// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) STMicroelectronics 2017
* Author: Amelie Delaunay <amelie.delaunay@st.com>
*/
#include <linux/bcd.h>
#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/errno.h>
#include <linux/iopoll.h>
#include <linux/ioport.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinconf-generic.h>
#include <linux/pinctrl/pinmux.h>
#include <linux/platform_device.h>
#include <linux/pm_wakeirq.h>
#include <linux/regmap.h>
#include <linux/rtc.h>
#define DRIVER_NAME "stm32_rtc"
/* 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(12, 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)
#define STM32_RTC_CR_OSEL GENMASK(22, 21)
#define STM32_RTC_CR_OSEL_ALARM_A FIELD_PREP(STM32_RTC_CR_OSEL, 0x01)
#define STM32_RTC_CR_COE BIT(23)
#define STM32_RTC_CR_TAMPOE BIT(26)
#define STM32_RTC_CR_TAMPALRM_TYPE BIT(30)
#define STM32_RTC_CR_OUT2EN BIT(31)
/* STM32_RTC_ISR/STM32_RTC_ICSR 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_SR/_SCR bit fields */
#define STM32_RTC_SR_ALRA BIT(0)
/* STM32_RTC_CFGR bit fields */
#define STM32_RTC_CFGR_OUT2_RMP BIT(0)
#define STM32_RTC_CFGR_LSCOEN GENMASK(2, 1)
#define STM32_RTC_CFGR_LSCOEN_OUT1 1
#define STM32_RTC_CFGR_LSCOEN_OUT2_RMP 2
/* STM32_RTC_VERR bit fields */
#define STM32_RTC_VERR_MINREV_SHIFT 0
#define STM32_RTC_VERR_MINREV GENMASK(3, 0)
#define STM32_RTC_VERR_MAJREV_SHIFT 4
#define STM32_RTC_VERR_MAJREV GENMASK(7, 4)
/* STM32_RTC_SECCFGR bit fields */
#define STM32_RTC_SECCFGR 0x20
#define STM32_RTC_SECCFGR_ALRA_SEC BIT(0)
#define STM32_RTC_SECCFGR_INIT_SEC BIT(14)
#define STM32_RTC_SECCFGR_SEC BIT(15)
/* STM32_RTC_RXCIDCFGR bit fields */
#define STM32_RTC_RXCIDCFGR(x) (0x80 + 0x4 * (x))
#define STM32_RTC_RXCIDCFGR_CFEN BIT(0)
#define STM32_RTC_RXCIDCFGR_CID GENMASK(6, 4)
#define STM32_RTC_RXCIDCFGR_CID1 1
/* STM32_RTC_WPR key constants */
#define RTC_WPR_1ST_KEY 0xCA
#define RTC_WPR_2ND_KEY 0x53
#define RTC_WPR_WRONG_KEY 0xFF
/* Max STM32 RTC register offset is 0x3FC */
#define UNDEF_REG 0xFFFF
/* STM32 RTC driver time helpers */
#define SEC_PER_DAY (24 * 60 * 60)
/* STM32 RTC pinctrl helpers */
#define STM32_RTC_PINMUX(_name, _action, ...) { \
.name = (_name), \
.action = (_action), \
.groups = ((const char *[]){ __VA_ARGS__ }), \
.num_groups = ARRAY_SIZE(((const char *[]){ __VA_ARGS__ })), \
}
struct stm32_rtc;
struct stm32_rtc_registers {
u16 tr;
u16 dr;
u16 cr;
u16 isr;
u16 prer;
u16 alrmar;
u16 wpr;
u16 sr;
u16 scr;
u16 cfgr;
u16 verr;
};
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;
bool need_accuracy;
bool rif_protected;
bool has_lsco;
bool has_alarm_out;
};
struct stm32_rtc {
struct rtc_device *rtc_dev;
void __iomem *base;
struct regmap *dbp;
unsigned int dbp_reg;
unsigned int dbp_mask;
struct clk *pclk;
struct clk *rtc_ck;
const struct stm32_rtc_data *data;
int irq_alarm;
struct clk *clk_lsco;
};
struct stm32_rtc_rif_resource {
unsigned int num;
u32 bit;
};
static const struct stm32_rtc_rif_resource STM32_RTC_RES_ALRA = {0, STM32_RTC_SECCFGR_ALRA_SEC};
static const struct stm32_rtc_rif_resource STM32_RTC_RES_INIT = {5, STM32_RTC_SECCFGR_INIT_SEC};
static void stm32_rtc_wpr_unlock(struct stm32_rtc *rtc)
{
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)
{
const struct stm32_rtc_registers *regs = &rtc->data->regs;
writel_relaxed(RTC_WPR_WRONG_KEY, rtc->base + regs->wpr);
}
enum stm32_rtc_pin_name {
NONE,
OUT1,
OUT2,
OUT2_RMP
};
static const struct pinctrl_pin_desc stm32_rtc_pinctrl_pins[] = {
PINCTRL_PIN(OUT1, "out1"),
PINCTRL_PIN(OUT2, "out2"),
PINCTRL_PIN(OUT2_RMP, "out2_rmp"),
};
static int stm32_rtc_pinctrl_get_groups_count(struct pinctrl_dev *pctldev)
{
return ARRAY_SIZE(stm32_rtc_pinctrl_pins);
}
static const char *stm32_rtc_pinctrl_get_group_name(struct pinctrl_dev *pctldev,
unsigned int selector)
{
return stm32_rtc_pinctrl_pins[selector].name;
}
static int stm32_rtc_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
unsigned int selector,
const unsigned int **pins,
unsigned int *num_pins)
{
*pins = &stm32_rtc_pinctrl_pins[selector].number;
*num_pins = 1;
return 0;
}
static const struct pinctrl_ops stm32_rtc_pinctrl_ops = {
.dt_node_to_map = pinconf_generic_dt_node_to_map_all,
.dt_free_map = pinconf_generic_dt_free_map,
.get_groups_count = stm32_rtc_pinctrl_get_groups_count,
.get_group_name = stm32_rtc_pinctrl_get_group_name,
.get_group_pins = stm32_rtc_pinctrl_get_group_pins,
};
struct stm32_rtc_pinmux_func {
const char *name;
const char * const *groups;
const unsigned int num_groups;
int (*action)(struct pinctrl_dev *pctl_dev, unsigned int pin);
};
static int stm32_rtc_pinmux_action_alarm(struct pinctrl_dev *pctldev, unsigned int pin)
{
struct stm32_rtc *rtc = pinctrl_dev_get_drvdata(pctldev);
struct stm32_rtc_registers regs = rtc->data->regs;
unsigned int cr = readl_relaxed(rtc->base + regs.cr);
unsigned int cfgr = readl_relaxed(rtc->base + regs.cfgr);
if (!rtc->data->has_alarm_out)
return -EPERM;
cr &= ~STM32_RTC_CR_OSEL;
cr |= STM32_RTC_CR_OSEL_ALARM_A;
cr &= ~STM32_RTC_CR_TAMPOE;
cr &= ~STM32_RTC_CR_COE;
cr &= ~STM32_RTC_CR_TAMPALRM_TYPE;
switch (pin) {
case OUT1:
cr &= ~STM32_RTC_CR_OUT2EN;
cfgr &= ~STM32_RTC_CFGR_OUT2_RMP;
break;
case OUT2:
cr |= STM32_RTC_CR_OUT2EN;
cfgr &= ~STM32_RTC_CFGR_OUT2_RMP;
break;
case OUT2_RMP:
cr |= STM32_RTC_CR_OUT2EN;
cfgr |= STM32_RTC_CFGR_OUT2_RMP;
break;
default:
return -EINVAL;
}
stm32_rtc_wpr_unlock(rtc);
writel_relaxed(cr, rtc->base + regs.cr);
writel_relaxed(cfgr, rtc->base + regs.cfgr);
stm32_rtc_wpr_lock(rtc);
return 0;
}
static int stm32_rtc_pinmux_lsco_available(struct pinctrl_dev *pctldev, unsigned int pin)
{
struct stm32_rtc *rtc = pinctrl_dev_get_drvdata(pctldev);
struct stm32_rtc_registers regs = rtc->data->regs;
unsigned int cr = readl_relaxed(rtc->base + regs.cr);
unsigned int cfgr = readl_relaxed(rtc->base + regs.cfgr);
unsigned int calib = STM32_RTC_CR_COE;
unsigned int tampalrm = STM32_RTC_CR_TAMPOE | STM32_RTC_CR_OSEL;
switch (pin) {
case OUT1:
if ((!(cr & STM32_RTC_CR_OUT2EN) &&
((cr & calib) || cr & tampalrm)) ||
((cr & calib) && (cr & tampalrm)))
return -EBUSY;
break;
case OUT2_RMP:
if ((cr & STM32_RTC_CR_OUT2EN) &&
(cfgr & STM32_RTC_CFGR_OUT2_RMP) &&
((cr & calib) || (cr & tampalrm)))
return -EBUSY;
break;
default:
return -EINVAL;
}
if (clk_get_rate(rtc->rtc_ck) != 32768)
return -ERANGE;
return 0;
}
static int stm32_rtc_pinmux_action_lsco(struct pinctrl_dev *pctldev, unsigned int pin)
{
struct stm32_rtc *rtc = pinctrl_dev_get_drvdata(pctldev);
struct stm32_rtc_registers regs = rtc->data->regs;
struct device *dev = rtc->rtc_dev->dev.parent;
u8 lscoen;
int ret;
if (!rtc->data->has_lsco)
return -EPERM;
ret = stm32_rtc_pinmux_lsco_available(pctldev, pin);
if (ret)
return ret;
lscoen = (pin == OUT1) ? STM32_RTC_CFGR_LSCOEN_OUT1 : STM32_RTC_CFGR_LSCOEN_OUT2_RMP;
rtc->clk_lsco = clk_register_gate(dev, "rtc_lsco", __clk_get_name(rtc->rtc_ck),
CLK_IGNORE_UNUSED | CLK_IS_CRITICAL,
rtc->base + regs.cfgr, lscoen, 0, NULL);
if (IS_ERR(rtc->clk_lsco))
return PTR_ERR(rtc->clk_lsco);
of_clk_add_provider(dev->of_node, of_clk_src_simple_get, rtc->clk_lsco);
return 0;
}
static const struct stm32_rtc_pinmux_func stm32_rtc_pinmux_functions[] = {
STM32_RTC_PINMUX("lsco", &stm32_rtc_pinmux_action_lsco, "out1", "out2_rmp"),
STM32_RTC_PINMUX("alarm-a", &stm32_rtc_pinmux_action_alarm, "out1", "out2", "out2_rmp"),
};
static int stm32_rtc_pinmux_get_functions_count(struct pinctrl_dev *pctldev)
{
return ARRAY_SIZE(stm32_rtc_pinmux_functions);
}
static const char *stm32_rtc_pinmux_get_fname(struct pinctrl_dev *pctldev, unsigned int selector)
{
return stm32_rtc_pinmux_functions[selector].name;
}
static int stm32_rtc_pinmux_get_groups(struct pinctrl_dev *pctldev, unsigned int selector,
const char * const **groups, unsigned int * const num_groups)
{
*groups = stm32_rtc_pinmux_functions[selector].groups;
*num_groups = stm32_rtc_pinmux_functions[selector].num_groups;
return 0;
}
static int stm32_rtc_pinmux_set_mux(struct pinctrl_dev *pctldev, unsigned int selector,
unsigned int group)
{
struct stm32_rtc_pinmux_func selected_func = stm32_rtc_pinmux_functions[selector];
struct pinctrl_pin_desc pin = stm32_rtc_pinctrl_pins[group];
/* Call action */
if (selected_func.action)
return selected_func.action(pctldev, pin.number);
return -EINVAL;
}
static const struct pinmux_ops stm32_rtc_pinmux_ops = {
.get_functions_count = stm32_rtc_pinmux_get_functions_count,
.get_function_name = stm32_rtc_pinmux_get_fname,
.get_function_groups = stm32_rtc_pinmux_get_groups,
.set_mux = stm32_rtc_pinmux_set_mux,
.strict = true,
};
static const struct pinctrl_desc stm32_rtc_pdesc = {
.name = DRIVER_NAME,
.pins = stm32_rtc_pinctrl_pins,
.npins = ARRAY_SIZE(stm32_rtc_pinctrl_pins),
.owner = THIS_MODULE,
.pctlops = &stm32_rtc_pinctrl_ops,
.pmxops = &stm32_rtc_pinmux_ops,
};
static int stm32_rtc_enter_init_mode(struct stm32_rtc *rtc)
{
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 + regs->isr);
/*
* It takes around 2 rtc_ck clock cycles to enter in
* initialization phase mode (and have INITF flag set). As
* slowest rtc_ck frequency may be 32kHz and highest should be
* 1MHz, we poll every 10 us with a timeout of 100ms.
*/
return readl_relaxed_poll_timeout_atomic(rtc->base + regs->isr, isr,
(isr & STM32_RTC_ISR_INITF),
10, 100000);
}
return 0;
}
static void stm32_rtc_exit_init_mode(struct stm32_rtc *rtc)
{
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 + regs->isr);
}
static int stm32_rtc_wait_sync(struct stm32_rtc *rtc)
{
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 + 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 + 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;
const struct stm32_rtc_registers *regs = &rtc->data->regs;
const struct stm32_rtc_events *evts = &rtc->data->events;
unsigned int status, cr;
rtc_lock(rtc->rtc_dev);
status = readl_relaxed(rtc->base + regs->sr);
cr = readl_relaxed(rtc->base + regs->cr);
if ((status & evts->alra) &&
(cr & STM32_RTC_CR_ALRAIE)) {
/* Alarm A flag - Alarm interrupt */
dev_dbg(&rtc->rtc_dev->dev, "Alarm occurred\n");
/* Pass event to the kernel */
rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF);
/* Clear event flags, otherwise new events won't be received */
stm32_rtc_clear_event_flags(rtc, evts->alra);
}
rtc_unlock(rtc->rtc_dev);
return IRQ_HANDLED;
}
/* 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);
const struct stm32_rtc_registers *regs = &rtc->data->regs;
unsigned int tr, dr;
/* Time and Date in BCD format */
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;
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);
return 0;
}
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;
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);
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;
}
writel_relaxed(tr, rtc->base + regs->tr);
writel_relaxed(dr, rtc->base + regs->dr);
stm32_rtc_exit_init_mode(rtc);
ret = stm32_rtc_wait_sync(rtc);
end:
stm32_rtc_wpr_lock(rtc);
return ret;
}
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, status;
alrmar = readl_relaxed(rtc->base + regs->alrmar);
cr = readl_relaxed(rtc->base + regs->cr);
status = readl_relaxed(rtc->base + regs->sr);
if (alrmar & STM32_RTC_ALRMXR_DATE_MASK) {
/*
* Date/day doesn't matter 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 matter 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 matter 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 matter 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 = (status & evts->alra) ? 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);
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 + regs->cr);
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);
writel_relaxed(cr, rtc->base + regs->cr);
/* Clear event flags, otherwise new events won't be received */
stm32_rtc_clear_event_flags(rtc, evts->alra);
stm32_rtc_wpr_lock(rtc);
return 0;
}
static int stm32_rtc_valid_alrm(struct device *dev, struct rtc_time *tm)
{
static struct rtc_time now;
time64_t max_alarm_time64;
int max_day_forward;
int next_month;
int next_year;
/*
* Assuming current date is M-D-Y H:M:S.
* RTC alarm can't be set on a specific month and year.
* So the valid alarm range is:
* M-D-Y H:M:S < alarm <= (M+1)-D-Y H:M:S
*/
stm32_rtc_read_time(dev, &now);
/*
* Find the next month and the year of the next month.
* Note: tm_mon and next_month are from 0 to 11
*/
next_month = now.tm_mon + 1;
if (next_month == 12) {
next_month = 0;
next_year = now.tm_year + 1;
} else {
next_year = now.tm_year;
}
/* Find the maximum limit of alarm in days. */
max_day_forward = rtc_month_days(now.tm_mon, now.tm_year)
- now.tm_mday
+ min(rtc_month_days(next_month, next_year), now.tm_mday);
/* Convert to timestamp and compare the alarm time and its upper limit */
max_alarm_time64 = rtc_tm_to_time64(&now) + max_day_forward * SEC_PER_DAY;
return rtc_tm_to_time64(tm) <= max_alarm_time64 ? 0 : -EINVAL;
}
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;
/*
* RTC alarm can't be set on a specific date, unless this date is
* up to the same day of month next month.
*/
if (stm32_rtc_valid_alrm(dev, tm) < 0) {
dev_err(dev, "Alarm can be set only on upcoming month.\n");
return -EINVAL;
}
tm2bcd(tm);
alrmar = 0;
/* tm_year and tm_mon are not used because not supported by RTC */
alrmar |= (tm->tm_mday << STM32_RTC_ALRMXR_DATE_SHIFT) &
STM32_RTC_ALRMXR_DATE;
/* 24-hour format */
alrmar &= ~STM32_RTC_ALRMXR_PM;
alrmar |= (tm->tm_hour << STM32_RTC_ALRMXR_HOUR_SHIFT) &
STM32_RTC_ALRMXR_HOUR;
alrmar |= (tm->tm_min << STM32_RTC_ALRMXR_MIN_SHIFT) &
STM32_RTC_ALRMXR_MIN;
alrmar |= (tm->tm_sec << STM32_RTC_ALRMXR_SEC_SHIFT) &
STM32_RTC_ALRMXR_SEC;
stm32_rtc_wpr_unlock(rtc);
/* Disable Alarm */
cr = readl_relaxed(rtc->base + regs->cr);
cr &= ~STM32_RTC_CR_ALRAE;
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 + regs->isr,
isr,
(isr & STM32_RTC_ISR_ALRAWF),
10, 100000);
if (ret) {
dev_err(dev, "Alarm update not allowed\n");
goto end;
}
/* Write to Alarm register */
writel_relaxed(alrmar, rtc->base + regs->alrmar);
stm32_rtc_alarm_irq_enable(dev, alrm->enabled);
end:
stm32_rtc_wpr_lock(rtc);
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,
};
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,
.need_accuracy = false,
.rif_protected = false,
.has_lsco = false,
.has_alarm_out = false,
.regs = {
.tr = 0x00,
.dr = 0x04,
.cr = 0x08,
.isr = 0x0C,
.prer = 0x10,
.alrmar = 0x1C,
.wpr = 0x24,
.sr = 0x0C, /* set to ISR offset to ease alarm management */
.scr = UNDEF_REG,
.cfgr = UNDEF_REG,
.verr = UNDEF_REG,
},
.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,
.need_accuracy = false,
.rif_protected = false,
.has_lsco = false,
.has_alarm_out = false,
.regs = {
.tr = 0x00,
.dr = 0x04,
.cr = 0x08,
.isr = 0x0C,
.prer = 0x10,
.alrmar = 0x1C,
.wpr = 0x24,
.sr = 0x0C, /* set to ISR offset to ease alarm management */
.scr = UNDEF_REG,
.cfgr = UNDEF_REG,
.verr = UNDEF_REG,
},
.events = {
.alra = STM32_RTC_ISR_ALRAF,
},
.clear_events = stm32_rtc_clear_events,
};
static void stm32mp1_rtc_clear_events(struct stm32_rtc *rtc,
unsigned int flags)
{
struct stm32_rtc_registers regs = rtc->data->regs;
/* Flags are cleared by writing 1 in RTC_SCR */
writel_relaxed(flags, rtc->base + regs.scr);
}
static const struct stm32_rtc_data stm32mp1_data = {
.has_pclk = true,
.need_dbp = false,
.need_accuracy = true,
.rif_protected = false,
.has_lsco = true,
.has_alarm_out = true,
.regs = {
.tr = 0x00,
.dr = 0x04,
.cr = 0x18,
.isr = 0x0C, /* named RTC_ICSR on stm32mp1 */
.prer = 0x10,
.alrmar = 0x40,
.wpr = 0x24,
.sr = 0x50,
.scr = 0x5C,
.cfgr = 0x60,
.verr = 0x3F4,
},
.events = {
.alra = STM32_RTC_SR_ALRA,
},
.clear_events = stm32mp1_rtc_clear_events,
};
static const struct stm32_rtc_data stm32mp25_data = {
.has_pclk = true,
.need_dbp = false,
.need_accuracy = true,
.rif_protected = true,
.has_lsco = true,
.has_alarm_out = true,
.regs = {
.tr = 0x00,
.dr = 0x04,
.cr = 0x18,
.isr = 0x0C, /* named RTC_ICSR on stm32mp25 */
.prer = 0x10,
.alrmar = 0x40,
.wpr = 0x24,
.sr = 0x50,
.scr = 0x5C,
.cfgr = 0x60,
.verr = 0x3F4,
},
.events = {
.alra = STM32_RTC_SR_ALRA,
},
.clear_events = stm32mp1_rtc_clear_events,
};
static const struct of_device_id stm32_rtc_of_match[] = {
{ .compatible = "st,stm32-rtc", .data = &stm32_rtc_data },
{ .compatible = "st,stm32h7-rtc", .data = &stm32h7_rtc_data },
{ .compatible = "st,stm32mp1-rtc", .data = &stm32mp1_data },
{ .compatible = "st,stm32mp25-rtc", .data = &stm32mp25_data },
{}
};
MODULE_DEVICE_TABLE(of, stm32_rtc_of_match);
static void stm32_rtc_clean_outs(struct stm32_rtc *rtc)
{
struct stm32_rtc_registers regs = rtc->data->regs;
unsigned int cr = readl_relaxed(rtc->base + regs.cr);
cr &= ~STM32_RTC_CR_OSEL;
cr &= ~STM32_RTC_CR_TAMPOE;
cr &= ~STM32_RTC_CR_COE;
cr &= ~STM32_RTC_CR_TAMPALRM_TYPE;
cr &= ~STM32_RTC_CR_OUT2EN;
stm32_rtc_wpr_unlock(rtc);
writel_relaxed(cr, rtc->base + regs.cr);
stm32_rtc_wpr_lock(rtc);
if (regs.cfgr != UNDEF_REG) {
unsigned int cfgr = readl_relaxed(rtc->base + regs.cfgr);
cfgr &= ~STM32_RTC_CFGR_LSCOEN;
cfgr &= ~STM32_RTC_CFGR_OUT2_RMP;
writel_relaxed(cfgr, rtc->base + regs.cfgr);
}
}
static int stm32_rtc_check_rif(struct stm32_rtc *stm32_rtc,
struct stm32_rtc_rif_resource res)
{
u32 rxcidcfgr = readl_relaxed(stm32_rtc->base + STM32_RTC_RXCIDCFGR(res.num));
u32 seccfgr;
/* Check if RTC available for our CID */
if ((rxcidcfgr & STM32_RTC_RXCIDCFGR_CFEN) &&
(FIELD_GET(STM32_RTC_RXCIDCFGR_CID, rxcidcfgr) != STM32_RTC_RXCIDCFGR_CID1))
return -EACCES;
/* Check if RTC available for non secure world */
seccfgr = readl_relaxed(stm32_rtc->base + STM32_RTC_SECCFGR);
if ((seccfgr & STM32_RTC_SECCFGR_SEC) | (seccfgr & res.bit))
return -EACCES;
return 0;
}
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;
rate = clk_get_rate(rtc->rtc_ck);
/* 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;
if (rate > (pred_a_max + 1) * (pred_s_max + 1)) {
dev_err(&pdev->dev, "rtc_ck rate is too high: %dHz\n", rate);
return -EINVAL;
}
if (rtc->data->need_accuracy) {
for (pred_a = 0; pred_a <= pred_a_max; pred_a++) {
pred_s = (rate / (pred_a + 1)) - 1;
if (pred_s <= pred_s_max && ((pred_s + 1) * (pred_a + 1)) == rate)
break;
}
} else {
for (pred_a = pred_a_max; pred_a + 1 > 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, "rtc_ck is %s\n",
(rate < ((pred_a + 1) * (pred_s + 1))) ?
"fast" : "slow");
}
cr = readl_relaxed(rtc->base + regs->cr);
prer = readl_relaxed(rtc->base + regs->prer);
prer &= STM32_RTC_PRER_PRED_S | STM32_RTC_PRER_PRED_A;
pred_s = (pred_s << STM32_RTC_PRER_PRED_S_SHIFT) &
STM32_RTC_PRER_PRED_S;
pred_a = (pred_a << STM32_RTC_PRER_PRED_A_SHIFT) &
STM32_RTC_PRER_PRED_A;
/* quit if there is nothing to initialize */
if ((cr & STM32_RTC_CR_FMT) == 0 && prer == (pred_s | pred_a))
return 0;
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;
}
writel_relaxed(pred_s, rtc->base + regs->prer);
writel_relaxed(pred_a | pred_s, rtc->base + regs->prer);
/* Force 24h time format */
cr &= ~STM32_RTC_CR_FMT;
writel_relaxed(cr, rtc->base + regs->cr);
stm32_rtc_exit_init_mode(rtc);
ret = stm32_rtc_wait_sync(rtc);
end:
stm32_rtc_wpr_lock(rtc);
return ret;
}
static int stm32_rtc_probe(struct platform_device *pdev)
{
struct stm32_rtc *rtc;
const struct stm32_rtc_registers *regs;
struct pinctrl_dev *pctl;
int ret;
rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
if (!rtc)
return -ENOMEM;
rtc->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(rtc->base))
return PTR_ERR(rtc->base);
rtc->data = (struct stm32_rtc_data *)
of_device_get_match_data(&pdev->dev);
regs = &rtc->data->regs;
if (rtc->data->need_dbp) {
unsigned int args[2];
rtc->dbp = syscon_regmap_lookup_by_phandle_args(pdev->dev.of_node,
"st,syscfg",
2, args);
if (IS_ERR(rtc->dbp)) {
dev_err(&pdev->dev, "no st,syscfg\n");
return PTR_ERR(rtc->dbp);
}
rtc->dbp_reg = args[0];
rtc->dbp_mask = args[1];
}
if (!rtc->data->has_pclk) {
rtc->pclk = NULL;
rtc->rtc_ck = devm_clk_get(&pdev->dev, NULL);
} else {
rtc->pclk = devm_clk_get(&pdev->dev, "pclk");
if (IS_ERR(rtc->pclk))
return dev_err_probe(&pdev->dev, PTR_ERR(rtc->pclk), "no pclk clock");
rtc->rtc_ck = devm_clk_get(&pdev->dev, "rtc_ck");
}
if (IS_ERR(rtc->rtc_ck))
return dev_err_probe(&pdev->dev, PTR_ERR(rtc->rtc_ck), "no rtc_ck clock");
if (rtc->data->has_pclk) {
ret = clk_prepare_enable(rtc->pclk);
if (ret)
return ret;
}
ret = clk_prepare_enable(rtc->rtc_ck);
if (ret)
goto err_no_rtc_ck;
if (rtc->data->need_dbp)
regmap_update_bits(rtc->dbp, rtc->dbp_reg,
rtc->dbp_mask, rtc->dbp_mask);
if (rtc->data->rif_protected) {
ret = stm32_rtc_check_rif(rtc, STM32_RTC_RES_INIT);
if (!ret)
ret = stm32_rtc_check_rif(rtc, STM32_RTC_RES_ALRA);
if (ret) {
dev_err(&pdev->dev, "Failed to probe RTC due to RIF configuration\n");
goto err;
}
}
/*
* After a system reset, RTC_ISR.INITS flag can be read to check if
* the calendar has been initialized or not. INITS flag is reset by a
* power-on reset (no vbat, no power-supply). It is not reset if
* rtc_ck parent clock has changed (so RTC prescalers need to be
* changed). That's why we cannot rely on this flag to know if RTC
* init has to be done.
*/
ret = stm32_rtc_init(pdev, rtc);
if (ret)
goto err;
rtc->irq_alarm = platform_get_irq(pdev, 0);
if (rtc->irq_alarm <= 0) {
ret = rtc->irq_alarm;
goto err;
}
ret = devm_device_init_wakeup(&pdev->dev);
if (ret)
goto err;
ret = devm_pm_set_wake_irq(&pdev->dev, rtc->irq_alarm);
if (ret)
goto err;
platform_set_drvdata(pdev, rtc);
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_threaded_irq(&pdev->dev, rtc->irq_alarm, NULL,
stm32_rtc_alarm_irq, IRQF_ONESHOT,
pdev->name, rtc);
if (ret) {
dev_err(&pdev->dev, "IRQ%d (alarm interrupt) already claimed\n",
rtc->irq_alarm);
goto err;
}
stm32_rtc_clean_outs(rtc);
ret = devm_pinctrl_register_and_init(&pdev->dev, &stm32_rtc_pdesc, rtc, &pctl);
if (ret)
return dev_err_probe(&pdev->dev, ret, "pinctrl register failed");
ret = pinctrl_enable(pctl);
if (ret)
return dev_err_probe(&pdev->dev, ret, "pinctrl enable failed");
/*
* If INITS flag is reset (calendar year field set to 0x00), calendar
* must be initialized
*/
if (!(readl_relaxed(rtc->base + regs->isr) & STM32_RTC_ISR_INITS))
dev_warn(&pdev->dev, "Date/Time must be initialized\n");
if (regs->verr != UNDEF_REG) {
u32 ver = readl_relaxed(rtc->base + regs->verr);
dev_info(&pdev->dev, "registered rev:%d.%d\n",
(ver >> STM32_RTC_VERR_MAJREV_SHIFT) & 0xF,
(ver >> STM32_RTC_VERR_MINREV_SHIFT) & 0xF);
}
return 0;
err:
clk_disable_unprepare(rtc->rtc_ck);
err_no_rtc_ck:
if (rtc->data->has_pclk)
clk_disable_unprepare(rtc->pclk);
if (rtc->data->need_dbp)
regmap_update_bits(rtc->dbp, rtc->dbp_reg, rtc->dbp_mask, 0);
return ret;
}
static void 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;
if (!IS_ERR_OR_NULL(rtc->clk_lsco))
clk_unregister_gate(rtc->clk_lsco);
/* Disable interrupts */
stm32_rtc_wpr_unlock(rtc);
cr = readl_relaxed(rtc->base + regs->cr);
cr &= ~STM32_RTC_CR_ALRAIE;
writel_relaxed(cr, rtc->base + regs->cr);
stm32_rtc_wpr_lock(rtc);
clk_disable_unprepare(rtc->rtc_ck);
if (rtc->data->has_pclk)
clk_disable_unprepare(rtc->pclk);
/* Enable backup domain write protection if needed */
if (rtc->data->need_dbp)
regmap_update_bits(rtc->dbp, rtc->dbp_reg, rtc->dbp_mask, 0);
}
static int stm32_rtc_suspend(struct device *dev)
{
struct stm32_rtc *rtc = dev_get_drvdata(dev);
if (rtc->data->has_pclk)
clk_disable_unprepare(rtc->pclk);
return 0;
}
static int stm32_rtc_resume(struct device *dev)
{
struct stm32_rtc *rtc = dev_get_drvdata(dev);
int ret = 0;
if (rtc->data->has_pclk) {
ret = clk_prepare_enable(rtc->pclk);
if (ret)
return ret;
}
ret = stm32_rtc_wait_sync(rtc);
if (ret < 0) {
if (rtc->data->has_pclk)
clk_disable_unprepare(rtc->pclk);
return ret;
}
return ret;
}
static const struct dev_pm_ops stm32_rtc_pm_ops = {
NOIRQ_SYSTEM_SLEEP_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_AUTHOR("Amelie Delaunay <amelie.delaunay@st.com>");
MODULE_DESCRIPTION("STMicroelectronics STM32 Real Time Clock driver");
MODULE_LICENSE("GPL v2");
