2021-06-07 16:14:06

by Jiri Prchal

Subject: [PATCH v8 4/5] nvmem: eeprom: at25: export FRAM serial num

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 <[email protected]>
---
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
v7: moved FM25_SN_LEN, static array, used sysfs_emit, DEVICE_ATTR_RO
v8: clarify sysfs_emit format
---
drivers/misc/eeprom/at25.c | 22 +++++++++++++++++++++-
1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c
index e25cec7c474b..4a47a7e2d90d 100644
--- a/drivers/misc/eeprom/at25.c
+++ b/drivers/misc/eeprom/at25.c
@@ -31,6 +31,7 @@
* AT25M02, AT25128B
*/

+#define FM25_SN_LEN 8 /* serial number length */
struct at25_data {
struct spi_device *spi;
struct mutex lock;
@@ -39,6 +40,7 @@ struct at25_data {
struct nvmem_config nvmem_config;
struct nvmem_device *nvmem;
int has_sernum;
+ u8 sernum[FM25_SN_LEN];
};

#define AT25_WREN 0x06 /* latch the write enable */
@@ -172,6 +174,21 @@ static int fm25_aux_read(struct at25_data *at25, u8 *buf, uint8_t command,
return status;
}

+static ssize_t sernum_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct at25_data *at25;
+
+ at25 = dev_get_drvdata(dev);
+ return sysfs_emit(buf, "%*phN\n", sizeof at25->sernum, at25->sernum);
+}
+static DEVICE_ATTR_RO(sernum);
+
+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;
@@ -416,8 +433,10 @@ static int at25_probe(struct spi_device *spi)
else
at25->chip.flags |= EE_ADDR2;

- if (id[8])
+ if (id[8]) {
at25->has_sernum = 1;
+ fm25_aux_read(at25, at25->sernum, FM25_RDSN, FM25_SN_LEN);
+ }
else
at25->has_sernum = 0;

@@ -471,6 +490,7 @@ static struct spi_driver at25_driver = {
.driver = {
.name = "at25",
.of_match_table = at25_of_match,
+ .dev_groups = sernum_groups,
},
.probe = at25_probe,
};
--
2.25.1

2021-06-08 09:07:31

by Greg Kroah-Hartman

Subject: Re: [PATCH v8 4/5] nvmem: eeprom: at25: export FRAM serial num

On Mon, Jun 07, 2021 at 06:12:00PM +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 <[email protected]>
> ---
> 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
> v7: moved FM25_SN_LEN, static array, used sysfs_emit, DEVICE_ATTR_RO
> v8: clarify sysfs_emit format
> ---
> drivers/misc/eeprom/at25.c | 22 +++++++++++++++++++++-
> 1 file changed, 21 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c
> index e25cec7c474b..4a47a7e2d90d 100644
> --- a/drivers/misc/eeprom/at25.c
> +++ b/drivers/misc/eeprom/at25.c
> @@ -31,6 +31,7 @@
> * AT25M02, AT25128B
> */
>
> +#define FM25_SN_LEN 8 /* serial number length */
> struct at25_data {
> struct spi_device *spi;
> struct mutex lock;
> @@ -39,6 +40,7 @@ struct at25_data {
> struct nvmem_config nvmem_config;
> struct nvmem_device *nvmem;
> int has_sernum;
> + u8 sernum[FM25_SN_LEN];
> };
>
> #define AT25_WREN 0x06 /* latch the write enable */
> @@ -172,6 +174,21 @@ static int fm25_aux_read(struct at25_data *at25, u8 *buf, uint8_t command,
> return status;
> }
>
> +static ssize_t sernum_show(struct device *dev, struct device_attribute *attr, char *buf)
> +{
> + struct at25_data *at25;
> +
> + at25 = dev_get_drvdata(dev);
> + return sysfs_emit(buf, "%*phN\n", sizeof at25->sernum, at25->sernum);

sizeof(at25->sernum) is the normal way to write this.

thanks,

greg k-h