[PATCH v2 0/7] Improvements to MHI Bus

[PATCH v2 0/7] Improvements to MHI Bus

[Manivannan Sadhasivam]

Hi Greg,

Here is the patchset for improving the MHI bus support. One of the patch
is suggested by you for adding the driver owner field and rest are additional
improvements and some fixes.

I've also included the remaining networking patches from previous patch series
which needs review from Dave. Dave could you please look into those 2 patches
which falls under net subsystem? Greg can take those 2 if an Ack is provided.

Thanks,
Mani

Changes in v2:

* Fixed some minor comments in mhi.h

Manivannan Sadhasivam (7):
  bus: mhi: core: Pass module owner during client driver registration
  bus: mhi: core: Add support for reading MHI info from device
  bus: mhi: core: Initialize bhie field in mhi_cntrl for RDDM capture
  bus: mhi: core: Drop the references to mhi_dev in mhi_destroy_device()
  bus: mhi: core: Add support for MHI suspend and resume
  net: qrtr: Add MHI transport layer
  net: qrtr: Do not depend on ARCH_QCOM

 drivers/bus/mhi/core/init.c     |  39 +++++-
 drivers/bus/mhi/core/internal.h |  10 ++
 drivers/bus/mhi/core/main.c     |  16 ++-
 drivers/bus/mhi/core/pm.c       | 143 ++++++++++++++++++++++
 include/linux/mhi.h             |  48 +++++++-
 net/qrtr/Kconfig                |   8 +-
 net/qrtr/Makefile               |   2 +
 net/qrtr/mhi.c                  | 208 ++++++++++++++++++++++++++++++++
 8 files changed, 465 insertions(+), 9 deletions(-)
 create mode 100644 net/qrtr/mhi.c

-- 
2.17.1

[PATCH v2 1/7] bus: mhi: core: Pass module owner during client driver registration

[Manivannan Sadhasivam]

The module owner field can be used to prevent the removal of kernel
modules when there are any device files associated with it opened in
userspace. Hence, modify the API to pass module owner field. For
convenience, module_mhi_driver() macro is used which takes care of
passing the module owner through THIS_MODULE of the module of the
driver and also avoiding the use of specifying the default MHI client
driver register/unregister routines.

Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/init.c |  5 +++--
 include/linux/mhi.h         | 21 +++++++++++++++++++--
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 5fb756ca335e..eb7f556a8531 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -1189,7 +1189,7 @@ static int mhi_driver_remove(struct device *dev)
 	return 0;
 }
 
-int mhi_driver_register(struct mhi_driver *mhi_drv)
+int __mhi_driver_register(struct mhi_driver *mhi_drv, struct module *owner)
 {
 	struct device_driver *driver = &mhi_drv->driver;
 
@@ -1197,12 +1197,13 @@ int mhi_driver_register(struct mhi_driver *mhi_drv)
 		return -EINVAL;
 
 	driver->bus = &mhi_bus_type;
+	driver->owner = owner;
 	driver->probe = mhi_driver_probe;
 	driver->remove = mhi_driver_remove;
 
 	return driver_register(driver);
 }
-EXPORT_SYMBOL_GPL(mhi_driver_register);
+EXPORT_SYMBOL_GPL(__mhi_driver_register);
 
 void mhi_driver_unregister(struct mhi_driver *mhi_drv)
 {
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index 79cb9f898544..d83e7772681b 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -514,11 +514,28 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
  */
 void mhi_unregister_controller(struct mhi_controller *mhi_cntrl);
 
+/*
+ * module_mhi_driver() - Helper macro for drivers that don't do
+ * anything special other than using default mhi_driver_register() and
+ * mhi_driver_unregister().  This eliminates a lot of boilerplate.
+ * Each module may only use this macro once.
+ */
+#define module_mhi_driver(mhi_drv) \
+	module_driver(mhi_drv, mhi_driver_register, \
+		      mhi_driver_unregister)
+
+/*
+ * Macro to avoid include chaining to get THIS_MODULE
+ */
+#define mhi_driver_register(mhi_drv) \
+	__mhi_driver_register(mhi_drv, THIS_MODULE)
+
 /**
- * mhi_driver_register - Register driver with MHI framework
+ * __mhi_driver_register - Register driver with MHI framework
  * @mhi_drv: Driver associated with the device
+ * @owner: The module owner
  */
-int mhi_driver_register(struct mhi_driver *mhi_drv);
+int __mhi_driver_register(struct mhi_driver *mhi_drv, struct module *owner);
 
 /**
  * mhi_driver_unregister - Unregister a driver for mhi_devices
-- 
2.17.1

[PATCH v2 2/7] bus: mhi: core: Add support for reading MHI info from device

[Manivannan Sadhasivam]

The MHI register base has several registers used for getting the MHI
specific information such as version, family, major, and minor numbers
from the device. This information can be used by the controller drivers
for usecases such as applying quirks for a specific revision etc...

While at it, let's also rearrange the local variables
in mhi_register_controller().

Suggested-by: Hemant Kumar <hemantk@codeaurora.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/init.c     | 19 +++++++++++++++++--
 drivers/bus/mhi/core/internal.h | 10 ++++++++++
 include/linux/mhi.h             |  8 ++++++++
 3 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index eb7f556a8531..d136f6c6ca78 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -802,12 +802,12 @@ static int parse_config(struct mhi_controller *mhi_cntrl,
 int mhi_register_controller(struct mhi_controller *mhi_cntrl,
 			    struct mhi_controller_config *config)
 {
-	int ret;
-	int i;
 	struct mhi_event *mhi_event;
 	struct mhi_chan *mhi_chan;
 	struct mhi_cmd *mhi_cmd;
 	struct mhi_device *mhi_dev;
+	u32 soc_info;
+	int ret, i;
 
 	if (!mhi_cntrl)
 		return -EINVAL;
@@ -874,6 +874,21 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
 		mhi_cntrl->unmap_single = mhi_unmap_single_no_bb;
 	}
 
+	/* Read the MHI device info */
+	ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs,
+			   SOC_HW_VERSION_OFFS, &soc_info);
+	if (ret)
+		goto error_alloc_dev;
+
+	mhi_cntrl->family_number = (soc_info & SOC_HW_VERSION_FAM_NUM_BMSK) >>
+					SOC_HW_VERSION_FAM_NUM_SHFT;
+	mhi_cntrl->device_number = (soc_info & SOC_HW_VERSION_DEV_NUM_BMSK) >>
+					SOC_HW_VERSION_DEV_NUM_SHFT;
+	mhi_cntrl->major_version = (soc_info & SOC_HW_VERSION_MAJOR_VER_BMSK) >>
+					SOC_HW_VERSION_MAJOR_VER_SHFT;
+	mhi_cntrl->minor_version = (soc_info & SOC_HW_VERSION_MINOR_VER_BMSK) >>
+					SOC_HW_VERSION_MINOR_VER_SHFT;
+
 	/* Register controller with MHI bus */
 	mhi_dev = mhi_alloc_device(mhi_cntrl);
 	if (IS_ERR(mhi_dev)) {
diff --git a/drivers/bus/mhi/core/internal.h b/drivers/bus/mhi/core/internal.h
index 18066302e6e2..5deadfaa053a 100644
--- a/drivers/bus/mhi/core/internal.h
+++ b/drivers/bus/mhi/core/internal.h
@@ -196,6 +196,16 @@ extern struct bus_type mhi_bus_type;
 #define BHIE_RXVECSTATUS_STATUS_XFER_COMPL (0x02)
 #define BHIE_RXVECSTATUS_STATUS_ERROR (0x03)
 
+#define SOC_HW_VERSION_OFFS (0x224)
+#define SOC_HW_VERSION_FAM_NUM_BMSK (0xF0000000)
+#define SOC_HW_VERSION_FAM_NUM_SHFT (28)
+#define SOC_HW_VERSION_DEV_NUM_BMSK (0x0FFF0000)
+#define SOC_HW_VERSION_DEV_NUM_SHFT (16)
+#define SOC_HW_VERSION_MAJOR_VER_BMSK (0x0000FF00)
+#define SOC_HW_VERSION_MAJOR_VER_SHFT (8)
+#define SOC_HW_VERSION_MINOR_VER_BMSK (0x000000FF)
+#define SOC_HW_VERSION_MINOR_VER_SHFT (0)
+
 #define EV_CTX_RESERVED_MASK GENMASK(7, 0)
 #define EV_CTX_INTMODC_MASK GENMASK(15, 8)
 #define EV_CTX_INTMODC_SHIFT 8
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index d83e7772681b..b295de5b4ab4 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -310,6 +310,10 @@ struct mhi_controller_config {
  * @sw_ev_rings: Number of software event rings
  * @nr_irqs_req: Number of IRQs required to operate (optional)
  * @nr_irqs: Number of IRQ allocated by bus master (required)
+ * @family_number: MHI controller family number
+ * @device_number: MHI controller device number
+ * @major_version: MHI controller major revision number
+ * @minor_version: MHI controller minor revision number
  * @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
@@ -375,6 +379,10 @@ struct mhi_controller {
 	u32 sw_ev_rings;
 	u32 nr_irqs_req;
 	u32 nr_irqs;
+	u32 family_number;
+	u32 device_number;
+	u32 major_version;
+	u32 minor_version;
 
 	struct mhi_event *mhi_event;
 	struct mhi_cmd *mhi_cmd;
-- 
2.17.1

Re: [PATCH v2 2/7] bus: mhi: core: Add support for reading MHI info from device

[Jeffrey Hugo]

On 3/23/2020 6:30 AM, Manivannan Sadhasivam wrote:
> The MHI register base has several registers used for getting the MHI
> specific information such as version, family, major, and minor numbers
> from the device. This information can be used by the controller drivers
> for usecases such as applying quirks for a specific revision etc...
> 
> While at it, let's also rearrange the local variables
> in mhi_register_controller().
> 
> Suggested-by: Hemant Kumar <hemantk@codeaurora.org>
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---
> --- a/include/linux/mhi.h
> +++ b/include/linux/mhi.h
> @@ -310,6 +310,10 @@ struct mhi_controller_config {
>    * @sw_ev_rings: Number of software event rings
>    * @nr_irqs_req: Number of IRQs required to operate (optional)
>    * @nr_irqs: Number of IRQ allocated by bus master (required)
> + * @family_number: MHI controller family number
> + * @device_number: MHI controller device number
> + * @major_version: MHI controller major revision number
> + * @minor_version: MHI controller minor revision number

Maybe expand the comment to indicate there are valid after register() to 
give controller implementations an idea of when they can use these for 
quirks, etc?

>    * @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
> @@ -375,6 +379,10 @@ struct mhi_controller {
>   	u32 sw_ev_rings;
>   	u32 nr_irqs_req;
>   	u32 nr_irqs;
> +	u32 family_number;
> +	u32 device_number;
> +	u32 major_version;
> +	u32 minor_version;
>   
>   	struct mhi_event *mhi_event;
>   	struct mhi_cmd *mhi_cmd;
> 


-- 
Jeffrey Hugo
Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.

Re: [PATCH v2 2/7] bus: mhi: core: Add support for reading MHI info from device

[Manivannan Sadhasivam]

On Mon, Mar 23, 2020 at 08:14:07AM -0600, Jeffrey Hugo wrote:
> On 3/23/2020 6:30 AM, Manivannan Sadhasivam wrote:
> > The MHI register base has several registers used for getting the MHI
> > specific information such as version, family, major, and minor numbers
> > from the device. This information can be used by the controller drivers
> > for usecases such as applying quirks for a specific revision etc...
> > 
> > While at it, let's also rearrange the local variables
> > in mhi_register_controller().
> > 
> > Suggested-by: Hemant Kumar <hemantk@codeaurora.org>
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > ---
> > --- a/include/linux/mhi.h
> > +++ b/include/linux/mhi.h
> > @@ -310,6 +310,10 @@ struct mhi_controller_config {
> >    * @sw_ev_rings: Number of software event rings
> >    * @nr_irqs_req: Number of IRQs required to operate (optional)
> >    * @nr_irqs: Number of IRQ allocated by bus master (required)
> > + * @family_number: MHI controller family number
> > + * @device_number: MHI controller device number
> > + * @major_version: MHI controller major revision number
> > + * @minor_version: MHI controller minor revision number
> 
> Maybe expand the comment to indicate there are valid after register() to
> give controller implementations an idea of when they can use these for
> quirks, etc?
> 

Hmm, Okay. Will add a note in next revision.

Thanks,
Mani

> >    * @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
> > @@ -375,6 +379,10 @@ struct mhi_controller {
> >   	u32 sw_ev_rings;
> >   	u32 nr_irqs_req;
> >   	u32 nr_irqs;
> > +	u32 family_number;
> > +	u32 device_number;
> > +	u32 major_version;
> > +	u32 minor_version;
> >   	struct mhi_event *mhi_event;
> >   	struct mhi_cmd *mhi_cmd;
> > 
> 
> 
> -- 
> Jeffrey Hugo
> Qualcomm Technologies, Inc. is a member of the
> Code Aurora Forum, a Linux Foundation Collaborative Project.

[PATCH v2 3/7] bus: mhi: core: Initialize bhie field in mhi_cntrl for RDDM capture

[Manivannan Sadhasivam]

The bhie field in mhi_cntrl needs to be initialized to proper register
base in order to make mhi_rddm_prepare() to work. Otherwise,
mhi_rddm_prepare() will cause NULL pointer dereference.

Fixes: 6fdfdd27328c ("bus: mhi: core: Add support for downloading RDDM image during panic")
Reported-by: Hemant Kumar <hemantk@codeaurora.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/init.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index d136f6c6ca78..f6e3c16225a7 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -979,7 +979,8 @@ int mhi_prepare_for_power_up(struct mhi_controller *mhi_cntrl)
 			goto bhie_error;
 		}
 
-		memset_io(mhi_cntrl->regs + bhie_off + BHIE_RXVECADDR_LOW_OFFS,
+		mhi_cntrl->bhie = mhi_cntrl->regs + bhie_off;
+		memset_io(mhi_cntrl->bhie + BHIE_RXVECADDR_LOW_OFFS,
 			  0, BHIE_RXVECSTATUS_OFFS - BHIE_RXVECADDR_LOW_OFFS +
 			  4);
 
-- 
2.17.1

[PATCH v2 4/7] bus: mhi: core: Drop the references to mhi_dev in mhi_destroy_device()

[Manivannan Sadhasivam]

For some scenarios like controller suspend and resume, mhi_destroy_device()
will get called without mhi_unregister_controller(). In that case, the
references to the mhi_dev created for the channels will not be dropped
but the channels will be destroyed as per the spec. This will cause issue
during resume as the channels will not be created due to the fact that
mhi_dev is not NULL.

Hence, this change decrements the refcount for mhi_dev in
mhi_destroy_device() for concerned channels and also sets mhi_dev to NULL
in release_device().

Reported-by: Carl Huang <cjhuang@codeaurora.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/init.c | 12 ++++++++++++
 drivers/bus/mhi/core/main.c | 13 +++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index f6e3c16225a7..b38359c480ea 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -1028,6 +1028,18 @@ static void mhi_release_device(struct device *dev)
 {
 	struct mhi_device *mhi_dev = to_mhi_device(dev);
 
+	/*
+	 * We need to set the mhi_chan->mhi_dev to NULL here since the MHI
+	 * devices for the channels will only get created if the mhi_dev
+	 * associated with it is NULL. This scenario will happen during the
+	 * controller suspend and resume.
+	 */
+	if (mhi_dev->ul_chan)
+		mhi_dev->ul_chan->mhi_dev = NULL;
+
+	if (mhi_dev->dl_chan)
+		mhi_dev->dl_chan->mhi_dev = NULL;
+
 	kfree(mhi_dev);
 }
 
diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
index fa1c9000fc6c..eb4256b81406 100644
--- a/drivers/bus/mhi/core/main.c
+++ b/drivers/bus/mhi/core/main.c
@@ -244,6 +244,19 @@ int mhi_destroy_device(struct device *dev, void *data)
 	if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER)
 		return 0;
 
+	/*
+	 * For the suspend and resume case, this function will get called
+	 * without mhi_unregister_controller(). Hence, we need to drop the
+	 * references to mhi_dev created for ul and dl channels. We can
+	 * be sure that there will be no instances of mhi_dev left after
+	 * this.
+	 */
+	if (mhi_dev->ul_chan)
+		put_device(&mhi_dev->ul_chan->mhi_dev->dev);
+
+	if (mhi_dev->dl_chan)
+		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);
 
-- 
2.17.1

[PATCH v2 5/7] bus: mhi: core: Add support for MHI suspend and resume

[Manivannan Sadhasivam]

Add support for MHI suspend and resume states. While at it, the
mhi_notify() function needs to be exported as well.

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/main.c |   3 +-
 drivers/bus/mhi/core/pm.c   | 143 ++++++++++++++++++++++++++++++++++++
 include/linux/mhi.h         |  19 +++++
 3 files changed, 164 insertions(+), 1 deletion(-)

diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
index eb4256b81406..3e9aa3b2da77 100644
--- a/drivers/bus/mhi/core/main.c
+++ b/drivers/bus/mhi/core/main.c
@@ -267,7 +267,7 @@ int mhi_destroy_device(struct device *dev, void *data)
 	return 0;
 }
 
-static void mhi_notify(struct mhi_device *mhi_dev, enum mhi_callback cb_reason)
+void mhi_notify(struct mhi_device *mhi_dev, enum mhi_callback cb_reason)
 {
 	struct mhi_driver *mhi_drv;
 
@@ -279,6 +279,7 @@ static void mhi_notify(struct mhi_device *mhi_dev, enum mhi_callback cb_reason)
 	if (mhi_drv->status_cb)
 		mhi_drv->status_cb(mhi_dev, cb_reason);
 }
+EXPORT_SYMBOL_GPL(mhi_notify);
 
 /* Bind MHI channels to MHI devices */
 void mhi_create_devices(struct mhi_controller *mhi_cntrl)
diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index 52690cb5c89c..3529419d076b 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -669,6 +669,149 @@ 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;
+	enum mhi_pm_state new_state;
+	int ret;
+
+	if (mhi_cntrl->pm_state == MHI_PM_DISABLE)
+		return -EINVAL;
+
+	if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state))
+		return -EIO;
+
+	/* Return busy if there are any pending resources */
+	if (atomic_read(&mhi_cntrl->dev_wake))
+		return -EBUSY;
+
+	/* Take MHI out of M2 state */
+	read_lock_bh(&mhi_cntrl->pm_lock);
+	mhi_cntrl->wake_get(mhi_cntrl, false);
+	read_unlock_bh(&mhi_cntrl->pm_lock);
+
+	ret = wait_event_timeout(mhi_cntrl->state_event,
+				 mhi_cntrl->dev_state == MHI_STATE_M0 ||
+				 mhi_cntrl->dev_state == MHI_STATE_M1 ||
+				 MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state),
+				 msecs_to_jiffies(mhi_cntrl->timeout_ms));
+
+	read_lock_bh(&mhi_cntrl->pm_lock);
+	mhi_cntrl->wake_put(mhi_cntrl, false);
+	read_unlock_bh(&mhi_cntrl->pm_lock);
+
+	if (!ret || MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
+		dev_err(dev,
+			"Could not enter M0/M1 state");
+		return -EIO;
+	}
+
+	write_lock_irq(&mhi_cntrl->pm_lock);
+
+	if (atomic_read(&mhi_cntrl->dev_wake)) {
+		write_unlock_irq(&mhi_cntrl->pm_lock);
+		return -EBUSY;
+	}
+
+	dev_info(dev, "Allowing M3 transition\n");
+	new_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_M3_ENTER);
+	if (new_state != MHI_PM_M3_ENTER) {
+		write_unlock_irq(&mhi_cntrl->pm_lock);
+		dev_err(dev,
+			"Error setting to PM state: %s from: %s\n",
+			to_mhi_pm_state_str(MHI_PM_M3_ENTER),
+			to_mhi_pm_state_str(mhi_cntrl->pm_state));
+		return -EIO;
+	}
+
+	/* Set MHI to M3 and wait for completion */
+	mhi_set_mhi_state(mhi_cntrl, MHI_STATE_M3);
+	write_unlock_irq(&mhi_cntrl->pm_lock);
+	dev_info(dev, "Wait for M3 completion\n");
+
+	ret = wait_event_timeout(mhi_cntrl->state_event,
+				 mhi_cntrl->dev_state == MHI_STATE_M3 ||
+				 MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state),
+				 msecs_to_jiffies(mhi_cntrl->timeout_ms));
+
+	if (!ret || MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
+		dev_err(dev,
+			"Did not enter M3 state, MHI state: %s, PM state: %s\n",
+			TO_MHI_STATE_STR(mhi_cntrl->dev_state),
+			to_mhi_pm_state_str(mhi_cntrl->pm_state));
+		return -EIO;
+	}
+
+	/* Notify clients about entering LPM */
+	list_for_each_entry_safe(itr, tmp, &mhi_cntrl->lpm_chans, node) {
+		mutex_lock(&itr->mutex);
+		if (itr->mhi_dev)
+			mhi_notify(itr->mhi_dev, MHI_CB_LPM_ENTER);
+		mutex_unlock(&itr->mutex);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(mhi_pm_suspend);
+
+int mhi_pm_resume(struct mhi_controller *mhi_cntrl)
+{
+	struct mhi_chan *itr, *tmp;
+	struct device *dev = &mhi_cntrl->mhi_dev->dev;
+	enum mhi_pm_state cur_state;
+	int ret;
+
+	dev_info(dev, "Entered with PM state: %s, MHI state: %s\n",
+		 to_mhi_pm_state_str(mhi_cntrl->pm_state),
+		 TO_MHI_STATE_STR(mhi_cntrl->dev_state));
+
+	if (mhi_cntrl->pm_state == MHI_PM_DISABLE)
+		return 0;
+
+	if (MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state))
+		return -EIO;
+
+	/* Notify clients about exiting LPM */
+	list_for_each_entry_safe(itr, tmp, &mhi_cntrl->lpm_chans, node) {
+		mutex_lock(&itr->mutex);
+		if (itr->mhi_dev)
+			mhi_notify(itr->mhi_dev, MHI_CB_LPM_EXIT);
+		mutex_unlock(&itr->mutex);
+	}
+
+	write_lock_irq(&mhi_cntrl->pm_lock);
+	cur_state = mhi_tryset_pm_state(mhi_cntrl, MHI_PM_M3_EXIT);
+	if (cur_state != MHI_PM_M3_EXIT) {
+		write_unlock_irq(&mhi_cntrl->pm_lock);
+		dev_info(dev,
+			 "Error setting to PM state: %s from: %s\n",
+			 to_mhi_pm_state_str(MHI_PM_M3_EXIT),
+			 to_mhi_pm_state_str(mhi_cntrl->pm_state));
+		return -EIO;
+	}
+
+	/* Set MHI to M0 and wait for completion */
+	mhi_set_mhi_state(mhi_cntrl, MHI_STATE_M0);
+	write_unlock_irq(&mhi_cntrl->pm_lock);
+
+	ret = wait_event_timeout(mhi_cntrl->state_event,
+				 mhi_cntrl->dev_state == MHI_STATE_M0 ||
+				 MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state),
+				 msecs_to_jiffies(mhi_cntrl->timeout_ms));
+
+	if (!ret || MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
+		dev_err(dev,
+			"Did not enter M0 state, MHI state: %s, PM state: %s\n",
+			TO_MHI_STATE_STR(mhi_cntrl->dev_state),
+			to_mhi_pm_state_str(mhi_cntrl->pm_state));
+		return -EIO;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(mhi_pm_resume);
+
 int __mhi_device_get_sync(struct mhi_controller *mhi_cntrl)
 {
 	int ret;
diff --git a/include/linux/mhi.h b/include/linux/mhi.h
index b295de5b4ab4..b5f450420245 100644
--- a/include/linux/mhi.h
+++ b/include/linux/mhi.h
@@ -559,6 +559,13 @@ void mhi_driver_unregister(struct mhi_driver *mhi_drv);
 void mhi_set_mhi_state(struct mhi_controller *mhi_cntrl,
 		       enum mhi_state state);
 
+/**
+ * mhi_notify - Notify the MHI client driver about client device status
+ * @mhi_dev: MHI device instance
+ * @cb_reason: MHI callback reason
+ */
+void mhi_notify(struct mhi_device *mhi_dev, enum mhi_callback cb_reason);
+
 /**
  * mhi_prepare_for_power_up - Do pre-initialization before power up.
  *                            This is optional, call this before power up if
@@ -595,6 +602,18 @@ void mhi_power_down(struct mhi_controller *mhi_cntrl, bool graceful);
  */
 void mhi_unprepare_after_power_down(struct mhi_controller *mhi_cntrl);
 
+/**
+ * mhi_pm_suspend - Move MHI into a suspended state
+ * @mhi_cntrl: MHI controller
+ */
+int mhi_pm_suspend(struct mhi_controller *mhi_cntrl);
+
+/**
+ * mhi_pm_resume - Resume MHI from suspended state
+ * @mhi_cntrl: MHI controller
+ */
+int mhi_pm_resume(struct mhi_controller *mhi_cntrl);
+
 /**
  * mhi_download_rddm_img - Download ramdump image from device for
  *                         debugging purpose.
-- 
2.17.1

[PATCH v2 6/7] net: qrtr: Add MHI transport layer

[Manivannan Sadhasivam]

MHI is the transport layer used for communicating to the external modems.
Hence, this commit adds MHI transport layer support to QRTR for
transferring the QMI messages over IPC Router.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 net/qrtr/Kconfig  |   7 ++
 net/qrtr/Makefile |   2 +
 net/qrtr/mhi.c    | 208 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 217 insertions(+)
 create mode 100644 net/qrtr/mhi.c

diff --git a/net/qrtr/Kconfig b/net/qrtr/Kconfig
index 63f89cc6e82c..8eb876471564 100644
--- a/net/qrtr/Kconfig
+++ b/net/qrtr/Kconfig
@@ -29,4 +29,11 @@ config QRTR_TUN
 	  implement endpoints of QRTR, for purpose of tunneling data to other
 	  hosts or testing purposes.
 
+config QRTR_MHI
+	tristate "MHI IPC Router channels"
+	depends on MHI_BUS
+	help
+	  Say Y here to support MHI based ipcrouter channels. MHI is the
+	  transport used for communicating to external modems.
+
 endif # QRTR
diff --git a/net/qrtr/Makefile b/net/qrtr/Makefile
index 1c6d6c120fb7..3dc0a7c9d455 100644
--- a/net/qrtr/Makefile
+++ b/net/qrtr/Makefile
@@ -5,3 +5,5 @@ obj-$(CONFIG_QRTR_SMD) += qrtr-smd.o
 qrtr-smd-y	:= smd.o
 obj-$(CONFIG_QRTR_TUN) += qrtr-tun.o
 qrtr-tun-y	:= tun.o
+obj-$(CONFIG_QRTR_MHI) += qrtr-mhi.o
+qrtr-mhi-y	:= mhi.o
diff --git a/net/qrtr/mhi.c b/net/qrtr/mhi.c
new file mode 100644
index 000000000000..90af208f34c1
--- /dev/null
+++ b/net/qrtr/mhi.c
@@ -0,0 +1,208 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/mhi.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+
+#include "qrtr.h"
+
+struct qrtr_mhi_dev {
+	struct qrtr_endpoint ep;
+	struct mhi_device *mhi_dev;
+	struct device *dev;
+	spinlock_t ul_lock;		/* lock to protect ul_pkts */
+	struct list_head ul_pkts;
+	atomic_t in_reset;
+};
+
+struct qrtr_mhi_pkt {
+	struct list_head node;
+	struct sk_buff *skb;
+	struct kref refcount;
+	struct completion done;
+};
+
+static void qrtr_mhi_pkt_release(struct kref *ref)
+{
+	struct qrtr_mhi_pkt *pkt = container_of(ref, struct qrtr_mhi_pkt,
+						refcount);
+	struct sock *sk = pkt->skb->sk;
+
+	consume_skb(pkt->skb);
+	if (sk)
+		sock_put(sk);
+
+	kfree(pkt);
+}
+
+/* From MHI to QRTR */
+static void qcom_mhi_qrtr_dl_callback(struct mhi_device *mhi_dev,
+				      struct mhi_result *mhi_res)
+{
+	struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);
+	int rc;
+
+	if (!qdev || mhi_res->transaction_status)
+		return;
+
+	rc = qrtr_endpoint_post(&qdev->ep, mhi_res->buf_addr,
+				mhi_res->bytes_xferd);
+	if (rc == -EINVAL)
+		dev_err(qdev->dev, "invalid ipcrouter packet\n");
+}
+
+/* From QRTR to MHI */
+static void qcom_mhi_qrtr_ul_callback(struct mhi_device *mhi_dev,
+				      struct mhi_result *mhi_res)
+{
+	struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);
+	struct qrtr_mhi_pkt *pkt;
+	unsigned long flags;
+
+	spin_lock_irqsave(&qdev->ul_lock, flags);
+	pkt = list_first_entry(&qdev->ul_pkts, struct qrtr_mhi_pkt, node);
+	list_del(&pkt->node);
+	complete_all(&pkt->done);
+
+	kref_put(&pkt->refcount, qrtr_mhi_pkt_release);
+	spin_unlock_irqrestore(&qdev->ul_lock, flags);
+}
+
+static void qcom_mhi_qrtr_status_callback(struct mhi_device *mhi_dev,
+					  enum mhi_callback mhi_cb)
+{
+	struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);
+	struct qrtr_mhi_pkt *pkt;
+	unsigned long flags;
+
+	if (mhi_cb != MHI_CB_FATAL_ERROR)
+		return;
+
+	atomic_inc(&qdev->in_reset);
+	spin_lock_irqsave(&qdev->ul_lock, flags);
+	list_for_each_entry(pkt, &qdev->ul_pkts, node)
+		complete_all(&pkt->done);
+	spin_unlock_irqrestore(&qdev->ul_lock, flags);
+}
+
+/* Send data over MHI */
+static int qcom_mhi_qrtr_send(struct qrtr_endpoint *ep, struct sk_buff *skb)
+{
+	struct qrtr_mhi_dev *qdev = container_of(ep, struct qrtr_mhi_dev, ep);
+	struct qrtr_mhi_pkt *pkt;
+	int rc;
+
+	rc = skb_linearize(skb);
+	if (rc) {
+		kfree_skb(skb);
+		return rc;
+	}
+
+	pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
+	if (!pkt) {
+		kfree_skb(skb);
+		return -ENOMEM;
+	}
+
+	init_completion(&pkt->done);
+	kref_init(&pkt->refcount);
+	kref_get(&pkt->refcount);
+	pkt->skb = skb;
+
+	spin_lock_bh(&qdev->ul_lock);
+	list_add_tail(&pkt->node, &qdev->ul_pkts);
+	rc = mhi_queue_skb(qdev->mhi_dev, DMA_TO_DEVICE, skb, skb->len,
+			   MHI_EOT);
+	if (rc) {
+		list_del(&pkt->node);
+		/* Reference count needs to be dropped 2 times */
+		kref_put(&pkt->refcount, qrtr_mhi_pkt_release);
+		kref_put(&pkt->refcount, qrtr_mhi_pkt_release);
+		kfree_skb(skb);
+		spin_unlock_bh(&qdev->ul_lock);
+		return rc;
+	}
+
+	spin_unlock_bh(&qdev->ul_lock);
+	if (skb->sk)
+		sock_hold(skb->sk);
+
+	rc = wait_for_completion_interruptible_timeout(&pkt->done, HZ * 5);
+	if (atomic_read(&qdev->in_reset))
+		rc = -ECONNRESET;
+	else if (rc == 0)
+		rc = -ETIMEDOUT;
+	else if (rc > 0)
+		rc = 0;
+
+	kref_put(&pkt->refcount, qrtr_mhi_pkt_release);
+
+	return rc;
+}
+
+static int qcom_mhi_qrtr_probe(struct mhi_device *mhi_dev,
+			       const struct mhi_device_id *id)
+{
+	struct qrtr_mhi_dev *qdev;
+	u32 net_id;
+	int rc;
+
+	qdev = devm_kzalloc(&mhi_dev->dev, sizeof(*qdev), GFP_KERNEL);
+	if (!qdev)
+		return -ENOMEM;
+
+	qdev->mhi_dev = mhi_dev;
+	qdev->dev = &mhi_dev->dev;
+	qdev->ep.xmit = qcom_mhi_qrtr_send;
+	atomic_set(&qdev->in_reset, 0);
+
+	net_id = QRTR_EP_NID_AUTO;
+
+	INIT_LIST_HEAD(&qdev->ul_pkts);
+	spin_lock_init(&qdev->ul_lock);
+
+	dev_set_drvdata(&mhi_dev->dev, qdev);
+	rc = qrtr_endpoint_register(&qdev->ep, net_id);
+	if (rc)
+		return rc;
+
+	dev_dbg(qdev->dev, "Qualcomm MHI QRTR driver probed\n");
+
+	return 0;
+}
+
+static void qcom_mhi_qrtr_remove(struct mhi_device *mhi_dev)
+{
+	struct qrtr_mhi_dev *qdev = dev_get_drvdata(&mhi_dev->dev);
+
+	qrtr_endpoint_unregister(&qdev->ep);
+	dev_set_drvdata(&mhi_dev->dev, NULL);
+}
+
+static const struct mhi_device_id qcom_mhi_qrtr_id_table[] = {
+	{ .chan = "IPCR" },
+	{}
+};
+MODULE_DEVICE_TABLE(mhi, qcom_mhi_qrtr_id_table);
+
+static struct mhi_driver qcom_mhi_qrtr_driver = {
+	.probe = qcom_mhi_qrtr_probe,
+	.remove = qcom_mhi_qrtr_remove,
+	.dl_xfer_cb = qcom_mhi_qrtr_dl_callback,
+	.ul_xfer_cb = qcom_mhi_qrtr_ul_callback,
+	.status_cb = qcom_mhi_qrtr_status_callback,
+	.id_table = qcom_mhi_qrtr_id_table,
+	.driver = {
+		.name = "qcom_mhi_qrtr",
+	},
+};
+
+module_mhi_driver(qcom_mhi_qrtr_driver);
+
+MODULE_DESCRIPTION("Qualcomm IPC-Router MHI interface driver");
+MODULE_LICENSE("GPL v2");
-- 
2.17.1

[PATCH v2 7/7] net: qrtr: Do not depend on ARCH_QCOM

[Manivannan Sadhasivam]

IPC Router protocol is also used by external modems for exchanging the QMI
messages. Hence, it doesn't always depend on Qualcomm platforms. One such
instance is the QCA6390 modem connected to x86 machine.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 net/qrtr/Kconfig | 1 -
 1 file changed, 1 deletion(-)

diff --git a/net/qrtr/Kconfig b/net/qrtr/Kconfig
index 8eb876471564..f362ca316015 100644
--- a/net/qrtr/Kconfig
+++ b/net/qrtr/Kconfig
@@ -4,7 +4,6 @@
 
 config QRTR
 	tristate "Qualcomm IPC Router support"
-	depends on ARCH_QCOM || COMPILE_TEST
 	---help---
 	  Say Y if you intend to use Qualcomm IPC router protocol.  The
 	  protocol is used to communicate with services provided by other
-- 
2.17.1

Re: [PATCH v2 7/7] net: qrtr: Do not depend on ARCH_QCOM

[Kalle Valo]

Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> writes:

> IPC Router protocol is also used by external modems for exchanging the QMI
> messages. Hence, it doesn't always depend on Qualcomm platforms. One such
> instance is the QCA6390 modem connected to x86 machine.

QCA6390 is not a modem, it's a Wi-Fi 6 (802.11ax) device :)

-- 
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

Re: [PATCH v2 7/7] net: qrtr: Do not depend on ARCH_QCOM

[Manivannan Sadhasivam]

On Mon, Mar 23, 2020 at 06:30:07PM +0200, Kalle Valo wrote:
> Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> writes:
> 
> > IPC Router protocol is also used by external modems for exchanging the QMI
> > messages. Hence, it doesn't always depend on Qualcomm platforms. One such
> > instance is the QCA6390 modem connected to x86 machine.
> 
> QCA6390 is not a modem, it's a Wi-Fi 6 (802.11ax) device :)
> 

Ah, yes ;) Will fix it in next revision.

Thanks,
Mani

> -- 
> https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches