lkml.org 
[lkml]   [2019]   [Dec]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 08/17] rtc: pcf8563: stop caching voltage_low
Date
voltage_low is only updated when reading the time, this means that using
RTC_VL_READ will miss the VL flag if the time has not been read before
using the ioctl. Always read the status from the hardware.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
drivers/rtc/rtc-pcf8563.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/rtc/rtc-pcf8563.c b/drivers/rtc/rtc-pcf8563.c
index 026192fc0c2a..7fc43950cf6c 100644
--- a/drivers/rtc/rtc-pcf8563.c
+++ b/drivers/rtc/rtc-pcf8563.c
@@ -76,7 +76,6 @@ struct pcf8563 {
* 1970...2069.
*/
int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
- int voltage_low; /* incicates if a low_voltage was detected */

struct i2c_client *client;
#ifdef CONFIG_COMMON_CLK
@@ -208,7 +207,6 @@ static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
return err;

if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
- pcf8563->voltage_low = 1;
dev_err(&client->dev,
"low voltage detected, date/time is not reliable.\n");
return -EINVAL;
@@ -278,15 +276,19 @@ static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)

static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
- struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev));
+ struct i2c_client *client = to_i2c_client(dev);
+ int vl, ret;

switch (cmd) {
case RTC_VL_READ:
- if (pcf8563->voltage_low)
- dev_info(dev, "low voltage detected, date/time is not reliable.\n");

- if (copy_to_user((void __user *)arg, &pcf8563->voltage_low,
- sizeof(int)))
+ ret = i2c_smbus_read_byte_data(client, PCF8563_REG_SC);
+ if (ret < 0)
+ return ret;
+
+ vl = ret & PCF8563_SC_LV ? 1 : 0;
+
+ if (copy_to_user((void __user *)arg, &vl, sizeof(int)))
return -EFAULT;
return 0;
default:
--
2.23.0
\
 
 \ /
  Last update: 2019-12-14 23:04    [W:0.053 / U:4.724 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site