Commit b41c23e1 authored by Giulio Benetti's avatar Giulio Benetti Committed by Alexandre Belloni
Browse files

rtc: ds1307: add frequency_test_enable attribute on m41txx 



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.

Signed-off-by: default avatarGiulio Benetti <giulio.benetti@micronovasrl.com>
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent 79230ff6

drivers/rtc/rtc-ds1307.c

+92 −0
Original line number Diff line number Diff line
@@ -1050,6 +1050,94 @@ static int m41txx_rtc_set_offset(struct device *dev, long offset) 
				  ctrl_reg);

}



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;

	int ret;



	ret = kstrtobool(buf, &freq_test_en);

	if (ret) {

		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);



	return scnprintf(buf, PAGE_SIZE, (ctrl_reg & M41TXX_BIT_FT) ? "on\n" :

			"off\n");

}



static DEVICE_ATTR_RW(frequency_test_enable);



static struct attribute *rtc_freq_test_attrs[] = {

	&dev_attr_frequency_test_enable.attr,

	NULL,

};



static const struct attribute_group rtc_freq_test_attr_group = {

	.attrs		= rtc_freq_test_attrs,

};



static void rtc_calib_remove_sysfs_group(void *_dev)

{

	struct device *dev = _dev;



	sysfs_remove_group(&dev->kobj, &rtc_freq_test_attr_group);

}



static int ds1307_add_frequency_test(struct ds1307 *ds1307)

{

	int err;



	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 0;

}



/*----------------------------------------------------------------------*/



static int ds1307_nvram_read(void *priv, unsigned int offset, void *val,
@@ -1792,6 +1880,10 @@ read_rtc: 
	if (err)

		return err;



	err = ds1307_add_frequency_test(ds1307);

	if (err)

		return err;



	if (chip->nvram_size) {

		struct nvmem_config nvmem_cfg = {

			.name = "ds1307_nvram",

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