rtc: omap: Support ext_wakeup configuration

Support configuration of ext_wakeup sources. This patch makes it
possible to enable ext_wakeup and set it's polarity, depending on board
configuration. AM335x's dedicated PMIC (tps65217) uses ext_wakeup to
notify about power-button presses. Handling power-button presses enables
to recover from RTC-only power states correctly.

Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

2 files changed, 163 insertions, 8 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 896302a0d4b9..531343a260f8 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1245,6 +1245,9 @@ config RTC_DRV_IMXDI
 config RTC_DRV_OMAP
         tristate "TI OMAP Real Time Clock"
         depends on ARCH_OMAP || ARCH_DAVINCI || COMPILE_TEST
+        depends on OF
+        depends on PINCTRL
+        select GENERIC_PINCONF
         help
           Say "yes" here to support the on chip real time clock
           present on TI OMAP1, AM33xx, DA8xx/OMAP-L13x, AM43xx and DRA7xx.
diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c
index cadac8e2aa6b..b04ea9b5ae67 100644
--- a/drivers/rtc/rtc-omap.c
+++ b/drivers/rtc/rtc-omap.c
@@ -13,19 +13,23 @@
  * 2 of the License, or (at your option) any later version.
  */
 
-#include <linux/kernel.h>
+#include <dt-bindings/gpio/gpio.h>
+#include <linux/bcd.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
 #include <linux/init.h>
-#include <linux/module.h>
+#include <linux/io.h>
 #include <linux/ioport.h>
-#include <linux/delay.h>
-#include <linux/rtc.h>
-#include <linux/bcd.h>
-#include <linux/platform_device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinconf-generic.h>
+#include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
-#include <linux/io.h>
-#include <linux/clk.h>
+#include <linux/rtc.h>
 
 /*
  * The OMAP RTC is a year/month/day/hours/minutes/seconds BCD clock
@@ -115,6 +119,8 @@
 
 /* OMAP_RTC_PMIC bit fields: */
 #define OMAP_RTC_PMIC_POWER_EN_EN       BIT(16)
+#define OMAP_RTC_PMIC_EXT_WKUP_EN(x)    BIT(x)
+#define OMAP_RTC_PMIC_EXT_WKUP_POL(x)   BIT(4 + x)
 
 /* OMAP_RTC_KICKER values */
 #define KICK0_VALUE                     0x83e70b13
@@ -141,6 +147,7 @@ struct omap_rtc {
         bool is_pmic_controller;
         bool has_ext_clk;
         const struct omap_rtc_device_type *type;
+        struct pinctrl_dev *pctldev;
 };
 
 static inline u8 rtc_read(struct omap_rtc *rtc, unsigned int reg)
@@ -525,6 +532,139 @@ static const struct of_device_id omap_rtc_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, omap_rtc_of_match);
 
+static const struct pinctrl_pin_desc rtc_pins_desc[] = {
+        PINCTRL_PIN(0, "ext_wakeup0"),
+        PINCTRL_PIN(1, "ext_wakeup1"),
+        PINCTRL_PIN(2, "ext_wakeup2"),
+        PINCTRL_PIN(3, "ext_wakeup3"),
+};
+
+static int rtc_pinctrl_get_groups_count(struct pinctrl_dev *pctldev)
+{
+        return 0;
+}
+
+static const char *rtc_pinctrl_get_group_name(struct pinctrl_dev *pctldev,
+                                        unsigned int group)
+{
+        return NULL;
+}
+
+static const struct pinctrl_ops rtc_pinctrl_ops = {
+        .get_groups_count = rtc_pinctrl_get_groups_count,
+        .get_group_name = rtc_pinctrl_get_group_name,
+        .dt_node_to_map = pinconf_generic_dt_node_to_map_pin,
+        .dt_free_map = pinconf_generic_dt_free_map,
+};
+
+enum rtc_pin_config_param {
+        PIN_CONFIG_ACTIVE_HIGH = PIN_CONFIG_END + 1,
+};
+
+static const struct pinconf_generic_params rtc_params[] = {
+        {"ti,active-high", PIN_CONFIG_ACTIVE_HIGH, 0},
+};
+
+#ifdef CONFIG_DEBUG_FS
+static const struct pin_config_item rtc_conf_items[ARRAY_SIZE(rtc_params)] = {
+        PCONFDUMP(PIN_CONFIG_ACTIVE_HIGH, "input active high", NULL, false),
+};
+#endif
+
+static int rtc_pinconf_get(struct pinctrl_dev *pctldev,
+                        unsigned int pin, unsigned long *config)
+{
+        struct omap_rtc *rtc = pinctrl_dev_get_drvdata(pctldev);
+        unsigned int param = pinconf_to_config_param(*config);
+        u32 val;
+        u16 arg = 0;
+
+        rtc->type->unlock(rtc);
+        val = rtc_readl(rtc, OMAP_RTC_PMIC_REG);
+        rtc->type->lock(rtc);
+
+        switch (param) {
+        case PIN_CONFIG_INPUT_ENABLE:
+                if (!(val & OMAP_RTC_PMIC_EXT_WKUP_EN(pin)))
+                        return -EINVAL;
+                break;
+        case PIN_CONFIG_ACTIVE_HIGH:
+                if (val & OMAP_RTC_PMIC_EXT_WKUP_POL(pin))
+                        return -EINVAL;
+                break;
+        default:
+                return -ENOTSUPP;
+        };
+
+        *config = pinconf_to_config_packed(param, arg);
+
+        return 0;
+}
+
+static int rtc_pinconf_set(struct pinctrl_dev *pctldev,
+                        unsigned int pin, unsigned long *configs,
+                        unsigned int num_configs)
+{
+        struct omap_rtc *rtc = pinctrl_dev_get_drvdata(pctldev);
+        u32 val;
+        unsigned int param;
+        u16 param_val;
+        int i;
+
+        rtc->type->unlock(rtc);
+        val = rtc_readl(rtc, OMAP_RTC_PMIC_REG);
+        rtc->type->lock(rtc);
+
+        /* active low by default */
+        val |= OMAP_RTC_PMIC_EXT_WKUP_POL(pin);
+
+        for (i = 0; i < num_configs; i++) {
+                param = pinconf_to_config_param(configs[i]);
+                param_val = pinconf_to_config_argument(configs[i]);
+
+                switch (param) {
+                case PIN_CONFIG_INPUT_ENABLE:
+                        if (param_val)
+                                val |= OMAP_RTC_PMIC_EXT_WKUP_EN(pin);
+                        else
+                                val &= ~OMAP_RTC_PMIC_EXT_WKUP_EN(pin);
+                        break;
+                case PIN_CONFIG_ACTIVE_HIGH:
+                        val &= ~OMAP_RTC_PMIC_EXT_WKUP_POL(pin);
+                        break;
+                default:
+                        dev_err(&rtc->rtc->dev, "Property %u not supported\n",
+                                param);
+                        return -ENOTSUPP;
+                }
+        }
+
+        rtc->type->unlock(rtc);
+        rtc_writel(rtc, OMAP_RTC_PMIC_REG, val);
+        rtc->type->lock(rtc);
+
+        return 0;
+}
+
+static const struct pinconf_ops rtc_pinconf_ops = {
+        .is_generic = true,
+        .pin_config_get = rtc_pinconf_get,
+        .pin_config_set = rtc_pinconf_set,
+};
+
+static struct pinctrl_desc rtc_pinctrl_desc = {
+        .pins = rtc_pins_desc,
+        .npins = ARRAY_SIZE(rtc_pins_desc),
+        .pctlops = &rtc_pinctrl_ops,
+        .confops = &rtc_pinconf_ops,
+        .custom_params = rtc_params,
+        .num_custom_params = ARRAY_SIZE(rtc_params),
+#ifdef CONFIG_DEBUG_FS
+        .custom_conf_items = rtc_conf_items,
+#endif
+        .owner = THIS_MODULE,
+};
+
 static int omap_rtc_probe(struct platform_device *pdev)
 {
         struct omap_rtc *rtc;
@@ -681,6 +821,15 @@ static int omap_rtc_probe(struct platform_device *pdev)
                 }
         }
 
+        /* Support ext_wakeup pinconf */
+        rtc_pinctrl_desc.name = dev_name(&pdev->dev);
+
+        rtc->pctldev = pinctrl_register(&rtc_pinctrl_desc, &pdev->dev, rtc);
+        if (IS_ERR(rtc->pctldev)) {
+                dev_err(&pdev->dev, "Couldn't register pinctrl driver\n");
+                return PTR_ERR(rtc->pctldev);
+        }
+
         return 0;
 
 err:
@@ -724,6 +873,9 @@ static int __exit omap_rtc_remove(struct platform_device *pdev)
         pm_runtime_put_sync(&pdev->dev);
         pm_runtime_disable(&pdev->dev);
 
+        /* Remove ext_wakeup pinconf */
+        pinctrl_unregister(rtc->pctldev);
+
         return 0;
 }