diff options
Diffstat (limited to 'drivers/rtc/rtc-moxart.c')
| -rw-r--r-- | drivers/rtc/rtc-moxart.c | 325 |
1 files changed, 325 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-moxart.c b/drivers/rtc/rtc-moxart.c new file mode 100644 index 000000000..6b24ac9e1 --- /dev/null +++ b/drivers/rtc/rtc-moxart.c @@ -0,0 +1,325 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * 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> + */ + +#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" }, + { }, +}; +MODULE_DEVICE_TABLE(of, moxart_rtc_match); + +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>"); |