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authorDylan Howey <Dylan.Howey@tennantco.com>2019-05-03 19:52:10 +0000
committerAlexandre Belloni <alexandre.belloni@bootlin.com>2019-06-19 16:20:22 +0200
commit790d033933b8a1d6bd537bdd6c08d9af745d9b78 (patch)
treebbafe0675abef89a2cb6e952c33ea51b38f45994 /drivers/rtc/rtc-pcf2123.c
parent2372a7d32b694e39bfac54d7f4dd7c0edb02d19e (diff)
rtc: pcf2123: port to regmap
Also remove pcf2123_delay_trec. This claimed to add a 30ns delay to SPI writes, but I could not see any reference to this requirement in the datasheet. Closest thing I could find to a requirement are timings for the SPI chip enable line, which cannot be controlled by this driver (the ndelay came after the call to spi_write_then_read, which means it would sleep after CE has already gone inactive). Things seem to work fine without it. Signed-off-by: Dylan Howey <Dylan.Howey@tennantco.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'drivers/rtc/rtc-pcf2123.c')
-rw-r--r--drivers/rtc/rtc-pcf2123.c142
1 files changed, 61 insertions, 81 deletions
diff --git a/drivers/rtc/rtc-pcf2123.c b/drivers/rtc/rtc-pcf2123.c
index fb5cb81f2161..32bfed7eefd4 100644
--- a/drivers/rtc/rtc-pcf2123.c
+++ b/drivers/rtc/rtc-pcf2123.c
@@ -44,6 +44,7 @@
#include <linux/rtc.h>
#include <linux/spi/spi.h>
#include <linux/module.h>
+#include <linux/regmap.h>
/* REGISTERS */
#define PCF2123_REG_CTRL1 (0x00) /* Control Register 1 */
@@ -98,6 +99,7 @@
#define OFFSET_SIGN_BIT 6 /* 2's complement sign bit */
#define OFFSET_COARSE BIT(7) /* Coarse mode offset */
#define OFFSET_STEP (2170) /* Offset step in parts per billion */
+#define OFFSET_MASK GENMASK(6, 0) /* Offset value */
/* READ/WRITE ADDRESS BITS */
#define PCF2123_WRITE BIT(4)
@@ -108,66 +110,33 @@ static struct spi_driver pcf2123_driver;
struct pcf2123_plat_data {
struct rtc_device *rtc;
+ struct regmap *map;
};
-/*
- * Causes a 30 nanosecond delay to ensure that the PCF2123 chip select
- * is released properly after an SPI write. This function should be
- * called after EVERY read/write call over SPI.
- */
-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;
-
- reg |= PCF2123_READ;
- ret = spi_write_then_read(spi, &reg, 1, rxbuf, size);
- pcf2123_delay_trec();
-
- 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 const struct regmap_config pcf2123_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .read_flag_mask = PCF2123_READ,
+ .write_flag_mask = PCF2123_WRITE,
+ .max_register = PCF2123_REG_CTDWN_TMR,
+};
static int pcf2123_read_offset(struct device *dev, long *offset)
{
- int ret;
- s8 reg;
+ struct pcf2123_plat_data *pdata = dev_get_platdata(dev);
+ int ret, val;
+ unsigned int reg;
- ret = pcf2123_read(dev, PCF2123_REG_OFFSET, &reg, 1);
- if (ret < 0)
+ ret = regmap_read(pdata->map, PCF2123_REG_OFFSET, &reg);
+ if (ret)
return ret;
+ val = sign_extend32((reg & OFFSET_MASK), OFFSET_SIGN_BIT);
+
if (reg & OFFSET_COARSE)
- reg <<= 1; /* multiply by 2 and sign extend */
- else
- reg = sign_extend32(reg, OFFSET_SIGN_BIT);
+ val *= 2;
- *offset = ((long)reg) * OFFSET_STEP;
+ *offset = ((long)val) * OFFSET_STEP;
return 0;
}
@@ -184,6 +153,7 @@ static int pcf2123_read_offset(struct device *dev, long *offset)
*/
static int pcf2123_set_offset(struct device *dev, long offset)
{
+ struct pcf2123_plat_data *pdata = dev_get_platdata(dev);
s8 reg;
if (offset > OFFSET_STEP * 127)
@@ -203,16 +173,18 @@ static int pcf2123_set_offset(struct device *dev, long offset)
reg |= OFFSET_COARSE;
}
- return pcf2123_write_reg(dev, PCF2123_REG_OFFSET, reg);
+ return regmap_write(pdata->map, PCF2123_REG_OFFSET, (unsigned int)reg);
}
static int pcf2123_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
+ struct pcf2123_plat_data *pdata = dev_get_platdata(dev);
u8 rxbuf[7];
int ret;
- ret = pcf2123_read(dev, PCF2123_REG_SC, rxbuf, sizeof(rxbuf));
- if (ret < 0)
+ ret = regmap_bulk_read(pdata->map, PCF2123_REG_SC, rxbuf,
+ sizeof(rxbuf));
+ if (ret)
return ret;
if (rxbuf[0] & OSC_HAS_STOPPED) {
@@ -241,7 +213,8 @@ 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)
{
- u8 txbuf[8];
+ struct pcf2123_plat_data *pdata = dev_get_platdata(dev);
+ u8 txbuf[7];
int ret;
dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
@@ -251,27 +224,27 @@ 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 */
- ret = pcf2123_write_reg(dev, PCF2123_REG_CTRL1, CTRL1_STOP);
- if (ret < 0)
+ ret = regmap_write(pdata->map, PCF2123_REG_CTRL1, CTRL1_STOP);
+ if (ret)
return ret;
/* Set the new time */
- 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);
- txbuf[4] = bin2bcd(tm->tm_mday & 0x3F);
- txbuf[5] = tm->tm_wday & 0x07;
- 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 = pcf2123_write(dev, txbuf, sizeof(txbuf));
- if (ret < 0)
+ txbuf[0] = bin2bcd(tm->tm_sec & 0x7F);
+ txbuf[1] = bin2bcd(tm->tm_min & 0x7F);
+ txbuf[2] = bin2bcd(tm->tm_hour & 0x3F);
+ txbuf[3] = bin2bcd(tm->tm_mday & 0x3F);
+ txbuf[4] = tm->tm_wday & 0x07;
+ txbuf[5] = bin2bcd((tm->tm_mon + 1) & 0x1F); /* rtc mn 1-12 */
+ txbuf[6] = bin2bcd(tm->tm_year < 100 ? tm->tm_year : tm->tm_year - 100);
+
+ ret = regmap_bulk_write(pdata->map, PCF2123_REG_SC, txbuf,
+ sizeof(txbuf));
+ if (ret)
return ret;
/* Start the counter */
- ret = pcf2123_write_reg(dev, PCF2123_REG_CTRL1, CTRL1_CLEAR);
- if (ret < 0)
+ ret = regmap_write(pdata->map, PCF2123_REG_CTRL1, CTRL1_CLEAR);
+ if (ret)
return ret;
return 0;
@@ -279,33 +252,33 @@ static int pcf2123_rtc_set_time(struct device *dev, struct rtc_time *tm)
static int pcf2123_reset(struct device *dev)
{
+ struct pcf2123_plat_data *pdata = dev_get_platdata(dev);
int ret;
- u8 rxbuf[2];
+ unsigned int val = 0;
- ret = pcf2123_write_reg(dev, PCF2123_REG_CTRL1, CTRL1_SW_RESET);
- if (ret < 0)
+ ret = regmap_write(pdata->map, PCF2123_REG_CTRL1, CTRL1_SW_RESET);
+ if (ret)
return ret;
/* Stop the counter */
dev_dbg(dev, "stopping RTC\n");
- ret = pcf2123_write_reg(dev, PCF2123_REG_CTRL1, CTRL1_STOP);
- if (ret < 0)
+ ret = regmap_write(pdata->map, PCF2123_REG_CTRL1, CTRL1_STOP);
+ if (ret)
return ret;
/* See if the counter was actually stopped */
dev_dbg(dev, "checking for presence of RTC\n");
- ret = pcf2123_read(dev, PCF2123_REG_CTRL1, rxbuf, sizeof(rxbuf));
- if (ret < 0)
+ ret = regmap_read(pdata->map, PCF2123_REG_CTRL1, &val);
+ if (ret)
return ret;
- dev_dbg(dev, "received data from RTC (0x%02X 0x%02X)\n",
- rxbuf[0], rxbuf[1]);
- if (!(rxbuf[0] & CTRL1_STOP))
+ dev_dbg(dev, "received data from RTC (0x%08X)\n", val);
+ if (!(val & CTRL1_STOP))
return -ENODEV;
/* Start the counter */
- ret = pcf2123_write_reg(dev, PCF2123_REG_CTRL1, CTRL1_CLEAR);
- if (ret < 0)
+ ret = regmap_write(pdata->map, PCF2123_REG_CTRL1, CTRL1_CLEAR);
+ if (ret)
return ret;
return 0;
@@ -332,6 +305,13 @@ static int pcf2123_probe(struct spi_device *spi)
return -ENOMEM;
spi->dev.platform_data = pdata;
+ pdata->map = devm_regmap_init_spi(spi, &pcf2123_regmap_config);
+
+ if (IS_ERR(pdata->map)) {
+ dev_err(&spi->dev, "regmap init failed.\n");
+ goto kfree_exit;
+ }
+
ret = pcf2123_rtc_read_time(&spi->dev, &tm);
if (ret < 0) {
ret = pcf2123_reset(&spi->dev);