[PATCH] Microchip MCP795xx RTC driver patch
From: tollsimy
Date: Sun Oct 16 2022 - 12:29:32 EST
RTC Microchip mcp795 patch for 5.19-rc5
Here is the mcp795 patch for the 5.19-rc5 merge window.
The main modification are the following:
- fixed wrong driver naming: RTC is a Microchip
mcp795 and not Maxim mcp795
- added date/time write sequences: added date/time
write sequences accordingly to official silicon
errata document to fix silicon bugs.
- added support to date/time permanent storage:
the driver was missing some register bits in order
to enable the storage of date/time whenever the
device looses main power.
- added a check after starting oscillator in order
to be sure that it is properly working as specified
in the datasheet
- renamed OSCON bit to OSCRUN as in the datasheet
- add debug messages when setting and reading the
alarm
- removed wrong offset when retrieving the current
year from the device
The patch has been successfully tested in the latest
linux-next releases, and the original problems that I found have
all been resolved.
Signed-off-by: tollsimy <simonetollardo@xxxxxxxxx>
---
.../devicetree/bindings/rtc/maxim,mcp795.txt | 11 -
.../bindings/rtc/microchip,mcp795.txt | 11 +
drivers/rtc/rtc-mcp795.c | 359 ++++++++++++++----
3 files changed, 296 insertions(+), 85 deletions(-)
delete mode 100644 Documentation/devicetree/bindings/rtc/maxim,mcp795.txt
create mode 100644 Documentation/devicetree/bindings/rtc/microchip,mcp795.txt
diff --git a/Documentation/devicetree/bindings/rtc/maxim,mcp795.txt b/Documentation/devicetree/bindings/rtc/maxim,mcp795.txt
deleted file mode 100644
index a59fdd8c236d..000000000000
--- a/Documentation/devicetree/bindings/rtc/maxim,mcp795.txt
+++ /dev/null
@@ -1,11 +0,0 @@
-* Maxim MCP795 SPI Serial Real-Time Clock
-
-Required properties:
-- compatible: Should contain "maxim,mcp795".
-- reg: SPI address for chip
-
-Example:
- mcp795: rtc@0 {
- compatible = "maxim,mcp795";
- reg = <0>;
- };
diff --git a/Documentation/devicetree/bindings/rtc/microchip,mcp795.txt b/Documentation/devicetree/bindings/rtc/microchip,mcp795.txt
new file mode 100644
index 000000000000..854364c3a173
--- /dev/null
+++ b/Documentation/devicetree/bindings/rtc/microchip,mcp795.txt
@@ -0,0 +1,11 @@
+* Microchip MCP795 SPI Serial Real-Time Clock
+
+Required properties:
+- compatible: Should contain "microchip,mcp795".
+- reg: SPI address for chip
+
+Example:
+ mcp795: rtc@0 {
+ compatible = "microchip,mcp795";
+ reg = <0>;
+ };
diff --git a/drivers/rtc/rtc-mcp795.c b/drivers/rtc/rtc-mcp795.c
index 0d515b3df571..292a440b62dd 100644
--- a/drivers/rtc/rtc-mcp795.c
+++ b/drivers/rtc/rtc-mcp795.c
@@ -3,11 +3,15 @@
* SPI Driver for Microchip MCP795 RTC
*
* Copyright (C) Josef Gajdusek <atx@xxxxxxxx>
+ * Copyright (C) 2022 Simone Tollardo <simone.tollardo@xxxxxxxxx>
*
* based on other Linux RTC drivers
*
* Device datasheet:
- * https://ww1.microchip.com/downloads/en/DeviceDoc/22280A.pdf
+ * https://ww1.microchip.com/downloads/en/DeviceDoc/MCP7951X-MCP7952X-Battery-Backed-SPI-RTCC-20002300C.pdf
+ *
+ * Device errata:
+ * http://ww1.microchip.com/downloads/en/DeviceDoc/MCP795XX-Family-Silicon-Errata-80000680D.pdf
*/
#include <linux/module.h>
@@ -32,28 +36,148 @@
#define MCP795_UNLOCK 0x14
#define MCP795_IDWRITE 0x32
#define MCP795_IDREAD 0x33
-#define MCP795_CLRWDT 0x44
#define MCP795_CLRRAM 0x54
/* MCP795 RTCC registers, see datasheet table 4-1 */
+#define MCP795_REG_TMSECONDS 0x00 /* Tenths of ms (=centi-seconds) */
#define MCP795_REG_SECONDS 0x01
+#define MCP795_REG_MINUTES 0x02
+#define MCP795_REG_HOURS 0x03
#define MCP795_REG_DAY 0x04
+#define MCP795_REG_DATE 0x05
#define MCP795_REG_MONTH 0x06
+#define MCP795_REG_YEAR 0x07
#define MCP795_REG_CONTROL 0x08
+#define MCP795_REG_OSC_TRIM 0x09
+/* Alarm 0 */
#define MCP795_REG_ALM0_SECONDS 0x0C
+#define MCP795_REG_ALM0_MINUTES 0x0D
+#define MCP795_REG_ALM0_HOURS 0x0E
#define MCP795_REG_ALM0_DAY 0x0F
-
-#define MCP795_ST_BIT BIT(7)
-#define MCP795_24_BIT BIT(6)
-#define MCP795_LP_BIT BIT(5)
-#define MCP795_EXTOSC_BIT BIT(3)
-#define MCP795_OSCON_BIT BIT(5)
-#define MCP795_ALM0_BIT BIT(4)
-#define MCP795_ALM1_BIT BIT(5)
-#define MCP795_ALM0IF_BIT BIT(3)
-#define MCP795_ALM0C0_BIT BIT(4)
-#define MCP795_ALM0C1_BIT BIT(5)
-#define MCP795_ALM0C2_BIT BIT(6)
+#define MCP795_REG_ALM0_DATE 0x10
+#define MCP795_REG_ALM0_MONTH 0x11 /* Month only for alarm 0 */
+/* Alarm 1 */
+#define MCP795_REG_ALM1_TMSECONDS 0x12 /* Centi-seconds only for alarm 1 */
+#define MCP795_REG_ALM1_SECONDS 0x13
+#define MCP795_REG_ALM1_MINUTES 0x14
+#define MCP795_REG_ALM1_HOURS 0x15
+#define MCP795_REG_ALM1_DAY 0x16
+#define MCP795_REG_ALM1_DATE 0x17
+
+/* Power-Fail Timestamp */
+/* Power-Down Timetsamp */
+#define MCP795_REG_PWD_MINUTES 0x18
+#define MCP795_REG_PWD_HOURS 0x19
+#define MCP795_REG_PWD_DATE 0x1A
+#define MCP795_REG_PWD_MONTH 0x1B
+/* Power-Up Timestamp */
+#define MCP795_REG_PUP_MINUTES 0x1C
+#define MCP795_REG_PUP_HOURS 0x1D
+#define MCP795_REG_PUP_DATE 0x1E
+#define MCP795_REG_PUP_MONTH 0x1F
+
+/* MCP795_REG_CONTROL bits */
+
+/* MISC */
+#define MCP795_ST_BIT BIT(7) /* Status bit */
+#define MCP795_24_BIT BIT(6) /* 12/24 hour mode */
+#define MCP795_LP_BIT BIT(5) /* Leap Year */
+#define MCP795_OSCRUN_BIT BIT(5) /* Oscillator Run */
+#define MCP795_PWRFAIL_BIT BIT(4) /* Power Fail */
+#define MCP795_VBATEN_BIT BIT(3) /* VBAT Enable */
+
+/* RTCC 0x08 register bits */
+#define MCP795_SQWEN_BIT BIT(6) /* Square Wave Enable (MFP pin) */
+#define MCP795_ALM1_EN_BIT BIT(5) /* Alarm 1 Enable */
+#define MCP795_ALM0_EN_BIT BIT(4) /* Alarm 0 Enable */
+#define MCP795_EXTOSC_BIT BIT(3) /* External Oscillator */
+#define MCP795_CRSTRIM_BIT BIT(2) /* Crystal Trim */
+#define MCP795_SQWFS_BIT_H BIT(1) /* Square Wave Frequency Select H */
+#define MCP795_SQWFS_BIT_L BIT(0) /* Square Wave Frequency Select L */
+
+/* Alarms (0 and 1) */
+
+/* Centi-seconds - ALARM 1 ONLY */
+/* Alarms BCD Decimal Values of Centi-Second's Tens Digit (=deci-seconds) */
+#define MCP795_ALM1_CSEC_T_C0_BIT BIT(4)
+#define MCP795_ALM1_CSEC_T_C1_BIT BIT(5)
+#define MCP795_ALM1_CSEC_T_C2_BIT BIT(6)
+#define MCP795_ALM1_CSEC_T_C3_BIT BIT(6)
+/* Alarms BCD Decimal Values of Centi-Second's Ones Digit (=centi-seconds) */
+#define MCP795_ALM1_CSEC_O_C0_BIT BIT(0)
+#define MCP795_ALM1_CSEC_O_C1_BIT BIT(1)
+#define MCP795_ALM1_CSEC_O_C2_BIT BIT(2)
+#define MCP795_ALM1_CSEC_O_C3_BIT BIT(3)
+
+/* Seconds */
+/* Alarms BCD Decimal Values of Second's Tens Digit */
+#define MCP795_ALM_SEC_T_C0_BIT BIT(4)
+#define MCP795_ALM_SEC_T_C1_BIT BIT(5)
+#define MCP795_ALM_SEC_T_C2_BIT BIT(6)
+/* Alarms BCD Decimal Values of Second's Ones Digit */
+#define MCP795_ALM_SEC_O_C0_BIT BIT(0)
+#define MCP795_ALM_SEC_O_C1_BIT BIT(1)
+#define MCP795_ALM_SEC_O_C2_BIT BIT(2)
+#define MCP795_ALM_SEC_O_C3_BIT BIT(3)
+
+/* Minutes */
+/* Alarms BCD Decimal Values of Minute's Tens Digit */
+#define MCP795_ALM_MIN_T_C0_BIT BIT(4)
+#define MCP795_ALM_MIN_T_C1_BIT BIT(5)
+#define MCP795_ALM_MIN_T_C2_BIT BIT(6)
+/* Alarms BCD Decimal Values of Minute's Ones Digit */
+#define MCP795_ALM_MIN_O_C0_BIT BIT(0)
+#define MCP795_ALM_MIN_O_C1_BIT BIT(1)
+#define MCP795_ALM_MIN_O_C2_BIT BIT(2)
+#define MCP795_ALM_MIN_O_C3_BIT BIT(3)
+
+/* Hours */
+/* Alarms BCD Decimal Values of Hour's Tens Digit */
+#define MCP795_ALM_HOUR_T_C0_BIT BIT(4)
+/* Alarms BCD Decimal Values of Hour's Ones Digit */
+#define MCP795_ALM_HOUR_O_C0_BIT BIT(0)
+#define MCP795_ALM_HOUR_O_C1_BIT BIT(1)
+#define MCP795_ALM_HOUR_O_C2_BIT BIT(2)
+#define MCP795_ALM_HOUR_O_C3_BIT BIT(3)
+
+/* Days */
+/* Alarms Interrupt Flag */
+#define MCP795_ALM_IF_BIT BIT(3)
+/* Alarms BCD Decimal Values of Day's Ones Digit */
+#define MCP795_ALM_DAY_O_C0_BIT BIT(0)
+#define MCP795_ALM_DAY_O_C1_BIT BIT(1)
+#define MCP795_ALM_DAY_O_C2_BIT BIT(2)
+
+/* Date */
+/* Alarms BCD Decimal Values of Date's Tens Digit */
+#define MCP795_ALM_DATE_T_C0_BIT BIT(4)
+#define MCP795_ALM_DATE_T_C1_BIT BIT(5)
+/* Alarms BCD Decimal Values of Date's Ones Digit */
+#define MCP795_ALM_DATE_O_C0_BIT BIT(0)
+#define MCP795_ALM_DATE_O_C1_BIT BIT(1)
+#define MCP795_ALM_DATE_O_C2_BIT BIT(2)
+#define MCP795_ALM_DATE_O_C3_BIT BIT(3)
+
+/* Months */
+/* Alarms BCD Decimal Values of Month's Tens Digit */
+#define MCP795_ALM0_MONTH_T_C0_BIT BIT(3)
+/* Alarms BCD Decimal Values of Month's Ones Digit */
+#define MCP795_ALM0_MONTH_O_C0_BIT BIT(0)
+#define MCP795_ALM0_MONTH_O_C1_BIT BIT(1)
+#define MCP795_ALM0_MONTH_O_C2_BIT BIT(2)
+#define MCP795_ALM0_MONTH_O_C3_BIT BIT(3)
+
+/* Alarms Masks */
+#define MCP795_ALM_MASKS_BIT BIT(4)
+
+/* BCD mask values for alarm matching - need BCD conversion */
+#define MCP795_ALM_MASK_SEC 0x00
+#define MCP795_ALM_MASK_MIN 0x01
+#define MCP795_ALM_MASK_HOUR 0x02
+#define MCP795_ALM_MASK_DAY 0x03
+#define MCP795_ALM_MASK_DATE 0x04
+#define MCP795_ALM_MASK_CSEC 0x05
+#define MCP795_ALM_MASK_ALL 0x07
#define SEC_PER_DAY (24 * 60 * 60)
@@ -69,7 +193,7 @@ static int mcp795_rtcc_read(struct device *dev, u8 addr, u8 *buf, u8 count)
if (ret)
dev_err(dev, "Failed reading %d bytes from address %x.\n",
- count, addr);
+ count, addr);
return ret;
}
@@ -88,7 +212,7 @@ static int mcp795_rtcc_write(struct device *dev, u8 addr, u8 *data, u8 count)
if (ret)
dev_err(dev, "Failed to write %d bytes to address %x.\n",
- count, addr);
+ count, addr);
return ret;
}
@@ -123,17 +247,16 @@ static int mcp795_stop_oscillator(struct device *dev, bool *extosc)
if (ret)
return ret;
*extosc = !!(data & MCP795_EXTOSC_BIT);
- ret = mcp795_rtcc_set_bits(
- dev, MCP795_REG_CONTROL, MCP795_EXTOSC_BIT, 0);
+ ret = mcp795_rtcc_set_bits(dev, MCP795_REG_CONTROL, MCP795_EXTOSC_BIT, 0);
if (ret)
return ret;
- /* wait for the OSCON bit to clear */
+ /* wait for the OSCRUN bit to clear */
do {
usleep_range(700, 800);
ret = mcp795_rtcc_read(dev, MCP795_REG_DAY, &data, 1);
if (ret)
break;
- if (!(data & MCP795_OSCON_BIT))
+ if (!(data & MCP795_OSCRUN_BIT))
break;
} while (--retries);
@@ -143,17 +266,34 @@ static int mcp795_stop_oscillator(struct device *dev, bool *extosc)
static int mcp795_start_oscillator(struct device *dev, bool *extosc)
{
+ int ret;
+ int retries = 5;
+
if (extosc) {
u8 data = *extosc ? MCP795_EXTOSC_BIT : 0;
- int ret;
- ret = mcp795_rtcc_set_bits(
- dev, MCP795_REG_CONTROL, MCP795_EXTOSC_BIT, data);
+ ret = mcp795_rtcc_set_bits(dev, MCP795_REG_CONTROL, MCP795_EXTOSC_BIT, data);
if (ret)
return ret;
}
- return mcp795_rtcc_set_bits(
- dev, MCP795_REG_SECONDS, MCP795_ST_BIT, MCP795_ST_BIT);
+ ret = mcp795_rtcc_set_bits(dev, MCP795_REG_SECONDS, MCP795_ST_BIT, MCP795_ST_BIT);
+ if (ret)
+ return ret;
+
+ /* wait for the OSCRUN bit to set */
+ do {
+ u8 data = MCP795_OSCRUN_BIT;
+
+ usleep_range(700, 800);
+ ret = mcp795_rtcc_read(dev, MCP795_REG_DAY, &data, 1);
+ if (ret)
+ break;
+ if ((data & MCP795_OSCRUN_BIT))
+ break;
+
+ } while (--retries);
+
+ return !retries ? -EIO : ret;
}
/* Enable or disable Alarm 0 in RTC */
@@ -164,18 +304,24 @@ static int mcp795_update_alarm(struct device *dev, bool enable)
dev_dbg(dev, "%s alarm\n", enable ? "Enable" : "Disable");
if (enable) {
+ /* Disable Square Wave Function to enable Alarm output */
+ ret = mcp795_rtcc_set_bits(dev, MCP795_REG_CONTROL,
+ MCP795_SQWEN_BIT, 0);
/* clear ALM0IF (Alarm 0 Interrupt Flag) bit */
ret = mcp795_rtcc_set_bits(dev, MCP795_REG_ALM0_DAY,
- MCP795_ALM0IF_BIT, 0);
+ MCP795_ALM_IF_BIT, 0);
if (ret)
return ret;
/* enable alarm 0 */
ret = mcp795_rtcc_set_bits(dev, MCP795_REG_CONTROL,
- MCP795_ALM0_BIT, MCP795_ALM0_BIT);
+ MCP795_ALM0_EN_BIT, MCP795_ALM0_EN_BIT);
} else {
/* disable alarm 0 and alarm 1 */
ret = mcp795_rtcc_set_bits(dev, MCP795_REG_CONTROL,
- MCP795_ALM0_BIT | MCP795_ALM1_BIT, 0);
+ MCP795_ALM0_EN_BIT | MCP795_ALM1_EN_BIT, 0);
+ /* Disable Alarm output to let enable Square Wave Function */
+ ret = mcp795_rtcc_set_bits(dev, MCP795_REG_CONTROL,
+ MCP795_SQWEN_BIT, 0);
}
return ret;
}
@@ -183,7 +329,7 @@ static int mcp795_update_alarm(struct device *dev, bool enable)
static int mcp795_set_time(struct device *dev, struct rtc_time *tim)
{
int ret;
- u8 data[7];
+ u8 data[8];
bool extosc;
/* Stop RTC and store current value of EXTOSC bit */
@@ -192,32 +338,42 @@ static int mcp795_set_time(struct device *dev, struct rtc_time *tim)
return ret;
/* Read first, so we can leave config bits untouched */
- ret = mcp795_rtcc_read(dev, MCP795_REG_SECONDS, data, sizeof(data));
+ ret = mcp795_rtcc_read(dev, MCP795_REG_TMSECONDS, data, sizeof(data));
if (ret)
return ret;
- data[0] = (data[0] & 0x80) | bin2bcd(tim->tm_sec);
- data[1] = (data[1] & 0x80) | bin2bcd(tim->tm_min);
- data[2] = bin2bcd(tim->tm_hour);
- data[3] = (data[3] & 0xF8) | bin2bcd(tim->tm_wday + 1);
- data[4] = bin2bcd(tim->tm_mday);
- data[5] = (data[5] & MCP795_LP_BIT) | bin2bcd(tim->tm_mon + 1);
-
- if (tim->tm_year > 100)
- tim->tm_year -= 100;
-
- data[6] = bin2bcd(tim->tm_year);
-
- /* Always write the date and month using a separate Write command.
- * This is a workaround for a know silicon issue that some combinations
- * of date and month values may result in the date being reset to 1.
- */
- ret = mcp795_rtcc_write(dev, MCP795_REG_SECONDS, data, 5);
+ data[0] = 0x00; //centiseconds not implemented
+ data[1] = (data[0] & 0x80) | bin2bcd(tim->tm_sec);
+ data[2] = (data[1] & 0x80) | bin2bcd(tim->tm_min);
+ data[3] = (data[3] & 0xC0) | bin2bcd(tim->tm_hour);
+ /* Add one beacause Linux weekday is from 0 to 6 */
+ data[4] = (data[3] & 0xF8) | bin2bcd(tim->tm_wday + 1);
+ data[5] = (data[5] & 0xC0) | bin2bcd(tim->tm_mday);
+ /* Add one because Linux month is from 0 to 11 */
+ data[6] = (data[6] & 0xC0) | ((data[6] & MCP795_LP_BIT)
+ | bin2bcd(tim->tm_mon + 1));
+ data[7] = bin2bcd(tim->tm_year);
+
+ /* Set time sequence needed to avoid common device problems, see errata */
+ /* Write month */
+ ret = mcp795_rtcc_write(dev, MCP795_REG_MONTH, &data[6], 1);
if (ret)
return ret;
-
- ret = mcp795_rtcc_write(dev, MCP795_REG_MONTH, &data[5], 2);
+ /* Write data (month day) */
+ ret = mcp795_rtcc_write(dev, MCP795_REG_DATE, &data[5], 1);
+ if (ret)
+ return ret;
+ /* Write month again */
+ ret = mcp795_rtcc_write(dev, MCP795_REG_MONTH, &data[6], 1);
+ if (ret)
+ return ret;
+ /* Send the rest apart from year and dayweek */
+ ret = mcp795_rtcc_write(dev, MCP795_REG_TMSECONDS, data, 4);
+ if (ret)
+ return ret;
+ /* Send the year */
+ ret = mcp795_rtcc_write(dev, MCP795_REG_YEAR, &data[7], 1);
if (ret)
return ret;
@@ -229,6 +385,14 @@ static int mcp795_set_time(struct device *dev, struct rtc_time *tim)
if (ret)
return ret;
+ /* Always set the weekday using a separate Write command and when
+ * oscillator is running.
+ * This is a workaround for a know silicon issue.
+ */
+ ret = mcp795_rtcc_write(dev, MCP795_REG_DAY, &data[4], 1);
+ if (ret)
+ return ret;
+
dev_dbg(dev, "Set mcp795: %ptR\n", tim);
return 0;
@@ -237,20 +401,23 @@ static int mcp795_set_time(struct device *dev, struct rtc_time *tim)
static int mcp795_read_time(struct device *dev, struct rtc_time *tim)
{
int ret;
- u8 data[7];
+ u8 data[8];
+ int tm_c_sec;
- ret = mcp795_rtcc_read(dev, MCP795_REG_SECONDS, data, sizeof(data));
+ ret = mcp795_rtcc_read(dev, MCP795_REG_TMSECONDS, data, sizeof(data));
if (ret)
return ret;
- tim->tm_sec = bcd2bin(data[0] & 0x7F);
- tim->tm_min = bcd2bin(data[1] & 0x7F);
- tim->tm_hour = bcd2bin(data[2] & 0x3F);
- tim->tm_wday = bcd2bin(data[3] & 0x07) - 1;
- tim->tm_mday = bcd2bin(data[4] & 0x3F);
- tim->tm_mon = bcd2bin(data[5] & 0x1F) - 1;
- tim->tm_year = bcd2bin(data[6]) + 100; /* Assume we are in 20xx */
+ tm_c_sec = bcd2bin(data[0] & 0xFF);
+ tim->tm_sec = bcd2bin(data[1] & 0x7F);
+ tim->tm_min = bcd2bin(data[2] & 0x7F);
+ /* This is only for 24h mode, see datasheet for 12h mode */
+ tim->tm_hour = bcd2bin(data[3] & 0x3F);
+ tim->tm_wday = bcd2bin(data[4] & 0x07) - 1;
+ tim->tm_mday = bcd2bin(data[5] & 0x3F);
+ tim->tm_mon = bcd2bin(data[6] & 0x1F) - 1;
+ tim->tm_year = bcd2bin(data[7]);
dev_dbg(dev, "Read from mcp795: %ptR\n", tim);
@@ -265,6 +432,17 @@ static int mcp795_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
u8 tmp[6];
int ret;
+ /* Set Alarm 0 Mask to match all */
+ /* Read first, so we can leave other bits untouched */
+ ret = mcp795_rtcc_read(dev, MCP795_REG_ALM0_DAY, tmp, 1);
+ if (ret)
+ return ret;
+ /* Set Alarm 0 Mask to match all */
+ tmp[0] = (tmp[0] & 0x8F) | (bin2bcd(MCP795_ALM_MASK_ALL) << 4);
+ ret = mcp795_rtcc_write(dev, MCP795_REG_ALM0_DAY, tmp, 1);
+ if (ret)
+ return ret;
+
/* Read current time from RTC hardware */
ret = mcp795_read_time(dev, &now_tm);
if (ret)
@@ -291,12 +469,14 @@ static int mcp795_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
alm->time.tm_isdst = -1;
alm->time.tm_yday = -1;
+ /* set alarm match: seconds, minutes, hour, day, date and month */
tmp[0] = (tmp[0] & 0x80) | bin2bcd(alm->time.tm_sec);
tmp[1] = (tmp[1] & 0x80) | bin2bcd(alm->time.tm_min);
tmp[2] = (tmp[2] & 0xE0) | bin2bcd(alm->time.tm_hour);
tmp[3] = (tmp[3] & 0x80) | bin2bcd(alm->time.tm_wday + 1);
- /* set alarm match: seconds, minutes, hour, day, date and month */
- tmp[3] |= (MCP795_ALM0C2_BIT | MCP795_ALM0C1_BIT | MCP795_ALM0C0_BIT);
+ /* ALMxIF cleared in the update function */
+ tmp[3] |= (MCP795_ALM_SEC_T_C2_BIT | MCP795_ALM_SEC_T_C1_BIT
+ | MCP795_ALM_SEC_T_C0_BIT);
tmp[4] = (tmp[4] & 0xC0) | bin2bcd(alm->time.tm_mday);
tmp[5] = (tmp[5] & 0xE0) | bin2bcd(alm->time.tm_mon + 1);
@@ -309,10 +489,14 @@ static int mcp795_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
ret = mcp795_update_alarm(dev, true);
if (ret)
return ret;
+ alm->pending = 1;
dev_dbg(dev, "Alarm IRQ armed\n");
}
- dev_dbg(dev, "Set alarm: %ptRdr(%d) %ptRt\n",
- &alm->time, alm->time.tm_wday, &alm->time);
+
+ /* do not print year, it's not implemented in the RTC hardware */
+ dev_dbg(dev, "Set alarm: %02d-%02dT%02d:%02d:%02d\n", alm->time.tm_mon + 1,
+ alm->time.tm_mday, alm->time.tm_hour, alm->time.tm_min, alm->time.tm_sec);
+
return 0;
}
@@ -321,8 +505,7 @@ static int mcp795_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
u8 data[6];
int ret;
- ret = mcp795_rtcc_read(
- dev, MCP795_REG_ALM0_SECONDS, data, sizeof(data));
+ ret = mcp795_rtcc_read(dev, MCP795_REG_ALM0_SECONDS, data, sizeof(data));
if (ret)
return ret;
@@ -336,8 +519,17 @@ static int mcp795_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
alm->time.tm_isdst = -1;
alm->time.tm_yday = -1;
- dev_dbg(dev, "Read alarm: %ptRdr(%d) %ptRt\n",
- &alm->time, alm->time.tm_wday, &alm->time);
+ alm->pending = !!(data[3] & MCP795_ALM_IF_BIT);
+
+ ret = mcp795_rtcc_read(dev, MCP795_REG_CONTROL, data, 1);
+ if (ret)
+ return ret;
+ alm->enabled = !!(data[0] & MCP795_ALM0_EN_BIT);
+
+ /* Do not print year, it's not implemented in the RTC hardware */
+ dev_dbg(dev, "Read alarm: %02d-%02dT%02d:%02d:%02d\n", alm->time.tm_mon + 1,
+ alm->time.tm_mday, alm->time.tm_hour, alm->time.tm_min, alm->time.tm_sec);
+
return 0;
}
@@ -381,6 +573,7 @@ static int mcp795_probe(struct spi_device *spi)
{
struct rtc_device *rtc;
int ret;
+ u8 data;
spi->mode = SPI_MODE_0;
spi->bits_per_word = 8;
@@ -393,10 +586,10 @@ static int mcp795_probe(struct spi_device *spi)
/* Start the oscillator but don't set the value of EXTOSC bit */
mcp795_start_oscillator(&spi->dev, NULL);
/* Clear the 12 hour mode flag*/
- mcp795_rtcc_set_bits(&spi->dev, 0x03, MCP795_24_BIT, 0);
+ mcp795_rtcc_set_bits(&spi->dev, MCP795_REG_HOURS, MCP795_24_BIT, 0);
rtc = devm_rtc_device_register(&spi->dev, "rtc-mcp795",
- &mcp795_rtc_ops, THIS_MODULE);
+ &mcp795_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc))
return PTR_ERR(rtc);
@@ -409,22 +602,40 @@ static int mcp795_probe(struct spi_device *spi)
* the interrupt.
*/
mcp795_rtcc_set_bits(&spi->dev, MCP795_REG_ALM0_DAY,
- MCP795_ALM0IF_BIT, 0);
- ret = devm_request_threaded_irq(&spi->dev, spi->irq, NULL,
- mcp795_irq, IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
- dev_name(&rtc->dev), spi);
+ MCP795_ALM_IF_BIT, 0);
+ ret = devm_request_threaded_irq(&spi->dev, spi->irq, NULL, mcp795_irq,
+ IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+ dev_name(&rtc->dev), spi);
if (ret)
dev_err(&spi->dev, "Failed to request IRQ: %d: %d\n",
- spi->irq, ret);
+ spi->irq, ret);
else
device_init_wakeup(&spi->dev, true);
}
+
+ /* If PWRFAIL BIT is set, it must be cleared */
+ ret = mcp795_rtcc_read(&spi->dev, MCP795_REG_DAY, &data, 1);
+ if (ret)
+ return ret;
+
+ if (!!(data & MCP795_PWRFAIL_BIT)) {
+ ret = mcp795_rtcc_set_bits(&spi->dev, MCP795_REG_DAY,
+ MCP795_PWRFAIL_BIT, 0);
+ if (ret)
+ return ret;
+ }
+ /* Set VBAT flag to 1 */
+ ret = mcp795_rtcc_set_bits(&spi->dev, MCP795_REG_DAY, MCP795_VBATEN_BIT,
+ MCP795_VBATEN_BIT);
+ if (ret)
+ return ret;
+
return 0;
}
#ifdef CONFIG_OF
static const struct of_device_id mcp795_of_match[] = {
- { .compatible = "maxim,mcp795" },
+ { .compatible = "microchip,mcp795" },
{ }
};
MODULE_DEVICE_TABLE(of, mcp795_of_match);
--
2.37.3