blob: 3e12f57ce0b7ba819f5ce1bb8edd635ee282ba4c [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
/*
* Copyright (C) 2019, STMicroelectronics - All Rights Reserved
*/
#include <common.h>
#include <clk.h>
#include <dm.h>
#include <malloc.h>
#include <rtc.h>
#include <asm/io.h>
#include <dm/device_compat.h>
#include <linux/iopoll.h>
#define STM32_RTC_TR 0x00
#define STM32_RTC_DR 0x04
#define STM32_RTC_ISR 0x0C
#define STM32_RTC_PRER 0x10
#define STM32_RTC_CR 0x18
#define STM32_RTC_WPR 0x24
/* STM32_RTC_TR bit fields */
#define STM32_RTC_SEC_SHIFT 0
#define STM32_RTC_SEC GENMASK(6, 0)
#define STM32_RTC_MIN_SHIFT 8
#define STM32_RTC_MIN GENMASK(14, 8)
#define STM32_RTC_HOUR_SHIFT 16
#define STM32_RTC_HOUR GENMASK(21, 16)
/* STM32_RTC_DR bit fields */
#define STM32_RTC_DATE_SHIFT 0
#define STM32_RTC_DATE GENMASK(5, 0)
#define STM32_RTC_MONTH_SHIFT 8
#define STM32_RTC_MONTH GENMASK(12, 8)
#define STM32_RTC_WDAY_SHIFT 13
#define STM32_RTC_WDAY GENMASK(15, 13)
#define STM32_RTC_YEAR_SHIFT 16
#define STM32_RTC_YEAR GENMASK(23, 16)
/* STM32_RTC_CR bit fields */
#define STM32_RTC_CR_FMT BIT(6)
/* STM32_RTC_ISR/STM32_RTC_ICSR bit fields */
#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)
/* 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_WPR key constants */
#define RTC_WPR_1ST_KEY 0xCA
#define RTC_WPR_2ND_KEY 0x53
#define RTC_WPR_WRONG_KEY 0xFF
struct stm32_rtc_priv {
fdt_addr_t base;
};
static int stm32_rtc_get(struct udevice *dev, struct rtc_time *tm)
{
struct stm32_rtc_priv *priv = dev_get_priv(dev);
u32 tr, dr;
tr = readl(priv->base + STM32_RTC_TR);
dr = readl(priv->base + STM32_RTC_DR);
tm->tm_sec = bcd2bin((tr & STM32_RTC_SEC) >> STM32_RTC_SEC_SHIFT);
tm->tm_min = bcd2bin((tr & STM32_RTC_MIN) >> STM32_RTC_MIN_SHIFT);
tm->tm_hour = bcd2bin((tr & STM32_RTC_HOUR) >> STM32_RTC_HOUR_SHIFT);
tm->tm_mday = bcd2bin((dr & STM32_RTC_DATE) >> STM32_RTC_DATE_SHIFT);
tm->tm_mon = bcd2bin((dr & STM32_RTC_MONTH) >> STM32_RTC_MONTH_SHIFT);
tm->tm_year = 2000 +
bcd2bin((dr & STM32_RTC_YEAR) >> STM32_RTC_YEAR_SHIFT);
tm->tm_wday = bcd2bin((dr & STM32_RTC_WDAY) >> STM32_RTC_WDAY_SHIFT);
tm->tm_yday = 0;
tm->tm_isdst = 0;
dev_dbg(dev, "Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
tm->tm_hour, tm->tm_min, tm->tm_sec);
return 0;
}
static void stm32_rtc_unlock(struct udevice *dev)
{
struct stm32_rtc_priv *priv = dev_get_priv(dev);
writel(RTC_WPR_1ST_KEY, priv->base + STM32_RTC_WPR);
writel(RTC_WPR_2ND_KEY, priv->base + STM32_RTC_WPR);
}
static void stm32_rtc_lock(struct udevice *dev)
{
struct stm32_rtc_priv *priv = dev_get_priv(dev);
writel(RTC_WPR_WRONG_KEY, priv->base + STM32_RTC_WPR);
}
static int stm32_rtc_enter_init_mode(struct udevice *dev)
{
struct stm32_rtc_priv *priv = dev_get_priv(dev);
u32 isr = readl(priv->base + STM32_RTC_ISR);
if (!(isr & STM32_RTC_ISR_INITF)) {
isr |= STM32_RTC_ISR_INIT;
writel(isr, priv->base + STM32_RTC_ISR);
return readl_poll_timeout(priv->base + STM32_RTC_ISR,
isr,
(isr & STM32_RTC_ISR_INITF),
100000);
}
return 0;
}
static int stm32_rtc_wait_sync(struct udevice *dev)
{
struct stm32_rtc_priv *priv = dev_get_priv(dev);
u32 isr = readl(priv->base + STM32_RTC_ISR);
isr &= ~STM32_RTC_ISR_RSF;
writel(isr, priv->base + STM32_RTC_ISR);
/*
* Wait for RSF to be set to ensure the calendar registers are
* synchronised, it takes around 2 rtc_ck clock cycles
*/
return readl_poll_timeout(priv->base + STM32_RTC_ISR,
isr, (isr & STM32_RTC_ISR_RSF),
100000);
}
static void stm32_rtc_exit_init_mode(struct udevice *dev)
{
struct stm32_rtc_priv *priv = dev_get_priv(dev);
u32 isr = readl(priv->base + STM32_RTC_ISR);
isr &= ~STM32_RTC_ISR_INIT;
writel(isr, priv->base + STM32_RTC_ISR);
}
static int stm32_rtc_set_time(struct udevice *dev, u32 time, u32 date)
{
struct stm32_rtc_priv *priv = dev_get_priv(dev);
int ret;
stm32_rtc_unlock(dev);
ret = stm32_rtc_enter_init_mode(dev);
if (ret)
goto lock;
writel(time, priv->base + STM32_RTC_TR);
writel(date, priv->base + STM32_RTC_DR);
stm32_rtc_exit_init_mode(dev);
ret = stm32_rtc_wait_sync(dev);
lock:
stm32_rtc_lock(dev);
return ret;
}
static int stm32_rtc_set(struct udevice *dev, const struct rtc_time *tm)
{
u32 t, d;
dev_dbg(dev, "Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
tm->tm_hour, tm->tm_min, tm->tm_sec);
if (tm->tm_year < 2000 || tm->tm_year > 2099)
return -EINVAL;
/* Time in BCD format */
t = (bin2bcd(tm->tm_sec) << STM32_RTC_SEC_SHIFT) & STM32_RTC_SEC;
t |= (bin2bcd(tm->tm_min) << STM32_RTC_MIN_SHIFT) & STM32_RTC_MIN;
t |= (bin2bcd(tm->tm_hour) << STM32_RTC_HOUR_SHIFT) & STM32_RTC_HOUR;
/* Date in BCD format */
d = (bin2bcd(tm->tm_mday) << STM32_RTC_DATE_SHIFT) & STM32_RTC_DATE;
d |= (bin2bcd(tm->tm_mon) << STM32_RTC_MONTH_SHIFT) & STM32_RTC_MONTH;
d |= (bin2bcd(tm->tm_year - 2000) << STM32_RTC_YEAR_SHIFT) &
STM32_RTC_YEAR;
d |= (bin2bcd(tm->tm_wday) << STM32_RTC_WDAY_SHIFT) & STM32_RTC_WDAY;
return stm32_rtc_set_time(dev, t, d);
}
static int stm32_rtc_reset(struct udevice *dev)
{
dev_dbg(dev, "Reset DATE\n");
return stm32_rtc_set_time(dev, 0, 0);
}
static int stm32_rtc_init(struct udevice *dev)
{
struct stm32_rtc_priv *priv = dev_get_priv(dev);
unsigned int prer, pred_a, pred_s, pred_a_max, pred_s_max, cr;
unsigned int rate;
struct clk clk;
int ret;
u32 isr = readl(priv->base + STM32_RTC_ISR);
if (isr & STM32_RTC_ISR_INITS)
return 0;
ret = clk_get_by_index(dev, 1, &clk);
if (ret)
return ret;
ret = clk_enable(&clk);
if (ret) {
clk_free(&clk);
return ret;
}
rate = clk_get_rate(&clk);
/* 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 + 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;
}
stm32_rtc_unlock(dev);
ret = stm32_rtc_enter_init_mode(dev);
if (ret) {
dev_err(dev,
"Can't enter in init mode. Prescaler config failed.\n");
goto unlock;
}
prer = (pred_s << STM32_RTC_PRER_PRED_S_SHIFT) & STM32_RTC_PRER_PRED_S;
prer |= (pred_a << STM32_RTC_PRER_PRED_A_SHIFT) & STM32_RTC_PRER_PRED_A;
writel(prer, priv->base + STM32_RTC_PRER);
/* Force 24h time format */
cr = readl(priv->base + STM32_RTC_CR);
cr &= ~STM32_RTC_CR_FMT;
writel(cr, priv->base + STM32_RTC_CR);
stm32_rtc_exit_init_mode(dev);
ret = stm32_rtc_wait_sync(dev);
unlock:
stm32_rtc_lock(dev);
if (ret) {
clk_disable(&clk);
clk_free(&clk);
}
return ret;
}
static int stm32_rtc_probe(struct udevice *dev)
{
struct stm32_rtc_priv *priv = dev_get_priv(dev);
struct clk clk;
int ret;
priv->base = dev_read_addr(dev);
if (priv->base == FDT_ADDR_T_NONE)
return -EINVAL;
ret = clk_get_by_index(dev, 0, &clk);
if (ret)
return ret;
ret = clk_enable(&clk);
if (ret) {
clk_free(&clk);
return ret;
}
ret = stm32_rtc_init(dev);
if (ret) {
clk_disable(&clk);
clk_free(&clk);
}
return ret;
}
static const struct rtc_ops stm32_rtc_ops = {
.get = stm32_rtc_get,
.set = stm32_rtc_set,
.reset = stm32_rtc_reset,
};
static const struct udevice_id stm32_rtc_ids[] = {
{ .compatible = "st,stm32mp1-rtc" },
{ }
};
U_BOOT_DRIVER(rtc_stm32) = {
.name = "rtc-stm32",
.id = UCLASS_RTC,
.probe = stm32_rtc_probe,
.of_match = stm32_rtc_ids,
.ops = &stm32_rtc_ops,
.priv_auto_alloc_size = sizeof(struct stm32_rtc_priv),
};