| Message ID | 20210823163142.586529-2-git@xen0n.name (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | rtc: ls2x: Add support for the Loongson-2K/LS7A RTC | expand |
Hello, 2021年8月24日(火) 1:39 WANG Xuerui <git@xen0n.name>: > > This RTC module is integrated into the Loongson-2K SoC and the LS7A > bridge chip. This version is almost entirely rewritten to make use of > current kernel API. > > Signed-off-by: Huacai Chen <chenhuacai@kernel.org> > Signed-off-by: WANG Xuerui <git@xen0n.name> > Tested-by: Jiaxun Yang <jiaxun.yang@flygoat.com> # loongson2k > Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> > Cc: devicetree@vger.kernel.org > Cc: linux-mips@vger.kernel.org > --- > drivers/rtc/Kconfig | 11 +++ > drivers/rtc/Makefile | 1 + > drivers/rtc/rtc-ls2x.c | 180 +++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 192 insertions(+) > create mode 100644 drivers/rtc/rtc-ls2x.c Reviewed-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org> Best regards, Nobuhiro > > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig > index daff06707455..819f366b4d91 100644 > --- a/drivers/rtc/Kconfig > +++ b/drivers/rtc/Kconfig > @@ -1313,6 +1313,17 @@ config RTC_DRV_NTXEC > embedded controller found in certain e-book readers designed by the > original design manufacturer Netronix. > > +config RTC_DRV_LS2X > + tristate "Loongson LS2X RTC" > + depends on OF && MACH_LOONGSON64 || COMPILE_TEST > + select REGMAP_MMIO > + help > + If you say yes here you get support for the RTC on the Loongson-2K > + SoC and LS7A bridge, which first appeared on the Loongson-2H. > + > + This driver can also be built as a module. If so, the module > + will be called rtc-ls2x. > + > comment "on-CPU RTC drivers" > > config RTC_DRV_ASM9260 > diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile > index 5ceeafe4d5b2..98e68484f519 100644 > --- a/drivers/rtc/Makefile > +++ b/drivers/rtc/Makefile > @@ -83,6 +83,7 @@ obj-$(CONFIG_RTC_DRV_LOONGSON1) += rtc-ls1x.o > obj-$(CONFIG_RTC_DRV_LP8788) += rtc-lp8788.o > obj-$(CONFIG_RTC_DRV_LPC24XX) += rtc-lpc24xx.o > obj-$(CONFIG_RTC_DRV_LPC32XX) += rtc-lpc32xx.o > +obj-$(CONFIG_RTC_DRV_LS2X) += rtc-ls2x.o > obj-$(CONFIG_RTC_DRV_M41T80) += rtc-m41t80.o > obj-$(CONFIG_RTC_DRV_M41T93) += rtc-m41t93.o > obj-$(CONFIG_RTC_DRV_M41T94) += rtc-m41t94.o > diff --git a/drivers/rtc/rtc-ls2x.c b/drivers/rtc/rtc-ls2x.c > new file mode 100644 > index 000000000000..58901323b219 > --- /dev/null > +++ b/drivers/rtc/rtc-ls2x.c > @@ -0,0 +1,180 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Loongson-2K/7A RTC driver > + * > + * Based on the original out-of-tree Loongson-2H RTC driver for Linux 2.6.32, > + * by Shaozong Liu <liushaozong@loongson.cn>. > + * > + * Maintained out-of-tree by Huacai Chen <chenhuacai@kernel.org>. > + * > + * Rewritten for mainline by WANG Xuerui <git@xen0n.name>. > + */ > + > +#include <linux/bitfield.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/platform_device.h> > +#include <linux/regmap.h> > +#include <linux/rtc.h> > + > +#define TOY_TRIM_REG 0x20 > +#define TOY_WRITE0_REG 0x24 > +#define TOY_WRITE1_REG 0x28 > +#define TOY_READ0_REG 0x2c > +#define TOY_READ1_REG 0x30 > +#define TOY_MATCH0_REG 0x34 > +#define TOY_MATCH1_REG 0x38 > +#define TOY_MATCH2_REG 0x3c > +#define RTC_CTRL_REG 0x40 > +#define RTC_TRIM_REG 0x60 > +#define RTC_WRITE0_REG 0x64 > +#define RTC_READ0_REG 0x68 > +#define RTC_MATCH0_REG 0x6c > +#define RTC_MATCH1_REG 0x70 > +#define RTC_MATCH2_REG 0x74 > + > +#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) > + > +struct ls2x_rtc_priv { > + struct regmap *regmap; > +}; > + > +static const struct regmap_config ls2x_rtc_regmap_config = { > + .reg_bits = 32, > + .val_bits = 32, > + .reg_stride = 4, > +}; > + > +struct ls2x_rtc_regs { > + u32 reg0; > + u32 reg1; > +}; > + > +static inline void ls2x_rtc_regs_to_time(struct ls2x_rtc_regs *regs, > + struct rtc_time *tm) > +{ > + tm->tm_year = regs->reg1; > + tm->tm_sec = FIELD_GET(TOY_SEC, regs->reg0); > + tm->tm_min = FIELD_GET(TOY_MIN, regs->reg0); > + tm->tm_hour = FIELD_GET(TOY_HOUR, regs->reg0); > + tm->tm_mday = FIELD_GET(TOY_DAY, regs->reg0); > + tm->tm_mon = FIELD_GET(TOY_MON, regs->reg0) - 1; > +} > + > +static inline void ls2x_rtc_time_to_regs(struct rtc_time *tm, > + struct ls2x_rtc_regs *regs) > +{ > + regs->reg0 = FIELD_PREP(TOY_SEC, tm->tm_sec); > + regs->reg0 |= FIELD_PREP(TOY_MIN, tm->tm_min); > + regs->reg0 |= FIELD_PREP(TOY_HOUR, tm->tm_hour); > + regs->reg0 |= FIELD_PREP(TOY_DAY, tm->tm_mday); > + regs->reg0 |= FIELD_PREP(TOY_MON, tm->tm_mon + 1); > + regs->reg1 = tm->tm_year; > +} > + > +static int ls2x_rtc_read_time(struct device *dev, struct rtc_time *tm) > +{ > + struct ls2x_rtc_priv *priv = dev_get_drvdata(dev); > + struct ls2x_rtc_regs regs; > + int ret; > + > + ret = regmap_read(priv->regmap, TOY_READ1_REG, ®s.reg1); > + if (unlikely(ret)) > + return ret; > + > + ret = regmap_read(priv->regmap, TOY_READ0_REG, ®s.reg0); > + if (unlikely(ret)) > + return ret; > + > + ls2x_rtc_regs_to_time(®s, tm); > + > + return 0; > +} > + > +static int ls2x_rtc_set_time(struct device *dev, struct rtc_time *tm) > +{ > + struct ls2x_rtc_priv *priv = dev_get_drvdata(dev); > + struct ls2x_rtc_regs regs; > + int ret; > + > + ls2x_rtc_time_to_regs(tm, ®s); > + > + ret = regmap_write(priv->regmap, TOY_WRITE0_REG, regs.reg0); > + if (unlikely(ret)) > + return ret; > + > + return regmap_write(priv->regmap, TOY_WRITE1_REG, regs.reg1); > +} > + > +static struct rtc_class_ops ls2x_rtc_ops = { > + .read_time = ls2x_rtc_read_time, > + .set_time = ls2x_rtc_set_time, > +}; > + > +static int ls2x_rtc_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct rtc_device *rtc; > + struct ls2x_rtc_priv *priv; > + void __iomem *regs; > + > + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); > + if (unlikely(!priv)) > + return -ENOMEM; > + > + platform_set_drvdata(pdev, priv); > + > + regs = devm_platform_ioremap_resource(pdev, 0); > + if (IS_ERR(regs)) > + return PTR_ERR(regs); > + > + priv->regmap = devm_regmap_init_mmio(dev, regs, > + &ls2x_rtc_regmap_config); > + if (IS_ERR(priv->regmap)) > + return PTR_ERR(priv->regmap); > + > + rtc = devm_rtc_allocate_device(dev); > + if (IS_ERR(rtc)) > + return PTR_ERR(rtc); > + > + rtc->ops = &ls2x_rtc_ops; > + > + /* Due to hardware erratum, all years multiple of 4 are considered > + * leap year, so only years 2000 through 2099 are usable. > + * > + * Previous out-of-tree versions of this driver wrote tm_year directly > + * into the year register, so epoch 2000 must be used to preserve > + * semantics on shipped systems. > + */ > + rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; > + rtc->range_max = RTC_TIMESTAMP_END_2099; > + > + return devm_rtc_register_device(rtc); > +} > + > +static const struct of_device_id ls2x_rtc_of_match[] = { > + { .compatible = "loongson,ls2x-rtc" }, > + { /* sentinel */ }, > +}; > +MODULE_DEVICE_TABLE(of, ls2x_rtc_of_match); > + > +static struct platform_driver ls2x_rtc_driver = { > + .probe = ls2x_rtc_probe, > + .driver = { > + .name = "ls2x-rtc", > + .of_match_table = ls2x_rtc_of_match, > + }, > +}; > + > +module_platform_driver(ls2x_rtc_driver); > + > +MODULE_DESCRIPTION("LS2X RTC driver"); > +MODULE_AUTHOR("WANG Xuerui"); > +MODULE_AUTHOR("Huacai Chen"); > +MODULE_LICENSE("GPL"); > +MODULE_ALIAS("platform:ls2x-rtc"); > -- > 2.33.0 >
Hello, On 24/08/2021 00:31:37+0800, WANG Xuerui wrote: > This RTC module is integrated into the Loongson-2K SoC and the LS7A > bridge chip. This version is almost entirely rewritten to make use of > current kernel API. > > Signed-off-by: Huacai Chen <chenhuacai@kernel.org> > Signed-off-by: WANG Xuerui <git@xen0n.name> > Tested-by: Jiaxun Yang <jiaxun.yang@flygoat.com> # loongson2k > Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> > Cc: devicetree@vger.kernel.org > Cc: linux-mips@vger.kernel.org > --- > drivers/rtc/Kconfig | 11 +++ > drivers/rtc/Makefile | 1 + > drivers/rtc/rtc-ls2x.c | 180 +++++++++++++++++++++++++++++++++++++++++ Note that I'm still concerned this duplicates rtc-ls1x.c > 3 files changed, 192 insertions(+) > create mode 100644 drivers/rtc/rtc-ls2x.c > > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig > index daff06707455..819f366b4d91 100644 > --- a/drivers/rtc/Kconfig > +++ b/drivers/rtc/Kconfig > @@ -1313,6 +1313,17 @@ config RTC_DRV_NTXEC > embedded controller found in certain e-book readers designed by the > original design manufacturer Netronix. > > +config RTC_DRV_LS2X > + tristate "Loongson LS2X RTC" > + depends on OF && MACH_LOONGSON64 || COMPILE_TEST > + select REGMAP_MMIO > + help > + If you say yes here you get support for the RTC on the Loongson-2K > + SoC and LS7A bridge, which first appeared on the Loongson-2H. > + > + This driver can also be built as a module. If so, the module > + will be called rtc-ls2x. > + > comment "on-CPU RTC drivers" > > config RTC_DRV_ASM9260 > diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile > index 5ceeafe4d5b2..98e68484f519 100644 > --- a/drivers/rtc/Makefile > +++ b/drivers/rtc/Makefile > @@ -83,6 +83,7 @@ obj-$(CONFIG_RTC_DRV_LOONGSON1) += rtc-ls1x.o > obj-$(CONFIG_RTC_DRV_LP8788) += rtc-lp8788.o > obj-$(CONFIG_RTC_DRV_LPC24XX) += rtc-lpc24xx.o > obj-$(CONFIG_RTC_DRV_LPC32XX) += rtc-lpc32xx.o > +obj-$(CONFIG_RTC_DRV_LS2X) += rtc-ls2x.o > obj-$(CONFIG_RTC_DRV_M41T80) += rtc-m41t80.o > obj-$(CONFIG_RTC_DRV_M41T93) += rtc-m41t93.o > obj-$(CONFIG_RTC_DRV_M41T94) += rtc-m41t94.o > diff --git a/drivers/rtc/rtc-ls2x.c b/drivers/rtc/rtc-ls2x.c > new file mode 100644 > index 000000000000..58901323b219 > --- /dev/null > +++ b/drivers/rtc/rtc-ls2x.c > @@ -0,0 +1,180 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Loongson-2K/7A RTC driver > + * > + * Based on the original out-of-tree Loongson-2H RTC driver for Linux 2.6.32, > + * by Shaozong Liu <liushaozong@loongson.cn>. > + * > + * Maintained out-of-tree by Huacai Chen <chenhuacai@kernel.org>. > + * > + * Rewritten for mainline by WANG Xuerui <git@xen0n.name>. > + */ > + > +#include <linux/bitfield.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/platform_device.h> > +#include <linux/regmap.h> > +#include <linux/rtc.h> > + > +#define TOY_TRIM_REG 0x20 > +#define TOY_WRITE0_REG 0x24 > +#define TOY_WRITE1_REG 0x28 > +#define TOY_READ0_REG 0x2c > +#define TOY_READ1_REG 0x30 > +#define TOY_MATCH0_REG 0x34 > +#define TOY_MATCH1_REG 0x38 > +#define TOY_MATCH2_REG 0x3c > +#define RTC_CTRL_REG 0x40 > +#define RTC_TRIM_REG 0x60 > +#define RTC_WRITE0_REG 0x64 > +#define RTC_READ0_REG 0x68 > +#define RTC_MATCH0_REG 0x6c > +#define RTC_MATCH1_REG 0x70 > +#define RTC_MATCH2_REG 0x74 > + > +#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) > + > +struct ls2x_rtc_priv { > + struct regmap *regmap; > +}; > + > +static const struct regmap_config ls2x_rtc_regmap_config = { > + .reg_bits = 32, > + .val_bits = 32, > + .reg_stride = 4, > +}; > + > +struct ls2x_rtc_regs { > + u32 reg0; > + u32 reg1; > +}; > + > +static inline void ls2x_rtc_regs_to_time(struct ls2x_rtc_regs *regs, > + struct rtc_time *tm) > +{ > + tm->tm_year = regs->reg1; > + tm->tm_sec = FIELD_GET(TOY_SEC, regs->reg0); > + tm->tm_min = FIELD_GET(TOY_MIN, regs->reg0); > + tm->tm_hour = FIELD_GET(TOY_HOUR, regs->reg0); > + tm->tm_mday = FIELD_GET(TOY_DAY, regs->reg0); > + tm->tm_mon = FIELD_GET(TOY_MON, regs->reg0) - 1; > +} > + > +static inline void ls2x_rtc_time_to_regs(struct rtc_time *tm, > + struct ls2x_rtc_regs *regs) > +{ > + regs->reg0 = FIELD_PREP(TOY_SEC, tm->tm_sec); > + regs->reg0 |= FIELD_PREP(TOY_MIN, tm->tm_min); > + regs->reg0 |= FIELD_PREP(TOY_HOUR, tm->tm_hour); > + regs->reg0 |= FIELD_PREP(TOY_DAY, tm->tm_mday); > + regs->reg0 |= FIELD_PREP(TOY_MON, tm->tm_mon + 1); > + regs->reg1 = tm->tm_year; > +} > + > +static int ls2x_rtc_read_time(struct device *dev, struct rtc_time *tm) > +{ > + struct ls2x_rtc_priv *priv = dev_get_drvdata(dev); > + struct ls2x_rtc_regs regs; > + int ret; > + > + ret = regmap_read(priv->regmap, TOY_READ1_REG, ®s.reg1); > + if (unlikely(ret)) > + return ret; > + > + ret = regmap_read(priv->regmap, TOY_READ0_REG, ®s.reg0); > + if (unlikely(ret)) > + return ret; > + I'm actually wondering why you read first TOY_READ1_REG then TOY_READ0_REG. ls1x does the opposite and the ls1c datasheet I found doesn't mention any latching happening. So unless latching is done on TOY_READ1_REG, you could use regmap_bulk_read and simply avoid struct ls2x_rtc_regs. If there is no latching, you may need to read TOY_READ0_REG at least twice. Because TOY_READ1_REG only contains the year, it is an issue only on 31 of December and it will not be easy to reproduce.
On 24/08/2021 00:31:37+0800, WANG Xuerui wrote: > + > +static struct rtc_class_ops ls2x_rtc_ops = { I forgot to add that this should be const > + .read_time = ls2x_rtc_read_time, > + .set_time = ls2x_rtc_set_time, > +}; > +
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index daff06707455..819f366b4d91 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -1313,6 +1313,17 @@ config RTC_DRV_NTXEC embedded controller found in certain e-book readers designed by the original design manufacturer Netronix. +config RTC_DRV_LS2X + tristate "Loongson LS2X RTC" + depends on OF && MACH_LOONGSON64 || COMPILE_TEST + select REGMAP_MMIO + help + If you say yes here you get support for the RTC on the Loongson-2K + SoC and LS7A bridge, which first appeared on the Loongson-2H. + + This driver can also be built as a module. If so, the module + will be called rtc-ls2x. + comment "on-CPU RTC drivers" config RTC_DRV_ASM9260 diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index 5ceeafe4d5b2..98e68484f519 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -83,6 +83,7 @@ obj-$(CONFIG_RTC_DRV_LOONGSON1) += rtc-ls1x.o obj-$(CONFIG_RTC_DRV_LP8788) += rtc-lp8788.o obj-$(CONFIG_RTC_DRV_LPC24XX) += rtc-lpc24xx.o obj-$(CONFIG_RTC_DRV_LPC32XX) += rtc-lpc32xx.o +obj-$(CONFIG_RTC_DRV_LS2X) += rtc-ls2x.o obj-$(CONFIG_RTC_DRV_M41T80) += rtc-m41t80.o obj-$(CONFIG_RTC_DRV_M41T93) += rtc-m41t93.o obj-$(CONFIG_RTC_DRV_M41T94) += rtc-m41t94.o diff --git a/drivers/rtc/rtc-ls2x.c b/drivers/rtc/rtc-ls2x.c new file mode 100644 index 000000000000..58901323b219 --- /dev/null +++ b/drivers/rtc/rtc-ls2x.c @@ -0,0 +1,180 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Loongson-2K/7A RTC driver + * + * Based on the original out-of-tree Loongson-2H RTC driver for Linux 2.6.32, + * by Shaozong Liu <liushaozong@loongson.cn>. + * + * Maintained out-of-tree by Huacai Chen <chenhuacai@kernel.org>. + * + * Rewritten for mainline by WANG Xuerui <git@xen0n.name>. + */ + +#include <linux/bitfield.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/rtc.h> + +#define TOY_TRIM_REG 0x20 +#define TOY_WRITE0_REG 0x24 +#define TOY_WRITE1_REG 0x28 +#define TOY_READ0_REG 0x2c +#define TOY_READ1_REG 0x30 +#define TOY_MATCH0_REG 0x34 +#define TOY_MATCH1_REG 0x38 +#define TOY_MATCH2_REG 0x3c +#define RTC_CTRL_REG 0x40 +#define RTC_TRIM_REG 0x60 +#define RTC_WRITE0_REG 0x64 +#define RTC_READ0_REG 0x68 +#define RTC_MATCH0_REG 0x6c +#define RTC_MATCH1_REG 0x70 +#define RTC_MATCH2_REG 0x74 + +#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) + +struct ls2x_rtc_priv { + struct regmap *regmap; +}; + +static const struct regmap_config ls2x_rtc_regmap_config = { + .reg_bits = 32, + .val_bits = 32, + .reg_stride = 4, +}; + +struct ls2x_rtc_regs { + u32 reg0; + u32 reg1; +}; + +static inline void ls2x_rtc_regs_to_time(struct ls2x_rtc_regs *regs, + struct rtc_time *tm) +{ + tm->tm_year = regs->reg1; + tm->tm_sec = FIELD_GET(TOY_SEC, regs->reg0); + tm->tm_min = FIELD_GET(TOY_MIN, regs->reg0); + tm->tm_hour = FIELD_GET(TOY_HOUR, regs->reg0); + tm->tm_mday = FIELD_GET(TOY_DAY, regs->reg0); + tm->tm_mon = FIELD_GET(TOY_MON, regs->reg0) - 1; +} + +static inline void ls2x_rtc_time_to_regs(struct rtc_time *tm, + struct ls2x_rtc_regs *regs) +{ + regs->reg0 = FIELD_PREP(TOY_SEC, tm->tm_sec); + regs->reg0 |= FIELD_PREP(TOY_MIN, tm->tm_min); + regs->reg0 |= FIELD_PREP(TOY_HOUR, tm->tm_hour); + regs->reg0 |= FIELD_PREP(TOY_DAY, tm->tm_mday); + regs->reg0 |= FIELD_PREP(TOY_MON, tm->tm_mon + 1); + regs->reg1 = tm->tm_year; +} + +static int ls2x_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct ls2x_rtc_priv *priv = dev_get_drvdata(dev); + struct ls2x_rtc_regs regs; + int ret; + + ret = regmap_read(priv->regmap, TOY_READ1_REG, ®s.reg1); + if (unlikely(ret)) + return ret; + + ret = regmap_read(priv->regmap, TOY_READ0_REG, ®s.reg0); + if (unlikely(ret)) + return ret; + + ls2x_rtc_regs_to_time(®s, tm); + + return 0; +} + +static int ls2x_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct ls2x_rtc_priv *priv = dev_get_drvdata(dev); + struct ls2x_rtc_regs regs; + int ret; + + ls2x_rtc_time_to_regs(tm, ®s); + + ret = regmap_write(priv->regmap, TOY_WRITE0_REG, regs.reg0); + if (unlikely(ret)) + return ret; + + return regmap_write(priv->regmap, TOY_WRITE1_REG, regs.reg1); +} + +static struct rtc_class_ops ls2x_rtc_ops = { + .read_time = ls2x_rtc_read_time, + .set_time = ls2x_rtc_set_time, +}; + +static int ls2x_rtc_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct rtc_device *rtc; + struct ls2x_rtc_priv *priv; + void __iomem *regs; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (unlikely(!priv)) + return -ENOMEM; + + platform_set_drvdata(pdev, priv); + + regs = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(regs)) + return PTR_ERR(regs); + + priv->regmap = devm_regmap_init_mmio(dev, regs, + &ls2x_rtc_regmap_config); + if (IS_ERR(priv->regmap)) + return PTR_ERR(priv->regmap); + + rtc = devm_rtc_allocate_device(dev); + if (IS_ERR(rtc)) + return PTR_ERR(rtc); + + rtc->ops = &ls2x_rtc_ops; + + /* Due to hardware erratum, all years multiple of 4 are considered + * leap year, so only years 2000 through 2099 are usable. + * + * Previous out-of-tree versions of this driver wrote tm_year directly + * into the year register, so epoch 2000 must be used to preserve + * semantics on shipped systems. + */ + rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; + rtc->range_max = RTC_TIMESTAMP_END_2099; + + return devm_rtc_register_device(rtc); +} + +static const struct of_device_id ls2x_rtc_of_match[] = { + { .compatible = "loongson,ls2x-rtc" }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, ls2x_rtc_of_match); + +static struct platform_driver ls2x_rtc_driver = { + .probe = ls2x_rtc_probe, + .driver = { + .name = "ls2x-rtc", + .of_match_table = ls2x_rtc_of_match, + }, +}; + +module_platform_driver(ls2x_rtc_driver); + +MODULE_DESCRIPTION("LS2X RTC driver"); +MODULE_AUTHOR("WANG Xuerui"); +MODULE_AUTHOR("Huacai Chen"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:ls2x-rtc");