[PATCH 1/4] rtc: ds1307: add support for mcp7940x chips

From: Tomas Novotny
Date: Mon Nov 24 2014 - 10:59:52 EST


MCP7940x is same RTC as MCP7941x. The difference is that MCP7941x chips
contain additional EEPROM on a different i2c address.

DS1307 driver already supports MCP7941x, so just add a new i2c device id
and rename functions and defines accordingly.

Signed-off-by: Tomas Novotny <tomas@xxxxxxxxxx>
---
drivers/rtc/rtc-ds1307.c | 127 ++++++++++++++++++++++++-----------------------
1 file changed, 64 insertions(+), 63 deletions(-)

diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index bb43cf7..4ffabb3 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -35,7 +35,7 @@ enum ds_type {
ds_1388,
ds_3231,
m41t00,
- mcp7941x,
+ mcp794xx,
rx_8025,
last_ds_type /* always last */
/* rs5c372 too? different address... */
@@ -46,7 +46,7 @@ enum ds_type {
#define DS1307_REG_SECS 0x00 /* 00-59 */
# define DS1307_BIT_CH 0x80
# define DS1340_BIT_nEOSC 0x80
-# define MCP7941X_BIT_ST 0x80
+# define MCP794XX_BIT_ST 0x80
#define DS1307_REG_MIN 0x01 /* 00-59 */
#define DS1307_REG_HOUR 0x02 /* 00-23, or 1-12{am,pm} */
# define DS1307_BIT_12HR 0x40 /* in REG_HOUR */
@@ -54,7 +54,7 @@ enum ds_type {
# define DS1340_BIT_CENTURY_EN 0x80 /* in REG_HOUR */
# define DS1340_BIT_CENTURY 0x40 /* in REG_HOUR */
#define DS1307_REG_WDAY 0x03 /* 01-07 */
-# define MCP7941X_BIT_VBATEN 0x08
+# define MCP794XX_BIT_VBATEN 0x08
#define DS1307_REG_MDAY 0x04 /* 01-31 */
#define DS1307_REG_MONTH 0x05 /* 01-12 */
# define DS1337_BIT_CENTURY 0x80 /* in REG_MONTH */
@@ -159,7 +159,7 @@ static struct chip_desc chips[last_ds_type] = {
[ds_3231] = {
.alarm = 1,
},
- [mcp7941x] = {
+ [mcp794xx] = {
.alarm = 1,
/* this is battery backed SRAM */
.nvram_offset = 0x20,
@@ -176,7 +176,8 @@ static const struct i2c_device_id ds1307_id[] = {
{ "ds1340", ds_1340 },
{ "ds3231", ds_3231 },
{ "m41t00", m41t00 },
- { "mcp7941x", mcp7941x },
+ { "mcp7940x", mcp794xx },
+ { "mcp7941x", mcp794xx },
{ "pt7c4338", ds_1307 },
{ "rx8025", rx_8025 },
{ }
@@ -439,14 +440,14 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t)
buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN
| DS1340_BIT_CENTURY;
break;
- case mcp7941x:
+ case mcp794xx:
/*
* these bits were cleared when preparing the date/time
* values and need to be set again before writing the
* buffer out to the device.
*/
- buf[DS1307_REG_SECS] |= MCP7941X_BIT_ST;
- buf[DS1307_REG_WDAY] |= MCP7941X_BIT_VBATEN;
+ buf[DS1307_REG_SECS] |= MCP794XX_BIT_ST;
+ buf[DS1307_REG_WDAY] |= MCP794XX_BIT_VBATEN;
break;
default:
break;
@@ -614,26 +615,26 @@ static const struct rtc_class_ops ds13xx_rtc_ops = {
/*----------------------------------------------------------------------*/

/*
- * Alarm support for mcp7941x devices.
+ * Alarm support for mcp794xx devices.
*/

-#define MCP7941X_REG_CONTROL 0x07
-# define MCP7941X_BIT_ALM0_EN 0x10
-# define MCP7941X_BIT_ALM1_EN 0x20
-#define MCP7941X_REG_ALARM0_BASE 0x0a
-#define MCP7941X_REG_ALARM0_CTRL 0x0d
-#define MCP7941X_REG_ALARM1_BASE 0x11
-#define MCP7941X_REG_ALARM1_CTRL 0x14
-# define MCP7941X_BIT_ALMX_IF (1 << 3)
-# define MCP7941X_BIT_ALMX_C0 (1 << 4)
-# define MCP7941X_BIT_ALMX_C1 (1 << 5)
-# define MCP7941X_BIT_ALMX_C2 (1 << 6)
-# define MCP7941X_BIT_ALMX_POL (1 << 7)
-# define MCP7941X_MSK_ALMX_MATCH (MCP7941X_BIT_ALMX_C0 | \
- MCP7941X_BIT_ALMX_C1 | \
- MCP7941X_BIT_ALMX_C2)
-
-static void mcp7941x_work(struct work_struct *work)
+#define MCP794XX_REG_CONTROL 0x07
+# define MCP794XX_BIT_ALM0_EN 0x10
+# define MCP794XX_BIT_ALM1_EN 0x20
+#define MCP794XX_REG_ALARM0_BASE 0x0a
+#define MCP794XX_REG_ALARM0_CTRL 0x0d
+#define MCP794XX_REG_ALARM1_BASE 0x11
+#define MCP794XX_REG_ALARM1_CTRL 0x14
+# define MCP794XX_BIT_ALMX_IF (1 << 3)
+# define MCP794XX_BIT_ALMX_C0 (1 << 4)
+# define MCP794XX_BIT_ALMX_C1 (1 << 5)
+# define MCP794XX_BIT_ALMX_C2 (1 << 6)
+# define MCP794XX_BIT_ALMX_POL (1 << 7)
+# define MCP794XX_MSK_ALMX_MATCH (MCP794XX_BIT_ALMX_C0 | \
+ MCP794XX_BIT_ALMX_C1 | \
+ MCP794XX_BIT_ALMX_C2)
+
+static void mcp794xx_work(struct work_struct *work)
{
struct ds1307 *ds1307 = container_of(work, struct ds1307, work);
struct i2c_client *client = ds1307->client;
@@ -642,22 +643,22 @@ static void mcp7941x_work(struct work_struct *work)
mutex_lock(&ds1307->rtc->ops_lock);

/* Check and clear alarm 0 interrupt flag. */
- reg = i2c_smbus_read_byte_data(client, MCP7941X_REG_ALARM0_CTRL);
+ reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_ALARM0_CTRL);
if (reg < 0)
goto out;
- if (!(reg & MCP7941X_BIT_ALMX_IF))
+ if (!(reg & MCP794XX_BIT_ALMX_IF))
goto out;
- reg &= ~MCP7941X_BIT_ALMX_IF;
- ret = i2c_smbus_write_byte_data(client, MCP7941X_REG_ALARM0_CTRL, reg);
+ reg &= ~MCP794XX_BIT_ALMX_IF;
+ ret = i2c_smbus_write_byte_data(client, MCP794XX_REG_ALARM0_CTRL, reg);
if (ret < 0)
goto out;

/* Disable alarm 0. */
- reg = i2c_smbus_read_byte_data(client, MCP7941X_REG_CONTROL);
+ reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_CONTROL);
if (reg < 0)
goto out;
- reg &= ~MCP7941X_BIT_ALM0_EN;
- ret = i2c_smbus_write_byte_data(client, MCP7941X_REG_CONTROL, reg);
+ reg &= ~MCP794XX_BIT_ALM0_EN;
+ ret = i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, reg);
if (ret < 0)
goto out;

@@ -669,7 +670,7 @@ out:
mutex_unlock(&ds1307->rtc->ops_lock);
}

-static int mcp7941x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
+static int mcp794xx_read_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct i2c_client *client = to_i2c_client(dev);
struct ds1307 *ds1307 = i2c_get_clientdata(client);
@@ -680,11 +681,11 @@ static int mcp7941x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
return -EINVAL;

/* Read control and alarm 0 registers. */
- ret = ds1307->read_block_data(client, MCP7941X_REG_CONTROL, 10, regs);
+ ret = ds1307->read_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
if (ret < 0)
return ret;

- t->enabled = !!(regs[0] & MCP7941X_BIT_ALM0_EN);
+ t->enabled = !!(regs[0] & MCP794XX_BIT_ALM0_EN);

/* Report alarm 0 time assuming 24-hour and day-of-month modes. */
t->time.tm_sec = bcd2bin(ds1307->regs[3] & 0x7f);
@@ -701,14 +702,14 @@ static int mcp7941x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
"enabled=%d polarity=%d irq=%d match=%d\n", __func__,
t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
t->time.tm_wday, t->time.tm_mday, t->time.tm_mon, t->enabled,
- !!(ds1307->regs[6] & MCP7941X_BIT_ALMX_POL),
- !!(ds1307->regs[6] & MCP7941X_BIT_ALMX_IF),
- (ds1307->regs[6] & MCP7941X_MSK_ALMX_MATCH) >> 4);
+ !!(ds1307->regs[6] & MCP794XX_BIT_ALMX_POL),
+ !!(ds1307->regs[6] & MCP794XX_BIT_ALMX_IF),
+ (ds1307->regs[6] & MCP794XX_MSK_ALMX_MATCH) >> 4);

return 0;
}

-static int mcp7941x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
+static int mcp794xx_set_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct i2c_client *client = to_i2c_client(dev);
struct ds1307 *ds1307 = i2c_get_clientdata(client);
@@ -725,7 +726,7 @@ static int mcp7941x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
t->enabled, t->pending);

/* Read control and alarm 0 registers. */
- ret = ds1307->read_block_data(client, MCP7941X_REG_CONTROL, 10, regs);
+ ret = ds1307->read_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
if (ret < 0)
return ret;

@@ -738,23 +739,23 @@ static int mcp7941x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
regs[8] = bin2bcd(t->time.tm_mon) + 1;

/* Clear the alarm 0 interrupt flag. */
- regs[6] &= ~MCP7941X_BIT_ALMX_IF;
+ regs[6] &= ~MCP794XX_BIT_ALMX_IF;
/* Set alarm match: second, minute, hour, day, date, month. */
- regs[6] |= MCP7941X_MSK_ALMX_MATCH;
+ regs[6] |= MCP794XX_MSK_ALMX_MATCH;

if (t->enabled)
- regs[0] |= MCP7941X_BIT_ALM0_EN;
+ regs[0] |= MCP794XX_BIT_ALM0_EN;
else
- regs[0] &= ~MCP7941X_BIT_ALM0_EN;
+ regs[0] &= ~MCP794XX_BIT_ALM0_EN;

- ret = ds1307->write_block_data(client, MCP7941X_REG_CONTROL, 10, regs);
+ ret = ds1307->write_block_data(client, MCP794XX_REG_CONTROL, 10, regs);
if (ret < 0)
return ret;

return 0;
}

-static int mcp7941x_alarm_irq_enable(struct device *dev, unsigned int enabled)
+static int mcp794xx_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct i2c_client *client = to_i2c_client(dev);
struct ds1307 *ds1307 = i2c_get_clientdata(client);
@@ -763,24 +764,24 @@ static int mcp7941x_alarm_irq_enable(struct device *dev, unsigned int enabled)
if (!test_bit(HAS_ALARM, &ds1307->flags))
return -EINVAL;

- reg = i2c_smbus_read_byte_data(client, MCP7941X_REG_CONTROL);
+ reg = i2c_smbus_read_byte_data(client, MCP794XX_REG_CONTROL);
if (reg < 0)
return reg;

if (enabled)
- reg |= MCP7941X_BIT_ALM0_EN;
+ reg |= MCP794XX_BIT_ALM0_EN;
else
- reg &= ~MCP7941X_BIT_ALM0_EN;
+ reg &= ~MCP794XX_BIT_ALM0_EN;

- return i2c_smbus_write_byte_data(client, MCP7941X_REG_CONTROL, reg);
+ return i2c_smbus_write_byte_data(client, MCP794XX_REG_CONTROL, reg);
}

-static const struct rtc_class_ops mcp7941x_rtc_ops = {
+static const struct rtc_class_ops mcp794xx_rtc_ops = {
.read_time = ds1307_get_time,
.set_time = ds1307_set_time,
- .read_alarm = mcp7941x_read_alarm,
- .set_alarm = mcp7941x_set_alarm,
- .alarm_irq_enable = mcp7941x_alarm_irq_enable,
+ .read_alarm = mcp794xx_read_alarm,
+ .set_alarm = mcp794xx_set_alarm,
+ .alarm_irq_enable = mcp794xx_alarm_irq_enable,
};

/*----------------------------------------------------------------------*/
@@ -1049,10 +1050,10 @@ static int ds1307_probe(struct i2c_client *client,
case ds_1388:
ds1307->offset = 1; /* Seconds starts at 1 */
break;
- case mcp7941x:
- rtc_ops = &mcp7941x_rtc_ops;
+ case mcp794xx:
+ rtc_ops = &mcp794xx_rtc_ops;
if (ds1307->client->irq > 0 && chip->alarm) {
- INIT_WORK(&ds1307->work, mcp7941x_work);
+ INIT_WORK(&ds1307->work, mcp794xx_work);
want_irq = true;
}
break;
@@ -1117,18 +1118,18 @@ read_rtc:
dev_warn(&client->dev, "SET TIME!\n");
}
break;
- case mcp7941x:
+ case mcp794xx:
/* make sure that the backup battery is enabled */
- if (!(ds1307->regs[DS1307_REG_WDAY] & MCP7941X_BIT_VBATEN)) {
+ if (!(ds1307->regs[DS1307_REG_WDAY] & MCP794XX_BIT_VBATEN)) {
i2c_smbus_write_byte_data(client, DS1307_REG_WDAY,
ds1307->regs[DS1307_REG_WDAY]
- | MCP7941X_BIT_VBATEN);
+ | MCP794XX_BIT_VBATEN);
}

/* clock halted? turn it on, so clock can tick. */
- if (!(tmp & MCP7941X_BIT_ST)) {
+ if (!(tmp & MCP794XX_BIT_ST)) {
i2c_smbus_write_byte_data(client, DS1307_REG_SECS,
- MCP7941X_BIT_ST);
+ MCP794XX_BIT_ST);
dev_warn(&client->dev, "SET TIME!\n");
goto read_rtc;
}
--
2.1.2

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