Merge tag 'v5.4.121' into 5.4-2.3.x-imx

This is the 5.4.121 stable release

Signed-off-by: Andrey Zhizhikin <andrey.zhizhikin@leica-geosystems.com>

2 files changed, 82 insertions, 6 deletions

diff --git a/drivers/input/touchscreen/elants_i2c.c b/drivers/input/touchscreen/elants_i2c.c
index d4ad24ea54c8..a51e7c85f581 100644
--- a/drivers/input/touchscreen/elants_i2c.c
+++ b/drivers/input/touchscreen/elants_i2c.c
@@ -36,6 +36,7 @@
 #include <linux/of.h>
 #include <linux/gpio/consumer.h>
 #include <linux/regulator/consumer.h>
+#include <linux/uuid.h>
 #include <asm/unaligned.h>
 
 /* Device, Driver information */
@@ -1127,6 +1128,40 @@ static void elants_i2c_power_off(void *_data)
 	}
 }
 
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id i2c_hid_ids[] = {
+	{"ACPI0C50", 0 },
+	{"PNP0C50", 0 },
+	{ },
+};
+
+static const guid_t i2c_hid_guid =
+	GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555,
+		  0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE);
+
+static bool elants_acpi_is_hid_device(struct device *dev)
+{
+	acpi_handle handle = ACPI_HANDLE(dev);
+	union acpi_object *obj;
+
+	if (acpi_match_device_ids(ACPI_COMPANION(dev), i2c_hid_ids))
+		return false;
+
+	obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL, ACPI_TYPE_INTEGER);
+	if (obj) {
+		ACPI_FREE(obj);
+		return true;
+	}
+
+	return false;
+}
+#else
+static bool elants_acpi_is_hid_device(struct device *dev)
+{
+	return false;
+}
+#endif
+
 static int elants_i2c_probe(struct i2c_client *client,
 			    const struct i2c_device_id *id)
 {
@@ -1135,9 +1170,14 @@ static int elants_i2c_probe(struct i2c_client *client,
 	unsigned long irqflags;
 	int error;
 
+	/* Don't bind to i2c-hid compatible devices, these are handled by the i2c-hid drv. */
+	if (elants_acpi_is_hid_device(&client->dev)) {
+		dev_warn(&client->dev, "This device appears to be an I2C-HID device, not binding\n");
+		return -ENODEV;
+	}
+
 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
-		dev_err(&client->dev,
-			"%s: i2c check functionality error\n", DEVICE_NAME);
+		dev_err(&client->dev, "I2C check functionality error\n");
 		return -ENXIO;
 	}
 
diff --git a/drivers/input/touchscreen/silead.c b/drivers/input/touchscreen/silead.c
index ad8b6a2bfd36..c8776146f1d1 100644
--- a/drivers/input/touchscreen/silead.c
+++ b/drivers/input/touchscreen/silead.c
@@ -20,6 +20,7 @@
 #include <linux/input/mt.h>
 #include <linux/input/touchscreen.h>
 #include <linux/pm.h>
+#include <linux/pm_runtime.h>
 #include <linux/irq.h>
 #include <linux/regulator/consumer.h>
 
@@ -335,10 +336,8 @@ static int silead_ts_get_id(struct i2c_client *client)
 
 	error = i2c_smbus_read_i2c_block_data(client, SILEAD_REG_ID,
 					      sizeof(chip_id), (u8 *)&chip_id);
-	if (error < 0) {
-		dev_err(&client->dev, "Chip ID read error %d\n", error);
+	if (error < 0)
 		return error;
-	}
 
 	data->chip_id = le32_to_cpu(chip_id);
 	dev_info(&client->dev, "Silead chip ID: 0x%8X", data->chip_id);
@@ -351,12 +350,49 @@ static int silead_ts_setup(struct i2c_client *client)
 	int error;
 	u32 status;
 
+	/*
+	 * Some buggy BIOS-es bring up the chip in a stuck state where it
+	 * blocks the I2C bus. The following steps are necessary to
+	 * unstuck the chip / bus:
+	 * 1. Turn off the Silead chip.
+	 * 2. Try to do an I2C transfer with the chip, this will fail in
+	 *    response to which the I2C-bus-driver will call:
+	 *    i2c_recover_bus() which will unstuck the I2C-bus. Note the
+	 *    unstuck-ing of the I2C bus only works if we first drop the
+	 *    chip off the bus by turning it off.
+	 * 3. Turn the chip back on.
+	 *
+	 * On the x86/ACPI systems were this problem is seen, step 1. and
+	 * 3. require making ACPI calls and dealing with ACPI Power
+	 * Resources. The workaround below runtime-suspends the chip to
+	 * turn it off, leaving it up to the ACPI subsystem to deal with
+	 * this.
+	 */
+
+	if (device_property_read_bool(&client->dev,
+				      "silead,stuck-controller-bug")) {
+		pm_runtime_set_active(&client->dev);
+		pm_runtime_enable(&client->dev);
+		pm_runtime_allow(&client->dev);
+
+		pm_runtime_suspend(&client->dev);
+
+		dev_warn(&client->dev, FW_BUG "Stuck I2C bus: please ignore the next 'controller timed out' error\n");
+		silead_ts_get_id(client);
+
+		/* The forbid will also resume the device */
+		pm_runtime_forbid(&client->dev);
+		pm_runtime_disable(&client->dev);
+	}
+
 	silead_ts_set_power(client, SILEAD_POWER_OFF);
 	silead_ts_set_power(client, SILEAD_POWER_ON);
 
 	error = silead_ts_get_id(client);
-	if (error)
+	if (error) {
+		dev_err(&client->dev, "Chip ID read error %d\n", error);
 		return error;
+	}
 
 	error = silead_ts_init(client);
 	if (error)