rtc: pcf2127: convert to use regmap
authorAkinobu Mita <akinobu.mita@gmail.com>
Mon, 14 Mar 2016 14:44:59 +0000 (23:44 +0900)
committerAlexandre Belloni <alexandre.belloni@free-electrons.com>
Mon, 14 Mar 2016 16:08:40 +0000 (17:08 +0100)
pcf2127 has selectable I2C-bus and SPI-bus interface support.
Currently rtc-pcf2127 driver only supports I2C.

This is preparation for support for SPI interface.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
drivers/rtc/rtc-pcf2127.c

index 629bfdf8c74540ac81a0c538f4b79e301bec8638..fa492cd84e2ae46d21aed497f594cb89fd0e765c 100644 (file)
@@ -19,6 +19,7 @@
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/regmap.h>
 
 #define PCF2127_REG_CTRL1       (0x00)  /* Control Register 1 */
 #define PCF2127_REG_CTRL2       (0x01)  /* Control Register 2 */
 
 #define PCF2127_OSF             BIT(7)  /* Oscillator Fail flag */
 
-static struct i2c_driver pcf2127_driver;
-
 struct pcf2127 {
        struct rtc_device *rtc;
+       struct regmap *regmap;
 };
 
 /*
  * In the routines that deal directly with the pcf2127 hardware, we use
  * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
  */
-static int pcf2127_get_datetime(struct i2c_client *client, struct rtc_time *tm)
+static int pcf2127_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
-       unsigned char buf[10] = { PCF2127_REG_CTRL1 };
+       struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
+       unsigned char buf[10];
+       int ret;
 
-       /* read registers */
-       if (i2c_master_send(client, buf, 1) != 1 ||
-               i2c_master_recv(client, buf, sizeof(buf)) != sizeof(buf)) {
-               dev_err(&client->dev, "%s: read error\n", __func__);
-               return -EIO;
+       ret = regmap_bulk_read(pcf2127->regmap, PCF2127_REG_CTRL1, buf,
+                               sizeof(buf));
+       if (ret) {
+               dev_err(dev, "%s: read error\n", __func__);
+               return ret;
        }
 
        if (buf[PCF2127_REG_CTRL3] & PCF2127_REG_CTRL3_BLF)
-               dev_info(&client->dev,
+               dev_info(dev,
                        "low voltage detected, check/replace RTC battery.\n");
 
        if (buf[PCF2127_REG_SC] & PCF2127_OSF) {
@@ -66,12 +68,12 @@ static int pcf2127_get_datetime(struct i2c_client *client, struct rtc_time *tm)
                 * no need clear the flag here,
                 * it will be cleared once the new date is saved
                 */
-               dev_warn(&client->dev,
+               dev_warn(dev,
                         "oscillator stop detected, date/time is not reliable\n");
                return -EINVAL;
        }
 
-       dev_dbg(&client->dev,
+       dev_dbg(dev,
                "%s: raw data is cr1=%02x, cr2=%02x, cr3=%02x, "
                "sec=%02x, min=%02x, hr=%02x, "
                "mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
@@ -91,7 +93,7 @@ static int pcf2127_get_datetime(struct i2c_client *client, struct rtc_time *tm)
        if (tm->tm_year < 70)
                tm->tm_year += 100;     /* assume we are in 1970...2069 */
 
-       dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
+       dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
                "mday=%d, mon=%d, year=%d, wday=%d\n",
                __func__,
                tm->tm_sec, tm->tm_min, tm->tm_hour,
@@ -100,20 +102,18 @@ static int pcf2127_get_datetime(struct i2c_client *client, struct rtc_time *tm)
        return rtc_valid_tm(tm);
 }
 
-static int pcf2127_set_datetime(struct i2c_client *client, struct rtc_time *tm)
+static int pcf2127_rtc_set_time(struct device *dev, struct rtc_time *tm)
 {
-       unsigned char buf[8];
+       struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
+       unsigned char buf[7];
        int i = 0, err;
 
-       dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
+       dev_dbg(dev, "%s: secs=%d, mins=%d, hours=%d, "
                "mday=%d, mon=%d, year=%d, wday=%d\n",
                __func__,
                tm->tm_sec, tm->tm_min, tm->tm_hour,
                tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
 
-       /* start register address */
-       buf[i++] = PCF2127_REG_SC;
-
        /* hours, minutes and seconds */
        buf[i++] = bin2bcd(tm->tm_sec); /* this will also clear OSF flag */
        buf[i++] = bin2bcd(tm->tm_min);
@@ -128,11 +128,11 @@ static int pcf2127_set_datetime(struct i2c_client *client, struct rtc_time *tm)
        buf[i++] = bin2bcd(tm->tm_year % 100);
 
        /* write register's data */
-       err = i2c_master_send(client, buf, i);
-       if (err != i) {
-               dev_err(&client->dev,
+       err = regmap_bulk_write(pcf2127->regmap, PCF2127_REG_SC, buf, i);
+       if (err) {
+               dev_err(dev,
                        "%s: err=%d", __func__, err);
-               return -EIO;
+               return err;
        }
 
        return 0;
@@ -142,26 +142,17 @@ static int pcf2127_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 static int pcf2127_rtc_ioctl(struct device *dev,
                                unsigned int cmd, unsigned long arg)
 {
-       struct i2c_client *client = to_i2c_client(dev);
-       unsigned char buf = PCF2127_REG_CTRL3;
+       struct pcf2127 *pcf2127 = dev_get_drvdata(dev);
        int touser;
        int ret;
 
        switch (cmd) {
        case RTC_VL_READ:
-               ret = i2c_master_send(client, &buf, 1);
-               if (!ret)
-                       ret = -EIO;
-               if (ret < 0)
-                       return ret;
-
-               ret = i2c_master_recv(client, &buf, 1);
-               if (!ret)
-                       ret = -EIO;
-               if (ret < 0)
+               ret = regmap_read(pcf2127->regmap, PCF2127_REG_CTRL3, &touser);
+               if (ret)
                        return ret;
 
-               touser = buf & PCF2127_REG_CTRL3_BLF ? 1 : 0;
+               touser = touser & PCF2127_REG_CTRL3_BLF ? 1 : 0;
 
                if (copy_to_user((void __user *)arg, &touser, sizeof(int)))
                        return -EFAULT;
@@ -174,52 +165,33 @@ static int pcf2127_rtc_ioctl(struct device *dev,
 #define pcf2127_rtc_ioctl NULL
 #endif
 
-static int pcf2127_rtc_read_time(struct device *dev, struct rtc_time *tm)
-{
-       return pcf2127_get_datetime(to_i2c_client(dev), tm);
-}
-
-static int pcf2127_rtc_set_time(struct device *dev, struct rtc_time *tm)
-{
-       return pcf2127_set_datetime(to_i2c_client(dev), tm);
-}
-
 static const struct rtc_class_ops pcf2127_rtc_ops = {
        .ioctl          = pcf2127_rtc_ioctl,
        .read_time      = pcf2127_rtc_read_time,
        .set_time       = pcf2127_rtc_set_time,
 };
 
-static int pcf2127_probe(struct i2c_client *client,
-                               const struct i2c_device_id *id)
+static int pcf2127_probe(struct device *dev, struct regmap *regmap,
+                       const char *name)
 {
        struct pcf2127 *pcf2127;
 
-       dev_dbg(&client->dev, "%s\n", __func__);
-
-       if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
-               return -ENODEV;
+       dev_dbg(dev, "%s\n", __func__);
 
-       pcf2127 = devm_kzalloc(&client->dev, sizeof(struct pcf2127),
-                               GFP_KERNEL);
+       pcf2127 = devm_kzalloc(dev, sizeof(*pcf2127), GFP_KERNEL);
        if (!pcf2127)
                return -ENOMEM;
 
-       i2c_set_clientdata(client, pcf2127);
+       pcf2127->regmap = regmap;
 
-       pcf2127->rtc = devm_rtc_device_register(&client->dev,
-                               pcf2127_driver.driver.name,
-                               &pcf2127_rtc_ops, THIS_MODULE);
+       dev_set_drvdata(dev, pcf2127);
+
+       pcf2127->rtc = devm_rtc_device_register(dev, name, &pcf2127_rtc_ops,
+                                               THIS_MODULE);
 
        return PTR_ERR_OR_ZERO(pcf2127->rtc);
 }
 
-static const struct i2c_device_id pcf2127_id[] = {
-       { "pcf2127", 0 },
-       { }
-};
-MODULE_DEVICE_TABLE(i2c, pcf2127_id);
-
 #ifdef CONFIG_OF
 static const struct of_device_id pcf2127_of_match[] = {
        { .compatible = "nxp,pcf2127" },
@@ -228,16 +200,118 @@ static const struct of_device_id pcf2127_of_match[] = {
 MODULE_DEVICE_TABLE(of, pcf2127_of_match);
 #endif
 
-static struct i2c_driver pcf2127_driver = {
+static int pcf2127_i2c_write(void *context, const void *data, size_t count)
+{
+       struct device *dev = context;
+       struct i2c_client *client = to_i2c_client(dev);
+       int ret;
+
+       ret = i2c_master_send(client, data, count);
+       if (ret != count)
+               return ret < 0 ? ret : -EIO;
+
+       return 0;
+}
+
+static int pcf2127_i2c_gather_write(void *context,
+                               const void *reg, size_t reg_size,
+                               const void *val, size_t val_size)
+{
+       struct device *dev = context;
+       struct i2c_client *client = to_i2c_client(dev);
+       int ret;
+       void *buf;
+
+       if (WARN_ON(reg_size != 1))
+               return -EINVAL;
+
+       buf = kmalloc(val_size + 1, GFP_KERNEL);
+       if (!buf)
+               return -ENOMEM;
+
+       memcpy(buf, reg, 1);
+       memcpy(buf + 1, val, val_size);
+
+       ret = i2c_master_send(client, buf, val_size + 1);
+       if (ret != val_size + 1)
+               return ret < 0 ? ret : -EIO;
+
+       return 0;
+}
+
+static int pcf2127_i2c_read(void *context, const void *reg, size_t reg_size,
+                               void *val, size_t val_size)
+{
+       struct device *dev = context;
+       struct i2c_client *client = to_i2c_client(dev);
+       int ret;
+
+       if (WARN_ON(reg_size != 1))
+               return -EINVAL;
+
+       ret = i2c_master_send(client, reg, 1);
+       if (ret != 1)
+               return ret < 0 ? ret : -EIO;
+
+       ret = i2c_master_recv(client, val, val_size);
+       if (ret != val_size)
+               return ret < 0 ? ret : -EIO;
+
+       return 0;
+}
+
+/*
+ * The reason we need this custom regmap_bus instead of using regmap_init_i2c()
+ * is that the STOP condition is required between set register address and
+ * read register data when reading from registers.
+ */
+static const struct regmap_bus pcf2127_i2c_regmap = {
+       .write = pcf2127_i2c_write,
+       .gather_write = pcf2127_i2c_gather_write,
+       .read = pcf2127_i2c_read,
+};
+
+static struct i2c_driver pcf2127_i2c_driver;
+
+static int pcf2127_i2c_probe(struct i2c_client *client,
+                               const struct i2c_device_id *id)
+{
+       struct regmap *regmap;
+       static const struct regmap_config config = {
+               .reg_bits = 8,
+               .val_bits = 8,
+       };
+
+       if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
+               return -ENODEV;
+
+       regmap = devm_regmap_init(&client->dev, &pcf2127_i2c_regmap,
+                                       &client->dev, &config);
+       if (IS_ERR(regmap)) {
+               dev_err(&client->dev, "%s: regmap allocation failed: %ld\n",
+                       __func__, PTR_ERR(regmap));
+               return PTR_ERR(regmap);
+       }
+
+       return pcf2127_probe(&client->dev, regmap,
+                               pcf2127_i2c_driver.driver.name);
+}
+
+static const struct i2c_device_id pcf2127_i2c_id[] = {
+       { "pcf2127", 0 },
+       { }
+};
+MODULE_DEVICE_TABLE(i2c, pcf2127_i2c_id);
+
+static struct i2c_driver pcf2127_i2c_driver = {
        .driver         = {
-               .name   = "rtc-pcf2127",
+               .name   = "rtc-pcf2127-i2c",
                .of_match_table = of_match_ptr(pcf2127_of_match),
        },
-       .probe          = pcf2127_probe,
-       .id_table       = pcf2127_id,
+       .probe          = pcf2127_i2c_probe,
+       .id_table       = pcf2127_i2c_id,
 };
-
-module_i2c_driver(pcf2127_driver);
+module_i2c_driver(pcf2127_i2c_driver);
 
 MODULE_AUTHOR("Renaud Cerrato <r.cerrato@til-technologies.fr>");
 MODULE_DESCRIPTION("NXP PCF2127 RTC driver");