Commit c7bd825e authored by Bhaumik Bhatt's avatar Bhaumik Bhatt Committed by Greg Kroah-Hartman
Browse files

bus: mhi: core: Introduce debugfs entries for MHI 



Introduce debugfs entries to show state, register, channel, device,
and event rings information. Allow the host to dump registers,
issue device wake, and change the MHI timeout to help in debug.

Reviewed-by: default avatarManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: default avatarBhaumik Bhatt <bbhatt@codeaurora.org>
Signed-off-by: default avatarManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20200929175218.8178-15-manivannan.sadhasivam@linaro.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent e0af24ac

drivers/bus/mhi/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -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.

drivers/bus/mhi/core/Makefile

+1 −0
Original line number Diff line number Diff line 
obj-$(CONFIG_MHI_BUS) := mhi.o



mhi-y := init.o main.o pm.o boot.o

mhi-$(CONFIG_MHI_BUS_DEBUG) += debugfs.o

drivers/bus/mhi/core/debugfs.c

0 → 100644
+410 −0
Original line number Diff line number Diff line 
// 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 <linux/module.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", mhi_cntrl->M0, mhi_cntrl->M2,

		   mhi_cntrl->M3);



	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", er_ctxt->rp,

			   er_ctxt->wp);



		seq_printf(m, " local rp: 0x%pK db: 0x%pad\n", 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%pK local wp: 0x%pK db: 0x%pad\n",

			   ring->rp, ring->wp,

			   &mhi_chan->db_cfg.db_val);

	}



	return 0;

}



static int mhi_device_info_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: type: %s dev_wake: %u",

		   mhi_dev->name, mhi_dev->dev_type ? "Controller" : "Transfer",

		   mhi_dev->dev_wake);



	/* for transfer device types only */

	if (mhi_dev->dev_type == MHI_DEVICE_XFER)

		seq_printf((struct seq_file *)data, " channels: %u(UL)/%u(DL)",

			   mhi_dev->ul_chan_id, mhi_dev->dl_chan_id);



	seq_puts((struct seq_file *)data, "\n");



	return 0;

}



static int mhi_debugfs_devices_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_info_show);



	return 0;

}



static int mhi_debugfs_regdump_show(struct seq_file *m, void *d)

{

	struct mhi_controller *mhi_cntrl = m->private;

	enum mhi_state state;

	enum mhi_ee_type ee;

	int i, ret = -EIO;

	u32 val;

	void __iomem *mhi_base = mhi_cntrl->regs;

	void __iomem *bhi_base = mhi_cntrl->bhi;

	void __iomem *bhie_base = mhi_cntrl->bhie;

	void __iomem *wake_db = mhi_cntrl->wake_db;

	struct {

		const char *name;

		int offset;

		void __iomem *base;

	} regs[] = {

		{ "MHI_REGLEN", MHIREGLEN, mhi_base},

		{ "MHI_VER", MHIVER, mhi_base},

		{ "MHI_CFG", MHICFG, mhi_base},

		{ "MHI_CTRL", MHICTRL, mhi_base},

		{ "MHI_STATUS", MHISTATUS, mhi_base},

		{ "MHI_WAKE_DB", 0, wake_db},

		{ "BHI_EXECENV", BHI_EXECENV, bhi_base},

		{ "BHI_STATUS", BHI_STATUS, bhi_base},

		{ "BHI_ERRCODE", BHI_ERRCODE, bhi_base},

		{ "BHI_ERRDBG1", BHI_ERRDBG1, bhi_base},

		{ "BHI_ERRDBG2", BHI_ERRDBG2, bhi_base},

		{ "BHI_ERRDBG3", BHI_ERRDBG3, bhi_base},

		{ "BHIE_TXVEC_DB", BHIE_TXVECDB_OFFS, bhie_base},

		{ "BHIE_TXVEC_STATUS", BHIE_TXVECSTATUS_OFFS, bhie_base},

		{ "BHIE_RXVEC_DB", BHIE_RXVECDB_OFFS, bhie_base},

		{ "BHIE_RXVEC_STATUS", BHIE_RXVECSTATUS_OFFS, bhie_base},

		{ NULL },

	};



	if (!MHI_REG_ACCESS_VALID(mhi_cntrl->pm_state))

		return ret;



	seq_printf(m, "Host PM state: %s Device state: %s EE: %s\n",

		   to_mhi_pm_state_str(mhi_cntrl->pm_state),

		   TO_MHI_STATE_STR(mhi_cntrl->dev_state),

		   TO_MHI_EXEC_STR(mhi_cntrl->ee));



	state = mhi_get_mhi_state(mhi_cntrl);

	ee = mhi_get_exec_env(mhi_cntrl);

	seq_printf(m, "Device EE: %s state: %s\n", TO_MHI_EXEC_STR(ee),

		   TO_MHI_STATE_STR(state));



	for (i = 0; regs[i].name; i++) {

		if (!regs[i].base)

			continue;

		ret = mhi_read_reg(mhi_cntrl, regs[i].base, regs[i].offset,

				   &val);

		if (ret)

			continue;



		seq_printf(m, "%s: 0x%x\n", regs[i].name, val);

	}



	return 0;

}



static int mhi_debugfs_device_wake_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,

		   "Wake count: %d\n%s\n", mhi_dev->dev_wake,

		   "Usage: echo get/put > device_wake to vote/unvote for M0");



	return 0;

}



static ssize_t mhi_debugfs_device_wake_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[16];

	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);

	} else if (!strncmp(buf, "put", 3)) {

		mhi_device_put(mhi_dev);

		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_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_devices_open(struct inode *inode, struct file *fp)

{

	return single_open(fp, mhi_debugfs_devices_show, inode->i_private);

}



static int mhi_debugfs_regdump_open(struct inode *inode, struct file *fp)

{

	return single_open(fp, mhi_debugfs_regdump_show, inode->i_private);

}



static int mhi_debugfs_device_wake_open(struct inode *inode, struct file *fp)

{

	return single_open(fp, mhi_debugfs_device_wake_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_devices_fops = {

	.open = mhi_debugfs_devices_open,

	.release = single_release,

	.read = seq_read,

};



static const struct file_operations debugfs_regdump_fops = {

	.open = mhi_debugfs_regdump_open,

	.release = single_release,

	.read = seq_read,

};



static const struct file_operations debugfs_device_wake_fops = {

	.open = mhi_debugfs_device_wake_open,

	.write = mhi_debugfs_device_wake_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,

};



static struct dentry *mhi_debugfs_root;



void mhi_create_debugfs(struct mhi_controller *mhi_cntrl)

{

	mhi_cntrl->debugfs_dentry =

			debugfs_create_dir(dev_name(mhi_cntrl->cntrl_dev),

					   mhi_debugfs_root);



	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("devices", 0444, mhi_cntrl->debugfs_dentry,

			    mhi_cntrl, &debugfs_devices_fops);

	debugfs_create_file("regdump", 0444, mhi_cntrl->debugfs_dentry,

			    mhi_cntrl, &debugfs_regdump_fops);

	debugfs_create_file("device_wake", 0644, mhi_cntrl->debugfs_dentry,

			    mhi_cntrl, &debugfs_device_wake_fops);

	debugfs_create_file("timeout_ms", 0644, mhi_cntrl->debugfs_dentry,

			    mhi_cntrl, &debugfs_timeout_ms_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);

}

drivers/bus/mhi/core/init.c

+7 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
 *

 */



#include <linux/debugfs.h>

#include <linux/device.h>

#include <linux/dma-direction.h>

#include <linux/dma-mapping.h>
@@ -915,6 +916,8 @@ 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:
@@ -937,6 +940,8 @@ 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);
@@ -1300,11 +1305,13 @@ 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);

}

drivers/bus/mhi/core/internal.h

+24 −0
Original line number Diff line number Diff line
@@ -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);