rtc: Add DM support to ds1307

Add an implementation of the ds1307 driver that uses the driver model
i2c APIs.

Signed-off-by: Chris Packham <judge.packham@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/rtc/Kconfig

@@ -23,4 +23,11 @@ config RTC_PCF2127
 	  has a selectable I2C-bus or SPI-bus, a backup battery switch-over circuit, a
 	  programmable watchdog function, a timestamp function, and many other features.
 
+config RTC_DS1307
+	bool "Enable DS1307 driver"
+	depends on DM_RTC
+	help
+	  Support for Dallas Semiconductor (now Maxim) DS1307 and DS1338/9 and
+	  compatible Real Time Clock devices.
+
 endmenu

drivers/rtc/ds1307.c

@@ -16,28 +16,16 @@
 
 #include <common.h>
 #include <command.h>
+#include <dm.h>
 #include <rtc.h>
 #include <i2c.h>
 
-#if defined(CONFIG_CMD_DATE)
-
-/*---------------------------------------------------------------------*/
-#undef DEBUG_RTC
-
-#ifdef DEBUG_RTC
-#define DEBUGR(fmt,args...) printf(fmt ,##args)
-#else
-#define DEBUGR(fmt,args...)
-#endif
-/*---------------------------------------------------------------------*/
-
-#ifndef CONFIG_SYS_I2C_RTC_ADDR
-# define CONFIG_SYS_I2C_RTC_ADDR	0x68
-#endif
-
-#if defined(CONFIG_RTC_DS1307) && (CONFIG_SYS_I2C_SPEED > 100000)
-# error The DS1307 is specified only up to 100kHz!
-#endif
+enum ds_type {
+	ds_1307,
+	ds_1337,
+	ds_1340,
+	mcp794xx,
+};
 
 /*
  * RTC register addresses
@@ -62,6 +50,28 @@
 #define MCP7941X_BIT_ST		0x80
 #define MCP7941X_BIT_VBATEN	0x08
 
+#ifndef CONFIG_DM_RTC
+
+#if defined(CONFIG_CMD_DATE)
+
+/*---------------------------------------------------------------------*/
+#undef DEBUG_RTC
+
+#ifdef DEBUG_RTC
+#define DEBUGR(fmt, args...) printf(fmt, ##args)
+#else
+#define DEBUGR(fmt, args...)
+#endif
+/*---------------------------------------------------------------------*/
+
+#ifndef CONFIG_SYS_I2C_RTC_ADDR
+# define CONFIG_SYS_I2C_RTC_ADDR	0x68
+#endif
+
+#if defined(CONFIG_RTC_DS1307) && (CONFIG_SYS_I2C_SPEED > 100000)
+# error The DS1307 is specified only up to 100kHz!
+#endif
+
 static uchar rtc_read (uchar reg);
 static void rtc_write (uchar reg, uchar val);
 
@@ -211,4 +221,163 @@ static void rtc_write (uchar reg, uchar val)
 {
 	i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
 }
-#endif
+
+#endif /* CONFIG_CMD_DATE*/
+
+#endif /* !CONFIG_DM_RTC */
+
+#ifdef CONFIG_DM_RTC
+static int ds1307_rtc_set(struct udevice *dev, const struct rtc_time *tm)
+{
+	int ret;
+	uchar buf[7];
+	enum ds_type type = dev_get_driver_data(dev);
+
+	debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
+	      tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
+	      tm->tm_hour, tm->tm_min, tm->tm_sec);
+
+	if (tm->tm_year < 1970 || tm->tm_year > 2069)
+		printf("WARNING: year should be between 1970 and 2069!\n");
+
+	buf[RTC_YR_REG_ADDR] = bin2bcd(tm->tm_year % 100);
+	buf[RTC_MON_REG_ADDR] = bin2bcd(tm->tm_mon);
+	buf[RTC_DAY_REG_ADDR] = bin2bcd(tm->tm_wday + 1);
+	buf[RTC_DATE_REG_ADDR] = bin2bcd(tm->tm_mday);
+	buf[RTC_HR_REG_ADDR] = bin2bcd(tm->tm_hour);
+	buf[RTC_MIN_REG_ADDR] = bin2bcd(tm->tm_min);
+	buf[RTC_SEC_REG_ADDR] = bin2bcd(tm->tm_sec);
+
+	if (type == mcp794xx) {
+		buf[RTC_DAY_REG_ADDR] |= MCP7941X_BIT_VBATEN;
+		buf[RTC_SEC_REG_ADDR] |= MCP7941X_BIT_ST;
+	}
+
+	ret = dm_i2c_write(dev, 0, buf, sizeof(buf));
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int ds1307_rtc_get(struct udevice *dev, struct rtc_time *tm)
+{
+	int ret;
+	uchar buf[7];
+	enum ds_type type = dev_get_driver_data(dev);
+
+read_rtc:
+	ret = dm_i2c_read(dev, 0, buf, sizeof(buf));
+	if (ret < 0)
+		return ret;
+
+	if (type == ds_1307) {
+		if (buf[RTC_SEC_REG_ADDR] & RTC_SEC_BIT_CH) {
+			printf("### Warning: RTC oscillator has stopped\n");
+			/* clear the CH flag */
+			buf[RTC_SEC_REG_ADDR] &= ~RTC_SEC_BIT_CH;
+			dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR,
+					 buf[RTC_SEC_REG_ADDR]);
+			return -1;
+		}
+	}
+
+	if (type == mcp794xx) {
+		/* make sure that the backup battery is enabled */
+		if (!(buf[RTC_DAY_REG_ADDR] & MCP7941X_BIT_VBATEN)) {
+			dm_i2c_reg_write(dev, RTC_DAY_REG_ADDR,
+					 buf[RTC_DAY_REG_ADDR] |
+					 MCP7941X_BIT_VBATEN);
+		}
+
+		/* clock halted?  turn it on, so clock can tick. */
+		if (!(buf[RTC_SEC_REG_ADDR] & MCP7941X_BIT_ST)) {
+			dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR,
+					 MCP7941X_BIT_ST);
+			printf("Started RTC\n");
+			goto read_rtc;
+		}
+	}
+
+	tm->tm_sec  = bcd2bin(buf[RTC_SEC_REG_ADDR] & 0x7F);
+	tm->tm_min  = bcd2bin(buf[RTC_MIN_REG_ADDR] & 0x7F);
+	tm->tm_hour = bcd2bin(buf[RTC_HR_REG_ADDR] & 0x3F);
+	tm->tm_mday = bcd2bin(buf[RTC_DATE_REG_ADDR] & 0x3F);
+	tm->tm_mon  = bcd2bin(buf[RTC_MON_REG_ADDR] & 0x1F);
+	tm->tm_year = bcd2bin(buf[RTC_YR_REG_ADDR]) +
+			      (bcd2bin(buf[RTC_YR_REG_ADDR]) >= 70 ?
+			       1900 : 2000);
+	tm->tm_wday = bcd2bin((buf[RTC_DAY_REG_ADDR] - 1) & 0x07);
+	tm->tm_yday = 0;
+	tm->tm_isdst = 0;
+
+	debug("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
+	      tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
+	      tm->tm_hour, tm->tm_min, tm->tm_sec);
+
+	return 0;
+}
+
+static int ds1307_rtc_reset(struct udevice *dev)
+{
+	int ret;
+	struct rtc_time tmp = {
+		.tm_year = 1970,
+		.tm_mon = 1,
+		.tm_mday = 1,
+		.tm_hour = 0,
+		.tm_min = 0,
+		.tm_sec = 0,
+	};
+
+	/* clear Clock Halt */
+	ret = dm_i2c_reg_write(dev, RTC_SEC_REG_ADDR, 0x00);
+	if (ret < 0)
+		return ret;
+	ret = dm_i2c_reg_write(dev, RTC_CTL_REG_ADDR,
+			       RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 |
+			       RTC_CTL_BIT_RS0);
+	if (ret < 0)
+		return ret;
+
+	ret = ds1307_rtc_set(dev, &tmp);
+	if (ret < 0)
+		return ret;
+
+	debug("RTC:   %4d-%02d-%02d %2d:%02d:%02d UTC\n",
+	      tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
+	      tmp.tm_hour, tmp.tm_min, tmp.tm_sec);
+
+	return 0;
+}
+
+static int ds1307_probe(struct udevice *dev)
+{
+	i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
+			   DM_I2C_CHIP_WR_ADDRESS);
+
+	return 0;
+}
+
+static const struct rtc_ops ds1307_rtc_ops = {
+	.get = ds1307_rtc_get,
+	.set = ds1307_rtc_set,
+	.reset = ds1307_rtc_reset,
+};
+
+static const struct udevice_id ds1307_rtc_ids[] = {
+	{ .compatible = "dallas,ds1307", .data = ds_1307 },
+	{ .compatible = "dallas,ds1337", .data = ds_1337 },
+	{ .compatible = "dallas,ds1340", .data = ds_1340 },
+	{ .compatible = "microchip,mcp7941x", .data = mcp794xx },
+	{ }
+};
+
+U_BOOT_DRIVER(rtc_ds1307) = {
+	.name	= "rtc-ds1307",
+	.id	= UCLASS_RTC,
+	.probe	= ds1307_probe,
+	.of_match = ds1307_rtc_ids,
+	.ops	= &ds1307_rtc_ops,
+};
+#endif /* CONFIG_DM_RTC */