rtc: add MOXA ART RTC driver
authorJonas Jensen <jonas.jensen@gmail.com>
Wed, 11 Sep 2013 21:24:17 +0000 (14:24 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 11 Sep 2013 22:58:54 +0000 (15:58 -0700)
Add RTC driver for MOXA ART SoCs.

Signed-off-by: Jonas Jensen <jonas.jensen@gmail.com>
Reviewed-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Documentation/devicetree/bindings/rtc/moxa,moxart-rtc.txt [new file with mode: 0644]
drivers/rtc/Kconfig
drivers/rtc/Makefile
drivers/rtc/rtc-moxart.c [new file with mode: 0644]

diff --git a/Documentation/devicetree/bindings/rtc/moxa,moxart-rtc.txt b/Documentation/devicetree/bindings/rtc/moxa,moxart-rtc.txt
new file mode 100644 (file)
index 0000000..c9d3ac1
--- /dev/null
@@ -0,0 +1,17 @@
+MOXA ART real-time clock
+
+Required properties:
+
+- compatible : Should be "moxa,moxart-rtc"
+- gpio-rtc-sclk : RTC sclk gpio, with zero flags
+- gpio-rtc-data : RTC data gpio, with zero flags
+- gpio-rtc-reset : RTC reset gpio, with zero flags
+
+Example:
+
+       rtc: rtc {
+               compatible = "moxa,moxart-rtc";
+               gpio-rtc-sclk = <&gpio 5 0>;
+               gpio-rtc-data = <&gpio 6 0>;
+               gpio-rtc-reset = <&gpio 7 0>;
+       };
index 9e3498bf302b3ba659f4b89d9a5de7a088af1c15..9654aa3c05cbd87c89b7c7ee2a8d8ebf34d5326e 100644 (file)
@@ -1249,6 +1249,15 @@ config RTC_DRV_SIRFSOC
          Say "yes" here to support the real time clock on SiRF SOC chips.
          This driver can also be built as a module called rtc-sirfsoc.
 
+config RTC_DRV_MOXART
+       tristate "MOXA ART RTC"
+       help
+          If you say yes here you get support for the MOXA ART
+          RTC module.
+
+          This driver can also be built as a module. If so, the module
+          will be called rtc-moxart
+
 comment "HID Sensor RTC drivers"
 
 config RTC_DRV_HID_SENSOR_TIME
index d3b4488f48f2405541d401f750c5894b559b4781..2dff3d2009b5f5a3cad9e30b0eed0e726e9a51e1 100644 (file)
@@ -130,3 +130,4 @@ obj-$(CONFIG_RTC_DRV_WM831X)        += rtc-wm831x.o
 obj-$(CONFIG_RTC_DRV_WM8350)   += rtc-wm8350.o
 obj-$(CONFIG_RTC_DRV_X1205)    += rtc-x1205.o
 obj-$(CONFIG_RTC_DRV_SIRFSOC)  += rtc-sirfsoc.o
+obj-$(CONFIG_RTC_DRV_MOXART)   += rtc-moxart.o
diff --git a/drivers/rtc/rtc-moxart.c b/drivers/rtc/rtc-moxart.c
new file mode 100644 (file)
index 0000000..c29dee0
--- /dev/null
@@ -0,0 +1,330 @@
+/*
+ * MOXA ART RTC driver.
+ *
+ * Copyright (C) 2013 Jonas Jensen
+ *
+ * Jonas Jensen <jonas.jensen@gmail.com>
+ *
+ * Based on code from
+ * Moxa Technology Co., Ltd. <www.moxa.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/rtc.h>
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
+
+#define GPIO_RTC_RESERVED                      0x0C
+#define GPIO_RTC_DATA_SET                      0x10
+#define GPIO_RTC_DATA_CLEAR                    0x14
+#define GPIO_RTC_PIN_PULL_ENABLE               0x18
+#define GPIO_RTC_PIN_PULL_TYPE                 0x1C
+#define GPIO_RTC_INT_ENABLE                    0x20
+#define GPIO_RTC_INT_RAW_STATE                 0x24
+#define GPIO_RTC_INT_MASKED_STATE              0x28
+#define GPIO_RTC_INT_MASK                      0x2C
+#define GPIO_RTC_INT_CLEAR                     0x30
+#define GPIO_RTC_INT_TRIGGER                   0x34
+#define GPIO_RTC_INT_BOTH                      0x38
+#define GPIO_RTC_INT_RISE_NEG                  0x3C
+#define GPIO_RTC_BOUNCE_ENABLE                 0x40
+#define GPIO_RTC_BOUNCE_PRE_SCALE              0x44
+#define GPIO_RTC_PROTECT_W                     0x8E
+#define GPIO_RTC_PROTECT_R                     0x8F
+#define GPIO_RTC_YEAR_W                                0x8C
+#define GPIO_RTC_YEAR_R                                0x8D
+#define GPIO_RTC_DAY_W                         0x8A
+#define GPIO_RTC_DAY_R                         0x8B
+#define GPIO_RTC_MONTH_W                       0x88
+#define GPIO_RTC_MONTH_R                       0x89
+#define GPIO_RTC_DATE_W                                0x86
+#define GPIO_RTC_DATE_R                                0x87
+#define GPIO_RTC_HOURS_W                       0x84
+#define GPIO_RTC_HOURS_R                       0x85
+#define GPIO_RTC_MINUTES_W                     0x82
+#define GPIO_RTC_MINUTES_R                     0x83
+#define GPIO_RTC_SECONDS_W                     0x80
+#define GPIO_RTC_SECONDS_R                     0x81
+#define GPIO_RTC_DELAY_TIME                    8
+
+struct moxart_rtc {
+       struct rtc_device *rtc;
+       spinlock_t rtc_lock;
+       int gpio_data, gpio_sclk, gpio_reset;
+};
+
+static int day_of_year[12] =   { 0, 31, 59, 90, 120, 151, 181,
+                                 212, 243, 273, 304, 334 };
+
+static void moxart_rtc_write_byte(struct device *dev, u8 data)
+{
+       struct moxart_rtc *moxart_rtc = dev_get_drvdata(dev);
+       int i;
+
+       for (i = 0; i < 8; i++, data >>= 1) {
+               gpio_set_value(moxart_rtc->gpio_sclk, 0);
+               gpio_set_value(moxart_rtc->gpio_data, ((data & 1) == 1));
+               udelay(GPIO_RTC_DELAY_TIME);
+               gpio_set_value(moxart_rtc->gpio_sclk, 1);
+               udelay(GPIO_RTC_DELAY_TIME);
+       }
+}
+
+static u8 moxart_rtc_read_byte(struct device *dev)
+{
+       struct moxart_rtc *moxart_rtc = dev_get_drvdata(dev);
+       int i;
+       u8 data = 0;
+
+       for (i = 0; i < 8; i++) {
+               gpio_set_value(moxart_rtc->gpio_sclk, 0);
+               udelay(GPIO_RTC_DELAY_TIME);
+               gpio_set_value(moxart_rtc->gpio_sclk, 1);
+               udelay(GPIO_RTC_DELAY_TIME);
+               if (gpio_get_value(moxart_rtc->gpio_data))
+                       data |= (1 << i);
+               udelay(GPIO_RTC_DELAY_TIME);
+       }
+       return data;
+}
+
+static u8 moxart_rtc_read_register(struct device *dev, u8 cmd)
+{
+       struct moxart_rtc *moxart_rtc = dev_get_drvdata(dev);
+       u8 data;
+       unsigned long flags;
+
+       local_irq_save(flags);
+
+       gpio_direction_output(moxart_rtc->gpio_data, 0);
+       gpio_set_value(moxart_rtc->gpio_reset, 1);
+       udelay(GPIO_RTC_DELAY_TIME);
+       moxart_rtc_write_byte(dev, cmd);
+       gpio_direction_input(moxart_rtc->gpio_data);
+       udelay(GPIO_RTC_DELAY_TIME);
+       data = moxart_rtc_read_byte(dev);
+       gpio_set_value(moxart_rtc->gpio_sclk, 0);
+       gpio_set_value(moxart_rtc->gpio_reset, 0);
+       udelay(GPIO_RTC_DELAY_TIME);
+
+       local_irq_restore(flags);
+
+       return data;
+}
+
+static void moxart_rtc_write_register(struct device *dev, u8 cmd, u8 data)
+{
+       struct moxart_rtc *moxart_rtc = dev_get_drvdata(dev);
+       unsigned long flags;
+
+       local_irq_save(flags);
+
+       gpio_direction_output(moxart_rtc->gpio_data, 0);
+       gpio_set_value(moxart_rtc->gpio_reset, 1);
+       udelay(GPIO_RTC_DELAY_TIME);
+       moxart_rtc_write_byte(dev, cmd);
+       moxart_rtc_write_byte(dev, data);
+       gpio_set_value(moxart_rtc->gpio_sclk, 0);
+       gpio_set_value(moxart_rtc->gpio_reset, 0);
+       udelay(GPIO_RTC_DELAY_TIME);
+
+       local_irq_restore(flags);
+}
+
+static int moxart_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+       struct moxart_rtc *moxart_rtc = dev_get_drvdata(dev);
+
+       spin_lock_irq(&moxart_rtc->rtc_lock);
+
+       moxart_rtc_write_register(dev, GPIO_RTC_PROTECT_W, 0);
+       moxart_rtc_write_register(dev, GPIO_RTC_YEAR_W,
+                                 (((tm->tm_year - 100) / 10) << 4) |
+                                 ((tm->tm_year - 100) % 10));
+
+       moxart_rtc_write_register(dev, GPIO_RTC_MONTH_W,
+                                 (((tm->tm_mon + 1) / 10) << 4) |
+                                 ((tm->tm_mon + 1) % 10));
+
+       moxart_rtc_write_register(dev, GPIO_RTC_DATE_W,
+                                 ((tm->tm_mday / 10) << 4) |
+                                 (tm->tm_mday % 10));
+
+       moxart_rtc_write_register(dev, GPIO_RTC_HOURS_W,
+                                 ((tm->tm_hour / 10) << 4) |
+                                 (tm->tm_hour % 10));
+
+       moxart_rtc_write_register(dev, GPIO_RTC_MINUTES_W,
+                                 ((tm->tm_min / 10) << 4) |
+                                 (tm->tm_min % 10));
+
+       moxart_rtc_write_register(dev, GPIO_RTC_SECONDS_W,
+                                 ((tm->tm_sec / 10) << 4) |
+                                 (tm->tm_sec % 10));
+
+       moxart_rtc_write_register(dev, GPIO_RTC_PROTECT_W, 0x80);
+
+       spin_unlock_irq(&moxart_rtc->rtc_lock);
+
+       dev_dbg(dev, "%s: success tm_year=%d tm_mon=%d\n"
+               "tm_mday=%d tm_hour=%d tm_min=%d tm_sec=%d\n",
+               __func__, tm->tm_year, tm->tm_mon, tm->tm_mday,
+               tm->tm_hour, tm->tm_min, tm->tm_sec);
+
+       return 0;
+}
+
+static int moxart_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+       struct moxart_rtc *moxart_rtc = dev_get_drvdata(dev);
+       unsigned char v;
+
+       spin_lock_irq(&moxart_rtc->rtc_lock);
+
+       v = moxart_rtc_read_register(dev, GPIO_RTC_SECONDS_R);
+       tm->tm_sec = (((v & 0x70) >> 4) * 10) + (v & 0x0F);
+
+       v = moxart_rtc_read_register(dev, GPIO_RTC_MINUTES_R);
+       tm->tm_min = (((v & 0x70) >> 4) * 10) + (v & 0x0F);
+
+       v = moxart_rtc_read_register(dev, GPIO_RTC_HOURS_R);
+       if (v & 0x80) { /* 12-hour mode */
+               tm->tm_hour = (((v & 0x10) >> 4) * 10) + (v & 0x0F);
+               if (v & 0x20) { /* PM mode */
+                       tm->tm_hour += 12;
+                       if (tm->tm_hour >= 24)
+                               tm->tm_hour = 0;
+               }
+       } else { /* 24-hour mode */
+               tm->tm_hour = (((v & 0x30) >> 4) * 10) + (v & 0x0F);
+       }
+
+       v = moxart_rtc_read_register(dev, GPIO_RTC_DATE_R);
+       tm->tm_mday = (((v & 0x30) >> 4) * 10) + (v & 0x0F);
+
+       v = moxart_rtc_read_register(dev, GPIO_RTC_MONTH_R);
+       tm->tm_mon = (((v & 0x10) >> 4) * 10) + (v & 0x0F);
+       tm->tm_mon--;
+
+       v = moxart_rtc_read_register(dev, GPIO_RTC_YEAR_R);
+       tm->tm_year = (((v & 0xF0) >> 4) * 10) + (v & 0x0F);
+       tm->tm_year += 100;
+       if (tm->tm_year <= 69)
+               tm->tm_year += 100;
+
+       v = moxart_rtc_read_register(dev, GPIO_RTC_DAY_R);
+       tm->tm_wday = (v & 0x0f) - 1;
+       tm->tm_yday = day_of_year[tm->tm_mon];
+       tm->tm_yday += (tm->tm_mday - 1);
+       if (tm->tm_mon >= 2) {
+               if (!(tm->tm_year % 4) && (tm->tm_year % 100))
+                       tm->tm_yday++;
+       }
+
+       tm->tm_isdst = 0;
+
+       spin_unlock_irq(&moxart_rtc->rtc_lock);
+
+       return 0;
+}
+
+static const struct rtc_class_ops moxart_rtc_ops = {
+       .read_time      = moxart_rtc_read_time,
+       .set_time       = moxart_rtc_set_time,
+};
+
+static int moxart_rtc_probe(struct platform_device *pdev)
+{
+       struct moxart_rtc *moxart_rtc;
+       int ret = 0;
+
+       moxart_rtc = devm_kzalloc(&pdev->dev, sizeof(*moxart_rtc), GFP_KERNEL);
+       if (!moxart_rtc) {
+               dev_err(&pdev->dev, "devm_kzalloc failed\n");
+               return -ENOMEM;
+       }
+
+       moxart_rtc->gpio_data = of_get_named_gpio(pdev->dev.of_node,
+                                                 "gpio-rtc-data", 0);
+       if (!gpio_is_valid(moxart_rtc->gpio_data)) {
+               dev_err(&pdev->dev, "invalid gpio (data): %d\n",
+                       moxart_rtc->gpio_data);
+               return moxart_rtc->gpio_data;
+       }
+
+       moxart_rtc->gpio_sclk = of_get_named_gpio(pdev->dev.of_node,
+                                                 "gpio-rtc-sclk", 0);
+       if (!gpio_is_valid(moxart_rtc->gpio_sclk)) {
+               dev_err(&pdev->dev, "invalid gpio (sclk): %d\n",
+                       moxart_rtc->gpio_sclk);
+               return moxart_rtc->gpio_sclk;
+       }
+
+       moxart_rtc->gpio_reset = of_get_named_gpio(pdev->dev.of_node,
+                                                  "gpio-rtc-reset", 0);
+       if (!gpio_is_valid(moxart_rtc->gpio_reset)) {
+               dev_err(&pdev->dev, "invalid gpio (reset): %d\n",
+                       moxart_rtc->gpio_reset);
+               return moxart_rtc->gpio_reset;
+       }
+
+       spin_lock_init(&moxart_rtc->rtc_lock);
+       platform_set_drvdata(pdev, moxart_rtc);
+
+       ret = devm_gpio_request(&pdev->dev, moxart_rtc->gpio_data, "rtc_data");
+       if (ret) {
+               dev_err(&pdev->dev, "can't get rtc_data gpio\n");
+               return ret;
+       }
+
+       ret = devm_gpio_request_one(&pdev->dev, moxart_rtc->gpio_sclk,
+                                   GPIOF_DIR_OUT, "rtc_sclk");
+       if (ret) {
+               dev_err(&pdev->dev, "can't get rtc_sclk gpio\n");
+               return ret;
+       }
+
+       ret = devm_gpio_request_one(&pdev->dev, moxart_rtc->gpio_reset,
+                                   GPIOF_DIR_OUT, "rtc_reset");
+       if (ret) {
+               dev_err(&pdev->dev, "can't get rtc_reset gpio\n");
+               return ret;
+       }
+
+       moxart_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
+                                                  &moxart_rtc_ops,
+                                                  THIS_MODULE);
+       if (IS_ERR(moxart_rtc->rtc)) {
+               dev_err(&pdev->dev, "devm_rtc_device_register failed\n");
+               return PTR_ERR(moxart_rtc->rtc);
+       }
+
+       return 0;
+}
+
+static const struct of_device_id moxart_rtc_match[] = {
+       { .compatible = "moxa,moxart-rtc" },
+       { },
+};
+
+static struct platform_driver moxart_rtc_driver = {
+       .probe  = moxart_rtc_probe,
+       .driver = {
+               .name           = "moxart-rtc",
+               .owner          = THIS_MODULE,
+               .of_match_table = moxart_rtc_match,
+       },
+};
+module_platform_driver(moxart_rtc_driver);
+
+MODULE_DESCRIPTION("MOXART RTC driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");