From b41c23e152f2852ff7a299676af4f642bbe94abf Mon Sep 17 00:00:00 2001 From: Giulio Benetti Date: Wed, 25 Jul 2018 19:26:05 +0200 Subject: 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: Giulio Benetti Signed-off-by: Alexandre Belloni --- drivers/rtc/rtc-ds1307.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 92 insertions(+) (limited to 'drivers/rtc/rtc-ds1307.c') diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c index 8268813f15c3..edccd0c0da25 100644 --- a/drivers/rtc/rtc-ds1307.c +++ b/drivers/rtc/rtc-ds1307.c @@ -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", -- cgit