/* * 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>");