diff options
Diffstat (limited to 'drivers/rtc/rtc-sunplus.c')
| -rw-r--r-- | drivers/rtc/rtc-sunplus.c | 359 |
1 files changed, 359 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-sunplus.c b/drivers/rtc/rtc-sunplus.c new file mode 100644 index 0000000000..20c7e97c2f --- /dev/null +++ b/drivers/rtc/rtc-sunplus.c @@ -0,0 +1,359 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * The RTC driver for Sunplus SP7021 + * + * Copyright (C) 2019 Sunplus Technology Inc., All rights reseerved. + */ + +#include <linux/bitfield.h> +#include <linux/clk.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/ktime.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/reset.h> +#include <linux/rtc.h> + +#define RTC_REG_NAME "rtc" + +#define RTC_CTRL 0x40 +#define TIMER_FREEZE_MASK_BIT BIT(5 + 16) +#define TIMER_FREEZE BIT(5) +#define DIS_SYS_RST_RTC_MASK_BIT BIT(4 + 16) +#define DIS_SYS_RST_RTC BIT(4) +#define RTC32K_MODE_RESET_MASK_BIT BIT(3 + 16) +#define RTC32K_MODE_RESET BIT(3) +#define ALARM_EN_OVERDUE_MASK_BIT BIT(2 + 16) +#define ALARM_EN_OVERDUE BIT(2) +#define ALARM_EN_PMC_MASK_BIT BIT(1 + 16) +#define ALARM_EN_PMC BIT(1) +#define ALARM_EN_MASK_BIT BIT(0 + 16) +#define ALARM_EN BIT(0) +#define RTC_TIMER_OUT 0x44 +#define RTC_DIVIDER 0x48 +#define RTC_TIMER_SET 0x4c +#define RTC_ALARM_SET 0x50 +#define RTC_USER_DATA 0x54 +#define RTC_RESET_RECORD 0x58 +#define RTC_BATT_CHARGE_CTRL 0x5c +#define BAT_CHARGE_RSEL_MASK_BIT GENMASK(3 + 16, 2 + 16) +#define BAT_CHARGE_RSEL_MASK GENMASK(3, 2) +#define BAT_CHARGE_RSEL_2K_OHM FIELD_PREP(BAT_CHARGE_RSEL_MASK, 0) +#define BAT_CHARGE_RSEL_250_OHM FIELD_PREP(BAT_CHARGE_RSEL_MASK, 1) +#define BAT_CHARGE_RSEL_50_OHM FIELD_PREP(BAT_CHARGE_RSEL_MASK, 2) +#define BAT_CHARGE_RSEL_0_OHM FIELD_PREP(BAT_CHARGE_RSEL_MASK, 3) +#define BAT_CHARGE_DSEL_MASK_BIT BIT(1 + 16) +#define BAT_CHARGE_DSEL_MASK GENMASK(1, 1) +#define BAT_CHARGE_DSEL_ON FIELD_PREP(BAT_CHARGE_DSEL_MASK, 0) +#define BAT_CHARGE_DSEL_OFF FIELD_PREP(BAT_CHARGE_DSEL_MASK, 1) +#define BAT_CHARGE_EN_MASK_BIT BIT(0 + 16) +#define BAT_CHARGE_EN BIT(0) +#define RTC_TRIM_CTRL 0x60 + +struct sunplus_rtc { + struct rtc_device *rtc; + struct resource *res; + struct clk *rtcclk; + struct reset_control *rstc; + void __iomem *reg_base; + int irq; +}; + +static void sp_get_seconds(struct device *dev, unsigned long *secs) +{ + struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev); + + *secs = (unsigned long)readl(sp_rtc->reg_base + RTC_TIMER_OUT); +} + +static void sp_set_seconds(struct device *dev, unsigned long secs) +{ + struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev); + + writel((u32)secs, sp_rtc->reg_base + RTC_TIMER_SET); +} + +static int sp_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + unsigned long secs; + + sp_get_seconds(dev, &secs); + rtc_time64_to_tm(secs, tm); + + return 0; +} + +static int sp_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + unsigned long secs; + + secs = rtc_tm_to_time64(tm); + dev_dbg(dev, "%s, secs = %lu\n", __func__, secs); + sp_set_seconds(dev, secs); + + return 0; +} + +static int sp_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev); + unsigned long alarm_time; + + alarm_time = rtc_tm_to_time64(&alrm->time); + dev_dbg(dev, "%s, alarm_time: %u\n", __func__, (u32)(alarm_time)); + writel((u32)alarm_time, sp_rtc->reg_base + RTC_ALARM_SET); + + return 0; +} + +static int sp_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev); + unsigned int alarm_time; + + alarm_time = readl(sp_rtc->reg_base + RTC_ALARM_SET); + dev_dbg(dev, "%s, alarm_time: %u\n", __func__, alarm_time); + + if (alarm_time == 0) + alrm->enabled = 0; + else + alrm->enabled = 1; + + rtc_time64_to_tm((unsigned long)(alarm_time), &alrm->time); + + return 0; +} + +static int sp_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev); + + if (enabled) + writel((TIMER_FREEZE_MASK_BIT | DIS_SYS_RST_RTC_MASK_BIT | + RTC32K_MODE_RESET_MASK_BIT | ALARM_EN_OVERDUE_MASK_BIT | + ALARM_EN_PMC_MASK_BIT | ALARM_EN_MASK_BIT) | + (DIS_SYS_RST_RTC | ALARM_EN_OVERDUE | ALARM_EN_PMC | ALARM_EN), + sp_rtc->reg_base + RTC_CTRL); + else + writel((ALARM_EN_OVERDUE_MASK_BIT | ALARM_EN_PMC_MASK_BIT | ALARM_EN_MASK_BIT) | + 0x0, sp_rtc->reg_base + RTC_CTRL); + + return 0; +} + +static const struct rtc_class_ops sp_rtc_ops = { + .read_time = sp_rtc_read_time, + .set_time = sp_rtc_set_time, + .set_alarm = sp_rtc_set_alarm, + .read_alarm = sp_rtc_read_alarm, + .alarm_irq_enable = sp_rtc_alarm_irq_enable, +}; + +static irqreturn_t sp_rtc_irq_handler(int irq, void *dev_id) +{ + struct platform_device *plat_dev = dev_id; + struct sunplus_rtc *sp_rtc = dev_get_drvdata(&plat_dev->dev); + + rtc_update_irq(sp_rtc->rtc, 1, RTC_IRQF | RTC_AF); + dev_dbg(&plat_dev->dev, "[RTC] ALARM INT\n"); + + return IRQ_HANDLED; +} + +/* + * ------------------------------------------------------------------------------------- + * bat_charge_rsel bat_charge_dsel bat_charge_en Remarks + * x x 0 Disable + * 0 0 1 0.86mA (2K Ohm with diode) + * 1 0 1 1.81mA (250 Ohm with diode) + * 2 0 1 2.07mA (50 Ohm with diode) + * 3 0 1 16.0mA (0 Ohm with diode) + * 0 1 1 1.36mA (2K Ohm without diode) + * 1 1 1 3.99mA (250 Ohm without diode) + * 2 1 1 4.41mA (50 Ohm without diode) + * 3 1 1 16.0mA (0 Ohm without diode) + * ------------------------------------------------------------------------------------- + */ +static void sp_rtc_set_trickle_charger(struct device dev) +{ + struct sunplus_rtc *sp_rtc = dev_get_drvdata(&dev); + u32 ohms, rsel; + u32 chargeable; + + if (of_property_read_u32(dev.of_node, "trickle-resistor-ohms", &ohms) || + of_property_read_u32(dev.of_node, "aux-voltage-chargeable", &chargeable)) { + dev_warn(&dev, "battery charger disabled\n"); + return; + } + + switch (ohms) { + case 2000: + rsel = BAT_CHARGE_RSEL_2K_OHM; + break; + case 250: + rsel = BAT_CHARGE_RSEL_250_OHM; + break; + case 50: + rsel = BAT_CHARGE_RSEL_50_OHM; + break; + case 0: + rsel = BAT_CHARGE_RSEL_0_OHM; + break; + default: + dev_err(&dev, "invalid charger resistor value (%d)\n", ohms); + return; + } + + writel(BAT_CHARGE_RSEL_MASK_BIT | rsel, sp_rtc->reg_base + RTC_BATT_CHARGE_CTRL); + + switch (chargeable) { + case 0: + writel(BAT_CHARGE_DSEL_MASK_BIT | BAT_CHARGE_DSEL_OFF, + sp_rtc->reg_base + RTC_BATT_CHARGE_CTRL); + break; + case 1: + writel(BAT_CHARGE_DSEL_MASK_BIT | BAT_CHARGE_DSEL_ON, + sp_rtc->reg_base + RTC_BATT_CHARGE_CTRL); + break; + default: + dev_err(&dev, "invalid aux-voltage-chargeable value (%d)\n", chargeable); + return; + } + + writel(BAT_CHARGE_EN_MASK_BIT | BAT_CHARGE_EN, sp_rtc->reg_base + RTC_BATT_CHARGE_CTRL); +} + +static int sp_rtc_probe(struct platform_device *plat_dev) +{ + struct sunplus_rtc *sp_rtc; + int ret; + + sp_rtc = devm_kzalloc(&plat_dev->dev, sizeof(*sp_rtc), GFP_KERNEL); + if (!sp_rtc) + return -ENOMEM; + + sp_rtc->reg_base = devm_platform_ioremap_resource_byname(plat_dev, RTC_REG_NAME); + if (IS_ERR(sp_rtc->reg_base)) + return dev_err_probe(&plat_dev->dev, PTR_ERR(sp_rtc->reg_base), + "%s devm_ioremap_resource fail\n", RTC_REG_NAME); + dev_dbg(&plat_dev->dev, "res = %pR, reg_base = %p\n", + sp_rtc->res, sp_rtc->reg_base); + + sp_rtc->irq = platform_get_irq(plat_dev, 0); + if (sp_rtc->irq < 0) + return sp_rtc->irq; + + ret = devm_request_irq(&plat_dev->dev, sp_rtc->irq, sp_rtc_irq_handler, + IRQF_TRIGGER_RISING, "rtc irq", plat_dev); + if (ret) + return dev_err_probe(&plat_dev->dev, ret, "devm_request_irq failed:\n"); + + sp_rtc->rtcclk = devm_clk_get(&plat_dev->dev, NULL); + if (IS_ERR(sp_rtc->rtcclk)) + return dev_err_probe(&plat_dev->dev, PTR_ERR(sp_rtc->rtcclk), + "devm_clk_get fail\n"); + + sp_rtc->rstc = devm_reset_control_get_exclusive(&plat_dev->dev, NULL); + if (IS_ERR(sp_rtc->rstc)) + return dev_err_probe(&plat_dev->dev, PTR_ERR(sp_rtc->rstc), + "failed to retrieve reset controller\n"); + + ret = clk_prepare_enable(sp_rtc->rtcclk); + if (ret) + goto free_clk; + + ret = reset_control_deassert(sp_rtc->rstc); + if (ret) + goto free_reset_assert; + + device_init_wakeup(&plat_dev->dev, 1); + dev_set_drvdata(&plat_dev->dev, sp_rtc); + + sp_rtc->rtc = devm_rtc_allocate_device(&plat_dev->dev); + if (IS_ERR(sp_rtc->rtc)) { + ret = PTR_ERR(sp_rtc->rtc); + goto free_reset_assert; + } + + sp_rtc->rtc->range_max = U32_MAX; + sp_rtc->rtc->range_min = 0; + sp_rtc->rtc->ops = &sp_rtc_ops; + + ret = devm_rtc_register_device(sp_rtc->rtc); + if (ret) + goto free_reset_assert; + + /* Setup trickle charger */ + if (plat_dev->dev.of_node) + sp_rtc_set_trickle_charger(plat_dev->dev); + + /* Keep RTC from system reset */ + writel(DIS_SYS_RST_RTC_MASK_BIT | DIS_SYS_RST_RTC, sp_rtc->reg_base + RTC_CTRL); + + return 0; + +free_reset_assert: + reset_control_assert(sp_rtc->rstc); +free_clk: + clk_disable_unprepare(sp_rtc->rtcclk); + + return ret; +} + +static void sp_rtc_remove(struct platform_device *plat_dev) +{ + struct sunplus_rtc *sp_rtc = dev_get_drvdata(&plat_dev->dev); + + device_init_wakeup(&plat_dev->dev, 0); + reset_control_assert(sp_rtc->rstc); + clk_disable_unprepare(sp_rtc->rtcclk); +} + +#ifdef CONFIG_PM_SLEEP +static int sp_rtc_suspend(struct device *dev) +{ + struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev); + + if (device_may_wakeup(dev)) + enable_irq_wake(sp_rtc->irq); + + return 0; +} + +static int sp_rtc_resume(struct device *dev) +{ + struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev); + + if (device_may_wakeup(dev)) + disable_irq_wake(sp_rtc->irq); + + return 0; +} +#endif + +static const struct of_device_id sp_rtc_of_match[] = { + { .compatible = "sunplus,sp7021-rtc" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, sp_rtc_of_match); + +static SIMPLE_DEV_PM_OPS(sp_rtc_pm_ops, sp_rtc_suspend, sp_rtc_resume); + +static struct platform_driver sp_rtc_driver = { + .probe = sp_rtc_probe, + .remove_new = sp_rtc_remove, + .driver = { + .name = "sp7021-rtc", + .of_match_table = sp_rtc_of_match, + .pm = &sp_rtc_pm_ops, + }, +}; +module_platform_driver(sp_rtc_driver); + +MODULE_AUTHOR("Vincent Shih <vincent.sunplus@gmail.com>"); +MODULE_DESCRIPTION("Sunplus RTC driver"); +MODULE_LICENSE("GPL v2"); + |