On Mon, Jun 07, 2021 at 10:26:37AM +0200, Jiri Prchal wrote:
> This exports serial number of FRAM in sysfs file named "sernum".
> Formatted in hex, each byte separated by space.
> Example:
> $ cat /sys/class/spi_master/spi0/spi0.0/sernum
> 0000a43644f2ae6c
>
> Signed-off-by: Jiri Prchal <jiri.prchal@xxxxxxxxxxx>
> ---
> v2: no change here
> v3: resend and added more recipients
> v4: resend
> v5: reworked up on Greg comments: no spaces in string, sysfs done correctly
> v6: no change here
> ---
> drivers/misc/eeprom/at25.c | 28 +++++++++++++++++++++++++++-
> 1 file changed, 27 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c
> index 45a486994828..4e4fa8d3ba5d 100644
> --- a/drivers/misc/eeprom/at25.c
> +++ b/drivers/misc/eeprom/at25.c
> @@ -39,6 +39,7 @@ struct at25_data {
> struct nvmem_config nvmem_config;
> struct nvmem_device *nvmem;
> int has_sernum;
> + char *sernum;
> };
>
> #define AT25_WREN 0x06 /* latch the write enable */
> @@ -173,6 +174,25 @@ static int fm25_aux_read(struct at25_data *at25, char *buf, uint8_t command,
> return status;
> }
>
> +static ssize_t sernum_show(struct device *dev, struct device_attribute *attr, char *buf)
> +{
> + struct at25_data *at25;
> + int i;
> +
> + at25 = dev_get_drvdata(dev);
> + for (i = FM25_SN_LEN - 1; i >= 0; i--)
> + buf += sprintf(buf, "%02x", at25->sernum[i]);
> + sprintf(buf, "\n");
Please use sysfs_emit() with the proper print modifier for an array of
bytes in hex (I think there is one...)
> + return (2 * FM25_SN_LEN + 1);
> +}
> +static DEVICE_ATTR(sernum, 0440, sernum_show, NULL);
DEVICE_ATTR_RO() please.
> +
> +static struct attribute *sernum_attrs[] = {
> + &dev_attr_sernum.attr,
> + NULL,
> +};
> +ATTRIBUTE_GROUPS(sernum);
> +
> static int at25_ee_write(void *priv, unsigned int off, void *val, size_t count)
> {
> struct at25_data *at25 = priv;
> @@ -417,8 +437,13 @@ static int at25_probe(struct spi_device *spi)
> else
> at25->chip.flags |= EE_ADDR2;
>
> - if (id[8])
> + if (id[8]) {
> at25->has_sernum = 1;
> + at25->sernum = kzalloc(FM25_SN_LEN, GFP_KERNEL);
Where do you free this memory?
And why does it have to be 0 filled?
thanks,
greg k-h
