rtc: rs5c348: report error when time is invalid
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@bootlin.com>
diff --git a/drivers/rtc/rtc-rs5c348.c b/drivers/rtc/rtc-rs5c348.c
index 7b9c7dc..6582be7 100644
--- a/drivers/rtc/rtc-rs5c348.c
+++ b/drivers/rtc/rtc-rs5c348.c
@@ -66,6 +66,17 @@
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 @@
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 @@
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;