[PATCH linux dev-4.10 v4 2/2] hwmon: (ucd9000) Add debugfs for mfr_status info

Christopher Bostic cbostic at linux.vnet.ibm.com
Fri Aug 25 04:53:30 AEST 2017



On 8/21/17 9:01 PM, Andrew Jeffery wrote:
> On Mon, 2017-08-21 at 17:09 -0500, Christopher Bostic wrote:
>> Add debugfs to list the mfr_status register and its gpiN_fault
>> fields.
>>   
>>> Signed-off-by: Christopher Bostic <cbostic at linux.vnet.ibm.com>
>> ---
>> v2 - Remove mfr_status directory in debugfs and place the files
>>       up in the parent ucd9000 directory.
>> ---
>>   drivers/hwmon/pmbus/ucd9000.c | 122 ++++++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 122 insertions(+)
>>   
>> diff --git a/drivers/hwmon/pmbus/ucd9000.c b/drivers/hwmon/pmbus/ucd9000.c
>> index 5cea5f6..f906d8e 100644
>> --- a/drivers/hwmon/pmbus/ucd9000.c
>> +++ b/drivers/hwmon/pmbus/ucd9000.c
>> @@ -19,6 +19,7 @@
>>    * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
>>    */
>>   
>> +#include <linux/debugfs.h>
>>   #include <linux/kernel.h>
>>   #include <linux/module.h>
>>   #include <linux/init.h>
>> @@ -38,6 +39,7 @@
>>>   #define UCD9000_FAN_CONFIG_INDEX	0xe7
>>>   #define UCD9000_FAN_CONFIG		0xe8
>>>   #define UCD9000_LOGGED_FAULTS		0xea
>>> +#define UCD9000_MFR_STATUS		0xf3
>>>   #define UCD9000_GPIO_SELECT		0xfa
>>>   #define UCD9000_GPIO_CONFIG		0xfb
>>>   #define UCD9000_DEVICE_ID		0xfd
>> @@ -56,16 +58,25 @@
>>>   #define UCD9000_MON_VOLTAGE_HW	4
>>   
>>>   #define UCD9000_NUM_FAN		4
>>> +#define UCD9000_NAME_SIZE	24
>>   
>>>   #define UCD90160_NUM_GPIOS	26
>>> +#define UCD90160_GPI_COUNT	8
>>> +#define UCD90160_GPI_FAULT_BASE	16
>>   
>>   struct ucd9000_data {
>>>   	u8 fan_data[UCD9000_NUM_FAN][I2C_SMBUS_BLOCK_MAX];
>>>   	struct pmbus_driver_info info;
>>>   	struct gpio_chip gpio;
>>>> +	struct dentry *debugfs;	/* debugfs device directory */
>>   };
>>   #define to_ucd9000_data(_info) container_of(_info, struct ucd9000_data, info)
>>   
>> +struct ucd9000_debugfs_entry {
>>> +	struct i2c_client *client;
>>> +	u8 index;
>> +};
>> +
>>   static int ucd9000_get_fan_config(struct i2c_client *client, int fan)
>>   {
>>>   	int fan_config = 0;
>> @@ -143,6 +154,7 @@ static int ucd9000_gpio_read_config(struct i2c_client *client,
>>>   	if (ret < 0) {
>>>   		dev_err(&client->dev, "Failed to select GPIO %d: %d\n", offset,
>>>   			ret);
>> +
> Can we fold the whitespace cleanups into the appropriate patch? Please audit
> the rest of the patch for similar issues.
Yes, will do that.


>>>   		return ret;
>>>   	}
>>   
>> @@ -157,6 +169,7 @@ static int ucd9000_gpio_get(struct gpio_chip *gc, unsigned int offset)
>>>   	ret = ucd9000_gpio_read_config(client, offset);
>>>   	if (ret < 0) {
>>>   		dev_err(&client->dev, "failed to read GPIO config\n");
>> +
>>>   		return ret;
>>>   	}
>>   
>> @@ -185,6 +198,108 @@ static int ucd9000_gpio_direction_input(struct gpio_chip *gc,
>>>   	return 0;
>>   }
>>   
>> +static struct dentry *ucd9000_debugfs_dir;
>> +
>> +#if IS_ENABLED(CONFIG_DEBUG_FS)
>> +static int ucd9000_get_mfr_status(struct i2c_client *client, u32 *buffer)
>> +{
>>> +	int ret;
>> +
>>> +	ret = pmbus_set_page(client, 0);
>>> +	if (ret < 0) {
>>> +		dev_err(&client->dev, "pmbus_set_page failed. rc:%d\n", ret);
>>> +		return ret;
>>> +	}
>>> +	return i2c_smbus_read_block_data(client, UCD9000_MFR_STATUS,
>>> +					(u8 *)buffer);
> I know you don't intend to support the device but this will cause stack
> corruption on the ucd90240. Maybe it's not worth fixing at the moment, but it's
> probably worth a comment. From the command reference, page 81:
>
> 	With the UCD90120 and UCD90124 devices, this command [MFR_STATUS] is 2
> 	bytes long (bits 0-15). With the UCD90240, this command is 5 bytes
> 	long. With all other devices, it is 4 bytes long.

Will add a comment.
>
>> +}
>> +
>> +static int ucd9000_debugfs_get_mfr_status_bit(void *data, u64 *val)
>> +{
>>> +	struct ucd9000_debugfs_entry *entry = data;
>>> +	struct i2c_client *client = entry->client;
>>> +	int nr = entry->index;
>>> +	u32 buffer;
>>> +	int ret;
>> +
>>> +	ret = ucd9000_get_mfr_status(client, &buffer);
>>> +	if (ret < 0) {
>>> +		dev_err(&client->dev,
>>> +			"Failed to read mfr status. rc:%d\n", ret);
>>> +		return ret;
>>> +	}
>> +
>>> +	*val = ret & BIT(nr) ? 1 : 0;
> We should switch this to the non-branchy solution.

Will fix.
>
>> +
>>> +	return 0;
>> +}
>> +DEFINE_DEBUGFS_ATTRIBUTE(ucd9000_debugfs_ops_mfr_status_bit,
>>> +			ucd9000_debugfs_get_mfr_status_bit, NULL, "%1lld\n");
>> +
>> +static int ucd9000_debugfs_get_mfr_status_word(void *data, u64 *val)
>> +{
>>> +	struct ucd9000_debugfs_entry *entry = data;
>>> +	struct i2c_client *client = entry->client;
>>> +	u32 buffer;
>>> +	int ret;
>> +
>>> +	ret = ucd9000_get_mfr_status(client, &buffer);
>>> +	if (ret < 0) {
>>> +		dev_err(&client->dev,
>>> +			"Failed to read mfr status. rc:%d\n", ret);
>>> +		return ret;
>>> +	}
>> +
>>> +	*val = ret;
>> +
>>> +	return 0;
>> +}
>> +DEFINE_DEBUGFS_ATTRIBUTE(ucd9000_debugfs_ops_mfr_status_word,
>>> +			ucd9000_debugfs_get_mfr_status_word, NULL, "%08llx\n");
>> +
>> +static int ucd9000_init_debugfs(struct i2c_client *client,
>>> +				struct ucd9000_data *data)
>> +{
>>> +	struct ucd9000_debugfs_entry *entries;
>>> +	char name[UCD9000_NAME_SIZE];
>>> +	int i;
>> +
>>> +	ucd9000_debugfs_dir = debugfs_create_dir("ucd9000", NULL);
>>> +	if (IS_ERR(ucd9000_debugfs_dir)) {
>>> +		ucd9000_debugfs_dir = NULL;
>>> +		dev_warn(&client->dev, "Failed to create debugfs dir\n");
>>> +		return 0;
>>> +	}
>> +
>>> +	entries = devm_kzalloc(&client->dev, sizeof(*entries) *
>>> +				(UCD90160_GPI_COUNT + 1) * 10,
>>> +				GFP_KERNEL);
>>> +	if (!entries)
>>> +		return -ENOMEM;
>> +
>>> +	for (i = 0; i < UCD90160_GPI_COUNT; i++) {
>>> +		entries[i].client = client;
>>> +		entries[i].index = UCD90160_GPI_FAULT_BASE + i;
>>> +		scnprintf(name, UCD9000_NAME_SIZE, "gpi%d_alarm", i+1);
>>> +		debugfs_create_file(name, 0444, ucd9000_debugfs_dir,
>>> +				&entries[i],
>>> +				&ucd9000_debugfs_ops_mfr_status_bit);
>>> +	}
>>> +	entries[i].client = client;
>>> +	scnprintf(name, UCD9000_NAME_SIZE, "mfr_status");
>>> +	debugfs_create_file(name, 0444, ucd9000_debugfs_dir, &entries[i],
>>> +				&ucd9000_debugfs_ops_mfr_status_word);
> Given the static ucd9000_debugfs_dir, how does this work if there are multiple
> devices? It's a naive question - I haven't looked into it at all, but I'm
> curious.
Right, this won't work well given that.   Will add some unique 
identifier for each device.

Thanks,
Chris

> Cheers,
>
> Andrew
>
>> +
>>> +	return 0;
>> +}
>> +#else
>> +static int ucd9000_init_debugfs(struct i2c_client *client,
>>> +				struct ucd9000_data *data)
>> +{
>>> +	return 0;
>> +}
>> +#endif /* IS_ENABLED(CONFIG_DEBUG_FS) */
>> +
>>   static ssize_t ucd9000_clear_logged_faults(struct device *dev,
>>>   				struct device_attribute *attr, const char *buf,
>>>   				size_t count)
>> @@ -345,12 +460,19 @@ static int ucd9000_probe(struct i2c_client *client,
>>>   	if (ret < 0)
>>>   		return ret;
>>   
>>> +	if (mid->driver_data == ucd90160) {
>>> +		ret = ucd9000_init_debugfs(client, data);
>>> +		if (ret < 0)
>>> +			dev_warn(&client->dev, "Failed to register debugfs\n");
>>> +	}
>> +
>>>   	return  pmbus_do_probe(client, mid, info);
>>   }
>>   
>>   static int ucd9000_remove(struct i2c_client *client)
>>   {
>>>   	sysfs_remove_group(&client->dev.kobj, &ucd9000_attr_group);
>>> +	debugfs_remove_recursive(ucd9000_debugfs_dir);
>>>   	return pmbus_do_remove(client);
>>   }
>>   



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