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rtc: rv3029: correctly handle PON and VLOW2

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In case the data is invalid (PON or VLOW2 are set in STATUS, explicitly
tell userspace that the time is invalid. Only remove VLOW2 when setting a
new valid time.

Link: https://lore.kernel.org/r/20191214221022.622482-12-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Alexandre Belloni 2019-12-14 23:10:17 +01:00
parent f630f728a9
commit cff2e4d278
1 changed files with 15 additions and 6 deletions
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21
drivers/rtc/rtc-rv3029c2.c
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@ -159,20 +159,21 @@ static int rv3029_eeprom_enter(struct rv3029_data *rv3029)
ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
if (ret < 0)
return ret;
if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
if (sr & RV3029_STATUS_VLOW2)
return -ENODEV;
if (sr & RV3029_STATUS_VLOW1) {
/* We clear the bits and retry once just in case
* we had a brown out in early startup.
*/
ret = regmap_update_bits(rv3029->regmap, RV3029_STATUS,
RV3029_STATUS_VLOW1 |
RV3029_STATUS_VLOW2, 0);
RV3029_STATUS_VLOW1, 0);
if (ret < 0)
return ret;
usleep_range(1000, 10000);
ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
if (ret < 0)
return ret;
if (sr & (RV3029_STATUS_VLOW1 | RV3029_STATUS_VLOW2)) {
if (sr & RV3029_STATUS_VLOW1) {
dev_err(rv3029->dev,
"Supply voltage is too low to safely access the EEPROM.\n");
return -ENODEV;
@ -306,9 +307,17 @@ static irqreturn_t rv3029_handle_irq(int irq, void *dev_id)
static int rv3029_read_time(struct device *dev, struct rtc_time *tm)
{
struct rv3029_data *rv3029 = dev_get_drvdata(dev);
unsigned int sr;
int ret;
u8 regs[RV3029_WATCH_SECTION_LEN] = { 0, };
ret = regmap_read(rv3029->regmap, RV3029_STATUS, &sr);
if (ret < 0)
return ret;
if (sr & (RV3029_STATUS_VLOW2 | RV3029_STATUS_PON))
return -EINVAL;
ret = regmap_bulk_read(rv3029->regmap, RV3029_W_SEC, regs,
RV3029_WATCH_SECTION_LEN);
if (ret < 0) {
@ -454,9 +463,9 @@ static int rv3029_set_time(struct device *dev, struct rtc_time *tm)
if (ret < 0)
return ret;
/* clear PON bit */
/* clear PON and VLOW2 bits */
return regmap_update_bits(rv3029->regmap, RV3029_STATUS,
RV3029_STATUS_PON, 0);
RV3029_STATUS_PON | RV3029_STATUS_VLOW2, 0);
}
static int rv3029_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)