// 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");