Linux-i2c Archive on lore.kernel.org
 help / color / Atom feed
From: Sowjanya Komatineni <skomatineni@nvidia.com>
To: <skomatineni@nvidia.com>, <thierry.reding@gmail.com>,
	<jonathanh@nvidia.com>, <frankc@nvidia.com>, <hverkuil@xs4all.nl>,
	<sakari.ailus@iki.fi>, <robh+dt@kernel.org>,
	<helen.koike@collabora.com>
Cc: <digetx@gmail.com>, <sboyd@kernel.org>,
	<gregkh@linuxfoundation.org>, <linux-media@vger.kernel.org>,
	<devicetree@vger.kernel.org>, <linux-tegra@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>, <linux-i2c@vger.kernel.org>
Subject: [RFC PATCH v6 08/10] gpu: host1x: mipi: Keep MIPI clock enabled till calibration is done
Date: Fri, 31 Jul 2020 02:02:47 -0700
Message-ID: <1596186169-18729-9-git-send-email-skomatineni@nvidia.com> (raw)
In-Reply-To: <1596186169-18729-1-git-send-email-skomatineni@nvidia.com>

With the split of MIPI calibration into tegra_mipi_calibrate() and
tegra_mipi_wait(), MIPI clock is not kept enabled till the calibration
is done.

So, this patch skips disabling MIPI clock after triggering start of
calibration and disables it only after waiting for done status from
the calibration logic.

This patch renames tegra_mipi_calibrate() as tegra_mipi_start_calibration()
and tegra_mipi_wait() as tegra_mipi_finish_calibration() to be inline
with their usage.

As MIPI clock is left enabled and in case of any failures with CSI input
streaming tegra_mipi_finish_calibration() will not get invoked.
So added new API tegra_mipi_cancel_calibration() which disables MIPI clock
and consumer drivers can call this in such cases.

Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
---
 drivers/gpu/drm/tegra/dsi.c |  4 ++--
 drivers/gpu/host1x/mipi.c   | 19 ++++++++++---------
 include/linux/host1x.h      |  5 +++--
 3 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/tegra/dsi.c b/drivers/gpu/drm/tegra/dsi.c
index 3820e8d..a7864e9 100644
--- a/drivers/gpu/drm/tegra/dsi.c
+++ b/drivers/gpu/drm/tegra/dsi.c
@@ -694,11 +694,11 @@ static int tegra_dsi_pad_calibrate(struct tegra_dsi *dsi)
 		DSI_PAD_PREEMP_PD(0x03) | DSI_PAD_PREEMP_PU(0x3);
 	tegra_dsi_writel(dsi, value, DSI_PAD_CONTROL_3);
 
-	err = tegra_mipi_calibrate(dsi->mipi);
+	err = tegra_mipi_start_calibration(dsi->mipi);
 	if (err < 0)
 		return err;
 
-	return tegra_mipi_wait(dsi->mipi);
+	return tegra_mipi_finish_calibration(dsi->mipi);
 }
 
 static void tegra_dsi_set_timeout(struct tegra_dsi *dsi, unsigned long bclk,
diff --git a/drivers/gpu/host1x/mipi.c b/drivers/gpu/host1x/mipi.c
index e606464..b15ab6e 100644
--- a/drivers/gpu/host1x/mipi.c
+++ b/drivers/gpu/host1x/mipi.c
@@ -293,17 +293,19 @@ int tegra_mipi_disable(struct tegra_mipi_device *dev)
 }
 EXPORT_SYMBOL(tegra_mipi_disable);
 
-int tegra_mipi_wait(struct tegra_mipi_device *device)
+void tegra_mipi_cancel_calibration(struct tegra_mipi_device *device)
+{
+	clk_disable(device->mipi->clk);
+}
+EXPORT_SYMBOL(tegra_mipi_cancel_calibration);
+
+int tegra_mipi_finish_calibration(struct tegra_mipi_device *device)
 {
 	struct tegra_mipi *mipi = device->mipi;
 	void __iomem *status_reg = mipi->regs + (MIPI_CAL_STATUS << 2);
 	u32 value;
 	int err;
 
-	err = clk_enable(device->mipi->clk);
-	if (err < 0)
-		return err;
-
 	mutex_lock(&device->mipi->lock);
 
 	err = readl_relaxed_poll_timeout(status_reg, value,
@@ -315,9 +317,9 @@ int tegra_mipi_wait(struct tegra_mipi_device *device)
 
 	return err;
 }
-EXPORT_SYMBOL(tegra_mipi_wait);
+EXPORT_SYMBOL(tegra_mipi_finish_calibration);
 
-int tegra_mipi_calibrate(struct tegra_mipi_device *device)
+int tegra_mipi_start_calibration(struct tegra_mipi_device *device)
 {
 	const struct tegra_mipi_soc *soc = device->mipi->soc;
 	unsigned int i;
@@ -382,11 +384,10 @@ int tegra_mipi_calibrate(struct tegra_mipi_device *device)
 	tegra_mipi_writel(device->mipi, value, MIPI_CAL_CTRL);
 
 	mutex_unlock(&device->mipi->lock);
-	clk_disable(device->mipi->clk);
 
 	return 0;
 }
-EXPORT_SYMBOL(tegra_mipi_calibrate);
+EXPORT_SYMBOL(tegra_mipi_start_calibration);
 
 static const struct tegra_mipi_pad tegra114_mipi_pads[] = {
 	{ .data = MIPI_CAL_CONFIG_CSIA },
diff --git a/include/linux/host1x.h b/include/linux/host1x.h
index 20c885d..b490dda 100644
--- a/include/linux/host1x.h
+++ b/include/linux/host1x.h
@@ -333,7 +333,8 @@ struct tegra_mipi_device *tegra_mipi_request(struct device *device,
 void tegra_mipi_free(struct tegra_mipi_device *device);
 int tegra_mipi_enable(struct tegra_mipi_device *device);
 int tegra_mipi_disable(struct tegra_mipi_device *device);
-int tegra_mipi_calibrate(struct tegra_mipi_device *device);
-int tegra_mipi_wait(struct tegra_mipi_device *device);
+int tegra_mipi_start_calibration(struct tegra_mipi_device *device);
+int tegra_mipi_finish_calibration(struct tegra_mipi_device *device);
+void tegra_mipi_cancel_calibration(struct tegra_mipi_device *device);
 
 #endif
-- 
2.7.4


  parent reply index

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-31  9:02 [RFC PATCH v6 00/10] Support for Tegra video capture from external sensor Sowjanya Komatineni
2020-07-31  9:02 ` [RFC PATCH v6 01/10] media: tegra-video: Fix channel format alignment Sowjanya Komatineni
2020-07-31  9:02 ` [RFC PATCH v6 02/10] media: tegra-video: Enable TPG based on kernel config Sowjanya Komatineni
2020-07-31  9:02 ` [RFC PATCH v6 03/10] media: tegra-video: Update format lookup to offset based Sowjanya Komatineni
2020-07-31  9:02 ` [RFC PATCH v6 04/10] dt-bindings: tegra: Update VI and CSI bindings with port info Sowjanya Komatineni
2020-07-31  9:02 ` [RFC PATCH v6 05/10] media: tegra-video: Separate CSI stream enable and disable implementations Sowjanya Komatineni
2020-07-31 12:06   ` Dmitry Osipenko
2020-07-31  9:02 ` [RFC PATCH v6 06/10] media: tegra-video: Add support for external sensor capture Sowjanya Komatineni
2020-07-31  9:02 ` [RFC PATCH v6 07/10] media: tegra-video: Add support for selection ioctl ops Sowjanya Komatineni
2020-07-31  9:02 ` Sowjanya Komatineni [this message]
2020-07-31  9:02 ` [RFC PATCH v6 09/10] media: tegra-video: Add CSI MIPI pads calibration Sowjanya Komatineni
2020-07-31 11:39   ` Dmitry Osipenko
2020-07-31 15:46     ` Sowjanya Komatineni
2020-07-31 16:14       ` Dmitry Osipenko
2020-07-31 16:29         ` Sowjanya Komatineni
2020-07-31  9:02 ` [RFC PATCH v6 10/10] media: tegra-video: Compute settle times based on the clock rate Sowjanya Komatineni
2020-07-31 13:40 ` [RFC PATCH v6 00/10] Support for Tegra video capture from external sensor Wolfram Sang
2020-07-31 15:49   ` Sowjanya Komatineni

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1596186169-18729-9-git-send-email-skomatineni@nvidia.com \
    --to=skomatineni@nvidia.com \
    --cc=devicetree@vger.kernel.org \
    --cc=digetx@gmail.com \
    --cc=frankc@nvidia.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=helen.koike@collabora.com \
    --cc=hverkuil@xs4all.nl \
    --cc=jonathanh@nvidia.com \
    --cc=linux-i2c@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-media@vger.kernel.org \
    --cc=linux-tegra@vger.kernel.org \
    --cc=robh+dt@kernel.org \
    --cc=sakari.ailus@iki.fi \
    --cc=sboyd@kernel.org \
    --cc=thierry.reding@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-i2c Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-i2c/0 linux-i2c/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-i2c linux-i2c/ https://lore.kernel.org/linux-i2c \
		linux-i2c@vger.kernel.org
	public-inbox-index linux-i2c

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-i2c


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git