[openwrt/openwrt] mediatek: support reading more than one byte of response

[LEDE Commits]

dangole pushed a commit to openwrt/openwrt.git, branch openwrt-22.03:
https://git.openwrt.org/b5665a004526aff62b07d7c729f8ef9e9d98a8e7

commit b5665a004526aff62b07d7c729f8ef9e9d98a8e7
Author: Sven Wegener <sven.wegener at stealer.net>
AuthorDate: Sat Jun 12 21:56:21 2021 +0200

    mediatek: support reading more than one byte of response
    
    There are commands that return more than one byte of response.
    
    Signed-off-by: Sven Wegener <sven.wegener at stealer.net>
    (cherry picked from commit 7c852e7df50e370b26b060c96c3cc4491cee88eb)
---
 .../mediatek/files-5.10/drivers/leds/leds-ubnt-ledbar.c   | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/target/linux/mediatek/files-5.10/drivers/leds/leds-ubnt-ledbar.c b/target/linux/mediatek/files-5.10/drivers/leds/leds-ubnt-ledbar.c
index 8168391d7e..c62e233e6d 100644
--- a/target/linux/mediatek/files-5.10/drivers/leds/leds-ubnt-ledbar.c
+++ b/target/linux/mediatek/files-5.10/drivers/leds/leds-ubnt-ledbar.c
@@ -41,16 +41,17 @@ struct ubnt_ledbar {
 	struct gpio_desc *enable_gpio;
 };
 
-static int ubnt_ledbar_perform_transaction(struct ubnt_ledbar *ledbar,
-					   char *transaction)
+static void ubnt_ledbar_perform_transaction(struct ubnt_ledbar *ledbar,
+					   const char *transaction, int len,
+					   char *result, int result_len)
 {
-	int ret;
 	int i;
 
-	for (i = 0; i < UBNT_LEDBAR_TRANSACTION_LENGTH; i++)
+	for (i = 0; i < len; i++)
 		i2c_smbus_write_byte(ledbar->client, transaction[i]);
 
-	return i2c_smbus_read_byte(ledbar->client);
+	for (i = 0; i < result_len; i++)
+		result[i] = i2c_smbus_read_byte(ledbar->client);
 }
 
 static int ubnt_ledbar_apply_state(struct ubnt_ledbar *ledbar)
@@ -72,14 +73,14 @@ static int ubnt_ledbar_apply_state(struct ubnt_ledbar *ledbar)
 
 	msleep(10);
 
-	i2c_response = ubnt_ledbar_perform_transaction(ledbar, setup_msg);
+	ubnt_ledbar_perform_transaction(ledbar, setup_msg, sizeof(setup_msg), &i2c_response, sizeof(i2c_response));
 	if (i2c_response != UBNT_LEDBAR_TRANSACTION_SUCCESS) {
 		dev_err(&ledbar->client->dev, "Error initializing LED transaction: %02hhx\n", i2c_response);
 		ret = -EINVAL;
 		goto out_gpio;
 	}
 
-	i2c_response = ubnt_ledbar_perform_transaction(ledbar, led_msg);
+	ubnt_ledbar_perform_transaction(ledbar, led_msg, sizeof(led_msg), &i2c_response, sizeof(i2c_response));
 	if (i2c_response != UBNT_LEDBAR_TRANSACTION_SUCCESS) {
 		dev_err(&ledbar->client->dev, "Failed LED transaction: %02hhx\n", i2c_response);
 		ret = -EINVAL;