Linux-ARM-MSM Archive on lore.kernel.org
 help / color / Atom feed
From: Bhaumik Bhatt <bbhatt@codeaurora.org>
To: manivannan.sadhasivam@linaro.org
Cc: linux-arm-msm@vger.kernel.org, hemantk@codeaurora.org,
	jhugo@codeaurora.org, linux-kernel@vger.kernel.org,
	Bhaumik Bhatt <bbhatt@codeaurora.org>
Subject: [PATCH v6 11/11] bus: mhi: core: Introduce sysfs entries for MHI
Date: Mon, 27 Jul 2020 19:02:20 -0700
Message-ID: <1595901740-27379-12-git-send-email-bbhatt@codeaurora.org> (raw)
In-Reply-To: <1595901740-27379-1-git-send-email-bbhatt@codeaurora.org>

Introduce sysfs entries to enable userspace clients the ability to read
the serial number and the OEM PK Hash values obtained from BHI. OEMs
need to read these device-specific hardware information values through
userspace for factory testing purposes and cannot be exposed via degbufs
as it may remain disabled for performance reasons. Also, update the
documentation for ABI to include these entries.

Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
---
 Documentation/ABI/stable/sysfs-bus-mhi | 21 ++++++++++++++
 MAINTAINERS                            |  1 +
 drivers/bus/mhi/core/init.c            | 53 ++++++++++++++++++++++++++++++++++
 3 files changed, 75 insertions(+)
 create mode 100644 Documentation/ABI/stable/sysfs-bus-mhi

diff --git a/Documentation/ABI/stable/sysfs-bus-mhi b/Documentation/ABI/stable/sysfs-bus-mhi
new file mode 100644
index 0000000..1d5d0d6
--- /dev/null
+++ b/Documentation/ABI/stable/sysfs-bus-mhi
@@ -0,0 +1,21 @@
+What:		/sys/bus/mhi/devices/.../serialnumber
+Date:		Jul 2020
+KernelVersion:	5.8
+Contact:	Bhaumik Bhatt <bbhatt@codeaurora.org>
+Description:	The file holds the serial number of the client device obtained
+		using a BHI (Boot Host Interface) register read after at least
+		one attempt to power up the device has been done. If read
+		without having the device power on at least once, the file will
+		read all 0's.
+Users:		Any userspace application or clients interested in device info.
+
+What:		/sys/bus/mhi/devices/.../oem_pk_hash
+Date:		Jul 2020
+KernelVersion:	5.8
+Contact:	Bhaumik Bhatt <bbhatt@codeaurora.org>
+Description:	The file holds the OEM PK Hash value of the endpoint device
+		obtained using a BHI (Boot Host Interface) register read after
+		at least one attempt to power up the device has been done. If
+		read without having the device power on at least once, the file
+		will read all 0's.
+Users:		Any userspace application or clients interested in device info.
diff --git a/MAINTAINERS b/MAINTAINERS
index e64e5db..5e49316 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11018,6 +11018,7 @@ M:	Hemant Kumar <hemantk@codeaurora.org>
 L:	linux-arm-msm@vger.kernel.org
 S:	Maintained
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mani/mhi.git
+F:	Documentation/ABI/stable/sysfs-bus-mhi
 F:	Documentation/mhi/
 F:	drivers/bus/mhi/
 F:	include/linux/mhi.h
diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 972dbf0..c086ef2 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -76,6 +76,56 @@ const char *to_mhi_pm_state_str(enum mhi_pm_state state)
 	return mhi_pm_state_str[index];
 }
 
+static ssize_t serial_number_show(struct device *dev,
+				  struct device_attribute *attr,
+				  char *buf)
+{
+	struct mhi_device *mhi_dev = to_mhi_device(dev);
+	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
+
+	return snprintf(buf, PAGE_SIZE, "Serial Number: %u\n",
+			mhi_cntrl->serial_number);
+}
+static DEVICE_ATTR_RO(serial_number);
+
+static ssize_t oem_pk_hash_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	struct mhi_device *mhi_dev = to_mhi_device(dev);
+	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
+	int i, cnt = 0;
+
+	for (i = 0; i < ARRAY_SIZE(mhi_cntrl->oem_pk_hash); i++)
+		cnt += snprintf(buf + cnt, PAGE_SIZE - cnt,
+				"OEMPKHASH[%d]: 0x%x\n", i,
+				mhi_cntrl->oem_pk_hash[i]);
+
+	return cnt;
+}
+static DEVICE_ATTR_RO(oem_pk_hash);
+
+static struct attribute *mhi_sysfs_attrs[] = {
+	&dev_attr_serial_number.attr,
+	&dev_attr_oem_pk_hash.attr,
+	NULL,
+};
+
+static const struct attribute_group mhi_sysfs_group = {
+	.attrs = mhi_sysfs_attrs,
+};
+
+static int mhi_create_sysfs(struct mhi_controller *mhi_cntrl)
+{
+	return sysfs_create_group(&mhi_cntrl->mhi_dev->dev.kobj,
+				  &mhi_sysfs_group);
+}
+
+static void mhi_destroy_sysfs(struct mhi_controller *mhi_cntrl)
+{
+	sysfs_remove_group(&mhi_cntrl->mhi_dev->dev.kobj, &mhi_sysfs_group);
+}
+
 /* MHI protocol requires the transfer ring to be aligned with ring length */
 static int mhi_alloc_aligned_ring(struct mhi_controller *mhi_cntrl,
 				  struct mhi_ring *ring,
@@ -917,6 +967,8 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
 	mhi_cntrl->mhi_dev = mhi_dev;
 
 	mhi_create_debugfs(mhi_cntrl);
+	if (mhi_create_sysfs(mhi_cntrl))
+		dev_err(mhi_cntrl->cntrl_dev, "Failed to create sysfs entries\n");
 
 	return 0;
 
@@ -940,6 +992,7 @@ void mhi_unregister_controller(struct mhi_controller *mhi_cntrl)
 	struct mhi_chan *mhi_chan = mhi_cntrl->mhi_chan;
 	unsigned int i;
 
+	mhi_destroy_sysfs(mhi_cntrl);
 	mhi_destroy_debugfs(mhi_cntrl);
 
 	kfree(mhi_cntrl->mhi_cmd);
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project


  parent reply index

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-28  2:02 [PATCH v6 00/11] Introduce features and debugfs/sysfs " Bhaumik Bhatt
2020-07-28  2:02 ` [PATCH v6 01/11] bus: mhi: core: Remove double occurrence for mhi_ctrl_ev_task() declaration Bhaumik Bhatt
2020-07-28  2:02 ` [PATCH v6 02/11] bus: mhi: core: Abort suspends due to outgoing pending packets Bhaumik Bhatt
2020-07-28  2:02 ` [PATCH v6 03/11] bus: mhi: core: Use helper API to trigger a non-blocking host resume Bhaumik Bhatt
2020-07-28  2:02 ` [PATCH v6 04/11] bus: mhi: core: Trigger host resume if suspended during mhi_device_get() Bhaumik Bhatt
2020-07-28  2:02 ` [PATCH v6 05/11] bus: mhi: core: Use generic name field for an MHI device Bhaumik Bhatt
2020-07-28  2:02 ` [PATCH v6 06/11] bus: mhi: core: Introduce helper function to check device state Bhaumik Bhatt
2020-07-28  2:02 ` [PATCH v6 07/11] bus: mhi: core: Introduce counters to track MHI device state transitions Bhaumik Bhatt
2020-08-07  5:13   ` Manivannan Sadhasivam
2020-07-28  2:02 ` [PATCH v6 08/11] bus: mhi: core: Introduce debugfs entries for MHI Bhaumik Bhatt
2020-08-01  7:08   ` kernel test robot
2020-07-28  2:02 ` [PATCH v6 09/11] bus: mhi: core: Read and save device hardware information from BHI Bhaumik Bhatt
2020-07-28  2:02 ` [PATCH v6 10/11] bus: mhi: core: Introduce APIs to allocate and free the MHI controller Bhaumik Bhatt
2020-08-07  5:15   ` Manivannan Sadhasivam
2020-07-28  2:02 ` Bhaumik Bhatt [this message]
2020-08-07  5:22   ` [PATCH v6 11/11] bus: mhi: core: Introduce sysfs entries for MHI Manivannan Sadhasivam
2020-08-10 19:11     ` bbhatt

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=1595901740-27379-12-git-send-email-bbhatt@codeaurora.org \
    --to=bbhatt@codeaurora.org \
    --cc=hemantk@codeaurora.org \
    --cc=jhugo@codeaurora.org \
    --cc=linux-arm-msm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=manivannan.sadhasivam@linaro.org \
    /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-ARM-MSM Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-arm-msm/0 linux-arm-msm/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-arm-msm linux-arm-msm/ https://lore.kernel.org/linux-arm-msm \
		linux-arm-msm@vger.kernel.org
	public-inbox-index linux-arm-msm

Example config snippet for mirrors

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


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