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 X-Spam-Level: X-Spam-Status: No, score=-6.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE05DC433E0 for ; Thu, 18 Jun 2020 15:51:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C6D0D20732 for ; Thu, 18 Jun 2020 15:51:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731596AbgFRPv3 (ORCPT ); Thu, 18 Jun 2020 11:51:29 -0400 Received: from relay9-d.mail.gandi.net ([217.70.183.199]:38095 "EHLO relay9-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729009AbgFRPv0 (ORCPT ); Thu, 18 Jun 2020 11:51:26 -0400 X-Originating-IP: 93.34.118.233 Received: from uno.localdomain (93-34-118-233.ip49.fastwebnet.it [93.34.118.233]) (Authenticated sender: jacopo@jmondi.org) by relay9-d.mail.gandi.net (Postfix) with ESMTPSA id 4626FFF809; Thu, 18 Jun 2020 15:51:18 +0000 (UTC) Date: Thu, 18 Jun 2020 17:54:43 +0200 From: Jacopo Mondi To: Roman Kovalivskyi Cc: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Luis Oliveira , Niklas =?utf-8?Q?S=C3=B6derlund?= , Michael Rodin , Mauro Carvalho Chehab , Sakari Ailus , Hugues Fruchet , Maxime Ripard , Adam Ford , Todor Tomov , Suresh Udipi , Andrew Gabbasov , Eugeniu Rosca , Dave Stevenson Subject: Re: [PATCH v2 2/6] media: ov5647: Add support for PWDN GPIO. Message-ID: <20200618155443.qahjxvlsqckmrgnw@uno.localdomain> References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Roman, On Tue, May 19, 2020 at 04:16:17AM +0300, Roman Kovalivskyi wrote: > From: Dave Stevenson > > Add support for an optional GPIO connected to PWDN on the sensor. This > allows the use of hardware standby mode where internal device clock > and circuit activities are halted. > > Please nothe that power is off when PWDN is high. > > Signed-off-by: Dave Stevenson > Signed-off-by: Roman Kovalivskyi > --- > drivers/media/i2c/ov5647.c | 33 +++++++++++++++++++++++++++++++++ > 1 file changed, 33 insertions(+) > > diff --git a/drivers/media/i2c/ov5647.c b/drivers/media/i2c/ov5647.c > index 3e587eb0a30e..796cc80f8ee1 100644 > --- a/drivers/media/i2c/ov5647.c > +++ b/drivers/media/i2c/ov5647.c > @@ -21,6 +21,7 @@ > > #include > #include > +#include > #include > #include > #include > @@ -35,6 +36,13 @@ > > #define SENSOR_NAME "ov5647" > > +/* > + * From the datasheet, "20ms after PWDN goes low or 20ms after RESETB goes > + * high if reset is inserted after PWDN goes high, host can access sensor's > + * SCCB to initialize sensor." > + */ > +#define PWDN_ACTIVE_DELAY_MS 20 > + > #define MIPI_CTRL00_CLOCK_LANE_GATE BIT(5) > #define MIPI_CTRL00_BUS_IDLE BIT(2) > #define MIPI_CTRL00_CLOCK_LANE_DISABLE BIT(0) > @@ -86,6 +94,7 @@ struct ov5647 { > unsigned int height; > int power_count; > struct clk *xclk; > + struct gpio_desc *pwdn; > }; > > static inline struct ov5647 *to_state(struct v4l2_subdev *sd) > @@ -93,6 +102,11 @@ static inline struct ov5647 *to_state(struct v4l2_subdev *sd) > return container_of(sd, struct ov5647, sd); > } > > +static inline void msleep_range(unsigned int delay_base) > +{ > + usleep_range(delay_base * 1000, delay_base * 1000 + 5000); > +} > + I think I mis-lead you with the comment I gave on v1, as I just notice the designated timeout is 20 msec, so msleep() is fine. Sorry about this, I thought we were dealing with a shorter interval. If that's ok with you I'll send a v3 of this series with Sakari's comments addressed, rebased on top of the yaml version of the sensor bindings I sent out a few hours ago. Thanks j > static struct regval_list sensor_oe_disable_regs[] = { > {0x3000, 0x00}, > {0x3001, 0x00}, > @@ -355,6 +369,11 @@ static int ov5647_sensor_power(struct v4l2_subdev *sd, int on) > if (on && !ov5647->power_count) { > dev_dbg(&client->dev, "OV5647 power on\n"); > > + if (ov5647->pwdn) { > + gpiod_set_value(ov5647->pwdn, 0); > + msleep_range(PWDN_ACTIVE_DELAY_MS); > + } > + > ret = clk_prepare_enable(ov5647->xclk); > if (ret < 0) { > dev_err(&client->dev, "clk prepare enable failed\n"); > @@ -392,6 +411,8 @@ static int ov5647_sensor_power(struct v4l2_subdev *sd, int on) > dev_dbg(&client->dev, "soft stby failed\n"); > > clk_disable_unprepare(ov5647->xclk); > + > + gpiod_set_value(ov5647->pwdn, 1); > } > > /* Update the power count. */ > @@ -603,6 +624,10 @@ static int ov5647_probe(struct i2c_client *client) > return -EINVAL; > } > > + /* Request the power down GPIO asserted */ > + sensor->pwdn = devm_gpiod_get_optional(&client->dev, "pwdn", > + GPIOD_OUT_HIGH); > + > mutex_init(&sensor->lock); > > sd = &sensor->sd; > @@ -616,7 +641,15 @@ static int ov5647_probe(struct i2c_client *client) > if (ret < 0) > goto mutex_remove; > > + if (sensor->pwdn) { > + gpiod_set_value(sensor->pwdn, 0); > + msleep_range(PWDN_ACTIVE_DELAY_MS); > + } > + > ret = ov5647_detect(sd); > + > + gpiod_set_value(sensor->pwdn, 1); > + > if (ret < 0) > goto error; > > -- > 2.17.1 >