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SubjectRe: [PATCH v9 4/4] rtc: ds1307: add frequency_test_enable sysfs attribute to check tick on m41txx
On Wed, Jul 18, 2018 at 12:40 PM, Giulio Benetti
<giulio.benetti@micronovasrl.com> wrote:
> On m41txx you can enable open-drain OUT pin to check if offset is ok.
> Enabling OUT pin with frequency_test_enable attribute, OUT pin will tick
> 512 times faster than 1s tick base.
>
> Enable or Disable FT bit on CONTROL register if freq_test is 1 or 0.

> +static ssize_t frequency_test_enable_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct ds1307 *ds1307 = dev_get_drvdata(dev);


> + bool freq_test_en = 0;

First of all, initialization of boolean using int is not very best style.
Second, this is not needed.

> + int ret;
> +
> + ret = kstrtobool(buf, &freq_test_en);

> + if (ret == -EINVAL) {

What kind of other error code you may expect and why they are not
considered as no error?

> + dev_err(dev, "Failed to store RTC Frequency Test attribute\n");
> + return ret;
> + }
> +
> + regmap_update_bits(ds1307->regmap, M41TXX_REG_CONTROL, M41TXX_BIT_FT,
> + freq_test_en ? M41TXX_BIT_FT : 0);
> +
> + return count;
> +}
> +
> +static ssize_t frequency_test_enable_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + struct ds1307 *ds1307 = dev_get_drvdata(dev);
> + unsigned int ctrl_reg;
> +
> + regmap_read(ds1307->regmap, M41TXX_REG_CONTROL, &ctrl_reg);
> +

> + if (ctrl_reg & M41TXX_BIT_FT)
> + return scnprintf(buf, PAGE_SIZE, "on\n");
> + else
> + return scnprintf(buf, PAGE_SIZE, "off\n");

Entire condition might be one line.

> +}
> +

> +static int ds1307_add_frequency_test(struct ds1307 *ds1307)
> +{

> + int err = 0;

Redundant assignment. See below.

> +
> + switch (ds1307->type) {
> + case m41t0:
> + case m41t00:
> + case m41t11:
> + /* Export sysfs entries */
> + err = sysfs_create_group(&(ds1307->dev)->kobj,
> + &rtc_freq_test_attr_group);
> + if (err) {
> + dev_err(ds1307->dev,
> + "Failed to create sysfs group: %d\n",
> + err);
> + return err;
> + }
> +
> + err = devm_add_action_or_reset(ds1307->dev,
> + rtc_calib_remove_sysfs_group,
> + ds1307->dev);
> + if (err) {
> + dev_err(ds1307->dev,
> + "Failed to add sysfs cleanup action: %d\n",
> + err);
> + sysfs_remove_group(&(ds1307->dev)->kobj,
> + &rtc_freq_test_attr_group);
> + return err;
> + }
> + break;
> + default:
> + break;
> + }
> +

> + return err;

return 0;

--
With Best Regards,
Andy Shevchenko

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