From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.bootlin.com ([62.4.15.54]:43352 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733208AbeIXVIC (ORCPT ); Mon, 24 Sep 2018 17:08:02 -0400 From: Alexandre Belloni To: linux-rtc@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Alexandre Belloni Subject: [PATCH 3/3] rtc: rs5c348: report error when time is invalid Date: Mon, 24 Sep 2018 17:05:09 +0200 Message-Id: <20180924150509.2082-3-alexandre.belloni@bootlin.com> In-Reply-To: <20180924150509.2082-1-alexandre.belloni@bootlin.com> References: <20180924150509.2082-1-alexandre.belloni@bootlin.com> MIME-Version: 1.0 Sender: linux-rtc-owner@vger.kernel.org List-ID: 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 --- 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