platform/x86/intel: bytcrc_pwrsrc: Optionally register a power_supply dev

On some Android tablets with Crystal Cove PMIC the DSDT lacks an ACPI AC
device to indicate whether a charger is plugged in or not.

Add support for registering a "crystal_cove_pwrsrc" power_supply class
device to indicate charger online status. This is made conditional on
a "linux,register-pwrsrc-power_supply" boolean device-property to avoid
registering a duplicate power_supply class device on devices where this
is already handled by an ACPI AC device.

Note the "linux,register-pwrsrc-power_supply" property is only used on
x86/ACPI (non devicetree) devs and the devicetree-bindings maintainers
have requested properties like these to not be added to the devicetree
bindings, so the new property is deliberately not added to any bindings.

Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20241204193442.65374-2-hdegoede@redhat.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

diff --git a/drivers/platform/x86/intel/bytcrc_pwrsrc.c b/drivers/platform/x86/intel/bytcrc_pwrsrc.c
index 3edc2a9dab388d26175eb855855754e6563c9f2a..68ac040082df8e775e906c10bbbc460a8734477b 100644 (file)
--- a/drivers/platform/x86/intel/bytcrc_pwrsrc.c
+++ b/drivers/platform/x86/intel/bytcrc_pwrsrc.c
@@ -8,13 +8,22 @@
  * Copyright (C) 2013 Intel Corporation
  */
 
+#include <linux/array_size.h>
+#include <linux/bits.h>
 #include <linux/debugfs.h>
+#include <linux/interrupt.h>
 #include <linux/mfd/intel_soc_pmic.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/property.h>
 #include <linux/regmap.h>
 
+#define CRYSTALCOVE_PWRSRC_IRQ         0x03
 #define CRYSTALCOVE_SPWRSRC_REG                0x1E
+#define CRYSTALCOVE_SPWRSRC_USB                BIT(0)
+#define CRYSTALCOVE_SPWRSRC_DC         BIT(1)
+#define CRYSTALCOVE_SPWRSRC_BATTERY    BIT(2)
 #define CRYSTALCOVE_RESETSRC0_REG      0x20
 #define CRYSTALCOVE_RESETSRC1_REG      0x21
 #define CRYSTALCOVE_WAKESRC_REG                0x22
@@ -22,6 +31,7 @@
 struct crc_pwrsrc_data {
        struct regmap *regmap;
        struct dentry *debug_dentry;
+       struct power_supply *psy;
        unsigned int resetsrc0;
        unsigned int resetsrc1;
        unsigned int wakesrc;
@@ -118,13 +128,60 @@ static int crc_pwrsrc_read_and_clear(struct crc_pwrsrc_data *data,
        return regmap_write(data->regmap, reg, *val);
 }
 
+static irqreturn_t crc_pwrsrc_irq_handler(int irq, void *_data)
+{
+       struct crc_pwrsrc_data *data = _data;
+       unsigned int irq_mask;
+
+       if (regmap_read(data->regmap, CRYSTALCOVE_PWRSRC_IRQ, &irq_mask))
+               return IRQ_NONE;
+
+       regmap_write(data->regmap, CRYSTALCOVE_PWRSRC_IRQ, irq_mask);
+
+       power_supply_changed(data->psy);
+       return IRQ_HANDLED;
+}
+
+static int crc_pwrsrc_psy_get_property(struct power_supply *psy,
+                                      enum power_supply_property psp,
+                                      union power_supply_propval *val)
+{
+       struct crc_pwrsrc_data *data = power_supply_get_drvdata(psy);
+       unsigned int pwrsrc;
+       int ret;
+
+       if (psp != POWER_SUPPLY_PROP_ONLINE)
+               return -EINVAL;
+
+       ret = regmap_read(data->regmap, CRYSTALCOVE_SPWRSRC_REG, &pwrsrc);
+       if (ret)
+               return ret;
+
+       val->intval = !!(pwrsrc & (CRYSTALCOVE_SPWRSRC_USB |
+                                  CRYSTALCOVE_SPWRSRC_DC));
+       return 0;
+}
+
+static const enum power_supply_property crc_pwrsrc_psy_props[] = {
+       POWER_SUPPLY_PROP_ONLINE,
+};
+
+static const struct power_supply_desc crc_pwrsrc_psy_desc = {
+       .name = "crystal_cove_pwrsrc",
+       .type = POWER_SUPPLY_TYPE_MAINS,
+       .properties = crc_pwrsrc_psy_props,
+       .num_properties = ARRAY_SIZE(crc_pwrsrc_psy_props),
+       .get_property = crc_pwrsrc_psy_get_property,
+};
+
 static int crc_pwrsrc_probe(struct platform_device *pdev)
 {
        struct intel_soc_pmic *pmic = dev_get_drvdata(pdev->dev.parent);
+       struct device *dev = &pdev->dev;
        struct crc_pwrsrc_data *data;
-       int ret;
+       int irq, ret;
 
-       data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+       data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;
 
@@ -149,6 +206,24 @@ static int crc_pwrsrc_probe(struct platform_device *pdev)
        if (ret)
                return ret;
 
+       if (device_property_read_bool(dev->parent, "linux,register-pwrsrc-power_supply")) {
+               struct power_supply_config psy_cfg = { .drv_data = data };
+
+               irq = platform_get_irq(pdev, 0);
+               if (irq < 0)
+                       return irq;
+
+               data->psy = devm_power_supply_register(dev, &crc_pwrsrc_psy_desc, &psy_cfg);
+               if (IS_ERR(data->psy))
+                       return dev_err_probe(dev, PTR_ERR(data->psy), "registering power-supply\n");
+
+               ret = devm_request_threaded_irq(dev, irq, NULL,
+                                               crc_pwrsrc_irq_handler,
+                                               IRQF_ONESHOT, KBUILD_MODNAME, data);
+               if (ret)
+                       return dev_err_probe(dev, ret, "requesting IRQ\n");
+       }
+
        data->debug_dentry = debugfs_create_dir(KBUILD_MODNAME, NULL);
        debugfs_create_file("pwrsrc", 0444, data->debug_dentry, data, &pwrsrc_fops);
        debugfs_create_file("resetsrc", 0444, data->debug_dentry, data, &resetsrc_fops);