From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751969AbdJDKrW (ORCPT ); Wed, 4 Oct 2017 06:47:22 -0400 Received: from galahad.ideasonboard.com ([185.26.127.97]:57374 "EHLO galahad.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751440AbdJDKrU (ORCPT ); Wed, 4 Oct 2017 06:47:20 -0400 From: Laurent Pinchart To: Sakari Ailus Cc: Todor Tomov , mchehab@kernel.org, hansverk@cisco.com, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org, Wolfram Sang Subject: Re: [PATCH] [media] ov5645: I2C address change Date: Wed, 04 Oct 2017 13:47:22 +0300 Message-ID: <3073637.dhNDna4gKQ@avalon> In-Reply-To: <20171004103008.g7azpn4a3hfj4fs2@valkosipuli.retiisi.org.uk> References: <1506950925-13924-1-git-send-email-todor.tomov@linaro.org> <20171004103008.g7azpn4a3hfj4fs2@valkosipuli.retiisi.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id v94AlRfL016624 CC'ing the I2C mainling list and the I2C maintainer. On Wednesday, 4 October 2017 13:30:08 EEST Sakari Ailus wrote: > Hi Todor, > > On Mon, Oct 02, 2017 at 04:28:45PM +0300, Todor Tomov wrote: > > As soon as the sensor is powered on, change the I2C address to the one > > specified in DT. This allows to use multiple physical sensors connected > > to the same I2C bus. > > > > Signed-off-by: Todor Tomov > > The smiapp driver does something similar and I understand Laurent might be > interested in such functionality as well. > > It'd be nice to handle this through the I²C framework instead and to define > how the information is specified through DT. That way it could be made > generic, to work with more devices than just this one. > > What do you think? > > Cc Laurent. > > > --- > > > > drivers/media/i2c/ov5645.c | 42 ++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 42 insertions(+) > > > > diff --git a/drivers/media/i2c/ov5645.c b/drivers/media/i2c/ov5645.c > > index d28845f..8541109 100644 > > --- a/drivers/media/i2c/ov5645.c > > +++ b/drivers/media/i2c/ov5645.c > > @@ -33,6 +33,7 @@ > > #include > > #include > > #include > > +#include > > #include > > #include > > #include > > @@ -42,6 +43,8 @@ > > #include > > #include > > > > +static DEFINE_MUTEX(ov5645_lock); > > + > > #define OV5645_VOLTAGE_ANALOG 2800000 > > #define OV5645_VOLTAGE_DIGITAL_CORE 1500000 > > #define OV5645_VOLTAGE_DIGITAL_IO 1800000 > > @@ -590,6 +593,31 @@ static void ov5645_regulators_disable(struct ov5645 > > *ov5645) > > dev_err(ov5645->dev, "io regulator disable failed\n"); > > } > > > > +static int ov5645_write_reg_to(struct ov5645 *ov5645, u16 reg, u8 val, > > + u16 i2c_addr) > > +{ > > + u8 regbuf[3] = { > > + reg >> 8, > > + reg & 0xff, > > + val > > + }; > > + struct i2c_msg msgs = { > > + .addr = i2c_addr, > > + .flags = 0, > > + .len = 3, > > + .buf = regbuf > > + }; > > + int ret; > > + > > + ret = i2c_transfer(ov5645->i2c_client->adapter, &msgs, 1); > > + if (ret < 0) > > + dev_err(ov5645->dev, > > + "%s: write reg error %d on addr 0x%x: reg=0x%x, val=0x%x\n", > > + __func__, ret, i2c_addr, reg, val); > > + > > + return ret; > > +} > > + > > static int ov5645_write_reg(struct ov5645 *ov5645, u16 reg, u8 val) > > { > > u8 regbuf[3]; > > @@ -729,10 +757,24 @@ static int ov5645_s_power(struct v4l2_subdev *sd, > > int on) > > */ > > if (ov5645->power_count == !on) { > > if (on) { > > + mutex_lock(&ov5645_lock); > > + > > ret = ov5645_set_power_on(ov5645); > > if (ret < 0) > > goto exit; > > > > + ret = ov5645_write_reg_to(ov5645, 0x3100, > > + ov5645->i2c_client->addr, 0x78); > > + if (ret < 0) { > > + dev_err(ov5645->dev, > > + "could not change i2c address\n"); > > + ov5645_set_power_off(ov5645); > > + mutex_unlock(&ov5645_lock); > > + goto exit; > > + } > > + > > + mutex_unlock(&ov5645_lock); > > + > > ret = ov5645_set_register_array(ov5645, > > ov5645_global_init_setting, > > ARRAY_SIZE(ov5645_global_init_setting)); -- Regards, Laurent Pinchart