rtc: ds1307: add support for mcp7940x chips

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@novotny.cz>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index bb43cf7..4ffabb3 100644 (file)
--- 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;
                }