In some cases it is possible for a device to be in its bootloader at
driver probe time. This is detected by the driver when probe() is called
with an i2c_client which has one of the Atmel Bootloader i2c addresses.
In this case, we should load enough driver functionality to still loading
new firmware using:
echo 1 > update_fw
However, we must be very careful not to follow any code paths that would try
to access the as-yet uninitialized object table or input device.
In particular:
1) mxt_remove calls input_unregister_device on input_dev.
2) mxt_suspend/resume reads and writes from the object table.
3) Spurious or bootloader induced interrupts
Signed-off-by: Benson Leung <ble...@chromium.org>
Signed-off-by: Daniel Kurtz <djku...@chromium.org>
---
drivers/input/touchscreen/atmel_mxt_ts.c | 51 +++++++++++++++++++++++++-------
1 file changed, 40 insertions(+), 11 deletions(-)
diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c
b/drivers/input/touchscreen/atmel_mxt_ts.c
index 9afc26e..6c2c712 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -324,6 +324,12 @@ static void mxt_dump_message(struct device *dev,
message->reportid, 7, message->message);
}
+static bool mxt_in_bootloader(struct mxt_data *data)
+{
+ struct i2c_client *client = data->client;
+ return (client->addr == MXT_BOOT_LOW || client->addr == MXT_BOOT_HIGH);
+}
+
static int mxt_i2c_recv(struct i2c_client *client, u8 *buf, size_t count)
{
int ret;
@@ -584,6 +590,9 @@ static irqreturn_t mxt_interrupt(int irq, void *dev_id)
u8 reportid;
bool update_input = false;
+ if (mxt_in_bootloader(data))
+ goto end;
+
do {
if (mxt_read_message(data, &message)) {
dev_err(dev, "Failed to read message\n");
@@ -975,6 +984,9 @@ static int mxt_load_fw(struct device *dev, const char *fn)
return ret;
}
+ if (mxt_in_bootloader(data))
+ goto bootloader_ready;
+
/* Change to the bootloader mode */
mxt_write_object(data, MXT_GEN_COMMAND_T6,
MXT_COMMAND_RESET, MXT_BOOT_VALUE);
@@ -986,6 +998,7 @@ static int mxt_load_fw(struct device *dev, const char *fn)
else
client->addr = MXT_BOOT_HIGH;
+bootloader_ready:
ret = mxt_check_bootloader(client, MXT_WAITING_BOOTLOAD_CMD);
if (ret)
goto out;
@@ -1196,25 +1209,34 @@ static int __devinit mxt_probe(struct i2c_client
*client,
mxt_calc_resolution(data);
- error = mxt_initialize(data);
- if (error)
- goto err_free_mem;
+ if (mxt_in_bootloader(data)) {
+ dev_info(&client->dev, "Device in bootloader at probe\n");
+ } else {
+ error = mxt_initialize(data);
+ if (error)
+ goto err_free_mem;
- error = mxt_input_dev_create(data);
- if (error)
- goto err_free_object;
+ error = mxt_input_dev_create(data);
+ if (error)
+ goto err_free_object;
+ }
error = request_threaded_irq(client->irq, NULL, mxt_interrupt,
pdata->irqflags | IRQF_ONESHOT,
client->name, data);
if (error) {
dev_err(&client->dev, "Failed to register interrupt\n");
- goto err_unregister_device;
+ if (mxt_in_bootloader(data))
+ goto err_free_mem;
+ else
+ goto err_unregister_device;
}
- error = mxt_make_highchg(data);
- if (error)
- goto err_free_irq;
+ if (!mxt_in_bootloader(data)) {
+ error = mxt_make_highchg(data);
+ if (error)
+ goto err_free_irq;
+ }
error = sysfs_create_group(&client->dev.kobj, &mxt_attr_group);
if (error)
@@ -1239,7 +1261,8 @@ static int mxt_remove(struct i2c_client *client)
sysfs_remove_group(&client->dev.kobj, &mxt_attr_group);
free_irq(data->irq, data);
- input_unregister_device(data->input_dev);
+ if (data->input_dev)
+ input_unregister_device(data->input_dev);
kfree(data->object_table);
kfree(data);
@@ -1253,6 +1276,9 @@ static int mxt_suspend(struct device *dev)
struct mxt_data *data = i2c_get_clientdata(client);
struct input_dev *input_dev = data->input_dev;
+ if (mxt_in_bootloader(data))
+ return 0;
+
mutex_lock(&input_dev->mutex);
if (input_dev->users)
@@ -1269,6 +1295,9 @@ static int mxt_resume(struct device *dev)
struct mxt_data *data = i2c_get_clientdata(client);
struct input_dev *input_dev = data->input_dev;
+ if (mxt_in_bootloader(data))
+ return 0;
+
/* Soft reset */
mxt_write_object(data, MXT_GEN_COMMAND_T6,
MXT_COMMAND_RESET, 1);
--
1.8.1
--
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