From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-wm0-f66.google.com ([74.125.82.66]:32771 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751554AbdBSS3K (ORCPT ); Sun, 19 Feb 2017 13:29:10 -0500 Received: by mail-wm0-f66.google.com with SMTP id v77so10799650wmv.0 for ; Sun, 19 Feb 2017 10:29:09 -0800 (PST) From: =?UTF-8?q?Frank=20Sch=C3=A4fer?= To: linux-media@vger.kernel.org Cc: mchehab@kernel.org, arnd@arndb.de, =?UTF-8?q?Frank=20Sch=C3=A4fer?= Subject: [PATCH 2/2] em28xx: simplify ID-reading from Micron sensors Date: Sun, 19 Feb 2017 19:29:18 +0100 Message-Id: <20170219182918.4978-2-fschaefer.oss@googlemail.com> In-Reply-To: <20170219182918.4978-1-fschaefer.oss@googlemail.com> References: <20170219182918.4978-1-fschaefer.oss@googlemail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-media-owner@vger.kernel.org List-ID: Use i2c_smbus_read_word_data() instead of i2c_master_send() and i2c_master_recv() for reading the ID of Micorn sensors. Bytes need to be swapped afterwards, because i2c_smbus_read_word_data() assumes that the received bytes are little-endian byte order (as specified by smbus), while Micron sensors with 16 bit register width use big endian byte order. Signed-off-by: Frank Schäfer --- drivers/media/usb/em28xx/em28xx-camera.c | 28 ++++------------------------ 1 file changed, 4 insertions(+), 24 deletions(-) diff --git a/drivers/media/usb/em28xx/em28xx-camera.c b/drivers/media/usb/em28xx/em28xx-camera.c index 7b4129ab1cf9..4839479624e7 100644 --- a/drivers/media/usb/em28xx/em28xx-camera.c +++ b/drivers/media/usb/em28xx/em28xx-camera.c @@ -106,8 +106,6 @@ static int em28xx_probe_sensor_micron(struct em28xx *dev) { int ret, i; char *name; - u8 reg; - __be16 id_be; u16 id; struct i2c_client *client = &dev->i2c_client[dev->def_i2c_bus]; @@ -115,10 +113,8 @@ static int em28xx_probe_sensor_micron(struct em28xx *dev) dev->em28xx_sensor = EM28XX_NOSENSOR; for (i = 0; micron_sensor_addrs[i] != I2C_CLIENT_END; i++) { client->addr = micron_sensor_addrs[i]; - /* NOTE: i2c_smbus_read_word_data() doesn't work with BE data */ /* Read chip ID from register 0x00 */ - reg = 0x00; - ret = i2c_master_send(client, ®, 1); + ret = i2c_smbus_read_word_data(client, 0x00); /* assumes LE */ if (ret < 0) { if (ret != -ENXIO) dev_err(&dev->intf->dev, @@ -126,24 +122,9 @@ static int em28xx_probe_sensor_micron(struct em28xx *dev) client->addr << 1, ret); continue; } - ret = i2c_master_recv(client, (u8 *)&id_be, 2); - if (ret < 0) { - dev_err(&dev->intf->dev, - "couldn't read from i2c device 0x%02x: error %i\n", - client->addr << 1, ret); - continue; - } - id = be16_to_cpu(id_be); + id = swab16(ret); /* LE -> BE */ /* Read chip ID from register 0xff */ - reg = 0xff; - ret = i2c_master_send(client, ®, 1); - if (ret < 0) { - dev_err(&dev->intf->dev, - "couldn't read from i2c device 0x%02x: error %i\n", - client->addr << 1, ret); - continue; - } - ret = i2c_master_recv(client, (u8 *)&id_be, 2); + ret = i2c_smbus_read_word_data(client, 0xff); if (ret < 0) { dev_err(&dev->intf->dev, "couldn't read from i2c device 0x%02x: error %i\n", @@ -151,10 +132,9 @@ static int em28xx_probe_sensor_micron(struct em28xx *dev) continue; } /* Validate chip ID to be sure we have a Micron device */ - if (id != be16_to_cpu(id_be)) + if (id != swab16(ret)) continue; /* Check chip ID */ - id = be16_to_cpu(id_be); switch (id) { case 0x1222: name = "MT9V012"; /* MI370 */ /* 640x480 */ -- 2.11.0