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From: Lubomir Rintel <lkundrak@v3.sk>
To: Mauro Carvalho Chehab <mchehab@kernel.org>,
	Jonathan Corbet <corbet@lwn.net>,
	linux-media@vger.kernel.org
Cc: Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	Lubomir Rintel <lkundrak@v3.sk>, James Cameron <quozl@laptop.org>,
	Pavel Machek <pavel@ucw.cz>, Libin Yang <lbyang@marvell.com>,
	Albert Wang <twang13@marvell.com>
Subject: [PATCH v3 04/14] media: ov7670: control clock along with power
Date: Tue, 20 Nov 2018 11:03:09 +0100	[thread overview]
Message-ID: <20181120100318.367987-5-lkundrak@v3.sk> (raw)
In-Reply-To: <20181120100318.367987-1-lkundrak@v3.sk>

This provides more power saving when the sensor is off.

While at that, do the delay on power/clock enable even if the sensor driver
itself doesn't control the GPIOs. This is required for the OLPC XO-1
platform, that lacks the proper power/reset properties in its DT, but
needs the delay after the sensor is clocked up.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
---
 drivers/media/i2c/ov7670.c | 30 ++++++++++++++----------------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/drivers/media/i2c/ov7670.c b/drivers/media/i2c/ov7670.c
index cbaab60aaaac..d7635fb2d713 100644
--- a/drivers/media/i2c/ov7670.c
+++ b/drivers/media/i2c/ov7670.c
@@ -1623,14 +1623,17 @@ static void ov7670_power_on(struct v4l2_subdev *sd)
 	if (info->on)
 		return;
 
+	clk_prepare_enable(info->clk);
+
 	if (info->pwdn_gpio)
 		gpiod_set_value(info->pwdn_gpio, 0);
 	if (info->resetb_gpio) {
 		gpiod_set_value(info->resetb_gpio, 1);
 		usleep_range(500, 1000);
 		gpiod_set_value(info->resetb_gpio, 0);
-		usleep_range(3000, 5000);
 	}
+	if (info->pwdn_gpio || info->resetb_gpio || info->clk)
+		usleep_range(3000, 5000);
 
 	info->on = true;
 }
@@ -1642,6 +1645,8 @@ static void ov7670_power_off(struct v4l2_subdev *sd)
 	if (!info->on)
 		return;
 
+	clk_disable_unprepare(info->clk);
+
 	if (info->pwdn_gpio)
 		gpiod_set_value(info->pwdn_gpio, 1);
 
@@ -1863,24 +1868,20 @@ static int ov7670_probe(struct i2c_client *client,
 			return ret;
 	}
 
-	if (info->clk) {
-		ret = clk_prepare_enable(info->clk);
-		if (ret)
-			return ret;
+	ret = ov7670_init_gpio(client, info);
+	if (ret)
+		return ret;
 
+	ov7670_power_on(sd);
+
+	if (info->clk) {
 		info->clock_speed = clk_get_rate(info->clk) / 1000000;
 		if (info->clock_speed < 10 || info->clock_speed > 48) {
 			ret = -EINVAL;
-			goto clk_disable;
+			goto power_off;
 		}
 	}
 
-	ret = ov7670_init_gpio(client, info);
-	if (ret)
-		goto clk_disable;
-
-	ov7670_power_on(sd);
-
 	/* Make sure it's an ov7670 */
 	ret = ov7670_detect(sd);
 	if (ret) {
@@ -1960,6 +1961,7 @@ static int ov7670_probe(struct i2c_client *client,
 	if (ret < 0)
 		goto entity_cleanup;
 
+	ov7670_power_off(sd);
 	return 0;
 
 entity_cleanup:
@@ -1968,12 +1970,9 @@ static int ov7670_probe(struct i2c_client *client,
 	v4l2_ctrl_handler_free(&info->hdl);
 power_off:
 	ov7670_power_off(sd);
-clk_disable:
-	clk_disable_unprepare(info->clk);
 	return ret;
 }
 
-
 static int ov7670_remove(struct i2c_client *client)
 {
 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
@@ -1981,7 +1980,6 @@ static int ov7670_remove(struct i2c_client *client)
 
 	v4l2_async_unregister_subdev(sd);
 	v4l2_ctrl_handler_free(&info->hdl);
-	clk_disable_unprepare(info->clk);
 	media_entity_cleanup(&info->sd.entity);
 	ov7670_power_off(sd);
 	return 0;
-- 
2.19.1


  parent reply	other threads:[~2018-11-20 10:04 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-20 10:03 [PATCH v3 0/14] media: make Marvell camera work on DT-based OLPC XO-1.75 Lubomir Rintel
2018-11-20 10:03 ` [PATCH v3 01/14] media: ov7670: split register setting from set_fmt() logic Lubomir Rintel
2018-11-22 18:37   ` jacopo mondi
2018-11-28 17:10     ` Lubomir Rintel
2018-11-20 10:03 ` [PATCH v3 02/14] media: ov7670: split register setting from set_framerate() logic Lubomir Rintel
2019-01-14 23:03   ` Sakari Ailus
2019-01-15  8:30     ` Lubomir Rintel
2019-01-15  8:45       ` Sakari Ailus
2018-11-20 10:03 ` [PATCH v3 03/14] media: ov7670: hook s_power onto v4l2 core Lubomir Rintel
2018-11-22 12:21   ` Sakari Ailus
2018-11-28 11:29     ` Lubomir Rintel
2019-01-10 16:59       ` Sakari Ailus
2019-01-13 16:38         ` Lubomir Rintel
2018-11-20 10:03 ` Lubomir Rintel [this message]
2018-11-20 10:03 ` [PATCH v3 05/14] media: dt-bindings: marvell,mmp2-ccic: Add Marvell MMP2 camera Lubomir Rintel
2018-11-22 20:08   ` jacopo mondi
2019-04-25 14:28     ` Lubomir Rintel
2018-11-27 10:08   ` Sakari Ailus
2018-11-20 10:03 ` [PATCH v3 06/14] [media] marvell-ccic: fix DMA s/g desc number calculation Lubomir Rintel
2018-11-20 10:03 ` [PATCH v3 07/14] [media] marvell-ccic: don't generate EOF on parallel bus Lubomir Rintel
2018-11-20 10:03 ` [PATCH v3 08/14] Revert "[media] marvell-ccic: reset ccic phy when stop streaming for stability" Lubomir Rintel
2018-11-20 10:03 ` [PATCH v3 09/14] [media] marvell-ccic: drop unused stuff Lubomir Rintel
2018-11-20 10:03 ` [PATCH v3 10/14] [media] marvell-ccic/mmp: enable clock before accessing registers Lubomir Rintel
2018-11-20 10:03 ` [PATCH v3 11/14] [media] marvell-ccic: rename the clocks Lubomir Rintel
2018-11-20 10:03 ` [PATCH v3 12/14] [media] marvell-ccic/mmp: add devicetree support Lubomir Rintel
2018-11-20 10:03 ` [PATCH v3 13/14] [media] marvell-ccic: use async notifier to get the sensor Lubomir Rintel
2018-11-20 10:03 ` [PATCH v3 14/14] [media] marvell-ccic: provide a clock for " Lubomir Rintel
2018-11-23  7:44   ` jacopo mondi
2019-04-25 13:33     ` Lubomir Rintel

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