411_REG_TEMP_LOW(channel);
+ break;
+ case hwmon_temp_max:
+ reg = ADT7411_REG_TEMP_HIGH(channel);
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return i2c_smbus_write_byte_data(client, reg, val);
+}
+
+static int adt7411_write(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long val)
+{
+ switch (type) {
+ case hwmon_in:
+ return adt7411_write_in(dev, attr, channel, val);
+ case hwmon_temp:
+ return adt7411_write_temp(dev, attr, channel, val);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
static umode_t adt7411_is_visible(const void *_data,
enum hwmon_sensor_types type,
u32 attr, int channel)
{
const struct adt7411_data *data = _data;
+ bool visible;

switch (type) {
case hwmon_in:
- if (channel > 0 && channel < 3)
- return data->use_ext_temp ? 0 : S_IRUGO;
- else
- return S_IRUGO;
+ visible = channel == 0 || channel >= 3 || !data->use_ext_temp;
+ switch (attr) {
+ case hwmon_in_input:
+ case hwmon_in_alarm:
+ return visible ? S_IRUGO : 0;
+ case hwmon_in_min:
+ case hwmon_in_max:
+ return visible ? S_IRUGO | S_IWUSR : 0;
+ }
+ break;
case hwmon_temp:
- if (channel == 1)
- return data->use_ext_temp ? S_IRUGO : 0;
- else
- return S_IRUGO;
+ visible = channel == 0 || data->use_ext_temp;
+ switch (attr) {
+ case hwmon_temp_input:
+ case hwmon_temp_min_alarm:
+ case hwmon_temp_max_alarm:
+ case hwmon_temp_fault:
+ return visible ? S_IRUGO : 0;
+ case hwmon_temp_min:
+ case hwmon_temp_max:
+ return visible ? S_IRUGO | S_IWUSR : 0;
+ }
+ break;
default:
- return 0;
+ break;
}
+ return 0;
}

static int adt7411_detect(struct i2c_client *client,
@@ -371,15 +639,15 @@ static int adt7411_init_device(struct adt7411_data *data)
}

static const u32 adt7411_in_config[] = {
- HWMON_I_INPUT,
- HWMON_I_INPUT,
- HWMON_I_INPUT,
- HWMON_I_INPUT,
- HWMON_I_INPUT,
- HWMON_I_INPUT,
- HWMON_I_INPUT,
- HWMON_I_INPUT,
- HWMON_I_INPUT,
+ HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
+ HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
+ HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
+ HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
+ HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
+ HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
+ HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
+ HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
+ HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
0
};

@@ -389,8 +657,10 @@ static const struct hwmon_channel_info adt7411_in = {
};

static const u32 adt7411_temp_config[] = {
- HWMON_T_INPUT,
- HWMON_T_INPUT,
+ HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MIN_ALARM |
+ HWMON_T_MAX | HWMON_T_MAX_ALARM,
+ HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MIN_ALARM |
+ HWMON_T_MAX | HWMON_T_MAX_ALARM | HWMON_T_FAULT,
0
};

@@ -408,6 +678,7 @@ static const struct hwmon_channel_info *adt7411_info[] = {
static const struct hwmon_ops adt7411_hwmon_ops = {
.is_visible = adt7411_is_visible,
.read = adt7411_read,
+ .write = adt7411_write,
};

static const struct hwmon_chip_info adt7411_chip_info = {