[PATCH v3 02/14] rtc: pcf2127: adapt for time/date registers at any offset

From: Hugo Villeneuve
Date: Thu Dec 15 2022 - 10:20:05 EST


From: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>

This will simplify the implementation of new variants into this driver.

Some variants (PCF2131) have a 100th seconds register. This register is
currently not supported in this driver.

Signed-off-by: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
---
drivers/rtc/rtc-pcf2127.c | 68 ++++++++++++++++++++++-----------------
1 file changed, 39 insertions(+), 29 deletions(-)

diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
index b9a5d47a439f..fb0caacaabee 100644
--- a/drivers/rtc/rtc-pcf2127.c
+++ b/drivers/rtc/rtc-pcf2127.c
@@ -44,14 +44,17 @@
#define PCF2127_BIT_CTRL3_BF BIT(3)
#define PCF2127_BIT_CTRL3_BTSE BIT(4)
/* Time and date registers */
-#define PCF2127_REG_SC 0x03
+#define PCF2127_REG_TIME_DATE_BASE 0x03
+/* Time and date registers offsets (starting from base register) */
+#define PCF2127_OFFSET_TD_SC 0
+#define PCF2127_OFFSET_TD_MN 1
+#define PCF2127_OFFSET_TD_HR 2
+#define PCF2127_OFFSET_TD_DM 3
+#define PCF2127_OFFSET_TD_DW 4
+#define PCF2127_OFFSET_TD_MO 5
+#define PCF2127_OFFSET_TD_YR 6
+/* Time and date registers bits */
#define PCF2127_BIT_SC_OSF BIT(7)
-#define PCF2127_REG_MN 0x04
-#define PCF2127_REG_HR 0x05
-#define PCF2127_REG_DM 0x06
-#define PCF2127_REG_DW 0x07
-#define PCF2127_REG_MO 0x08
-#define PCF2127_REG_YR 0x09
/* Alarm registers */
#define PCF2127_REG_ALARM_SC 0x0A
#define PCF2127_REG_ALARM_MN 0x0B
@@ -106,6 +109,7 @@ struct pcf21xx_config {
int max_register;
unsigned int has_nvmem:1;
unsigned int has_bit_wd_ctl_cd0:1;
+ u8 regs_td_base; /* Time/data base registers. */
};

struct pcf2127 {
@@ -125,27 +129,31 @@ struct pcf2127 {
static int pcf2127_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
- unsigned char buf[10];
+ unsigned char buf[7];
+ unsigned int ctrl3;
int ret;

/*
* Avoid reading CTRL2 register as it causes WD_VAL register
* value to reset to 0 which means watchdog is stopped.
*/
- ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_CTRL3,
- (buf + PCF2127_REG_CTRL3),
- ARRAY_SIZE(buf) - PCF2127_REG_CTRL3);
- if (ret) {
- dev_err(dev, "%s: read error\n", __func__);
+ ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL3, &ctrl3);
+ if (ret)
return ret;
- }

- if (buf[PCF2127_REG_CTRL3] & PCF2127_BIT_CTRL3_BLF)
+ if (ctrl3 & PCF2127_BIT_CTRL3_BLF)
dev_info(dev,
"low voltage detected, check/replace RTC battery.\n");

+ ret = regmap_bulk_read(pcf2127->regmap, pcf2127->cfg->regs_td_base,
+ buf, sizeof(buf));
+ if (ret) {
+ dev_err(dev, "%s: read error\n", __func__);
+ return ret;
+ }
+
/* Clock integrity is not guaranteed when OSF flag is set. */
- if (buf[PCF2127_REG_SC] & PCF2127_BIT_SC_OSF) {
+ if (buf[PCF2127_OFFSET_TD_SC] & PCF2127_BIT_SC_OSF) {
/*
* no need clear the flag here,
* it will be cleared once the new date is saved
@@ -158,18 +166,18 @@ static int pcf2127_rtc_read_time(struct device *dev, struct rtc_time *tm)
dev_dbg(dev,
"%s: raw data is cr3=%02x, sec=%02x, min=%02x, hr=%02x, "
"mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
- __func__, buf[PCF2127_REG_CTRL3], buf[PCF2127_REG_SC],
- buf[PCF2127_REG_MN], buf[PCF2127_REG_HR],
- buf[PCF2127_REG_DM], buf[PCF2127_REG_DW],
- buf[PCF2127_REG_MO], buf[PCF2127_REG_YR]);
-
- tm->tm_sec = bcd2bin(buf[PCF2127_REG_SC] & 0x7F);
- tm->tm_min = bcd2bin(buf[PCF2127_REG_MN] & 0x7F);
- tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F); /* rtc hr 0-23 */
- tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F);
- tm->tm_wday = buf[PCF2127_REG_DW] & 0x07;
- tm->tm_mon = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
- tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]);
+ __func__, ctrl3, buf[PCF2127_OFFSET_TD_SC],
+ buf[PCF2127_OFFSET_TD_MN], buf[PCF2127_OFFSET_TD_HR],
+ buf[PCF2127_OFFSET_TD_DM], buf[PCF2127_OFFSET_TD_DW],
+ buf[PCF2127_OFFSET_TD_MO], buf[PCF2127_OFFSET_TD_YR]);
+
+ tm->tm_sec = bcd2bin(buf[PCF2127_OFFSET_TD_SC] & 0x7F);
+ tm->tm_min = bcd2bin(buf[PCF2127_OFFSET_TD_MN] & 0x7F);
+ tm->tm_hour = bcd2bin(buf[PCF2127_OFFSET_TD_HR] & 0x3F); /* rtc hr 0-23 */
+ tm->tm_mday = bcd2bin(buf[PCF2127_OFFSET_TD_DM] & 0x3F);
+ tm->tm_wday = buf[PCF2127_OFFSET_TD_DW] & 0x07;
+ tm->tm_mon = bcd2bin(buf[PCF2127_OFFSET_TD_MO] & 0x1F) - 1; /* rtc mn 1-12 */
+ tm->tm_year = bcd2bin(buf[PCF2127_OFFSET_TD_YR]);
tm->tm_year += 100;

dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
@@ -207,7 +215,7 @@ static int pcf2127_rtc_set_time(struct device *dev, struct rtc_time *tm)
buf[i++] = bin2bcd(tm->tm_year - 100);

/* write register's data */
- err = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_SC, buf, i);
+ err = regmap_bulk_write(pcf2127->regmap, pcf2127->cfg->regs_td_base, buf, i);
if (err) {
dev_err(dev,
"%s: err=%d", __func__, err);
@@ -650,11 +658,13 @@ static struct pcf21xx_config pcf21xx_cfg[] = {
.max_register = 0x1d,
.has_nvmem = 1,
.has_bit_wd_ctl_cd0 = 1,
+ .regs_td_base = PCF2127_REG_TIME_DATE_BASE,
},
[PCF2129] = {
.max_register = 0x19,
.has_nvmem = 0,
.has_bit_wd_ctl_cd0 = 0,
+ .regs_td_base = PCF2127_REG_TIME_DATE_BASE,
},
};

--
2.30.2