From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D06AAC25B0E for ; Fri, 19 Aug 2022 07:56:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347278AbiHSH4f (ORCPT ); Fri, 19 Aug 2022 03:56:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51424 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347292AbiHSH43 (ORCPT ); Fri, 19 Aug 2022 03:56:29 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 905CF1834E for ; Fri, 19 Aug 2022 00:56:28 -0700 (PDT) Received: from ptx.hi.pengutronix.de ([2001:67c:670:100:1d::c0]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1oOwrZ-0000mt-EJ; Fri, 19 Aug 2022 09:56:17 +0200 Received: from mfe by ptx.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1oOwrY-0007gu-0D; Fri, 19 Aug 2022 09:56:16 +0200 Date: Fri, 19 Aug 2022 09:56:15 +0200 From: Marco Felsch To: Jacopo Mondi Cc: mchehab@kernel.org, sakari.ailus@linux.intel.com, laurent.pinchart+renesas@ideasonboard.com, jacopo+renesas@jmondi.org, akinobu.mita@gmail.com, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, kernel@pengutronix.de Subject: Re: [PATCH 1/4] media: mt9m111: add V4L2_CID_PIXEL_RATE support Message-ID: <20220819075615.a3nuakrac54kn7t3@pengutronix.de> References: <20220818144712.997477-1-m.felsch@pengutronix.de> <20220818161108.dlmi77o6j7wcyayc@uno.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220818161108.dlmi77o6j7wcyayc@uno.localdomain> User-Agent: NeoMutt/20180716 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c0 X-SA-Exim-Mail-From: mfe@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jacopo, On 22-08-18, Jacopo Mondi wrote: > Hi Marco > > On Thu, Aug 18, 2022 at 04:47:09PM +0200, Marco Felsch wrote: > > Add support to report the PIXEL_RATE so a host or bridge device can ask > > the sensor. > > > > Signed-off-by: Marco Felsch > > --- > > drivers/media/i2c/mt9m111.c | 15 ++++++++++++++- > > 1 file changed, 14 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/media/i2c/mt9m111.c b/drivers/media/i2c/mt9m111.c > > index afc86efa9e3e..cdaf283e1309 100644 > > --- a/drivers/media/i2c/mt9m111.c > > +++ b/drivers/media/i2c/mt9m111.c > > @@ -908,6 +908,8 @@ static int mt9m111_s_ctrl(struct v4l2_ctrl *ctrl) > > return mt9m111_set_test_pattern(mt9m111, ctrl->val); > > case V4L2_CID_COLORFX: > > return mt9m111_set_colorfx(mt9m111, ctrl->val); > > + case V4L2_CID_PIXEL_RATE: > > + return 0; > > By default PIXEL_RATE is read-only. > Do you get a call to s_ctrl for it ? You're absolutly right, we don't need to do this. > > } > > > > return -EINVAL; > > @@ -1249,6 +1251,7 @@ static int mt9m111_probe(struct i2c_client *client) > > { > > struct mt9m111 *mt9m111; > > struct i2c_adapter *adapter = client->adapter; > > + unsigned long mclk_rate; > > int ret; > > > > if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) { > > @@ -1271,6 +1274,13 @@ static int mt9m111_probe(struct i2c_client *client) > > if (IS_ERR(mt9m111->clk)) > > return PTR_ERR(mt9m111->clk); > > > > + ret = clk_prepare_enable(mt9m111->clk); > > + if (ret < 0) > > + return ret; > > + > > Do you need to enable clock to read its rate ? Yes, accroding the API [1]. [1] https://elixir.bootlin.com/linux/v6.0-rc1/source/include/linux/clk.h#L682 > > + mclk_rate = clk_get_rate(mt9m111->clk); > > + clk_disable_unprepare(mt9m111->clk); > > + > > mt9m111->regulator = devm_regulator_get(&client->dev, "vdd"); > > if (IS_ERR(mt9m111->regulator)) { > > dev_err(&client->dev, "regulator not found: %ld\n", > > @@ -1285,7 +1295,7 @@ static int mt9m111_probe(struct i2c_client *client) > > mt9m111->subdev.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE | > > V4L2_SUBDEV_FL_HAS_EVENTS; > > > > - v4l2_ctrl_handler_init(&mt9m111->hdl, 7); > > + v4l2_ctrl_handler_init(&mt9m111->hdl, 8); > > v4l2_ctrl_new_std(&mt9m111->hdl, &mt9m111_ctrl_ops, > > V4L2_CID_VFLIP, 0, 1, 1, 0); > > v4l2_ctrl_new_std(&mt9m111->hdl, &mt9m111_ctrl_ops, > > @@ -1309,6 +1319,9 @@ static int mt9m111_probe(struct i2c_client *client) > > BIT(V4L2_COLORFX_NEGATIVE) | > > BIT(V4L2_COLORFX_SOLARIZATION)), > > V4L2_COLORFX_NONE); > > + v4l2_ctrl_new_std(&mt9m111->hdl, &mt9m111_ctrl_ops, V4L2_CID_PIXEL_RATE, > > + mclk_rate, mclk_rate, 1, mclk_rate); > > + > > I don't have a datasheet but it seems a little weird that the mclk > frequency is the same as the pixel clock rate ? I see your confusion here. I can only speak for the MT9M131 device which is covered by this driver as well. This device is composed of a internal-sensor and a internal-isp. The internal-sensor is clocked by mclk/2 but the final image device/sensor output-fifo is clocked by mclk. There are options to devide the output clock as well, but these options are not enabled yet. So yes, the pixel clock rate == mclk rate. To avoid confusion I could rename the mclk_rate to extclk_rate but then clock request is not 100% correct since we are requesting a "mclk", this should be "extclk". Regards, Marco > > mt9m111->subdev.ctrl_handler = &mt9m111->hdl; > > if (mt9m111->hdl.error) { > > ret = mt9m111->hdl.error; > > -- > > 2.30.2 > > >