rtc: stm32: rework register management to prepare other version of RTC

This patch reworks register/bits management because next version of RTC
uses the same way of working but with different register's offset or bits
moved in new registers.

Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Amelie Delaunay 2018-05-17 14:04:24 +02:00 committed by Alexandre Belloni
parent 819cbde521
commit 02b0cc345c
1 changed files with 127 additions and 57 deletions

View File

@ -16,15 +16,6 @@
#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)
@ -85,7 +76,26 @@
#define RTC_WPR_2ND_KEY 0x53
#define RTC_WPR_WRONG_KEY 0xFF
struct stm32_rtc;
struct stm32_rtc_registers {
u8 tr;
u8 dr;
u8 cr;
u8 isr;
u8 prer;
u8 alrmar;
u8 wpr;
};
struct stm32_rtc_events {
u32 alra;
};
struct stm32_rtc_data {
const struct stm32_rtc_registers regs;
const struct stm32_rtc_events events;
void (*clear_events)(struct stm32_rtc *rtc, unsigned int flags);
bool has_pclk;
bool need_dbp;
};
@ -96,30 +106,35 @@ struct stm32_rtc {
struct regmap *dbp;
unsigned int dbp_reg;
unsigned int dbp_mask;
struct stm32_rtc_data *data;
struct clk *pclk;
struct clk *rtc_ck;
const struct stm32_rtc_data *data;
int irq_alarm;
};
static void stm32_rtc_wpr_unlock(struct stm32_rtc *rtc)
{
writel_relaxed(RTC_WPR_1ST_KEY, rtc->base + STM32_RTC_WPR);
writel_relaxed(RTC_WPR_2ND_KEY, rtc->base + STM32_RTC_WPR);
const struct stm32_rtc_registers *regs = &rtc->data->regs;
writel_relaxed(RTC_WPR_1ST_KEY, rtc->base + regs->wpr);
writel_relaxed(RTC_WPR_2ND_KEY, rtc->base + regs->wpr);
}
static void stm32_rtc_wpr_lock(struct stm32_rtc *rtc)
{
writel_relaxed(RTC_WPR_WRONG_KEY, rtc->base + STM32_RTC_WPR);
const struct stm32_rtc_registers *regs = &rtc->data->regs;
writel_relaxed(RTC_WPR_WRONG_KEY, rtc->base + regs->wpr);
}
static int stm32_rtc_enter_init_mode(struct stm32_rtc *rtc)
{
unsigned int isr = readl_relaxed(rtc->base + STM32_RTC_ISR);
const struct stm32_rtc_registers *regs = &rtc->data->regs;
unsigned int isr = readl_relaxed(rtc->base + regs->isr);
if (!(isr & STM32_RTC_ISR_INITF)) {
isr |= STM32_RTC_ISR_INIT;
writel_relaxed(isr, rtc->base + STM32_RTC_ISR);
writel_relaxed(isr, rtc->base + regs->isr);
/*
* It takes around 2 rtc_ck clock cycles to enter in
@ -128,7 +143,7 @@ static int stm32_rtc_enter_init_mode(struct stm32_rtc *rtc)
* 1MHz, we poll every 10 us with a timeout of 100ms.
*/
return readl_relaxed_poll_timeout_atomic(
rtc->base + STM32_RTC_ISR,
rtc->base + regs->isr,
isr, (isr & STM32_RTC_ISR_INITF),
10, 100000);
}
@ -138,40 +153,50 @@ static int stm32_rtc_enter_init_mode(struct stm32_rtc *rtc)
static void stm32_rtc_exit_init_mode(struct stm32_rtc *rtc)
{
unsigned int isr = readl_relaxed(rtc->base + STM32_RTC_ISR);
const struct stm32_rtc_registers *regs = &rtc->data->regs;
unsigned int isr = readl_relaxed(rtc->base + regs->isr);
isr &= ~STM32_RTC_ISR_INIT;
writel_relaxed(isr, rtc->base + STM32_RTC_ISR);
writel_relaxed(isr, rtc->base + regs->isr);
}
static int stm32_rtc_wait_sync(struct stm32_rtc *rtc)
{
unsigned int isr = readl_relaxed(rtc->base + STM32_RTC_ISR);
const struct stm32_rtc_registers *regs = &rtc->data->regs;
unsigned int isr = readl_relaxed(rtc->base + regs->isr);
isr &= ~STM32_RTC_ISR_RSF;
writel_relaxed(isr, rtc->base + STM32_RTC_ISR);
writel_relaxed(isr, rtc->base + regs->isr);
/*
* Wait for RSF to be set to ensure the calendar registers are
* synchronised, it takes around 2 rtc_ck clock cycles
*/
return readl_relaxed_poll_timeout_atomic(rtc->base + STM32_RTC_ISR,
return readl_relaxed_poll_timeout_atomic(rtc->base + regs->isr,
isr,
(isr & STM32_RTC_ISR_RSF),
10, 100000);
}
static void stm32_rtc_clear_event_flags(struct stm32_rtc *rtc,
unsigned int flags)
{
rtc->data->clear_events(rtc, flags);
}
static irqreturn_t stm32_rtc_alarm_irq(int irq, void *dev_id)
{
struct stm32_rtc *rtc = (struct stm32_rtc *)dev_id;
unsigned int isr, cr;
const struct stm32_rtc_registers *regs = &rtc->data->regs;
const struct stm32_rtc_events *evts = &rtc->data->events;
unsigned int status, cr;
mutex_lock(&rtc->rtc_dev->ops_lock);
isr = readl_relaxed(rtc->base + STM32_RTC_ISR);
cr = readl_relaxed(rtc->base + STM32_RTC_CR);
status = readl_relaxed(rtc->base + regs->isr);
cr = readl_relaxed(rtc->base + regs->cr);
if ((isr & STM32_RTC_ISR_ALRAF) &&
if ((status & evts->alra) &&
(cr & STM32_RTC_CR_ALRAIE)) {
/* Alarm A flag - Alarm interrupt */
dev_dbg(&rtc->rtc_dev->dev, "Alarm occurred\n");
@ -179,9 +204,8 @@ static irqreturn_t stm32_rtc_alarm_irq(int irq, void *dev_id)
/* Pass event to the kernel */
rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF);
/* Clear event flag, otherwise new events won't be received */
writel_relaxed(isr & ~STM32_RTC_ISR_ALRAF,
rtc->base + STM32_RTC_ISR);
/* Clear event flags, otherwise new events won't be received */
stm32_rtc_clear_event_flags(rtc, evts->alra);
}
mutex_unlock(&rtc->rtc_dev->ops_lock);
@ -228,11 +252,12 @@ static void bcd2tm(struct rtc_time *tm)
static int stm32_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct stm32_rtc *rtc = dev_get_drvdata(dev);
const struct stm32_rtc_registers *regs = &rtc->data->regs;
unsigned int tr, dr;
/* Time and Date in BCD format */
tr = readl_relaxed(rtc->base + STM32_RTC_TR);
dr = readl_relaxed(rtc->base + STM32_RTC_DR);
tr = readl_relaxed(rtc->base + regs->tr);
dr = readl_relaxed(rtc->base + regs->dr);
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;
@ -253,6 +278,7 @@ static int stm32_rtc_read_time(struct device *dev, struct rtc_time *tm)
static int stm32_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct stm32_rtc *rtc = dev_get_drvdata(dev);
const struct stm32_rtc_registers *regs = &rtc->data->regs;
unsigned int tr, dr;
int ret = 0;
@ -277,8 +303,8 @@ static int stm32_rtc_set_time(struct device *dev, struct rtc_time *tm)
goto end;
}
writel_relaxed(tr, rtc->base + STM32_RTC_TR);
writel_relaxed(dr, rtc->base + STM32_RTC_DR);
writel_relaxed(tr, rtc->base + regs->tr);
writel_relaxed(dr, rtc->base + regs->dr);
stm32_rtc_exit_init_mode(rtc);
@ -292,12 +318,14 @@ end:
static int stm32_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct stm32_rtc *rtc = dev_get_drvdata(dev);
const struct stm32_rtc_registers *regs = &rtc->data->regs;
const struct stm32_rtc_events *evts = &rtc->data->events;
struct rtc_time *tm = &alrm->time;
unsigned int alrmar, cr, isr;
unsigned int alrmar, cr, status;
alrmar = readl_relaxed(rtc->base + STM32_RTC_ALRMAR);
cr = readl_relaxed(rtc->base + STM32_RTC_CR);
isr = readl_relaxed(rtc->base + STM32_RTC_ISR);
alrmar = readl_relaxed(rtc->base + regs->alrmar);
cr = readl_relaxed(rtc->base + regs->cr);
status = readl_relaxed(rtc->base + regs->isr);
if (alrmar & STM32_RTC_ALRMXR_DATE_MASK) {
/*
@ -350,7 +378,7 @@ static int stm32_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
bcd2tm(tm);
alrm->enabled = (cr & STM32_RTC_CR_ALRAE) ? 1 : 0;
alrm->pending = (isr & STM32_RTC_ISR_ALRAF) ? 1 : 0;
alrm->pending = (status & evts->alra) ? 1 : 0;
return 0;
}
@ -358,9 +386,11 @@ static int stm32_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
static int stm32_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct stm32_rtc *rtc = dev_get_drvdata(dev);
unsigned int isr, cr;
const struct stm32_rtc_registers *regs = &rtc->data->regs;
const struct stm32_rtc_events *evts = &rtc->data->events;
unsigned int cr;
cr = readl_relaxed(rtc->base + STM32_RTC_CR);
cr = readl_relaxed(rtc->base + regs->cr);
stm32_rtc_wpr_unlock(rtc);
@ -369,12 +399,10 @@ static int stm32_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
cr |= (STM32_RTC_CR_ALRAIE | STM32_RTC_CR_ALRAE);
else
cr &= ~(STM32_RTC_CR_ALRAIE | STM32_RTC_CR_ALRAE);
writel_relaxed(cr, rtc->base + STM32_RTC_CR);
writel_relaxed(cr, rtc->base + regs->cr);
/* Clear event flag, otherwise new events won't be received */
isr = readl_relaxed(rtc->base + STM32_RTC_ISR);
isr &= ~STM32_RTC_ISR_ALRAF;
writel_relaxed(isr, rtc->base + STM32_RTC_ISR);
/* Clear event flags, otherwise new events won't be received */
stm32_rtc_clear_event_flags(rtc, evts->alra);
stm32_rtc_wpr_lock(rtc);
@ -383,9 +411,10 @@ static int stm32_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
static int stm32_rtc_valid_alrm(struct stm32_rtc *rtc, struct rtc_time *tm)
{
const struct stm32_rtc_registers *regs = &rtc->data->regs;
int cur_day, cur_mon, cur_year, cur_hour, cur_min, cur_sec;
unsigned int dr = readl_relaxed(rtc->base + STM32_RTC_DR);
unsigned int tr = readl_relaxed(rtc->base + STM32_RTC_TR);
unsigned int dr = readl_relaxed(rtc->base + regs->dr);
unsigned int tr = readl_relaxed(rtc->base + regs->tr);
cur_day = (dr & STM32_RTC_DR_DATE) >> STM32_RTC_DR_DATE_SHIFT;
cur_mon = (dr & STM32_RTC_DR_MONTH) >> STM32_RTC_DR_MONTH_SHIFT;
@ -419,6 +448,7 @@ static int stm32_rtc_valid_alrm(struct stm32_rtc *rtc, struct rtc_time *tm)
static int stm32_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct stm32_rtc *rtc = dev_get_drvdata(dev);
const struct stm32_rtc_registers *regs = &rtc->data->regs;
struct rtc_time *tm = &alrm->time;
unsigned int cr, isr, alrmar;
int ret = 0;
@ -450,15 +480,15 @@ static int stm32_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
stm32_rtc_wpr_unlock(rtc);
/* Disable Alarm */
cr = readl_relaxed(rtc->base + STM32_RTC_CR);
cr = readl_relaxed(rtc->base + regs->cr);
cr &= ~STM32_RTC_CR_ALRAE;
writel_relaxed(cr, rtc->base + STM32_RTC_CR);
writel_relaxed(cr, rtc->base + regs->cr);
/*
* Poll Alarm write flag to be sure that Alarm update is allowed: it
* takes around 2 rtc_ck clock cycles
*/
ret = readl_relaxed_poll_timeout_atomic(rtc->base + STM32_RTC_ISR,
ret = readl_relaxed_poll_timeout_atomic(rtc->base + regs->isr,
isr,
(isr & STM32_RTC_ISR_ALRAWF),
10, 100000);
@ -469,7 +499,7 @@ static int stm32_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
}
/* Write to Alarm register */
writel_relaxed(alrmar, rtc->base + STM32_RTC_ALRMAR);
writel_relaxed(alrmar, rtc->base + regs->alrmar);
if (alrm->enabled)
stm32_rtc_alarm_irq_enable(dev, 1);
@ -490,14 +520,50 @@ static const struct rtc_class_ops stm32_rtc_ops = {
.alarm_irq_enable = stm32_rtc_alarm_irq_enable,
};
static void stm32_rtc_clear_events(struct stm32_rtc *rtc,
unsigned int flags)
{
const struct stm32_rtc_registers *regs = &rtc->data->regs;
/* Flags are cleared by writing 0 in RTC_ISR */
writel_relaxed(readl_relaxed(rtc->base + regs->isr) & ~flags,
rtc->base + regs->isr);
}
static const struct stm32_rtc_data stm32_rtc_data = {
.has_pclk = false,
.need_dbp = true,
.regs = {
.tr = 0x00,
.dr = 0x04,
.cr = 0x08,
.isr = 0x0C,
.prer = 0x10,
.alrmar = 0x1C,
.wpr = 0x24,
},
.events = {
.alra = STM32_RTC_ISR_ALRAF,
},
.clear_events = stm32_rtc_clear_events,
};
static const struct stm32_rtc_data stm32h7_rtc_data = {
.has_pclk = true,
.need_dbp = true,
.regs = {
.tr = 0x00,
.dr = 0x04,
.cr = 0x08,
.isr = 0x0C,
.prer = 0x10,
.alrmar = 0x1C,
.wpr = 0x24,
},
.events = {
.alra = STM32_RTC_ISR_ALRAF,
},
.clear_events = stm32_rtc_clear_events,
};
static const struct of_device_id stm32_rtc_of_match[] = {
@ -510,6 +576,7 @@ MODULE_DEVICE_TABLE(of, stm32_rtc_of_match);
static int stm32_rtc_init(struct platform_device *pdev,
struct stm32_rtc *rtc)
{
const struct stm32_rtc_registers *regs = &rtc->data->regs;
unsigned int prer, pred_a, pred_s, pred_a_max, pred_s_max, cr;
unsigned int rate;
int ret = 0;
@ -550,14 +617,14 @@ static int stm32_rtc_init(struct platform_device *pdev,
}
prer = (pred_s << STM32_RTC_PRER_PRED_S_SHIFT) & STM32_RTC_PRER_PRED_S;
writel_relaxed(prer, rtc->base + STM32_RTC_PRER);
writel_relaxed(prer, rtc->base + regs->prer);
prer |= (pred_a << STM32_RTC_PRER_PRED_A_SHIFT) & STM32_RTC_PRER_PRED_A;
writel_relaxed(prer, rtc->base + STM32_RTC_PRER);
writel_relaxed(prer, rtc->base + regs->prer);
/* Force 24h time format */
cr = readl_relaxed(rtc->base + STM32_RTC_CR);
cr = readl_relaxed(rtc->base + regs->cr);
cr &= ~STM32_RTC_CR_FMT;
writel_relaxed(cr, rtc->base + STM32_RTC_CR);
writel_relaxed(cr, rtc->base + regs->cr);
stm32_rtc_exit_init_mode(rtc);
@ -571,6 +638,7 @@ end:
static int stm32_rtc_probe(struct platform_device *pdev)
{
struct stm32_rtc *rtc;
const struct stm32_rtc_registers *regs;
struct resource *res;
int ret;
@ -585,6 +653,7 @@ static int stm32_rtc_probe(struct platform_device *pdev)
rtc->data = (struct stm32_rtc_data *)
of_device_get_match_data(&pdev->dev);
regs = &rtc->data->regs;
if (rtc->data->need_dbp) {
rtc->dbp = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
@ -688,7 +757,7 @@ static int stm32_rtc_probe(struct platform_device *pdev)
* If INITS flag is reset (calendar year field set to 0x00), calendar
* must be initialized
*/
if (!(readl_relaxed(rtc->base + STM32_RTC_ISR) & STM32_RTC_ISR_INITS))
if (!(readl_relaxed(rtc->base + regs->isr) & STM32_RTC_ISR_INITS))
dev_warn(&pdev->dev, "Date/Time must be initialized\n");
return 0;
@ -708,13 +777,14 @@ err:
static int stm32_rtc_remove(struct platform_device *pdev)
{
struct stm32_rtc *rtc = platform_get_drvdata(pdev);
const struct stm32_rtc_registers *regs = &rtc->data->regs;
unsigned int cr;
/* Disable interrupts */
stm32_rtc_wpr_unlock(rtc);
cr = readl_relaxed(rtc->base + STM32_RTC_CR);
cr = readl_relaxed(rtc->base + regs->cr);
cr &= ~STM32_RTC_CR_ALRAIE;
writel_relaxed(cr, rtc->base + STM32_RTC_CR);
writel_relaxed(cr, rtc->base + regs->cr);
stm32_rtc_wpr_lock(rtc);
clk_disable_unprepare(rtc->rtc_ck);