msm-core: Add debugfs support to the driver

obj-$(CONFIG_MSM_IDLE_STATS)	+= lpm-stats.o

obj-$(CONFIG_MSM_NOPM)		+= no-pm.o

obj-$(CONFIG_PM)		+= pm-boot.o

obj-$(CONFIG_APSS_CORE_EA)	+= msm-core.o

obj-$(CONFIG_APSS_CORE_EA)	+= msm-core.o debug_core.o

/* Copyright (c) 2014, The Linux Foundation. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 and

 * only version 2 as published by the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 */

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/slab.h>

#include <linux/uaccess.h>

#include <linux/string.h>

#include <linux/debugfs.h>

#include <linux/ctype.h>

#include <linux/cpu.h>

#define MAX_PSTATES 20

enum arg_offset {

	CPU_OFFSET,

	FREQ_OFFSET,

	POWER_OFFSET,

};

struct core_debug {

	int cpu;

	struct cpu_pstate_pwr *head;

	int enabled;

	int len;

	struct cpu_pwr_stats *ptr;

	struct cpu_pstate_pwr *driver_data;

	int driver_len;

};

static DEFINE_PER_CPU(struct core_debug, c_dgfs);

static struct cpu_pwr_stats *msm_core_data;

static struct debugfs_blob_wrapper help_msg = {

	.data =

"MSM CORE Debug-FS Support\n"

"\n"

"Hierarchy schema\n"

"/sys/kernel/debug/msm_core\n"

"  /help        - Static help text\n"

"  /ptable      - write to p-state table\n"

"  /enable      - enable the written p-state table\n"

"  /ptable_dump - Dump the debug ptable\n"

"\n"

"Usage\n"

" Input test frequency and power information in ptable:\n"

" echo \"0 300000 120\" > ptable\n"

" format: <cpu> <frequency in khz> <power>\n"

"\n"

" Enable the ptable for the cpu:\n"

" echo \"0 1\" > enable\n"

" format: <cpu> <1 to enable, 0 to disable>\n"

" Note: Writing 0 to disable will reset/clear the ptable\n"

"\n"

" Dump the entire ptable:\n"

" cat ptable\n"

" -----  CPU0 - Enabled ---------\n"

"     Freq       Power\n"

"     700000       120\n"

"-----  CPU0 - Live numbers -----\n"

"   Freq       Power\n"

"   300000      218\n"

" -----  CPU1 - Written ---------\n"

"     Freq       Power\n"

"     700000       120\n"

" Ptable dump will dump the status of the table as well\n"

" It shows:\n"

" Enabled -> for a cpu that debug ptable enabled\n"

" Written -> for a cpu that has debug ptable values written\n"

"            but not enabled\n"

"\n",

};

static void add_to_ptable(uint64_t *arg)

{

	struct core_debug *node;

	int i, cpu = arg[CPU_OFFSET];

	if (!cpu_possible(cpu))

		return;

	node = &per_cpu(c_dgfs, cpu);

	if (!node->head) {

		node->head = kzalloc(sizeof(struct cpu_pstate_pwr) *

				     (MAX_PSTATES + 1),

					GFP_KERNEL);

		if (!node->head)

			return;

	}

	for (i = 0; i < MAX_PSTATES; i++) {

		if (node->head[i].freq == arg[FREQ_OFFSET]) {

			node->head[i].power = arg[POWER_OFFSET];

			return;

		}

		if (node->head[i].freq == 0)

			break;

	}

	if (i == MAX_PSTATES) {

		pr_warn("Dropped ptable update - no space left.\n");

		return;

	}

	/* Insert a new frequency (may need to move things around to

	   keep in ascending order). */

	for (i = MAX_PSTATES - 1; i > 0; i--) {

		if (node->head[i-1].freq > arg[FREQ_OFFSET]) {

			node->head[i].freq = node->head[i-1].freq;

			node->head[i].power = node->head[i-1].power;

		} else if (node->head[i-1].freq != 0) {

			break;

		}

	}

	node->head[i].freq = arg[FREQ_OFFSET];

	node->head[i].power = arg[POWER_OFFSET];

	node->len++;

	if (node->ptr)

		node->ptr->len = node->len;

}

static int split_ptable_args(char *line, uint64_t *arg)

{

	char *args;

	int i;

	int ret = 0;

	for (i = 0; line; i++) {

		args = strsep(&line, " ");

		ret = kstrtoull(args, 10, &arg[i]);

	}

	return ret;

}

static ssize_t msm_core_ptable_write(struct file *file,

		const char __user *ubuf, size_t len, loff_t *offp)

{

	char *kbuf;

	int ret;

	uint64_t arg[3];

	if (len == 0)

		return 0;

	kbuf = kzalloc(len + 1, GFP_KERNEL);

	if (!kbuf)

		return -ENOMEM;

	if (copy_from_user(kbuf, ubuf, len)) {

		ret = -EFAULT;

		goto done;

	}

	kbuf[len] = '\0';

	ret = split_ptable_args(kbuf, arg);

	if (!ret) {

		add_to_ptable(arg);

		ret = len;

	}

done:

	kfree(kbuf);

	return ret;

}

static void print_table(struct seq_file *m, struct cpu_pstate_pwr *c_n,

		int len)

{

	int i;

	seq_puts(m, "   Freq       Power\n");

	for (i = 0; i < len; i++)

		seq_printf(m, "  %d       %u\n", c_n[i].freq,

				c_n[i].power);

}

static int msm_core_ptable_read(struct seq_file *m, void *data)

{

	int cpu;

	struct core_debug *node;

	for_each_possible_cpu(cpu) {

		node = &per_cpu(c_dgfs, cpu);

		if (node->head) {

			seq_printf(m, "-----  CPU%d - %s - Debug -------\n",

			cpu, node->enabled == 1 ? "Enabled" : "Written");

			print_table(m, node->head, node->len);

		}

		if (node->driver_data) {

			seq_printf(m, "--- CPU%d - Live numbers at %ldC---\n",

			cpu, node->ptr->temp);

			print_table(m, node->driver_data, node->driver_len);

		}

	}

	return 0;

}

static ssize_t msm_core_enable_write(struct file *file,

		const char __user *ubuf, size_t len, loff_t *offp)

{

	char *kbuf;

	int ret;

	uint64_t arg[3];

	int cpu;

	if (len == 0)

		return 0;

	kbuf = kzalloc(len + 1, GFP_KERNEL);

	if (!kbuf)

		return -ENOMEM;

	if (copy_from_user(kbuf, ubuf, len)) {

		ret = -EFAULT;

		goto done;

	}

	kbuf[len] = '\0';

	ret = split_ptable_args(kbuf, arg);

	if (ret)

		goto done;

	cpu = arg[CPU_OFFSET];

	if (cpu_possible(cpu)) {

		struct core_debug *node = &per_cpu(c_dgfs, cpu);

		if (arg[FREQ_OFFSET]) {

			msm_core_data[cpu].ptable = node->head;

			msm_core_data[cpu].len = node->len;

		} else {

			msm_core_data[cpu].ptable = node->driver_data;

			msm_core_data[cpu].len = node->driver_len;

			node->len = 0;

		}

		node->enabled = arg[FREQ_OFFSET];

	}

	ret = len;

done:

	kfree(kbuf);

	return ret;

}

static const struct file_operations msm_core_enable_ops = {

	.write = msm_core_enable_write,

};

static int msm_core_dump_open(struct inode *inode, struct file *file)

{

	return single_open(file, msm_core_ptable_read, inode->i_private);

}

static const struct file_operations msm_core_ptable_ops = {

	.open = msm_core_dump_open,

	.read = seq_read,

	.write = msm_core_ptable_write,

	.llseek = seq_lseek,

	.release = single_release,

};

int msm_core_debug_init(void)

{

	struct dentry *dir;

	struct dentry *file;

	int i;

	msm_core_data = get_cpu_pwr_stats();

	if (!msm_core_data)

		goto fail;

	dir = debugfs_create_dir("msm_core", NULL);

	if (IS_ERR_OR_NULL(dir))

		return PTR_ERR(dir);

	file = debugfs_create_file("enable", S_IRWXUGO, dir, NULL,

			&msm_core_enable_ops);

	if (IS_ERR_OR_NULL(file))

		goto fail;

	file = debugfs_create_file("ptable", S_IRWXUGO, dir, NULL,

			&msm_core_ptable_ops);

	if (IS_ERR_OR_NULL(file))

		goto fail;

	help_msg.size = strlen(help_msg.data);

	file = debugfs_create_blob("help", S_IRUGO, dir, &help_msg);

	if (IS_ERR_OR_NULL(file))

		goto fail;

	for (i = 0; i < num_possible_cpus(); i++) {

		per_cpu(c_dgfs, i).ptr = &msm_core_data[i];

		per_cpu(c_dgfs, i).driver_data = msm_core_data[i].ptable;

		per_cpu(c_dgfs, i).driver_len = msm_core_data[i].len;

	}

	return 0;

fail:

	debugfs_remove(dir);

	return PTR_ERR(file);

}

late_initcall(msm_core_debug_init);