From patchwork Wed Dec 19 14:04:56 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: rtc-pcf8523: Add low battery voltage support From: Jesper Nilsson X-Patchwork-Id: 207358 Message-Id: <20121219140456.GA14217@axis.com> To: Thierry Reding Cc: Andrew Morton , Alessandro Zummo , rtc-linux@googlegroups.com, linux-kernel@vger.kernel.org Date: Wed, 19 Dec 2012 15:04:56 +0100 This patch implements reading of the battery voltage low signal for rtc-pcf8523. The bit is read-only and cannot be cleared by software, so no clear-function is implemented. Signed-off-by: Jesper Nilsson --- /^JN - Jesper Nilsson diff --git a/drivers/rtc/rtc-pcf8523.c b/drivers/rtc/rtc-pcf8523.c index be05a64..82a9895 100644 --- a/drivers/rtc/rtc-pcf8523.c +++ b/drivers/rtc/rtc-pcf8523.c @@ -23,6 +23,7 @@ #define REG_CONTROL3_PM_VDD (1 << 6) /* switch-over disabled */ #define REG_CONTROL3_PM_DSM (1 << 5) /* direct switching mode */ #define REG_CONTROL3_PM_MASK 0xe0 +#define REG_CONTROL3_BLF (1 << 2) /* Battery low bit, read-only */ #define REG_SECONDS 0x03 #define REG_SECONDS_OS (1 << 7) @@ -250,9 +252,29 @@ static int pcf8523_rtc_set_time(struct device *dev, struct rtc_time *tm) return pcf8523_start_rtc(client); } +static int pcf8523_rtc_read_vl(struct device *dev, int *vl) +{ + struct i2c_client *client = to_i2c_client(dev); + u8 value; + int err; + + err = pcf8523_read(client, REG_CONTROL3, &value); + if (err < 0) + return err; + + if (value & REG_CONTROL3_BLF) + *vl = 1; + else + *vl = 0; + + return 0; +} + + static const struct rtc_class_ops pcf8523_rtc_ops = { - .read_time = pcf8523_rtc_read_time, - .set_time = pcf8523_rtc_set_time, + .read_time = pcf8523_rtc_read_time, + .set_time = pcf8523_rtc_set_time, + .read_vl = pcf8523_rtc_read_vl, }; static int pcf8523_probe(struct i2c_client *client,