>From 54dad3ebbce5aba4d749a14d8173e94297e14b1a Mon Sep 17 00:00:00 2001
From: Raghavendra Ganiga <ravi23gan...@gmail.com>
Date: Sun, 13 Apr 2014 20:02:59 +0530
Subject: [PATCH] rtc: add support for maxim dallas rtc ds1343 and ds1344

This is patch to add support for
maxim dallas rtc ds1343 and ds1344

Signed-off-by: Raghavendra Chandra Ganiga <ravi23gan...@gmail.com>
---
 drivers/rtc/Kconfig      |   10 +
 drivers/rtc/Makefile     |    1 +
 drivers/rtc/rtc-ds1343.c |  619 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 630 insertions(+)
 create mode 100644 drivers/rtc/rtc-ds1343.c

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 2e565f8..eb5cdcb 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -573,6 +573,16 @@ config RTC_DRV_DS1305
          This driver can also be built as a module. If so, the module
          will be called rtc-ds1305.
 
+config RTC_DRV_DS1343
+       tristate "Dallas/Maxim DS1343/DS1344"
+       help
+         If you say yes here you get support for the
+         Dallas/Maxim DS1343 and DS1344 real time clock chips.
+         Support for trickle charger, alarm is provided.
+
+         This driver can also be built as a module. If so, the module
+         will be called rtc-ds1343.
+
 config RTC_DRV_DS1347
        tristate "Dallas/Maxim DS1347"
        help
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 40a0991..a8daf6c 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -40,6 +40,7 @@ obj-$(CONFIG_RTC_DRV_DS1286)  += rtc-ds1286.o
 obj-$(CONFIG_RTC_DRV_DS1302)   += rtc-ds1302.o
 obj-$(CONFIG_RTC_DRV_DS1305)   += rtc-ds1305.o
 obj-$(CONFIG_RTC_DRV_DS1307)   += rtc-ds1307.o
+obj-$(CONFIG_RTC_DRV_DS1343)   += rtc-ds1343.o
 obj-$(CONFIG_RTC_DRV_DS1347)   += rtc-ds1347.o
 obj-$(CONFIG_RTC_DRV_DS1374)   += rtc-ds1374.o
 obj-$(CONFIG_RTC_DRV_DS1390)   += rtc-ds1390.o
diff --git a/drivers/rtc/rtc-ds1343.c b/drivers/rtc/rtc-ds1343.c
new file mode 100644
index 0000000..9bd9313
--- /dev/null
+++ b/drivers/rtc/rtc-ds1343.c
@@ -0,0 +1,619 @@
+/* rtc-ds1343.c
+ *
+ * Driver for Dallas Semiconductor DS1343 Low Current, SPI Compatible
+ * Real Time Clock
+ *
+ * Author : Raghavendra Chandra Ganiga <ravi23gan...@gmail.com>
+ *
+ * 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/interrupt.h>
+#include <linux/device.h>
+#include <linux/spi/spi.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+#include <linux/pm.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+#define DS1343_DRV_VERSION     "01.00"
+
+/* RTC DS1343 Registers */
+#define DS1343_SECONDS_REG     0x00
+#define DS1343_MINUTES_REG     0x01
+#define DS1343_HOURS_REG       0x02
+#define DS1343_DAY_REG         0x03
+#define DS1343_DATE_REG                0x04
+#define DS1343_MONTH_REG       0x05
+#define DS1343_YEAR_REG                0x06
+#define DS1343_ALM0_SEC_REG    0x07
+#define DS1343_ALM0_MIN_REG    0x08
+#define DS1343_ALM0_HOUR_REG   0x09
+#define DS1343_ALM0_DAY_REG    0x0A
+#define DS1343_ALM1_SEC_REG    0x0B
+#define DS1343_ALM1_MIN_REG    0x0C
+#define DS1343_ALM1_HOUR_REG   0x0D
+#define DS1343_ALM1_DAY_REG    0x0E
+#define DS1343_CONTROL_REG     0x0F
+#define DS1343_STATUS_REG      0x10
+#define DS1343_TRICKLE_REG     0x11
+
+/* DS1343 Control Registers bits */
+#define DS1343_EOSC            0x80
+#define DS1343_DOSF            0x20
+#define DS1343_EGFIL           0x10
+#define DS1343_SQW             0x08
+#define DS1343_INTCN           0x04
+#define DS1343_A1IE            0x02
+#define DS1343_A0IE            0x01
+
+/* DS1343 Status Registers bits */
+#define DS1343_OSF             0x80
+#define DS1343_IRQF1           0x02
+#define DS1343_IRQF0           0x01
+
+/* DS1343 Trickle Charger Registers bits */
+#define DS1343_TRICKLE_MAGIC   0xa0
+#define DS1343_TRICKLE_DS1     0x08
+#define DS1343_TRICKLE_1K      0x01
+#define DS1343_TRICKLE_2K      0x02
+#define DS1343_TRICKLE_4K      0x03
+
+static const struct spi_device_id ds1343_id[] = {
+       { "ds1343", 0 },
+       { "ds1344", 1 },
+       { }
+};
+MODULE_DEVICE_TABLE(spi, ds1343_id);
+
+struct ds1343_priv {
+       struct spi_device *spi;
+       struct rtc_device *rtc;
+       struct mutex mutex;
+       struct work_struct work;
+       unsigned int irqen;
+       int alarm_sec;
+       int alarm_min;
+       int alarm_hour;
+       int alarm_mday;
+};
+
+static int ds1343_get_reg(struct device *dev, unsigned char address,
+                               unsigned char *buf)
+{
+       struct spi_device *spi = to_spi_device(dev);
+
+       /* MSB of the spi address                        _
+          in this rtc should be zero for read operation R/W */
+       *buf = address;
+
+       return spi_write_then_read(spi, buf, 1, buf, 1);
+}
+
+static int ds1343_set_reg(struct device *dev, unsigned char address,
+                               unsigned char data)
+{
+       struct spi_device *spi = to_spi_device(dev);
+       unsigned char buf[2];
+
+       /* MSB of the spi address                        _
+          in this rtc should be one for write operation R/W */
+       buf[0] = address | 0x80;
+       buf[1] = data;
+
+       return spi_write_then_read(spi, buf, 2, NULL, 0);
+}
+
+static int ds1343_ioctl(struct device *dev, unsigned int cmd, unsigned long 
arg)
+{
+       switch (cmd) {
+#ifdef RTC_SET_CHARGE
+       case RTC_SET_CHARGE:
+       {
+               int val;
+
+               if (copy_from_user(&val, (int __user *)arg, sizeof(int)))
+                       return -EFAULT;
+
+               return ds1343_set_reg(dev, DS1343_TRICKLE_REG, val);
+       }
+       break;
+#endif
+       }
+
+       return -ENOIOCTLCMD;
+}
+
+#ifdef CONFIG_PROC_FS
+
+static int ds1343_proc(struct device *dev, struct seq_file *seq)
+{
+       struct ds1343_priv *priv = dev_get_drvdata(dev);
+       struct  spi_device *spi = priv->spi;
+       unsigned char data, alarm_mode = 0;
+       const char *alarm_str, *diodes = "disabled", *resistors = " ";
+
+       ds1343_get_reg(&spi->dev, DS1343_CONTROL_REG, &data);
+
+       seq_printf(seq,
+                       "oscillator\t: %s\n"
+                       "disable_oscillator_stop_flag\t: %s\n"
+                       "glitch_filter\t: %s\n"
+                       "square_wave\t: %s\n"
+                       "alarm_enable\t: %s\n",
+                       (data & DS1343_EOSC) ? "disabled" : "enabled",
+                       (data & DS1343_DOSF) ? "disabled" : "enabled",
+                       (data & DS1343_EGFIL) ? "enabled" : "disabled",
+                       (data & DS1343_SQW) ? "enabled" : "disabled",
+                       (data & DS1343_A0IE) ? "enabled" : "disabled");
+
+       ds1343_get_reg(&spi->dev, DS1343_ALM0_SEC_REG, &data);
+       alarm_mode = (data & 0x80) >> 4;
+
+       ds1343_get_reg(&spi->dev, DS1343_ALM0_MIN_REG, &data);
+       alarm_mode |= (data & 0x80) >> 5;
+
+       ds1343_get_reg(&spi->dev, DS1343_ALM0_HOUR_REG, &data);
+       alarm_mode |= (data & 0x80) >> 6;
+
+       ds1343_get_reg(&spi->dev, DS1343_ALM0_DAY_REG, &data);
+       alarm_mode |= (data & 0x80) >> 7;
+
+       switch (alarm_mode) {
+       case 15:
+               alarm_str = "each second";
+               break;
+
+       case 7:
+               alarm_str = "seconds match";
+               break;
+
+       case 3:
+               alarm_str = "minutes and seconds match";
+               break;
+
+       case 1:
+               alarm_str = "hours, minutes and seconds match";
+               break;
+
+       case 0:
+               alarm_str = "day, hours, minutes and seconds match";
+               break;
+
+       default:
+               alarm_str = "invalid";
+               break;
+       }
+
+       seq_printf(seq, "alarm_mode\t: %s\n", alarm_str);
+
+       ds1343_get_reg(dev, DS1343_STATUS_REG, &data);
+       seq_printf(seq,
+                       "alarm_pending\t: %s\n"
+                       "oscillator_stop_flag\t: %s\n",
+                       (data & DS1343_IRQF0) ? "yes" : "no",
+                       (data & DS1343_OSF) ? "1" : "0");
+
+       ds1343_get_reg(dev, DS1343_TRICKLE_REG, &data);
+
+       if ((data & 0xf0) == DS1343_TRICKLE_MAGIC) {
+               switch (data & 0x0c) {
+               case DS1343_TRICKLE_DS1:
+                       diodes = "one diode,";
+                       break;
+
+               default:
+                       diodes = "no diode,";
+                       break;
+               }
+
+               switch (data & 0x03) {
+               case DS1343_TRICKLE_1K:
+                       resistors = "1k Ohm";
+                       break;
+
+               case DS1343_TRICKLE_2K:
+                       resistors = "2k Ohm";
+                       break;
+
+               case DS1343_TRICKLE_4K:
+                       resistors = "4k Ohm";
+                       break;
+
+               default:
+                       diodes = "disabled";
+                       break;
+               }
+       }
+
+       seq_printf(seq,
+                       "trickle_charger\t: %s %s\n",
+                       diodes, resistors);
+
+       return 0;
+}
+
+#else
+
+#define ds1343_proc NULL
+
+#endif
+
+static int ds1343_read_time(struct device *dev, struct rtc_time *dt)
+{
+       struct spi_device *spi = to_spi_device(dev);
+       unsigned char buf[7];
+       int res;
+
+       buf[0] = DS1343_SECONDS_REG;
+
+       res = spi_write_then_read(spi, buf, 1, buf, 7);
+       if (res)
+               return res;
+
+       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;
+       dt->tm_mday     = bcd2bin(buf[4]);
+       dt->tm_mon      = bcd2bin(buf[5] & 0x1F) - 1;
+       dt->tm_year     = bcd2bin(buf[6]) + 100; /* year offset from 1900 */
+
+       return rtc_valid_tm(dt);
+}
+
+static int ds1343_set_time(struct device *dev, struct rtc_time *dt)
+{
+       int res;
+       res = ds1343_set_reg(dev, DS1343_SECONDS_REG,
+                               bin2bcd(dt->tm_sec));
+       if (res)
+               return res;
+
+       res = ds1343_set_reg(dev, DS1343_MINUTES_REG,
+                               bin2bcd(dt->tm_min));
+       if (res)
+               return res;
+
+       res = ds1343_set_reg(dev, DS1343_HOURS_REG,
+                               bin2bcd(dt->tm_hour) & 0x3F);
+       if (res)
+               return res;
+
+       res = ds1343_set_reg(dev, DS1343_DAY_REG,
+                               bin2bcd(dt->tm_wday + 1));
+       if (res)
+               return res;
+
+       res = ds1343_set_reg(dev, DS1343_DATE_REG,
+                               bin2bcd(dt->tm_mday));
+       if (res)
+               return res;
+
+       res = ds1343_set_reg(dev, DS1343_MONTH_REG,
+                               bin2bcd(dt->tm_mon + 1));
+       if (res)
+               return res;
+
+       dt->tm_year %= 100;
+
+       res = ds1343_set_reg(dev, DS1343_YEAR_REG,
+                               bin2bcd(dt->tm_year));
+       if (res)
+               return res;
+
+       return 0;
+}
+
+static int ds1343_update_alarm(struct device *dev)
+{
+       struct ds1343_priv *priv = dev_get_drvdata(dev);
+       struct spi_device *spi = priv->spi;
+       unsigned char control, stat;
+       unsigned char buf[5];
+       int res = 0;
+
+       res = ds1343_get_reg(dev, DS1343_CONTROL_REG, &control);
+       if (res)
+               return res;
+
+       res = ds1343_get_reg(dev, DS1343_STATUS_REG, &stat);
+       if (res)
+               return res;
+
+       control &= ~(DS1343_A0IE);
+       stat &= ~(DS1343_IRQF0);
+
+       res = ds1343_set_reg(dev, DS1343_CONTROL_REG, control);
+       if (res)
+               return res;
+
+       res = ds1343_set_reg(dev, DS1343_STATUS_REG, stat);
+       if (res)
+               return res;
+
+       buf[0] = DS1343_ALM0_SEC_REG | 0x80;
+       buf[1] = priv->alarm_sec < 0 || (priv->irqen & RTC_UF) ?
+               0x80 : bin2bcd(priv->alarm_sec) & 0x7F;
+       buf[2] = priv->alarm_min < 0 || (priv->irqen & RTC_UF) ?
+               0x80 : bin2bcd(priv->alarm_min) & 0x7F;
+       buf[3] = priv->alarm_hour < 0 || (priv->irqen & RTC_UF) ?
+               0x80 : bin2bcd(priv->alarm_hour) & 0x3F;
+       buf[4] = priv->alarm_mday < 0 || (priv->irqen & RTC_UF) ?
+               0x80 : bin2bcd(priv->alarm_mday) & 0x7F;
+
+       res = spi_write_then_read(spi, buf, 5, NULL, 0);
+       if (res)
+               return res;
+
+       if (priv->irqen) {
+               control |= DS1343_A0IE;
+               res = ds1343_set_reg(dev, DS1343_CONTROL_REG, control);
+       }
+
+       return res;
+}
+
+static int ds1343_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+       struct ds1343_priv *priv = dev_get_drvdata(dev);
+       struct spi_device *spi = priv->spi;
+       int res = 0;
+       unsigned char stat;
+
+       if (spi->irq <= 0)
+               return -EINVAL;
+
+       mutex_lock(&priv->mutex);
+
+       res = ds1343_get_reg(dev, DS1343_STATUS_REG, &stat);
+       if (res)
+               goto out;
+
+       alarm->enabled = !!(priv->irqen & RTC_AF);
+       alarm->pending = !!(stat & DS1343_IRQF0);
+
+       alarm->time.tm_sec = priv->alarm_sec < 0 ? 0 : priv->alarm_sec;
+       alarm->time.tm_min = priv->alarm_min < 0 ? 0 : priv->alarm_min;
+       alarm->time.tm_hour = priv->alarm_hour < 0 ? 0 : priv->alarm_hour;
+       alarm->time.tm_mday = priv->alarm_mday < 0 ? 0 : priv->alarm_mday;
+
+       alarm->time.tm_mon = -1;
+       alarm->time.tm_year = -1;
+       alarm->time.tm_wday = -1;
+       alarm->time.tm_yday = -1;
+       alarm->time.tm_isdst = -1;
+
+out:
+       mutex_unlock(&priv->mutex);
+       return res;
+}
+
+static int ds1343_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+       struct ds1343_priv *priv = dev_get_drvdata(dev);
+       struct spi_device *spi = priv->spi;
+       int res = 0;
+
+       if (spi->irq <= 0)
+               return -EINVAL;
+
+       mutex_lock(&priv->mutex);
+
+       priv->alarm_sec = alarm->time.tm_sec;
+       priv->alarm_min = alarm->time.tm_min;
+       priv->alarm_hour = alarm->time.tm_hour;
+       priv->alarm_mday = alarm->time.tm_mday;
+
+       if (alarm->enabled)
+               priv->irqen |= RTC_AF;
+
+       res = ds1343_update_alarm(dev);
+
+       mutex_unlock(&priv->mutex);
+
+       return res;
+}
+
+static int ds1343_alarm_irq_enable(struct device *dev, unsigned int enabled)
+{
+       struct ds1343_priv *priv = dev_get_drvdata(dev);
+       struct spi_device *spi = priv->spi;
+       int res = 0;
+
+       if (spi->irq <= 0)
+               return -EINVAL;
+
+       mutex_lock(&priv->mutex);
+
+       if (enabled)
+               priv->irqen |= RTC_AF;
+       else
+               priv->irqen &= ~RTC_AF;
+
+       res = ds1343_update_alarm(dev);
+
+       mutex_unlock(&priv->mutex);
+
+       return res;
+}
+
+static irqreturn_t ds1343_irq(int irq, void *dev_id)
+{
+       struct ds1343_priv *priv = dev_id;
+
+       disable_irq_nosync(irq);
+       schedule_work(&priv->work);
+       return IRQ_HANDLED;
+}
+
+static void ds1343_work(struct work_struct *work)
+{
+       struct ds1343_priv *priv = container_of(work, struct ds1343_priv, work);
+       struct spi_device *spi = priv->spi;
+       unsigned char stat, control;
+       int res = 0;
+
+       mutex_lock(&priv->mutex);
+
+       res = ds1343_get_reg(&spi->dev, DS1343_STATUS_REG, &stat);
+       if (res)
+               goto out;
+
+       if (stat & DS1343_IRQF0) {
+               stat &= ~DS1343_IRQF0;
+               ds1343_set_reg(&spi->dev, DS1343_STATUS_REG, stat);
+
+               res = ds1343_get_reg(&spi->dev, DS1343_CONTROL_REG, &control);
+               if (res)
+                       goto out;
+
+               control &= ~DS1343_A0IE;
+               ds1343_set_reg(&spi->dev, DS1343_CONTROL_REG, control);
+
+               rtc_update_irq(priv->rtc, 1, RTC_AF | RTC_IRQF);
+       }
+
+out:
+       if (priv->irqen)
+               enable_irq(spi->irq);
+
+       mutex_unlock(&priv->mutex);
+}
+
+static const struct rtc_class_ops ds1343_rtc_ops = {
+       .ioctl          = ds1343_ioctl,
+       .proc           = ds1343_proc,
+       .read_time      = ds1343_read_time,
+       .set_time       = ds1343_set_time,
+       .read_alarm     = ds1343_read_alarm,
+       .set_alarm      = ds1343_set_alarm,
+       .alarm_irq_enable = ds1343_alarm_irq_enable,
+};
+
+static int ds1343_probe(struct spi_device *spi)
+{
+       struct ds1343_priv *priv;
+       unsigned char data;
+       int res;
+
+       priv = devm_kzalloc(&spi->dev, sizeof(struct ds1343_priv), GFP_KERNEL);
+       if (!priv)
+               return -ENOMEM;
+
+       priv->spi = spi;
+       mutex_init(&priv->mutex);
+       INIT_WORK(&priv->work, ds1343_work);
+
+       /* RTC DS1347 works in spi mode 3 and
+        * its chip select is active high
+        */
+       spi->mode = SPI_MODE_3 | SPI_CS_HIGH;
+       spi->bits_per_word = 8;
+       res = spi_setup(spi);
+       if (res)
+               return res;
+
+       spi_set_drvdata(spi, priv);
+
+       res = ds1343_get_reg(&spi->dev, DS1343_SECONDS_REG, &data);
+       if (res)
+               return res;
+
+       ds1343_get_reg(&spi->dev, DS1343_CONTROL_REG, &data);
+       data |= DS1343_INTCN;
+       data &= ~(DS1343_EOSC | DS1343_A1IE | DS1343_A0IE);
+       ds1343_set_reg(&spi->dev, DS1343_CONTROL_REG, data);
+
+       ds1343_get_reg(&spi->dev, DS1343_STATUS_REG, &data);
+       data &= ~(DS1343_OSF | DS1343_IRQF1 | DS1343_IRQF0);
+       ds1343_set_reg(&spi->dev, DS1343_STATUS_REG, data);
+
+       priv->rtc = devm_rtc_device_register(&spi->dev, "ds1343",
+                                       &ds1343_rtc_ops, THIS_MODULE);
+       if (IS_ERR(priv->rtc)) {
+               dev_err(&spi->dev, "unable to register rtc ds1343\n");
+               return PTR_ERR(priv->rtc);
+       }
+
+       if (spi->irq >= 0) {
+               res = devm_request_irq(&spi->dev, spi->irq, ds1343_irq, 0,
+                               "ds1343", priv);
+               if (res) {
+                       dev_err(&spi->dev, "unable to request irq for rtc 
ds1343\n");
+                       return res;
+               }
+
+               device_set_wakeup_capable(&spi->dev, 1);
+       }
+
+       return 0;
+}
+
+static int ds1343_remove(struct spi_device *spi)
+{
+       struct ds1343_priv *priv = spi_get_drvdata(spi);
+
+       if (spi->irq) {
+               mutex_lock(&priv->mutex);
+               priv->irqen &= ~RTC_AF;
+               mutex_unlock(&priv->mutex);
+
+               devm_free_irq(&spi->dev, spi->irq, priv);
+               cancel_work_sync(&priv->work);
+       }
+
+       spi_set_drvdata(spi, NULL);
+
+       return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+
+static int ds1343_suspend(struct device *dev)
+{
+       struct spi_device *spi = to_spi_device(dev);
+
+       if (spi->irq >= 0 && device_may_wakeup(dev))
+               enable_irq_wake(spi->irq);
+
+       return 0;
+}
+
+static int ds1343_resume(struct device *dev)
+{
+       struct spi_device *spi = to_spi_device(dev);
+
+       if (spi->irq >= 0 && device_may_wakeup(dev))
+               disable_irq_wake(spi->irq);
+
+       return 0;
+}
+
+#endif
+
+static SIMPLE_DEV_PM_OPS(ds1343_pm, ds1343_suspend, ds1343_resume);
+
+static struct spi_driver ds1343_driver = {
+       .driver = {
+               .name = "ds1343",
+               .owner = THIS_MODULE,
+               .pm = &ds1343_pm,
+       },
+       .probe = ds1343_probe,
+       .remove = ds1343_remove,
+       .id_table = ds1343_id,
+};
+
+module_spi_driver(ds1343_driver);
+
+MODULE_DESCRIPTION("DS1343 RTC SPI Driver");
+MODULE_AUTHOR("Raghavendra Chandra Ganiga <ravi23gan...@gmail.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION(DS1343_DRV_VERSION);
-- 
1.7.10.4
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