Quoting Mike Looijmans (2020-11-03 06:17:41)
> Export an attribute program_nvm_bank that when read reports the current
> bank value. To program the chip's current state into NVM, write the
> magic value 0xC7 into this attribute.
>
> Signed-off-by: Mike Looijmans <mike.looijm...@topic.nl>
> ---
Any chance this can be done through the nvmem framework?
> drivers/clk/clk-si5341.c | 73 ++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 73 insertions(+)
>
> diff --git a/drivers/clk/clk-si5341.c b/drivers/clk/clk-si5341.c
> index e0446e66fa64..4e025a5ea2b7 100644
> --- a/drivers/clk/clk-si5341.c
> +++ b/drivers/clk/clk-si5341.c
> @@ -1199,6 +1205,69 @@ static const struct regmap_config si5341_regmap_config
> = {
> .volatile_table = &si5341_regmap_volatile,
> };
>
> +static ssize_t program_nvm_bank_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct i2c_client *client = to_i2c_client(dev);
> + struct clk_si5341 *data = i2c_get_clientdata(client);
> + unsigned int regval;
> + int ret;
> +
> + ret = regmap_read(data->regmap, SI5341_ACTIVE_NVM_BANK, ®val);
> + if (ret)
> + return ret;
> +
> + return sprintf(buf, "%#x\n", regval);
> +}
> +
> +static ssize_t program_nvm_bank_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf,
> + size_t count)
> +{
> + struct clk_si5341 *data = i2c_get_clientdata(to_i2c_client(dev));
> + int ret;
> + unsigned int value;
> + unsigned int timeout;
> +
> + ret = kstrtouint(buf, 0, &value);
> + if (ret < 0)
> + return ret;
> +
> + /* Write the magic value to this attribute to program the NVM */
> + if (value != SI5341_SI5341_NVM_WRITE_COOKIE)
> + return -EINVAL;
> +
> + ret = regmap_write(data->regmap, SI5341_NVM_WRITE,
> + SI5341_SI5341_NVM_WRITE_COOKIE);
> + if (ret)
> + return ret;
> +
> + /* Wait for SI5341_DEVICE_READY register to become 0x0f */
> + for (timeout = 10000; timeout; --timeout) {
> + ret = regmap_read(data->regmap, SI5341_DEVICE_READY, &value);
This is regmap_read_poll_timeout()?
> + if (ret)
> + return ret;
> +
> + if (value == 0x0f)
> + break;
> + }
> +
> + return count;
> +}
> +
> +static DEVICE_ATTR_RW(program_nvm_bank);
> +
> +static struct attribute *si5341_sysfs_entries[] = {
> + &dev_attr_program_nvm_bank.attr,
> + NULL,
> +};
> +
> +static struct attribute_group si5341_attr_group = {
> + .name = NULL, /* put in device directory */
> + .attrs = si5341_sysfs_entries,
> +};
If not nvmem framework, then this needs to be documented in
Documentation/ABI/
> +
> static int si5341_dt_parse_dt(struct i2c_client *client,
> struct clk_si5341_output_config *config)
> {
> @@ -1544,6 +1613,10 @@ static int si5341_probe(struct i2c_client *client,
> for (i = 0; i < data->num_synth; ++i)
> devm_kfree(&client->dev, (void *)synth_clock_names[i]);
>
> + err = sysfs_create_group(&client->dev.kobj, &si5341_attr_group);
> + if (err)
> + dev_err(&client->dev, "failed to create sysfs entries\n");
> +
Cool, I as a user would do what in this situation? The error message
seems sort of worthless.
