[PATCH 5/9] HID: i2c-hid: Rearrange probe() to power things up later

Douglas Anderson
2023-05-23T19:32:03Z

In a future patch, we want to change i2c-hid not to necessarily power
up the touchscreen during probe. In preparation for that, rearrange
the probe function so that we put as much stuff _before_ powering up
the device as possible.

This change is expected to have no functional effect.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
---

drivers/hid/i2c-hid/i2c-hid-core.c | 124 ++++++++++++++++++-----------
1 file changed, 77 insertions(+), 47 deletions(-)

diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index 19d985c20a5c..fb5ebf3ca739 100644
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
@@ -855,7 +855,8 @@ 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 +941,72 @@ static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid)
ihid->ops->shutdown_tail(ihid->ops);
}

+/**
+ * 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.
+ */
+int 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;
+}
+
int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
u16 hid_descriptor_address, u32 quirks)
{
@@ -966,16 +1033,10 @@ 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);
@@ -986,28 +1047,12 @@ int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
* 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 +1066,11 @@ 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 +1080,9 @@ int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
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 +1092,8 @@ void i2c_hid_core_remove(struct i2c_client *client)
struct i2c_hid *ihid = i2c_get_clientdata(client);
struct hid_device *hid;

+ i2c_hid_core_power_down(ihid);
+
hid = ihid->hid;
hid_destroy_device(hid);

@@ -1069,8 +1101,6 @@ 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);

--
2.40.1.698.g37aff9b760-goog