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rtc: Add rtc driver for the Loongson family chips

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The Loongson family chips use an on-chip counter 0 (Time Of Year
counter) as the RTC. We will refer to them as rtc-loongson.

Cc: Keguang Zhang <keguang.zhang@gmail.com>
Cc: Yang Ling <gnaygnil@gmail.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@kernel.org>
Signed-off-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Keguang Zhang <keguang.zhang@gmail.com>
Tested-by: Keguang Zhang <keguang.zhang@gmail.com>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Tested-by: Jiaxun Yang <jiaxun.yang@flygoat.com> # LS7A
Link: https://lore.kernel.org/r/0c5171156390f614d72f36ceb04a20f432ca639e.1685693501.git.zhoubinbin@loongson.cn
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
This commit is contained in:
Binbin Zhou 2023-06-02 17:50:48 +08:00 committed by Alexandre Belloni
parent 9fb2309065
commit 1b733a9ebc
3 changed files with 411 additions and 0 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

13
drivers/rtc/Kconfig
View file

@ -1687,6 +1687,19 @@ config RTC_DRV_JZ4740
This driver can also be built as a module. If so, the module
will be called rtc-jz4740.
config RTC_DRV_LOONGSON
tristate "Loongson On-chip RTC"
depends on MACH_LOONGSON32 || MACH_LOONGSON64 || COMPILE_TEST
select REGMAP_MMIO
help
This is a driver for the Loongson on-chip Counter0 (Time-Of-Year
counter) to be used as a RTC.
It can be found on Loongson-1 series cpu, Loongson-2K series cpu
and Loongson LS7A bridge chips.
This driver can also be built as a module. If so, the module
will be called rtc-loongson.
config RTC_DRV_LPC24XX
tristate "NXP RTC for LPC178x/18xx/408x/43xx"
depends on ARCH_LPC18XX || COMPILE_TEST

1
drivers/rtc/Makefile
View file

@ -78,6 +78,7 @@ obj-$(CONFIG_RTC_DRV_ISL12022) += rtc-isl12022.o
obj-$(CONFIG_RTC_DRV_ISL12026) += rtc-isl12026.o
obj-$(CONFIG_RTC_DRV_ISL1208) += rtc-isl1208.o
obj-$(CONFIG_RTC_DRV_JZ4740) += rtc-jz4740.o
obj-$(CONFIG_RTC_DRV_LOONGSON) += rtc-loongson.o
obj-$(CONFIG_RTC_DRV_LP8788) += rtc-lp8788.o
obj-$(CONFIG_RTC_DRV_LPC24XX) += rtc-lpc24xx.o
obj-$(CONFIG_RTC_DRV_LPC32XX) += rtc-lpc32xx.o

397
drivers/rtc/rtc-loongson.c Normal file
View file

@ -0,0 +1,397 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Loongson RTC driver
*
* Maintained out-of-tree by Huacai Chen <chenhuacai@kernel.org>.
* Rewritten for mainline by WANG Xuerui <git@xen0n.name>.
* Binbin Zhou <zhoubinbin@loongson.cn>
*/
#include <linux/bitfield.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/rtc.h>
#include <linux/acpi.h>
/* Time Of Year(TOY) counters registers */
#define TOY_TRIM_REG 0x20 /* Must be initialized to 0 */
#define TOY_WRITE0_REG 0x24 /* TOY low 32-bits value (write-only) */
#define TOY_WRITE1_REG 0x28 /* TOY high 32-bits value (write-only) */
#define TOY_READ0_REG 0x2c /* TOY low 32-bits value (read-only) */
#define TOY_READ1_REG 0x30 /* TOY high 32-bits value (read-only) */
#define TOY_MATCH0_REG 0x34 /* TOY timing interrupt 0 */
#define TOY_MATCH1_REG 0x38 /* TOY timing interrupt 1 */
#define TOY_MATCH2_REG 0x3c /* TOY timing interrupt 2 */
/* RTC counters registers */
#define RTC_CTRL_REG 0x40 /* TOY and RTC control register */
#define RTC_TRIM_REG 0x60 /* Must be initialized to 0 */
#define RTC_WRITE0_REG 0x64 /* RTC counters value (write-only) */
#define RTC_READ0_REG 0x68 /* RTC counters value (read-only) */
#define RTC_MATCH0_REG 0x6c /* RTC timing interrupt 0 */
#define RTC_MATCH1_REG 0x70 /* RTC timing interrupt 1 */
#define RTC_MATCH2_REG 0x74 /* RTC timing interrupt 2 */
/* bitmask of TOY_WRITE0_REG */
#define TOY_MON GENMASK(31, 26)
#define TOY_DAY GENMASK(25, 21)
#define TOY_HOUR GENMASK(20, 16)
#define TOY_MIN GENMASK(15, 10)
#define TOY_SEC GENMASK(9, 4)
#define TOY_MSEC GENMASK(3, 0)
/* bitmask of TOY_MATCH0/1/2_REG */
#define TOY_MATCH_YEAR GENMASK(31, 26)
#define TOY_MATCH_MON GENMASK(25, 22)
#define TOY_MATCH_DAY GENMASK(21, 17)
#define TOY_MATCH_HOUR GENMASK(16, 12)
#define TOY_MATCH_MIN GENMASK(11, 6)
#define TOY_MATCH_SEC GENMASK(5, 0)
/* bitmask of RTC_CTRL_REG */
#define RTC_ENABLE BIT(13) /* 1: RTC counters enable */
#define TOY_ENABLE BIT(11) /* 1: TOY counters enable */
#define OSC_ENABLE BIT(8) /* 1: 32.768k crystal enable */
#define TOY_ENABLE_MASK (TOY_ENABLE | OSC_ENABLE)
/* PM domain registers */
#define PM1_STS_REG 0x0c /* Power management 1 status register */
#define RTC_STS BIT(10) /* RTC status */
#define PM1_EN_REG 0x10 /* Power management 1 enable register */
#define RTC_EN BIT(10) /* RTC event enable */
/*
* According to the LS1C manual, RTC_CTRL and alarm-related registers are not defined.
* Accessing the relevant registers will cause the system to hang.
*/
#define LS1C_RTC_CTRL_WORKAROUND BIT(0)
struct loongson_rtc_config {
u32 pm_offset; /* Offset of PM domain, for RTC alarm wakeup */
u32 flags; /* Workaround bits */
};
struct loongson_rtc_priv {
spinlock_t lock; /* protects PM registers access */
u32 fix_year; /* RTC alarm year compensation value */
struct rtc_device *rtcdev;
struct regmap *regmap;
void __iomem *pm_base; /* PM domain base, for RTC alarm wakeup */
const struct loongson_rtc_config *config;
};
static const struct loongson_rtc_config ls1b_rtc_config = {
.pm_offset = 0,
.flags = 0,
};
static const struct loongson_rtc_config ls1c_rtc_config = {
.pm_offset = 0,
.flags = LS1C_RTC_CTRL_WORKAROUND,
};
static const struct loongson_rtc_config generic_rtc_config = {
.pm_offset = 0x100,
.flags = 0,
};
static const struct loongson_rtc_config ls2k1000_rtc_config = {
.pm_offset = 0x800,
.flags = 0,
};
static const struct regmap_config loongson_rtc_regmap_config = {
.reg_bits = 32,
.val_bits = 32,
.reg_stride = 4,
};
/* RTC alarm irq handler */
static irqreturn_t loongson_rtc_isr(int irq, void *id)
{
struct loongson_rtc_priv *priv = (struct loongson_rtc_priv *)id;
rtc_update_irq(priv->rtcdev, 1, RTC_AF | RTC_IRQF);
return IRQ_HANDLED;
}
/* For ACPI fixed event handler */
static u32 loongson_rtc_handler(void *id)
{
struct loongson_rtc_priv *priv = (struct loongson_rtc_priv *)id;
spin_lock(&priv->lock);
/* Disable RTC alarm wakeup and interrupt */
writel(readl(priv->pm_base + PM1_EN_REG) & ~RTC_EN,
priv->pm_base + PM1_EN_REG);
/* Clear RTC interrupt status */
writel(RTC_STS, priv->pm_base + PM1_STS_REG);
spin_unlock(&priv->lock);
/*
* The TOY_MATCH0_REG should be cleared 0 here,
* otherwise the interrupt cannot be cleared.
*/
return regmap_write(priv->regmap, TOY_MATCH0_REG, 0);
}
static int loongson_rtc_set_enabled(struct device *dev)
{
struct loongson_rtc_priv *priv = dev_get_drvdata(dev);
if (priv->config->flags & LS1C_RTC_CTRL_WORKAROUND)
return 0;
/* Enable RTC TOY counters and crystal */
return regmap_update_bits(priv->regmap, RTC_CTRL_REG, TOY_ENABLE_MASK,
TOY_ENABLE_MASK);
}
static bool loongson_rtc_get_enabled(struct device *dev)
{
int ret;
u32 ctrl_data;
struct loongson_rtc_priv *priv = dev_get_drvdata(dev);
if (priv->config->flags & LS1C_RTC_CTRL_WORKAROUND)
return true;
ret = regmap_read(priv->regmap, RTC_CTRL_REG, &ctrl_data);
if (ret < 0)
return false;
return ctrl_data & TOY_ENABLE_MASK;
}
static int loongson_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
int ret;
u32 rtc_data[2];
struct loongson_rtc_priv *priv = dev_get_drvdata(dev);
if (!loongson_rtc_get_enabled(dev))
return -EINVAL;
ret = regmap_bulk_read(priv->regmap, TOY_READ0_REG, rtc_data,
ARRAY_SIZE(rtc_data));
if (ret < 0)
return ret;
tm->tm_sec = FIELD_GET(TOY_SEC, rtc_data[0]);
tm->tm_min = FIELD_GET(TOY_MIN, rtc_data[0]);
tm->tm_hour = FIELD_GET(TOY_HOUR, rtc_data[0]);
tm->tm_mday = FIELD_GET(TOY_DAY, rtc_data[0]);
tm->tm_mon = FIELD_GET(TOY_MON, rtc_data[0]) - 1;
tm->tm_year = rtc_data[1];
/* Prepare for RTC alarm year compensation value. */
priv->fix_year = tm->tm_year / 64 * 64;
return 0;
}
static int loongson_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
int ret;
u32 rtc_data[2];
struct loongson_rtc_priv *priv = dev_get_drvdata(dev);
rtc_data[0] = FIELD_PREP(TOY_SEC, tm->tm_sec)
| FIELD_PREP(TOY_MIN, tm->tm_min)
| FIELD_PREP(TOY_HOUR, tm->tm_hour)
| FIELD_PREP(TOY_DAY, tm->tm_mday)
| FIELD_PREP(TOY_MON, tm->tm_mon + 1);
rtc_data[1] = tm->tm_year;
ret = regmap_bulk_write(priv->regmap, TOY_WRITE0_REG, rtc_data,
ARRAY_SIZE(rtc_data));
if (ret < 0)
return ret;
return loongson_rtc_set_enabled(dev);
}
static int loongson_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
int ret;
u32 alarm_data;
struct loongson_rtc_priv *priv = dev_get_drvdata(dev);
ret = regmap_read(priv->regmap, TOY_MATCH0_REG, &alarm_data);
if (ret < 0)
return ret;
alrm->time.tm_sec = FIELD_GET(TOY_MATCH_SEC, alarm_data);
alrm->time.tm_min = FIELD_GET(TOY_MATCH_MIN, alarm_data);
alrm->time.tm_hour = FIELD_GET(TOY_MATCH_HOUR, alarm_data);
alrm->time.tm_mday = FIELD_GET(TOY_MATCH_DAY, alarm_data);
alrm->time.tm_mon = FIELD_GET(TOY_MATCH_MON, alarm_data) - 1;
/*
* This is a hardware bug: the year field of SYS_TOYMATCH is only 6 bits,
* making it impossible to save year values larger than 64.
*
* SYS_TOYMATCH is used to match the alarm time value and determine if
* an alarm is triggered, so we must keep the lower 6 bits of the year
* value constant during the value conversion.
*
* In summary, we need to manually add 64(or a multiple of 64) to the
* year value to avoid the invalid alarm prompt at startup.
*/
alrm->time.tm_year = FIELD_GET(TOY_MATCH_YEAR, alarm_data) + priv->fix_year;
alrm->enabled = !!(readl(priv->pm_base + PM1_EN_REG) & RTC_EN);
return 0;
}
static int loongson_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
u32 val;
struct loongson_rtc_priv *priv = dev_get_drvdata(dev);
spin_lock(&priv->lock);
val = readl(priv->pm_base + PM1_EN_REG);
/* Enable RTC alarm wakeup */
writel(enabled ? val | RTC_EN : val & ~RTC_EN,
priv->pm_base + PM1_EN_REG);
spin_unlock(&priv->lock);
return 0;
}
static int loongson_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
int ret;
u32 alarm_data;
struct loongson_rtc_priv *priv = dev_get_drvdata(dev);
alarm_data = FIELD_PREP(TOY_MATCH_SEC, alrm->time.tm_sec)
| FIELD_PREP(TOY_MATCH_MIN, alrm->time.tm_min)
| FIELD_PREP(TOY_MATCH_HOUR, alrm->time.tm_hour)
| FIELD_PREP(TOY_MATCH_DAY, alrm->time.tm_mday)
| FIELD_PREP(TOY_MATCH_MON, alrm->time.tm_mon + 1)
| FIELD_PREP(TOY_MATCH_YEAR, alrm->time.tm_year - priv->fix_year);
ret = regmap_write(priv->regmap, TOY_MATCH0_REG, alarm_data);
if (ret < 0)
return ret;
return loongson_rtc_alarm_irq_enable(dev, alrm->enabled);
}
static const struct rtc_class_ops loongson_rtc_ops = {
.read_time = loongson_rtc_read_time,
.set_time = loongson_rtc_set_time,
.read_alarm = loongson_rtc_read_alarm,
.set_alarm = loongson_rtc_set_alarm,
.alarm_irq_enable = loongson_rtc_alarm_irq_enable,
};
static int loongson_rtc_probe(struct platform_device *pdev)
{
int ret, alarm_irq;
void __iomem *regs;
struct loongson_rtc_priv *priv;
struct device *dev = &pdev->dev;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(regs))
return dev_err_probe(dev, PTR_ERR(regs),
"devm_platform_ioremap_resource failed\n");
priv->regmap = devm_regmap_init_mmio(dev, regs,
&loongson_rtc_regmap_config);
if (IS_ERR(priv->regmap))
return dev_err_probe(dev, PTR_ERR(priv->regmap),
"devm_regmap_init_mmio failed\n");
priv->config = device_get_match_data(dev);
spin_lock_init(&priv->lock);
platform_set_drvdata(pdev, priv);
priv->rtcdev = devm_rtc_allocate_device(dev);
if (IS_ERR(priv->rtcdev))
return dev_err_probe(dev, PTR_ERR(priv->rtcdev),
"devm_rtc_allocate_device failed\n");
/* Get RTC alarm irq */
alarm_irq = platform_get_irq(pdev, 0);
if (alarm_irq > 0) {
ret = devm_request_irq(dev, alarm_irq, loongson_rtc_isr,
0, "loongson-alarm", priv);
if (ret < 0)
return dev_err_probe(dev, ret, "Unable to request irq %d\n",
alarm_irq);
priv->pm_base = regs - priv->config->pm_offset;
device_init_wakeup(dev, 1);
if (has_acpi_companion(dev))
acpi_install_fixed_event_handler(ACPI_EVENT_RTC,
loongson_rtc_handler, priv);
} else {
/* Loongson-1C RTC does not support alarm */
clear_bit(RTC_FEATURE_ALARM, priv->rtcdev->features);
}
/* Loongson RTC does not support UIE */
clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, priv->rtcdev->features);
priv->rtcdev->ops = &loongson_rtc_ops;
priv->rtcdev->range_min = RTC_TIMESTAMP_BEGIN_2000;
priv->rtcdev->range_max = RTC_TIMESTAMP_END_2099;
return devm_rtc_register_device(priv->rtcdev);
}
static void loongson_rtc_remove(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct loongson_rtc_priv *priv = dev_get_drvdata(dev);
if (!test_bit(RTC_FEATURE_ALARM, priv->rtcdev->features))
return;
if (has_acpi_companion(dev))
acpi_remove_fixed_event_handler(ACPI_EVENT_RTC,
loongson_rtc_handler);
device_init_wakeup(dev, 0);
loongson_rtc_alarm_irq_enable(dev, 0);
}
static const struct of_device_id loongson_rtc_of_match[] = {
{ .compatible = "loongson,ls1b-rtc", .data = &ls1b_rtc_config },
{ .compatible = "loongson,ls1c-rtc", .data = &ls1c_rtc_config },
{ .compatible = "loongson,ls7a-rtc", .data = &generic_rtc_config },
{ .compatible = "loongson,ls2k1000-rtc", .data = &ls2k1000_rtc_config },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, loongson_rtc_of_match);
static const struct acpi_device_id loongson_rtc_acpi_match[] = {
{ "LOON0001", .driver_data = (kernel_ulong_t)&generic_rtc_config },
{ }
};
MODULE_DEVICE_TABLE(acpi, loongson_rtc_acpi_match);
static struct platform_driver loongson_rtc_driver = {
.probe = loongson_rtc_probe,
.remove_new = loongson_rtc_remove,
.driver = {
.name = "loongson-rtc",
.of_match_table = loongson_rtc_of_match,
.acpi_match_table = loongson_rtc_acpi_match,
},
};
module_platform_driver(loongson_rtc_driver);
MODULE_DESCRIPTION("Loongson RTC driver");
MODULE_AUTHOR("Binbin Zhou <zhoubinbin@loongson.cn>");
MODULE_AUTHOR("WANG Xuerui <git@xen0n.name>");
MODULE_AUTHOR("Huacai Chen <chenhuacai@kernel.org>");
MODULE_LICENSE("GPL");