Messages in this thread Patch in this message | | | From | Joshua Clayton <> | Subject | [PATCH 2/9] rtc-pcf2123: clean up reads from the chip | Date | Wed, 4 Nov 2015 07:36:33 -0800 |
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put read operations into a function. This makes the starting register more prominent and hides the delay.
Signed-off-by: Joshua Clayton <stillcompiling@gmail.com> --- drivers/rtc/rtc-pcf2123.c | 39 ++++++++++++++++++++++----------------- 1 file changed, 22 insertions(+), 17 deletions(-)
diff --git a/drivers/rtc/rtc-pcf2123.c b/drivers/rtc/rtc-pcf2123.c index 7756210..648cb74 100644 --- a/drivers/rtc/rtc-pcf2123.c +++ b/drivers/rtc/rtc-pcf2123.c @@ -104,12 +104,26 @@ static inline void pcf2123_delay_trec(void) ndelay(30); } +static int pcf2123_read(struct device *dev, u8 reg, u8 *rxbuf, size_t size) +{ + struct spi_device *spi = to_spi_device(dev); + int ret; + + if (reg > PCF2123_REG_MAX) + return -EFAULT; + + reg |= PCF2123_READ; + ret = spi_write_then_read(spi, ®, 1, rxbuf, size); + pcf2123_delay_trec(); + + return ret; +} + static ssize_t pcf2123_show(struct device *dev, struct device_attribute *attr, char *buffer) { - struct spi_device *spi = to_spi_device(dev); struct pcf2123_sysfs_reg *r; - u8 txbuf[1], rxbuf[1]; + u8 rxbuf[1]; unsigned long reg; int ret; @@ -119,11 +133,10 @@ static ssize_t pcf2123_show(struct device *dev, struct device_attribute *attr, if (ret) return ret; - txbuf[0] = PCF2123_READ | reg; - ret = spi_write_then_read(spi, txbuf, 1, rxbuf, 1); + ret = pcf2123_read(dev, reg, rxbuf, 1); if (ret < 0) return -EIO; - pcf2123_delay_trec(); + return sprintf(buffer, "0x%x\n", rxbuf[0]); } @@ -158,16 +171,12 @@ static ssize_t pcf2123_store(struct device *dev, struct device_attribute *attr, static int pcf2123_rtc_read_time(struct device *dev, struct rtc_time *tm) { - struct spi_device *spi = to_spi_device(dev); - u8 txbuf[1], rxbuf[7]; + u8 rxbuf[7]; int ret; - txbuf[0] = PCF2123_READ | PCF2123_REG_SC; - ret = spi_write_then_read(spi, txbuf, sizeof(txbuf), - rxbuf, sizeof(rxbuf)); + ret = pcf2123_read(dev, PCF2123_REG_SC, rxbuf, sizeof(rxbuf)); if (ret < 0) return ret; - pcf2123_delay_trec(); tm->tm_sec = bcd2bin(rxbuf[0] & 0x7F); tm->tm_min = bcd2bin(rxbuf[1] & 0x7F); @@ -279,16 +288,12 @@ static int pcf2123_probe(struct spi_device *spi) pcf2123_delay_trec(); /* See if the counter was actually stopped */ - txbuf[0] = PCF2123_READ | PCF2123_REG_CTRL1; - dev_dbg(&spi->dev, "checking for presence of RTC (0x%02X)\n", - txbuf[0]); - ret = spi_write_then_read(spi, txbuf, 1 * sizeof(u8), - rxbuf, 2 * sizeof(u8)); + dev_dbg(&spi->dev, "checking for presence of RTC\n"); + ret = pcf2123_read(&spi->dev, PCF2123_REG_CTRL1, rxbuf, sizeof(rxbuf)); dev_dbg(&spi->dev, "received data from RTC (0x%02X 0x%02X)\n", rxbuf[0], rxbuf[1]); if (ret < 0) goto kfree_exit; - pcf2123_delay_trec(); if (!(rxbuf[0] & 0x20)) { dev_err(&spi->dev, "chip not found\n"); -- 2.5.0
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