/*
* An RTC driver for Allwinner A31/A23
*
* Copyright (c) 2014, Chen-Yu Tsai <wens@csie.org>
*
* based on rtc-sunxi.c
*
* An RTC driver for Allwinner A10/A20
*
* Copyright (c) 2013, Carlo Caione <carlo.caione@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*/
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/slab.h>
#include <linux/types.h>
/* Control register */
#define SUN6I_LOSC_CTRL 0x0000
#define SUN6I_LOSC_CTRL_KEY (0x16aa << 16)
#define SUN6I_LOSC_CTRL_ALM_DHMS_ACC BIT(9)
#define SUN6I_LOSC_CTRL_RTC_HMS_ACC BIT(8)
#define SUN6I_LOSC_CTRL_RTC_YMD_ACC BIT(7)
#define SUN6I_LOSC_CTRL_EXT_OSC BIT(0)
#define SUN6I_LOSC_CTRL_ACC_MASK GENMASK(9, 7)
#define SUN6I_LOSC_CLK_PRESCAL 0x0008
/* RTC */
#define SUN6I_RTC_YMD 0x0010
#define SUN6I_RTC_HMS 0x0014
/* Alarm 0 (counter) */
#define SUN6I_ALRM_COUNTER 0x0020
#define SUN6I_ALRM_CUR_VAL 0x0024
#define SUN6I_ALRM_EN 0x0028
#define SUN6I_ALRM_EN_CNT_EN BIT(0)
#define SUN6I_ALRM_IRQ_EN 0x002c
#define SUN6I_ALRM_IRQ_EN_CNT_IRQ_EN BIT(0)
#define SUN6I_ALRM_IRQ_STA 0x0030
#define SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND BIT(0)
/* Alarm 1 (wall clock) */
#define SUN6I_ALRM1_EN 0x0044
#define SUN6I_ALRM1_IRQ_EN 0x0048
#define SUN6I_ALRM1_IRQ_STA 0x004c
#define SUN6I_ALRM1_IRQ_STA_WEEK_IRQ_PEND BIT(0)
/* Alarm config */
#define SUN6I_ALARM_CONFIG 0x0050
#define SUN6I_ALARM_CONFIG_WAKEUP BIT(0)
#define SUN6I_LOSC_OUT_GATING 0x0060
#define SUN6I_LOSC_OUT_GATING_EN_OFFSET 0
/*
* Get date values
*/
#define SUN6I_DATE_GET_DAY_VALUE(x) ((x) & 0x0000001f)
#define SUN6I_DATE_GET_MON_VALUE(x) (((x) & 0x00000f00) >> 8)
#define SUN6I_DATE_GET_YEAR_VALUE(x) (((x) & 0x003f0000) >> 16)
#define SUN6I_LEAP_GET_VALUE(x) (((x) & 0x00400000) >> 22)
/*
* Get time values
*/
#define SUN6I_TIME_GET_SEC_VALUE(x) ((x) & 0x0000003f)
#define SUN6I_TIME_GET_MIN_VALUE(x) (((x) & 0x00003f00) >> 8)
#define SUN6I_TIME_GET_HOUR_VALUE(x) (((x) & 0x001f0000) >> 16)
/*
* Set date values
*/
#define SUN6I_DATE_SET_DAY_VALUE(x) ((x) & 0x0000001f)
#define SUN6I_DATE_SET_MON_VALUE(x) ((x) << 8 & 0x00000f00)
#define SUN6I_DATE_SET_YEAR_VALUE(x) ((x) << 16 & 0x003f0000)
#define SUN6I_LEAP_SET_VALUE(x) ((x) << 22 & 0x00400000)
/*
* Set time values
*/
#define SUN6I_TIME_SET_SEC_VALUE(x) ((x) & 0x0000003f)
#define SUN6I_TIME_SET_MIN_VALUE(x) ((x) << 8 & 0x00003f00)
#define SUN6I_TIME_SET_HOUR_VALUE(x) ((x) << 16 & 0x001f0000)
/*
* The year parameter passed to the driver is usually an offset relative to
* the year 1900. This macro is used to convert this offset to another one
* relative to the minimum year allowed by the hardware.
*
* The year range is 1970 - 2033. This range is selected to match Allwinner's
* driver, even though it is somewhat limited.
*/
#define SUN6I_YEAR_MIN 1970
#define SUN6I_YEAR_MAX 2033
#define SUN6I_YEAR_OFF (SUN6I_YEAR_MIN - 1900)
struct sun6i_rtc_dev {
struct rtc_device *rtc;
struct device *dev;
void __iomem *base;
int irq;
unsigned long alarm;
struct clk_hw hw;
struct clk_hw *int_osc;
struct clk *losc;
struct clk *ext_losc;
spinlock_t lock;
};
static struct sun6i_rtc_dev *sun6i_rtc;
static unsigned long sun6i_rtc_osc_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct sun6i_rtc_dev *rtc = container_of(hw, struct sun6i_rtc_dev, hw);
u32 val;
val = readl(rtc->base + SUN6I_LOSC_CTRL);
if (val & SUN6I_LOSC_CTRL_EXT_OSC)
return parent_rate;
val = readl(rtc->base + SUN6I_LOSC_CLK_PRESCAL);
val &= GENMASK(4, 0);
return parent_rate / (val + 1);
}
static u8 sun6i_rtc_osc_get_parent(struct clk_hw *hw)
{
struct sun6i_rtc_dev *rtc = container_of(hw, struct sun6i_rtc_dev, hw);
return readl(rtc->base + SUN6I_LOSC_CTRL) & SUN6I_LOSC_CTRL_EXT_OSC;
}
static int sun6i_rtc_osc_set_parent(struct clk_hw *hw, u8 index)
{
struct sun6i_rtc_dev *rtc = container_of(hw, struct sun6i_rtc_dev, hw);
unsigned long flags;
u32 val;
if (index > 1)
return -EINVAL;
spin_lock_irqsave(&rtc->lock, flags);
val = readl(rtc->base + SUN6I_LOSC_CTRL);
val &= ~SUN6I_LOSC_CTRL_EXT_OSC;
val |= SUN6I_LOSC_CTRL_KEY;
val |= index ? SUN6I_LOSC_CTRL_EXT_OSC : 0;
writel(val, rtc->base + SUN6I_LOSC_CTRL);
spin_unlock_irqrestore(&rtc->lock, flags);
return 0;
}
static const struct clk_ops sun6i_rtc_osc_ops = {
.recalc_rate = sun6i_rtc_osc_recalc_rate,
.get_parent = sun6i_rtc_osc_get_parent,
.set_parent = sun6i_rtc_osc_set_parent,
};
static void __init sun6i_rtc_clk_init(struct device_node *node)
{
struct clk_hw_onecell_data *clk_data;
struct sun6i_rtc_dev *rtc;
struct clk_init_data init = {
.ops = &sun6i_rtc_osc_ops,
};
const char *clkout_name = "osc32k-out";
const char *parents[2];
rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
if (!rtc)
return;
clk_data = kzalloc(struct_size(clk_data, hws, 2), GFP_KERNEL);
if (!clk_data) {
kfree(rtc);
return;
}
spin_lock_init(&rtc->lock);
rtc->base = of_io_request_and_map(node, 0, of_node_full_name(node));
if (IS_ERR(rtc->base)) {
pr_crit("Can't map RTC registers");
goto err;
}
/* Switch to the external, more precise, oscillator */
writel(SUN6I_LOSC_CTRL_KEY | SUN6I_LOSC_CTRL_EXT_OSC,
rtc->base + SUN6I_LOSC_CTRL);
/* Yes, I know, this is ugly. */
sun6i_rtc = rtc;
/* Deal with old DTs */
if (!of_get_property(node, "clocks", NULL))
goto err;
rtc->int_osc = clk_hw_register_fixed_rate_with_accuracy(NULL,
"rtc-int-osc",
NULL, 0,
667000,
300000000);
if (IS_ERR(rtc->int_osc)) {
pr_crit("Couldn't register the internal oscillator\n");
return;
}
parents[0] = clk_hw_get_name(rtc->int_osc);
parents[1] = of_clk_get_parent_name(node, 0);
rtc->hw.init = &init;
init.parent_names = parents;
init.num_parents = of_clk_get_parent_count(node) + 1;
of_property_read_string_index(node, "clock-output-names", 0,
&init.name);
rtc->losc = clk_register(NULL, &rtc->hw);
if (IS_ERR(rtc->losc)) {
pr_crit("Couldn't register the LOSC clock\n");
return;
}
of_property_read_string_index(node, "clock-output-names", 1,
&clkout_name);
rtc->ext_losc = clk_register_gate(NULL, clkout_name, rtc->hw.init->name,
0, rtc->base + SUN6I_LOSC_OUT_GATING,
SUN6I_LOSC_OUT_GATING_EN_OFFSET, 0,
&rtc->lock);
if (IS_ERR(rtc->ext_losc)) {
pr_crit("Couldn't register the LOSC external gate\n");
return;
}
clk_data->num = 2;
clk_data->hws[0] = &rtc->hw;
clk_data->hws[1] = __clk_get_hw(rtc->ext_losc);
of_clk_add_hw_provider(node, of_clk_hw_onecell_get, clk_data);
return;
err:
kfree(clk_data);
}
CLK_OF_DECLARE_DRIVER(sun6i_rtc_clk, "allwinner,sun6i-a31-rtc",
sun6i_rtc_clk_init);
static irqreturn_t sun6i_rtc_alarmirq(int irq, void *id)
{
struct sun6i_rtc_dev *chip = (struct sun6i_rtc_dev *) id;
irqreturn_t ret = IRQ_NONE;
u32 val;
spin_lock(&chip->lock);
val = readl(chip->base + SUN6I_ALRM_IRQ_STA);
if (val & SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND) {
val |= SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND;
writel(val, chip->base + SUN6I_ALRM_IRQ_STA);
rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF);
ret = IRQ_HANDLED;
}
spin_unlock(&chip->lock);
return ret;
}
static void sun6i_rtc_setaie(int to, struct sun6i_rtc_dev *chip)
{
u32 alrm_val = 0;
u32 alrm_irq_val = 0;
u32 alrm_wake_val = 0;
unsigned long flags;
if (to) {
alrm_val = SUN6I_ALRM_EN_CNT_EN;
alrm_irq_val = SUN6I_ALRM_IRQ_EN_CNT_IRQ_EN;
alrm_wake_val = SUN6I_ALARM_CONFIG_WAKEUP;
} else {
writel(SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND,
chip->base + SUN6I_ALRM_IRQ_STA);
}
spin_lock_irqsave(&chip->lock, flags);
writel(alrm_val, chip->base + SUN6I_ALRM_EN);
writel(alrm_irq_val, chip->base + SUN6I_ALRM_IRQ_EN);
writel(alrm_wake_val, chip->base + SUN6I_ALARM_CONFIG);
spin_unlock_irqrestore(&chip->lock, flags);
}
static int sun6i_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
{
struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
u32 date, time;
/*
* read again in case it changes
*/
do {
date = readl(chip->base + SUN6I_RTC_YMD);
time = readl(chip->base + SUN6I_RTC_HMS);
} while ((date != readl(chip->base + SUN6I_RTC_YMD)) ||
(time != readl(chip->base + SUN6I_RTC_HMS)));
rtc_tm->tm_sec = SUN6I_TIME_GET_SEC_VALUE(time);
rtc_tm->tm_min = SUN6I_TIME_GET_MIN_VALUE(time);
rtc_tm->tm_hour = SUN6I_TIME_GET_HOUR_VALUE(time);
rtc_tm->tm_mday = SUN6I_DATE_GET_DAY_VALUE(date);
rtc_tm->tm_mon = SUN6I_DATE_GET_MON_VALUE(date);
rtc_tm->tm_year = SUN6I_DATE_GET_YEAR_VALUE(date);
rtc_tm->tm_mon -= 1;
/*
* switch from (data_year->min)-relative offset to
* a (1900)-relative one
*/
rtc_tm->tm_year += SUN6I_YEAR_OFF;
return 0;
}
static int sun6i_rtc_getalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
{
struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
unsigned long flags;
u32 alrm_st;
u32 alrm_en;
spin_lock_irqsave(&chip->lock, flags);
alrm_en = readl(chip->base + SUN6I_ALRM_IRQ_EN);
alrm_st = readl(chip->base + SUN6I_ALRM_IRQ_STA);
spin_unlock_irqrestore(&chip->lock, flags);
wkalrm->enabled = !!(alrm_en & SUN6I_ALRM_EN_CNT_EN);
wkalrm->pending = !!(alrm_st & SUN6I_ALRM_EN_CNT_EN);
rtc_time_to_tm(chip->alarm, &wkalrm->time);
return 0;
}
static int sun6i_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
{
struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
struct rtc_time *alrm_tm = &wkalrm->time;
struct rtc_time tm_now;
unsigned long time_now = 0;
unsigned long time_set = 0;
unsigned long time_gap = 0;
int ret = 0;
ret = sun6i_rtc_gettime(dev, &tm_now);
if (ret < 0) {
dev_err(dev, "Error in getting time\n");
return -EINVAL;
}
rtc_tm_to_time(alrm_tm, &time_set);
rtc_tm_to_time(&tm_now, &time_now);
if (time_set <= time_now) {
dev_err(dev, "Date to set in the past\n");
return -EINVAL;
}
time_gap = time_set - time_now;
if (time_gap > U32_MAX) {
dev_err(dev, "Date too far in the future\n");
return -EINVAL;
}
sun6i_rtc_setaie(0, chip);
writel(0, chip->base + SUN6I_ALRM_COUNTER);
usleep_range(100, 300);
writel(time_gap, chip->base + SUN6I_ALRM_COUNTER);
chip->alarm = time_set;
sun6i_rtc_setaie(wkalrm->enabled, chip);
return 0;
}
static int sun6i_rtc_wait(struct sun6i_rtc_dev *chip, int offset,
unsigned int mask, unsigned int ms_timeout)
{
const unsigned long timeout = jiffies + msecs_to_jiffies(ms_timeout);
u32 reg;
do {
reg = readl(chip->base + offset);
reg &= mask;
if (!reg)
return 0;
} while (time_before(jiffies, timeout));
return -ETIMEDOUT;
}
static int sun6i_rtc_settime(struct device *dev, struct rtc_time *rtc_tm)
{
struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
u32 date = 0;
u32 time = 0;
int year;
year = rtc_tm->tm_year + 1900;
if (year < SUN6I_YEAR_MIN || year > SUN6I_YEAR_MAX) {
dev_err(dev, "rtc only supports year in range %d - %d\n",
SUN6I_YEAR_MIN, SUN6I_YEAR_MAX);
return -EINVAL;
}
rtc_tm->tm_year -= SUN6I_YEAR_OFF;
rtc_tm->tm_mon += 1;
date = SUN6I_DATE_SET_DAY_VALUE(rtc_tm->tm_mday) |
SUN6I_DATE_SET_MON_VALUE(rtc_tm->tm_mon) |
SUN6I_DATE_SET_YEAR_VALUE(rtc_tm->tm_year);
if (is_leap_year(year))
date |= SUN6I_LEAP_SET_VALUE(1);
time = SUN6I_TIME_SET_SEC_VALUE(rtc_tm->tm_sec) |
SUN6I_TIME_SET_MIN_VALUE(rtc_tm->tm_min) |
SUN6I_TIME_SET_HOUR_VALUE(rtc_tm->tm_hour);
/* Check whether registers are writable */
if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
SUN6I_LOSC_CTRL_ACC_MASK, 50)) {
dev_err(dev, "rtc is still busy.\n");
return -EBUSY;
}
writel(time, chip->base + SUN6I_RTC_HMS);
/*
* After writing the RTC HH-MM-SS register, the
* SUN6I_LOSC_CTRL_RTC_HMS_ACC bit is set and it will not
* be cleared until the real writing operation is finished
*/
if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
SUN6I_LOSC_CTRL_RTC_HMS_ACC, 50)) {
dev_err(dev, "Failed to set rtc time.\n");
return -ETIMEDOUT;
}
writel(date, chip->base + SUN6I_RTC_YMD);
/*
* After writing the RTC YY-MM-DD register, the
* SUN6I_LOSC_CTRL_RTC_YMD_ACC bit is set and it will not
* be cleared until the real writing operation is finished
*/
if (sun6i_rtc_wait(chip, SUN6I_LOSC_CTRL,
SUN6I_LOSC_CTRL_RTC_YMD_ACC, 50)) {
dev_err(dev, "Failed to set rtc time.\n");
return -ETIMEDOUT;
}
return 0;
}
static int sun6i_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct sun6i_rtc_dev *chip = dev_get_drvdata(dev);
if (!enabled)
sun6i_rtc_setaie(enabled, chip);
return 0;
}
static const struct rtc_class_ops sun6i_rtc_ops = {
.read_time = sun6i_rtc_gettime,
.set_time = sun6i_rtc_settime,
.read_alarm = sun6i_rtc_getalarm,
.set_alarm = sun6i_rtc_setalarm,
.alarm_irq_enable = sun6i_rtc_alarm_irq_enable
};
static int sun6i_rtc_probe(struct platform_device *pdev)
{
struct sun6i_rtc_dev *chip = sun6i_rtc;
int ret;
if (!chip)
return -ENODEV;
platform_set_drvdata(pdev, chip);
chip->dev = &pdev->dev;
chip->irq = platform_get_irq(pdev, 0);
if (chip->irq < 0) {
dev_err(&pdev->dev, "No IRQ resource\n");
return chip->irq;
}
ret = devm_request_irq(&pdev->dev, chip->irq, sun6i_rtc_alarmirq,
0, dev_name(&pdev->dev), chip);
if (ret) {
dev_err(&pdev->dev, "Could not request IRQ\n");
return ret;
}
/* clear the alarm counter value */
writel(0, chip->base + SUN6I_ALRM_COUNTER);
/* disable counter alarm */
writel(0, chip->base + SUN6I_ALRM_EN);
/* disable counter alarm interrupt */
writel(0, chip->base + SUN6I_ALRM_IRQ_EN);
/* disable week alarm */
writel(0, chip->base + SUN6I_ALRM1_EN);
/* disable week alarm interrupt */
writel(0, chip->base + SUN6I_ALRM1_IRQ_EN);
/* clear counter alarm pending interrupts */
writel(SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND,
chip->base + SUN6I_ALRM_IRQ_STA);
/* clear week alarm pending interrupts */
writel(SUN6I_ALRM1_IRQ_STA_WEEK_IRQ_PEND,
chip->base + SUN6I_ALRM1_IRQ_STA);
/* disable alarm wakeup */
writel(0, chip->base + SUN6I_ALARM_CONFIG);
clk_prepare_enable(chip->losc);
chip->rtc = devm_rtc_device_register(&pdev->dev, "rtc-sun6i",
&sun6i_rtc_ops, THIS_MODULE);
if (IS_ERR(chip->rtc)) {
dev_err(&pdev->dev, "unable to register device\n");
return PTR_ERR(chip->rtc);
}
dev_info(&pdev->dev, "RTC enabled\n");
return 0;
}
static const struct of_device_id sun6i_rtc_dt_ids[] = {
{ .compatible = "allwinner,sun6i-a31-rtc" },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, sun6i_rtc_dt_ids);
static struct platform_driver sun6i_rtc_driver = {
.probe = sun6i_rtc_probe,
.driver = {
.name = "sun6i-rtc",
.of_match_table = sun6i_rtc_dt_ids,
},
};
builtin_platform_driver(sun6i_rtc_driver);
