rtc: merge ds3232 and ds3234

According to "Feature Comparison of the DS323x Real-Time Clocks"
(http://pdfserv.maximintegrated.com/en/an/AN5143.pdf), DS3232 and
DS3234 are very similar.

This merges rtc-ds3232 and rtc-ds3234 with using regmap.
This change also enables to support alarm for ds3234.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Suggested-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

4 files changed, 189 insertions, 194 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 9babb4ccd65b..987c50168fd8 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -247,16 +247,6 @@ config RTC_DRV_DS1672
           This driver can also be built as a module. If so, the module
           will be called rtc-ds1672.
 
-config RTC_DRV_DS3232
-        tristate "Dallas/Maxim DS3232"
-        help
-          If you say yes here you get support for Dallas Semiconductor
-          DS3232 real-time clock chips. If an interrupt is associated
-          with the device, the alarm functionality is supported.
-
-          This driver can also be built as a module.  If so, the module
-          will be called rtc-ds3232.
-
 config RTC_DRV_HYM8563
         tristate "Haoyu Microelectronics HYM8563"
         depends on OF
@@ -733,15 +723,6 @@ config RTC_DRV_MAX6902
           This driver can also be built as a module. If so, the module
           will be called rtc-max6902.
 
-config RTC_DRV_DS3234
-        tristate "Maxim/Dallas DS3234"
-        help
-          If you say yes here you get support for the
-          Maxim/Dallas DS3234 SPI RTC chip.
-
-          This driver can also be built as a module. If so, the module
-          will be called rtc-ds3234.
-
 config RTC_DRV_PCF2123
         tristate "NXP PCF2123"
         help
@@ -761,6 +742,31 @@ config RTC_DRV_MCP795
 
 endif # SPI_MASTER
 
+#
+# Helper to resolve issues with configs that have SPI enabled but I2C
+# modular.  See SND_SOC_I2C_AND_SPI for more information
+#
+config RTC_I2C_AND_SPI
+        tristate
+        default m if I2C=m
+        default y if I2C=y
+        default y if SPI_MASTER=y
+        select REGMAP_I2C if I2C
+        select REGMAP_SPI if SPI_MASTER
+
+comment "SPI and I2C RTC drivers"
+
+config RTC_DRV_DS3232
+        tristate "Dallas/Maxim DS3232/DS3234"
+        depends on RTC_I2C_AND_SPI
+        help
+          If you say yes here you get support for Dallas Semiconductor
+          DS3232 and DS3234 real-time clock chips. If an interrupt is associated
+          with the device, the alarm functionality is supported.
+
+          This driver can also be built as a module.  If so, the module
+          will be called rtc-ds3232.
+
 comment "Platform RTC drivers"
 
 # this 'CMOS' RTC driver is arch dependent because <asm-generic/rtc.h>
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 27229d2a466b..ea2833723fa9 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -60,7 +60,6 @@ obj-$(CONFIG_RTC_DRV_DS1685_FAMILY)	+= rtc-ds1685.o
 obj-$(CONFIG_RTC_DRV_DS1742)    += rtc-ds1742.o
 obj-$(CONFIG_RTC_DRV_DS2404)    += rtc-ds2404.o
 obj-$(CONFIG_RTC_DRV_DS3232)    += rtc-ds3232.o
-obj-$(CONFIG_RTC_DRV_DS3234)    += rtc-ds3234.o
 obj-$(CONFIG_RTC_DRV_EFI)       += rtc-efi.o
 obj-$(CONFIG_RTC_DRV_EM3027)    += rtc-em3027.o
 obj-$(CONFIG_RTC_DRV_EP93XX)    += rtc-ep93xx.o
diff --git a/drivers/rtc/rtc-ds3232.c b/drivers/rtc/rtc-ds3232.c
index 5791f996fa32..ca43bfcbb846 100644
--- a/drivers/rtc/rtc-ds3232.c
+++ b/drivers/rtc/rtc-ds3232.c
@@ -1,8 +1,9 @@
 /*
- * RTC client/driver for the Maxim/Dallas DS3232 Real-Time Clock over I2C
+ * RTC client/driver for the Maxim/Dallas DS3232/DS3234 Real-Time Clock
  *
  * Copyright (C) 2009-2011 Freescale Semiconductor.
  * Author: Jack Lan <jack.lan@freescale.com>
+ * Copyright (C) 2008 MIMOMax Wireless Ltd.
  *
  * This program is free software; you can redistribute  it and/or modify it
  * under  the terms of  the GNU General  Public License as published by the
@@ -16,6 +17,7 @@
 #include <linux/module.h>
 #include <linux/interrupt.h>
 #include <linux/i2c.h>
+#include <linux/spi/spi.h>
 #include <linux/rtc.h>
 #include <linux/bcd.h>
 #include <linux/workqueue.h>
@@ -481,6 +483,8 @@ static const struct dev_pm_ops ds3232_pm_ops = {
         SET_SYSTEM_SLEEP_PM_OPS(ds3232_suspend, ds3232_resume)
 };
 
+#if IS_ENABLED(CONFIG_I2C)
+
 static int ds3232_i2c_probe(struct i2c_client *client,
                             const struct i2c_device_id *id)
 {
@@ -520,8 +524,165 @@ static struct i2c_driver ds3232_driver = {
         .remove = ds3232_i2c_remove,
         .id_table = ds3232_id,
 };
-module_i2c_driver(ds3232_driver);
+
+static int ds3232_register_driver(void)
+{
+        return i2c_add_driver(&ds3232_driver);
+}
+
+static void ds3232_unregister_driver(void)
+{
+        i2c_del_driver(&ds3232_driver);
+}
+
+#else
+
+static int ds3232_register_driver(void)
+{
+        return 0;
+}
+
+static void ds3232_unregister_driver(void)
+{
+}
+
+#endif
+
+#if IS_ENABLED(CONFIG_SPI_MASTER)
+
+static int ds3234_probe(struct spi_device *spi)
+{
+        int res;
+        unsigned int tmp;
+        static const struct regmap_config config = {
+                .reg_bits = 8,
+                .val_bits = 8,
+                .write_flag_mask = 0x80,
+        };
+        struct regmap *regmap;
+
+        regmap = devm_regmap_init_spi(spi, &config);
+        if (IS_ERR(regmap)) {
+                dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n",
+                        __func__, PTR_ERR(regmap));
+                return PTR_ERR(regmap);
+        }
+
+        spi->mode = SPI_MODE_3;
+        spi->bits_per_word = 8;
+        spi_setup(spi);
+
+        res = regmap_read(regmap, DS3232_REG_SECONDS, &tmp);
+        if (res)
+                return res;
+
+        /* Control settings
+         *
+         * CONTROL_REG
+         * BIT 7        6       5       4       3       2       1       0
+         *     EOSC     BBSQW   CONV    RS2     RS1     INTCN   A2IE    A1IE
+         *
+         *     0        0       0       1       1       1       0       0
+         *
+         * CONTROL_STAT_REG
+         * BIT 7        6       5       4       3       2       1       0
+         *     OSF      BB32kHz CRATE1  CRATE0  EN32kHz BSY     A2F     A1F
+         *
+         *     1        0       0       0       1       0       0       0
+         */
+        res = regmap_read(regmap, DS3232_REG_CR, &tmp);
+        if (res)
+                return res;
+        res = regmap_write(regmap, DS3232_REG_CR, tmp & 0x1c);
+        if (res)
+                return res;
+
+        res = regmap_read(regmap, DS3232_REG_SR, &tmp);
+        if (res)
+                return res;
+        res = regmap_write(regmap, DS3232_REG_SR, tmp & 0x88);
+        if (res)
+                return res;
+
+        /* Print our settings */
+        res = regmap_read(regmap, DS3232_REG_CR, &tmp);
+        if (res)
+                return res;
+        dev_info(&spi->dev, "Control Reg: 0x%02x\n", tmp);
+
+        res = regmap_read(regmap, DS3232_REG_SR, &tmp);
+        if (res)
+                return res;
+        dev_info(&spi->dev, "Ctrl/Stat Reg: 0x%02x\n", tmp);
+
+        return ds3232_probe(&spi->dev, regmap, spi->irq, "ds3234");
+}
+
+static int ds3234_remove(struct spi_device *spi)
+{
+        return ds3232_remove(&spi->dev);
+}
+
+static struct spi_driver ds3234_driver = {
+        .driver = {
+                .name    = "ds3234",
+        },
+        .probe   = ds3234_probe,
+        .remove = ds3234_remove,
+};
+
+static int ds3234_register_driver(void)
+{
+        return spi_register_driver(&ds3234_driver);
+}
+
+static void ds3234_unregister_driver(void)
+{
+        spi_unregister_driver(&ds3234_driver);
+}
+
+#else
+
+static int ds3234_register_driver(void)
+{
+        return 0;
+}
+
+static void ds3234_unregister_driver(void)
+{
+}
+
+#endif
+
+static int __init ds323x_init(void)
+{
+        int ret;
+
+        ret = ds3232_register_driver();
+        if (ret) {
+                pr_err("Failed to register ds3232 driver: %d\n", ret);
+                return ret;
+        }
+
+        ret = ds3234_register_driver();
+        if (ret) {
+                pr_err("Failed to register ds3234 driver: %d\n", ret);
+                ds3232_unregister_driver();
+        }
+
+        return ret;
+}
+module_init(ds323x_init)
+
+static void __exit ds323x_exit(void)
+{
+        ds3234_unregister_driver();
+        ds3232_unregister_driver();
+}
+module_exit(ds323x_exit)
 
 MODULE_AUTHOR("Srikanth Srinivasan <srikanth.srinivasan@freescale.com>");
-MODULE_DESCRIPTION("Maxim/Dallas DS3232 RTC Driver");
+MODULE_AUTHOR("Dennis Aberilla <denzzzhome@yahoo.com>");
+MODULE_DESCRIPTION("Maxim/Dallas DS3232/DS3234 RTC Driver");
 MODULE_LICENSE("GPL");
+MODULE_ALIAS("spi:ds3234");
diff --git a/drivers/rtc/rtc-ds3234.c b/drivers/rtc/rtc-ds3234.c
deleted file mode 100644
index 570ab28fc354..000000000000
--- a/drivers/rtc/rtc-ds3234.c
+++ /dev/null
@@ -1,171 +0,0 @@
-/* rtc-ds3234.c
- *
- * Driver for Dallas Semiconductor (DS3234) SPI RTC with Integrated Crystal
- * and SRAM.
- *
- * Copyright (C) 2008 MIMOMax Wireless Ltd.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- */
-
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/device.h>
-#include <linux/platform_device.h>
-#include <linux/rtc.h>
-#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 */
-
-#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)
-{
-        struct spi_device *spi = to_spi_device(dev);
-        unsigned char buf[2];
-
-        /* MSB must be '1' to indicate write */
-        buf[0] = address | 0x80;
-        buf[1] = data;
-
-        return spi_write_then_read(spi, buf, 2, NULL, 0);
-}
-
-static int ds3234_get_reg(struct device *dev, unsigned char address,
-                                unsigned char *data)
-{
-        struct spi_device *spi = to_spi_device(dev);
-
-        *data = address & 0x7f;
-
-        return spi_write_then_read(spi, data, 1, data, 1);
-}
-
-static int ds3234_read_time(struct device *dev, struct rtc_time *dt)
-{
-        int err;
-        unsigned char buf[8];
-        struct spi_device *spi = to_spi_device(dev);
-
-        buf[0] = 0x00; /* Start address */
-
-        err = spi_write_then_read(spi, buf, 1, buf, 8);
-        if (err != 0)
-                return err;
-
-        /* 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 */
-
-        return rtc_valid_tm(dt);
-}
-
-static int ds3234_set_time(struct device *dev, struct rtc_time *dt)
-{
-        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));
-
-        /* Assume 20YY although we just want to make sure not to go negative. */
-        if (dt->tm_year > 100)
-                dt->tm_year -= 100;
-
-        ds3234_set_reg(dev, DS3234_REG_YEAR, bin2bcd(dt->tm_year));
-
-        return 0;
-}
-
-static const struct rtc_class_ops ds3234_rtc_ops = {
-        .read_time      = ds3234_read_time,
-        .set_time       = ds3234_set_time,
-};
-
-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)
-                return res;
-
-        /* Control settings
-         *
-         * CONTROL_REG
-         * BIT 7        6       5       4       3       2       1       0
-         *     EOSC     BBSQW   CONV    RS2     RS1     INTCN   A2IE    A1IE
-         *
-         *     0        0       0       1       1       1       0       0
-         *
-         * CONTROL_STAT_REG
-         * BIT 7        6       5       4       3       2       1       0
-         *     OSF      BB32kHz CRATE1  CRATE0  EN32kHz BSY     A2F     A1F
-         *
-         *     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);
-
-        ds3234_get_reg(&spi->dev, DS3234_REG_CONT_STAT, &tmp);
-        ds3234_set_reg(&spi->dev, DS3234_REG_CONT_STAT, tmp & 0x88);
-
-        /* 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);
-
-        rtc = devm_rtc_device_register(&spi->dev, "ds3234",
-                                &ds3234_rtc_ops, THIS_MODULE);
-        if (IS_ERR(rtc))
-                return PTR_ERR(rtc);
-
-        spi_set_drvdata(spi, rtc);
-
-        return 0;
-}
-
-static struct spi_driver ds3234_driver = {
-        .driver = {
-                .name    = "ds3234",
-        },
-        .probe   = ds3234_probe,
-};
-
-module_spi_driver(ds3234_driver);
-
-MODULE_DESCRIPTION("DS3234 SPI RTC driver");
-MODULE_AUTHOR("Dennis Aberilla <denzzzhome@yahoo.com>");
-MODULE_LICENSE("GPL");
-MODULE_ALIAS("spi:ds3234");