From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.bootlin.com ([62.4.15.54]:50932 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752568AbeEJVqv (ORCPT ); Thu, 10 May 2018 17:46:51 -0400 Date: Thu, 10 May 2018 23:46:49 +0200 From: Alexandre Belloni To: Giulio Benetti Cc: a.zummo@towertech.it, robh+dt@kernel.org, mark.rutland@arm.com, linux-rtc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 4/4] rtc: ds1307: add freq_test sysfs attribute to check tick on m41txx Message-ID: <20180510214649.GR10960@piout.net> References: <20180509193355.49466-1-giulio.benetti@micronovasrl.com> <20180509193355.49466-4-giulio.benetti@micronovasrl.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20180509193355.49466-4-giulio.benetti@micronovasrl.com> Sender: linux-rtc-owner@vger.kernel.org List-ID: On 09/05/2018 21:33:55+0200, Giulio Benetti wrote: > On m41txx you can enable open-drain OUT pin to check if offset is ok. > Enabling OUT pin with freq_test 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 > --- > V2 => V3: export freq_test on sysfs only if supported(m41txx series) > > drivers/rtc/rtc-ds1307.c | 107 +++++++++++++++++++++++++++++++++++++++ > 1 file changed, 107 insertions(+) > > diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c > index 33895668b363..79206bf21018 100644 > --- a/drivers/rtc/rtc-ds1307.c > +++ b/drivers/rtc/rtc-ds1307.c > @@ -1042,6 +1042,109 @@ static int m41txx_rtc_set_offset(struct device *dev, long offset) > return regmap_write(ds1307->regmap, M41TXX_REG_CONTROL, ctrl_reg); > } > > +static ssize_t freq_test_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, size_t count) > +{ > + struct ds1307 *ds1307 = dev_get_drvdata(dev); > + unsigned long freq_test = 0; > + unsigned int ctrl_reg; > + int retval; > + > + retval = kstrtoul(buf, 10, &freq_test); > + if ((retval < 0) || (retval > 1)) { > + dev_err(dev, "Failed to store RTC Frequency Test attribute\n"); > + return -EINVAL; > + } > + > + regmap_read(ds1307->regmap, M41TXX_REG_CONTROL, &ctrl_reg); > + > + if (freq_test) > + ctrl_reg |= M41TXX_BIT_FT; > + else > + ctrl_reg &= ~M41TXX_BIT_FT; > + > + retval = regmap_write(ds1307->regmap, M41TXX_REG_CONTROL, ctrl_reg); > + Pleas use regmap_update_bits > + return retval ? retval : count; > +} > + > +static ssize_t freq_test_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct ds1307 *ds1307 = dev_get_drvdata(dev); > + int freq_test = 0; > + unsigned int ctrl_reg; > + > + regmap_read(ds1307->regmap, M41TXX_REG_CONTROL, &ctrl_reg); > + > + if (ctrl_reg & M41TXX_BIT_FT) > + freq_test = true; > + else > + freq_test = false; > + > + if ((freq_test < 0) || (freq_test > 1)) { This will never happen > + dev_err(dev, "Failed to read RTC Frequency Test\n"); > + sprintf(buf, "0\n"); > + return freq_test; > + } > + > + return sprintf(buf, "%d\n", freq_test); > +} > + > +static DEVICE_ATTR_RW(freq_test); I'd prefer the file to be named frequency_test_enable > + > +static struct attribute *rtc_freq_test_attrs[] = { > + &dev_attr_freq_test.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); You need to sysfs_remove_group here > + return err; > + } > + break; > + default: > + break; > + } > + > + return err; > +} > + > /*----------------------------------------------------------------------*/ > > static int ds1307_nvram_read(void *priv, unsigned int offset, void *val, > @@ -1783,6 +1886,10 @@ static int ds1307_probe(struct i2c_client *client, > 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", > -- > 2.17.0 > -- Alexandre Belloni, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com