linux/drivers/rtc/rtc-puv3.c

287 lines
6.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* RTC driver code specific to PKUnity SoC and UniCore ISA
*
* Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn>
* Copyright (C) 2001-2010 Guan Xuetao
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/clk.h>
#include <linux/log2.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <asm/irq.h>
#include <mach/hardware.h>
static struct resource *puv3_rtc_mem;
static int puv3_rtc_alarmno = IRQ_RTCAlarm;
static int puv3_rtc_tickno = IRQ_RTC;
static DEFINE_SPINLOCK(puv3_rtc_pie_lock);
/* IRQ Handlers */
static irqreturn_t puv3_rtc_alarmirq(int irq, void *id)
{
struct rtc_device *rdev = id;
writel(readl(RTC_RTSR) | RTC_RTSR_AL, RTC_RTSR);
rtc_update_irq(rdev, 1, RTC_AF | RTC_IRQF);
return IRQ_HANDLED;
}
static irqreturn_t puv3_rtc_tickirq(int irq, void *id)
{
struct rtc_device *rdev = id;
writel(readl(RTC_RTSR) | RTC_RTSR_HZ, RTC_RTSR);
rtc_update_irq(rdev, 1, RTC_PF | RTC_IRQF);
return IRQ_HANDLED;
}
/* Update control registers */
static void puv3_rtc_setaie(struct device *dev, int to)
{
unsigned int tmp;
dev_dbg(dev, "%s: aie=%d\n", __func__, to);
tmp = readl(RTC_RTSR) & ~RTC_RTSR_ALE;
if (to)
tmp |= RTC_RTSR_ALE;
writel(tmp, RTC_RTSR);
}
static int puv3_rtc_setpie(struct device *dev, int enabled)
{
unsigned int tmp;
dev_dbg(dev, "%s: pie=%d\n", __func__, enabled);
spin_lock_irq(&puv3_rtc_pie_lock);
tmp = readl(RTC_RTSR) & ~RTC_RTSR_HZE;
if (enabled)
tmp |= RTC_RTSR_HZE;
writel(tmp, RTC_RTSR);
spin_unlock_irq(&puv3_rtc_pie_lock);
return 0;
}
/* Time read/write */
static int puv3_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
{
rtc_time64_to_tm(readl(RTC_RCNR), rtc_tm);
dev_dbg(dev, "read time %ptRr\n", rtc_tm);
return 0;
}
static int puv3_rtc_settime(struct device *dev, struct rtc_time *tm)
{
dev_dbg(dev, "set time %ptRr\n", tm);
writel(rtc_tm_to_time64(tm), RTC_RCNR);
return 0;
}
static int puv3_rtc_getalarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct rtc_time *alm_tm = &alrm->time;
rtc_time64_to_tm(readl(RTC_RTAR), alm_tm);
alrm->enabled = readl(RTC_RTSR) & RTC_RTSR_ALE;
dev_dbg(dev, "read alarm: %d, %ptRr\n", alrm->enabled, alm_tm);
return 0;
}
static int puv3_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct rtc_time *tm = &alrm->time;
dev_dbg(dev, "set alarm: %d, %ptRr\n", alrm->enabled, tm);
writel(rtc_tm_to_time64(tm), RTC_RTAR);
puv3_rtc_setaie(dev, alrm->enabled);
if (alrm->enabled)
enable_irq_wake(puv3_rtc_alarmno);
else
disable_irq_wake(puv3_rtc_alarmno);
return 0;
}
static int puv3_rtc_proc(struct device *dev, struct seq_file *seq)
{
seq_printf(seq, "periodic_IRQ\t: %s\n",
(readl(RTC_RTSR) & RTC_RTSR_HZE) ? "yes" : "no");
return 0;
}
static const struct rtc_class_ops puv3_rtcops = {
.read_time = puv3_rtc_gettime,
.set_time = puv3_rtc_settime,
.read_alarm = puv3_rtc_getalarm,
.set_alarm = puv3_rtc_setalarm,
.proc = puv3_rtc_proc,
};
static void puv3_rtc_enable(struct device *dev, int en)
{
if (!en) {
writel(readl(RTC_RTSR) & ~RTC_RTSR_HZE, RTC_RTSR);
} else {
/* re-enable the device, and check it is ok */
if ((readl(RTC_RTSR) & RTC_RTSR_HZE) == 0) {
dev_info(dev, "rtc disabled, re-enabling\n");
writel(readl(RTC_RTSR) | RTC_RTSR_HZE, RTC_RTSR);
}
}
}
static int puv3_rtc_remove(struct platform_device *dev)
{
puv3_rtc_setpie(&dev->dev, 0);
puv3_rtc_setaie(&dev->dev, 0);
release_resource(puv3_rtc_mem);
kfree(puv3_rtc_mem);
return 0;
}
static int puv3_rtc_probe(struct platform_device *pdev)
{
struct rtc_device *rtc;
struct resource *res;
int ret;
dev_dbg(&pdev->dev, "%s: probe=%p\n", __func__, pdev);
/* find the IRQs */
puv3_rtc_tickno = platform_get_irq(pdev, 1);
if (puv3_rtc_tickno < 0)
return -ENOENT;
puv3_rtc_alarmno = platform_get_irq(pdev, 0);
if (puv3_rtc_alarmno < 0)
return -ENOENT;
dev_dbg(&pdev->dev, "PKUnity_rtc: tick irq %d, alarm irq %d\n",
puv3_rtc_tickno, puv3_rtc_alarmno);
rtc = devm_rtc_allocate_device(&pdev->dev);
if (IS_ERR(rtc))
return PTR_ERR(rtc);
ret = devm_request_irq(&pdev->dev, puv3_rtc_alarmno, puv3_rtc_alarmirq,
0, "pkunity-rtc alarm", rtc);
if (ret) {
dev_err(&pdev->dev, "IRQ%d error %d\n", puv3_rtc_alarmno, ret);
return ret;
}
ret = devm_request_irq(&pdev->dev, puv3_rtc_tickno, puv3_rtc_tickirq,
0, "pkunity-rtc tick", rtc);
if (ret) {
dev_err(&pdev->dev, "IRQ%d error %d\n", puv3_rtc_tickno, ret);
return ret;
}
/* get the memory region */
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (res == NULL) {
dev_err(&pdev->dev, "failed to get memory region resource\n");
return -ENOENT;
}
puv3_rtc_mem = request_mem_region(res->start, resource_size(res),
pdev->name);
if (puv3_rtc_mem == NULL) {
dev_err(&pdev->dev, "failed to reserve memory region\n");
ret = -ENOENT;
goto err_nores;
}
puv3_rtc_enable(&pdev->dev, 1);
/* register RTC and exit */
rtc->ops = &puv3_rtcops;
rtc->range_max = U32_MAX;
ret = rtc_register_device(rtc);
if (ret)
goto err_nortc;
/* platform setup code should have handled this; sigh */
if (!device_can_wakeup(&pdev->dev))
device_init_wakeup(&pdev->dev, 1);
platform_set_drvdata(pdev, rtc);
return 0;
err_nortc:
puv3_rtc_enable(&pdev->dev, 0);
release_resource(puv3_rtc_mem);
err_nores:
return ret;
}
#ifdef CONFIG_PM_SLEEP
static int ticnt_save;
static int puv3_rtc_suspend(struct device *dev)
{
/* save RTAR for anyone using periodic interrupts */
ticnt_save = readl(RTC_RTAR);
puv3_rtc_enable(dev, 0);
return 0;
}
static int puv3_rtc_resume(struct device *dev)
{
puv3_rtc_enable(dev, 1);
writel(ticnt_save, RTC_RTAR);
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(puv3_rtc_pm_ops, puv3_rtc_suspend, puv3_rtc_resume);
static struct platform_driver puv3_rtc_driver = {
.probe = puv3_rtc_probe,
.remove = puv3_rtc_remove,
.driver = {
.name = "PKUnity-v3-RTC",
.pm = &puv3_rtc_pm_ops,
}
};
module_platform_driver(puv3_rtc_driver);
MODULE_DESCRIPTION("RTC Driver for the PKUnity v3 chip");
MODULE_AUTHOR("Hu Dongliang");
MODULE_LICENSE("GPL v2");