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linux-stable/drivers/rtc/rtc-rx8010.c
Bartosz Golaszewski d3b14296da rtc: rx8010: don't modify the global rtc ops 
The way the driver is implemented is buggy for the (admittedly unlikely)
use case where there are two RTCs with one having an interrupt configured
and the second not. This is caused by the fact that we use a global
rtc_class_ops struct which we modify depending on whether the irq number
is present or not.

Fix it by using two const ops structs with and without alarm operations.
While at it: not being able to request a configured interrupt is an error
so don't ignore it and bail out of probe().

Fixes: ed13d89b08 ("rtc: Add Epson RX8010SJ RTC driver")
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200914154601.32245-2-brgl@bgdev.pl
2020-09-15 10:50:37 +02:00

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Driver for the Epson RTC module RX-8010 SJ
*
* Copyright(C) Timesys Corporation 2015
* Copyright(C) General Electric Company 2015
*/
#include <linux/bcd.h>
#include <linux/bitops.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rtc.h>
#define RX8010_SEC 0x10
#define RX8010_MIN 0x11
#define RX8010_HOUR 0x12
#define RX8010_WDAY 0x13
#define RX8010_MDAY 0x14
#define RX8010_MONTH 0x15
#define RX8010_YEAR 0x16
#define RX8010_RESV17 0x17
#define RX8010_ALMIN 0x18
#define RX8010_ALHOUR 0x19
#define RX8010_ALWDAY 0x1A
#define RX8010_TCOUNT0 0x1B
#define RX8010_TCOUNT1 0x1C
#define RX8010_EXT 0x1D
#define RX8010_FLAG 0x1E
#define RX8010_CTRL 0x1F
/* 0x20 to 0x2F are user registers */
#define RX8010_RESV30 0x30
#define RX8010_RESV31 0x31
#define RX8010_IRQ 0x32
#define RX8010_EXT_WADA BIT(3)
#define RX8010_FLAG_VLF BIT(1)
#define RX8010_FLAG_AF BIT(3)
#define RX8010_FLAG_TF BIT(4)
#define RX8010_FLAG_UF BIT(5)
#define RX8010_CTRL_AIE BIT(3)
#define RX8010_CTRL_UIE BIT(5)
#define RX8010_CTRL_STOP BIT(6)
#define RX8010_CTRL_TEST BIT(7)
#define RX8010_ALARM_AE BIT(7)
static const struct i2c_device_id rx8010_id[] = {
{ "rx8010", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, rx8010_id);
static const struct of_device_id rx8010_of_match[] = {
{ .compatible = "epson,rx8010" },
{ }
};
MODULE_DEVICE_TABLE(of, rx8010_of_match);
struct rx8010_data {
struct i2c_client *client;
struct rtc_device *rtc;
u8 ctrlreg;
};
static irqreturn_t rx8010_irq_1_handler(int irq, void *dev_id)
{
struct i2c_client *client = dev_id;
struct rx8010_data *rx8010 = i2c_get_clientdata(client);
int flagreg;
mutex_lock(&rx8010->rtc->ops_lock);
flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
if (flagreg <= 0) {
mutex_unlock(&rx8010->rtc->ops_lock);
return IRQ_NONE;
}
if (flagreg & RX8010_FLAG_VLF)
dev_warn(&client->dev, "Frequency stop detected\n");
if (flagreg & RX8010_FLAG_TF) {
flagreg &= ~RX8010_FLAG_TF;
rtc_update_irq(rx8010->rtc, 1, RTC_PF | RTC_IRQF);
}
if (flagreg & RX8010_FLAG_AF) {
flagreg &= ~RX8010_FLAG_AF;
rtc_update_irq(rx8010->rtc, 1, RTC_AF | RTC_IRQF);
}
if (flagreg & RX8010_FLAG_UF) {
flagreg &= ~RX8010_FLAG_UF;
rtc_update_irq(rx8010->rtc, 1, RTC_UF | RTC_IRQF);
}
i2c_smbus_write_byte_data(client, RX8010_FLAG, flagreg);
mutex_unlock(&rx8010->rtc->ops_lock);
return IRQ_HANDLED;
}
static int rx8010_get_time(struct device *dev, struct rtc_time *dt)
{
struct rx8010_data *rx8010 = dev_get_drvdata(dev);
u8 date[7];
int flagreg;
int err;
flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
if (flagreg < 0)
return flagreg;
if (flagreg & RX8010_FLAG_VLF) {
dev_warn(dev, "Frequency stop detected\n");
return -EINVAL;
}
err = i2c_smbus_read_i2c_block_data(rx8010->client, RX8010_SEC,
7, date);
if (err != 7)
return err < 0 ? err : -EIO;
dt->tm_sec = bcd2bin(date[RX8010_SEC - RX8010_SEC] & 0x7f);
dt->tm_min = bcd2bin(date[RX8010_MIN - RX8010_SEC] & 0x7f);
dt->tm_hour = bcd2bin(date[RX8010_HOUR - RX8010_SEC] & 0x3f);
dt->tm_mday = bcd2bin(date[RX8010_MDAY - RX8010_SEC] & 0x3f);
dt->tm_mon = bcd2bin(date[RX8010_MONTH - RX8010_SEC] & 0x1f) - 1;
dt->tm_year = bcd2bin(date[RX8010_YEAR - RX8010_SEC]) + 100;
dt->tm_wday = ffs(date[RX8010_WDAY - RX8010_SEC] & 0x7f);
return 0;
}
static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
{
struct rx8010_data *rx8010 = dev_get_drvdata(dev);
u8 date[7];
int ctrl, flagreg;
int ret;
if ((dt->tm_year < 100) || (dt->tm_year > 199))
return -EINVAL;
/* set STOP bit before changing clock/calendar */
ctrl = i2c_smbus_read_byte_data(rx8010->client, RX8010_CTRL);
if (ctrl < 0)
return ctrl;
rx8010->ctrlreg = ctrl | RX8010_CTRL_STOP;
ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
rx8010->ctrlreg);
if (ret < 0)
return ret;
date[RX8010_SEC - RX8010_SEC] = bin2bcd(dt->tm_sec);
date[RX8010_MIN - RX8010_SEC] = bin2bcd(dt->tm_min);
date[RX8010_HOUR - RX8010_SEC] = bin2bcd(dt->tm_hour);
date[RX8010_MDAY - RX8010_SEC] = bin2bcd(dt->tm_mday);
date[RX8010_MONTH - RX8010_SEC] = bin2bcd(dt->tm_mon + 1);
date[RX8010_YEAR - RX8010_SEC] = bin2bcd(dt->tm_year - 100);
date[RX8010_WDAY - RX8010_SEC] = bin2bcd(1 << dt->tm_wday);
ret = i2c_smbus_write_i2c_block_data(rx8010->client,
RX8010_SEC, 7, date);
if (ret < 0)
return ret;
/* clear STOP bit after changing clock/calendar */
ctrl = i2c_smbus_read_byte_data(rx8010->client, RX8010_CTRL);
if (ctrl < 0)
return ctrl;
rx8010->ctrlreg = ctrl & ~RX8010_CTRL_STOP;
ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
rx8010->ctrlreg);
if (ret < 0)
return ret;
flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
if (flagreg < 0) {
return flagreg;
}
if (flagreg & RX8010_FLAG_VLF)
ret = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG,
flagreg & ~RX8010_FLAG_VLF);
return 0;
}
static int rx8010_init_client(struct i2c_client *client)
{
struct rx8010_data *rx8010 = i2c_get_clientdata(client);
u8 ctrl[2];
int need_clear = 0, err = 0;
/* Initialize reserved registers as specified in datasheet */
err = i2c_smbus_write_byte_data(client, RX8010_RESV17, 0xD8);
if (err < 0)
return err;
err = i2c_smbus_write_byte_data(client, RX8010_RESV30, 0x00);
if (err < 0)
return err;
err = i2c_smbus_write_byte_data(client, RX8010_RESV31, 0x08);
if (err < 0)
return err;
err = i2c_smbus_write_byte_data(client, RX8010_IRQ, 0x00);
if (err < 0)
return err;
err = i2c_smbus_read_i2c_block_data(rx8010->client, RX8010_FLAG,
2, ctrl);
if (err != 2)
return err < 0 ? err : -EIO;
if (ctrl[0] & RX8010_FLAG_VLF)
dev_warn(&client->dev, "Frequency stop was detected\n");
if (ctrl[0] & RX8010_FLAG_AF) {
dev_warn(&client->dev, "Alarm was detected\n");
need_clear = 1;
}
if (ctrl[0] & RX8010_FLAG_TF)
need_clear = 1;
if (ctrl[0] & RX8010_FLAG_UF)
need_clear = 1;
if (need_clear) {
ctrl[0] &= ~(RX8010_FLAG_AF | RX8010_FLAG_TF | RX8010_FLAG_UF);
err = i2c_smbus_write_byte_data(client, RX8010_FLAG, ctrl[0]);
if (err < 0)
return err;
}
rx8010->ctrlreg = (ctrl[1] & ~RX8010_CTRL_TEST);
return 0;
}
static int rx8010_read_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct rx8010_data *rx8010 = dev_get_drvdata(dev);
struct i2c_client *client = rx8010->client;
u8 alarmvals[3];
int flagreg;
int err;
err = i2c_smbus_read_i2c_block_data(client, RX8010_ALMIN, 3, alarmvals);
if (err != 3)
return err < 0 ? err : -EIO;
flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
if (flagreg < 0)
return flagreg;
t->time.tm_sec = 0;
t->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
t->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
if (!(alarmvals[2] & RX8010_ALARM_AE))
t->time.tm_mday = bcd2bin(alarmvals[2] & 0x7f);
t->enabled = !!(rx8010->ctrlreg & RX8010_CTRL_AIE);
t->pending = (flagreg & RX8010_FLAG_AF) && t->enabled;
return 0;
}
static int rx8010_set_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct i2c_client *client = to_i2c_client(dev);
struct rx8010_data *rx8010 = dev_get_drvdata(dev);
u8 alarmvals[3];
int extreg, flagreg;
int err;
flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
if (flagreg < 0) {
return flagreg;
}
if (rx8010->ctrlreg & (RX8010_CTRL_AIE | RX8010_CTRL_UIE)) {
rx8010->ctrlreg &= ~(RX8010_CTRL_AIE | RX8010_CTRL_UIE);
err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
rx8010->ctrlreg);
if (err < 0) {
return err;
}
}
flagreg &= ~RX8010_FLAG_AF;
err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg);
if (err < 0)
return err;
alarmvals[0] = bin2bcd(t->time.tm_min);
alarmvals[1] = bin2bcd(t->time.tm_hour);
alarmvals[2] = bin2bcd(t->time.tm_mday);
err = i2c_smbus_write_i2c_block_data(rx8010->client, RX8010_ALMIN,
2, alarmvals);
if (err < 0)
return err;
extreg = i2c_smbus_read_byte_data(client, RX8010_EXT);
if (extreg < 0)
return extreg;
extreg |= RX8010_EXT_WADA;
err = i2c_smbus_write_byte_data(rx8010->client, RX8010_EXT, extreg);
if (err < 0)
return err;
if (alarmvals[2] == 0)
alarmvals[2] |= RX8010_ALARM_AE;
err = i2c_smbus_write_byte_data(rx8010->client, RX8010_ALWDAY,
alarmvals[2]);
if (err < 0)
return err;
if (t->enabled) {
if (rx8010->rtc->uie_rtctimer.enabled)
rx8010->ctrlreg |= RX8010_CTRL_UIE;
if (rx8010->rtc->aie_timer.enabled)
rx8010->ctrlreg |=
(RX8010_CTRL_AIE | RX8010_CTRL_UIE);
err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
rx8010->ctrlreg);
if (err < 0)
return err;
}
return 0;
}
static int rx8010_alarm_irq_enable(struct device *dev,
unsigned int enabled)
{
struct i2c_client *client = to_i2c_client(dev);
struct rx8010_data *rx8010 = dev_get_drvdata(dev);
int flagreg;
u8 ctrl;
int err;
ctrl = rx8010->ctrlreg;
if (enabled) {
if (rx8010->rtc->uie_rtctimer.enabled)
ctrl |= RX8010_CTRL_UIE;
if (rx8010->rtc->aie_timer.enabled)
ctrl |= (RX8010_CTRL_AIE | RX8010_CTRL_UIE);
} else {
if (!rx8010->rtc->uie_rtctimer.enabled)
ctrl &= ~RX8010_CTRL_UIE;
if (!rx8010->rtc->aie_timer.enabled)
ctrl &= ~RX8010_CTRL_AIE;
}
flagreg = i2c_smbus_read_byte_data(client, RX8010_FLAG);
if (flagreg < 0)
return flagreg;
flagreg &= ~RX8010_FLAG_AF;
err = i2c_smbus_write_byte_data(rx8010->client, RX8010_FLAG, flagreg);
if (err < 0)
return err;
if (ctrl != rx8010->ctrlreg) {
rx8010->ctrlreg = ctrl;
err = i2c_smbus_write_byte_data(rx8010->client, RX8010_CTRL,
rx8010->ctrlreg);
if (err < 0)
return err;
}
return 0;
}
static int rx8010_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
struct rx8010_data *rx8010 = dev_get_drvdata(dev);
int tmp;
int flagreg;
switch (cmd) {
case RTC_VL_READ:
flagreg = i2c_smbus_read_byte_data(rx8010->client, RX8010_FLAG);
if (flagreg < 0)
return flagreg;
tmp = flagreg & RX8010_FLAG_VLF ? RTC_VL_DATA_INVALID : 0;
return put_user(tmp, (unsigned int __user *)arg);
default:
return -ENOIOCTLCMD;
}
}
static const struct rtc_class_ops rx8010_rtc_ops_default = {
.read_time = rx8010_get_time,
.set_time = rx8010_set_time,
.ioctl = rx8010_ioctl,
};
static const struct rtc_class_ops rx8010_rtc_ops_alarm = {
.read_time = rx8010_get_time,
.set_time = rx8010_set_time,
.ioctl = rx8010_ioctl,
.read_alarm = rx8010_read_alarm,
.set_alarm = rx8010_set_alarm,
.alarm_irq_enable = rx8010_alarm_irq_enable,
};
static int rx8010_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct i2c_adapter *adapter = client->adapter;
const struct rtc_class_ops *rtc_ops;
struct rx8010_data *rx8010;
int err = 0;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
| I2C_FUNC_SMBUS_I2C_BLOCK)) {
dev_err(&adapter->dev, "doesn't support required functionality\n");
return -EIO;
}
rx8010 = devm_kzalloc(&client->dev, sizeof(struct rx8010_data),
GFP_KERNEL);
if (!rx8010)
return -ENOMEM;
rx8010->client = client;
i2c_set_clientdata(client, rx8010);
err = rx8010_init_client(client);
if (err)
return err;
if (client->irq > 0) {
dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
rx8010_irq_1_handler,
IRQF_TRIGGER_LOW | IRQF_ONESHOT,
"rx8010", client);
if (err) {
dev_err(&client->dev, "unable to request IRQ\n");
return err;
}
rtc_ops = &rx8010_rtc_ops_alarm;
} else {
rtc_ops = &rx8010_rtc_ops_default;
}
rx8010->rtc = devm_rtc_device_register(&client->dev, client->name,
rtc_ops, THIS_MODULE);
if (IS_ERR(rx8010->rtc)) {
dev_err(&client->dev, "unable to register the class device\n");
return PTR_ERR(rx8010->rtc);
}
rx8010->rtc->max_user_freq = 1;
return 0;
}
static struct i2c_driver rx8010_driver = {
.driver = {
.name = "rtc-rx8010",
.of_match_table = of_match_ptr(rx8010_of_match),
},
.probe = rx8010_probe,
.id_table = rx8010_id,
};
module_i2c_driver(rx8010_driver);
MODULE_AUTHOR("Akshay Bhat <akshay.bhat@timesys.com>");
MODULE_DESCRIPTION("Epson RX8010SJ RTC driver");
MODULE_LICENSE("GPL v2");
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