1 files changed, 260 insertions, 89 deletions

diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index efbba0465eef..9601c0605fd9 100644
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
@@ -38,6 +38,8 @@
 #include <linux/mutex.h>
 #include <asm/unaligned.h>
 
+#include <drm/drm_panel.h>
+
 #include "../hid-ids.h"
 #include "i2c-hid.h"
 
@@ -107,6 +109,10 @@ struct i2c_hid {
 	struct mutex		reset_lock;
 
 	struct i2chid_ops	*ops;
+	struct drm_panel_follower panel_follower;
+	struct work_struct	panel_follower_prepare_work;
+	bool			is_panel_follower;
+	bool			prepare_work_finished;
 };
 
 static const struct i2c_hid_quirks {
@@ -855,7 +861,8 @@ static int i2c_hid_init_irq(struct i2c_client *client)
 		irqflags = IRQF_TRIGGER_LOW;
 
 	ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq,
-				   irqflags | IRQF_ONESHOT, client->name, ihid);
+				   irqflags | IRQF_ONESHOT | IRQF_NO_AUTOEN,
+				   client->name, ihid);
 	if (ret < 0) {
 		dev_warn(&client->dev,
 			"Could not register for %s interrupt, irq = %d,"
@@ -940,6 +947,239 @@ static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid)
 	ihid->ops->shutdown_tail(ihid->ops);
 }
 
+static int i2c_hid_core_suspend(struct i2c_hid *ihid, bool force_poweroff)
+{
+	struct i2c_client *client = ihid->client;
+	struct hid_device *hid = ihid->hid;
+	int ret;
+
+	ret = hid_driver_suspend(hid, PMSG_SUSPEND);
+	if (ret < 0)
+		return ret;
+
+	/* Save some power */
+	i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
+
+	disable_irq(client->irq);
+
+	if (force_poweroff || !device_may_wakeup(&client->dev))
+		i2c_hid_core_power_down(ihid);
+
+	return 0;
+}
+
+static int i2c_hid_core_resume(struct i2c_hid *ihid)
+{
+	struct i2c_client *client = ihid->client;
+	struct hid_device *hid = ihid->hid;
+	int ret;
+
+	if (!device_may_wakeup(&client->dev))
+		i2c_hid_core_power_up(ihid);
+
+	enable_irq(client->irq);
+
+	/* Instead of resetting device, simply powers the device on. This
+	 * solves "incomplete reports" on Raydium devices 2386:3118 and
+	 * 2386:4B33 and fixes various SIS touchscreens no longer sending
+	 * data after a suspend/resume.
+	 *
+	 * However some ALPS touchpads generate IRQ storm without reset, so
+	 * let's still reset them here.
+	 */
+	if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME)
+		ret = i2c_hid_hwreset(ihid);
+	else
+		ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
+
+	if (ret)
+		return ret;
+
+	return hid_driver_reset_resume(hid);
+}
+
+/**
+ * __do_i2c_hid_core_initial_power_up() - First time power up of the i2c-hid device.
+ * @ihid: The ihid object created during probe.
+ *
+ * This function is called at probe time.
+ *
+ * The initial power on is where we do some basic validation that the device
+ * exists, where we fetch the HID descriptor, and where we create the actual
+ * HID devices.
+ *
+ * Return: 0 or error code.
+ */
+static int __do_i2c_hid_core_initial_power_up(struct i2c_hid *ihid)
+{
+	struct i2c_client *client = ihid->client;
+	struct hid_device *hid = ihid->hid;
+	int ret;
+
+	ret = i2c_hid_core_power_up(ihid);
+	if (ret)
+		return ret;
+
+	/* Make sure there is something at this address */
+	ret = i2c_smbus_read_byte(client);
+	if (ret < 0) {
+		i2c_hid_dbg(ihid, "nothing at this address: %d\n", ret);
+		ret = -ENXIO;
+		goto err;
+	}
+
+	ret = i2c_hid_fetch_hid_descriptor(ihid);
+	if (ret < 0) {
+		dev_err(&client->dev,
+			"Failed to fetch the HID Descriptor\n");
+		goto err;
+	}
+
+	enable_irq(client->irq);
+
+	hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
+	hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
+	hid->product = le16_to_cpu(ihid->hdesc.wProductID);
+
+	hid->initial_quirks |= i2c_hid_get_dmi_quirks(hid->vendor,
+						      hid->product);
+
+	snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X",
+		 client->name, (u16)hid->vendor, (u16)hid->product);
+	strscpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
+
+	ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
+
+	ret = hid_add_device(hid);
+	if (ret) {
+		if (ret != -ENODEV)
+			hid_err(client, "can't add hid device: %d\n", ret);
+		goto err;
+	}
+
+	return 0;
+
+err:
+	i2c_hid_core_power_down(ihid);
+	return ret;
+}
+
+static void ihid_core_panel_prepare_work(struct work_struct *work)
+{
+	struct i2c_hid *ihid = container_of(work, struct i2c_hid,
+					    panel_follower_prepare_work);
+	struct hid_device *hid = ihid->hid;
+	int ret;
+
+	/*
+	 * hid->version is set on the first power up. If it's still zero then
+	 * this is the first power on so we should perform initial power up
+	 * steps.
+	 */
+	if (!hid->version)
+		ret = __do_i2c_hid_core_initial_power_up(ihid);
+	else
+		ret = i2c_hid_core_resume(ihid);
+
+	if (ret)
+		dev_warn(&ihid->client->dev, "Power on failed: %d\n", ret);
+	else
+		WRITE_ONCE(ihid->prepare_work_finished, true);
+
+	/*
+	 * The work APIs provide a number of memory ordering guarantees
+	 * including one that says that memory writes before schedule_work()
+	 * are always visible to the work function, but they don't appear to
+	 * guarantee that a write that happened in the work is visible after
+	 * cancel_work_sync(). We'll add a write memory barrier here to match
+	 * with i2c_hid_core_panel_unpreparing() to ensure that our write to
+	 * prepare_work_finished is visible there.
+	 */
+	smp_wmb();
+}
+
+static int i2c_hid_core_panel_prepared(struct drm_panel_follower *follower)
+{
+	struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower);
+
+	/*
+	 * Powering on a touchscreen can be a slow process. Queue the work to
+	 * the system workqueue so we don't block the panel's power up.
+	 */
+	WRITE_ONCE(ihid->prepare_work_finished, false);
+	schedule_work(&ihid->panel_follower_prepare_work);
+
+	return 0;
+}
+
+static int i2c_hid_core_panel_unpreparing(struct drm_panel_follower *follower)
+{
+	struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower);
+
+	cancel_work_sync(&ihid->panel_follower_prepare_work);
+
+	/* Match with ihid_core_panel_prepare_work() */
+	smp_rmb();
+	if (!READ_ONCE(ihid->prepare_work_finished))
+		return 0;
+
+	return i2c_hid_core_suspend(ihid, true);
+}
+
+static const struct drm_panel_follower_funcs i2c_hid_core_panel_follower_funcs = {
+	.panel_prepared = i2c_hid_core_panel_prepared,
+	.panel_unpreparing = i2c_hid_core_panel_unpreparing,
+};
+
+static int i2c_hid_core_register_panel_follower(struct i2c_hid *ihid)
+{
+	struct device *dev = &ihid->client->dev;
+	int ret;
+
+	ihid->is_panel_follower = true;
+	ihid->panel_follower.funcs = &i2c_hid_core_panel_follower_funcs;
+
+	/*
+	 * If we're not in control of our own power up/power down then we can't
+	 * do the logic to manage wakeups. Give a warning if a user thought
+	 * that was possible then force the capability off.
+	 */
+	if (device_can_wakeup(dev)) {
+		dev_warn(dev, "Can't wakeup if following panel\n");
+		device_set_wakeup_capable(dev, false);
+	}
+
+	ret = drm_panel_add_follower(dev, &ihid->panel_follower);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int i2c_hid_core_initial_power_up(struct i2c_hid *ihid)
+{
+	/*
+	 * If we're a panel follower, we'll register and do our initial power
+	 * up when the panel turns on; otherwise we do it right away.
+	 */
+	if (drm_is_panel_follower(&ihid->client->dev))
+		return i2c_hid_core_register_panel_follower(ihid);
+	else
+		return __do_i2c_hid_core_initial_power_up(ihid);
+}
+
+static void i2c_hid_core_final_power_down(struct i2c_hid *ihid)
+{
+	/*
+	 * If we're a follower, the act of unfollowing will cause us to be
+	 * powered down. Otherwise we need to manually do it.
+	 */
+	if (ihid->is_panel_follower)
+		drm_panel_remove_follower(&ihid->panel_follower);
+	else
+		i2c_hid_core_suspend(ihid, true);
+}
+
 int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
 		       u16 hid_descriptor_address, u32 quirks)
 {
@@ -966,48 +1206,27 @@ int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
 	if (!ihid)
 		return -ENOMEM;
 
-	ihid->ops = ops;
-
-	ret = i2c_hid_core_power_up(ihid);
-	if (ret)
-		return ret;
-
 	i2c_set_clientdata(client, ihid);
 
+	ihid->ops = ops;
 	ihid->client = client;
-
 	ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address);
 
 	init_waitqueue_head(&ihid->wait);
 	mutex_init(&ihid->reset_lock);
+	INIT_WORK(&ihid->panel_follower_prepare_work, ihid_core_panel_prepare_work);
 
 	/* we need to allocate the command buffer without knowing the maximum
 	 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the
 	 * real computation later. */
 	ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE);
 	if (ret < 0)
-		goto err_powered;
-
+		return ret;
 	device_enable_async_suspend(&client->dev);
 
-	/* Make sure there is something at this address */
-	ret = i2c_smbus_read_byte(client);
-	if (ret < 0) {
-		i2c_hid_dbg(ihid, "nothing at this address: %d\n", ret);
-		ret = -ENXIO;
-		goto err_powered;
-	}
-
-	ret = i2c_hid_fetch_hid_descriptor(ihid);
-	if (ret < 0) {
-		dev_err(&client->dev,
-			"Failed to fetch the HID Descriptor\n");
-		goto err_powered;
-	}
-
 	ret = i2c_hid_init_irq(client);
 	if (ret < 0)
-		goto err_powered;
+		goto err_buffers_allocated;
 
 	hid = hid_allocate_device();
 	if (IS_ERR(hid)) {
@@ -1021,26 +1240,11 @@ int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
 	hid->ll_driver = &i2c_hid_ll_driver;
 	hid->dev.parent = &client->dev;
 	hid->bus = BUS_I2C;
-	hid->version = le16_to_cpu(ihid->hdesc.bcdVersion);
-	hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
-	hid->product = le16_to_cpu(ihid->hdesc.wProductID);
-
 	hid->initial_quirks = quirks;
-	hid->initial_quirks |= i2c_hid_get_dmi_quirks(hid->vendor,
-						      hid->product);
-
-	snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X",
-		 client->name, (u16)hid->vendor, (u16)hid->product);
-	strscpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
-
-	ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product);
 
-	ret = hid_add_device(hid);
-	if (ret) {
-		if (ret != -ENODEV)
-			hid_err(client, "can't add hid device: %d\n", ret);
+	ret = i2c_hid_core_initial_power_up(ihid);
+	if (ret)
 		goto err_mem_free;
-	}
 
 	return 0;
 
@@ -1050,9 +1254,9 @@ err_mem_free:
 err_irq:
 	free_irq(client->irq, ihid);
 
-err_powered:
-	i2c_hid_core_power_down(ihid);
+err_buffers_allocated:
 	i2c_hid_free_buffers(ihid);
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(i2c_hid_core_probe);
@@ -1062,6 +1266,8 @@ void i2c_hid_core_remove(struct i2c_client *client)
 	struct i2c_hid *ihid = i2c_get_clientdata(client);
 	struct hid_device *hid;
 
+	i2c_hid_core_final_power_down(ihid);
+
 	hid = ihid->hid;
 	hid_destroy_device(hid);
 
@@ -1069,8 +1275,6 @@ void i2c_hid_core_remove(struct i2c_client *client)
 
 	if (ihid->bufsize)
 		i2c_hid_free_buffers(ihid);
-
-	i2c_hid_core_power_down(ihid);
 }
 EXPORT_SYMBOL_GPL(i2c_hid_core_remove);
 
@@ -1085,63 +1289,30 @@ void i2c_hid_core_shutdown(struct i2c_client *client)
 }
 EXPORT_SYMBOL_GPL(i2c_hid_core_shutdown);
 
-#ifdef CONFIG_PM_SLEEP
-static int i2c_hid_core_suspend(struct device *dev)
+static int i2c_hid_core_pm_suspend(struct device *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
 	struct i2c_hid *ihid = i2c_get_clientdata(client);
-	struct hid_device *hid = ihid->hid;
-	int ret;
-
-	ret = hid_driver_suspend(hid, PMSG_SUSPEND);
-	if (ret < 0)
-		return ret;
-
-	/* Save some power */
-	i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP);
 
-	disable_irq(client->irq);
-
-	if (!device_may_wakeup(&client->dev))
-		i2c_hid_core_power_down(ihid);
+	if (ihid->is_panel_follower)
+		return 0;
 
-	return 0;
+	return i2c_hid_core_suspend(ihid, false);
 }
 
-static int i2c_hid_core_resume(struct device *dev)
+static int i2c_hid_core_pm_resume(struct device *dev)
 {
-	int ret;
 	struct i2c_client *client = to_i2c_client(dev);
 	struct i2c_hid *ihid = i2c_get_clientdata(client);
-	struct hid_device *hid = ihid->hid;
-
-	if (!device_may_wakeup(&client->dev))
-		i2c_hid_core_power_up(ihid);
-
-	enable_irq(client->irq);
-
-	/* Instead of resetting device, simply powers the device on. This
-	 * solves "incomplete reports" on Raydium devices 2386:3118 and
-	 * 2386:4B33 and fixes various SIS touchscreens no longer sending
-	 * data after a suspend/resume.
-	 *
-	 * However some ALPS touchpads generate IRQ storm without reset, so
-	 * let's still reset them here.
-	 */
-	if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME)
-		ret = i2c_hid_hwreset(ihid);
-	else
-		ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON);
 
-	if (ret)
-		return ret;
+	if (ihid->is_panel_follower)
+		return 0;
 
-	return hid_driver_reset_resume(hid);
+	return i2c_hid_core_resume(ihid);
 }
-#endif
 
 const struct dev_pm_ops i2c_hid_core_pm = {
-	SET_SYSTEM_SLEEP_PM_OPS(i2c_hid_core_suspend, i2c_hid_core_resume)
+	SYSTEM_SLEEP_PM_OPS(i2c_hid_core_pm_suspend, i2c_hid_core_pm_resume)
 };
 EXPORT_SYMBOL_GPL(i2c_hid_core_pm);