Messages in this thread | | | Subject | Re: [PATCH 2/2] hwmon: (ucd9000) Add debugfs attributes to provide mfr_status | From | Guenter Roeck <> | Date | Sat, 10 Mar 2018 08:50:55 -0800 |
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On 03/09/2018 11:19 AM, Eddie James wrote: > From: Christopher Bostic <cbostic@linux.vnet.ibm.com> > > Expose the gpiN_fault fields of mfr_status as individual debugfs > attributes. This provides a way for users to be easily notified of gpi > faults. Also provide the whole mfr_status register in debugfs. > > Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com> > Signed-off-by: Andrew Jeffery <andrew@aj.id.au> > Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com> > --- > drivers/hwmon/pmbus/ucd9000.c | 172 +++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 171 insertions(+), 1 deletion(-) > > diff --git a/drivers/hwmon/pmbus/ucd9000.c b/drivers/hwmon/pmbus/ucd9000.c > index e3a507f..297da0e 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/of_device.h> > @@ -36,6 +37,7 @@ > #define UCD9000_NUM_PAGES 0xd6 > #define UCD9000_FAN_CONFIG_INDEX 0xe7 > #define UCD9000_FAN_CONFIG 0xe8 > +#define UCD9000_MFR_STATUS 0xf3 > #define UCD9000_GPIO_SELECT 0xfa > #define UCD9000_GPIO_CONFIG 0xfb > #define UCD9000_DEVICE_ID 0xfd > @@ -63,13 +65,22 @@ > #define UCD901XX_NUM_GPIOS 26 > #define UCD90910_NUM_GPIOS 26 > > +#define UCD9000_DEBUGFS_NAME_LEN 24 > +#define UCD9000_GPI_COUNT 8 > + > 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; > @@ -328,6 +339,156 @@ static int ucd9000_gpio_direction_output(struct gpio_chip *gc, > val); > } > > +#if IS_ENABLED(CONFIG_DEBUG_FS) > +static int ucd9000_get_mfr_status(struct i2c_client *client, u8 *buffer) > +{ > + int ret = pmbus_set_page(client, 0); > + > + if (ret < 0) > + return ret; > + > + /* > + * 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. > + */ > + return i2c_smbus_read_block_data(client, UCD9000_MFR_STATUS, buffer); > +} > + > +static int ucd9000_debugfs_show_mfr_status_bit(void *data, u64 *val) > +{ > + struct ucd9000_debugfs_entry *entry = data; > + struct i2c_client *client = entry->client; > + u8 buffer[4]; > + int ret; > + > + /* > + * This attribute is only created for devices that return 4 bytes for > + * status_mfr, so it's safe to call with 4-byte buffer. > + */ > + 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; > + } > + > + /* > + * Attribute only created for devices with gpi fault bits at bits > + * 16-23, which is the second byte of the response. > + */ > + *val = !!(buffer[1] & BIT(entry->index)); > + > + return 0; > +} > +DEFINE_DEBUGFS_ATTRIBUTE(ucd9000_debugfs_mfr_status_bit, > + ucd9000_debugfs_show_mfr_status_bit, NULL, "%1lld\n"); > + > +static int ucd9000_debugfs_show_mfr_status_word2(void *data, u64 *val) > +{ > + struct i2c_client *client = data; > + __be16 buffer; > + int ret; > + > + ret = ucd9000_get_mfr_status(client, (u8 *)&buffer); > + if (ret < 0) { > + dev_err(&client->dev, "Failed to read mfr status. rc:%d\n", > + ret); > + > + return ret; > + } > + > + *val = be16_to_cpu(buffer); > + > + return 0; > +} > +DEFINE_DEBUGFS_ATTRIBUTE(ucd9000_debugfs_mfr_status_word2, > + ucd9000_debugfs_show_mfr_status_word2, NULL, > + "%04llx\n"); > + > +static int ucd9000_debugfs_show_mfr_status_word4(void *data, u64 *val) > +{ > + struct i2c_client *client = data; > + __be32 buffer; > + int ret; > + > + ret = ucd9000_get_mfr_status(client, (u8 *)&buffer); > + if (ret < 0) { > + dev_err(&client->dev, "Failed to read mfr status. rc:%d\n", > + ret); > + > + return ret; > + } > + > + *val = be32_to_cpu(buffer); > + > + return 0; > +} > +DEFINE_DEBUGFS_ATTRIBUTE(ucd9000_debugfs_mfr_status_word4, > + ucd9000_debugfs_show_mfr_status_word4, NULL, > + "%08llx\n"); > + > +static int ucd9000_init_debugfs(struct i2c_client *client, > + const struct i2c_device_id *mid, > + struct ucd9000_data *data) > +{ > + struct dentry *debugfs; > + struct ucd9000_debugfs_entry *entries; > + int i; > + char name[UCD9000_DEBUGFS_NAME_LEN]; > + > + debugfs = pmbus_get_debugfs_dir(client); > + if (!debugfs) > + return -ENOENT; > + > + data->debugfs = debugfs_create_dir(client->name, debugfs); > + if (!data->debugfs) > + return -ENOENT; > + > + /* > + * Of the chips this driver supports, only the UCD9090, UCD90160, > + * and UCD90910 report GPI faults in their MFR_STATUS register, so only > + * create the GPI fault debugfs attributes for those chips. > + */ > + if (mid->driver_data == ucd9090 || mid->driver_data == ucd90160 || > + mid->driver_data == ucd90910) { > + entries = devm_kzalloc(&client->dev, > + sizeof(*entries) * UCD9000_GPI_COUNT, > + GFP_KERNEL); > + if (!entries) > + return -ENOMEM; > + > + for (i = 0; i < UCD9000_GPI_COUNT; i++) { > + entries[i].client = client; > + entries[i].index = i; > + scnprintf(name, UCD9000_DEBUGFS_NAME_LEN, > + "gpi%d_alarm", i + 1); > + debugfs_create_file(name, 0444, data->debugfs, > + &entries[i], > + &ucd9000_debugfs_mfr_status_bit); > + } > + > + scnprintf(name, UCD9000_DEBUGFS_NAME_LEN, "mfr_status"); > + debugfs_create_file(name, 0444, data->debugfs, client, > + &ucd9000_debugfs_mfr_status_word4); > + } else if (mid->driver_data == ucd90120 || > + mid->driver_data == ucd90124) { > + scnprintf(name, UCD9000_DEBUGFS_NAME_LEN, "mfr_status"); > + debugfs_create_file(name, 0444, data->debugfs, client, > + &ucd9000_debugfs_mfr_status_word2); > + } > + > + return 0; > +}
Is all that complexity really worth it ? Why not just read the manufacturing status as byte string into a buffer and use hexdump to pront it, no matter how many bytes are actually returned ? This would also be less error prone, and automatically support future chips.
Thanks, Guenter
> +#else > +static int ucd9000_init_debugfs(struct i2c_client *client, > + struct ucd9000_data *data) > +{ > + return 0; > +} > +#endif /* IS_ENABLED(CONFIG_DEBUG_FS) */ > + > static int ucd9000_probe(struct i2c_client *client, > const struct i2c_device_id *id) > { > @@ -483,7 +644,16 @@ static int ucd9000_probe(struct i2c_client *client, > return ret; > } > > - return pmbus_do_probe(client, mid, info); > + ret = pmbus_do_probe(client, mid, info); > + if (ret) > + return ret; > + > + ret = ucd9000_init_debugfs(client, mid, data); > + if (ret) > + dev_warn(&client->dev, "Failed to register debugfs: %d\n", > + ret); > + > + return 0; > } > > /* This is the driver that will be inserted */ >
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