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