--- /dev/null
+// 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->res = platform_get_resource_byname(plat_dev, IORESOURCE_MEM, RTC_REG_NAME);
+ sp_rtc->reg_base = devm_ioremap_resource(&plat_dev->dev, sp_rtc->res);
+ if (IS_ERR(sp_rtc->reg_base))
+ return dev_err_probe(&plat_dev->dev, PTR_ERR(sp_rtc->res),
+ "%s devm_ioremap_resource fail\n", RTC_REG_NAME);
+ dev_dbg(&plat_dev->dev, "res = 0x%x, reg_base = 0x%lx\n",
+ sp_rtc->res->start, (unsigned long)sp_rtc->reg_base);
+
+ sp_rtc->irq = platform_get_irq(plat_dev, 0);
+ if (sp_rtc->irq < 0)
+ return dev_err_probe(&plat_dev->dev, sp_rtc->irq, "platform_get_irq failed\n");
+
+ 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 int 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);
+
+ return 0;
+}
+
+#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 = 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");
+
projects / platform / kernel / linux-starfive.git / commitdiff