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linux/drivers/rtc/rtc-cpcap.c
Thomas Gleixner 1802d0beec treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 
Based on 1 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 version 2 as
  published by the free software foundation 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-only

has been chosen to replace the boilerplate/reference in 655 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:41 -07:00

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