--- /dev/null
+/*
+ * 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)
+ 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",
+ .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>");
Code Review / kvmfornfv.git / blobdiff