blob: d417b203cbc553eb25ab0cbf0eb493bcd84c9d46 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* SuperH On-Chip RTC Support
*
* Copyright (C) 2006 - 2009 Paul Mundt
* Copyright (C) 2006 Jamie Lenehan
* Copyright (C) 2008 Angelo Castello
*
* Based on the old arch/sh/kernel/cpu/rtc.c by:
*
* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
* Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
*/
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/kernel.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/seq_file.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/log2.h>
#include <linux/clk.h>
#include <linux/slab.h>
#ifdef CONFIG_SUPERH
#include <asm/rtc.h>
#else
/* Default values for RZ/A RTC */
#define rtc_reg_size sizeof(u16)
#define RTC_BIT_INVERTED 0 /* no chip bugs */
#define RTC_CAP_4_DIGIT_YEAR (1 << 0)
#define RTC_DEF_CAPABILITIES RTC_CAP_4_DIGIT_YEAR
#endif
#define DRV_NAME "sh-rtc"
#define RTC_REG(r) ((r) * rtc_reg_size)
#define R64CNT RTC_REG(0)
#define RSECCNT RTC_REG(1) /* RTC sec */
#define RMINCNT RTC_REG(2) /* RTC min */
#define RHRCNT RTC_REG(3) /* RTC hour */
#define RWKCNT RTC_REG(4) /* RTC week */
#define RDAYCNT RTC_REG(5) /* RTC day */
#define RMONCNT RTC_REG(6) /* RTC month */
#define RYRCNT RTC_REG(7) /* RTC year */
#define RSECAR RTC_REG(8) /* ALARM sec */
#define RMINAR RTC_REG(9) /* ALARM min */
#define RHRAR RTC_REG(10) /* ALARM hour */
#define RWKAR RTC_REG(11) /* ALARM week */
#define RDAYAR RTC_REG(12) /* ALARM day */
#define RMONAR RTC_REG(13) /* ALARM month */
#define RCR1 RTC_REG(14) /* Control */
#define RCR2 RTC_REG(15) /* Control */
/*
* Note on RYRAR and RCR3: Up until this point most of the register
* definitions are consistent across all of the available parts. However,
* the placement of the optional RYRAR and RCR3 (the RYRAR control
* register used to control RYRCNT/RYRAR compare) varies considerably
* across various parts, occasionally being mapped in to a completely
* unrelated address space. For proper RYRAR support a separate resource
* would have to be handed off, but as this is purely optional in
* practice, we simply opt not to support it, thereby keeping the code
* quite a bit more simplified.
*/
/* ALARM Bits - or with BCD encoded value */
#define AR_ENB 0x80 /* Enable for alarm cmp */
/* Period Bits */
#define PF_HP 0x100 /* Enable Half Period to support 8,32,128Hz */
#define PF_COUNT 0x200 /* Half periodic counter */
#define PF_OXS 0x400 /* Periodic One x Second */
#define PF_KOU 0x800 /* Kernel or User periodic request 1=kernel */
#define PF_MASK 0xf00
/* RCR1 Bits */
#define RCR1_CF 0x80 /* Carry Flag */
#define RCR1_CIE 0x10 /* Carry Interrupt Enable */
#define RCR1_AIE 0x08 /* Alarm Interrupt Enable */
#define RCR1_AF 0x01 /* Alarm Flag */
/* RCR2 Bits */
#define RCR2_PEF 0x80 /* PEriodic interrupt Flag */
#define RCR2_PESMASK 0x70 /* Periodic interrupt Set */
#define RCR2_RTCEN 0x08 /* ENable RTC */
#define RCR2_ADJ 0x04 /* ADJustment (30-second) */
#define RCR2_RESET 0x02 /* Reset bit */
#define RCR2_START 0x01 /* Start bit */
struct sh_rtc {
void __iomem *regbase;
unsigned long regsize;
struct resource *res;
int alarm_irq;
int periodic_irq;
int carry_irq;
struct clk *clk;
struct rtc_device *rtc_dev;
spinlock_t lock;
unsigned long capabilities; /* See asm/rtc.h for cap bits */
unsigned short periodic_freq;
};
static int __sh_rtc_interrupt(struct sh_rtc *rtc)
{
unsigned int tmp, pending;
tmp = readb(rtc->regbase + RCR1);
pending = tmp & RCR1_CF;
tmp &= ~RCR1_CF;
writeb(tmp, rtc->regbase + RCR1);
/* Users have requested One x Second IRQ */
if (pending && rtc->periodic_freq & PF_OXS)
rtc_update_irq(rtc->rtc_dev, 1, RTC_UF | RTC_IRQF);
return pending;
}
static int __sh_rtc_alarm(struct sh_rtc *rtc)
{
unsigned int tmp, pending;
tmp = readb(rtc->regbase + RCR1);
pending = tmp & RCR1_AF;
tmp &= ~(RCR1_AF | RCR1_AIE);
writeb(tmp, rtc->regbase + RCR1);
if (pending)
rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF);
return pending;
}
static int __sh_rtc_periodic(struct sh_rtc *rtc)
{
unsigned int tmp, pending;
tmp = readb(rtc->regbase + RCR2);
pending = tmp & RCR2_PEF;
tmp &= ~RCR2_PEF;
writeb(tmp, rtc->regbase + RCR2);
if (!pending)
return 0;
/* Half period enabled than one skipped and the next notified */
if ((rtc->periodic_freq & PF_HP) && (rtc->periodic_freq & PF_COUNT))
rtc->periodic_freq &= ~PF_COUNT;
else {
if (rtc->periodic_freq & PF_HP)
rtc->periodic_freq |= PF_COUNT;
rtc_update_irq(rtc->rtc_dev, 1, RTC_PF | RTC_IRQF);
}
return pending;
}
static irqreturn_t sh_rtc_interrupt(int irq, void *dev_id)
{
struct sh_rtc *rtc = dev_id;
int ret;
spin_lock(&rtc->lock);
ret = __sh_rtc_interrupt(rtc);
spin_unlock(&rtc->lock);
return IRQ_RETVAL(ret);
}
static irqreturn_t sh_rtc_alarm(int irq, void *dev_id)
{
struct sh_rtc *rtc = dev_id;
int ret;
spin_lock(&rtc->lock);
ret = __sh_rtc_alarm(rtc);
spin_unlock(&rtc->lock);
return IRQ_RETVAL(ret);
}
static irqreturn_t sh_rtc_periodic(int irq, void *dev_id)
{
struct sh_rtc *rtc = dev_id;
int ret;
spin_lock(&rtc->lock);
ret = __sh_rtc_periodic(rtc);
spin_unlock(&rtc->lock);
return IRQ_RETVAL(ret);
}
static irqreturn_t sh_rtc_shared(int irq, void *dev_id)
{
struct sh_rtc *rtc = dev_id;
int ret;
spin_lock(&rtc->lock);
ret = __sh_rtc_interrupt(rtc);
ret |= __sh_rtc_alarm(rtc);
ret |= __sh_rtc_periodic(rtc);
spin_unlock(&rtc->lock);
return IRQ_RETVAL(ret);
}
static inline void sh_rtc_setaie(struct device *dev, unsigned int enable)
{
struct sh_rtc *rtc = dev_get_drvdata(dev);
unsigned int tmp;
spin_lock_irq(&rtc->lock);
tmp = readb(rtc->regbase + RCR1);
if (enable)
tmp |= RCR1_AIE;
else
tmp &= ~RCR1_AIE;
writeb(tmp, rtc->regbase + RCR1);
spin_unlock_irq(&rtc->lock);
}
static int sh_rtc_proc(struct device *dev, struct seq_file *seq)
{
struct sh_rtc *rtc = dev_get_drvdata(dev);
unsigned int tmp;
tmp = readb(rtc->regbase + RCR1);
seq_printf(seq, "carry_IRQ\t: %s\n", (tmp & RCR1_CIE) ? "yes" : "no");
tmp = readb(rtc->regbase + RCR2);
seq_printf(seq, "periodic_IRQ\t: %s\n",
(tmp & RCR2_PESMASK) ? "yes" : "no");
return 0;
}
static inline void sh_rtc_setcie(struct device *dev, unsigned int enable)
{
struct sh_rtc *rtc = dev_get_drvdata(dev);
unsigned int tmp;
spin_lock_irq(&rtc->lock);
tmp = readb(rtc->regbase + RCR1);
if (!enable)
tmp &= ~RCR1_CIE;
else
tmp |= RCR1_CIE;
writeb(tmp, rtc->regbase + RCR1);
spin_unlock_irq(&rtc->lock);
}
static int sh_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
sh_rtc_setaie(dev, enabled);
return 0;
}
static int sh_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct sh_rtc *rtc = dev_get_drvdata(dev);
unsigned int sec128, sec2, yr, yr100, cf_bit;
do {
unsigned int tmp;
spin_lock_irq(&rtc->lock);
tmp = readb(rtc->regbase + RCR1);
tmp &= ~RCR1_CF; /* Clear CF-bit */
tmp |= RCR1_CIE;
writeb(tmp, rtc->regbase + RCR1);
sec128 = readb(rtc->regbase + R64CNT);
tm->tm_sec = bcd2bin(readb(rtc->regbase + RSECCNT));
tm->tm_min = bcd2bin(readb(rtc->regbase + RMINCNT));
tm->tm_hour = bcd2bin(readb(rtc->regbase + RHRCNT));
tm->tm_wday = bcd2bin(readb(rtc->regbase + RWKCNT));
tm->tm_mday = bcd2bin(readb(rtc->regbase + RDAYCNT));
tm->tm_mon = bcd2bin(readb(rtc->regbase + RMONCNT)) - 1;
if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
yr = readw(rtc->regbase + RYRCNT);
yr100 = bcd2bin(yr >> 8);
yr &= 0xff;
} else {
yr = readb(rtc->regbase + RYRCNT);
yr100 = bcd2bin((yr == 0x99) ? 0x19 : 0x20);
}
tm->tm_year = (yr100 * 100 + bcd2bin(yr)) - 1900;
sec2 = readb(rtc->regbase + R64CNT);
cf_bit = readb(rtc->regbase + RCR1) & RCR1_CF;
spin_unlock_irq(&rtc->lock);
} while (cf_bit != 0 || ((sec128 ^ sec2) & RTC_BIT_INVERTED) != 0);
#if RTC_BIT_INVERTED != 0
if ((sec128 & RTC_BIT_INVERTED))
tm->tm_sec--;
#endif
/* only keep the carry interrupt enabled if UIE is on */
if (!(rtc->periodic_freq & PF_OXS))
sh_rtc_setcie(dev, 0);
dev_dbg(dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
"mday=%d, mon=%d, year=%d, wday=%d\n",
__func__,
tm->tm_sec, tm->tm_min, tm->tm_hour,
tm->tm_mday, tm->tm_mon + 1, tm->tm_year, tm->tm_wday);
return 0;
}
static int sh_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct sh_rtc *rtc = dev_get_drvdata(dev);
unsigned int tmp;
int year;
spin_lock_irq(&rtc->lock);
/* Reset pre-scaler & stop RTC */
tmp = readb(rtc->regbase + RCR2);
tmp |= RCR2_RESET;
tmp &= ~RCR2_START;
writeb(tmp, rtc->regbase + RCR2);
writeb(bin2bcd(tm->tm_sec), rtc->regbase + RSECCNT);
writeb(bin2bcd(tm->tm_min), rtc->regbase + RMINCNT);
writeb(bin2bcd(tm->tm_hour), rtc->regbase + RHRCNT);
writeb(bin2bcd(tm->tm_wday), rtc->regbase + RWKCNT);
writeb(bin2bcd(tm->tm_mday), rtc->regbase + RDAYCNT);
writeb(bin2bcd(tm->tm_mon + 1), rtc->regbase + RMONCNT);
if (rtc->capabilities & RTC_CAP_4_DIGIT_YEAR) {
year = (bin2bcd((tm->tm_year + 1900) / 100) << 8) |
bin2bcd(tm->tm_year % 100);
writew(year, rtc->regbase + RYRCNT);
} else {
year = tm->tm_year % 100;
writeb(bin2bcd(year), rtc->regbase + RYRCNT);
}
/* Start RTC */
tmp = readb(rtc->regbase + RCR2);
tmp &= ~RCR2_RESET;
tmp |= RCR2_RTCEN | RCR2_START;
writeb(tmp, rtc->regbase + RCR2);
spin_unlock_irq(&rtc->lock);
return 0;
}
static inline int sh_rtc_read_alarm_value(struct sh_rtc *rtc, int reg_off)
{
unsigned int byte;
int value = 0xff; /* return 0xff for ignored values */
byte = readb(rtc->regbase + reg_off);
if (byte & AR_ENB) {
byte &= ~AR_ENB; /* strip the enable bit */
value = bcd2bin(byte);
}
return value;
}
static int sh_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
{
struct sh_rtc *rtc = dev_get_drvdata(dev);
struct rtc_time *tm = &wkalrm->time;
spin_lock_irq(&rtc->lock);
tm->tm_sec = sh_rtc_read_alarm_value(rtc, RSECAR);
tm->tm_min = sh_rtc_read_alarm_value(rtc, RMINAR);
tm->tm_hour = sh_rtc_read_alarm_value(rtc, RHRAR);
tm->tm_wday = sh_rtc_read_alarm_value(rtc, RWKAR);
tm->tm_mday = sh_rtc_read_alarm_value(rtc, RDAYAR);
tm->tm_mon = sh_rtc_read_alarm_value(rtc, RMONAR);
if (tm->tm_mon > 0)
tm->tm_mon -= 1; /* RTC is 1-12, tm_mon is 0-11 */
wkalrm->enabled = (readb(rtc->regbase + RCR1) & RCR1_AIE) ? 1 : 0;
spin_unlock_irq(&rtc->lock);
return 0;
}
static inline void sh_rtc_write_alarm_value(struct sh_rtc *rtc,
int value, int reg_off)
{
/* < 0 for a value that is ignored */
if (value < 0)
writeb(0, rtc->regbase + reg_off);
else
writeb(bin2bcd(value) | AR_ENB, rtc->regbase + reg_off);
}
static int sh_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
{
struct sh_rtc *rtc = dev_get_drvdata(dev);
unsigned int rcr1;
struct rtc_time *tm = &wkalrm->time;
int mon;
spin_lock_irq(&rtc->lock);
/* disable alarm interrupt and clear the alarm flag */
rcr1 = readb(rtc->regbase + RCR1);
rcr1 &= ~(RCR1_AF | RCR1_AIE);
writeb(rcr1, rtc->regbase + RCR1);
/* set alarm time */
sh_rtc_write_alarm_value(rtc, tm->tm_sec, RSECAR);
sh_rtc_write_alarm_value(rtc, tm->tm_min, RMINAR);
sh_rtc_write_alarm_value(rtc, tm->tm_hour, RHRAR);
sh_rtc_write_alarm_value(rtc, tm->tm_wday, RWKAR);
sh_rtc_write_alarm_value(rtc, tm->tm_mday, RDAYAR);
mon = tm->tm_mon;
if (mon >= 0)
mon += 1;
sh_rtc_write_alarm_value(rtc, mon, RMONAR);
if (wkalrm->enabled) {
rcr1 |= RCR1_AIE;
writeb(rcr1, rtc->regbase + RCR1);
}
spin_unlock_irq(&rtc->lock);
return 0;
}
static const struct rtc_class_ops sh_rtc_ops = {
.read_time = sh_rtc_read_time,
.set_time = sh_rtc_set_time,
.read_alarm = sh_rtc_read_alarm,
.set_alarm = sh_rtc_set_alarm,
.proc = sh_rtc_proc,
.alarm_irq_enable = sh_rtc_alarm_irq_enable,
};
static int __init sh_rtc_probe(struct platform_device *pdev)
{
struct sh_rtc *rtc;
struct resource *res;
struct rtc_time r;
char clk_name[6];
int clk_id, ret;
rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
if (unlikely(!rtc))
return -ENOMEM;
spin_lock_init(&rtc->lock);
/* get periodic/carry/alarm irqs */
ret = platform_get_irq(pdev, 0);
if (unlikely(ret <= 0)) {
dev_err(&pdev->dev, "No IRQ resource\n");
return -ENOENT;
}
rtc->periodic_irq = ret;
rtc->carry_irq = platform_get_irq(pdev, 1);
rtc->alarm_irq = platform_get_irq(pdev, 2);
res = platform_get_resource(pdev, IORESOURCE_IO, 0);
if (!res)
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (unlikely(res == NULL)) {
dev_err(&pdev->dev, "No IO resource\n");
return -ENOENT;
}
rtc->regsize = resource_size(res);
rtc->res = devm_request_mem_region(&pdev->dev, res->start,
rtc->regsize, pdev->name);
if (unlikely(!rtc->res))
return -EBUSY;
rtc->regbase = devm_ioremap_nocache(&pdev->dev, rtc->res->start,
rtc->regsize);
if (unlikely(!rtc->regbase))
return -EINVAL;
if (!pdev->dev.of_node) {
clk_id = pdev->id;
/* With a single device, the clock id is still "rtc0" */
if (clk_id < 0)
clk_id = 0;
snprintf(clk_name, sizeof(clk_name), "rtc%d", clk_id);
} else
snprintf(clk_name, sizeof(clk_name), "fck");
rtc->clk = devm_clk_get(&pdev->dev, clk_name);
if (IS_ERR(rtc->clk)) {
/*
* No error handling for rtc->clk intentionally, not all
* platforms will have a unique clock for the RTC, and
* the clk API can handle the struct clk pointer being
* NULL.
*/
rtc->clk = NULL;
}
clk_enable(rtc->clk);
rtc->capabilities = RTC_DEF_CAPABILITIES;
#ifdef CONFIG_SUPERH
if (dev_get_platdata(&pdev->dev)) {
struct sh_rtc_platform_info *pinfo =
dev_get_platdata(&pdev->dev);
/*
* Some CPUs have special capabilities in addition to the
* default set. Add those in here.
*/
rtc->capabilities |= pinfo->capabilities;
}
#endif
if (rtc->carry_irq <= 0) {
/* register shared periodic/carry/alarm irq */
ret = devm_request_irq(&pdev->dev, rtc->periodic_irq,
sh_rtc_shared, 0, "sh-rtc", rtc);
if (unlikely(ret)) {
dev_err(&pdev->dev,
"request IRQ failed with %d, IRQ %d\n", ret,
rtc->periodic_irq);
goto err_unmap;
}
} else {
/* register periodic/carry/alarm irqs */
ret = devm_request_irq(&pdev->dev, rtc->periodic_irq,
sh_rtc_periodic, 0, "sh-rtc period", rtc);
if (unlikely(ret)) {
dev_err(&pdev->dev,
"request period IRQ failed with %d, IRQ %d\n",
ret, rtc->periodic_irq);
goto err_unmap;
}
ret = devm_request_irq(&pdev->dev, rtc->carry_irq,
sh_rtc_interrupt, 0, "sh-rtc carry", rtc);
if (unlikely(ret)) {
dev_err(&pdev->dev,
"request carry IRQ failed with %d, IRQ %d\n",
ret, rtc->carry_irq);
goto err_unmap;
}
ret = devm_request_irq(&pdev->dev, rtc->alarm_irq,
sh_rtc_alarm, 0, "sh-rtc alarm", rtc);
if (unlikely(ret)) {
dev_err(&pdev->dev,
"request alarm IRQ failed with %d, IRQ %d\n",
ret, rtc->alarm_irq);
goto err_unmap;
}
}
platform_set_drvdata(pdev, rtc);
/* everything disabled by default */
sh_rtc_setaie(&pdev->dev, 0);
sh_rtc_setcie(&pdev->dev, 0);
rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, "sh",
&sh_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc->rtc_dev)) {
ret = PTR_ERR(rtc->rtc_dev);
goto err_unmap;
}
rtc->rtc_dev->max_user_freq = 256;
/* reset rtc to epoch 0 if time is invalid */
if (rtc_read_time(rtc->rtc_dev, &r) < 0) {
rtc_time_to_tm(0, &r);
rtc_set_time(rtc->rtc_dev, &r);
}
device_init_wakeup(&pdev->dev, 1);
return 0;
err_unmap:
clk_disable(rtc->clk);
return ret;
}
static int __exit sh_rtc_remove(struct platform_device *pdev)
{
struct sh_rtc *rtc = platform_get_drvdata(pdev);
sh_rtc_setaie(&pdev->dev, 0);
sh_rtc_setcie(&pdev->dev, 0);
clk_disable(rtc->clk);
return 0;
}
static void sh_rtc_set_irq_wake(struct device *dev, int enabled)
{
struct sh_rtc *rtc = dev_get_drvdata(dev);
irq_set_irq_wake(rtc->periodic_irq, enabled);
if (rtc->carry_irq > 0) {
irq_set_irq_wake(rtc->carry_irq, enabled);
irq_set_irq_wake(rtc->alarm_irq, enabled);
}
}
static int __maybe_unused sh_rtc_suspend(struct device *dev)
{
if (device_may_wakeup(dev))
sh_rtc_set_irq_wake(dev, 1);
return 0;
}
static int __maybe_unused sh_rtc_resume(struct device *dev)
{
if (device_may_wakeup(dev))
sh_rtc_set_irq_wake(dev, 0);
return 0;
}
static SIMPLE_DEV_PM_OPS(sh_rtc_pm_ops, sh_rtc_suspend, sh_rtc_resume);
static const struct of_device_id sh_rtc_of_match[] = {
{ .compatible = "renesas,sh-rtc", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, sh_rtc_of_match);
static struct platform_driver sh_rtc_platform_driver = {
.driver = {
.name = DRV_NAME,
.pm = &sh_rtc_pm_ops,
.of_match_table = sh_rtc_of_match,
},
.remove = __exit_p(sh_rtc_remove),
};
module_platform_driver_probe(sh_rtc_platform_driver, sh_rtc_probe);
MODULE_DESCRIPTION("SuperH on-chip RTC driver");
MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, "
"Jamie Lenehan <lenehan@twibble.org>, "
"Angelo Castello <angelo.castello@st.com>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" DRV_NAME);