diff options
Diffstat (limited to 'drivers/rtc/rtc-r7301.c')
| -rw-r--r-- | drivers/rtc/rtc-r7301.c | 449 |
1 files changed, 449 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-r7301.c b/drivers/rtc/rtc-r7301.c new file mode 100644 index 000000000..5dbaeb7af --- /dev/null +++ b/drivers/rtc/rtc-r7301.c @@ -0,0 +1,449 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * EPSON TOYOCOM RTC-7301SF/DG Driver + * + * Copyright (c) 2016 Akinobu Mita <akinobu.mita@gmail.com> + * + * Based on rtc-rp5c01.c + * + * Datasheet: http://www5.epsondevice.com/en/products/parallel/rtc7301sf.html + */ + +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/delay.h> +#include <linux/regmap.h> +#include <linux/platform_device.h> +#include <linux/rtc.h> + +#define DRV_NAME "rtc-r7301" + +#define RTC7301_1_SEC 0x0 /* Bank 0 and Band 1 */ +#define RTC7301_10_SEC 0x1 /* Bank 0 and Band 1 */ +#define RTC7301_AE BIT(3) +#define RTC7301_1_MIN 0x2 /* Bank 0 and Band 1 */ +#define RTC7301_10_MIN 0x3 /* Bank 0 and Band 1 */ +#define RTC7301_1_HOUR 0x4 /* Bank 0 and Band 1 */ +#define RTC7301_10_HOUR 0x5 /* Bank 0 and Band 1 */ +#define RTC7301_DAY_OF_WEEK 0x6 /* Bank 0 and Band 1 */ +#define RTC7301_1_DAY 0x7 /* Bank 0 and Band 1 */ +#define RTC7301_10_DAY 0x8 /* Bank 0 and Band 1 */ +#define RTC7301_1_MONTH 0x9 /* Bank 0 */ +#define RTC7301_10_MONTH 0xa /* Bank 0 */ +#define RTC7301_1_YEAR 0xb /* Bank 0 */ +#define RTC7301_10_YEAR 0xc /* Bank 0 */ +#define RTC7301_100_YEAR 0xd /* Bank 0 */ +#define RTC7301_1000_YEAR 0xe /* Bank 0 */ +#define RTC7301_ALARM_CONTROL 0xe /* Bank 1 */ +#define RTC7301_ALARM_CONTROL_AIE BIT(0) +#define RTC7301_ALARM_CONTROL_AF BIT(1) +#define RTC7301_TIMER_CONTROL 0xe /* Bank 2 */ +#define RTC7301_TIMER_CONTROL_TIE BIT(0) +#define RTC7301_TIMER_CONTROL_TF BIT(1) +#define RTC7301_CONTROL 0xf /* All banks */ +#define RTC7301_CONTROL_BUSY BIT(0) +#define RTC7301_CONTROL_STOP BIT(1) +#define RTC7301_CONTROL_BANK_SEL_0 BIT(2) +#define RTC7301_CONTROL_BANK_SEL_1 BIT(3) + +struct rtc7301_priv { + struct regmap *regmap; + int irq; + spinlock_t lock; + u8 bank; +}; + +static const struct regmap_config rtc7301_regmap_config = { + .reg_bits = 32, + .val_bits = 8, + .reg_stride = 4, +}; + +static u8 rtc7301_read(struct rtc7301_priv *priv, unsigned int reg) +{ + int reg_stride = regmap_get_reg_stride(priv->regmap); + unsigned int val; + + regmap_read(priv->regmap, reg_stride * reg, &val); + + return val & 0xf; +} + +static void rtc7301_write(struct rtc7301_priv *priv, u8 val, unsigned int reg) +{ + int reg_stride = regmap_get_reg_stride(priv->regmap); + + regmap_write(priv->regmap, reg_stride * reg, val); +} + +static void rtc7301_update_bits(struct rtc7301_priv *priv, unsigned int reg, + u8 mask, u8 val) +{ + int reg_stride = regmap_get_reg_stride(priv->regmap); + + regmap_update_bits(priv->regmap, reg_stride * reg, mask, val); +} + +static int rtc7301_wait_while_busy(struct rtc7301_priv *priv) +{ + int retries = 100; + + while (retries-- > 0) { + u8 val; + + val = rtc7301_read(priv, RTC7301_CONTROL); + if (!(val & RTC7301_CONTROL_BUSY)) + return 0; + + udelay(300); + } + + return -ETIMEDOUT; +} + +static void rtc7301_stop(struct rtc7301_priv *priv) +{ + rtc7301_update_bits(priv, RTC7301_CONTROL, RTC7301_CONTROL_STOP, + RTC7301_CONTROL_STOP); +} + +static void rtc7301_start(struct rtc7301_priv *priv) +{ + rtc7301_update_bits(priv, RTC7301_CONTROL, RTC7301_CONTROL_STOP, 0); +} + +static void rtc7301_select_bank(struct rtc7301_priv *priv, u8 bank) +{ + u8 val = 0; + + if (bank == priv->bank) + return; + + if (bank & BIT(0)) + val |= RTC7301_CONTROL_BANK_SEL_0; + if (bank & BIT(1)) + val |= RTC7301_CONTROL_BANK_SEL_1; + + rtc7301_update_bits(priv, RTC7301_CONTROL, + RTC7301_CONTROL_BANK_SEL_0 | + RTC7301_CONTROL_BANK_SEL_1, val); + + priv->bank = bank; +} + +static void rtc7301_get_time(struct rtc7301_priv *priv, struct rtc_time *tm, + bool alarm) +{ + int year; + + tm->tm_sec = rtc7301_read(priv, RTC7301_1_SEC); + tm->tm_sec += (rtc7301_read(priv, RTC7301_10_SEC) & ~RTC7301_AE) * 10; + tm->tm_min = rtc7301_read(priv, RTC7301_1_MIN); + tm->tm_min += (rtc7301_read(priv, RTC7301_10_MIN) & ~RTC7301_AE) * 10; + tm->tm_hour = rtc7301_read(priv, RTC7301_1_HOUR); + tm->tm_hour += (rtc7301_read(priv, RTC7301_10_HOUR) & ~RTC7301_AE) * 10; + tm->tm_mday = rtc7301_read(priv, RTC7301_1_DAY); + tm->tm_mday += (rtc7301_read(priv, RTC7301_10_DAY) & ~RTC7301_AE) * 10; + + if (alarm) { + tm->tm_wday = -1; + tm->tm_mon = -1; + tm->tm_year = -1; + tm->tm_yday = -1; + tm->tm_isdst = -1; + return; + } + + tm->tm_wday = (rtc7301_read(priv, RTC7301_DAY_OF_WEEK) & ~RTC7301_AE); + tm->tm_mon = rtc7301_read(priv, RTC7301_10_MONTH) * 10 + + rtc7301_read(priv, RTC7301_1_MONTH) - 1; + year = rtc7301_read(priv, RTC7301_1000_YEAR) * 1000 + + rtc7301_read(priv, RTC7301_100_YEAR) * 100 + + rtc7301_read(priv, RTC7301_10_YEAR) * 10 + + rtc7301_read(priv, RTC7301_1_YEAR); + + tm->tm_year = year - 1900; +} + +static void rtc7301_write_time(struct rtc7301_priv *priv, struct rtc_time *tm, + bool alarm) +{ + int year; + + rtc7301_write(priv, tm->tm_sec % 10, RTC7301_1_SEC); + rtc7301_write(priv, tm->tm_sec / 10, RTC7301_10_SEC); + + rtc7301_write(priv, tm->tm_min % 10, RTC7301_1_MIN); + rtc7301_write(priv, tm->tm_min / 10, RTC7301_10_MIN); + + rtc7301_write(priv, tm->tm_hour % 10, RTC7301_1_HOUR); + rtc7301_write(priv, tm->tm_hour / 10, RTC7301_10_HOUR); + + rtc7301_write(priv, tm->tm_mday % 10, RTC7301_1_DAY); + rtc7301_write(priv, tm->tm_mday / 10, RTC7301_10_DAY); + + /* Don't care for alarm register */ + rtc7301_write(priv, alarm ? RTC7301_AE : tm->tm_wday, + RTC7301_DAY_OF_WEEK); + + if (alarm) + return; + + rtc7301_write(priv, (tm->tm_mon + 1) % 10, RTC7301_1_MONTH); + rtc7301_write(priv, (tm->tm_mon + 1) / 10, RTC7301_10_MONTH); + + year = tm->tm_year + 1900; + + rtc7301_write(priv, year % 10, RTC7301_1_YEAR); + rtc7301_write(priv, (year / 10) % 10, RTC7301_10_YEAR); + rtc7301_write(priv, (year / 100) % 10, RTC7301_100_YEAR); + rtc7301_write(priv, year / 1000, RTC7301_1000_YEAR); +} + +static void rtc7301_alarm_irq(struct rtc7301_priv *priv, unsigned int enabled) +{ + rtc7301_update_bits(priv, RTC7301_ALARM_CONTROL, + RTC7301_ALARM_CONTROL_AF | + RTC7301_ALARM_CONTROL_AIE, + enabled ? RTC7301_ALARM_CONTROL_AIE : 0); +} + +static int rtc7301_read_time(struct device *dev, struct rtc_time *tm) +{ + struct rtc7301_priv *priv = dev_get_drvdata(dev); + unsigned long flags; + int err; + + spin_lock_irqsave(&priv->lock, flags); + + rtc7301_select_bank(priv, 0); + + err = rtc7301_wait_while_busy(priv); + if (!err) + rtc7301_get_time(priv, tm, false); + + spin_unlock_irqrestore(&priv->lock, flags); + + return err; +} + +static int rtc7301_set_time(struct device *dev, struct rtc_time *tm) +{ + struct rtc7301_priv *priv = dev_get_drvdata(dev); + unsigned long flags; + + spin_lock_irqsave(&priv->lock, flags); + + rtc7301_stop(priv); + udelay(300); + rtc7301_select_bank(priv, 0); + rtc7301_write_time(priv, tm, false); + rtc7301_start(priv); + + spin_unlock_irqrestore(&priv->lock, flags); + + return 0; +} + +static int rtc7301_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + struct rtc7301_priv *priv = dev_get_drvdata(dev); + unsigned long flags; + u8 alrm_ctrl; + + if (priv->irq <= 0) + return -EINVAL; + + spin_lock_irqsave(&priv->lock, flags); + + rtc7301_select_bank(priv, 1); + rtc7301_get_time(priv, &alarm->time, true); + + alrm_ctrl = rtc7301_read(priv, RTC7301_ALARM_CONTROL); + + alarm->enabled = !!(alrm_ctrl & RTC7301_ALARM_CONTROL_AIE); + alarm->pending = !!(alrm_ctrl & RTC7301_ALARM_CONTROL_AF); + + spin_unlock_irqrestore(&priv->lock, flags); + + return 0; +} + +static int rtc7301_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + struct rtc7301_priv *priv = dev_get_drvdata(dev); + unsigned long flags; + + if (priv->irq <= 0) + return -EINVAL; + + spin_lock_irqsave(&priv->lock, flags); + + rtc7301_select_bank(priv, 1); + rtc7301_write_time(priv, &alarm->time, true); + rtc7301_alarm_irq(priv, alarm->enabled); + + spin_unlock_irqrestore(&priv->lock, flags); + + return 0; +} + +static int rtc7301_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct rtc7301_priv *priv = dev_get_drvdata(dev); + unsigned long flags; + + if (priv->irq <= 0) + return -EINVAL; + + spin_lock_irqsave(&priv->lock, flags); + + rtc7301_select_bank(priv, 1); + rtc7301_alarm_irq(priv, enabled); + + spin_unlock_irqrestore(&priv->lock, flags); + + return 0; +} + +static const struct rtc_class_ops rtc7301_rtc_ops = { + .read_time = rtc7301_read_time, + .set_time = rtc7301_set_time, + .read_alarm = rtc7301_read_alarm, + .set_alarm = rtc7301_set_alarm, + .alarm_irq_enable = rtc7301_alarm_irq_enable, +}; + +static irqreturn_t rtc7301_irq_handler(int irq, void *dev_id) +{ + struct rtc_device *rtc = dev_id; + struct rtc7301_priv *priv = dev_get_drvdata(rtc->dev.parent); + irqreturn_t ret = IRQ_NONE; + u8 alrm_ctrl; + + spin_lock(&priv->lock); + + rtc7301_select_bank(priv, 1); + + alrm_ctrl = rtc7301_read(priv, RTC7301_ALARM_CONTROL); + if (alrm_ctrl & RTC7301_ALARM_CONTROL_AF) { + ret = IRQ_HANDLED; + rtc7301_alarm_irq(priv, false); + rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF); + } + + spin_unlock(&priv->lock); + + return ret; +} + +static void rtc7301_init(struct rtc7301_priv *priv) +{ + unsigned long flags; + + spin_lock_irqsave(&priv->lock, flags); + + rtc7301_select_bank(priv, 2); + rtc7301_write(priv, 0, RTC7301_TIMER_CONTROL); + + spin_unlock_irqrestore(&priv->lock, flags); +} + +static int __init rtc7301_rtc_probe(struct platform_device *dev) +{ + void __iomem *regs; + struct rtc7301_priv *priv; + struct rtc_device *rtc; + int ret; + + priv = devm_kzalloc(&dev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + regs = devm_platform_ioremap_resource(dev, 0); + if (IS_ERR(regs)) + return PTR_ERR(regs); + + priv->regmap = devm_regmap_init_mmio(&dev->dev, regs, + &rtc7301_regmap_config); + if (IS_ERR(priv->regmap)) + return PTR_ERR(priv->regmap); + + priv->irq = platform_get_irq(dev, 0); + + spin_lock_init(&priv->lock); + priv->bank = -1; + + rtc7301_init(priv); + + platform_set_drvdata(dev, priv); + + rtc = devm_rtc_device_register(&dev->dev, DRV_NAME, &rtc7301_rtc_ops, + THIS_MODULE); + if (IS_ERR(rtc)) + return PTR_ERR(rtc); + + if (priv->irq > 0) { + ret = devm_request_irq(&dev->dev, priv->irq, + rtc7301_irq_handler, IRQF_SHARED, + dev_name(&dev->dev), rtc); + if (ret) { + priv->irq = 0; + dev_err(&dev->dev, "unable to request IRQ\n"); + } else { + device_set_wakeup_capable(&dev->dev, true); + } + } + + return 0; +} + +#ifdef CONFIG_PM_SLEEP + +static int rtc7301_suspend(struct device *dev) +{ + struct rtc7301_priv *priv = dev_get_drvdata(dev); + + if (device_may_wakeup(dev)) + enable_irq_wake(priv->irq); + + return 0; +} + +static int rtc7301_resume(struct device *dev) +{ + struct rtc7301_priv *priv = dev_get_drvdata(dev); + + if (device_may_wakeup(dev)) + disable_irq_wake(priv->irq); + + return 0; +} + +#endif + +static SIMPLE_DEV_PM_OPS(rtc7301_pm_ops, rtc7301_suspend, rtc7301_resume); + +static const struct of_device_id rtc7301_dt_match[] = { + { .compatible = "epson,rtc7301sf" }, + { .compatible = "epson,rtc7301dg" }, + {} +}; +MODULE_DEVICE_TABLE(of, rtc7301_dt_match); + +static struct platform_driver rtc7301_rtc_driver = { + .driver = { + .name = DRV_NAME, + .of_match_table = rtc7301_dt_match, + .pm = &rtc7301_pm_ops, + }, +}; + +module_platform_driver_probe(rtc7301_rtc_driver, rtc7301_rtc_probe); + +MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("EPSON TOYOCOM RTC-7301SF/DG Driver"); +MODULE_ALIAS("platform:rtc-r7301"); |