mirror of
https://github.com/torvalds/linux.git
synced 2024-11-10 22:21:40 +00:00
rtc: rv8803: Always apply the I²C workaround
The I²C NACK issue of the RV-8803 may occur after any I²C START condition, depending on the timings. Consequently, the workaround must be applied for all the I²C transfers. This commit abstracts the I²C transfer code into register access functions. This avoids duplicating the I²C workaround everywhere. This also avoids the duplication of the code handling the return value of i2c_smbus_read_i2c_block_data(). Error messages are issued in case of definitive register access failures (if the workaround fails). This change also makes the I²C transfer return value checks consistent. Signed-off-by: Benoît Thébaudeau <benoit@wsystem.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
This commit is contained in:
Benoît Thébaudeau
Alexandre Belloni
parent
a1e98e0970
commit
d522649e26
@ -20,6 +20,8 @@
|
||||
#include <linux/module.h>
|
||||
#include <linux/rtc.h>
|
||||
|
||||
#define RV8803_I2C_TRY_COUNT 4
|
||||
|
||||
#define RV8803_SEC 0x00
|
||||
#define RV8803_MIN 0x01
|
||||
#define RV8803_HOUR 0x02
|
||||
@ -57,19 +59,85 @@ struct rv8803_data {
|
||||
u8 ctrl;
|
||||
};
|
||||
|
||||
static int rv8803_read_reg(const struct i2c_client *client, u8 reg)
|
||||
{
|
||||
int try = RV8803_I2C_TRY_COUNT;
|
||||
s32 ret;
|
||||
|
||||
/*
|
||||
* There is a 61µs window during which the RTC does not acknowledge I2C
|
||||
* transfers. In that case, ensure that there are multiple attempts.
|
||||
*/
|
||||
do
|
||||
ret = i2c_smbus_read_byte_data(client, reg);
|
||||
while ((ret == -ENXIO || ret == -EIO) && --try);
|
||||
if (ret < 0)
|
||||
dev_err(&client->dev, "Unable to read register 0x%02x\n", reg);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int rv8803_read_regs(const struct i2c_client *client,
|
||||
u8 reg, u8 count, u8 *values)
|
||||
{
|
||||
int try = RV8803_I2C_TRY_COUNT;
|
||||
s32 ret;
|
||||
|
||||
do
|
||||
ret = i2c_smbus_read_i2c_block_data(client, reg, count, values);
|
||||
while ((ret == -ENXIO || ret == -EIO) && --try);
|
||||
if (ret != count) {
|
||||
dev_err(&client->dev,
|
||||
"Unable to read registers 0x%02x..0x%02x\n",
|
||||
reg, reg + count - 1);
|
||||
return ret < 0 ? ret : -EIO;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int rv8803_write_reg(const struct i2c_client *client, u8 reg, u8 value)
|
||||
{
|
||||
int try = RV8803_I2C_TRY_COUNT;
|
||||
s32 ret;
|
||||
|
||||
do
|
||||
ret = i2c_smbus_write_byte_data(client, reg, value);
|
||||
while ((ret == -ENXIO || ret == -EIO) && --try);
|
||||
if (ret)
|
||||
dev_err(&client->dev, "Unable to write register 0x%02x\n", reg);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int rv8803_write_regs(const struct i2c_client *client,
|
||||
u8 reg, u8 count, const u8 *values)
|
||||
{
|
||||
int try = RV8803_I2C_TRY_COUNT;
|
||||
s32 ret;
|
||||
|
||||
do
|
||||
ret = i2c_smbus_write_i2c_block_data(client, reg, count,
|
||||
values);
|
||||
while ((ret == -ENXIO || ret == -EIO) && --try);
|
||||
if (ret)
|
||||
dev_err(&client->dev,
|
||||
"Unable to write registers 0x%02x..0x%02x\n",
|
||||
reg, reg + count - 1);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static irqreturn_t rv8803_handle_irq(int irq, void *dev_id)
|
||||
{
|
||||
struct i2c_client *client = dev_id;
|
||||
struct rv8803_data *rv8803 = i2c_get_clientdata(client);
|
||||
unsigned long events = 0;
|
||||
int flags, try = 0;
|
||||
int flags;
|
||||
|
||||
mutex_lock(&rv8803->flags_lock);
|
||||
|
||||
do {
|
||||
flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
|
||||
try++;
|
||||
} while (((flags == -ENXIO) || (flags == -EIO)) && (try < 4));
|
||||
flags = rv8803_read_reg(client, RV8803_FLAG);
|
||||
if (flags <= 0) {
|
||||
mutex_unlock(&rv8803->flags_lock);
|
||||
return IRQ_NONE;
|
||||
@ -101,9 +169,8 @@ static irqreturn_t rv8803_handle_irq(int irq, void *dev_id)
|
||||
|
||||
if (events) {
|
||||
rtc_update_irq(rv8803->rtc, 1, events);
|
||||
i2c_smbus_write_byte_data(client, RV8803_FLAG, flags);
|
||||
i2c_smbus_write_byte_data(rv8803->client, RV8803_CTRL,
|
||||
rv8803->ctrl);
|
||||
rv8803_write_reg(client, RV8803_FLAG, flags);
|
||||
rv8803_write_reg(rv8803->client, RV8803_CTRL, rv8803->ctrl);
|
||||
}
|
||||
|
||||
mutex_unlock(&rv8803->flags_lock);
|
||||
@ -119,7 +186,7 @@ static int rv8803_get_time(struct device *dev, struct rtc_time *tm)
|
||||
u8 *date = date1;
|
||||
int ret, flags;
|
||||
|
||||
flags = i2c_smbus_read_byte_data(rv8803->client, RV8803_FLAG);
|
||||
flags = rv8803_read_reg(rv8803->client, RV8803_FLAG);
|
||||
if (flags < 0)
|
||||
return flags;
|
||||
|
||||
@ -128,16 +195,14 @@ static int rv8803_get_time(struct device *dev, struct rtc_time *tm)
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
ret = i2c_smbus_read_i2c_block_data(rv8803->client, RV8803_SEC,
|
||||
7, date);
|
||||
if (ret != 7)
|
||||
return ret < 0 ? ret : -EIO;
|
||||
ret = rv8803_read_regs(rv8803->client, RV8803_SEC, 7, date);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
if ((date1[RV8803_SEC] & 0x7f) == bin2bcd(59)) {
|
||||
ret = i2c_smbus_read_i2c_block_data(rv8803->client, RV8803_SEC,
|
||||
7, date2);
|
||||
if (ret != 7)
|
||||
return ret < 0 ? ret : -EIO;
|
||||
ret = rv8803_read_regs(rv8803->client, RV8803_SEC, 7, date2);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
if ((date2[RV8803_SEC] & 0x7f) != bin2bcd(59))
|
||||
date = date2;
|
||||
@ -171,21 +236,20 @@ static int rv8803_set_time(struct device *dev, struct rtc_time *tm)
|
||||
date[RV8803_MONTH] = bin2bcd(tm->tm_mon + 1);
|
||||
date[RV8803_YEAR] = bin2bcd(tm->tm_year - 100);
|
||||
|
||||
ret = i2c_smbus_write_i2c_block_data(rv8803->client, RV8803_SEC,
|
||||
7, date);
|
||||
if (ret < 0)
|
||||
ret = rv8803_write_regs(rv8803->client, RV8803_SEC, 7, date);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
mutex_lock(&rv8803->flags_lock);
|
||||
|
||||
flags = i2c_smbus_read_byte_data(rv8803->client, RV8803_FLAG);
|
||||
flags = rv8803_read_reg(rv8803->client, RV8803_FLAG);
|
||||
if (flags < 0) {
|
||||
mutex_unlock(&rv8803->flags_lock);
|
||||
return flags;
|
||||
}
|
||||
|
||||
ret = i2c_smbus_write_byte_data(rv8803->client, RV8803_FLAG,
|
||||
flags & ~RV8803_FLAG_V2F);
|
||||
ret = rv8803_write_reg(rv8803->client, RV8803_FLAG,
|
||||
flags & ~RV8803_FLAG_V2F);
|
||||
|
||||
mutex_unlock(&rv8803->flags_lock);
|
||||
|
||||
@ -199,12 +263,11 @@ static int rv8803_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
|
||||
u8 alarmvals[3];
|
||||
int flags, ret;
|
||||
|
||||
ret = i2c_smbus_read_i2c_block_data(client, RV8803_ALARM_MIN,
|
||||
3, alarmvals);
|
||||
if (ret != 3)
|
||||
return ret < 0 ? ret : -EIO;
|
||||
ret = rv8803_read_regs(client, RV8803_ALARM_MIN, 3, alarmvals);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
|
||||
flags = rv8803_read_reg(client, RV8803_FLAG);
|
||||
if (flags < 0)
|
||||
return flags;
|
||||
|
||||
@ -237,10 +300,10 @@ static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
|
||||
|
||||
mutex_lock(&rv8803->flags_lock);
|
||||
|
||||
ret = i2c_smbus_read_i2c_block_data(client, RV8803_FLAG, 2, ctrl);
|
||||
if (ret != 2) {
|
||||
ret = rv8803_read_regs(client, RV8803_FLAG, 2, ctrl);
|
||||
if (ret) {
|
||||
mutex_unlock(&rv8803->flags_lock);
|
||||
return ret < 0 ? ret : -EIO;
|
||||
return ret;
|
||||
}
|
||||
|
||||
alarmvals[0] = bin2bcd(alrm->time.tm_min);
|
||||
@ -249,8 +312,8 @@ static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
|
||||
|
||||
if (rv8803->ctrl & (RV8803_CTRL_AIE | RV8803_CTRL_UIE)) {
|
||||
rv8803->ctrl &= ~(RV8803_CTRL_AIE | RV8803_CTRL_UIE);
|
||||
err = i2c_smbus_write_byte_data(rv8803->client, RV8803_CTRL,
|
||||
rv8803->ctrl);
|
||||
err = rv8803_write_reg(rv8803->client, RV8803_CTRL,
|
||||
rv8803->ctrl);
|
||||
if (err) {
|
||||
mutex_unlock(&rv8803->flags_lock);
|
||||
return err;
|
||||
@ -258,13 +321,12 @@ static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
|
||||
}
|
||||
|
||||
ctrl[1] &= ~RV8803_FLAG_AF;
|
||||
err = i2c_smbus_write_byte_data(rv8803->client, RV8803_FLAG, ctrl[1]);
|
||||
err = rv8803_write_reg(rv8803->client, RV8803_FLAG, ctrl[1]);
|
||||
mutex_unlock(&rv8803->flags_lock);
|
||||
if (err)
|
||||
return err;
|
||||
|
||||
err = i2c_smbus_write_i2c_block_data(rv8803->client, RV8803_ALARM_MIN,
|
||||
3, alarmvals);
|
||||
err = rv8803_write_regs(rv8803->client, RV8803_ALARM_MIN, 3, alarmvals);
|
||||
if (err)
|
||||
return err;
|
||||
|
||||
@ -274,8 +336,8 @@ static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
|
||||
if (rv8803->rtc->aie_timer.enabled)
|
||||
rv8803->ctrl |= RV8803_CTRL_AIE;
|
||||
|
||||
err = i2c_smbus_write_byte_data(rv8803->client, RV8803_CTRL,
|
||||
rv8803->ctrl);
|
||||
err = rv8803_write_reg(rv8803->client, RV8803_CTRL,
|
||||
rv8803->ctrl);
|
||||
if (err)
|
||||
return err;
|
||||
}
|
||||
@ -304,21 +366,20 @@ static int rv8803_alarm_irq_enable(struct device *dev, unsigned int enabled)
|
||||
}
|
||||
|
||||
mutex_lock(&rv8803->flags_lock);
|
||||
flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
|
||||
flags = rv8803_read_reg(client, RV8803_FLAG);
|
||||
if (flags < 0) {
|
||||
mutex_unlock(&rv8803->flags_lock);
|
||||
return flags;
|
||||
}
|
||||
flags &= ~(RV8803_FLAG_AF | RV8803_FLAG_UF);
|
||||
err = i2c_smbus_write_byte_data(client, RV8803_FLAG, flags);
|
||||
err = rv8803_write_reg(client, RV8803_FLAG, flags);
|
||||
mutex_unlock(&rv8803->flags_lock);
|
||||
if (err)
|
||||
return err;
|
||||
|
||||
if (ctrl != rv8803->ctrl) {
|
||||
rv8803->ctrl = ctrl;
|
||||
err = i2c_smbus_write_byte_data(client, RV8803_CTRL,
|
||||
rv8803->ctrl);
|
||||
err = rv8803_write_reg(client, RV8803_CTRL, rv8803->ctrl);
|
||||
if (err)
|
||||
return err;
|
||||
}
|
||||
@ -334,7 +395,7 @@ static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
|
||||
|
||||
switch (cmd) {
|
||||
case RTC_VL_READ:
|
||||
flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
|
||||
flags = rv8803_read_reg(client, RV8803_FLAG);
|
||||
if (flags < 0)
|
||||
return flags;
|
||||
|
||||
@ -353,16 +414,16 @@ static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
|
||||
|
||||
case RTC_VL_CLR:
|
||||
mutex_lock(&rv8803->flags_lock);
|
||||
flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
|
||||
flags = rv8803_read_reg(client, RV8803_FLAG);
|
||||
if (flags < 0) {
|
||||
mutex_unlock(&rv8803->flags_lock);
|
||||
return flags;
|
||||
}
|
||||
|
||||
flags &= ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F);
|
||||
ret = i2c_smbus_write_byte_data(client, RV8803_FLAG, flags);
|
||||
ret = rv8803_write_reg(client, RV8803_FLAG, flags);
|
||||
mutex_unlock(&rv8803->flags_lock);
|
||||
if (ret < 0)
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
return 0;
|
||||
@ -380,8 +441,8 @@ static ssize_t rv8803_nvram_write(struct file *filp, struct kobject *kobj,
|
||||
struct i2c_client *client = to_i2c_client(dev);
|
||||
int ret;
|
||||
|
||||
ret = i2c_smbus_write_byte_data(client, RV8803_RAM, buf[0]);
|
||||
if (ret < 0)
|
||||
ret = rv8803_write_reg(client, RV8803_RAM, buf[0]);
|
||||
if (ret)
|
||||
return ret;
|
||||
|
||||
return 1;
|
||||
@ -395,7 +456,7 @@ static ssize_t rv8803_nvram_read(struct file *filp, struct kobject *kobj,
|
||||
struct i2c_client *client = to_i2c_client(dev);
|
||||
int ret;
|
||||
|
||||
ret = i2c_smbus_read_byte_data(client, RV8803_RAM);
|
||||
ret = rv8803_read_reg(client, RV8803_RAM);
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
|
||||
@ -425,7 +486,7 @@ static int rv8803_probe(struct i2c_client *client,
|
||||
{
|
||||
struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
|
||||
struct rv8803_data *rv8803;
|
||||
int err, flags, try = 0;
|
||||
int err, flags;
|
||||
|
||||
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
|
||||
I2C_FUNC_SMBUS_I2C_BLOCK)) {
|
||||
@ -442,16 +503,7 @@ static int rv8803_probe(struct i2c_client *client,
|
||||
rv8803->client = client;
|
||||
i2c_set_clientdata(client, rv8803);
|
||||
|
||||
/*
|
||||
* There is a 60µs window where the RTC may not reply on the i2c bus in
|
||||
* that case, the transfer is not ACKed. In that case, ensure there are
|
||||
* multiple attempts.
|
||||
*/
|
||||
do {
|
||||
flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
|
||||
try++;
|
||||
} while (((flags == -ENXIO) || (flags == -EIO)) && (try < 4));
|
||||
|
||||
flags = rv8803_read_reg(client, RV8803_FLAG);
|
||||
if (flags < 0)
|
||||
return flags;
|
||||
|
||||
@ -486,12 +538,7 @@ static int rv8803_probe(struct i2c_client *client,
|
||||
return PTR_ERR(rv8803->rtc);
|
||||
}
|
||||
|
||||
try = 0;
|
||||
do {
|
||||
err = i2c_smbus_write_byte_data(rv8803->client, RV8803_EXT,
|
||||
RV8803_EXT_WADA);
|
||||
try++;
|
||||
} while (((err == -ENXIO) || (flags == -EIO)) && (try < 4));
|
||||
err = rv8803_write_reg(rv8803->client, RV8803_EXT, RV8803_EXT_WADA);
|
||||
if (err)
|
||||
return err;
|
||||
|
||||
|
||||
Loading…
Reference in New Issue
Block a user