From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752351AbeCMTCA (ORCPT ); Tue, 13 Mar 2018 15:02:00 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:54826 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751606AbeCMTB7 (ORCPT ); Tue, 13 Mar 2018 15:01:59 -0400 Subject: Re: [PATCH 2/2] hwmon: (ucd9000) Add debugfs attributes to provide mfr_status To: Guenter Roeck , linux-hwmon@vger.kernel.org Cc: linux-kernel@vger.kernel.org, jdelvare@suse.com, joel@jms.id.au, Christopher Bostic , Andrew Jeffery References: <1520623196-9534-1-git-send-email-eajames@linux.vnet.ibm.com> <1520623196-9534-3-git-send-email-eajames@linux.vnet.ibm.com> From: Eddie James Date: Tue, 13 Mar 2018 14:01:51 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-TM-AS-GCONF: 00 x-cbid: 18031319-0008-0000-0000-0000097411B1 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00008667; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000254; SDB=6.01002562; UDB=6.00510147; IPR=6.00781892; MB=3.00020012; MTD=3.00000008; XFM=3.00000015; UTC=2018-03-13 19:01:56 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18031319-0009-0000-0000-0000466126AC Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2018-03-13_08:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1803130212 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/10/2018 10:50 AM, Guenter Roeck wrote: > On 03/09/2018 11:19 AM, Eddie James wrote: >> From: Christopher Bostic >> >> 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 >> Signed-off-by: Andrew Jeffery >> Signed-off-by: Eddie James >> --- >>   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 >>   #include >>   #include >>   #include >> @@ -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. Hm, well then we have the additional complexity of setting up custom debugfs file operations to show the binary data instead of just using DEFINE_DEBUGFS_ATTRIBUTE. Plus, at some point someone has to interpret it as either a word, half-word, or 5 bytes chunk. Where better to do it than the driver, as this is hw-dependent? I could just use one function and do a byte-swap based on data length in a loop within #ifdef LITTLE_ENDIAN, but that's a little messy. It will handle all the cases though. What do you think? Thanks, Eddie > > 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 */ >> >