rtc: Add driver for RTC in Sunplus SP7021 (fad6cbe9) · Commits · EulixOS / Software / Kernel

MAINTAINERS

+6 −0

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		@@ -18216,6 +18216,12 @@ L: netdev@vger.kernel.org
		S: Maintained
		F: drivers/net/ethernet/dlink/sundance.c

		SUNPLUS RTC DRIVER
		M: Vincent Shih <vincent.sunplus@gmail.com>
		L: linux-rtc@vger.kernel.org
		S: Maintained
		F: drivers/rtc/rtc-sunplus.c

		SUPERH
		M: Yoshinori Sato <ysato@users.sourceforge.jp>
		M: Rich Felker <dalias@libc.org>

drivers/rtc/Kconfig

+13 −0

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		@@ -1455,6 +1455,19 @@ config RTC_DRV_SH
		To compile this driver as a module, choose M here: the
		module will be called rtc-sh.

		config RTC_DRV_SUNPLUS
		tristate "Sunplus SP7021 RTC"
		depends on SOC_SP7021
		help
		Say 'yes' to get support for the real-time clock present in
		Sunplus SP7021 - a SoC for industrial applications. It provides
		RTC status check, timer/alarm functionalities, user data
		reservation with the battery over 2.5V, RTC power status check
		and battery charge.

		This driver can also be built as a module. If so, the module
		will be called rtc-sunplus.

		config RTC_DRV_VR41XX
		tristate "NEC VR41XX"
		depends on CPU_VR41XX \|\| COMPILE_TEST

drivers/rtc/Makefile

+1 −0

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		@@ -166,6 +166,7 @@ obj-$(CONFIG_RTC_DRV_STM32) += rtc-stm32.o
		obj-$(CONFIG_RTC_DRV_STMP) += rtc-stmp3xxx.o
		obj-$(CONFIG_RTC_DRV_SUN4V) += rtc-sun4v.o
		obj-$(CONFIG_RTC_DRV_SUN6I) += rtc-sun6i.o
		obj-$(CONFIG_RTC_DRV_SUNPLUS) += rtc-sunplus.o
		obj-$(CONFIG_RTC_DRV_SUNXI) += rtc-sunxi.o
		obj-$(CONFIG_RTC_DRV_TEGRA) += rtc-tegra.o
		obj-$(CONFIG_RTC_DRV_TEST) += rtc-test.o

drivers/rtc/rtc-sunplus.c

0 → 100644

+362 −0

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		// 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");