On Thu, Dec 07, 2017 at 01:50:38PM -0600, Eddie James wrote:
> From: "Edward A. James" <eaja...@us.ibm.com>
> 
> Add debugfs entries for additional power supply data, including part
> number, serial number, FRU number, firmware revision, ccin, and the
> input history of the power supply. The input history is 10 minutes of
> input power data in the form of twenty 30-second packets. Each packet
> contains average and maximum power for that 30 second period.
> 
> Signed-off-by: Edward A. James <eaja...@us.ibm.com>
> ---
>  drivers/hwmon/pmbus/ibm-cffps.c | 199 
> +++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 198 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/hwmon/pmbus/ibm-cffps.c b/drivers/hwmon/pmbus/ibm-cffps.c
> index cb56da6..6d19399 100644
> --- a/drivers/hwmon/pmbus/ibm-cffps.c
> +++ b/drivers/hwmon/pmbus/ibm-cffps.c
> @@ -8,12 +8,26 @@
>   */
>  
>  #include <linux/bitops.h>
> +#include <linux/debugfs.h>
>  #include <linux/device.h>
> +#include <linux/fs.h>
>  #include <linux/i2c.h>
> +#include <linux/jiffies.h>
>  #include <linux/module.h>
> +#include <linux/mutex.h>
>  
>  #include "pmbus.h"
>  
> +#define CFFPS_FRU_CMD                                0x9A
> +#define CFFPS_PN_CMD                         0x9B
> +#define CFFPS_SN_CMD                         0x9E
> +#define CFFPS_CCIN_CMD                               0xBD
> +#define CFFPS_FW_CMD_START                   0xFA
> +#define CFFPS_FW_NUM_BYTES                   4
> +
> +#define CFFPS_INPUT_HISTORY_CMD                      0xD6
> +#define CFFPS_INPUT_HISTORY_SIZE             100
> +
>  /* STATUS_MFR_SPECIFIC bits */
>  #define CFFPS_MFR_FAN_FAULT                  BIT(0)
>  #define CFFPS_MFR_THERMAL_FAULT                      BIT(1)
> @@ -24,6 +38,144 @@
>  #define CFFPS_MFR_VAUX_FAULT                 BIT(6)
>  #define CFFPS_MFR_CURRENT_SHARE_WARNING              BIT(7)
>  
> +enum {
> +     CFFPS_DEBUGFS_INPUT_HISTORY = 0,
> +     CFFPS_DEBUGFS_FRU,
> +     CFFPS_DEBUGFS_PN,
> +     CFFPS_DEBUGFS_SN,
> +     CFFPS_DEBUGFS_CCIN,
> +     CFFPS_DEBUGFS_FW,
> +     CFFPS_DEBUGFS_NUM_ENTRIES
> +};
> +
> +struct ibm_cffps_input_history {
> +     struct mutex update_lock;
> +     unsigned long last_update;
> +
> +     u8 byte_count;
> +     u8 data[CFFPS_INPUT_HISTORY_SIZE];
> +};
> +
> +struct ibm_cffps {
> +     struct i2c_client *client;
> +
> +     struct ibm_cffps_input_history input_history;
> +
> +     int debugfs_entries[CFFPS_DEBUGFS_NUM_ENTRIES];
> +};
> +
> +#define to_psu(x, y) container_of((x), struct ibm_cffps, 
> debugfs_entries[(y)])
> +
> +static ssize_t ibm_cffps_read_input_history(struct ibm_cffps *psu,
> +                                         char __user *buf, size_t count,
> +                                         loff_t *ppos)
> +{
> +     int rc;
> +     u8 msgbuf0[1] = { CFFPS_INPUT_HISTORY_CMD };
> +     u8 msgbuf1[CFFPS_INPUT_HISTORY_SIZE + 1] = { 0 };
> +     struct i2c_msg msg[2] = {
> +             {
> +                     .addr = psu->client->addr,
> +                     .flags = psu->client->flags,
> +                     .len = 1,
> +                     .buf = msgbuf0,
> +             }, {
> +                     .addr = psu->client->addr,
> +                     .flags = psu->client->flags | I2C_M_RD,
> +                     .len = CFFPS_INPUT_HISTORY_SIZE + 1,
> +                     .buf = msgbuf1,
> +             },
> +     };
> +
> +     if (!*ppos) {
> +             mutex_lock(&psu->input_history.update_lock);
> +             if (time_after(jiffies, psu->input_history.last_update + HZ)) {
> +                     /*
> +                      * Use a raw i2c transfer, since we need more bytes
> +                      * than Linux I2C supports through smbus xfr (only 32).
> +                      */
> +                     rc = i2c_transfer(psu->client->adapter, msg, 2);
> +                     if (rc < 0) {
> +                             mutex_unlock(&psu->input_history.update_lock);
> +                             return rc;
> +                     }
> +
> +                     psu->input_history.byte_count = msgbuf1[0];
> +                     memcpy(psu->input_history.data, &msgbuf1[1],
> +                            CFFPS_INPUT_HISTORY_SIZE);
> +                     psu->input_history.last_update = jiffies;
> +             }
> +
> +             mutex_unlock(&psu->input_history.update_lock);
> +     }
> +
> +     return simple_read_from_buffer(buf, count, ppos,
> +                                    psu->input_history.data,
> +                                    psu->input_history.byte_count);
> +}
> +
> +static ssize_t ibm_cffps_debugfs_op(struct file *file, char __user *buf,
> +                                 size_t count, loff_t *ppos)
> +{
> +     u8 cmd;
> +     int i, rc;
> +     int *idxp = file->private_data;
> +     int idx = *idxp;
> +     struct ibm_cffps *psu = to_psu(idxp, idx);
> +     char data[I2C_SMBUS_BLOCK_MAX] = { 0 };
> +
> +     switch (idx) {
> +     case CFFPS_DEBUGFS_INPUT_HISTORY:
> +             return ibm_cffps_read_input_history(psu, buf, count, ppos);
> +     case CFFPS_DEBUGFS_FRU:
> +             cmd = CFFPS_FRU_CMD;
> +             break;
> +     case CFFPS_DEBUGFS_PN:
> +             cmd = CFFPS_PN_CMD;
> +             break;
> +     case CFFPS_DEBUGFS_SN:
> +             cmd = CFFPS_SN_CMD;
> +             break;
> +     case CFFPS_DEBUGFS_CCIN:
> +             rc = i2c_smbus_read_word_data(psu->client, CFFPS_CCIN_CMD);
> +             if (rc < 0)
> +                     return rc;
> +
> +             rc = snprintf(data, 5, "%04X", rc);
> +             goto done;
> +     case CFFPS_DEBUGFS_FW:
> +             for (i = 0; i < CFFPS_FW_NUM_BYTES; ++i) {
> +                     rc = i2c_smbus_read_byte_data(psu->client,
> +                                                   CFFPS_FW_CMD_START + i);
> +                     if (rc < 0)
> +                             return rc;
> +
> +                     snprintf(&data[i * 2], 3, "%02X", rc);
> +             }
> +
> +             rc = i * 2;
> +             goto done;
> +     default:
> +             return -EINVAL;
> +     }
> +
> +     rc = i2c_smbus_read_block_data(psu->client, cmd, data);
> +     if (rc < 0)
> +             return rc;
> +
> +done:
> +     data[rc] = '\n';
> +     rc += 2;
> +
> +     return simple_read_from_buffer(buf, count, ppos, data, rc);
> +}
> +
> +static const struct file_operations ibm_cffps_fops = {
> +     .llseek = noop_llseek,
> +     .read = ibm_cffps_debugfs_op,
> +     .open = simple_open,
> +};
> +
>  static int ibm_cffps_read_byte_data(struct i2c_client *client, int page,
>                                   int reg)
>  {
> @@ -119,7 +271,52 @@ static int ibm_cffps_read_word_data(struct i2c_client 
> *client, int page,
>  static int ibm_cffps_probe(struct i2c_client *client,
>                          const struct i2c_device_id *id)
>  {
> -     return pmbus_do_probe(client, id, &ibm_cffps_info);
> +     int i, rc;
> +     struct dentry *debugfs;
> +     struct ibm_cffps *psu;
> +
> +     rc = pmbus_do_probe(client, id, &ibm_cffps_info);
> +     if (rc)
> +             return rc;
> +
> +     /* Don't fail the probe if we can't create debugfs */
> +     psu = devm_kzalloc(&client->dev, sizeof(*psu), GFP_KERNEL);
> +     if (!psu)
> +             return 0;
> +
> +     psu->client = client;
> +     mutex_init(&psu->input_history.update_lock);
> +     if (jiffies > HZ)
> +             /* time_after wouldn't succeed with last_update = 0 in test */

... but you are setting it to 'jiffies' elsewhere, so it can still end up
being 0 at some point, especially since 'jiffies' starts with a large number
and wraps a few minutes after boot. Not sure I understand the problem,
actually.  Can you elaborate ?

> +             psu->input_history.last_update = jiffies - HZ;
> +
> +     debugfs = pmbus_get_debugfs_dir(client);
> +     if (!debugfs)
> +             return 0;
> +
It might be better to do that first, to avoid allocating memory unnecessarily.
That memory would only be freed when the driver is unloaded.

> +     for (i = 0; i < CFFPS_DEBUGFS_NUM_ENTRIES; ++i)
> +             psu->debugfs_entries[i] = i;
> +
> +     debugfs_create_file("ibm_cffps_input_history", 0444, debugfs,
> +                         &psu->debugfs_entries[CFFPS_DEBUGFS_INPUT_HISTORY],
> +                         &ibm_cffps_fops);
> +     debugfs_create_file("ibm_cffps_fru", 0444, debugfs,
> +                         &psu->debugfs_entries[CFFPS_DEBUGFS_FRU],
> +                         &ibm_cffps_fops);
> +     debugfs_create_file("ibm_cffps_pn", 0444, debugfs,
> +                         &psu->debugfs_entries[CFFPS_DEBUGFS_PN],
> +                         &ibm_cffps_fops);
> +     debugfs_create_file("ibm_cffps_sn", 0444, debugfs,
> +                         &psu->debugfs_entries[CFFPS_DEBUGFS_SN],
> +                         &ibm_cffps_fops);
> +     debugfs_create_file("ibm_cffps_ccin", 0444, debugfs,
> +                         &psu->debugfs_entries[CFFPS_DEBUGFS_CCIN],
> +                         &ibm_cffps_fops);
> +     debugfs_create_file("ibm_cffps_fw", 0444, debugfs,
> +                         &psu->debugfs_entries[CFFPS_DEBUGFS_FW],
> +                         &ibm_cffps_fops);

Can you put those into their own subdirectory ?

        .../ibm_cffps/input_history
        .../ibm_cffps/fru

and so on. Also, consider using ibm_cffps1 (or client->name) to align
with the the hwmon 'name' attribute.

Thanks,
Guenter

> +
> +     return 0;
>  }
>  
>  static const struct i2c_device_id ibm_cffps_id[] = {
> -- 
> 1.8.3.1
> 

Reply via email to