From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
To: Robin van der Gracht <robin@protonic.nl>
Cc: Miguel Ojeda Sandonis <miguel.ojeda.sandonis@gmail.com>,
Arnd Bergmann <arnd@arndb.de>,
Linus Walleij <linus.walleij@linaro.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Rob Herring <robh@kernel.org>,
linux-kernel@vger.kernel.org
Subject: [PATCH v2] auxdisplay: ht16k33: use le16_to_cpup() to fetch LE16 data
Date: Sat, 1 Apr 2017 10:27:14 -0700 [thread overview]
Message-ID: <20170401172714.GA23457@dtor-ws> (raw)
The data read from the device is 3 little-endian words, so let's
annotate them as such and use le16_to_cpu() to convert them to host
endianness - it might turn out to be a bit more performant, and it
expresses the conversion more clearly.
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
v2: do not compare result of i2c_smbus_read_i2c_block_data with
hard-coded value.
drivers/auxdisplay/ht16k33.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/drivers/auxdisplay/ht16k33.c b/drivers/auxdisplay/ht16k33.c
index f66b45b235b0..73f966434a2e 100644
--- a/drivers/auxdisplay/ht16k33.c
+++ b/drivers/auxdisplay/ht16k33.c
@@ -254,18 +254,22 @@ static bool ht16k33_keypad_scan(struct ht16k33_keypad *keypad)
{
const unsigned short *keycodes = keypad->dev->keycode;
u16 new_state[HT16K33_MATRIX_KEYPAD_MAX_COLS];
- u8 data[HT16K33_MATRIX_KEYPAD_MAX_COLS * 2];
+ __le16 data[HT16K33_MATRIX_KEYPAD_MAX_COLS];
unsigned long bits_changed;
int row, col, code;
+ int rc;
bool pressed = false;
- if (i2c_smbus_read_i2c_block_data(keypad->client, 0x40, 6, data) != 6) {
- dev_err(&keypad->client->dev, "Failed to read key data\n");
+ rc = i2c_smbus_read_i2c_block_data(keypad->client, 0x40,
+ sizeof(data), (u8 *)data);
+ if (rc != sizeof(data)) {
+ dev_err(&keypad->client->dev,
+ "Failed to read key data, rc=%d\n", rc);
return false;
}
for (col = 0; col < keypad->cols; col++) {
- new_state[col] = (data[col * 2 + 1] << 8) | data[col * 2];
+ new_state[col] = le16_to_cpu(data[col]);
if (new_state[col])
pressed = true;
bits_changed = keypad->last_key_state[col] ^ new_state[col];
--
2.12.2.564.g063fe858b8-goog
--
Dmitry
reply other threads:[~2017-04-01 17:27 UTC|newest]
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