[PATCH v6 4/4] HID: playstation: DualSense set LEDs to default player id.

[Roderick Colenbrander <roderick@gaikai.com>]

From: Roderick Colenbrander <roderick.colenbrander@sony.com>

Add a ID allocator to assign player ids to ps_device instances.
Utilize the player id to set a default color on the DualSense its
player LED strip.

Signed-off-by: Roderick Colenbrander <roderick.colenbrander@sony.com>
---
 drivers/hid/hid-playstation.c | 70 ++++++++++++++++++++++++++++++++++-
 1 file changed, 69 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-playstation.c b/drivers/hid/hid-playstation.c
index 2d96785c397d..973c1fe61e8a 100644
--- a/drivers/hid/hid-playstation.c
+++ b/drivers/hid/hid-playstation.c
@@ -9,6 +9,7 @@
 #include <linux/crc32.h>
 #include <linux/device.h>
 #include <linux/hid.h>
+#include <linux/idr.h>
 #include <linux/input/mt.h>
 #include <linux/leds.h>
 #include <linux/led-class-multicolor.h>
@@ -22,6 +23,8 @@
 static DEFINE_MUTEX(ps_devices_lock);
 static LIST_HEAD(ps_devices_list);
 
+static DEFINE_IDA(ps_player_id_allocator);
+
 #define HID_PLAYSTATION_VERSION_PATCH 0x8000
 
 /* Base class for playstation devices. */
@@ -30,6 +33,8 @@ struct ps_device {
 	struct hid_device *hdev;
 	spinlock_t lock;
 
+	uint32_t player_id;
+
 	struct power_supply_desc battery_desc;
 	struct power_supply *battery;
 	uint8_t battery_capacity;
@@ -321,6 +326,24 @@ static int ps_devices_list_remove(struct ps_device *dev)
 	return 0;
 }
 
+static int ps_device_set_player_id(struct ps_device *dev)
+{
+	int ret = ida_alloc(&ps_player_id_allocator, GFP_KERNEL);
+
+	if (ret < 0)
+		return ret;
+
+	dev->player_id = ret;
+	return 0;
+}
+
+static void ps_device_release_player_id(struct ps_device *dev)
+{
+	ida_free(&ps_player_id_allocator, dev->player_id);
+
+	dev->player_id = U32_MAX;
+}
+
 static struct input_dev *ps_allocate_input_dev(struct hid_device *hdev, const char *name_suffix)
 {
 	struct input_dev *input_dev;
@@ -1156,6 +1179,29 @@ static int dualsense_reset_leds(struct dualsense *ds)
 	return 0;
 }
 
+static void dualsense_set_player_leds(struct dualsense *ds)
+{
+	/*
+	 * The DualSense controller has a row of 5 LEDs used for player ids.
+	 * Behavior on the PlayStation 5 console is to center the player id
+	 * across the LEDs, so e.g. player 1 would be "--x--" with x being 'on'.
+	 * Follow a similar mapping here.
+	 */
+	static const int player_ids[5] = {
+		BIT(2),
+		BIT(3) | BIT(1),
+		BIT(4) | BIT(2) | BIT(0),
+		BIT(4) | BIT(3) | BIT(1) | BIT(0),
+		BIT(4) | BIT(3) | BIT(2) | BIT(1) | BIT(0)
+	};
+
+	uint8_t player_id = ds->base.player_id % ARRAY_SIZE(player_ids);
+
+	ds->update_player_leds = true;
+	ds->player_leds_state = player_ids[player_id];
+	schedule_work(&ds->output_worker);
+}
+
 static struct ps_device *dualsense_create(struct hid_device *hdev)
 {
 	struct dualsense *ds;
@@ -1264,6 +1310,15 @@ static struct ps_device *dualsense_create(struct hid_device *hdev)
 			goto err;
 	}
 
+	ret = ps_device_set_player_id(ps_dev);
+	if (ret) {
+		hid_err(hdev, "Failed to assign player id for DualSense: %d\n", ret);
+		goto err;
+	}
+
+	/* Set player LEDs to our player id. */
+	dualsense_set_player_leds(ds);
+
 	return &ds->base;
 
 err:
@@ -1328,6 +1383,7 @@ static void ps_remove(struct hid_device *hdev)
 	struct ps_device *dev = hid_get_drvdata(hdev);
 
 	ps_devices_list_remove(dev);
+	ps_device_release_player_id(dev);
 
 	hid_hw_close(hdev);
 	hid_hw_stop(hdev);
@@ -1348,7 +1404,19 @@ static struct hid_driver ps_driver = {
 	.raw_event	= ps_raw_event,
 };
 
-module_hid_driver(ps_driver);
+static int __init ps_init(void)
+{
+	return hid_register_driver(&ps_driver);
+}
+
+static void __exit ps_exit(void)
+{
+	hid_unregister_driver(&ps_driver);
+	ida_destroy(&ps_player_id_allocator);
+}
+
+module_init(ps_init);
+module_exit(ps_exit);
 
 MODULE_AUTHOR("Sony Interactive Entertainment");
 MODULE_DESCRIPTION("HID Driver for PlayStation peripherals.");
-- 
2.26.2