From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751696AbdECGKz (ORCPT ); Wed, 3 May 2017 02:10:55 -0400 Received: from fllnx210.ext.ti.com ([198.47.19.17]:55296 "EHLO fllnx210.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751014AbdECGKs (ORCPT ); Wed, 3 May 2017 02:10:48 -0400 Subject: Re: [PATCH] RTC: Add functionality to read/write rtc scratch registers To: , References: <1492492807-20316-1-git-send-email-j-keerthy@ti.com> CC: , , , Russ Dill From: Keerthy Message-ID: <8b28ca13-9822-4172-95b0-59802187ec93@ti.com> Date: Wed, 3 May 2017 11:39:34 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.7.0 MIME-Version: 1.0 In-Reply-To: <1492492807-20316-1-git-send-email-j-keerthy@ti.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday 18 April 2017 10:50 AM, Keerthy wrote: > From: Russ Dill > > Many RTCs provide scratch registers that are maintained so long as the RTC > has power. Provide a generic method to access these registers. > A gentle ping on this > Signed-off-by: Russ Dill > Signed-off-by: Keerthy > --- > drivers/rtc/interface.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++++ > drivers/rtc/rtc-omap.c | 35 ++++++++++++++++++++++++++++++++++ > include/linux/rtc.h | 7 +++++++ > 3 files changed, 92 insertions(+) > > diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c > index fc0fa75..facde06 100644 > --- a/drivers/rtc/interface.c > +++ b/drivers/rtc/interface.c > @@ -1016,3 +1016,53 @@ int rtc_set_offset(struct rtc_device *rtc, long offset) > mutex_unlock(&rtc->ops_lock); > return ret; > } > + > +/* rtc_read_scratch - Read from RTC scratch register > + * @ rtc: rtc device to be used > + * @ index: index of scratch register > + * @ value: returned value read > + * > + * Kernel interface read from an RTC scratch register > + */ > +int rtc_read_scratch(struct rtc_device *rtc, unsigned int index, u32 *value) > +{ > + int err; > + > + mutex_lock(&rtc->ops_lock); > + if (!rtc->ops) > + err = -ENODEV; > + else if (index >= rtc->ops->scratch_size || !rtc->ops->read_scratch) > + err = -EINVAL; > + else > + err = rtc->ops->read_scratch(rtc->dev.parent, index, value); > + mutex_unlock(&rtc->ops_lock); > + return err; > +} > +EXPORT_SYMBOL_GPL(rtc_read_scratch); > + > +/* rtc_write_scratch - Write to RTC scratch register > + * @ rtc: rtc device to be used > + * @ index: index of scratch register > + * @ value: value to write > + * > + * Kernel interface write to an RTC scratch register > + */ > +int rtc_write_scratch(struct rtc_device *rtc, unsigned int index, u32 value) > +{ > + int err; > + > + mutex_lock(&rtc->ops_lock); > + > + if (!rtc->ops) > + err = -ENODEV; > + else if (index >= rtc->ops->scratch_size || > + !rtc->ops->write_scratch) > + err = -EINVAL; > + else > + err = rtc->ops->write_scratch(rtc->dev.parent, index, value); > + > + mutex_unlock(&rtc->ops_lock); > + > + return err; > +} > +EXPORT_SYMBOL_GPL(rtc_write_scratch); > diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c > index 13f7cd1..c90d93e 100644 > --- a/drivers/rtc/rtc-omap.c > +++ b/drivers/rtc/rtc-omap.c > @@ -70,6 +70,10 @@ > #define OMAP_RTC_COMP_MSB_REG 0x50 > #define OMAP_RTC_OSC_REG 0x54 > > +#define OMAP_RTC_SCRATCH0_REG 0x60 > +#define OMAP_RTC_SCRATCH1_REG 0x64 > +#define OMAP_RTC_SCRATCH2_REG 0x68 > + > #define OMAP_RTC_KICK0_REG 0x6c > #define OMAP_RTC_KICK1_REG 0x70 > > @@ -414,6 +418,34 @@ static int omap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) > > static struct omap_rtc *omap_rtc_power_off_rtc; > > +static const u32 omap_rtc_scratch_regs[] = { > + OMAP_RTC_SCRATCH0_REG, > + OMAP_RTC_SCRATCH1_REG, > + OMAP_RTC_SCRATCH2_REG, > +}; > + > +static int omap_rtc_read_scratch(struct device *dev, unsigned int index, > + u32 *value) > +{ > + *value = readl(omap_rtc_power_off_rtc->base + > + omap_rtc_scratch_regs[index]); > + > + return 0; > +} > + > +static int omap_rtc_write_scratch(struct device *dev, unsigned int index, > + u32 value) > +{ > + struct omap_rtc *rtc = dev_get_drvdata(dev); > + > + rtc->type->unlock(rtc); > + writel(value, omap_rtc_power_off_rtc->base + > + omap_rtc_scratch_regs[index]); > + rtc->type->lock(rtc); > + > + return 0; > +} > + > /* > * omap_rtc_poweroff: RTC-controlled power off > * > @@ -484,6 +516,9 @@ static void omap_rtc_power_off(void) > .read_alarm = omap_rtc_read_alarm, > .set_alarm = omap_rtc_set_alarm, > .alarm_irq_enable = omap_rtc_alarm_irq_enable, > + .read_scratch = omap_rtc_read_scratch, > + .write_scratch = omap_rtc_write_scratch, > + .scratch_size = ARRAY_SIZE(omap_rtc_scratch_regs), > }; > > static const struct omap_rtc_device_type omap_rtc_default_type = { > diff --git a/include/linux/rtc.h b/include/linux/rtc.h > index b693ada..da5e003 100644 > --- a/include/linux/rtc.h > +++ b/include/linux/rtc.h > @@ -91,6 +91,10 @@ struct rtc_class_ops { > int (*alarm_irq_enable)(struct device *, unsigned int enabled); > int (*read_offset)(struct device *, long *offset); > int (*set_offset)(struct device *, long offset); > + int (*read_scratch)(struct device *, unsigned int, u32*); > + int (*write_scratch)(struct device *, unsigned int, u32); > + > + unsigned int scratch_size; > }; > > #define RTC_DEVICE_NAME_SIZE 20 > @@ -214,6 +218,9 @@ int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer, > int rtc_set_offset(struct rtc_device *rtc, long offset); > void rtc_timer_do_work(struct work_struct *work); > > +int rtc_read_scratch(struct rtc_device *rtc, unsigned int index, u32 *value); > +int rtc_write_scratch(struct rtc_device *rtc, unsigned int index, u32 value); > + > static inline bool is_leap_year(unsigned int year) > { > return (!(year % 4) && (year % 100)) || !(year % 400); >