[PATCH v2 3/8] rtc-pcf2123: clean up writes to the rtc chip

From: Joshua Clayton
Date: Mon Jan 04 2016 - 13:33:46 EST


Add new functions pcf2123_write(), and pcf2123_write_reg().
Use named defines for the values being written.

This improves modularity and readability, and reduces lines of code.

Signed-off-by: Joshua Clayton <stillcompiling@xxxxxxxxx>
---
drivers/rtc/rtc-pcf2123.c | 67 ++++++++++++++++++++++-------------------------
1 file changed, 32 insertions(+), 35 deletions(-)

diff --git a/drivers/rtc/rtc-pcf2123.c b/drivers/rtc/rtc-pcf2123.c
index 4c4b3fc..0f2ce45 100644
--- a/drivers/rtc/rtc-pcf2123.c
+++ b/drivers/rtc/rtc-pcf2123.c
@@ -140,6 +140,27 @@ static int pcf2123_read(struct device *dev, u8 reg, u8 *rxbuf, size_t size)
return ret;
}

+static int pcf2123_write(struct device *dev, u8 *txbuf, size_t size)
+{
+ struct spi_device *spi = to_spi_device(dev);
+ int ret;
+
+ txbuf[0] |= PCF2123_WRITE;
+ ret = spi_write(spi, txbuf, size);
+ pcf2123_delay_trec();
+
+ return ret;
+}
+
+static int pcf2123_write_reg(struct device *dev, u8 reg, u8 val)
+{
+ u8 txbuf[2];
+
+ txbuf[0] = reg;
+ txbuf[1] = val;
+ return pcf2123_write(dev, txbuf, sizeof(txbuf));
+}
+
static ssize_t pcf2123_show(struct device *dev, struct device_attribute *attr,
char *buffer)
{
@@ -163,9 +184,7 @@ static ssize_t pcf2123_show(struct device *dev, struct device_attribute *attr,

static ssize_t pcf2123_store(struct device *dev, struct device_attribute *attr,
const char *buffer, size_t count) {
- struct spi_device *spi = to_spi_device(dev);
struct pcf2123_sysfs_reg *r;
- u8 txbuf[2];
unsigned long reg;
unsigned long val;

@@ -181,12 +200,9 @@ static ssize_t pcf2123_store(struct device *dev, struct device_attribute *attr,
if (ret)
return ret;

- txbuf[0] = PCF2123_WRITE | reg;
- txbuf[1] = val;
- ret = spi_write(spi, txbuf, sizeof(txbuf));
+ pcf2123_write_reg(dev, reg, val);
if (ret < 0)
return -EIO;
- pcf2123_delay_trec();
return count;
}

@@ -220,7 +236,6 @@ static int pcf2123_rtc_read_time(struct device *dev, struct rtc_time *tm)

static int pcf2123_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
- struct spi_device *spi = to_spi_device(dev);
u8 txbuf[8];
int ret;

@@ -231,15 +246,12 @@ static int pcf2123_rtc_set_time(struct device *dev, struct rtc_time *tm)
tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

/* Stop the counter first */
- txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
- txbuf[1] = 0x20;
- ret = spi_write(spi, txbuf, 2);
+ ret = pcf2123_write_reg(dev, PCF2123_REG_CTRL1, CTRL1_STOP);
if (ret < 0)
return ret;
- pcf2123_delay_trec();

/* Set the new time */
- txbuf[0] = PCF2123_WRITE | PCF2123_REG_SC;
+ txbuf[0] = PCF2123_REG_SC;
txbuf[1] = bin2bcd(tm->tm_sec & 0x7F);
txbuf[2] = bin2bcd(tm->tm_min & 0x7F);
txbuf[3] = bin2bcd(tm->tm_hour & 0x3F);
@@ -248,18 +260,14 @@ static int pcf2123_rtc_set_time(struct device *dev, struct rtc_time *tm)
txbuf[6] = bin2bcd((tm->tm_mon + 1) & 0x1F); /* rtc mn 1-12 */
txbuf[7] = bin2bcd(tm->tm_year < 100 ? tm->tm_year : tm->tm_year - 100);

- ret = spi_write(spi, txbuf, sizeof(txbuf));
+ ret = pcf2123_write(dev, txbuf, sizeof(txbuf));
if (ret < 0)
return ret;
- pcf2123_delay_trec();

/* Start the counter */
- txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
- txbuf[1] = 0x00;
- ret = spi_write(spi, txbuf, 2);
+ ret = pcf2123_write_reg(dev, PCF2123_REG_CTRL1, CTRL1_CLEAR);
if (ret < 0)
return ret;
- pcf2123_delay_trec();

return 0;
}
@@ -273,7 +281,7 @@ static int pcf2123_probe(struct spi_device *spi)
{
struct rtc_device *rtc;
struct pcf2123_plat_data *pdata;
- u8 txbuf[2], rxbuf[2];
+ u8 rxbuf[2];
int ret, i;

pdata = devm_kzalloc(&spi->dev, sizeof(struct pcf2123_plat_data),
@@ -283,24 +291,16 @@ static int pcf2123_probe(struct spi_device *spi)
spi->dev.platform_data = pdata;

/* Send a software reset command */
- txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
- txbuf[1] = 0x58;
- dev_dbg(&spi->dev, "resetting RTC (0x%02X 0x%02X)\n",
- txbuf[0], txbuf[1]);
- ret = spi_write(spi, txbuf, 2 * sizeof(u8));
+ dev_dbg(&spi->dev, "resetting RTC\n");
+ ret = pcf2123_write_reg(&spi->dev, PCF2123_REG_CTRL1, CTRL1_SW_RESET);
if (ret < 0)
goto kfree_exit;
- pcf2123_delay_trec();

/* Stop the counter */
- txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
- txbuf[1] = 0x20;
- dev_dbg(&spi->dev, "stopping RTC (0x%02X 0x%02X)\n",
- txbuf[0], txbuf[1]);
- ret = spi_write(spi, txbuf, 2 * sizeof(u8));
+ dev_dbg(&spi->dev, "stopping RTC\n");
+ ret = pcf2123_write_reg(&spi->dev, PCF2123_REG_CTRL1, CTRL1_STOP);
if (ret < 0)
goto kfree_exit;
- pcf2123_delay_trec();

/* See if the counter was actually stopped */
dev_dbg(&spi->dev, "checking for presence of RTC\n");
@@ -321,12 +321,9 @@ static int pcf2123_probe(struct spi_device *spi)
(spi->max_speed_hz + 500) / 1000);

/* Start the counter */
- txbuf[0] = PCF2123_WRITE | PCF2123_REG_CTRL1;
- txbuf[1] = 0x00;
- ret = spi_write(spi, txbuf, sizeof(txbuf));
+ ret = pcf2123_write_reg(&spi->dev, PCF2123_REG_CTRL1, CTRL1_CLEAR);
if (ret < 0)
goto kfree_exit;
- pcf2123_delay_trec();

/* Finalize the initialization */
rtc = devm_rtc_device_register(&spi->dev, pcf2123_driver.driver.name,
--
2.5.0

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