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linux/drivers/rtc/rtc-88pm860x.c
Bartosz Golaszewski fdcfd85433 rtc: rework rtc_register_device() resource management 
rtc_register_device() is a managed interface but it doesn't use devres
by itself - instead it marks an rtc_device as "registered" and the devres
callback for devm_rtc_allocate_device() takes care of resource release.

This doesn't correspond with the design behind devres where managed
structures should not be aware of being managed. The correct solution
here is to register a separate devres callback for unregistering the
device.

While at it: rename rtc_register_device() to devm_rtc_register_device()
and add it to the list of managed interfaces in devres.rst. This way we
can avoid any potential confusion of driver developers who may expect
there to exist a corresponding unregister function.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20201109163409.24301-8-brgl@bgdev.pl
2020-11-19 12:50:12 +01:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Real Time Clock driver for Marvell 88PM860x PMIC
*
* Copyright (c) 2010 Marvell International Ltd.
* Author: Haojian Zhuang <haojian.zhuang@marvell.com>
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/rtc.h>
#include <linux/delay.h>
#include <linux/mfd/core.h>
#include <linux/mfd/88pm860x.h>
#define VRTC_CALIBRATION
struct pm860x_rtc_info {
struct pm860x_chip *chip;
struct i2c_client *i2c;
struct rtc_device *rtc_dev;
struct device *dev;
struct delayed_work calib_work;
int irq;
int vrtc;
};
#define REG_VRTC_MEAS1 0x7D
#define REG0_ADDR 0xB0
#define REG1_ADDR 0xB2
#define REG2_ADDR 0xB4
#define REG3_ADDR 0xB6
#define REG0_DATA 0xB1
#define REG1_DATA 0xB3
#define REG2_DATA 0xB5
#define REG3_DATA 0xB7
/* bit definitions of Measurement Enable Register 2 (0x51) */
#define MEAS2_VRTC (1 << 0)
/* bit definitions of RTC Register 1 (0xA0) */
#define ALARM_EN (1 << 3)
#define ALARM_WAKEUP (1 << 4)
#define ALARM (1 << 5)
#define RTC1_USE_XO (1 << 7)
#define VRTC_CALIB_INTERVAL (HZ * 60 * 10) /* 10 minutes */
static irqreturn_t rtc_update_handler(int irq, void *data)
{
struct pm860x_rtc_info *info = (struct pm860x_rtc_info *)data;
int mask;
mask = ALARM | ALARM_WAKEUP;
pm860x_set_bits(info->i2c, PM8607_RTC1, mask | ALARM_EN, mask);
rtc_update_irq(info->rtc_dev, 1, RTC_AF);
return IRQ_HANDLED;
}
static int pm860x_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct pm860x_rtc_info *info = dev_get_drvdata(dev);
if (enabled)
pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, ALARM_EN);
else
pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0);
return 0;
}
static int pm860x_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct pm860x_rtc_info *info = dev_get_drvdata(dev);
unsigned char buf[8];
unsigned long ticks, base, data;
pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
(buf[5] << 8) | buf[7];
/* load 32-bit read-only counter */
pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
(buf[1] << 8) | buf[0];
ticks = base + data;
dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
base, data, ticks);
rtc_time64_to_tm(ticks, tm);
return 0;
}
static int pm860x_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct pm860x_rtc_info *info = dev_get_drvdata(dev);
unsigned char buf[4];
unsigned long ticks, base, data;
ticks = rtc_tm_to_time64(tm);
/* load 32-bit read-only counter */
pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
(buf[1] << 8) | buf[0];
base = ticks - data;
dev_dbg(info->dev, "set base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
base, data, ticks);
pm860x_page_reg_write(info->i2c, REG0_DATA, (base >> 24) & 0xFF);
pm860x_page_reg_write(info->i2c, REG1_DATA, (base >> 16) & 0xFF);
pm860x_page_reg_write(info->i2c, REG2_DATA, (base >> 8) & 0xFF);
pm860x_page_reg_write(info->i2c, REG3_DATA, base & 0xFF);
return 0;
}
static int pm860x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct pm860x_rtc_info *info = dev_get_drvdata(dev);
unsigned char buf[8];
unsigned long ticks, base, data;
int ret;
pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
(buf[5] << 8) | buf[7];
pm860x_bulk_read(info->i2c, PM8607_RTC_EXPIRE1, 4, buf);
data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
(buf[1] << 8) | buf[0];
ticks = base + data;
dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
base, data, ticks);
rtc_time64_to_tm(ticks, &alrm->time);
ret = pm860x_reg_read(info->i2c, PM8607_RTC1);
alrm->enabled = (ret & ALARM_EN) ? 1 : 0;
alrm->pending = (ret & (ALARM | ALARM_WAKEUP)) ? 1 : 0;
return 0;
}
static int pm860x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct pm860x_rtc_info *info = dev_get_drvdata(dev);
unsigned long ticks, base, data;
unsigned char buf[8];
int mask;
pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0);
pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
(buf[5] << 8) | buf[7];
ticks = rtc_tm_to_time64(&alrm->time);
data = ticks - base;
buf[0] = data & 0xff;
buf[1] = (data >> 8) & 0xff;
buf[2] = (data >> 16) & 0xff;
buf[3] = (data >> 24) & 0xff;
pm860x_bulk_write(info->i2c, PM8607_RTC_EXPIRE1, 4, buf);
if (alrm->enabled) {
mask = ALARM | ALARM_WAKEUP | ALARM_EN;
pm860x_set_bits(info->i2c, PM8607_RTC1, mask, mask);
} else {
mask = ALARM | ALARM_WAKEUP | ALARM_EN;
pm860x_set_bits(info->i2c, PM8607_RTC1, mask,
ALARM | ALARM_WAKEUP);
}
return 0;
}
static const struct rtc_class_ops pm860x_rtc_ops = {
.read_time = pm860x_rtc_read_time,
.set_time = pm860x_rtc_set_time,
.read_alarm = pm860x_rtc_read_alarm,
.set_alarm = pm860x_rtc_set_alarm,
.alarm_irq_enable = pm860x_rtc_alarm_irq_enable,
};
#ifdef VRTC_CALIBRATION
static void calibrate_vrtc_work(struct work_struct *work)
{
struct pm860x_rtc_info *info = container_of(work,
struct pm860x_rtc_info, calib_work.work);
unsigned char buf[2];
unsigned int sum, data, mean, vrtc_set;
int i;
for (i = 0, sum = 0; i < 16; i++) {
msleep(100);
pm860x_bulk_read(info->i2c, REG_VRTC_MEAS1, 2, buf);
data = (buf[0] << 4) | buf[1];
data = (data * 5400) >> 12; /* convert to mv */
sum += data;
}
mean = sum >> 4;
vrtc_set = 2700 + (info->vrtc & 0x3) * 200;
dev_dbg(info->dev, "mean:%d, vrtc_set:%d\n", mean, vrtc_set);
sum = pm860x_reg_read(info->i2c, PM8607_RTC_MISC1);
data = sum & 0x3;
if ((mean + 200) < vrtc_set) {
/* try higher voltage */
if (++data == 4)
goto out;
data = (sum & 0xf8) | (data & 0x3);
pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data);
} else if ((mean - 200) > vrtc_set) {
/* try lower voltage */
if (data-- == 0)
goto out;
data = (sum & 0xf8) | (data & 0x3);
pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data);
} else
goto out;
dev_dbg(info->dev, "set 0x%x to RTC_MISC1\n", data);
/* trigger next calibration since VRTC is updated */
schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL);
return;
out:
/* disable measurement */
pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0);
dev_dbg(info->dev, "finish VRTC calibration\n");
return;
}
#endif
#ifdef CONFIG_OF
static int pm860x_rtc_dt_init(struct platform_device *pdev,
struct pm860x_rtc_info *info)
{
struct device_node *np = pdev->dev.parent->of_node;
int ret;
if (!np)
return -ENODEV;
np = of_get_child_by_name(np, "rtc");
if (!np) {
dev_err(&pdev->dev, "failed to find rtc node\n");
return -ENODEV;
}
ret = of_property_read_u32(np, "marvell,88pm860x-vrtc", &info->vrtc);
if (ret)
info->vrtc = 0;
of_node_put(np);
return 0;
}
#else
#define pm860x_rtc_dt_init(x, y) do { } while (0)
#endif
static int pm860x_rtc_probe(struct platform_device *pdev)
{
struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
struct pm860x_rtc_info *info;
int ret;
info = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_rtc_info),
GFP_KERNEL);
if (!info)
return -ENOMEM;
info->irq = platform_get_irq(pdev, 0);
if (info->irq < 0)
return info->irq;
info->chip = chip;
info->i2c = (chip->id == CHIP_PM8607) ? chip->client : chip->companion;
info->dev = &pdev->dev;
dev_set_drvdata(&pdev->dev, info);
info->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
if (IS_ERR(info->rtc_dev))
return PTR_ERR(info->rtc_dev);
ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
rtc_update_handler, IRQF_ONESHOT, "rtc",
info);
if (ret < 0) {
dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
info->irq, ret);
return ret;
}
/* set addresses of 32-bit base value for RTC time */
pm860x_page_reg_write(info->i2c, REG0_ADDR, REG0_DATA);
pm860x_page_reg_write(info->i2c, REG1_ADDR, REG1_DATA);
pm860x_page_reg_write(info->i2c, REG2_ADDR, REG2_DATA);
pm860x_page_reg_write(info->i2c, REG3_ADDR, REG3_DATA);
pm860x_rtc_dt_init(pdev, info);
info->rtc_dev->ops = &pm860x_rtc_ops;
info->rtc_dev->range_max = U32_MAX;
ret = devm_rtc_register_device(info->rtc_dev);
if (ret)
return ret;
/*
* enable internal XO instead of internal 3.25MHz clock since it can
* free running in PMIC power-down state.
*/
pm860x_set_bits(info->i2c, PM8607_RTC1, RTC1_USE_XO, RTC1_USE_XO);
#ifdef VRTC_CALIBRATION
/* <00> -- 2.7V, <01> -- 2.9V, <10> -- 3.1V, <11> -- 3.3V */
pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, MEAS2_VRTC);
/* calibrate VRTC */
INIT_DELAYED_WORK(&info->calib_work, calibrate_vrtc_work);
schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL);
#endif /* VRTC_CALIBRATION */
device_init_wakeup(&pdev->dev, 1);
return 0;
}
static int pm860x_rtc_remove(struct platform_device *pdev)
{
struct pm860x_rtc_info *info = platform_get_drvdata(pdev);
#ifdef VRTC_CALIBRATION
cancel_delayed_work_sync(&info->calib_work);
/* disable measurement */
pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0);
#endif /* VRTC_CALIBRATION */
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int pm860x_rtc_suspend(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
if (device_may_wakeup(dev))
chip->wakeup_flag |= 1 << PM8607_IRQ_RTC;
return 0;
}
static int pm860x_rtc_resume(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
if (device_may_wakeup(dev))
chip->wakeup_flag &= ~(1 << PM8607_IRQ_RTC);
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(pm860x_rtc_pm_ops, pm860x_rtc_suspend, pm860x_rtc_resume);
static struct platform_driver pm860x_rtc_driver = {
.driver = {
.name = "88pm860x-rtc",
.pm = &pm860x_rtc_pm_ops,
},
.probe = pm860x_rtc_probe,
.remove = pm860x_rtc_remove,
};
module_platform_driver(pm860x_rtc_driver);
MODULE_DESCRIPTION("Marvell 88PM860x RTC driver");
MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
MODULE_LICENSE("GPL");
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