Messages in this thread | | | Subject | Re: [PATCH v2 4/4] hwmon: (pmbus): Add debugfs for status registers | From | Guenter Roeck <> | Date | Fri, 11 Aug 2017 06:52:45 -0700 |
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On 08/10/2017 02:57 PM, Eddie James wrote: > From: "Edward A. James" <eajames@us.ibm.com> > > Export all the available status registers through debugfs, if the client > driver wants them. > > Signed-off-by: Edward A. James <eajames@us.ibm.com> > --- > drivers/hwmon/pmbus/pmbus.h | 6 ++ > drivers/hwmon/pmbus/pmbus_core.c | 201 +++++++++++++++++++++++++++++++++++++++ > 2 files changed, 207 insertions(+) > > diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h > index bfcb13b..5f91a19 100644 > --- a/drivers/hwmon/pmbus/pmbus.h > +++ b/drivers/hwmon/pmbus/pmbus.h > @@ -383,6 +383,12 @@ struct pmbus_driver_info { > /* Regulator functionality, if supported by this chip driver. */ > int num_regulators; > const struct regulator_desc *reg_desc; > + > + /* > + * Controls whether or not to create debugfs entries for this driver's > + * devices. > + */ > + bool debugfs; > }; > > /* Regulator ops */ > diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c > index ef135d8..b11ebec 100644 > --- a/drivers/hwmon/pmbus/pmbus_core.c > +++ b/drivers/hwmon/pmbus/pmbus_core.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> > @@ -101,6 +102,7 @@ struct pmbus_data { > int num_attributes; > struct attribute_group group; > const struct attribute_group *groups[2]; > + struct dentry *debugfs; /* debugfs device directory */ > > struct pmbus_sensor *sensors; > > @@ -120,6 +122,12 @@ struct pmbus_data { > u8 currpage; > }; > > +struct pmbus_debugfs_entry { > + struct i2c_client *client; > + u8 page; > + u8 reg; > +}; > + > void pmbus_clear_cache(struct i2c_client *client) > { > struct pmbus_data *data = i2c_get_clientdata(client); > @@ -1893,6 +1901,184 @@ static int pmbus_regulator_register(struct pmbus_data *data) > } > #endif > > +static struct dentry *pmbus_debugfs_dir; /* pmbus debugfs directory */ > + > +#if IS_ENABLED(CONFIG_DEBUG_FS) > +static int pmbus_debugfs_get(void *data, u64 *val) > +{ > + struct pmbus_debugfs_entry *entry = data; > + > + *val = _pmbus_read_byte_data(entry->client, entry->page, entry->reg); > + > + return 0; > +} > +DEFINE_DEBUGFS_ATTRIBUTE(pmbus_debugfs_ops, pmbus_debugfs_get, NULL, > + "0x%02llx\n"); > + > +static int pmbus_debugfs_get_status(void *data, u64 *val) > +{ > + struct pmbus_debugfs_entry *entry = data; > + struct pmbus_data *pdata = i2c_get_clientdata(entry->client); > + > + *val = pdata->read_status(entry->client, entry->page); > + > + return 0; > +} > +DEFINE_DEBUGFS_ATTRIBUTE(pmbus_debugfs_ops_status, pmbus_debugfs_get_status, > + NULL, "0x%04llx\n"); > + > +static int pmbus_init_debugfs(struct i2c_client *client, > + struct pmbus_data *data) > +{ > + int i, idx = 0; > + char name[PMBUS_NAME_SIZE]; > + struct pmbus_debugfs_entry *entries; > + > + /* Check if client driver requested debugfs support. */ > + if (!data->info->debugfs) > + return 0; > +
Let's just make this unconditional and drop the flag. I don't see the value in enabling it per driver. The code is there anyway, might as well support it.
> + /* Create the root pmbus debugfs directory if it's not created yet. */ > + if (!pmbus_debugfs_dir) { > + pmbus_debugfs_dir = debugfs_create_dir("pmbus", NULL); > + if (IS_ERR_OR_NULL(pmbus_debugfs_dir)) { > + pmbus_debugfs_dir = NULL; > + return -ENODEV; > + } > + } > + > + /* > + * Create the debugfs directory for this device. Use the hwmon device > + * name to avoid conflicts (hwmon numbers are globally unique). > + */ > + data->debugfs = debugfs_create_dir(dev_name(data->hwmon_dev), > + pmbus_debugfs_dir); > + if (IS_ERR_OR_NULL(data->debugfs)) { > + data->debugfs = NULL; > + return -ENODEV; > + } > + > + /* Allocate the max possible entries we need. */ > + entries = devm_kzalloc(data->dev, > + sizeof(*entries) * (data->info->pages * 10), > + GFP_KERNEL); > + if (!entries) > + return -ENOMEM; > + > + for (i = 0; i < data->info->pages; ++i) { > + /* Check accessibility of status register if it's not page 0 */ > + if (!i || pmbus_check_status_register(client, i)) { > + /* No need to set reg as we have special read op. */ > + entries[idx].client = client; > + entries[idx].page = i; > + snprintf(name, PMBUS_NAME_SIZE, "status%d", i);
scnprintf might be better.
> + debugfs_create_file(name, 0444, data->debugfs, > + &entries[idx++], > + &pmbus_debugfs_ops_status); > + } > + > + if (data->info->func[i] & PMBUS_HAVE_STATUS_VOUT) { > + entries[idx].client = client; > + entries[idx].page = i; > + entries[idx].reg = PMBUS_STATUS_VOUT; > + snprintf(name, PMBUS_NAME_SIZE, "status%d_vout", i); > + debugfs_create_file(name, 0444, data->debugfs, > + &entries[idx++], > + &pmbus_debugfs_ops); > + } > + > + if (data->info->func[i] & PMBUS_HAVE_STATUS_IOUT) { > + entries[idx].client = client; > + entries[idx].page = i; > + entries[idx].reg = PMBUS_STATUS_IOUT; > + snprintf(name, PMBUS_NAME_SIZE, "status%d_iout", i); > + debugfs_create_file(name, 0444, data->debugfs, > + &entries[idx++], > + &pmbus_debugfs_ops); > + } > + > + if (data->info->func[i] & PMBUS_HAVE_STATUS_INPUT) { > + entries[idx].client = client; > + entries[idx].page = i; > + entries[idx].reg = PMBUS_STATUS_INPUT; > + snprintf(name, PMBUS_NAME_SIZE, "status%d_input", i); > + debugfs_create_file(name, 0444, data->debugfs, > + &entries[idx++], > + &pmbus_debugfs_ops); > + } > + > + if (data->info->func[i] & PMBUS_HAVE_STATUS_TEMP) { > + entries[idx].client = client; > + entries[idx].page = i; > + entries[idx].reg = PMBUS_STATUS_TEMPERATURE; > + snprintf(name, PMBUS_NAME_SIZE, "status%d_temp", i); > + debugfs_create_file(name, 0444, data->debugfs, > + &entries[idx++], > + &pmbus_debugfs_ops); > + } > + > + if (pmbus_check_byte_register(client, i, PMBUS_STATUS_CML)) { > + entries[idx].client = client; > + entries[idx].page = i; > + entries[idx].reg = PMBUS_STATUS_CML; > + snprintf(name, PMBUS_NAME_SIZE, "status%d_cml", i); > + debugfs_create_file(name, 0444, data->debugfs, > + &entries[idx++], > + &pmbus_debugfs_ops); > + } > + > + if (pmbus_check_byte_register(client, i, PMBUS_STATUS_OTHER)) { > + entries[idx].client = client; > + entries[idx].page = i; > + entries[idx].reg = PMBUS_STATUS_OTHER; > + snprintf(name, PMBUS_NAME_SIZE, "status%d_other", i); > + debugfs_create_file(name, 0444, data->debugfs, > + &entries[idx++], > + &pmbus_debugfs_ops); > + } > + > + if (pmbus_check_byte_register(client, i, > + PMBUS_STATUS_MFR_SPECIFIC)) { > + entries[idx].client = client; > + entries[idx].page = i; > + entries[idx].reg = PMBUS_STATUS_MFR_SPECIFIC; > + snprintf(name, PMBUS_NAME_SIZE, "status%d_mfr", i); > + debugfs_create_file(name, 0444, data->debugfs, > + &entries[idx++], > + &pmbus_debugfs_ops); > + } > + > + if (data->info->func[i] & PMBUS_HAVE_STATUS_FAN12) { > + entries[idx].client = client; > + entries[idx].page = i; > + entries[idx].reg = PMBUS_STATUS_FAN_12; > + snprintf(name, PMBUS_NAME_SIZE, "status%d_fan12", i); > + debugfs_create_file(name, 0444, data->debugfs, > + &entries[idx++], > + &pmbus_debugfs_ops); > + } > + > + if (data->info->func[i] & PMBUS_HAVE_STATUS_FAN34) { > + entries[idx].client = client; > + entries[idx].page = i; > + entries[idx].reg = PMBUS_STATUS_FAN_34; > + snprintf(name, PMBUS_NAME_SIZE, "status%d_fan34", i); > + debugfs_create_file(name, 0444, data->debugfs, > + &entries[idx++], > + &pmbus_debugfs_ops); > + } > + } > + > + return 0; > +} > +#else > +static int pmbus_init_debugfs(struct i2c_client *client, > + struct pmbus_data *data) > +{ > + return 0; > +} > +#endif /* IS_ENABLED(CONFIG_DEBUG_FS) */ > + > int pmbus_do_probe(struct i2c_client *client, const struct i2c_device_id *id, > struct pmbus_driver_info *info) > { > @@ -1952,6 +2138,10 @@ int pmbus_do_probe(struct i2c_client *client, const struct i2c_device_id *id, > if (ret) > goto out_unregister; > > + ret = pmbus_init_debugfs(client, data); > + if (ret) > + dev_warn(dev, "Failed to register debugfs\n"); > + > return 0; > > out_unregister: > @@ -1965,6 +2155,17 @@ int pmbus_do_probe(struct i2c_client *client, const struct i2c_device_id *id, > int pmbus_do_remove(struct i2c_client *client) > { > struct pmbus_data *data = i2c_get_clientdata(client); > + > + debugfs_remove_recursive(data->debugfs); > + if (pmbus_debugfs_dir && simple_empty(pmbus_debugfs_dir)) {
Almost. Problem is that it is racy against insertions. We would need a mutex to protect write accesses to pmbus_debugfs_dir. Wonder if we can just add module_init/module_exit to pmbus_core.c and initialize/remove the directory from there.
Guenter
> + /* > + * Remove the root pmbus debugfs directory if we've removed > + * all the device directories underneath already. > + */ > + debugfs_remove(pmbus_debugfs_dir); > + pmbus_debugfs_dir = NULL; > + } > + > hwmon_device_unregister(data->hwmon_dev); > kfree(data->group.attrs); > return 0; >
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