Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752800AbdHNO6V (ORCPT ); Mon, 14 Aug 2017 10:58:21 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:45234 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752547AbdHNO6S (ORCPT ); Mon, 14 Aug 2017 10:58:18 -0400 Subject: Re: [PATCH v2 4/4] hwmon: (pmbus): Add debugfs for status registers To: Guenter Roeck Cc: jdelvare@suse.com, linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org, joel@jms.id.au, jk@ozlabs.org, andrew@aj.id.au, cbostic@linux.vnet.ibm.com, "Edward A. James" References: <1502402270-15328-1-git-send-email-eajames@linux.vnet.ibm.com> <1502402270-15328-5-git-send-email-eajames@linux.vnet.ibm.com> <53a4c08d-348b-5dcb-b504-c37caf7d227c@roeck-us.net> From: Eddie James Date: Mon, 14 Aug 2017 09:58:07 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.0 MIME-Version: 1.0 In-Reply-To: <53a4c08d-348b-5dcb-b504-c37caf7d227c@roeck-us.net> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-TM-AS-GCONF: 00 x-cbid: 17081414-0012-0000-0000-000014D52C04 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00007543; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000220; SDB=6.00902223; UDB=6.00451853; IPR=6.00682439; BA=6.00005531; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00016689; XFM=3.00000015; UTC=2017-08-14 14:58:16 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17081414-0013-0000-0000-00004F0CA7BE Message-Id: <8f797d36-8e19-ebe7-ad75-72e5c0ea759a@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-08-14_13:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1706020000 definitions=main-1708140243 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 11137 Lines: 308 On 08/11/2017 08:52 AM, Guenter Roeck wrote: > On 08/10/2017 02:57 PM, Eddie James wrote: >> From: "Edward A. James" >> >> Export all the available status registers through debugfs, if the client >> driver wants them. >> >> Signed-off-by: Edward A. James >> --- >> 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 >> #include >> #include >> #include >> @@ -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. Got it, this worked well. Will send up v3 for this patch. Thanks for merging the others! Eddie > > 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; >> >