/*
 * Copyright (c) 2013-2015, 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.
 */

#define pr_fmt(fmt) "%s: " fmt, __func__

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/cpu.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/of.h>
#include <linux/clk/msm-clock-generic.h>
#include <linux/of_platform.h>
#include <linux/pm_opp.h>
#include <soc/qcom/clock-local2.h>
#include <dt-bindings/clock/msm-clocks-a7.h>

#include "clock.h"

DEFINE_VDD_REGS_INIT(vdd_cpu, 1);

static struct mux_div_clk a7ssmux = {
	.ops = &rcg_mux_div_ops,
	.safe_freq = 300000000,
	.data = {
		.max_div = 32,
		.min_div = 2,
		.is_half_divider = true,
	},
	.c = {
		.dbg_name = "a7ssmux",
		.ops = &clk_ops_mux_div_clk,
		.vdd_class = &vdd_cpu,
		CLK_INIT(a7ssmux.c),
	},
	.parents = (struct clk_src[8]) {},
	.div_mask = BM(4, 0),
	.src_mask = BM(10, 8) >> 8,
	.src_shift = 8,
};

static struct clk_lookup clock_tbl_a7[] = {
	CLK_LIST(a7ssmux),
	CLK_LOOKUP_OF("cpu0_clk",	a7ssmux, "fe805664.qcom,pm"),
	CLK_LOOKUP_OF("cpu1_clk",	a7ssmux, "fe805664.qcom,pm"),
	CLK_LOOKUP_OF("cpu2_clk",	a7ssmux, "fe805664.qcom,pm"),
	CLK_LOOKUP_OF("cpu3_clk",	a7ssmux, "fe805664.qcom,pm"),
	CLK_LOOKUP_OF("cpu0_clk",   a7ssmux, "8600664.qcom,pm"),
	CLK_LOOKUP_OF("cpu1_clk",   a7ssmux, "8600664.qcom,pm"),
	CLK_LOOKUP_OF("cpu2_clk",   a7ssmux, "8600664.qcom,pm"),
	CLK_LOOKUP_OF("cpu3_clk",   a7ssmux, "8600664.qcom,pm"),
};

static void print_opp_table(int a7_cpu)
{
	struct dev_pm_opp *oppfmax, *oppfmin;
	unsigned long apc0_fmax = a7ssmux.c.fmax[a7ssmux.c.num_fmax - 1];
	unsigned long apc0_fmin = a7ssmux.c.fmax[1];

	rcu_read_lock();
	oppfmax = dev_pm_opp_find_freq_exact(get_cpu_device(a7_cpu), apc0_fmax,
						true);
	oppfmin = dev_pm_opp_find_freq_exact(get_cpu_device(a7_cpu), apc0_fmin,
						true);

	/* One time information during boot. */
	pr_info("clock_cpu: a7: OPP voltage for %lu: %ld\n", apc0_fmin,
			dev_pm_opp_get_voltage(oppfmin));
	pr_info("clock_cpu: a7: OPP voltage for %lu: %ld\n", apc0_fmax,
			dev_pm_opp_get_voltage(oppfmax));

	rcu_read_unlock();
}

static int add_opp(struct clk *c, struct device *cpudev, struct device *vregdev,
			unsigned long max_rate)
{
	unsigned long rate = 0;
	int level;
	long ret, uv, corner;

	while (1) {
		ret = clk_round_rate(c, rate + 1);
		if (ret < 0) {
			pr_warn("clock-cpu: round_rate failed at %lu\n", rate);
			return ret;
		}

		rate = ret;

		level = find_vdd_level(c, rate);
		if (level <= 0) {
			pr_warn("clock-cpu: no uv for %lu.\n", rate);
			return -EINVAL;
		}

		uv = corner = c->vdd_class->vdd_uv[level];

		/*
		 * Populate both CPU and regulator devices with the
		 * freq-to-corner OPP table to maintain backward
		 * compatibility.
		 */
		ret = dev_pm_opp_add(cpudev, rate, corner);
		if (ret) {
			pr_warn("clock-cpu: couldn't add OPP for %lu\n",
					rate);
			return ret;
		}

		ret = dev_pm_opp_add(vregdev, rate, corner);
		if (ret) {
			pr_warn("clock-cpu: couldn't add OPP for %lu\n",
					rate);
			return ret;
		}

		if (rate >= max_rate)
			break;
	}

	return 0;
}

static void populate_opp_table(struct platform_device *pdev)
{
	struct platform_device *apc_dev;
	struct device_node *apc_node;
	unsigned long apc_fmax;
	int cpu, a7_cpu = 0;

	apc_node = of_parse_phandle(pdev->dev.of_node, "cpu-vdd-supply", 0);
	if (!apc_node) {
		pr_err("can't find the apc0 dt node.\n");
		return;
	}

	apc_dev = of_find_device_by_node(apc_node);
	if (!apc_dev) {
		pr_err("can't find the apc0 device node.\n");
		return;
	}

	apc_fmax = a7ssmux.c.fmax[a7ssmux.c.num_fmax - 1];

	for_each_possible_cpu(cpu) {
		a7_cpu = cpu;
		WARN(add_opp(&a7ssmux.c, get_cpu_device(cpu),
					&apc_dev->dev, apc_fmax),
				"Failed to add OPP levels for A7\n");
	}

	/* One time print during bootup */
	pr_info("clock-a7: OPP tables populated (cpu %d)\n", a7_cpu);

	print_opp_table(a7_cpu);
}

static int of_get_fmax_vdd_class(struct platform_device *pdev, struct clk *c,
								char *prop_name)
{
	struct device_node *of = pdev->dev.of_node;
	int prop_len, i;
	struct clk_vdd_class *vdd = c->vdd_class;
	u32 *array;

	if (!of_find_property(of, prop_name, &prop_len)) {
		dev_err(&pdev->dev, "missing %s\n", prop_name);
		return -EINVAL;
	}

	prop_len /= sizeof(u32);
	if (prop_len % 2) {
		dev_err(&pdev->dev, "bad length %d\n", prop_len);
		return -EINVAL;
	}

	prop_len /= 2;
	vdd->level_votes = devm_kzalloc(&pdev->dev, prop_len * sizeof(int),
					GFP_KERNEL);
	if (!vdd->level_votes)
		return -ENOMEM;

	vdd->vdd_uv = devm_kzalloc(&pdev->dev, prop_len * sizeof(int),
					GFP_KERNEL);
	if (!vdd->vdd_uv)
		return -ENOMEM;

	c->fmax = devm_kzalloc(&pdev->dev, prop_len * sizeof(unsigned long),
					GFP_KERNEL);
	if (!c->fmax)
		return -ENOMEM;

	array = devm_kzalloc(&pdev->dev,
			prop_len * sizeof(u32) * 2, GFP_KERNEL);
	if (!array)
		return -ENOMEM;

	of_property_read_u32_array(of, prop_name, array, prop_len * 2);
	for (i = 0; i < prop_len; i++) {
		c->fmax[i] = array[2 * i];
		vdd->vdd_uv[i] = array[2 * i + 1];
	}

	devm_kfree(&pdev->dev, array);
	vdd->num_levels = prop_len;
	vdd->cur_level = prop_len;
	c->num_fmax = prop_len;
	return 0;
}

static void get_speed_bin(struct platform_device *pdev, int *bin, int *version)
{
	struct resource *res;
	void __iomem *base;
	u32 pte_efuse, redundant_sel, valid;

	*bin = 0;
	*version = 0;

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "efuse");
	if (!res) {
		dev_info(&pdev->dev,
			 "No speed/PVS binning available. Defaulting to 0!\n");
		return;
	}

	base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
	if (!base) {
		dev_warn(&pdev->dev,
			 "Unable to read efuse data. Defaulting to 0!\n");
		return;
	}

	pte_efuse = readl_relaxed(base);
	devm_iounmap(&pdev->dev, base);

	redundant_sel = (pte_efuse >> 24) & 0x7;
	*bin = pte_efuse & 0x7;
	valid = (pte_efuse >> 3) & 0x1;
	*version = (pte_efuse >> 4) & 0x3;

	if (redundant_sel == 1)
		*bin = (pte_efuse >> 27) & 0x7;

	if (!valid) {
		dev_info(&pdev->dev, "Speed bin not set. Defaulting to 0!\n");
		*bin = 0;
	} else {
		dev_info(&pdev->dev, "Speed bin: %d\n", *bin);
	}

	dev_info(&pdev->dev, "PVS version: %d\n", *version);

	return;
}

static void get_speed_bin_b(struct platform_device *pdev, int *bin,
								int *version)
{
	struct resource *res;
	void __iomem *base;
	u32 pte_efuse, shift = 2, mask = 0x7;

	*bin = 0;
	*version = 0;

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "efuse1");
	if (res) {
		base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
		if (base) {
			pte_efuse = readl_relaxed(base);
			devm_iounmap(&pdev->dev, base);

			*version = (pte_efuse >> 18) & 0x3;
			if (!(*version)) {
				*bin = (pte_efuse >> 23) & 0x3;
				if (*bin) {
					dev_info(&pdev->dev, "Speed bin: %d PVS Version: %d\n",
						*bin, *version);
					return;
				}
			}
		} else {
			dev_warn(&pdev->dev,
				"Unable to read efuse1 data. Defaulting to 0!\n");
			return;
		}
	}

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "efuse");
	if (!res) {
		dev_info(&pdev->dev,
				"No speed/PVS binning available. Defaulting to 0!\n");
		return;
	}
	base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
	if (!base) {
		dev_warn(&pdev->dev,
			 "Unable to read efuse data. Defaulting to 0!\n");
		return;
	}

	pte_efuse = readl_relaxed(base);
	devm_iounmap(&pdev->dev, base);

	*bin = (pte_efuse >> shift) & mask;

	dev_info(&pdev->dev, "Speed bin: %d PVS Version: %d\n", *bin,
								*version);
}

static int of_get_clk_src(struct platform_device *pdev, struct clk_src *parents)
{
	struct device_node *of = pdev->dev.of_node;
	int num_parents, i, j, index;
	struct clk *c;
	char clk_name[] = "clk-x";

	num_parents = of_property_count_strings(of, "clock-names");
	if (num_parents <= 0 || num_parents > 8) {
		dev_err(&pdev->dev, "missing clock-names\n");
		return -EINVAL;
	}

	j = 0;
	for (i = 0; i < 8; i++) {
		snprintf(clk_name, ARRAY_SIZE(clk_name), "clk-%d", i);
		index = of_property_match_string(of, "clock-names", clk_name);
		if (IS_ERR_VALUE(index))
			continue;

		parents[j].sel = i;
		parents[j].src = c = devm_clk_get(&pdev->dev, clk_name);
		if (IS_ERR(c)) {
			if (c != ERR_PTR(-EPROBE_DEFER))
				dev_err(&pdev->dev, "clk_get: %s\n fail",
						clk_name);
			return PTR_ERR(c);
		}
		j++;
	}

	return num_parents;
}

static struct platform_device *cpu_clock_a7_dev;

static int clock_a7_probe(struct platform_device *pdev)
{
	struct resource *res;
	int speed_bin = 0, version = 0, rc, cpu;
	unsigned long rate, aux_rate;
	struct clk *aux_clk, *main_pll;
	char prop_name[] = "qcom,speedX-bin-vX";
	const void *prop;
	bool compat_bin = false;
	bool compat_bin2 = false;
	bool opp_enable;

	compat_bin = of_device_is_compatible(pdev->dev.of_node,
						"qcom,clock-a53-8916");
	compat_bin2 = of_device_is_compatible(pdev->dev.of_node,
						"qcom,clock-a7-mdm9607");

	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rcg-base");
	if (!res) {
		dev_err(&pdev->dev, "missing rcg-base\n");
		return -EINVAL;
	}
	a7ssmux.base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
	if (!a7ssmux.base) {
		dev_err(&pdev->dev, "ioremap failed for rcg-base\n");
		return -ENOMEM;
	}

	vdd_cpu.regulator[0] = devm_regulator_get(&pdev->dev, "cpu-vdd");
	if (IS_ERR(vdd_cpu.regulator[0])) {
		if (PTR_ERR(vdd_cpu.regulator[0]) != -EPROBE_DEFER)
			dev_err(&pdev->dev, "unable to get regulator\n");
		return PTR_ERR(vdd_cpu.regulator[0]);
	}

	rc = of_get_clk_src(pdev, a7ssmux.parents);
	if (IS_ERR_VALUE(rc))
		return rc;

	a7ssmux.num_parents = rc;

	/* Override the existing safe operating frequency */
	prop = of_get_property(pdev->dev.of_node, "qcom,safe-freq", NULL);
	if (prop)
		a7ssmux.safe_freq = of_read_ulong(prop, 1);

	if (compat_bin || compat_bin2)
		get_speed_bin_b(pdev, &speed_bin, &version);
	else
		get_speed_bin(pdev, &speed_bin, &version);

	snprintf(prop_name, ARRAY_SIZE(prop_name),
			"qcom,speed%d-bin-v%d", speed_bin, version);
	rc = of_get_fmax_vdd_class(pdev, &a7ssmux.c, prop_name);
	if (rc) {
		/* Fall back to most conservative PVS table */
		dev_err(&pdev->dev, "Unable to load voltage plan %s!\n",
								prop_name);
		rc = of_get_fmax_vdd_class(pdev, &a7ssmux.c,
						"qcom,speed0-bin-v0");
		if (rc) {
			dev_err(&pdev->dev,
					"Unable to load safe voltage plan\n");
			return rc;
		}
		dev_info(&pdev->dev, "Safe voltage plan loaded.\n");
	}

	rc = of_msm_clock_register(pdev->dev.of_node,
			clock_tbl_a7, ARRAY_SIZE(clock_tbl_a7));
	if (rc) {
		dev_err(&pdev->dev, "msm_clock_register failed\n");
		return rc;
	}

	/* Force a PLL reconfiguration */
	aux_clk = a7ssmux.parents[0].src;
	main_pll = a7ssmux.parents[1].src;

	aux_rate = clk_get_rate(aux_clk);
	rate = clk_get_rate(&a7ssmux.c);
	clk_set_rate(&a7ssmux.c, aux_rate);
	clk_set_rate(main_pll, clk_round_rate(main_pll, 1));
	clk_set_rate(&a7ssmux.c, rate);

	/*
	 * We don't want the CPU clocks to be turned off at late init
	 * if CPUFREQ or HOTPLUG configs are disabled. So, bump up the
	 * refcount of these clocks. Any cpufreq/hotplug manager can assume
	 * that the clocks have already been prepared and enabled by the time
	 * they take over.
	 */
	get_online_cpus();
	for_each_online_cpu(cpu)
		WARN(clk_prepare_enable(&a7ssmux.c),
			"Unable to turn on CPU clock");
	put_online_cpus();

	opp_enable = of_property_read_bool(pdev->dev.of_node,
						"qcom,enable-opp");
	if (opp_enable)
		cpu_clock_a7_dev = pdev;

	return 0;
}

static struct of_device_id clock_a7_match_table[] = {
	{.compatible = "qcom,clock-a7-8226"},
	{.compatible = "qcom,clock-a7-krypton"},
	{.compatible = "qcom,clock-a7-9630"},
	{.compatible = "qcom,clock-a7-9640"},
	{.compatible = "qcom,clock-a53-8916"},
	{.compatible = "qcom,clock-a7-californium"},
	{.compatible = "qcom,clock-a7-mdm9607"},
	{}
};

static struct platform_driver clock_a7_driver = {
	.probe = clock_a7_probe,
	.driver = {
		.name = "clock-a7",
		.of_match_table = clock_a7_match_table,
		.owner = THIS_MODULE,
	},
};

static int __init clock_a7_init(void)
{
	return platform_driver_register(&clock_a7_driver);
}
arch_initcall(clock_a7_init);

/* CPU devices are not currently available in arch_initcall */
static int __init cpu_clock_a7_init_opp(void)
{
	if (cpu_clock_a7_dev)
		populate_opp_table(cpu_clock_a7_dev);
	return 0;
}
module_init(cpu_clock_a7_init_opp);