[PATCH v2 0/6] Introduce features and debugfs/sysfs entries for MHI

[PATCH v2 0/6] Introduce features and debugfs/sysfs entries for MHI

[Bhaumik Bhatt]

Introduce independent bus and device voting mechanism for clients and save
hardware information from BHI.
Allow reading and modifying some MHI variables for debug, test, and
information purposes using debugfs.
Read values for device specific hardware information to be used by OEMs in
factory testing such as serial number and PK hash using sysfs.

This set of patches was tested on arm64 and x86.

v2:
-Please note: an upcoming ath11k driver patch will depend on the following patch:
"bus: mhi: core: Introduce independent voting mechanism"
-Fixed typo in one of the patches
-Updated MAINTAINERS for the sysfs ABI documentation

Bhaumik Bhatt (6):
  bus: mhi: core: Introduce independent voting mechanism
  bus: mhi: core: Use generic name field for an MHI device
  bus: mhi: core: Introduce helper function to check device state
  bus: mhi: core: Introduce debugfs entries and counters for MHI
  bus: mhi: core: Read and save device hardware information from BHI
  bus: mhi: core: Introduce sysfs entries for MHI

 Documentation/ABI/stable/sysfs-bus-mhi |  25 ++
 MAINTAINERS                            |   1 +
 drivers/bus/mhi/Kconfig                |   8 +
 drivers/bus/mhi/core/Makefile          |   5 +-
 drivers/bus/mhi/core/boot.c            |  17 +-
 drivers/bus/mhi/core/debugfs.c         | 431 +++++++++++++++++++++++++++++++++
 drivers/bus/mhi/core/init.c            |  80 +++++-
 drivers/bus/mhi/core/internal.h        |  29 +++
 drivers/bus/mhi/core/main.c            |   6 +-
 drivers/bus/mhi/core/pm.c              |  79 ++++--
 include/linux/mhi.h                    |  39 ++-
 11 files changed, 673 insertions(+), 47 deletions(-)
 create mode 100644 Documentation/ABI/stable/sysfs-bus-mhi
 create mode 100644 drivers/bus/mhi/core/debugfs.c

-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH v2 1/6] bus: mhi: core: Introduce independent voting mechanism

[Bhaumik Bhatt]

Allow independent votes from clients such that they can choose to vote
for either the device or the bus or both. This helps in cases where the
device supports autonomous low power mode wherein it can move to M2
state without the need to notify the host. Clients can also vote only to
keep the underlying bus active without having the device in M0 state to
support offload use cases.

Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
---
 drivers/bus/mhi/core/init.c | 15 +++++----
 drivers/bus/mhi/core/pm.c   | 75 ++++++++++++++++++++++++++++++++-------------
 include/linux/mhi.h         | 21 ++++++++-----
 3 files changed, 77 insertions(+), 34 deletions(-)

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 12207cc..d5bebe5 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -1061,7 +1061,8 @@ struct mhi_device *mhi_alloc_device(struct mhi_controller *mhi_cntrl)
 	dev->release = mhi_release_device;
 	dev->parent = mhi_cntrl->cntrl_dev;
 	mhi_dev->mhi_cntrl = mhi_cntrl;
-	mhi_dev->dev_wake = 0;
+	atomic_set(&mhi_dev->dev_vote, 0);
+	atomic_set(&mhi_dev->bus_vote, 0);
 
 	return mhi_dev;
 }
@@ -1078,7 +1079,7 @@ static int mhi_driver_probe(struct device *dev)
 	int ret;
 
 	/* Bring device out of LPM */
-	ret = mhi_device_get_sync(mhi_dev);
+	ret = mhi_device_get_sync(mhi_dev, MHI_VOTE_DEVICE);
 	if (ret)
 		return ret;
 
@@ -1137,14 +1138,14 @@ static int mhi_driver_probe(struct device *dev)
 	if (dl_chan && dl_chan->auto_start)
 		mhi_prepare_channel(mhi_cntrl, dl_chan);
 
-	mhi_device_put(mhi_dev);
+	mhi_device_put(mhi_dev, MHI_VOTE_DEVICE);
 
 	return ret;
 
 exit_probe:
 	mhi_unprepare_from_transfer(mhi_dev);
 
-	mhi_device_put(mhi_dev);
+	mhi_device_put(mhi_dev, MHI_VOTE_DEVICE);
 
 	return ret;
 }
@@ -1213,8 +1214,10 @@ static int mhi_driver_remove(struct device *dev)
 	}
 
 	read_lock_bh(&mhi_cntrl->pm_lock);
-	while (mhi_dev->dev_wake)
-		mhi_device_put(mhi_dev);
+	while (atomic_read(&mhi_dev->dev_vote))
+		mhi_device_put(mhi_dev, MHI_VOTE_DEVICE);
+	while (atomic_read(&mhi_dev->bus_vote))
+		mhi_device_put(mhi_dev, MHI_VOTE_BUS);
 	read_unlock_bh(&mhi_cntrl->pm_lock);
 
 	return 0;
diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index de5abb2..0b68dcd 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -675,7 +675,8 @@ void mhi_pm_st_worker(struct work_struct *work)
 int mhi_pm_suspend(struct mhi_controller *mhi_cntrl)
 {
 	struct mhi_chan *itr, *tmp;
-	struct device *dev = &mhi_cntrl->mhi_dev->dev;
+	struct mhi_device *mhi_dev = mhi_cntrl->mhi_dev;
+	struct device *dev = &mhi_dev->dev;
 	enum mhi_pm_state new_state;
 	int ret;
 
@@ -686,7 +687,8 @@ int mhi_pm_suspend(struct mhi_controller *mhi_cntrl)
 		return -EIO;
 
 	/* Return busy if there are any pending resources */
-	if (atomic_read(&mhi_cntrl->dev_wake))
+	if (atomic_read(&mhi_cntrl->dev_wake) ||
+	    atomic_read(&mhi_dev->bus_vote))
 		return -EBUSY;
 
 	/* Take MHI out of M2 state */
@@ -712,10 +714,9 @@ int mhi_pm_suspend(struct mhi_controller *mhi_cntrl)
 
 	write_lock_irq(&mhi_cntrl->pm_lock);
 
-	if (atomic_read(&mhi_cntrl->dev_wake)) {
-		write_unlock_irq(&mhi_cntrl->pm_lock);
+	if (atomic_read(&mhi_cntrl->dev_wake) ||
+	    atomic_read(&mhi_dev->bus_vote))
 		return -EBUSY;
-	}
 
 	dev_info(dev, "Allowing M3 transition\n");
 	new_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_M3_ENTER);
@@ -1080,42 +1081,74 @@ int mhi_force_rddm_mode(struct mhi_controller *mhi_cntrl)
 }
 EXPORT_SYMBOL_GPL(mhi_force_rddm_mode);
 
-void mhi_device_get(struct mhi_device *mhi_dev)
+void mhi_device_get(struct mhi_device *mhi_dev, int vote)
 {
 	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
 
-	mhi_dev->dev_wake++;
-	read_lock_bh(&mhi_cntrl->pm_lock);
-	mhi_cntrl->wake_get(mhi_cntrl, true);
-	read_unlock_bh(&mhi_cntrl->pm_lock);
+	if (vote & MHI_VOTE_DEVICE) {
+		atomic_inc(&mhi_dev->dev_vote);
+		read_lock_bh(&mhi_cntrl->pm_lock);
+		mhi_cntrl->wake_get(mhi_cntrl, true);
+		read_unlock_bh(&mhi_cntrl->pm_lock);
+	}
+
+	if (vote & MHI_VOTE_BUS) {
+		atomic_inc(&mhi_dev->bus_vote);
+		mhi_cntrl->runtime_get(mhi_cntrl);
+	}
 }
 EXPORT_SYMBOL_GPL(mhi_device_get);
 
-int mhi_device_get_sync(struct mhi_device *mhi_dev)
+int mhi_device_get_sync(struct mhi_device *mhi_dev, int vote)
 {
 	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
 	int ret;
 
+	/* bring device out of low power modes regardless of the type of vote */
 	ret = __mhi_device_get_sync(mhi_cntrl);
-	if (!ret)
-		mhi_dev->dev_wake++;
+	if (ret)
+		return ret;
+
+	if (vote & MHI_VOTE_DEVICE) {
+		atomic_inc(&mhi_dev->dev_vote);
+	} else {
+		/* remove device vote as it was not requested */
+		read_lock_bh(&mhi_cntrl->pm_lock);
+		mhi_cntrl->wake_put(mhi_cntrl, false);
+		read_unlock_bh(&mhi_cntrl->pm_lock);
+	}
+
+	if (vote & MHI_VOTE_BUS) {
+		atomic_inc(&mhi_dev->bus_vote);
+		mhi_cntrl->runtime_get(mhi_cntrl);
+	}
 
 	return ret;
 }
 EXPORT_SYMBOL_GPL(mhi_device_get_sync);
 
-void mhi_device_put(struct mhi_device *mhi_dev)
+void mhi_device_put(struct mhi_device *mhi_dev, int vote)
 {
 	struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
 
-	mhi_dev->dev_wake--;
-	read_lock_bh(&mhi_cntrl->pm_lock);
-	if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state)) {
-		mhi_cntrl->runtime_get(mhi_cntrl);
-		mhi_cntrl->runtime_put(mhi_cntrl);
+	if (vote & MHI_VOTE_DEVICE) {
+		atomic_dec(&mhi_dev->dev_vote);
+		read_lock_bh(&mhi_cntrl->pm_lock);
+		if (MHI_PM_IN_SUSPEND_STATE(mhi_cntrl->pm_state)) {
+			mhi_cntrl->runtime_get(mhi_cntrl);
+			mhi_cntrl->runtime_put(mhi_cntrl);
+		}
+		mhi_cntrl->wake_put(mhi_cntrl, false);
+		read_unlock_bh(&mhi_cntrl->pm_lock);
 	}
 
-	mhi_cntrl->wake_put(mhi_cntrl, false);
-	read_unlock_bh(&mhi_cntrl->pm_lock);
+	if (vote & MHI_VOTE_BUS) {
+		atomic_dec(&mhi_dev->bus_vote);
+		mhi_cntrl->runtime_put(mhi_cntrl);
+
+		/* notify controller that all bus votes are removed */
+		if (!atomic_read(&mhi_dev->bus_vote))
+			mhi_cntrl->status_cb(mhi_cntrl, MHI_CB_IDLE);
+	}
 }
 EXPORT_SYMBOL_GPL(mhi_device_put);
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index b008914..10fcb52 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -16,6 +16,9 @@
 #include <linux/wait.h>
 #include <linux/workqueue.h>
 
+#define MHI_VOTE_BUS BIT(0) /* do not disable the mhi bus */
+#define MHI_VOTE_DEVICE BIT(1) /* prevent mhi device from entering lpm */
+
 struct mhi_chan;
 struct mhi_event;
 struct mhi_ctxt;
@@ -459,7 +462,8 @@ struct mhi_device {
 	enum mhi_device_type dev_type;
 	int ul_chan_id;
 	int dl_chan_id;
-	u32 dev_wake;
+	atomic_t dev_vote;
+	atomic_t bus_vote;
 };
 
 /**
@@ -644,23 +648,26 @@ void mhi_set_mhi_state(struct mhi_controller *mhi_cntrl,
 enum mhi_state mhi_get_mhi_state(struct mhi_controller *mhi_cntrl);
 
 /**
- * mhi_device_get - Disable device low power mode
+ * mhi_device_get - Disable device and/or bus low power mode
  * @mhi_dev: Device associated with the channel
+ * @vote: requested vote (bus, device or both)
  */
-void mhi_device_get(struct mhi_device *mhi_dev);
+void mhi_device_get(struct mhi_device *mhi_dev, int vote);
 
 /**
- * mhi_device_get_sync - Disable device low power mode. Synchronously
+ * mhi_device_get_sync - Disable device and/or bus low power mode. Synchronously
  *                       take the controller out of suspended state
  * @mhi_dev: Device associated with the channel
+ * @vote: requested vote (bus, device or both)
  */
-int mhi_device_get_sync(struct mhi_device *mhi_dev);
+int mhi_device_get_sync(struct mhi_device *mhi_dev, int vote);
 
 /**
- * mhi_device_put - Re-enable device low power mode
+ * mhi_device_put - Re-enable device and/or bus low power mode
  * @mhi_dev: Device associated with the channel
+ * @vote: vote(s) to remove (bus, device or both)
  */
-void mhi_device_put(struct mhi_device *mhi_dev);
+void mhi_device_put(struct mhi_device *mhi_dev, int vote);
 
 /**
  * mhi_prepare_for_transfer - Setup channel for data transfer
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH v2 2/6] bus: mhi: core: Use generic name field for an MHI device

[Bhaumik Bhatt]

An MHI device is not necessarily associated with only channels as we can
have one associated with the controller itself. Hence, the chan_name
field within the mhi_device structure should instead be replaced with a
generic name to accurately reflect any type of MHI device.

Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org>
---
 drivers/bus/mhi/core/init.c | 5 +++--
 drivers/bus/mhi/core/main.c | 6 +++---
 include/linux/mhi.h         | 8 ++++----
 3 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index d5bebe5..da94a04 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -903,6 +903,7 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
 	mhi_dev->dev_type = MHI_DEVICE_CONTROLLER;
 	mhi_dev->mhi_cntrl = mhi_cntrl;
 	dev_set_name(&mhi_dev->dev, "%s", dev_name(mhi_cntrl->cntrl_dev));
+	mhi_dev->name = dev_name(mhi_cntrl->cntrl_dev);
 
 	/* Init wakeup source */
 	device_init_wakeup(&mhi_dev->dev, true);
@@ -1250,7 +1251,7 @@ static int mhi_uevent(struct device *dev, struct kobj_uevent_env *env)
 	struct mhi_device *mhi_dev = to_mhi_device(dev);
 
 	return add_uevent_var(env, "MODALIAS=" MHI_DEVICE_MODALIAS_FMT,
-					mhi_dev->chan_name);
+					mhi_dev->name);
 }
 
 static int mhi_match(struct device *dev, struct device_driver *drv)
@@ -1267,7 +1268,7 @@ static int mhi_match(struct device *dev, struct device_driver *drv)
 		return 0;
 
 	for (id = mhi_drv->id_table; id->chan[0]; id++)
-		if (!strcmp(mhi_dev->chan_name, id->chan)) {
+		if (!strcmp(mhi_dev->name, id->chan)) {
 			mhi_dev->id = id;
 			return 1;
 		}
diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
index 1f622ce..bafc12a 100644
--- a/drivers/bus/mhi/core/main.c
+++ b/drivers/bus/mhi/core/main.c
@@ -249,7 +249,7 @@ int mhi_destroy_device(struct device *dev, void *data)
 		put_device(&mhi_dev->dl_chan->mhi_dev->dev);
 
 	dev_dbg(&mhi_cntrl->mhi_dev->dev, "destroy device for chan:%s\n",
-		 mhi_dev->chan_name);
+		 mhi_dev->name);
 
 	/* Notify the client and remove the device from MHI bus */
 	device_del(dev);
@@ -327,10 +327,10 @@ void mhi_create_devices(struct mhi_controller *mhi_cntrl)
 		}
 
 		/* Channel name is same for both UL and DL */
-		mhi_dev->chan_name = mhi_chan->name;
+		mhi_dev->name = mhi_chan->name;
 		dev_set_name(&mhi_dev->dev, "%s_%s",
 			     dev_name(mhi_cntrl->cntrl_dev),
-			     mhi_dev->chan_name);
+			     mhi_dev->name);
 
 		/* Init wakeup source if available */
 		if (mhi_dev->dl_chan && mhi_dev->dl_chan->wake_capable)
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index 10fcb52..9b7bf28 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -439,10 +439,10 @@ struct mhi_controller {
 };
 
 /**
- * struct mhi_device - Structure representing a MHI device which binds
- *                     to channels
+ * struct mhi_device - Structure representing an MHI device which binds
+ *                     to channels or is associated with controllers
  * @id: Pointer to MHI device ID struct
- * @chan_name: Name of the channel to which the device binds
+ * @name: Name of the associated MHI device
  * @mhi_cntrl: Controller the device belongs to
  * @ul_chan: UL channel for the device
  * @dl_chan: DL channel for the device
@@ -454,7 +454,7 @@ struct mhi_controller {
  */
 struct mhi_device {
 	const struct mhi_device_id *id;
-	const char *chan_name;
+	const char *name;
 	struct mhi_controller *mhi_cntrl;
 	struct mhi_chan *ul_chan;
 	struct mhi_chan *dl_chan;
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH v2 3/6] bus: mhi: core: Introduce helper function to check device state

[Bhaumik Bhatt]

Introduce a helper function to determine whether the device is in a
powered ON state and resides in one of the active MHI states. This will
allow for some use cases in reading debugfs entries.

Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org>
---
 drivers/bus/mhi/core/internal.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h
index b1f640b..2f18be7 100644
--- a/drivers/bus/mhi/core/internal.h
+++ b/drivers/bus/mhi/core/internal.h
@@ -599,6 +599,11 @@ int mhi_queue_state_transition(struct mhi_controller *mhi_cntrl,
 int __mhi_device_get_sync(struct mhi_controller *mhi_cntrl);
 int mhi_send_cmd(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan,
 		 enum mhi_cmd_type cmd);
+static inline bool mhi_is_active(struct mhi_controller *mhi_cntrl)
+{
+	return (mhi_cntrl->dev_state >= MHI_STATE_M0 &&
+		mhi_cntrl->dev_state <= MHI_STATE_M3_FAST);
+}
 
 /* Register access methods */
 void mhi_db_brstmode(struct mhi_controller *mhi_cntrl, struct db_cfg *db_cfg,
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH v2 4/6] bus: mhi: core: Introduce debugfs entries and counters for MHI

[Bhaumik Bhatt]

Introduce debugfs entries to show state, channel, and event ring
information. Add MHI state counters to keep track of the state changes
on the device and add a helper API mhi_to_physical() to see the physical
address from debugfs. Also, allow the host to trigger a device reset,
issue bus or device votes, and change the MHI timeout to help in debug.

Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
---
 drivers/bus/mhi/Kconfig         |   8 +
 drivers/bus/mhi/core/Makefile   |   5 +-
 drivers/bus/mhi/core/debugfs.c  | 431 ++++++++++++++++++++++++++++++++++++++++
 drivers/bus/mhi/core/init.c     |   7 +
 drivers/bus/mhi/core/internal.h |  24 +++
 drivers/bus/mhi/core/pm.c       |   4 +
 include/linux/mhi.h             |   4 +
 7 files changed, 480 insertions(+), 3 deletions(-)
 create mode 100644 drivers/bus/mhi/core/debugfs.c

diff --git a/drivers/bus/mhi/Kconfig b/drivers/bus/mhi/Kconfig
index a8bd9bd..6a217ff 100644
--- a/drivers/bus/mhi/Kconfig
+++ b/drivers/bus/mhi/Kconfig
@@ -12,3 +12,11 @@ config MHI_BUS
 	 communication protocol used by the host processors to control
 	 and communicate with modem devices over a high speed peripheral
 	 bus or shared memory.
+
+config MHI_BUS_DEBUG
+	bool "Debugfs support for the MHI bus"
+	depends on MHI_BUS && DEBUG_FS
+	help
+	 Enable debugfs support for use with the MHI transport. Allows
+	 reading and/or modifying some values within the MHI controller
+	 for debug and test purposes.
diff --git a/drivers/bus/mhi/core/Makefile b/drivers/bus/mhi/core/Makefile
index 66e2700..460a548 100644
--- a/drivers/bus/mhi/core/Makefile
+++ b/drivers/bus/mhi/core/Makefile
@@ -1,3 +1,2 @@
-obj-$(CONFIG_MHI_BUS) := mhi.o
-
-mhi-y := init.o main.o pm.o boot.o
+obj-$(CONFIG_MHI_BUS) := init.o main.o pm.o boot.o
+obj-$(CONFIG_MHI_BUS_DEBUG) += debugfs.o
diff --git a/drivers/bus/mhi/core/debugfs.c b/drivers/bus/mhi/core/debugfs.c
new file mode 100644
index 0000000..fa70666
--- /dev/null
+++ b/drivers/bus/mhi/core/debugfs.c
@@ -0,0 +1,431 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020, The Linux Foundation. All rights reserved.
+ *
+ */
+
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/mhi.h>
+#include "internal.h"
+
+static int mhi_debugfs_states_show(struct seq_file *m, void *d)
+{
+	struct mhi_controller *mhi_cntrl = m->private;
+
+	/* states */
+	seq_printf(m, "PM state:%s Device:%s MHI state:%s EE:%s wake:%s\n",
+		   to_mhi_pm_state_str(mhi_cntrl->pm_state),
+		   mhi_is_active(mhi_cntrl) ? "Active" : "Inactive",
+		   TO_MHI_STATE_STR(mhi_cntrl->dev_state),
+		   TO_MHI_EXEC_STR(mhi_cntrl->ee),
+		   mhi_cntrl->wake_set ? "true" : "false");
+
+	/* counters */
+	seq_printf(m, "M0:%u M2:%u M3:%u M3_Fast:%u", mhi_cntrl->M0,
+		   mhi_cntrl->M2, mhi_cntrl->M3, mhi_cntrl->M3_fast);
+
+	seq_printf(m, " device wake:%u pending packets:%u\n",
+		   atomic_read(&mhi_cntrl->dev_wake),
+		   atomic_read(&mhi_cntrl->pending_pkts));
+
+	return 0;
+}
+
+static int mhi_debugfs_events_show(struct seq_file *m, void *d)
+{
+	struct mhi_controller *mhi_cntrl = m->private;
+	struct mhi_event *mhi_event;
+	struct mhi_event_ctxt *er_ctxt;
+	int i;
+
+	if (!mhi_is_active(mhi_cntrl)) {
+		seq_puts(m, "Device not ready\n");
+		return -ENODEV;
+	}
+
+	er_ctxt = mhi_cntrl->mhi_ctxt->er_ctxt;
+	mhi_event = mhi_cntrl->mhi_event;
+	for (i = 0; i < mhi_cntrl->total_ev_rings;
+						i++, er_ctxt++, mhi_event++) {
+		struct mhi_ring *ring = &mhi_event->ring;
+
+		if (mhi_event->offload_ev) {
+			seq_printf(m, "Index:%d is an offload event ring\n", i);
+			continue;
+		}
+
+		seq_printf(m, "Index:%d intmod count:%lu time:%lu",
+			   i, (er_ctxt->intmod & EV_CTX_INTMODC_MASK) >>
+			   EV_CTX_INTMODC_SHIFT,
+			   (er_ctxt->intmod & EV_CTX_INTMODT_MASK) >>
+			   EV_CTX_INTMODT_SHIFT);
+
+		seq_printf(m, " base:0x%0llx len:0x%llx", er_ctxt->rbase,
+			   er_ctxt->rlen);
+
+		seq_printf(m,
+			   " rp:0x%llx wp:0x%llx local rp:0x%llx db:0x%llx\n",
+			   er_ctxt->rp, er_ctxt->wp, (u64)ring->rp,
+			   mhi_event->db_cfg.db_val);
+	}
+
+	return 0;
+}
+
+static int mhi_debugfs_channels_show(struct seq_file *m, void *d)
+{
+	struct mhi_controller *mhi_cntrl = m->private;
+	struct mhi_chan *mhi_chan;
+	struct mhi_chan_ctxt *chan_ctxt;
+	int i;
+
+	if (!mhi_is_active(mhi_cntrl)) {
+		seq_puts(m, "Device not ready\n");
+		return -ENODEV;
+	}
+
+	mhi_chan = mhi_cntrl->mhi_chan;
+	chan_ctxt = mhi_cntrl->mhi_ctxt->chan_ctxt;
+	for (i = 0; i < mhi_cntrl->max_chan; i++, chan_ctxt++, mhi_chan++) {
+		struct mhi_ring *ring = &mhi_chan->tre_ring;
+
+		if (mhi_chan->offload_ch) {
+			seq_printf(m, "%s(%u) is an offload channel\n",
+				   mhi_chan->name, mhi_chan->chan);
+			continue;
+		}
+
+		if (!mhi_chan->mhi_dev)
+			continue;
+
+		seq_printf(m,
+			   "%s(%u) state:0x%lx brstmode:0x%lx pollcfg:0x%lx",
+			   mhi_chan->name, mhi_chan->chan, (chan_ctxt->chcfg &
+			   CHAN_CTX_CHSTATE_MASK) >> CHAN_CTX_CHSTATE_SHIFT,
+			   (chan_ctxt->chcfg & CHAN_CTX_BRSTMODE_MASK) >>
+			   CHAN_CTX_BRSTMODE_SHIFT, (chan_ctxt->chcfg &
+			   CHAN_CTX_POLLCFG_MASK) >> CHAN_CTX_POLLCFG_SHIFT);
+
+		seq_printf(m, " type:0x%x event ring:%u", chan_ctxt->chtype,
+			   chan_ctxt->erindex);
+
+		seq_printf(m, " base:0x%llx len:0x%llx wp:0x%llx",
+			   chan_ctxt->rbase, chan_ctxt->rlen, chan_ctxt->wp);
+
+		seq_printf(m, " local rp:0x%llx local wp:0x%llx db:0x%llx\n",
+			   (u64)ring->rp, (u64)ring->wp,
+			   mhi_chan->db_cfg.db_val);
+	}
+
+	return 0;
+}
+
+static int mhi_device_votes_show(struct device *dev, void *data)
+{
+	struct mhi_device *mhi_dev;
+
+	if (dev->bus != &mhi_bus_type)
+		return 0;
+
+	mhi_dev = to_mhi_device(dev);
+
+	seq_printf((struct seq_file *)data, "%s: device:%u, bus:%u\n",
+		   mhi_dev->name, atomic_read(&mhi_dev->dev_vote),
+		   atomic_read(&mhi_dev->bus_vote));
+
+	return 0;
+}
+
+static int mhi_debugfs_votes_show(struct seq_file *m, void *d)
+{
+	struct mhi_controller *mhi_cntrl = m->private;
+
+	if (!mhi_is_active(mhi_cntrl)) {
+		seq_puts(m, "Device not ready\n");
+		return -ENODEV;
+	}
+
+	device_for_each_child(mhi_cntrl->cntrl_dev, m, mhi_device_votes_show);
+
+	return 0;
+}
+
+static int mhi_debugfs_bus_vote_show(struct seq_file *m, void *d)
+{
+	struct mhi_controller *mhi_cntrl = m->private;
+	struct mhi_device *mhi_dev = mhi_cntrl->mhi_dev;
+
+	if (!mhi_is_active(mhi_cntrl)) {
+		seq_puts(m, "Device not ready\n");
+		return -ENODEV;
+	}
+
+	seq_printf(m, "Votes: %d\n%s\n", atomic_read(&mhi_dev->bus_vote),
+		   "Usage: echo get/put > bus_vote for vote/unvote");
+
+	return 0;
+}
+
+static ssize_t mhi_debugfs_bus_vote_write(struct file *file,
+					  const char __user *ubuf,
+					  size_t count, loff_t *ppos)
+{
+	struct seq_file	*m = file->private_data;
+	struct mhi_controller *mhi_cntrl = m->private;
+	struct mhi_device *mhi_dev = mhi_cntrl->mhi_dev;
+	char buf[32];
+	int ret = -EINVAL;
+
+	if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
+		return -EFAULT;
+
+	if (!strncmp(buf, "get", 3)) {
+		ret = mhi_device_get_sync(mhi_dev, MHI_VOTE_BUS);
+	} else if (!strncmp(buf, "put", 3)) {
+		mhi_device_put(mhi_dev, MHI_VOTE_BUS);
+		ret = 0;
+	}
+
+	return ret ? ret : count;
+}
+
+static int mhi_debugfs_device_vote_show(struct seq_file *m, void *d)
+{
+	struct mhi_controller *mhi_cntrl = m->private;
+	struct mhi_device *mhi_dev = mhi_cntrl->mhi_dev;
+
+	if (!mhi_is_active(mhi_cntrl)) {
+		seq_puts(m, "Device not ready\n");
+		return -ENODEV;
+	}
+
+	seq_printf(m,
+		   "Votes: %d\n%s\n", atomic_read(&mhi_dev->dev_vote),
+		   "Usage: echo get/put > device_vote for vote/unvote");
+
+	return 0;
+}
+
+static ssize_t mhi_debugfs_device_vote_write(struct file *file,
+					     const char __user *ubuf,
+					     size_t count, loff_t *ppos)
+{
+	struct seq_file	*m = file->private_data;
+	struct mhi_controller *mhi_cntrl = m->private;
+	struct mhi_device *mhi_dev = mhi_cntrl->mhi_dev;
+	char buf[32];
+	int ret = -EINVAL;
+
+	if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
+		return -EFAULT;
+
+	if (!strncmp(buf, "get", 3)) {
+		ret = mhi_device_get_sync(mhi_dev, MHI_VOTE_DEVICE);
+	} else if (!strncmp(buf, "put", 3)) {
+		mhi_device_put(mhi_dev, MHI_VOTE_DEVICE);
+		ret = 0;
+	}
+
+	return ret ? ret : count;
+}
+
+static int mhi_debugfs_timeout_ms_show(struct seq_file *m, void *d)
+{
+	struct mhi_controller *mhi_cntrl = m->private;
+
+	seq_printf(m, "%u ms\n", mhi_cntrl->timeout_ms);
+
+	return 0;
+}
+
+static ssize_t mhi_debugfs_timeout_ms_write(struct file *file,
+					    const char __user *ubuf,
+					    size_t count, loff_t *ppos)
+{
+	struct seq_file	*m = file->private_data;
+	struct mhi_controller *mhi_cntrl = m->private;
+	u32 timeout_ms;
+
+	if (kstrtou32_from_user(ubuf, count, 0, &timeout_ms))
+		return -EINVAL;
+
+	mhi_cntrl->timeout_ms = timeout_ms;
+
+	return count;
+}
+
+static int mhi_debugfs_trigger_reset(void *data, u64 val)
+{
+	struct mhi_controller *mhi_cntrl = data;
+	struct mhi_device *mhi_dev = mhi_cntrl->mhi_dev;
+	struct device *dev = &mhi_dev->dev;
+	enum mhi_pm_state cur_state;
+	int ret = -EIO;
+
+	if (!mhi_is_active(mhi_cntrl))
+		return -ENODEV;
+
+	if (!val)
+		return -EINVAL;
+
+	ret = mhi_device_get_sync(mhi_dev, MHI_VOTE_DEVICE);
+	if (ret) {
+		dev_err(dev, "Device did not enter M0 state, MHI:%s, PM:%s\n",
+			TO_MHI_STATE_STR(mhi_cntrl->dev_state),
+			to_mhi_pm_state_str(mhi_cntrl->pm_state));
+		return ret;
+	}
+
+	if (mhi_cntrl->rddm_image) {
+		ret = mhi_force_rddm_mode(mhi_cntrl);
+		goto exit_mhi_trigger_reset;
+	}
+
+	write_lock_irq(&mhi_cntrl->pm_lock);
+	cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_SYS_ERR_DETECT);
+	write_unlock_irq(&mhi_cntrl->pm_lock);
+
+	if (cur_state != MHI_PM_SYS_ERR_DETECT)
+		goto exit_mhi_trigger_reset;
+
+	mhi_pm_sys_err_handler(mhi_cntrl);
+	ret = 0;
+
+exit_mhi_trigger_reset:
+	mhi_device_put(mhi_dev, MHI_VOTE_DEVICE);
+
+	return ret;
+}
+
+static int mhi_debugfs_states_open(struct inode *inode, struct file *fp)
+{
+	return single_open(fp, mhi_debugfs_states_show, inode->i_private);
+}
+
+static int mhi_debugfs_events_open(struct inode *inode, struct file *fp)
+{
+	return single_open(fp, mhi_debugfs_events_show, inode->i_private);
+}
+
+static int mhi_debugfs_channels_open(struct inode *inode, struct file *fp)
+{
+	return single_open(fp, mhi_debugfs_channels_show, inode->i_private);
+}
+
+static int mhi_debugfs_votes_open(struct inode *inode, struct file *fp)
+{
+	return single_open(fp, mhi_debugfs_votes_show, inode->i_private);
+}
+
+static int mhi_debugfs_bus_vote_open(struct inode *inode, struct file *fp)
+{
+	return single_open(fp, mhi_debugfs_bus_vote_show, inode->i_private);
+}
+
+static int mhi_debugfs_device_vote_open(struct inode *inode, struct file *fp)
+{
+	return single_open(fp, mhi_debugfs_device_vote_show, inode->i_private);
+}
+
+static int mhi_debugfs_timeout_ms_open(struct inode *inode, struct file *fp)
+{
+	return single_open(fp, mhi_debugfs_timeout_ms_show, inode->i_private);
+}
+
+static const struct file_operations debugfs_states_fops = {
+	.open = mhi_debugfs_states_open,
+	.release = single_release,
+	.read = seq_read,
+};
+
+static const struct file_operations debugfs_events_fops = {
+	.open = mhi_debugfs_events_open,
+	.release = single_release,
+	.read = seq_read,
+};
+
+static const struct file_operations debugfs_channels_fops = {
+	.open = mhi_debugfs_channels_open,
+	.release = single_release,
+	.read = seq_read,
+};
+
+static const struct file_operations debugfs_votes_fops = {
+	.open = mhi_debugfs_votes_open,
+	.release = single_release,
+	.read = seq_read,
+};
+
+static const struct file_operations debugfs_bus_vote_fops = {
+	.open = mhi_debugfs_bus_vote_open,
+	.write = mhi_debugfs_bus_vote_write,
+	.release = single_release,
+	.read = seq_read,
+};
+
+static const struct file_operations debugfs_device_vote_fops = {
+	.open = mhi_debugfs_device_vote_open,
+	.write = mhi_debugfs_device_vote_write,
+	.release = single_release,
+	.read = seq_read,
+};
+
+static const struct file_operations debugfs_timeout_ms_fops = {
+	.open = mhi_debugfs_timeout_ms_open,
+	.write = mhi_debugfs_timeout_ms_write,
+	.release = single_release,
+	.read = seq_read,
+};
+
+DEFINE_DEBUGFS_ATTRIBUTE(debugfs_reset_fops, NULL,
+			 mhi_debugfs_trigger_reset, "%llu\n");
+
+static struct dentry *mhi_debugfs_root;
+
+void mhi_create_debugfs(struct mhi_controller *mhi_cntrl)
+{
+	if (IS_ERR_OR_NULL(mhi_debugfs_root))
+		return;
+
+	mhi_cntrl->debugfs_dentry =
+			debugfs_create_dir(dev_name(mhi_cntrl->cntrl_dev),
+					   mhi_debugfs_root);
+	if (IS_ERR_OR_NULL(mhi_cntrl->debugfs_dentry))
+		return;
+
+	debugfs_create_file("states", 0444, mhi_cntrl->debugfs_dentry,
+			    mhi_cntrl, &debugfs_states_fops);
+	debugfs_create_file("events", 0444, mhi_cntrl->debugfs_dentry,
+			    mhi_cntrl, &debugfs_events_fops);
+	debugfs_create_file("channels", 0444, mhi_cntrl->debugfs_dentry,
+			    mhi_cntrl, &debugfs_channels_fops);
+	debugfs_create_file("votes", 0444, mhi_cntrl->debugfs_dentry,
+			    mhi_cntrl, &debugfs_votes_fops);
+	debugfs_create_file("bus_vote", 0644, mhi_cntrl->debugfs_dentry,
+			    mhi_cntrl, &debugfs_bus_vote_fops);
+	debugfs_create_file("device_vote", 0644, mhi_cntrl->debugfs_dentry,
+			    mhi_cntrl, &debugfs_device_vote_fops);
+	debugfs_create_file("timeout_ms", 0644, mhi_cntrl->debugfs_dentry,
+			    mhi_cntrl, &debugfs_timeout_ms_fops);
+	debugfs_create_file("reset", 0444, mhi_cntrl->debugfs_dentry,
+			    mhi_cntrl, &debugfs_reset_fops);
+}
+
+void mhi_destroy_debugfs(struct mhi_controller *mhi_cntrl)
+{
+	debugfs_remove_recursive(mhi_cntrl->debugfs_dentry);
+	mhi_cntrl->debugfs_dentry = NULL;
+}
+
+void mhi_debugfs_init(void)
+{
+	mhi_debugfs_root = debugfs_create_dir(mhi_bus_type.name, NULL);
+}
+
+void mhi_debugfs_exit(void)
+{
+	debugfs_remove_recursive(mhi_debugfs_root);
+}
diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index da94a04..17e3f7d 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -4,6 +4,7 @@
  *
  */
 
+#include <linux/debugfs.h>
 #include <linux/device.h>
 #include <linux/dma-direction.h>
 #include <linux/dma-mapping.h>
@@ -914,6 +915,8 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
 
 	mhi_cntrl->mhi_dev = mhi_dev;
 
+	mhi_create_debugfs(mhi_cntrl);
+
 	return 0;
 
 error_add_dev:
@@ -936,6 +939,8 @@ void mhi_unregister_controller(struct mhi_controller *mhi_cntrl)
 	struct mhi_chan *mhi_chan = mhi_cntrl->mhi_chan;
 	unsigned int i;
 
+	mhi_destroy_debugfs(mhi_cntrl);
+
 	kfree(mhi_cntrl->mhi_cmd);
 	kfree(mhi_cntrl->mhi_event);
 
@@ -1285,11 +1290,13 @@ struct bus_type mhi_bus_type = {
 
 static int __init mhi_init(void)
 {
+	mhi_debugfs_init();
 	return bus_register(&mhi_bus_type);
 }
 
 static void __exit mhi_exit(void)
 {
+	mhi_debugfs_exit();
 	bus_unregister(&mhi_bus_type);
 }
 
diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h
index 2f18be7..798aa483 100644
--- a/drivers/bus/mhi/core/internal.h
+++ b/drivers/bus/mhi/core/internal.h
@@ -570,6 +570,30 @@ struct mhi_chan {
 /* Default MHI timeout */
 #define MHI_TIMEOUT_MS (1000)
 
+/* debugfs related functions */
+#ifdef CONFIG_MHI_BUS_DEBUG
+void mhi_create_debugfs(struct mhi_controller *mhi_cntrl);
+void mhi_destroy_debugfs(struct mhi_controller *mhi_cntrl);
+void mhi_debugfs_init(void);
+void mhi_debugfs_exit(void);
+#else
+static inline void mhi_create_debugfs(struct mhi_controller *mhi_cntrl)
+{
+}
+
+static inline void mhi_destroy_debugfs(struct mhi_controller *mhi_cntrl)
+{
+}
+
+static inline void mhi_debugfs_init(void)
+{
+}
+
+static inline void mhi_debugfs_exit(void)
+{
+}
+#endif
+
 struct mhi_device *mhi_alloc_device(struct mhi_controller *mhi_cntrl);
 
 int mhi_destroy_device(struct device *dev, void *data);
diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index 0b68dcd..29d6cd7 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -256,6 +256,7 @@ int mhi_pm_m0_transition(struct mhi_controller *mhi_cntrl)
 		dev_err(dev, "Unable to transition to M0 state\n");
 		return -EIO;
 	}
+	mhi_cntrl->M0++;
 
 	/* Wake up the device */
 	read_lock_bh(&mhi_cntrl->pm_lock);
@@ -326,6 +327,8 @@ void mhi_pm_m1_transition(struct mhi_controller *mhi_cntrl)
 		mhi_cntrl->dev_state = MHI_STATE_M2;
 
 		write_unlock_irq(&mhi_cntrl->pm_lock);
+
+		mhi_cntrl->M2++;
 		wake_up_all(&mhi_cntrl->state_event);
 
 		/* If there are any pending resources, exit M2 immediately */
@@ -362,6 +365,7 @@ int mhi_pm_m3_transition(struct mhi_controller *mhi_cntrl)
 		return -EIO;
 	}
 
+	mhi_cntrl->M3++;
 	wake_up_all(&mhi_cntrl->state_event);
 
 	return 0;
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index 9b7bf28..026a624 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -291,6 +291,7 @@ struct mhi_controller_config {
  * @cntrl_dev: Pointer to the struct device of physical bus acting as the MHI
  *            controller (required)
  * @mhi_dev: MHI device instance for the controller
+ * @debugfs_dentry: MHI controller debugfs directory
  * @regs: Base address of MHI MMIO register space (required)
  * @bhi: Points to base of MHI BHI register space
  * @bhie: Points to base of MHI BHIe register space
@@ -329,6 +330,7 @@ struct mhi_controller_config {
  * @dev_state: MHI device state
  * @dev_wake: Device wakeup count
  * @pending_pkts: Pending packets for the controller
+ * @M0, M2, M3, M3_fast: Counters to track number of device MHI state changes
  * @transition_list: List of MHI state transitions
  * @transition_lock: Lock for protecting MHI state transition list
  * @wlock: Lock for protecting device wakeup
@@ -367,6 +369,7 @@ struct mhi_controller_config {
 struct mhi_controller {
 	struct device *cntrl_dev;
 	struct mhi_device *mhi_dev;
+	struct dentry *debugfs_dentry;
 	void __iomem *regs;
 	void __iomem *bhi;
 	void __iomem *bhie;
@@ -408,6 +411,7 @@ struct mhi_controller {
 	enum mhi_state dev_state;
 	atomic_t dev_wake;
 	atomic_t pending_pkts;
+	u32 M0, M2, M3, M3_fast;
 	struct list_head transition_list;
 	spinlock_t transition_lock;
 	spinlock_t wlock;
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH v2 5/6] bus: mhi: core: Read and save device hardware information from BHI

[Bhaumik Bhatt]

Device hardware specific information such as serial number and the OEM
PK hash can be read using BHI and saved on host to identify the
endpoint.

Signed-off-by: Bhaumik Bhatt <bbhatt@codeaurora.org>
Reviewed-by: Jeffrey Hugo <jhugo@codeaurora.org>
---
 drivers/bus/mhi/core/boot.c | 17 ++++++++++++++++-
 include/linux/mhi.h         |  6 ++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/bus/mhi/core/boot.c b/drivers/bus/mhi/core/boot.c
index 0b38014..24422f5 100644
--- a/drivers/bus/mhi/core/boot.c
+++ b/drivers/bus/mhi/core/boot.c
@@ -392,13 +392,28 @@ void mhi_fw_load_handler(struct mhi_controller *mhi_cntrl)
 	void *buf;
 	dma_addr_t dma_addr;
 	size_t size;
-	int ret;
+	int i, ret;
 
 	if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
 		dev_err(dev, "Device MHI is not in valid state\n");
 		return;
 	}
 
+	/* save hardware info from BHI */
+	ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_SERIALNU,
+			   &mhi_cntrl->serial_number);
+	if (ret)
+		dev_err(dev, "Could not capture serial number via BHI\n");
+
+	for (i = 0; i < ARRAY_SIZE(mhi_cntrl->oem_pk_hash); i++) {
+		ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->bhi, BHI_OEMPKHASH(i),
+				   &mhi_cntrl->oem_pk_hash[i]);
+		if (ret) {
+			dev_err(dev, "Could not capture OEM PK HASH via BHI\n");
+			break;
+		}
+	}
+
 	/* If device is in pass through, do reset to ready state transition */
 	if (mhi_cntrl->ee == MHI_EE_PTHRU)
 		goto fw_load_ee_pthru;
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index 026a624..42e4d1e 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -19,6 +19,8 @@
 #define MHI_VOTE_BUS BIT(0) /* do not disable the mhi bus */
 #define MHI_VOTE_DEVICE BIT(1) /* prevent mhi device from entering lpm */
 
+#define MHI_MAX_OEM_PK_HASH_SEGMENTS 16
+
 struct mhi_chan;
 struct mhi_event;
 struct mhi_ctxt;
@@ -318,6 +320,8 @@ struct mhi_controller_config {
  * @device_number: MHI controller device number
  * @major_version: MHI controller major revision number
  * @minor_version: MHI controller minor revision number
+ * @serial_number: MHI controller serial number obtained from BHI
+ * @oem_pk_hash: MHI controller OEM PK Hash obtained from BHI
  * @mhi_event: MHI event ring configurations table
  * @mhi_cmd: MHI command ring configurations table
  * @mhi_ctxt: MHI device context, shared memory between host and device
@@ -397,6 +401,8 @@ struct mhi_controller {
 	u32 device_number;
 	u32 major_version;
 	u32 minor_version;
+	u32 serial_number;
+	u32 oem_pk_hash[MHI_MAX_OEM_PK_HASH_SEGMENTS];
 
 	struct mhi_event *mhi_event;
 	struct mhi_cmd *mhi_cmd;
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH v2 6/6] bus: mhi: core: Introduce sysfs entries for MHI

[Bhaumik Bhatt]

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 | 25 ++++++++++++++++
 MAINTAINERS                            |  1 +
 drivers/bus/mhi/core/init.c            | 53 ++++++++++++++++++++++++++++++++++
 3 files changed, 79 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..65ef711
--- /dev/null
+++ b/Documentation/ABI/stable/sysfs-bus-mhi
@@ -0,0 +1,25 @@
+What:		/sys/bus/mhi/devices/.../serialnumber
+Date:		May 2020
+KernelVersion:  5.8
+Contact:	Bhaumik Bhatt <bbhatt@codeaurora.org>
+Description:
+		The file holds the serial number 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 the device
+		hardware information.
+
+What:		/sys/bus/mhi/devices/.../oem_pk_hash
+Date:		May 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 the device
+		hardware information.
diff --git a/MAINTAINERS b/MAINTAINERS
index e64e5db..223a5c7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11019,6 +11019,7 @@ 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/mhi/
+F:	Documentation/ABI/stable/sysfs-bus-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 17e3f7d..dbfb030 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,
@@ -916,6 +966,8 @@ 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;
 
@@ -939,6 +991,7 @@ 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

Re: [PATCH v2 4/6] bus: mhi: core: Introduce debugfs entries and counters for MHI

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 2783 bytes --]

Hi Bhaumik,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on next-20200512]
[cannot apply to linus/master v5.7-rc5 v5.7-rc4 v5.7-rc3 v5.7-rc5]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Bhaumik-Bhatt/Introduce-features-and-debugfs-sysfs-entries-for-MHI/20200513-014548
base:    e098d7762d602be640c53565ceca342f81e55ad2
config: um-allyesconfig (attached as .config)
compiler: gcc-7 (Ubuntu 7.5.0-6ubuntu2) 7.5.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=um 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

drivers/bus/mhi/core/debugfs.c: In function 'mhi_debugfs_trigger_reset':
>> drivers/bus/mhi/core/debugfs.c:294:2: error: implicit declaration of function 'mhi_pm_sys_err_handler'; did you mean 'mhi_pm_sys_err_worker'? [-Werror=implicit-function-declaration]
mhi_pm_sys_err_handler(mhi_cntrl);
^~~~~~~~~~~~~~~~~~~~~~
mhi_pm_sys_err_worker
cc1: some warnings being treated as errors

vim +294 drivers/bus/mhi/core/debugfs.c

   259	
   260	static int mhi_debugfs_trigger_reset(void *data, u64 val)
   261	{
   262		struct mhi_controller *mhi_cntrl = data;
   263		struct mhi_device *mhi_dev = mhi_cntrl->mhi_dev;
   264		struct device *dev = &mhi_dev->dev;
   265		enum mhi_pm_state cur_state;
   266		int ret = -EIO;
   267	
   268		if (!mhi_is_active(mhi_cntrl))
   269			return -ENODEV;
   270	
   271		if (!val)
   272			return -EINVAL;
   273	
   274		ret = mhi_device_get_sync(mhi_dev, MHI_VOTE_DEVICE);
   275		if (ret) {
   276			dev_err(dev, "Device did not enter M0 state, MHI:%s, PM:%s\n",
   277				TO_MHI_STATE_STR(mhi_cntrl->dev_state),
   278				to_mhi_pm_state_str(mhi_cntrl->pm_state));
   279			return ret;
   280		}
   281	
   282		if (mhi_cntrl->rddm_image) {
   283			ret = mhi_force_rddm_mode(mhi_cntrl);
   284			goto exit_mhi_trigger_reset;
   285		}
   286	
   287		write_lock_irq(&mhi_cntrl->pm_lock);
   288		cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_SYS_ERR_DETECT);
   289		write_unlock_irq(&mhi_cntrl->pm_lock);
   290	
   291		if (cur_state != MHI_PM_SYS_ERR_DETECT)
   292			goto exit_mhi_trigger_reset;
   293	
 > 294		mhi_pm_sys_err_handler(mhi_cntrl);
   295		ret = 0;
   296	
   297	exit_mhi_trigger_reset:
   298		mhi_device_put(mhi_dev, MHI_VOTE_DEVICE);
   299	
   300		return ret;
   301	}
   302	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
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Re: [PATCH v2 4/6] bus: mhi: core: Introduce debugfs entries and counters for MHI

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 5139 bytes --]

Hi Bhaumik,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on next-20200512]
[cannot apply to linus/master v5.7-rc5 v5.7-rc4 v5.7-rc3 v5.7-rc5]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Bhaumik-Bhatt/Introduce-features-and-debugfs-sysfs-entries-for-MHI/20200513-014548
base:    e098d7762d602be640c53565ceca342f81e55ad2
config: m68k-allyesconfig (attached as .config)
compiler: m68k-linux-gcc (GCC) 9.3.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day GCC_VERSION=9.3.0 make.cross ARCH=m68k 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

drivers/bus/mhi/core/debugfs.c: In function 'mhi_debugfs_events_show':
>> drivers/bus/mhi/core/debugfs.c:71:33: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
71 |       er_ctxt->rp, er_ctxt->wp, (u64)ring->rp,
|                                 ^
>> drivers/bus/mhi/core/debugfs.c:70:53: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 6 has type 'dma_addr_t' {aka 'unsigned int'} [-Wformat=]
70 |       " rp:0x%llx wp:0x%llx local rp:0x%llx db:0x%llxn",
|                                                  ~~~^
|                                                     |
|                                                     long long unsigned int
|                                                  %x
71 |       er_ctxt->rp, er_ctxt->wp, (u64)ring->rp,
72 |       mhi_event->db_cfg.db_val);
|       ~~~~~~~~~~~~~~~~~~~~~~~~
|                        |
|                        dma_addr_t {aka unsigned int}
drivers/bus/mhi/core/debugfs.c: In function 'mhi_debugfs_channels_show':
drivers/bus/mhi/core/debugfs.c:119:7: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
119 |       (u64)ring->rp, (u64)ring->wp,
|       ^
drivers/bus/mhi/core/debugfs.c:119:22: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
119 |       (u64)ring->rp, (u64)ring->wp,
|                      ^
drivers/bus/mhi/core/debugfs.c:118:59: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 5 has type 'dma_addr_t' {aka 'unsigned int'} [-Wformat=]
118 |   seq_printf(m, " local rp:0x%llx local wp:0x%llx db:0x%llxn",
|                                                        ~~~^
|                                                           |
|                                                           long long unsigned int
|                                                        %x
119 |       (u64)ring->rp, (u64)ring->wp,
120 |       mhi_chan->db_cfg.db_val);
|       ~~~~~~~~~~~~~~~~~~~~~~~
|                       |
|                       dma_addr_t {aka unsigned int}
drivers/bus/mhi/core/debugfs.c: In function 'mhi_debugfs_trigger_reset':
drivers/bus/mhi/core/debugfs.c:294:2: error: implicit declaration of function 'mhi_pm_sys_err_handler'; did you mean 'mhi_pm_sys_err_worker'? [-Werror=implicit-function-declaration]
294 |  mhi_pm_sys_err_handler(mhi_cntrl);
|  ^~~~~~~~~~~~~~~~~~~~~~
|  mhi_pm_sys_err_worker
cc1: some warnings being treated as errors

vim +71 drivers/bus/mhi/core/debugfs.c

    36	
    37	static int mhi_debugfs_events_show(struct seq_file *m, void *d)
    38	{
    39		struct mhi_controller *mhi_cntrl = m->private;
    40		struct mhi_event *mhi_event;
    41		struct mhi_event_ctxt *er_ctxt;
    42		int i;
    43	
    44		if (!mhi_is_active(mhi_cntrl)) {
    45			seq_puts(m, "Device not ready\n");
    46			return -ENODEV;
    47		}
    48	
    49		er_ctxt = mhi_cntrl->mhi_ctxt->er_ctxt;
    50		mhi_event = mhi_cntrl->mhi_event;
    51		for (i = 0; i < mhi_cntrl->total_ev_rings;
    52							i++, er_ctxt++, mhi_event++) {
    53			struct mhi_ring *ring = &mhi_event->ring;
    54	
    55			if (mhi_event->offload_ev) {
    56				seq_printf(m, "Index:%d is an offload event ring\n", i);
    57				continue;
    58			}
    59	
    60			seq_printf(m, "Index:%d intmod count:%lu time:%lu",
    61				   i, (er_ctxt->intmod & EV_CTX_INTMODC_MASK) >>
    62				   EV_CTX_INTMODC_SHIFT,
    63				   (er_ctxt->intmod & EV_CTX_INTMODT_MASK) >>
    64				   EV_CTX_INTMODT_SHIFT);
    65	
    66			seq_printf(m, " base:0x%0llx len:0x%llx", er_ctxt->rbase,
    67				   er_ctxt->rlen);
    68	
    69			seq_printf(m,
  > 70				   " rp:0x%llx wp:0x%llx local rp:0x%llx db:0x%llx\n",
  > 71				   er_ctxt->rp, er_ctxt->wp, (u64)ring->rp,
    72				   mhi_event->db_cfg.db_val);
    73		}
    74	
    75		return 0;
    76	}
    77	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

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