From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx07-00178001.pphosted.com ([62.209.51.94]:35323 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754100AbdK2RLl (ORCPT ); Wed, 29 Nov 2017 12:11:41 -0500 From: Hugues Fruchet To: Steve Longerbeam , Sakari Ailus , Hans Verkuil , "Mauro Carvalho Chehab" CC: , Hugues Fruchet , Benjamin Gaignard Subject: [PATCH v2 2/4] media: ov5640: check chip id Date: Wed, 29 Nov 2017 18:11:10 +0100 Message-ID: <1511975472-26659-3-git-send-email-hugues.fruchet@st.com> In-Reply-To: <1511975472-26659-1-git-send-email-hugues.fruchet@st.com> References: <1511975472-26659-1-git-send-email-hugues.fruchet@st.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-media-owner@vger.kernel.org List-ID: Verify that chip identifier is correct before starting streaming Signed-off-by: Hugues Fruchet --- drivers/media/i2c/ov5640.c | 30 +++++++++++++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-) diff --git a/drivers/media/i2c/ov5640.c b/drivers/media/i2c/ov5640.c index 61071f5..a576d11 100644 --- a/drivers/media/i2c/ov5640.c +++ b/drivers/media/i2c/ov5640.c @@ -34,7 +34,8 @@ #define OV5640_DEFAULT_SLAVE_ID 0x3c -#define OV5640_REG_CHIP_ID 0x300a +#define OV5640_REG_CHIP_ID_HIGH 0x300a +#define OV5640_REG_CHIP_ID_LOW 0x300b #define OV5640_REG_PAD_OUTPUT00 0x3019 #define OV5640_REG_SC_PLL_CTRL0 0x3034 #define OV5640_REG_SC_PLL_CTRL1 0x3035 @@ -926,6 +927,29 @@ static int ov5640_load_regs(struct ov5640_dev *sensor, return ret; } +static int ov5640_check_chip_id(struct ov5640_dev *sensor) +{ + struct i2c_client *client = sensor->i2c_client; + int ret; + u8 chip_id_h, chip_id_l; + + ret = ov5640_read_reg(sensor, OV5640_REG_CHIP_ID_HIGH, &chip_id_h); + if (ret) + return ret; + + ret = ov5640_read_reg(sensor, OV5640_REG_CHIP_ID_LOW, &chip_id_l); + if (ret) + return ret; + + if (!(chip_id_h == 0x56 && chip_id_l == 0x40)) { + dev_err(&client->dev, "%s: wrong chip identifier, expected 0x5640, got 0x%x%x\n", + __func__, chip_id_h, chip_id_l); + return -EINVAL; + } + + return 0; +} + /* read exposure, in number of line periods */ static int ov5640_get_exposure(struct ov5640_dev *sensor) { @@ -1562,6 +1586,10 @@ static int ov5640_set_power(struct ov5640_dev *sensor, bool on) ov5640_reset(sensor); ov5640_power(sensor, true); + ret = ov5640_check_chip_id(sensor); + if (ret) + goto power_off; + ret = ov5640_init_slave_id(sensor); if (ret) goto power_off; -- 1.9.1