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326 lines
8.1 KiB
326 lines
8.1 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Motorola CPCAP PMIC RTC driver |
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* |
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* Based on cpcap-regulator.c from Motorola Linux kernel tree |
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* Copyright (C) 2009 Motorola, Inc. |
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* |
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* Rewritten for mainline kernel |
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* - use DT |
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* - use regmap |
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* - use standard interrupt framework |
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* - use managed device resources |
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* - remove custom "secure clock daemon" helpers |
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* |
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* Copyright (C) 2017 Sebastian Reichel <[email protected]> |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/mod_devicetable.h> |
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#include <linux/init.h> |
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#include <linux/device.h> |
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#include <linux/platform_device.h> |
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#include <linux/rtc.h> |
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#include <linux/err.h> |
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#include <linux/regmap.h> |
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#include <linux/mfd/motorola-cpcap.h> |
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#include <linux/slab.h> |
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#include <linux/sched.h> |
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#define SECS_PER_DAY 86400 |
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#define DAY_MASK 0x7FFF |
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#define TOD1_MASK 0x00FF |
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#define TOD2_MASK 0x01FF |
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struct cpcap_time { |
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int day; |
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int tod1; |
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int tod2; |
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}; |
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struct cpcap_rtc { |
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struct regmap *regmap; |
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struct rtc_device *rtc_dev; |
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u16 vendor; |
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int alarm_irq; |
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bool alarm_enabled; |
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int update_irq; |
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bool update_enabled; |
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}; |
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static void cpcap2rtc_time(struct rtc_time *rtc, struct cpcap_time *cpcap) |
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{ |
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unsigned long int tod; |
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unsigned long int time; |
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tod = (cpcap->tod1 & TOD1_MASK) | ((cpcap->tod2 & TOD2_MASK) << 8); |
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time = tod + ((cpcap->day & DAY_MASK) * SECS_PER_DAY); |
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rtc_time64_to_tm(time, rtc); |
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} |
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static void rtc2cpcap_time(struct cpcap_time *cpcap, struct rtc_time *rtc) |
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{ |
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unsigned long time; |
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time = rtc_tm_to_time64(rtc); |
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cpcap->day = time / SECS_PER_DAY; |
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time %= SECS_PER_DAY; |
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cpcap->tod2 = (time >> 8) & TOD2_MASK; |
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cpcap->tod1 = time & TOD1_MASK; |
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} |
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static int cpcap_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) |
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{ |
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struct cpcap_rtc *rtc = dev_get_drvdata(dev); |
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if (rtc->alarm_enabled == enabled) |
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return 0; |
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if (enabled) |
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enable_irq(rtc->alarm_irq); |
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else |
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disable_irq(rtc->alarm_irq); |
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rtc->alarm_enabled = !!enabled; |
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return 0; |
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} |
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static int cpcap_rtc_read_time(struct device *dev, struct rtc_time *tm) |
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{ |
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struct cpcap_rtc *rtc; |
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struct cpcap_time cpcap_tm; |
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int temp_tod2; |
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int ret; |
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rtc = dev_get_drvdata(dev); |
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ret = regmap_read(rtc->regmap, CPCAP_REG_TOD2, &temp_tod2); |
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ret |= regmap_read(rtc->regmap, CPCAP_REG_DAY, &cpcap_tm.day); |
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ret |= regmap_read(rtc->regmap, CPCAP_REG_TOD1, &cpcap_tm.tod1); |
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ret |= regmap_read(rtc->regmap, CPCAP_REG_TOD2, &cpcap_tm.tod2); |
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if (temp_tod2 > cpcap_tm.tod2) |
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ret |= regmap_read(rtc->regmap, CPCAP_REG_DAY, &cpcap_tm.day); |
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if (ret) { |
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dev_err(dev, "Failed to read time\n"); |
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return -EIO; |
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} |
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cpcap2rtc_time(tm, &cpcap_tm); |
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return 0; |
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} |
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static int cpcap_rtc_set_time(struct device *dev, struct rtc_time *tm) |
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{ |
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struct cpcap_rtc *rtc; |
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struct cpcap_time cpcap_tm; |
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int ret = 0; |
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rtc = dev_get_drvdata(dev); |
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rtc2cpcap_time(&cpcap_tm, tm); |
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if (rtc->alarm_enabled) |
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disable_irq(rtc->alarm_irq); |
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if (rtc->update_enabled) |
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disable_irq(rtc->update_irq); |
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if (rtc->vendor == CPCAP_VENDOR_ST) { |
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/* The TOD1 and TOD2 registers MUST be written in this order |
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* for the change to properly set. |
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*/ |
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ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_TOD1, |
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TOD1_MASK, cpcap_tm.tod1); |
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ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_TOD2, |
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TOD2_MASK, cpcap_tm.tod2); |
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ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_DAY, |
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DAY_MASK, cpcap_tm.day); |
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} else { |
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/* Clearing the upper lower 8 bits of the TOD guarantees that |
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* the upper half of TOD (TOD2) will not increment for 0xFF RTC |
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* ticks (255 seconds). During this time we can safely write |
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* to DAY, TOD2, then TOD1 (in that order) and expect RTC to be |
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* synchronized to the exact time requested upon the final write |
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* to TOD1. |
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*/ |
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ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_TOD1, |
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TOD1_MASK, 0); |
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ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_DAY, |
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DAY_MASK, cpcap_tm.day); |
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ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_TOD2, |
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TOD2_MASK, cpcap_tm.tod2); |
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ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_TOD1, |
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TOD1_MASK, cpcap_tm.tod1); |
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} |
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if (rtc->update_enabled) |
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enable_irq(rtc->update_irq); |
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if (rtc->alarm_enabled) |
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enable_irq(rtc->alarm_irq); |
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return ret; |
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} |
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static int cpcap_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) |
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{ |
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struct cpcap_rtc *rtc; |
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struct cpcap_time cpcap_tm; |
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int ret; |
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rtc = dev_get_drvdata(dev); |
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alrm->enabled = rtc->alarm_enabled; |
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ret = regmap_read(rtc->regmap, CPCAP_REG_DAYA, &cpcap_tm.day); |
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ret |= regmap_read(rtc->regmap, CPCAP_REG_TODA2, &cpcap_tm.tod2); |
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ret |= regmap_read(rtc->regmap, CPCAP_REG_TODA1, &cpcap_tm.tod1); |
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if (ret) { |
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dev_err(dev, "Failed to read time\n"); |
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return -EIO; |
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} |
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cpcap2rtc_time(&alrm->time, &cpcap_tm); |
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return rtc_valid_tm(&alrm->time); |
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} |
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static int cpcap_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) |
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{ |
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struct cpcap_rtc *rtc; |
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struct cpcap_time cpcap_tm; |
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int ret; |
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rtc = dev_get_drvdata(dev); |
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rtc2cpcap_time(&cpcap_tm, &alrm->time); |
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if (rtc->alarm_enabled) |
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disable_irq(rtc->alarm_irq); |
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ret = regmap_update_bits(rtc->regmap, CPCAP_REG_DAYA, DAY_MASK, |
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cpcap_tm.day); |
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ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_TODA2, TOD2_MASK, |
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cpcap_tm.tod2); |
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ret |= regmap_update_bits(rtc->regmap, CPCAP_REG_TODA1, TOD1_MASK, |
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cpcap_tm.tod1); |
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if (!ret) { |
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enable_irq(rtc->alarm_irq); |
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rtc->alarm_enabled = true; |
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} |
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return ret; |
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} |
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static const struct rtc_class_ops cpcap_rtc_ops = { |
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.read_time = cpcap_rtc_read_time, |
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.set_time = cpcap_rtc_set_time, |
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.read_alarm = cpcap_rtc_read_alarm, |
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.set_alarm = cpcap_rtc_set_alarm, |
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.alarm_irq_enable = cpcap_rtc_alarm_irq_enable, |
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}; |
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static irqreturn_t cpcap_rtc_alarm_irq(int irq, void *data) |
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{ |
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struct cpcap_rtc *rtc = data; |
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rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF); |
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return IRQ_HANDLED; |
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} |
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static irqreturn_t cpcap_rtc_update_irq(int irq, void *data) |
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{ |
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struct cpcap_rtc *rtc = data; |
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rtc_update_irq(rtc->rtc_dev, 1, RTC_UF | RTC_IRQF); |
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return IRQ_HANDLED; |
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} |
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static int cpcap_rtc_probe(struct platform_device *pdev) |
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{ |
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struct device *dev = &pdev->dev; |
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struct cpcap_rtc *rtc; |
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int err; |
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rtc = devm_kzalloc(dev, sizeof(*rtc), GFP_KERNEL); |
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if (!rtc) |
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return -ENOMEM; |
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rtc->regmap = dev_get_regmap(dev->parent, NULL); |
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if (!rtc->regmap) |
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return -ENODEV; |
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platform_set_drvdata(pdev, rtc); |
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rtc->rtc_dev = devm_rtc_allocate_device(dev); |
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if (IS_ERR(rtc->rtc_dev)) |
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return PTR_ERR(rtc->rtc_dev); |
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rtc->rtc_dev->ops = &cpcap_rtc_ops; |
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rtc->rtc_dev->range_max = (timeu64_t) (DAY_MASK + 1) * SECS_PER_DAY - 1; |
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err = cpcap_get_vendor(dev, rtc->regmap, &rtc->vendor); |
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if (err) |
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return err; |
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rtc->alarm_irq = platform_get_irq(pdev, 0); |
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err = devm_request_threaded_irq(dev, rtc->alarm_irq, NULL, |
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cpcap_rtc_alarm_irq, |
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IRQF_TRIGGER_NONE | IRQF_ONESHOT, |
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"rtc_alarm", rtc); |
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if (err) { |
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dev_err(dev, "Could not request alarm irq: %d\n", err); |
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return err; |
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} |
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disable_irq(rtc->alarm_irq); |
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/* Stock Android uses the 1 Hz interrupt for "secure clock daemon", |
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* which is not supported by the mainline kernel. The mainline kernel |
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* does not use the irq at the moment, but we explicitly request and |
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* disable it, so that its masked and does not wake up the processor |
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* every second. |
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*/ |
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rtc->update_irq = platform_get_irq(pdev, 1); |
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err = devm_request_threaded_irq(dev, rtc->update_irq, NULL, |
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cpcap_rtc_update_irq, |
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IRQF_TRIGGER_NONE | IRQF_ONESHOT, |
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"rtc_1hz", rtc); |
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if (err) { |
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dev_err(dev, "Could not request update irq: %d\n", err); |
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return err; |
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} |
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disable_irq(rtc->update_irq); |
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err = device_init_wakeup(dev, 1); |
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if (err) { |
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dev_err(dev, "wakeup initialization failed (%d)\n", err); |
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/* ignore error and continue without wakeup support */ |
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} |
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return devm_rtc_register_device(rtc->rtc_dev); |
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} |
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static const struct of_device_id cpcap_rtc_of_match[] = { |
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{ .compatible = "motorola,cpcap-rtc", }, |
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{}, |
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}; |
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MODULE_DEVICE_TABLE(of, cpcap_rtc_of_match); |
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static struct platform_driver cpcap_rtc_driver = { |
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.probe = cpcap_rtc_probe, |
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.driver = { |
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.name = "cpcap-rtc", |
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.of_match_table = cpcap_rtc_of_match, |
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}, |
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}; |
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module_platform_driver(cpcap_rtc_driver); |
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MODULE_ALIAS("platform:cpcap-rtc"); |
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MODULE_DESCRIPTION("CPCAP RTC driver"); |
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MODULE_AUTHOR("Sebastian Reichel <[email protected]>"); |
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MODULE_LICENSE("GPL");
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