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From: Giulio Benetti <giulio.benetti@micronovasrl.com>
To: a.zummo@towertech.it, alexandre.belloni@bootlin.com
Cc: robh+dt@kernel.org, mark.rutland@arm.com,
	linux-rtc@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, andy.shevchenko@gmail.com,
	Giulio Benetti <giulio.benetti@micronovasrl.com>
Subject: [PATCH v6 4/4] rtc: ds1307: add frequency_test_enable sysfs attribute to check tick on m41txx
Date: Wed, 16 May 2018 23:07:05 +0200	[thread overview]
Message-ID: <20180516210705.5824-4-giulio.benetti@micronovasrl.com> (raw)
In-Reply-To: <20180516210705.5824-1-giulio.benetti@micronovasrl.com>

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: Giulio Benetti <giulio.benetti@micronovasrl.com>
---
 drivers/rtc/rtc-ds1307.c | 96 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 96 insertions(+)

diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index 2797d01bfa1d..b2e87845d860 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -1053,6 +1053,96 @@ 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 = 0;
+	int ret;
+
+	ret = kstrtobool(buf, &freq_test_en);
+	if (ret == -EINVAL) {
+		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");
+}
+
+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 = 0;
+
+	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;
+}
+
 /*----------------------------------------------------------------------*/
 
 static int ds1307_nvram_read(void *priv, unsigned int offset, void *val,
@@ -1794,6 +1884,12 @@ static int ds1307_probe(struct i2c_client *client,
 	if (err)
 		return err;
 
+	err = ds1307_add_frequency_test(ds1307);
+	if (err) {
+		rtc_device_unregister(ds1307->rtc);
+		return err;
+	}
+
 	if (chip->nvram_size) {
 		struct nvmem_config nvmem_cfg = {
 			.name = "ds1307_nvram",
-- 
2.17.0

  parent reply	other threads:[~2018-05-16 21:07 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-16 21:07 [PATCH v6 1/4] rtc: ds1307: fix data pointer to m41t0 Giulio Benetti
2018-05-16 21:07 ` [PATCH v6 2/4] rtc: ds1307: support m41t11 variant Giulio Benetti
2018-05-16 21:07 ` [PATCH v6 3/4] rtc: ds1307: add offset sysfs for mt41txx chips Giulio Benetti
2018-05-16 21:07 ` Giulio Benetti [this message]
2018-05-16 21:09   ` [PATCH v6 4/4] rtc: ds1307: add frequency_test_enable sysfs attribute to check tick on m41txx Giulio Benetti
2018-05-16 21:08 [PATCH v6 1/4] rtc: ds1307: fix data pointer to m41t0 Giulio Benetti
2018-05-16 21:08 ` [PATCH v6 4/4] rtc: ds1307: add frequency_test_enable sysfs attribute to check tick on m41txx Giulio Benetti

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