From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sivakumar Thulasimani Subject: Re: [PATCH v3] drm/i915: Add debugfs to read/write any DPCD register Date: Mon, 20 Apr 2015 18:33:43 +0530 Message-ID: <5534F92F.10200@intel.com> References: <1429529894-8771-1-git-send-email-durgadoss.r@intel.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1042942280==" Return-path: Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTP id 8FDD56E150 for ; Mon, 20 Apr 2015 06:04:03 -0700 (PDT) In-Reply-To: <1429529894-8771-1-git-send-email-durgadoss.r@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Durgadoss R Cc: intel-gfx@lists.freedesktop.org, ville.syrjala@intel.com, paulo.r.zanoni@intel.com List-Id: intel-gfx@lists.freedesktop.org This is a multi-part message in MIME format. --===============1042942280== Content-Type: multipart/alternative; boundary="------------030308060406090004060406" This is a multi-part message in MIME format. --------------030308060406090004060406 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Reviewed-by: Sivakumar Thulasimani On 4/20/2015 5:08 PM, Durgadoss R wrote: > This patch creates a connector specific debugfs > interface to read any particular DPCD register. > The DPCD register address (hex format) is written > to 'i915_dpcd_addr' interface and the corresponding > value can be read from 'i915_dpcd_val' interface. > > To write into a DPCD register, echo a value into > 'i915_dpcd_val' interface. This will return -EIO > for invalid writes. > > Example usage: > echo 0x2 > i915_dpcd_addr > cat i915_dpcd_val > 0x84 > > To write 0x1 to DPCD 0x170: > echo 0x170 > i915_dpcd_addr > echo 0x1 > i915_dpcd_val > cat i915_dpcd_val > 0x1 > > v2: Address Jani's comments. > > v3: Added capability to write DPCD also (Ville) > > Signed-off-by: Durgadoss R > --- > drivers/gpu/drm/i915/i915_debugfs.c | 120 +++++++++++++++++++++++++++++++++++- > drivers/gpu/drm/i915/intel_drv.h | 1 + > 2 files changed, 120 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c > index 9c2b9e4..79c876e 100644 > --- a/drivers/gpu/drm/i915/i915_debugfs.c > +++ b/drivers/gpu/drm/i915/i915_debugfs.c > @@ -4968,6 +4968,119 @@ static const struct file_operations i915_dpcd_fops = { > .release = single_release, > }; > > +static ssize_t i915_dpcd_addr_write(struct file *file, const char __user *ubuf, > + size_t len, loff_t *offp) > +{ > + struct seq_file *m = file->private_data; > + struct drm_connector *connector = m->private; > + struct intel_dp *intel_dp = > + enc_to_intel_dp(&intel_attached_encoder(connector)->base); > + unsigned int reg_addr; > + char tmp[16]; > + > + if (len >= sizeof(tmp)) > + return -EINVAL; > + > + if (copy_from_user(tmp, ubuf, len)) > + return -EFAULT; > + > + tmp[len] = '\0'; > + > + if (kstrtouint(tmp, 16, ®_addr)) > + return -EINVAL; > + > + intel_dp->debugfs_dpcd_addr = reg_addr; > + > + return len; > +} > + > +static int i915_dpcd_addr_show(struct seq_file *m, void *data) > +{ > + struct drm_connector *connector = m->private; > + struct intel_dp *intel_dp = > + enc_to_intel_dp(&intel_attached_encoder(connector)->base); > + > + seq_printf(m, "0x%x\n", intel_dp->debugfs_dpcd_addr); > + > + return 0; > +} > + > +static int i915_dpcd_addr_open(struct inode *inode, struct file *file) > +{ > + return single_open(file, i915_dpcd_addr_show, inode->i_private); > +} > + > +static const struct file_operations i915_dpcd_addr_fops = { > + .owner = THIS_MODULE, > + .open = i915_dpcd_addr_open, > + .read = seq_read, > + .write = i915_dpcd_addr_write, > + .llseek = seq_lseek, > + .release = single_release, > +}; > + > +static ssize_t i915_dpcd_val_write(struct file *file, const char __user *ubuf, > + size_t len, loff_t *offp) > +{ > + struct seq_file *m = file->private_data; > + struct drm_connector *connector = m->private; > + struct intel_dp *intel_dp = > + enc_to_intel_dp(&intel_attached_encoder(connector)->base); > + unsigned int addr = intel_dp->debugfs_dpcd_addr; > + unsigned int val; > + char tmp[16]; > + int ret; > + > + if (len >= sizeof(tmp)) > + return -EINVAL; > + > + if (copy_from_user(tmp, ubuf, len)) > + return -EFAULT; > + > + tmp[len] = '\0'; > + > + if (kstrtouint(tmp, 16, &val)) > + return -EINVAL; > + > + ret = drm_dp_dpcd_writeb(&intel_dp->aux, addr, val); > + if (ret < 0) > + return ret; > + > + return len; > +} > + > +static int i915_dpcd_val_show(struct seq_file *m, void *data) > +{ > + struct drm_connector *connector = m->private; > + struct intel_dp *intel_dp = > + enc_to_intel_dp(&intel_attached_encoder(connector)->base); > + unsigned int addr; > + u8 val; > + int ret; > + > + addr = intel_dp->debugfs_dpcd_addr; > + ret = drm_dp_dpcd_readb(&intel_dp->aux, addr, &val); > + if (ret < 0) > + return ret; > + > + seq_printf(m, "0x%x\n", val); > + return 0; > +} > + > +static int i915_dpcd_val_open(struct inode *inode, struct file *file) > +{ > + return single_open(file, i915_dpcd_val_show, inode->i_private); > +} > + > +static const struct file_operations i915_dpcd_val_fops = { > + .owner = THIS_MODULE, > + .open = i915_dpcd_val_open, > + .read = seq_read, > + .write = i915_dpcd_val_write, > + .llseek = seq_lseek, > + .release = single_release, > +}; > + > /** > * i915_debugfs_connector_add - add i915 specific connector debugfs files > * @connector: pointer to a registered drm_connector > @@ -4986,9 +5099,14 @@ int i915_debugfs_connector_add(struct drm_connector *connector) > return -ENODEV; > > if (connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort || > - connector->connector_type == DRM_MODE_CONNECTOR_eDP) > + connector->connector_type == DRM_MODE_CONNECTOR_eDP) { > debugfs_create_file("i915_dpcd", S_IRUGO, root, connector, > &i915_dpcd_fops); > + debugfs_create_file("i915_dpcd_addr", S_IRUGO | S_IWUSR, > + root, connector, &i915_dpcd_addr_fops); > + debugfs_create_file("i915_dpcd_val", S_IRUGO | S_IWUSR, > + root, connector, &i915_dpcd_val_fops); > + } > > return 0; > } > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h > index 23a42a4..4477d14 100644 > --- a/drivers/gpu/drm/i915/intel_drv.h > +++ b/drivers/gpu/drm/i915/intel_drv.h > @@ -709,6 +709,7 @@ struct intel_dp { > unsigned long last_power_cycle; > unsigned long last_power_on; > unsigned long last_backlight_off; > + unsigned int debugfs_dpcd_addr; > > struct notifier_block edp_notifier; > --------------030308060406090004060406 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 7bit

Reviewed-by: Sivakumar Thulasimani <sivakumar.thulasimani@intel.com>


On 4/20/2015 5:08 PM, Durgadoss R wrote:
This patch creates a connector specific debugfs
interface to read any particular DPCD register.
The DPCD register address (hex format) is written
to 'i915_dpcd_addr' interface and the corresponding
value can be read from 'i915_dpcd_val' interface.

To write into a DPCD register, echo a value into
'i915_dpcd_val' interface. This will return -EIO
for invalid writes.

Example usage:
echo 0x2 > i915_dpcd_addr
cat i915_dpcd_val
0x84

To write 0x1 to DPCD 0x170:
echo 0x170 > i915_dpcd_addr
echo 0x1 > i915_dpcd_val
cat i915_dpcd_val
0x1

v2: Address Jani's comments.

v3: Added capability to write DPCD also (Ville)

Signed-off-by: Durgadoss R <durgadoss.r@intel.com>
---
 drivers/gpu/drm/i915/i915_debugfs.c | 120 +++++++++++++++++++++++++++++++++++-
 drivers/gpu/drm/i915/intel_drv.h    |   1 +
 2 files changed, 120 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 9c2b9e4..79c876e 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -4968,6 +4968,119 @@ static const struct file_operations i915_dpcd_fops = {
 	.release = single_release,
 };
 
+static ssize_t i915_dpcd_addr_write(struct file *file, const char __user *ubuf,
+				     size_t len, loff_t *offp)
+{
+	struct seq_file *m = file->private_data;
+	struct drm_connector *connector = m->private;
+	struct intel_dp *intel_dp =
+		enc_to_intel_dp(&intel_attached_encoder(connector)->base);
+	unsigned int reg_addr;
+	char tmp[16];
+
+	if (len >= sizeof(tmp))
+		return -EINVAL;
+
+	if (copy_from_user(tmp, ubuf, len))
+		return -EFAULT;
+
+	tmp[len] = '\0';
+
+	if (kstrtouint(tmp, 16, &reg_addr))
+		return -EINVAL;
+
+	intel_dp->debugfs_dpcd_addr = reg_addr;
+
+	return len;
+}
+
+static int i915_dpcd_addr_show(struct seq_file *m, void *data)
+{
+	struct drm_connector *connector = m->private;
+	struct intel_dp *intel_dp =
+		enc_to_intel_dp(&intel_attached_encoder(connector)->base);
+
+	seq_printf(m, "0x%x\n", intel_dp->debugfs_dpcd_addr);
+
+	return 0;
+}
+
+static int i915_dpcd_addr_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, i915_dpcd_addr_show, inode->i_private);
+}
+
+static const struct file_operations i915_dpcd_addr_fops = {
+	.owner = THIS_MODULE,
+	.open = i915_dpcd_addr_open,
+	.read = seq_read,
+	.write = i915_dpcd_addr_write,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+static ssize_t i915_dpcd_val_write(struct file *file, const char __user *ubuf,
+				     size_t len, loff_t *offp)
+{
+	struct seq_file *m = file->private_data;
+	struct drm_connector *connector = m->private;
+	struct intel_dp *intel_dp =
+		enc_to_intel_dp(&intel_attached_encoder(connector)->base);
+	unsigned int addr = intel_dp->debugfs_dpcd_addr;
+	unsigned int val;
+	char tmp[16];
+	int ret;
+
+	if (len >= sizeof(tmp))
+		return -EINVAL;
+
+	if (copy_from_user(tmp, ubuf, len))
+		return -EFAULT;
+
+	tmp[len] = '\0';
+
+	if (kstrtouint(tmp, 16, &val))
+		return -EINVAL;
+
+	ret = drm_dp_dpcd_writeb(&intel_dp->aux, addr, val);
+	if (ret < 0)
+		return ret;
+
+	return len;
+}
+
+static int i915_dpcd_val_show(struct seq_file *m, void *data)
+{
+	struct drm_connector *connector = m->private;
+	struct intel_dp *intel_dp =
+		enc_to_intel_dp(&intel_attached_encoder(connector)->base);
+	unsigned int addr;
+	u8 val;
+	int ret;
+
+	addr = intel_dp->debugfs_dpcd_addr;
+	ret = drm_dp_dpcd_readb(&intel_dp->aux, addr, &val);
+	if (ret < 0)
+		return ret;
+
+	seq_printf(m, "0x%x\n", val);
+	return 0;
+}
+
+static int i915_dpcd_val_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, i915_dpcd_val_show, inode->i_private);
+}
+
+static const struct file_operations i915_dpcd_val_fops = {
+	.owner = THIS_MODULE,
+	.open = i915_dpcd_val_open,
+	.read = seq_read,
+	.write = i915_dpcd_val_write,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
 /**
  * i915_debugfs_connector_add - add i915 specific connector debugfs files
  * @connector: pointer to a registered drm_connector
@@ -4986,9 +5099,14 @@ int i915_debugfs_connector_add(struct drm_connector *connector)
 		return -ENODEV;
 
 	if (connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort ||
-	    connector->connector_type == DRM_MODE_CONNECTOR_eDP)
+	    connector->connector_type == DRM_MODE_CONNECTOR_eDP) {
 		debugfs_create_file("i915_dpcd", S_IRUGO, root, connector,
 				    &i915_dpcd_fops);
+		debugfs_create_file("i915_dpcd_addr", S_IRUGO | S_IWUSR,
+				root, connector, &i915_dpcd_addr_fops);
+		debugfs_create_file("i915_dpcd_val", S_IRUGO | S_IWUSR,
+				root, connector, &i915_dpcd_val_fops);
+	}
 
 	return 0;
 }
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 23a42a4..4477d14 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -709,6 +709,7 @@ struct intel_dp {
 	unsigned long last_power_cycle;
 	unsigned long last_power_on;
 	unsigned long last_backlight_off;
+	unsigned int debugfs_dpcd_addr;
 
 	struct notifier_block edp_notifier;

--------------030308060406090004060406-- --===============1042942280== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KSW50ZWwtZ2Z4 IG1haWxpbmcgbGlzdApJbnRlbC1nZnhAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHA6Ly9saXN0 cy5mcmVlZGVza3RvcC5vcmcvbWFpbG1hbi9saXN0aW5mby9pbnRlbC1nZngK --===============1042942280==--