linux-stable/drivers/rtc/rtc-mt7622.c
Thomas Gleixner c942fddf87 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157
Based on 3 normalized pattern(s):

  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

  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 [author] [kishon] [vijay] [abraham]
  [i] [kishon]@[ti] [com] 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

  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 [author] [graeme] [gregory]
  [gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i]
  [kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema]
  [hk] [hemahk]@[ti] [com] 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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1105 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:37 -07:00

414 lines
9.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Driver for MediaTek SoC based RTC
*
* Copyright (C) 2017 Sean Wang <sean.wang@mediatek.com>
*/
#include <linux/clk.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#define MTK_RTC_DEV KBUILD_MODNAME
#define MTK_RTC_PWRCHK1 0x4
#define RTC_PWRCHK1_MAGIC 0xc6
#define MTK_RTC_PWRCHK2 0x8
#define RTC_PWRCHK2_MAGIC 0x9a
#define MTK_RTC_KEY 0xc
#define RTC_KEY_MAGIC 0x59
#define MTK_RTC_PROT1 0x10
#define RTC_PROT1_MAGIC 0xa3
#define MTK_RTC_PROT2 0x14
#define RTC_PROT2_MAGIC 0x57
#define MTK_RTC_PROT3 0x18
#define RTC_PROT3_MAGIC 0x67
#define MTK_RTC_PROT4 0x1c
#define RTC_PROT4_MAGIC 0xd2
#define MTK_RTC_CTL 0x20
#define RTC_RC_STOP BIT(0)
#define MTK_RTC_DEBNCE 0x2c
#define RTC_DEBNCE_MASK GENMASK(2, 0)
#define MTK_RTC_INT 0x30
#define RTC_INT_AL_STA BIT(4)
/*
* Ranges from 0x40 to 0x78 provide RTC time setup for year, month,
* day of month, day of week, hour, minute and second.
*/
#define MTK_RTC_TREG(_t, _f) (0x40 + (0x4 * (_f)) + ((_t) * 0x20))
#define MTK_RTC_AL_CTL 0x7c
#define RTC_AL_EN BIT(0)
#define RTC_AL_ALL GENMASK(7, 0)
/*
* The offset is used in the translation for the year between in struct
* rtc_time and in hardware register MTK_RTC_TREG(x,MTK_YEA)
*/
#define MTK_RTC_TM_YR_OFFSET 100
/*
* The lowest value for the valid tm_year. RTC hardware would take incorrectly
* tm_year 100 as not a leap year and thus it is also required being excluded
* from the valid options.
*/
#define MTK_RTC_TM_YR_L (MTK_RTC_TM_YR_OFFSET + 1)
/*
* The most year the RTC can hold is 99 and the next to 99 in year register
* would be wraparound to 0, for MT7622.
*/
#define MTK_RTC_HW_YR_LIMIT 99
/* The highest value for the valid tm_year */
#define MTK_RTC_TM_YR_H (MTK_RTC_TM_YR_OFFSET + MTK_RTC_HW_YR_LIMIT)
/* Simple macro helps to check whether the hardware supports the tm_year */
#define MTK_RTC_TM_YR_VALID(_y) ((_y) >= MTK_RTC_TM_YR_L && \
(_y) <= MTK_RTC_TM_YR_H)
/* Types of the function the RTC provides are time counter and alarm. */
enum {
MTK_TC,
MTK_AL,
};
/* Indexes are used for the pointer to relevant registers in MTK_RTC_TREG */
enum {
MTK_YEA,
MTK_MON,
MTK_DOM,
MTK_DOW,
MTK_HOU,
MTK_MIN,
MTK_SEC
};
struct mtk_rtc {
struct rtc_device *rtc;
void __iomem *base;
int irq;
struct clk *clk;
};
static void mtk_w32(struct mtk_rtc *rtc, u32 reg, u32 val)
{
writel_relaxed(val, rtc->base + reg);
}
static u32 mtk_r32(struct mtk_rtc *rtc, u32 reg)
{
return readl_relaxed(rtc->base + reg);
}
static void mtk_rmw(struct mtk_rtc *rtc, u32 reg, u32 mask, u32 set)
{
u32 val;
val = mtk_r32(rtc, reg);
val &= ~mask;
val |= set;
mtk_w32(rtc, reg, val);
}
static void mtk_set(struct mtk_rtc *rtc, u32 reg, u32 val)
{
mtk_rmw(rtc, reg, 0, val);
}
static void mtk_clr(struct mtk_rtc *rtc, u32 reg, u32 val)
{
mtk_rmw(rtc, reg, val, 0);
}
static void mtk_rtc_hw_init(struct mtk_rtc *hw)
{
/* The setup of the init sequence is for allowing RTC got to work */
mtk_w32(hw, MTK_RTC_PWRCHK1, RTC_PWRCHK1_MAGIC);
mtk_w32(hw, MTK_RTC_PWRCHK2, RTC_PWRCHK2_MAGIC);
mtk_w32(hw, MTK_RTC_KEY, RTC_KEY_MAGIC);
mtk_w32(hw, MTK_RTC_PROT1, RTC_PROT1_MAGIC);
mtk_w32(hw, MTK_RTC_PROT2, RTC_PROT2_MAGIC);
mtk_w32(hw, MTK_RTC_PROT3, RTC_PROT3_MAGIC);
mtk_w32(hw, MTK_RTC_PROT4, RTC_PROT4_MAGIC);
mtk_rmw(hw, MTK_RTC_DEBNCE, RTC_DEBNCE_MASK, 0);
mtk_clr(hw, MTK_RTC_CTL, RTC_RC_STOP);
}
static void mtk_rtc_get_alarm_or_time(struct mtk_rtc *hw, struct rtc_time *tm,
int time_alarm)
{
u32 year, mon, mday, wday, hour, min, sec;
/*
* Read again until the field of the second is not changed which
* ensures all fields in the consistent state. Note that MTK_SEC must
* be read first. In this way, it guarantees the others remain not
* changed when the results for two MTK_SEC consecutive reads are same.
*/
do {
sec = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_SEC));
min = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_MIN));
hour = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_HOU));
wday = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_DOW));
mday = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_DOM));
mon = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_MON));
year = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_YEA));
} while (sec != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_SEC)));
tm->tm_sec = sec;
tm->tm_min = min;
tm->tm_hour = hour;
tm->tm_wday = wday;
tm->tm_mday = mday;
tm->tm_mon = mon - 1;
/* Rebase to the absolute year which userspace queries */
tm->tm_year = year + MTK_RTC_TM_YR_OFFSET;
}
static void mtk_rtc_set_alarm_or_time(struct mtk_rtc *hw, struct rtc_time *tm,
int time_alarm)
{
u32 year;
/* Rebase to the relative year which RTC hardware requires */
year = tm->tm_year - MTK_RTC_TM_YR_OFFSET;
mtk_w32(hw, MTK_RTC_TREG(time_alarm, MTK_YEA), year);
mtk_w32(hw, MTK_RTC_TREG(time_alarm, MTK_MON), tm->tm_mon + 1);
mtk_w32(hw, MTK_RTC_TREG(time_alarm, MTK_DOW), tm->tm_wday);
mtk_w32(hw, MTK_RTC_TREG(time_alarm, MTK_DOM), tm->tm_mday);
mtk_w32(hw, MTK_RTC_TREG(time_alarm, MTK_HOU), tm->tm_hour);
mtk_w32(hw, MTK_RTC_TREG(time_alarm, MTK_MIN), tm->tm_min);
mtk_w32(hw, MTK_RTC_TREG(time_alarm, MTK_SEC), tm->tm_sec);
}
static irqreturn_t mtk_rtc_alarmirq(int irq, void *id)
{
struct mtk_rtc *hw = (struct mtk_rtc *)id;
u32 irq_sta;
irq_sta = mtk_r32(hw, MTK_RTC_INT);
if (irq_sta & RTC_INT_AL_STA) {
/* Stop alarm also implicitly disables the alarm interrupt */
mtk_w32(hw, MTK_RTC_AL_CTL, 0);
rtc_update_irq(hw->rtc, 1, RTC_IRQF | RTC_AF);
/* Ack alarm interrupt status */
mtk_w32(hw, MTK_RTC_INT, RTC_INT_AL_STA);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
static int mtk_rtc_gettime(struct device *dev, struct rtc_time *tm)
{
struct mtk_rtc *hw = dev_get_drvdata(dev);
mtk_rtc_get_alarm_or_time(hw, tm, MTK_TC);
return 0;
}
static int mtk_rtc_settime(struct device *dev, struct rtc_time *tm)
{
struct mtk_rtc *hw = dev_get_drvdata(dev);
if (!MTK_RTC_TM_YR_VALID(tm->tm_year))
return -EINVAL;
/* Stop time counter before setting a new one*/
mtk_set(hw, MTK_RTC_CTL, RTC_RC_STOP);
mtk_rtc_set_alarm_or_time(hw, tm, MTK_TC);
/* Restart the time counter */
mtk_clr(hw, MTK_RTC_CTL, RTC_RC_STOP);
return 0;
}
static int mtk_rtc_getalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
{
struct mtk_rtc *hw = dev_get_drvdata(dev);
struct rtc_time *alrm_tm = &wkalrm->time;
mtk_rtc_get_alarm_or_time(hw, alrm_tm, MTK_AL);
wkalrm->enabled = !!(mtk_r32(hw, MTK_RTC_AL_CTL) & RTC_AL_EN);
wkalrm->pending = !!(mtk_r32(hw, MTK_RTC_INT) & RTC_INT_AL_STA);
return 0;
}
static int mtk_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
{
struct mtk_rtc *hw = dev_get_drvdata(dev);
struct rtc_time *alrm_tm = &wkalrm->time;
if (!MTK_RTC_TM_YR_VALID(alrm_tm->tm_year))
return -EINVAL;
/*
* Stop the alarm also implicitly including disables interrupt before
* setting a new one.
*/
mtk_clr(hw, MTK_RTC_AL_CTL, RTC_AL_EN);
/*
* Avoid contention between mtk_rtc_setalarm and IRQ handler so that
* disabling the interrupt and awaiting for pending IRQ handler to
* complete.
*/
synchronize_irq(hw->irq);
mtk_rtc_set_alarm_or_time(hw, alrm_tm, MTK_AL);
/* Restart the alarm with the new setup */
mtk_w32(hw, MTK_RTC_AL_CTL, RTC_AL_ALL);
return 0;
}
static const struct rtc_class_ops mtk_rtc_ops = {
.read_time = mtk_rtc_gettime,
.set_time = mtk_rtc_settime,
.read_alarm = mtk_rtc_getalarm,
.set_alarm = mtk_rtc_setalarm,
};
static const struct of_device_id mtk_rtc_match[] = {
{ .compatible = "mediatek,mt7622-rtc" },
{ .compatible = "mediatek,soc-rtc" },
{},
};
MODULE_DEVICE_TABLE(of, mtk_rtc_match);
static int mtk_rtc_probe(struct platform_device *pdev)
{
struct mtk_rtc *hw;
struct resource *res;
int ret;
hw = devm_kzalloc(&pdev->dev, sizeof(*hw), GFP_KERNEL);
if (!hw)
return -ENOMEM;
platform_set_drvdata(pdev, hw);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
hw->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(hw->base))
return PTR_ERR(hw->base);
hw->clk = devm_clk_get(&pdev->dev, "rtc");
if (IS_ERR(hw->clk)) {
dev_err(&pdev->dev, "No clock\n");
return PTR_ERR(hw->clk);
}
ret = clk_prepare_enable(hw->clk);
if (ret)
return ret;
hw->irq = platform_get_irq(pdev, 0);
if (hw->irq < 0) {
dev_err(&pdev->dev, "No IRQ resource\n");
ret = hw->irq;
goto err;
}
ret = devm_request_irq(&pdev->dev, hw->irq, mtk_rtc_alarmirq,
0, dev_name(&pdev->dev), hw);
if (ret) {
dev_err(&pdev->dev, "Can't request IRQ\n");
goto err;
}
mtk_rtc_hw_init(hw);
device_init_wakeup(&pdev->dev, true);
hw->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
&mtk_rtc_ops, THIS_MODULE);
if (IS_ERR(hw->rtc)) {
ret = PTR_ERR(hw->rtc);
dev_err(&pdev->dev, "Unable to register device\n");
goto err;
}
return 0;
err:
clk_disable_unprepare(hw->clk);
return ret;
}
static int mtk_rtc_remove(struct platform_device *pdev)
{
struct mtk_rtc *hw = platform_get_drvdata(pdev);
clk_disable_unprepare(hw->clk);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int mtk_rtc_suspend(struct device *dev)
{
struct mtk_rtc *hw = dev_get_drvdata(dev);
if (device_may_wakeup(dev))
enable_irq_wake(hw->irq);
return 0;
}
static int mtk_rtc_resume(struct device *dev)
{
struct mtk_rtc *hw = dev_get_drvdata(dev);
if (device_may_wakeup(dev))
disable_irq_wake(hw->irq);
return 0;
}
static SIMPLE_DEV_PM_OPS(mtk_rtc_pm_ops, mtk_rtc_suspend, mtk_rtc_resume);
#define MTK_RTC_PM_OPS (&mtk_rtc_pm_ops)
#else /* CONFIG_PM */
#define MTK_RTC_PM_OPS NULL
#endif /* CONFIG_PM */
static struct platform_driver mtk_rtc_driver = {
.probe = mtk_rtc_probe,
.remove = mtk_rtc_remove,
.driver = {
.name = MTK_RTC_DEV,
.of_match_table = mtk_rtc_match,
.pm = MTK_RTC_PM_OPS,
},
};
module_platform_driver(mtk_rtc_driver);
MODULE_DESCRIPTION("MediaTek SoC based RTC Driver");
MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
MODULE_LICENSE("GPL");