Instead of resetting the RTC to an bogus valid time, let userspace know
that the time is invalid when XSTP is set. Reset XSTP when setting the time
again.
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
---
drivers/rtc/rtc-rs5c348.c | 43 +++++++++++++++++++--------------------
1 file changed, 21 insertions(+), 22 deletions(-)
diff --git a/drivers/rtc/rtc-rs5c348.c b/drivers/rtc/rtc-rs5c348.c
index 7b9c7dc5b309..6582be707bd0 100644
--- a/drivers/rtc/rtc-rs5c348.c
+++ b/drivers/rtc/rtc-rs5c348.c
@@ -66,6 +66,17 @@ rs5c348_rtc_set_time(struct device *dev, struct rtc_time *tm)
u8 txbuf[5+7], *txp;
int ret;
+ ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_CTL2));
+ if (ret < 0)
+ return ret;
+ if (ret & RS5C348_BIT_XSTP) {
+ txbuf[0] = RS5C348_CMD_W(RS5C348_REG_CTL2);
+ txbuf[1] = 0;
+ ret = spi_write_then_read(spi, txbuf, 2, NULL, 0);
+ if (ret < 0)
+ return ret;
+ }
+
/* Transfer 5 bytes before writing SEC. This gives 31us for carry. */
txp = txbuf;
txbuf[0] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
@@ -102,6 +113,16 @@ rs5c348_rtc_read_time(struct device *dev, struct rtc_time *tm)
u8 txbuf[5], rxbuf[7];
int ret;
+ ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_CTL2));
+ if (ret < 0)
+ return ret;
+ if (ret & RS5C348_BIT_VDET)
+ dev_warn(&spi->dev, "voltage-low detected.\n");
+ if (ret & RS5C348_BIT_XSTP) {
+ dev_warn(&spi->dev, "oscillator-stop detected.\n");
+ return -EINVAL;
+ }
+
/* Transfer 5 byte befores reading SEC. This gives 31us for carry. */
txbuf[0] = RS5C348_CMD_R(RS5C348_REG_CTL2); /* cmd, ctl2 */
txbuf[1] = 0; /* dummy */
@@ -165,28 +186,6 @@ static int rs5c348_probe(struct spi_device *spi)
dev_info(&spi->dev, "spiclk %u KHz.\n",
(spi->max_speed_hz + 500) / 1000);
- /* turn RTC on if it was not on */
- ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_CTL2));
- if (ret < 0)
- return ret;
- if (ret & (RS5C348_BIT_XSTP | RS5C348_BIT_VDET)) {
- u8 buf[2];
- struct rtc_time tm;
- if (ret & RS5C348_BIT_VDET)
- dev_warn(&spi->dev, "voltage-low detected.\n");
- if (ret & RS5C348_BIT_XSTP)
- dev_warn(&spi->dev, "oscillator-stop detected.\n");
- rtc_time_to_tm(0, &tm); /* 1970/1/1 */
- ret = rs5c348_rtc_set_time(&spi->dev, &tm);
- if (ret < 0)
- return ret;
- buf[0] = RS5C348_CMD_W(RS5C348_REG_CTL2);
- buf[1] = 0;
- ret = spi_write_then_read(spi, buf, sizeof(buf), NULL, 0);
- if (ret < 0)
- return ret;
- }
-
ret = spi_w8r8(spi, RS5C348_CMD_R(RS5C348_REG_CTL1));
if (ret < 0)
return ret;
--
2.19.0
