[PATCH linux dev-4.10 v5 2/2] hwmon: (ucd9000) Add debugfs for mfr_status info

Andrew Jeffery andrew at aj.id.au
Wed Aug 30 13:59:23 AEST 2017


On Tue, 2017-08-29 at 15:08 -0500, Christopher Bostic wrote:
> Add debugfs to list mfr_status register and its gpiN_fault fields.
> 
> > Signed-off-by: Christopher Bostic <cbostic at linux.vnet.ibm.com>
> ---
> v5 - Add unique debugfs dir ID for each ucd9000 sysfs device.
>    - Change branching return to a !! method.
>    - Clean up line breaks, other white space.
>    - Add comments on assumptions made regarding ucd90160 versus other
>      types.
> v2 - Remove mfr_status directory in debugfs and place the files
>      up in the parent ucd9000 directory.
> ---
>  drivers/hwmon/pmbus/ucd9000.c | 154 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 154 insertions(+)
> 
> diff --git a/drivers/hwmon/pmbus/ucd9000.c b/drivers/hwmon/pmbus/ucd9000.c
> index cfd7703..edb026f 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>
> @@ -29,6 +30,7 @@
>  #include <linux/sysfs.h>
>  #include <linux/hwmon-sysfs.h>
>  #include <linux/gpio.h>
> +#include <linux/idr.h>
>  #include "pmbus.h"
>  
>  enum chips { ucd9000, ucd90120, ucd90124, ucd90160, ucd9090, ucd90910 };
> @@ -38,6 +40,7 @@
> >  #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
> @@ -59,17 +62,28 @@
> >  #define UCD9000_MON_VOLTAGE_HW	4
>  
> >  #define UCD9000_NUM_FAN		4
> > +#define UCD9000_NAME_SIZE	24
>  
> >  #define UCD9000_GPIO_NAME_LEN	16
> >  #define UCD90160_NUM_GPIOS	26
> > +#define UCD90160_GPI_COUNT	8
> > +#define UCD90160_GPI_FAULT_BASE	16
> +
> +static DEFINE_IDA(ucd9000_ida);
>  
>  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;
>  };
>  #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;
> @@ -297,6 +311,138 @@ static int ucd9000_gpio_direction_output(struct gpio_chip *gc,
> >  	return ucd9000_gpio_set_direction(gc, offset, UCD9000_GPIO_OUTPUT, val);
>  }
>  
> +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;
> > +	}
> +
> > +	/*
> > +	 * Warning:
> > +	 *
> > +	 * Though not currently supported this will cause stack corruption for
> > +	 * ucd90240!  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.
> +	 */

Hopefully it won't be missed :)

> +	return i2c_smbus_read_block_data(client, UCD9000_MFR_STATUS,
> > +					(u8 *)buffer);
> +}
> +
> +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));
> +
> > +	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;
> +
> > +	i = ida_simple_get(&ucd9000_ida, 0, INT_MAX, GFP_KERNEL);
> > +	scnprintf(name, UCD9000_NAME_SIZE, "ucd9000.%d", i);

Given it's debugfs it doesn't matter for the moment, but I do wonder whether we
should use the actual device name rather than the driver name here. Some thing
to fix later.

> > +	ucd9000_debugfs_dir = debugfs_create_dir(name, NULL);
> > +	if (IS_ERR(ucd9000_debugfs_dir)) {
> > +		dev_warn(&client->dev, "Failed to create debugfs dir: %p\n",
> > +			ucd9000_debugfs_dir);
> > +		ucd9000_debugfs_dir = NULL;
> +
> > +		return 0;
> > +	}
> +
> > +	/*
> > +	 * Warning:
> > +	 *
> > +	 * Makes assumption we're on a ucd90160 type! entries will be different
> > +	 * sizes for other types.
> > +	 */
> > +	entries = devm_kzalloc(&client->dev, sizeof(*entries) *
> > +				(UCD90160_GPI_COUNT + 1) * 10, GFP_KERNEL);
> > +	if (!entries)
> > +		return -ENOMEM;
> +
> > +	/*
> > +	 * Warning:
> > +	 *
> > +	 * This makes the assumption we're probing a ucd90160 type and how the
> > +	 * GPI information is organized.  Needs to account for all other
> > +	 * ucd9000 varieties.
> > +	 */
> > +	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);
> +
> > +	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)
> @@ -467,12 +613,20 @@ static int ucd9000_probe(struct i2c_client *client,
> >  		return ret;
> >  	}
>  
> > +	if (mid->driver_data == ucd90160) {
> > +		ret = ucd9000_init_debugfs(client, data);
> > +		if (ret < 0)
> > +			dev_warn(&client->dev,
> > +				"Failed to register debugfs: %d\n", ret);
> > +	}
> +
> >  	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);
>  }
>  

Looks good.

Thanks,

Andrew
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