rtc: loongson: Add Loongson-2K0300 support

The Loongson-2K0300's rtc hardware design is similar to that of the
Loongson-1B, but it does not support the alarm feature.

Introduce `LOONGSON_RTC_ALARM_WORKAROUND`, which indicates a chip that
does not support the alarm feature, and rewrite the related logic in
`loongson_rtc_alarm_setting()`.

Reviewed-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
Link: https://patch.msgid.link/abff68dda2fe6a6601a9e58b31e278d941297fce.1768616276.git.zhoubinbin@loongson.cn
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

diff --git a/drivers/rtc/rtc-loongson.c b/drivers/rtc/rtc-loongson.c
index 2ca7ffd..066f064 100644 (file)
--- a/drivers/rtc/rtc-loongson.c
+++ b/drivers/rtc/rtc-loongson.c
@@ -66,7 +66,8 @@
  * 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)
+#define LOONGSON_RTC_CTRL_WORKAROUND   BIT(0)
+#define LOONGSON_RTC_ALARM_WORKAROUND  BIT(1)
 
 struct loongson_rtc_config {
        u32 pm_offset;  /* Offset of PM domain, for RTC alarm wakeup */
@@ -89,7 +90,7 @@ static const struct loongson_rtc_config ls1b_rtc_config = {
 
 static const struct loongson_rtc_config ls1c_rtc_config = {
        .pm_offset = 0,
-       .flags = LS1C_RTC_CTRL_WORKAROUND,
+       .flags = LOONGSON_RTC_CTRL_WORKAROUND | LOONGSON_RTC_ALARM_WORKAROUND,
 };
 
 static const struct loongson_rtc_config generic_rtc_config = {
@@ -97,6 +98,11 @@ static const struct loongson_rtc_config generic_rtc_config = {
        .flags = 0,
 };
 
+static const struct loongson_rtc_config ls2k0300_rtc_config = {
+       .pm_offset = 0x0,
+       .flags = LOONGSON_RTC_ALARM_WORKAROUND,
+};
+
 static const struct loongson_rtc_config ls2k1000_rtc_config = {
        .pm_offset = 0x800,
        .flags = 0,
@@ -153,7 +159,7 @@ 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)
+       if (priv->config->flags & LOONGSON_RTC_CTRL_WORKAROUND)
                return 0;
 
        /* Enable RTC TOY counters and crystal */
@@ -167,7 +173,7 @@ static bool loongson_rtc_get_enabled(struct device *dev)
        u32 ctrl_data;
        struct loongson_rtc_priv *priv = dev_get_drvdata(dev);
 
-       if (priv->config->flags & LS1C_RTC_CTRL_WORKAROUND)
+       if (priv->config->flags & LOONGSON_RTC_CTRL_WORKAROUND)
                return true;
 
        ret = regmap_read(priv->regmap, RTC_CTRL_REG, &ctrl_data);
@@ -299,9 +305,41 @@ static const struct rtc_class_ops loongson_rtc_ops = {
        .alarm_irq_enable = loongson_rtc_alarm_irq_enable,
 };
 
+static int loongson_rtc_alarm_setting(struct platform_device *pdev, void __iomem *regs)
+{
+       int ret = 0, alarm_irq;
+       struct device *dev = &pdev->dev;
+       struct loongson_rtc_priv *priv = dev_get_drvdata(dev);
+
+       if (priv->config->flags & LOONGSON_RTC_ALARM_WORKAROUND) {
+               /* Loongson-1C/Loongson-2K0300 RTC does not support alarm */
+               clear_bit(RTC_FEATURE_ALARM, priv->rtcdev->features);
+               return 0;
+       }
+
+       /* Get RTC alarm irq */
+       alarm_irq = platform_get_irq(pdev, 0);
+       if (alarm_irq < 0)
+               return alarm_irq;
+
+       ret = devm_request_irq(dev, alarm_irq, loongson_rtc_isr, 0, "loongson-alarm",
+                              priv);
+       if (ret < 0)
+               return ret;
+
+       priv->pm_base = regs - priv->config->pm_offset;
+       device_init_wakeup(dev, true);
+
+       if (has_acpi_companion(dev))
+               acpi_install_fixed_event_handler(ACPI_EVENT_RTC,
+                                                loongson_rtc_handler, priv);
+
+       return ret;
+}
+
 static int loongson_rtc_probe(struct platform_device *pdev)
 {
-       int ret, alarm_irq;
+       int ret;
        void __iomem *regs;
        struct loongson_rtc_priv *priv;
        struct device *dev = &pdev->dev;
@@ -330,25 +368,9 @@ static int loongson_rtc_probe(struct platform_device *pdev)
                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, true);
-
-               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);
-       }
+       ret = loongson_rtc_alarm_setting(pdev, regs);
+       if (ret)
+               return ret;
 
        /* Loongson RTC does not support UIE */
        clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, priv->rtcdev->features);
@@ -379,6 +401,7 @@ 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,ls2k0300-rtc", .data = &ls2k0300_rtc_config },
        { .compatible = "loongson,ls2k1000-rtc", .data = &ls2k1000_rtc_config },
        { /* sentinel */ }
 };