[rtc-linux] [PATCH v2 3/4] rtc: ds3234: use rtc-ds3232 core and support alarm

[Akinobu Mita <akinobu.mita@gmail.com>]

Use rtc-ds3232 core module.  This change enables to
support alarm for rtc-ds3234.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Cc: Dennis Aberilla <denzzzhome@yahoo.com>
---
* no changes since v1

 drivers/rtc/Kconfig      |   1 +
 drivers/rtc/rtc-ds3234.c | 148 +++++++++++++++++++++++++----------------------
 2 files changed, 80 insertions(+), 69 deletions(-)

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index a489d89..cb27ace 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -733,6 +733,7 @@ config RTC_DRV_RS5C348
 
 config RTC_DRV_DS3234
 	tristate "Maxim/Dallas DS3234"
+	select RTC_DRV_DS3232_CORE
 	help
 	  If you say yes here you get support for the
 	  Maxim/Dallas DS3234 SPI RTC chip.
diff --git a/drivers/rtc/rtc-ds3234.c b/drivers/rtc/rtc-ds3234.c
index 570ab28..b681929 100644
--- a/drivers/rtc/rtc-ds3234.c
+++ b/drivers/rtc/rtc-ds3234.c
@@ -19,20 +19,12 @@
 #include <linux/spi/spi.h>
 #include <linux/bcd.h>
 
-#define DS3234_REG_SECONDS	0x00
-#define DS3234_REG_MINUTES	0x01
-#define DS3234_REG_HOURS	0x02
-#define DS3234_REG_DAY		0x03
-#define DS3234_REG_DATE		0x04
-#define DS3234_REG_MONTH	0x05
-#define DS3234_REG_YEAR		0x06
-#define DS3234_REG_CENTURY	(1 << 7) /* Bit 7 of the Month register */
+#include "rtc-ds3232.h"
 
 #define DS3234_REG_CONTROL	0x0E
 #define DS3234_REG_CONT_STAT	0x0F
 
-static int ds3234_set_reg(struct device *dev, unsigned char address,
-				unsigned char data)
+static int ds3234_write_byte(struct device *dev, u8 address, u8 data)
 {
 	struct spi_device *spi = to_spi_device(dev);
 	unsigned char buf[2];
@@ -44,79 +36,87 @@ static int ds3234_set_reg(struct device *dev, unsigned char address,
 	return spi_write_then_read(spi, buf, 2, NULL, 0);
 }
 
-static int ds3234_get_reg(struct device *dev, unsigned char address,
-				unsigned char *data)
+static int ds3234_read_byte(struct device *dev, u8 address)
 {
 	struct spi_device *spi = to_spi_device(dev);
+	u8 data;
+	int ret;
 
-	*data = address & 0x7f;
+	data = address & 0x7f;
 
-	return spi_write_then_read(spi, data, 1, data, 1);
+	ret = spi_write_then_read(spi, &data, 1, &data, 1);
+	if (ret)
+		return ret;
+
+	return data;
 }
 
-static int ds3234_read_time(struct device *dev, struct rtc_time *dt)
+/*
+ * SPI multiple-byte burst transfer
+ */
+static int ds3234_write_block(struct device *dev, u8 address, const void *buf,
+				int len)
 {
-	int err;
-	unsigned char buf[8];
 	struct spi_device *spi = to_spi_device(dev);
+	struct spi_message message;
+	struct spi_transfer xfer = {
+		.len = len + 1,
+	};
+	u8 *data;
+	int ret;
+
+	data = kmalloc(xfer.len, GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
 
-	buf[0] = 0x00; /* Start address */
+	data[0] = address | 0x80;
+	memcpy(data + 1, buf, len);
 
-	err = spi_write_then_read(spi, buf, 1, buf, 8);
-	if (err != 0)
-		return err;
+	xfer.tx_buf = data;
+	spi_message_init(&message);
+	spi_message_add_tail(&xfer, &message);
 
-	/* Seconds, Minutes, Hours, Day, Date, Month, Year */
-	dt->tm_sec	= bcd2bin(buf[0]);
-	dt->tm_min	= bcd2bin(buf[1]);
-	dt->tm_hour	= bcd2bin(buf[2] & 0x3f);
-	dt->tm_wday	= bcd2bin(buf[3]) - 1; /* 0 = Sun */
-	dt->tm_mday	= bcd2bin(buf[4]);
-	dt->tm_mon	= bcd2bin(buf[5] & 0x1f) - 1; /* 0 = Jan */
-	dt->tm_year	= bcd2bin(buf[6] & 0xff) + 100; /* Assume 20YY */
+	ret = spi_sync(spi, &message);
+	kfree(data);
 
-	return rtc_valid_tm(dt);
+	return ret;
 }
 
-static int ds3234_set_time(struct device *dev, struct rtc_time *dt)
+/*
+ * SPI multiple-byte burst transfer
+ */
+static int ds3234_read_block(struct device *dev, u8 addr, void *buf, int len)
 {
-	ds3234_set_reg(dev, DS3234_REG_SECONDS, bin2bcd(dt->tm_sec));
-	ds3234_set_reg(dev, DS3234_REG_MINUTES, bin2bcd(dt->tm_min));
-	ds3234_set_reg(dev, DS3234_REG_HOURS, bin2bcd(dt->tm_hour) & 0x3f);
-
-	/* 0 = Sun */
-	ds3234_set_reg(dev, DS3234_REG_DAY, bin2bcd(dt->tm_wday + 1));
-	ds3234_set_reg(dev, DS3234_REG_DATE, bin2bcd(dt->tm_mday));
-
-	/* 0 = Jan */
-	ds3234_set_reg(dev, DS3234_REG_MONTH, bin2bcd(dt->tm_mon + 1));
+	struct spi_device *spi = to_spi_device(dev);
 
-	/* Assume 20YY although we just want to make sure not to go negative. */
-	if (dt->tm_year > 100)
-		dt->tm_year -= 100;
+	return spi_write_then_read(spi, &addr, 1, buf, len);
+}
 
-	ds3234_set_reg(dev, DS3234_REG_YEAR, bin2bcd(dt->tm_year));
+static int ds3234_irq(struct device *dev)
+{
+	struct spi_device *spi = to_spi_device(dev);
 
-	return 0;
+	return spi->irq;
 }
 
-static const struct rtc_class_ops ds3234_rtc_ops = {
-	.read_time	= ds3234_read_time,
-	.set_time	= ds3234_set_time,
+static const struct ds3232_ops ds3234_ops = {
+	.read_byte = ds3234_read_byte,
+	.write_byte = ds3234_write_byte,
+	.read_block = ds3234_read_block,
+	.write_block = ds3234_write_block,
+	.irq = ds3234_irq,
 };
 
 static int ds3234_probe(struct spi_device *spi)
 {
-	struct rtc_device *rtc;
-	unsigned char tmp;
 	int res;
 
 	spi->mode = SPI_MODE_3;
 	spi->bits_per_word = 8;
 	spi_setup(spi);
 
-	res = ds3234_get_reg(&spi->dev, DS3234_REG_SECONDS, &tmp);
-	if (res != 0)
+	res = ds3234_read_byte(&spi->dev, 0);
+	if (res < 0)
 		return res;
 
 	/* Control settings
@@ -133,27 +133,37 @@ static int ds3234_probe(struct spi_device *spi)
 	 *
 	 *     1	0	0	0	1	0	0	0
 	 */
-	ds3234_get_reg(&spi->dev, DS3234_REG_CONTROL, &tmp);
-	ds3234_set_reg(&spi->dev, DS3234_REG_CONTROL, tmp & 0x1c);
+	res = ds3234_read_byte(&spi->dev, DS3234_REG_CONTROL);
+	if (res < 0)
+		return res;
+	res = ds3234_write_byte(&spi->dev, DS3234_REG_CONTROL, res & 0x1c);
+	if (res)
+		return res;
 
-	ds3234_get_reg(&spi->dev, DS3234_REG_CONT_STAT, &tmp);
-	ds3234_set_reg(&spi->dev, DS3234_REG_CONT_STAT, tmp & 0x88);
+	res = ds3234_read_byte(&spi->dev, DS3234_REG_CONT_STAT);
+	if (res < 0)
+		return res;
+	res = ds3234_write_byte(&spi->dev, DS3234_REG_CONT_STAT, res & 0x88);
+	if (res)
+		return res;
 
 	/* Print our settings */
-	ds3234_get_reg(&spi->dev, DS3234_REG_CONTROL, &tmp);
-	dev_info(&spi->dev, "Control Reg: 0x%02x\n", tmp);
-
-	ds3234_get_reg(&spi->dev, DS3234_REG_CONT_STAT, &tmp);
-	dev_info(&spi->dev, "Ctrl/Stat Reg: 0x%02x\n", tmp);
+	res = ds3234_read_byte(&spi->dev, DS3234_REG_CONTROL);
+	if (res < 0)
+		return res;
+	dev_info(&spi->dev, "Control Reg: 0x%02x\n", res);
 
-	rtc = devm_rtc_device_register(&spi->dev, "ds3234",
-				&ds3234_rtc_ops, THIS_MODULE);
-	if (IS_ERR(rtc))
-		return PTR_ERR(rtc);
+	res = ds3234_read_byte(&spi->dev, DS3234_REG_CONT_STAT);
+	if (res < 0)
+		return res;
+	dev_info(&spi->dev, "Ctrl/Stat Reg: 0x%02x\n", res);
 
-	spi_set_drvdata(spi, rtc);
+	return ds3232_probe(&spi->dev, &ds3234_ops, "ds3234");
+}
 
-	return 0;
+static int ds3234_remove(struct spi_device *spi)
+{
+	return ds3232_remove(&spi->dev);
 }
 
 static struct spi_driver ds3234_driver = {
@@ -161,8 +171,8 @@ static struct spi_driver ds3234_driver = {
 		.name	 = "ds3234",
 	},
 	.probe	 = ds3234_probe,
+	.remove = ds3234_remove,
 };
-
 module_spi_driver(ds3234_driver);
 
 MODULE_DESCRIPTION("DS3234 SPI RTC driver");
-- 
2.5.0

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