| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <295836ac-4f04-f384-14fc-95685cac77b2@st.com>
Date: Mon, 5 Dec 2016 10:45:06 +0100
From: Amelie DELAUNAY <amelie.delaunay@...com>
To: Mathieu Poirier <mathieu.poirier@...aro.org>
CC: "a.zummo@...ertech.it" <a.zummo@...ertech.it>,
"alexandre.belloni@...e-electrons.com"
<alexandre.belloni@...e-electrons.com>,
"robh+dt@...nel.org" <robh+dt@...nel.org>,
"mark.rutland@....com" <mark.rutland@....com>,
"mcoquelin.stm32@...il.com" <mcoquelin.stm32@...il.com>,
Alexandre TORGUE <alexandre.torgue@...com>,
"linux@...linux.org.uk" <linux@...linux.org.uk>,
"rtc-linux@...glegroups.com" <rtc-linux@...glegroups.com>,
"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
"linux-arm-kernel@...ts.infradead.org"
<linux-arm-kernel@...ts.infradead.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
Gabriel FERNANDEZ <gabriel.fernandez@...com>
Subject: Re: [PATCH 3/8] rtc: add STM32 RTC driver
On 12/02/2016 07:05 PM, Mathieu Poirier wrote:
> On Fri, Dec 02, 2016 at 03:09:56PM +0100, Amelie Delaunay wrote:
>> This patch adds support for the STM32 RTC.
>>
>> Signed-off-by: Amelie Delaunay <amelie.delaunay@...com>
>> ---
>> drivers/rtc/Kconfig | 10 +
>> drivers/rtc/Makefile | 1 +
>> drivers/rtc/rtc-stm32.c | 777 ++++++++++++++++++++++++++++++++++++++++++++++++
>> 3 files changed, 788 insertions(+)
>> create mode 100644 drivers/rtc/rtc-stm32.c
>>
>> diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
>> index e859d14..dd8b218 100644
>> --- a/drivers/rtc/Kconfig
>> +++ b/drivers/rtc/Kconfig
>> @@ -1706,6 +1706,16 @@ config RTC_DRV_PIC32
>> This driver can also be built as a module. If so, the module
>> will be called rtc-pic32
>>
>> +config RTC_DRV_STM32
>> + tristate "STM32 On-Chip RTC"
>> + depends on ARCH_STM32
>> + help
>> + If you say yes here you get support for the STM32 On-Chip
>> + Real Time Clock.
>> +
>> + This driver can also be built as a module, if so, the module
>> + will be called "rtc-stm32".
>> +
>> comment "HID Sensor RTC drivers"
>>
>> config RTC_DRV_HID_SENSOR_TIME
>> diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
>> index 1ac694a..87bd9cc 100644
>> --- a/drivers/rtc/Makefile
>> +++ b/drivers/rtc/Makefile
>> @@ -144,6 +144,7 @@ obj-$(CONFIG_RTC_DRV_SNVS) += rtc-snvs.o
>> obj-$(CONFIG_RTC_DRV_SPEAR) += rtc-spear.o
>> obj-$(CONFIG_RTC_DRV_STARFIRE) += rtc-starfire.o
>> obj-$(CONFIG_RTC_DRV_STK17TA8) += rtc-stk17ta8.o
>> +obj-$(CONFIG_RTC_DRV_STM32) += rtc-stm32.o
>> obj-$(CONFIG_RTC_DRV_STMP) += rtc-stmp3xxx.o
>> obj-$(CONFIG_RTC_DRV_ST_LPC) += rtc-st-lpc.o
>> obj-$(CONFIG_RTC_DRV_SUN4V) += rtc-sun4v.o
>> diff --git a/drivers/rtc/rtc-stm32.c b/drivers/rtc/rtc-stm32.c
>> new file mode 100644
>> index 0000000..9e710ff
>> --- /dev/null
>> +++ b/drivers/rtc/rtc-stm32.c
>> @@ -0,0 +1,777 @@
>> +/*
>> + * Copyright (C) Amelie Delaunay 2015
>> + * Author: Amelie Delaunay <adelaunay.stm32@...il.com>
>> + * License terms: GNU General Public License (GPL), version 2
>> + */
>> +
>> +#include <linux/bcd.h>
>> +#include <linux/clk.h>
>> +#include <linux/init.h>
>> +#include <linux/io.h>
>> +#include <linux/iopoll.h>
>> +#include <linux/ioport.h>
>> +#include <linux/kernel.h>
>> +#include <linux/mfd/syscon.h>
>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/of_device.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/regmap.h>
>> +#include <linux/rtc.h>
>> +#include <linux/spinlock.h>
>> +
>> +#define DRIVER_NAME "stm32_rtc"
>> +
>> +/* STM32 RTC registers */
>> +#define STM32_RTC_TR 0x00
>> +#define STM32_RTC_DR 0x04
>> +#define STM32_RTC_CR 0x08
>> +#define STM32_RTC_ISR 0x0C
>> +#define STM32_RTC_PRER 0x10
>> +#define STM32_RTC_ALRMAR 0x1C
>> +#define STM32_RTC_WPR 0x24
>> +
>> +/* STM32_RTC_TR bit fields */
>> +#define STM32_RTC_TR_SEC_SHIFT 0
>> +#define STM32_RTC_TR_SEC GENMASK(6, 0)
>> +#define STM32_RTC_TR_MIN_SHIFT 8
>> +#define STM32_RTC_TR_MIN GENMASK(14, 8)
>> +#define STM32_RTC_TR_HOUR_SHIFT 16
>> +#define STM32_RTC_TR_HOUR GENMASK(21, 16)
>> +
>> +/* STM32_RTC_DR bit fields */
>> +#define STM32_RTC_DR_DATE_SHIFT 0
>> +#define STM32_RTC_DR_DATE GENMASK(5, 0)
>> +#define STM32_RTC_DR_MONTH_SHIFT 8
>> +#define STM32_RTC_DR_MONTH GENMASK(11, 8)
>> +#define STM32_RTC_DR_WDAY_SHIFT 13
>> +#define STM32_RTC_DR_WDAY GENMASK(15, 13)
>> +#define STM32_RTC_DR_YEAR_SHIFT 16
>> +#define STM32_RTC_DR_YEAR GENMASK(23, 16)
>> +
>> +/* STM32_RTC_CR bit fields */
>> +#define STM32_RTC_CR_FMT BIT(6)
>> +#define STM32_RTC_CR_ALRAE BIT(8)
>> +#define STM32_RTC_CR_ALRAIE BIT(12)
>> +
>> +/* STM32_RTC_ISR bit fields */
>> +#define STM32_RTC_ISR_ALRAWF BIT(0)
>> +#define STM32_RTC_ISR_INITS BIT(4)
>> +#define STM32_RTC_ISR_RSF BIT(5)
>> +#define STM32_RTC_ISR_INITF BIT(6)
>> +#define STM32_RTC_ISR_INIT BIT(7)
>> +#define STM32_RTC_ISR_ALRAF BIT(8)
>> +
>> +/* STM32_RTC_PRER bit fields */
>> +#define STM32_RTC_PRER_PRED_S_SHIFT 0
>> +#define STM32_RTC_PRER_PRED_S GENMASK(14, 0)
>> +#define STM32_RTC_PRER_PRED_A_SHIFT 16
>> +#define STM32_RTC_PRER_PRED_A GENMASK(22, 16)
>> +
>> +/* STM32_RTC_ALRMAR and STM32_RTC_ALRMBR bit fields */
>> +#define STM32_RTC_ALRMXR_SEC_SHIFT 0
>> +#define STM32_RTC_ALRMXR_SEC GENMASK(6, 0)
>> +#define STM32_RTC_ALRMXR_SEC_MASK BIT(7)
>> +#define STM32_RTC_ALRMXR_MIN_SHIFT 8
>> +#define STM32_RTC_ALRMXR_MIN GENMASK(14, 8)
>> +#define STM32_RTC_ALRMXR_MIN_MASK BIT(15)
>> +#define STM32_RTC_ALRMXR_HOUR_SHIFT 16
>> +#define STM32_RTC_ALRMXR_HOUR GENMASK(21, 16)
>> +#define STM32_RTC_ALRMXR_PM BIT(22)
>> +#define STM32_RTC_ALRMXR_HOUR_MASK BIT(23)
>> +#define STM32_RTC_ALRMXR_DATE_SHIFT 24
>> +#define STM32_RTC_ALRMXR_DATE GENMASK(29, 24)
>> +#define STM32_RTC_ALRMXR_WDSEL BIT(30)
>> +#define STM32_RTC_ALRMXR_WDAY_SHIFT 24
>> +#define STM32_RTC_ALRMXR_WDAY GENMASK(27, 24)
>> +#define STM32_RTC_ALRMXR_DATE_MASK BIT(31)
>> +
>> +/* STM32_RTC_WPR key constants */
>> +#define RTC_WPR_1ST_KEY 0xCA
>> +#define RTC_WPR_2ND_KEY 0x53
>> +#define RTC_WPR_WRONG_KEY 0xFF
>> +
>> +/*
>> + * RTC registers are protected agains parasitic write access.
>> + * PWR_CR_DBP bit must be set to enable write access to RTC registers.
>> + */
>> +/* STM32_PWR_CR */
>> +#define PWR_CR 0x00
>> +/* STM32_PWR_CR bit field */
>> +#define PWR_CR_DBP BIT(8)
>> +
>> +static struct regmap *dbp;
>> +
>> +struct stm32_rtc {
>> + struct rtc_device *rtc_dev;
>> + void __iomem *base;
>> + struct clk *pclk;
>> + struct clk *ck_rtc;
>> + unsigned int clksrc;
>> + spinlock_t lock; /* Protects registers accesses */
>> + int irq_alarm;
>> + struct regmap *pwrcr;
>> +};
>
> One more thing... What did you want to do with pclk, clksrc and pwrcr? They
> aren't used in the driver. If this is for future enhancement I suggest you
> introduce those when you submit the patches.
You're right.
>
>> +
>> +static inline unsigned int stm32_rtc_readl(struct stm32_rtc *rtc,
>> + unsigned int offset)
>> +{
>> + return readl_relaxed(rtc->base + offset);
>> +}
>> +
>> +static inline void stm32_rtc_writel(struct stm32_rtc *rtc,
>> + unsigned int offset, unsigned int value)
>> +{
>> + writel_relaxed(value, rtc->base + offset);
>> +}
>> +
>> +static void stm32_rtc_wpr_unlock(struct stm32_rtc *rtc)
>> +{
>> +// if (dbp)
>> +// regmap_update_bits(dbp, PWR_CR, PWR_CR_DBP, PWR_CR_DBP);
>> +
>> + stm32_rtc_writel(rtc, STM32_RTC_WPR, RTC_WPR_1ST_KEY);
>> + stm32_rtc_writel(rtc, STM32_RTC_WPR, RTC_WPR_2ND_KEY);
>> +}
>> +
>> +static void stm32_rtc_wpr_lock(struct stm32_rtc *rtc)
>> +{
>> + stm32_rtc_writel(rtc, STM32_RTC_WPR, RTC_WPR_WRONG_KEY);
>> +
>> +// if (dbp)
>> +// regmap_update_bits(dbp, PWR_CR, PWR_CR_DBP, ~PWR_CR_DBP);
>> +}
>> +
>> +static int stm32_rtc_enter_init_mode(struct stm32_rtc *rtc)
>> +{
>> + unsigned int isr = stm32_rtc_readl(rtc, STM32_RTC_ISR);
>> +
>> + if (!(isr & STM32_RTC_ISR_INITF)) {
>> + isr |= STM32_RTC_ISR_INIT;
>> + stm32_rtc_writel(rtc, STM32_RTC_ISR, isr);
>> +
>> + return readl_relaxed_poll_timeout_atomic(
>> + rtc->base + STM32_RTC_ISR,
>> + isr, (isr & STM32_RTC_ISR_INITF),
>> + 10, 100000);
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static void stm32_rtc_exit_init_mode(struct stm32_rtc *rtc)
>> +{
>> + unsigned int isr = stm32_rtc_readl(rtc, STM32_RTC_ISR);
>> +
>> + isr &= ~STM32_RTC_ISR_INIT;
>> + stm32_rtc_writel(rtc, STM32_RTC_ISR, isr);
>> +}
>> +
>> +static int stm32_rtc_wait_sync(struct stm32_rtc *rtc)
>> +{
>> + unsigned int isr;
>> +
>> + isr = stm32_rtc_readl(rtc, STM32_RTC_ISR);
>> +
>> + isr &= ~STM32_RTC_ISR_RSF;
>> + stm32_rtc_writel(rtc, STM32_RTC_ISR, isr);
>> +
>> + /* Wait the registers to be synchronised */
>> + return readl_relaxed_poll_timeout_atomic(rtc->base + STM32_RTC_ISR,
>> + isr,
>> + (isr & STM32_RTC_ISR_RSF),
>> + 10, 100000);
>> +}
>> +
>> +static irqreturn_t stm32_rtc_alarm_irq(int irq, void *dev_id)
>> +{
>> + struct stm32_rtc *rtc = (struct stm32_rtc *)dev_id;
>> + unsigned long irqflags, events = 0;
>> + unsigned int isr, cr;
>> +
>> + spin_lock_irqsave(&rtc->lock, irqflags);
>> +
>> + isr = stm32_rtc_readl(rtc, STM32_RTC_ISR);
>> + cr = stm32_rtc_readl(rtc, STM32_RTC_CR);
>> +
>> + if ((isr & STM32_RTC_ISR_ALRAF) &&
>> + (cr & STM32_RTC_CR_ALRAIE)) {
>> + /* Alarm A flag - Alarm interrupt */
>> + events |= RTC_IRQF | RTC_AF;
>> + isr &= ~STM32_RTC_ISR_ALRAF;
>> + }
>> +
>> + /* Clear event irqflags, otherwise new events won't be received */
>> + stm32_rtc_writel(rtc, STM32_RTC_ISR, isr);
>> +
>> + spin_unlock_irqrestore(&rtc->lock, irqflags);
>> +
>> + if (events) {
>> + dev_info(&rtc->rtc_dev->dev, "Alarm occurred\n");
>> +
>> + /* Pass event to the kernel */
>> + rtc_update_irq(rtc->rtc_dev, 1, events);
>> + return IRQ_HANDLED;
>> + } else {
>> + return IRQ_NONE;
>> + }
>> +}
>> +
>> +/* Convert rtc_time structure from bin to bcd format */
>> +static void tm2bcd(struct rtc_time *tm)
>> +{
>> + tm->tm_sec = bin2bcd(tm->tm_sec);
>> + tm->tm_min = bin2bcd(tm->tm_min);
>> + tm->tm_hour = bin2bcd(tm->tm_hour);
>> +
>> + tm->tm_mday = bin2bcd(tm->tm_mday);
>> + tm->tm_mon = bin2bcd(tm->tm_mon + 1);
>> + tm->tm_year = bin2bcd(tm->tm_year - 100);
>> + /*
>> + * Number of days since Sunday
>> + * - on kernel side, 0=Sunday...6=Saturday
>> + * - on rtc side, 0=invalid,1=Monday...7=Sunday
>> + */
>> + tm->tm_wday = (!tm->tm_wday) ? 7 : tm->tm_wday;
>> +}
>> +
>> +/* Convert rtc_time structure from bcd to bin format */
>> +static void bcd2tm(struct rtc_time *tm)
>> +{
>> + tm->tm_sec = bcd2bin(tm->tm_sec);
>> + tm->tm_min = bcd2bin(tm->tm_min);
>> + tm->tm_hour = bcd2bin(tm->tm_hour);
>> +
>> + tm->tm_mday = bcd2bin(tm->tm_mday);
>> + tm->tm_mon = bcd2bin(tm->tm_mon) - 1;
>> + tm->tm_year = bcd2bin(tm->tm_year) + 100;
>> + /*
>> + * Number of days since Sunday
>> + * - on kernel side, 0=Sunday...6=Saturday
>> + * - on rtc side, 0=invalid,1=Monday...7=Sunday
>> + */
>> + tm->tm_wday %= 7;
>> +}
>> +
>> +static int stm32_rtc_read_time(struct device *dev, struct rtc_time *tm)
>> +{
>> + struct stm32_rtc *rtc = dev_get_drvdata(dev);
>> + unsigned int tr, dr;
>> + unsigned long irqflags;
>> +
>> + spin_lock_irqsave(&rtc->lock, irqflags);
>> +
>> + /* Time and Date in BCD format */
>> + tr = stm32_rtc_readl(rtc, STM32_RTC_TR);
>> + dr = stm32_rtc_readl(rtc, STM32_RTC_DR);
>> +
>> + spin_unlock_irqrestore(&rtc->lock, irqflags);
>> +
>> + tm->tm_sec = (tr & STM32_RTC_TR_SEC) >> STM32_RTC_TR_SEC_SHIFT;
>> + tm->tm_min = (tr & STM32_RTC_TR_MIN) >> STM32_RTC_TR_MIN_SHIFT;
>> + tm->tm_hour = (tr & STM32_RTC_TR_HOUR) >> STM32_RTC_TR_HOUR_SHIFT;
>> +
>> + tm->tm_mday = (dr & STM32_RTC_DR_DATE) >> STM32_RTC_DR_DATE_SHIFT;
>> + tm->tm_mon = (dr & STM32_RTC_DR_MONTH) >> STM32_RTC_DR_MONTH_SHIFT;
>> + tm->tm_year = (dr & STM32_RTC_DR_YEAR) >> STM32_RTC_DR_YEAR_SHIFT;
>> + tm->tm_wday = (dr & STM32_RTC_DR_WDAY) >> STM32_RTC_DR_WDAY_SHIFT;
>> +
>> + /* We don't report tm_yday and tm_isdst */
>> +
>> + bcd2tm(tm);
>> +
>> + if (rtc_valid_tm(tm) < 0) {
>> + dev_err(dev, "%s: rtc_time is not valid.\n", __func__);
>> + return -EINVAL;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int stm32_rtc_set_time(struct device *dev, struct rtc_time *tm)
>> +{
>> + struct stm32_rtc *rtc = dev_get_drvdata(dev);
>> + unsigned int tr, dr;
>> + unsigned long irqflags;
>> + int ret = 0;
>> +
>> + if (rtc_valid_tm(tm) < 0) {
>> + dev_err(dev, "%s: rtc_time is not valid.\n", __func__);
>> + return -EINVAL;
>> + }
>> +
>> + tm2bcd(tm);
>> +
>> + /* Time in BCD format */
>> + tr = ((tm->tm_sec << STM32_RTC_TR_SEC_SHIFT) & STM32_RTC_TR_SEC) |
>> + ((tm->tm_min << STM32_RTC_TR_MIN_SHIFT) & STM32_RTC_TR_MIN) |
>> + ((tm->tm_hour << STM32_RTC_TR_HOUR_SHIFT) & STM32_RTC_TR_HOUR);
>> +
>> + /* Date in BCD format */
>> + dr = ((tm->tm_mday << STM32_RTC_DR_DATE_SHIFT) & STM32_RTC_DR_DATE) |
>> + ((tm->tm_mon << STM32_RTC_DR_MONTH_SHIFT) & STM32_RTC_DR_MONTH) |
>> + ((tm->tm_year << STM32_RTC_DR_YEAR_SHIFT) & STM32_RTC_DR_YEAR) |
>> + ((tm->tm_wday << STM32_RTC_DR_WDAY_SHIFT) & STM32_RTC_DR_WDAY);
>> +
>> + spin_lock_irqsave(&rtc->lock, irqflags);
>> +
>> + stm32_rtc_wpr_unlock(rtc);
>> +
>> + ret = stm32_rtc_enter_init_mode(rtc);
>> + if (ret) {
>> + dev_err(dev, "Can't enter in init mode. Set time aborted.\n");
>> + goto end;
>> + }
>> +
>> + stm32_rtc_writel(rtc, STM32_RTC_TR, tr);
>> + stm32_rtc_writel(rtc, STM32_RTC_DR, dr);
>> +
>> + stm32_rtc_exit_init_mode(rtc);
>> +
>> + ret = stm32_rtc_wait_sync(rtc);
>> +end:
>> + stm32_rtc_wpr_lock(rtc);
>> +
>> + spin_unlock_irqrestore(&rtc->lock, irqflags);
>> +
>> + return ret;
>> +}
>> +
>> +static int stm32_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
>> +{
>> + struct stm32_rtc *rtc = dev_get_drvdata(dev);
>> + struct rtc_time *tm = &alrm->time;
>> + unsigned int alrmar, cr, isr;
>> + unsigned long irqflags;
>> +
>> + spin_lock_irqsave(&rtc->lock, irqflags);
>> +
>> + alrmar = stm32_rtc_readl(rtc, STM32_RTC_ALRMAR);
>> + cr = stm32_rtc_readl(rtc, STM32_RTC_CR);
>> + isr = stm32_rtc_readl(rtc, STM32_RTC_ISR);
>> +
>> + spin_unlock_irqrestore(&rtc->lock, irqflags);
>> +
>> + if (alrmar & STM32_RTC_ALRMXR_DATE_MASK) {
>> + /*
>> + * Date/day don't care in Alarm comparison so alarm triggers
>> + * every day
>> + */
>> + tm->tm_mday = -1;
>> + tm->tm_wday = -1;
>> + } else {
>> + if (alrmar & STM32_RTC_ALRMXR_WDSEL) {
>> + /* Alarm is set to a day of week */
>> + tm->tm_mday = -1;
>> + tm->tm_wday = (alrmar & STM32_RTC_ALRMXR_WDAY) >>
>> + STM32_RTC_ALRMXR_WDAY_SHIFT;
>> + tm->tm_wday %= 7;
>> + } else {
>> + /* Alarm is set to a day of month */
>> + tm->tm_wday = -1;
>> + tm->tm_mday = (alrmar & STM32_RTC_ALRMXR_DATE) >>
>> + STM32_RTC_ALRMXR_DATE_SHIFT;
>> + }
>> + }
>> +
>> + if (alrmar & STM32_RTC_ALRMXR_HOUR_MASK) {
>> + /* Hours don't care in Alarm comparison */
>> + tm->tm_hour = -1;
>> + } else {
>> + tm->tm_hour = (alrmar & STM32_RTC_ALRMXR_HOUR) >>
>> + STM32_RTC_ALRMXR_HOUR_SHIFT;
>> + if (alrmar & STM32_RTC_ALRMXR_PM)
>> + tm->tm_hour += 12;
>> + }
>> +
>> + if (alrmar & STM32_RTC_ALRMXR_MIN_MASK) {
>> + /* Minutes don't care in Alarm comparison */
>> + tm->tm_min = -1;
>> + } else {
>> + tm->tm_min = (alrmar & STM32_RTC_ALRMXR_MIN) >>
>> + STM32_RTC_ALRMXR_MIN_SHIFT;
>> + }
>> +
>> + if (alrmar & STM32_RTC_ALRMXR_SEC_MASK) {
>> + /* Seconds don't care in Alarm comparison */
>> + tm->tm_sec = -1;
>> + } else {
>> + tm->tm_sec = (alrmar & STM32_RTC_ALRMXR_SEC) >>
>> + STM32_RTC_ALRMXR_SEC_SHIFT;
>> + }
>> +
>> + bcd2tm(tm);
>> +
>> + alrm->enabled = (cr & STM32_RTC_CR_ALRAE) ? 1 : 0;
>> + alrm->pending = (isr & STM32_RTC_ISR_ALRAF) ? 1 : 0;
>> +
>> + return 0;
>> +}
>> +
>> +static int stm32_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
>> +{
>> + struct stm32_rtc *rtc = dev_get_drvdata(dev);
>> + unsigned long irqflags;
>> + unsigned int isr, cr;
>> +
>> + cr = stm32_rtc_readl(rtc, STM32_RTC_CR);
>> +
>> + spin_lock_irqsave(&rtc->lock, irqflags);
>> +
>> + stm32_rtc_wpr_unlock(rtc);
>> +
>> + /* We expose Alarm A to the kernel */
>> + if (enabled)
>> + cr |= (STM32_RTC_CR_ALRAIE | STM32_RTC_CR_ALRAE);
>> + else
>> + cr &= ~(STM32_RTC_CR_ALRAIE | STM32_RTC_CR_ALRAE);
>> + stm32_rtc_writel(rtc, STM32_RTC_CR, cr);
>> +
>> + /* Clear event irqflags, otherwise new events won't be received */
>> + isr = stm32_rtc_readl(rtc, STM32_RTC_ISR);
>> + isr &= ~STM32_RTC_ISR_ALRAF;
>> + stm32_rtc_writel(rtc, STM32_RTC_ISR, isr);
>> +
>> + stm32_rtc_wpr_lock(rtc);
>> +
>> + spin_unlock_irqrestore(&rtc->lock, irqflags);
>> +
>> + return 0;
>> +}
>> +
>> +static int stm32_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
>> +{
>> + struct stm32_rtc *rtc = dev_get_drvdata(dev);
>> + struct rtc_time *tm = &alrm->time;
>> + unsigned long irqflags;
>> + unsigned int cr, isr, alrmar;
>> + int ret = 0;
>> +
>> + if (rtc_valid_tm(tm)) {
>> + dev_err(dev, "Alarm time not valid.\n");
>> + return -EINVAL;
>> + }
>> +
>> + tm2bcd(tm);
>> +
>> + spin_lock_irqsave(&rtc->lock, irqflags);
>> +
>> + stm32_rtc_wpr_unlock(rtc);
>> +
>> + /* Disable Alarm */
>> + cr = stm32_rtc_readl(rtc, STM32_RTC_CR);
>> + cr &= ~STM32_RTC_CR_ALRAE;
>> + stm32_rtc_writel(rtc, STM32_RTC_CR, cr);
>> +
>> + /* Poll Alarm write flag to be sure that Alarm update is allowed */
>> + ret = readl_relaxed_poll_timeout_atomic(rtc->base + STM32_RTC_ISR,
>> + isr,
>> + (isr & STM32_RTC_ISR_ALRAWF),
>> + 10, 100);
>> +
>> + if (ret) {
>> + dev_err(dev, "Alarm update not allowed\n");
>> + goto end;
>> + }
>> +
>> + alrmar = 0;
>> +
>> + if (tm->tm_mday < 0 && tm->tm_wday < 0) {
>> + /*
>> + * Date/day don't care in Alarm comparison so alarm triggers
>> + * every day
>> + */
>> + alrmar |= STM32_RTC_ALRMXR_DATE_MASK;
>> + } else {
>> + if (tm->tm_mday > 0) {
>> + /* Date is selected (ignoring wday) */
>> + alrmar |= (tm->tm_mday << STM32_RTC_ALRMXR_DATE_SHIFT) &
>> + STM32_RTC_ALRMXR_DATE;
>> + } else {
>> + /* Day of week is selected */
>> + int wday = (tm->tm_wday == 0) ? 7 : tm->tm_wday;
>> +
>> + alrmar |= STM32_RTC_ALRMXR_WDSEL;
>> + alrmar |= (wday << STM32_RTC_ALRMXR_WDAY_SHIFT) &
>> + STM32_RTC_ALRMXR_WDAY;
>> + }
>> + }
>> +
>> + if (tm->tm_hour < 0) {
>> + /* Hours don't care in Alarm comparison */
>> + alrmar |= STM32_RTC_ALRMXR_HOUR_MASK;
>> + } else {
>> + /* 24-hour format */
>> + alrmar &= ~STM32_RTC_ALRMXR_PM;
>> + alrmar |= (tm->tm_hour << STM32_RTC_ALRMXR_HOUR_SHIFT) &
>> + STM32_RTC_ALRMXR_HOUR;
>> + }
>> +
>> + if (tm->tm_min < 0) {
>> + /* Minutes don't care in Alarm comparison */
>> + alrmar |= STM32_RTC_ALRMXR_MIN_MASK;
>> + } else {
>> + alrmar |= (tm->tm_min << STM32_RTC_ALRMXR_MIN_SHIFT) &
>> + STM32_RTC_ALRMXR_MIN;
>> + }
>> +
>> + if (tm->tm_sec < 0) {
>> + /* Seconds don't care in Alarm comparison */
>> + alrmar |= STM32_RTC_ALRMXR_SEC_MASK;
>> + } else {
>> + alrmar |= (tm->tm_sec << STM32_RTC_ALRMXR_SEC_SHIFT) &
>> + STM32_RTC_ALRMXR_SEC;
>> + }
>> +
>> + /* Write to Alarm register */
>> + stm32_rtc_writel(rtc, STM32_RTC_ALRMAR, alrmar);
>> +
>> + if (alrm->enabled)
>> + stm32_rtc_alarm_irq_enable(dev, 1);
>> + else
>> + stm32_rtc_alarm_irq_enable(dev, 0);
>> +
>> +end:
>> + stm32_rtc_wpr_lock(rtc);
>> +
>> + spin_unlock_irqrestore(&rtc->lock, irqflags);
>> +
>> + return ret;
>> +}
>> +
>> +static const struct rtc_class_ops stm32_rtc_ops = {
>> + .read_time = stm32_rtc_read_time,
>> + .set_time = stm32_rtc_set_time,
>> + .read_alarm = stm32_rtc_read_alarm,
>> + .set_alarm = stm32_rtc_set_alarm,
>> + .alarm_irq_enable = stm32_rtc_alarm_irq_enable,
>> +};
>> +
>> +#ifdef CONFIG_OF
>> +static const struct of_device_id stm32_rtc_of_match[] = {
>> + { .compatible = "st,stm32-rtc" },
>> + {}
>> +};
>> +MODULE_DEVICE_TABLE(of, stm32_rtc_of_match);
>> +#endif
>> +
>> +static int stm32_rtc_init(struct platform_device *pdev,
>> + struct stm32_rtc *rtc)
>> +{
>> + unsigned int prer, pred_a, pred_s, pred_a_max, pred_s_max, cr;
>> + unsigned int rate;
>> + unsigned long irqflags;
>> + int ret = 0;
>> +
>> + rate = clk_get_rate(rtc->ck_rtc);
>> +
>> + /* Find prediv_a and prediv_s to obtain the 1Hz calendar clock */
>> + pred_a_max = STM32_RTC_PRER_PRED_A >> STM32_RTC_PRER_PRED_A_SHIFT;
>> + pred_s_max = STM32_RTC_PRER_PRED_S >> STM32_RTC_PRER_PRED_S_SHIFT;
>> +
>> + for (pred_a = pred_a_max; pred_a >= 0; pred_a--) {
>> + pred_s = (rate / (pred_a + 1)) - 1;
>> +
>> + if (((pred_s + 1) * (pred_a + 1)) == rate)
>> + break;
>> + }
>> +
>> + /*
>> + * Can't find a 1Hz, so give priority to RTC power consumption
>> + * by choosing the higher possible value for prediv_a
>> + */
>> + if ((pred_s > pred_s_max) || (pred_a > pred_a_max)) {
>> + pred_a = pred_a_max;
>> + pred_s = (rate / (pred_a + 1)) - 1;
>> +
>> + dev_warn(&pdev->dev, "ck_rtc is %s\n",
>> + (rate - ((pred_a + 1) * (pred_s + 1)) < 0) ?
>> + "fast" : "slow");
>> + }
>> +
>> + spin_lock_irqsave(&rtc->lock, irqflags);
>> +
>> + stm32_rtc_wpr_unlock(rtc);
>> +
>> + ret = stm32_rtc_enter_init_mode(rtc);
>> + if (ret) {
>> + dev_err(&pdev->dev,
>> + "Can't enter in init mode. Prescaler config failed.\n");
>> + goto end;
>> + }
>> +
>> + prer = (pred_s << STM32_RTC_PRER_PRED_S_SHIFT) & STM32_RTC_PRER_PRED_S;
>> + stm32_rtc_writel(rtc, STM32_RTC_PRER, prer);
>> + prer |= (pred_a << STM32_RTC_PRER_PRED_A_SHIFT) & STM32_RTC_PRER_PRED_A;
>> + stm32_rtc_writel(rtc, STM32_RTC_PRER, prer);
>> +
>> + /* Force 24h time format */
>> + cr = stm32_rtc_readl(rtc, STM32_RTC_CR);
>> + cr &= ~STM32_RTC_CR_FMT;
>> + stm32_rtc_writel(rtc, STM32_RTC_CR, cr);
>> +
>> + stm32_rtc_exit_init_mode(rtc);
>> +
>> + ret = stm32_rtc_wait_sync(rtc);
>> +
>> + if (stm32_rtc_readl(rtc, STM32_RTC_ISR) & STM32_RTC_ISR_INITS)
>> + dev_warn(&pdev->dev, "Date/Time must be initialized\n");
>> +end:
>> + stm32_rtc_wpr_lock(rtc);
>> +
>> + spin_unlock_irqrestore(&rtc->lock, irqflags);
>> +
>> + return ret;
>> +}
>> +
>> +static int stm32_rtc_probe(struct platform_device *pdev)
>> +{
>> + struct stm32_rtc *rtc;
>> + struct resource *res;
>> + int ret;
>> +
>> + rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
>> + if (!rtc)
>> + return -ENOMEM;
>> +
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + rtc->base = devm_ioremap_resource(&pdev->dev, res);
>> + if (IS_ERR(rtc->base))
>> + return PTR_ERR(rtc->base);
>> +
>> + dbp = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "st,syscfg");
>> + if (IS_ERR(dbp)) {
>> + dev_err(&pdev->dev, "no st,syscfg\n");
>> + return PTR_ERR(dbp);
>> + }
>> +
>> + spin_lock_init(&rtc->lock);
>> +
>> + rtc->ck_rtc = devm_clk_get(&pdev->dev, "ck_rtc");
>> + if (IS_ERR(rtc->ck_rtc)) {
>> + dev_err(&pdev->dev, "no ck_rtc clock");
>> + return PTR_ERR(rtc->ck_rtc);
>> + }
>> +
>> + ret = clk_prepare_enable(rtc->ck_rtc);
>> + if (ret)
>> + return ret;
>> +
>> + if (dbp)
>> + regmap_update_bits(dbp, PWR_CR, PWR_CR_DBP, PWR_CR_DBP);
>> +
>> + ret = stm32_rtc_init(pdev, rtc);
>> + if (ret)
>> + goto err;
>> +
>> + rtc->irq_alarm = platform_get_irq_byname(pdev, "alarm");
>> + if (rtc->irq_alarm <= 0) {
>> + dev_err(&pdev->dev, "no alarm irq\n");
>> + ret = -ENOENT;
>> + goto err;
>> + }
>> +
>> + platform_set_drvdata(pdev, rtc);
>> +
>> + device_init_wakeup(&pdev->dev, true);
>> +
>> + rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, pdev->name,
>> + &stm32_rtc_ops, THIS_MODULE);
>> + if (IS_ERR(rtc->rtc_dev)) {
>> + ret = PTR_ERR(rtc->rtc_dev);
>> + dev_err(&pdev->dev, "rtc device registration failed, err=%d\n",
>> + ret);
>> + goto err;
>> + }
>> +
>> + /* Handle RTC alarm interrupts */
>> + ret = devm_request_irq(&pdev->dev, rtc->irq_alarm,
>> + stm32_rtc_alarm_irq, IRQF_TRIGGER_RISING,
>> + dev_name(&rtc->rtc_dev->dev), rtc);
>> + if (ret) {
>> + dev_err(&pdev->dev, "IRQ%d (alarm interrupt) already claimed\n",
>> + rtc->irq_alarm);
>> + goto err;
>> + }
>> +
>> + return 0;
>> +err:
>> + clk_disable_unprepare(rtc->ck_rtc);
>> +
>> + if (dbp)
>> + regmap_update_bits(dbp, PWR_CR, PWR_CR_DBP, ~PWR_CR_DBP);
>> +
>> + device_init_wakeup(&pdev->dev, false);
>> +
>> + return ret;
>> +}
>> +
>> +static int __exit stm32_rtc_remove(struct platform_device *pdev)
>> +{
>> + struct stm32_rtc *rtc = platform_get_drvdata(pdev);
>> + unsigned int cr;
>> +
>> + /* Disable interrupts */
>> + stm32_rtc_wpr_unlock(rtc);
>> + cr = stm32_rtc_readl(rtc, STM32_RTC_CR);
>> + cr &= ~STM32_RTC_CR_ALRAIE;
>> + stm32_rtc_writel(rtc, STM32_RTC_CR, cr);
>> + stm32_rtc_wpr_lock(rtc);
>> +
>> + clk_disable_unprepare(rtc->ck_rtc);
>> +
>> + /* Enable backup domain write protection */
>> + if (dbp)
>> + regmap_update_bits(dbp, PWR_CR, PWR_CR_DBP, ~PWR_CR_DBP);
>> +
>> + device_init_wakeup(&pdev->dev, false);
>> +
>> + return 0;
>> +}
>> +
>> +#ifdef CONFIG_PM_SLEEP
>> +static int stm32_rtc_suspend(struct device *dev)
>> +{
>> + struct stm32_rtc *rtc = dev_get_drvdata(dev);
>> +
>> + if (device_may_wakeup(dev))
>> + return enable_irq_wake(rtc->irq_alarm);
>> +
>> + return 0;
>> +}
>> +
>> +static int stm32_rtc_resume(struct device *dev)
>> +{
>> + struct stm32_rtc *rtc = dev_get_drvdata(dev);
>> + int ret = 0;
>> +
>> + ret = stm32_rtc_wait_sync(rtc);
>> + if (ret < 0)
>> + return ret;
>> +
>> + if (device_may_wakeup(dev))
>> + return disable_irq_wake(rtc->irq_alarm);
>> +
>> + return ret;
>> +}
>> +#endif
>> +
>> +static SIMPLE_DEV_PM_OPS(stm32_rtc_pm_ops,
>> + stm32_rtc_suspend, stm32_rtc_resume);
>> +
>> +static struct platform_driver stm32_rtc_driver = {
>> + .probe = stm32_rtc_probe,
>> + .remove = stm32_rtc_remove,
>> + .driver = {
>> + .name = DRIVER_NAME,
>> + .pm = &stm32_rtc_pm_ops,
>> + .of_match_table = stm32_rtc_of_match,
>> + },
>> +};
>> +
>> +module_platform_driver(stm32_rtc_driver);
>> +
>> +MODULE_ALIAS("platform:" DRIVER_NAME);
>> +MODULE_AUTHOR("Amelie Delaunay <amelie.delaunay@...com>");
>> +MODULE_DESCRIPTION("STMicroelectronics STM32 Real Time Clock driver");
>> +MODULE_LICENSE("GPL v2");
>> --
>> 1.9.1
>>
Best regards,
Amelie
Powered by blists - more mailing lists