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alistair23-linux/drivers/rtc/rtc-88pm860x.c
Colin Ian King dc9e471606 rtc: 88pm860x: fix unintended sign extension 
Shifting a u8 by 24 will cause the value to be promoted to an integer. If
the top bit of the u8 is set then the following conversion to an unsigned
long will sign extend the value causing the upper 32 bits to be set in
the result.

Fix this by casting the u8 value to an unsigned long before the shift.

Detected by CoverityScan, CID#144925-144928 ("Unintended sign extension")

Fixes: 008b30408c ("mfd: Add rtc support to 88pm860x")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2019-02-08 09:30:13 +01:00

469 lines
13 KiB
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/*
* Real Time Clock driver for Marvell 88PM860x PMIC
*
* Copyright (c) 2010 Marvell International Ltd.
* Author: Haojian Zhuang <haojian.zhuang@marvell.com>
*
* 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.
*/
#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;
int (*sync)(unsigned int ticks);
};
#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;
}
/*
* Calculate the next alarm time given the requested alarm time mask
* and the current time.
*/
static void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now,
struct rtc_time *alrm)
{
unsigned long next_time;
unsigned long now_time;
next->tm_year = now->tm_year;
next->tm_mon = now->tm_mon;
next->tm_mday = now->tm_mday;
next->tm_hour = alrm->tm_hour;
next->tm_min = alrm->tm_min;
next->tm_sec = alrm->tm_sec;
rtc_tm_to_time(now, &now_time);
rtc_tm_to_time(next, &next_time);
if (next_time < now_time) {
/* Advance one day */
next_time += 60 * 60 * 24;
rtc_time_to_tm(next_time, next);
}
}
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_time_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;
if (tm->tm_year > 206) {
dev_dbg(info->dev, "Set time %d out of range. "
"Please set time between 1970 to 2106.\n",
1900 + tm->tm_year);
return -EINVAL;
}
rtc_tm_to_time(tm, &ticks);
/* 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);
if (info->sync)
info->sync(ticks);
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_time_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);
struct rtc_time now_tm, alarm_tm;
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];
/* 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_time_to_tm(ticks, &now_tm);
rtc_next_alarm_time(&alarm_tm, &now_tm, &alrm->time);
/* get new ticks for alarm in 24 hours */
rtc_tm_to_time(&alarm_tm, &ticks);
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) (-1)
#endif
static int pm860x_rtc_probe(struct platform_device *pdev)
{
struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
struct pm860x_rtc_pdata *pdata = NULL;
struct pm860x_rtc_info *info;
struct rtc_time tm;
unsigned long ticks = 0;
int ret;
pdata = dev_get_platdata(&pdev->dev);
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) {
dev_err(&pdev->dev, "No IRQ resource!\n");
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);
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);
ret = pm860x_rtc_read_time(&pdev->dev, &tm);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to read initial time.\n");
return ret;
}
if ((tm.tm_year < 70) || (tm.tm_year > 138)) {
tm.tm_year = 70;
tm.tm_mon = 0;
tm.tm_mday = 1;
tm.tm_hour = 0;
tm.tm_min = 0;
tm.tm_sec = 0;
ret = pm860x_rtc_set_time(&pdev->dev, &tm);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to set initial time.\n");
return ret;
}
}
rtc_tm_to_time(&tm, &ticks);
if (pm860x_rtc_dt_init(pdev, info)) {
if (pdata && pdata->sync) {
pdata->sync(ticks);
info->sync = pdata->sync;
}
}
info->rtc_dev = devm_rtc_device_register(&pdev->dev, "88pm860x-rtc",
&pm860x_rtc_ops, THIS_MODULE);
ret = PTR_ERR(info->rtc_dev);
if (IS_ERR(info->rtc_dev)) {
dev_err(&pdev->dev, "Failed to register RTC device: %d\n", 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 */
if (pm860x_rtc_dt_init(pdev, info)) {
if (pdata && pdata->vrtc)
info->vrtc = pdata->vrtc & 0x3;
else
info->vrtc = 1;
}
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
flush_scheduled_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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