* [PATCH] hwmon: adm1275: Make sure we are reading enough data for different chips
@ 2020-07-08 23:53 Chu Lin
2020-07-09 0:33 ` Guenter Roeck
0 siblings, 1 reply; 4+ messages in thread
From: Chu Lin @ 2020-07-08 23:53 UTC (permalink / raw)
To: linux
Cc: belgaied, jasonling, jdelvare, linchuyuan, linux-hwmon,
linux-kernel, zhongqil
Issue:
When binding adm1272 to the adm1275 driver, PEC error is reported.
See blow:
adm1275: probe of xxxx failed with error -74
Diagnosis:
Per the datasheet of adm1272 and adm1278 (www.analog.com),
PMON_CONFIG (0xd4) is 16bits wide. On the other hand,
PMON_CONFIG (0xd4) for adm1275 is 8bits wide.
The driver should not assume everything is 8bits wide and read only
8bits from it.
Solution:
if it is adm1272 or adm1278, use i2c_read_word. Else, use i2c_read_byte
Signed-off-by: Chu Lin <linchuyuan@google.com>
---
drivers/hwmon/pmbus/adm1275.c | 24 ++++++++++++++++--------
1 file changed, 16 insertions(+), 8 deletions(-)
diff --git a/drivers/hwmon/pmbus/adm1275.c b/drivers/hwmon/pmbus/adm1275.c
index e25f541227da..a0d547d20358 100644
--- a/drivers/hwmon/pmbus/adm1275.c
+++ b/drivers/hwmon/pmbus/adm1275.c
@@ -472,6 +472,7 @@ static int adm1275_probe(struct i2c_client *client,
struct adm1275_data *data;
const struct i2c_device_id *mid;
const struct coefficients *coefficients;
+ s32 (*config_read_fn_ptr)(const struct i2c_client *client, u8 reg);
int vindex = -1, voindex = -1, cindex = -1, pindex = -1;
int tindex = -1;
u32 shunt;
@@ -510,14 +511,6 @@ static int adm1275_probe(struct i2c_client *client,
"Device mismatch: Configured %s, detected %s\n",
id->name, mid->name);
- config = i2c_smbus_read_byte_data(client, ADM1275_PMON_CONFIG);
- if (config < 0)
- return config;
-
- device_config = i2c_smbus_read_byte_data(client, ADM1275_DEVICE_CONFIG);
- if (device_config < 0)
- return device_config;
-
data = devm_kzalloc(&client->dev, sizeof(struct adm1275_data),
GFP_KERNEL);
if (!data)
@@ -532,6 +525,21 @@ static int adm1275_probe(struct i2c_client *client,
data->id = mid->driver_data;
+ /* adm1272 and adm1278 supports temperature monitoring. The config and device config
+ * are 16bits wide for these two devices. On the other hand, other devices are 8 bits wide
+ */
+ if (data->id == adm1272 || data->id == adm1278)
+ config_read_fn_ptr = &i2c_smbus_read_word_data;
+ else
+ config_read_fn_ptr = &i2c_smbus_read_byte_data;
+ config = config_read_fn_ptr(client, ADM1275_PMON_CONFIG);
+ if (config < 0)
+ return config;
+
+ device_config = config_read_fn_ptr(client, ADM1275_DEVICE_CONFIG);
+ if (device_config < 0)
+ return device_config;
+
info = &data->info;
info->pages = 1;
--
2.27.0.383.g050319c2ae-goog
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] hwmon: adm1275: Make sure we are reading enough data for different chips
2020-07-08 23:53 [PATCH] hwmon: adm1275: Make sure we are reading enough data for different chips Chu Lin
@ 2020-07-09 0:33 ` Guenter Roeck
2020-07-09 3:30 ` Chu Lin
0 siblings, 1 reply; 4+ messages in thread
From: Guenter Roeck @ 2020-07-09 0:33 UTC (permalink / raw)
To: Chu Lin
Cc: belgaied, jasonling, jdelvare, linux-hwmon, linux-kernel, zhongqil
On 7/8/20 4:53 PM, Chu Lin wrote:
> Issue:
> When binding adm1272 to the adm1275 driver, PEC error is reported.
> See blow:
s/blow/below/
Also, unless I am missing something, the error is only seen if PEC is
enabled.
> adm1275: probe of xxxx failed with error -74
>
> Diagnosis:
> Per the datasheet of adm1272 and adm1278 (www.analog.com),
> PMON_CONFIG (0xd4) is 16bits wide. On the other hand,
> PMON_CONFIG (0xd4) for adm1275 is 8bits wide.
> The driver should not assume everything is 8bits wide and read only
> 8bits from it.
>
> Solution:
> if it is adm1272 or adm1278, use i2c_read_word. Else, use i2c_read_byte
>
See below for more chips with 16-bit configuration registers.
> Signed-off-by: Chu Lin <linchuyuan@google.com>
> ---
> drivers/hwmon/pmbus/adm1275.c | 24 ++++++++++++++++--------
> 1 file changed, 16 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/hwmon/pmbus/adm1275.c b/drivers/hwmon/pmbus/adm1275.c
> index e25f541227da..a0d547d20358 100644
> --- a/drivers/hwmon/pmbus/adm1275.c
> +++ b/drivers/hwmon/pmbus/adm1275.c
> @@ -472,6 +472,7 @@ static int adm1275_probe(struct i2c_client *client,
> struct adm1275_data *data;
> const struct i2c_device_id *mid;
> const struct coefficients *coefficients;
> + s32 (*config_read_fn_ptr)(const struct i2c_client *client, u8 reg);
_ptr is really not needed here and redundant. A variable pointing to a function
is always a pointer.
> int vindex = -1, voindex = -1, cindex = -1, pindex = -1;
> int tindex = -1;
> u32 shunt;
> @@ -510,14 +511,6 @@ static int adm1275_probe(struct i2c_client *client,
> "Device mismatch: Configured %s, detected %s\n",
> id->name, mid->name);
>
> - config = i2c_smbus_read_byte_data(client, ADM1275_PMON_CONFIG);
> - if (config < 0)
> - return config;
> -
> - device_config = i2c_smbus_read_byte_data(client, ADM1275_DEVICE_CONFIG);
> - if (device_config < 0)
> - return device_config;
> -
The reason for doing this here was to avoid the memory allocation failure
on error. I don't really see the point of moving the code block.
> data = devm_kzalloc(&client->dev, sizeof(struct adm1275_data),
> GFP_KERNEL);
> if (!data)
> @@ -532,6 +525,21 @@ static int adm1275_probe(struct i2c_client *client,
>
> data->id = mid->driver_data;
>
> + /* adm1272 and adm1278 supports temperature monitoring. The config and device config
> + * are 16bits wide for these two devices. On the other hand, other devices are 8 bits wide
> + */
Standard multi-line comments, please. Also, the destinction is really
based on have_power_sampling, though that is set only later.
> + if (data->id == adm1272 || data->id == adm1278)
> + config_read_fn_ptr = &i2c_smbus_read_word_data;
Function pointers don't need &.
For ADM1293 and ADM1294, the registers are also 16 bit wide
(again, see use of have_power_sampling).
Thanks,
Guenter
> + else
> + config_read_fn_ptr = &i2c_smbus_read_byte_data;
> + config = config_read_fn_ptr(client, ADM1275_PMON_CONFIG);
> + if (config < 0)
> + return config;
> +
> + device_config = config_read_fn_ptr(client, ADM1275_DEVICE_CONFIG);
> + if (device_config < 0)
> + return device_config;
> +
> info = &data->info;
>
> info->pages = 1;
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] hwmon: adm1275: Make sure we are reading enough data for different chips
2020-07-09 0:33 ` Guenter Roeck
@ 2020-07-09 3:30 ` Chu Lin
2020-07-09 3:57 ` Guenter Roeck
0 siblings, 1 reply; 4+ messages in thread
From: Chu Lin @ 2020-07-09 3:30 UTC (permalink / raw)
To: Guenter Roeck
Cc: Kais Belgaied, Jason Ling, jdelvare, linux-hwmon, linux-kernel,
Zhongqi Li
On Wed, Jul 8, 2020 at 5:33 PM Guenter Roeck <linux@roeck-us.net> wrote:
>
> On 7/8/20 4:53 PM, Chu Lin wrote:
> > Issue:
> > When binding adm1272 to the adm1275 driver, PEC error is reported.
> > See blow:
>
> s/blow/below/
>
> Also, unless I am missing something, the error is only seen if PEC is
> enabled.
This is correct.
Regards,
Chu
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] hwmon: adm1275: Make sure we are reading enough data for different chips
2020-07-09 3:30 ` Chu Lin
@ 2020-07-09 3:57 ` Guenter Roeck
0 siblings, 0 replies; 4+ messages in thread
From: Guenter Roeck @ 2020-07-09 3:57 UTC (permalink / raw)
To: Chu Lin
Cc: Kais Belgaied, Jason Ling, jdelvare, linux-hwmon, linux-kernel,
Zhongqi Li
On 7/8/20 8:30 PM, Chu Lin wrote:
> On Wed, Jul 8, 2020 at 5:33 PM Guenter Roeck <linux@roeck-us.net> wrote:
>>
>> On 7/8/20 4:53 PM, Chu Lin wrote:
>>> Issue:
>>> When binding adm1272 to the adm1275 driver, PEC error is reported.
>>> See blow:
>>
>> s/blow/below/
>>
>> Also, unless I am missing something, the error is only seen if PEC is
>> enabled.
>
> This is correct.
>
That should be mentioned in the description.
Thanks,
Guenter
> Regards,
> Chu
>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2020-07-08 23:53 [PATCH] hwmon: adm1275: Make sure we are reading enough data for different chips Chu Lin
2020-07-09 0:33 ` Guenter Roeck
2020-07-09 3:30 ` Chu Lin
2020-07-09 3:57 ` Guenter Roeck
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