[linux-2.6-block.git] / drivers / cpufreq / armada-37xx-cpufreq.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * CPU frequency scaling support for Armada 37xx platform.
 *
 * Copyright (C) 2017 Marvell
 *
 * Gregory CLEMENT <gregory.clement@free-electrons.com>
 */

#include <linux/clk.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/pm_opp.h>
#include <linux/regmap.h>
#include <linux/slab.h>

#include "cpufreq-dt.h"

/* Power management in North Bridge register set */
#define ARMADA_37XX_NB_L0L1	0x18
#define ARMADA_37XX_NB_L2L3	0x1C
#define  ARMADA_37XX_NB_TBG_DIV_OFF	13
#define  ARMADA_37XX_NB_TBG_DIV_MASK	0x7
#define  ARMADA_37XX_NB_CLK_SEL_OFF	11
#define  ARMADA_37XX_NB_CLK_SEL_MASK	0x1
#define  ARMADA_37XX_NB_CLK_SEL_TBG	0x1
#define  ARMADA_37XX_NB_TBG_SEL_OFF	9
#define  ARMADA_37XX_NB_TBG_SEL_MASK	0x3
#define  ARMADA_37XX_NB_VDD_SEL_OFF	6
#define  ARMADA_37XX_NB_VDD_SEL_MASK	0x3
#define  ARMADA_37XX_NB_CONFIG_SHIFT	16
#define ARMADA_37XX_NB_DYN_MOD	0x24
#define  ARMADA_37XX_NB_CLK_SEL_EN	BIT(26)
#define  ARMADA_37XX_NB_TBG_EN		BIT(28)
#define  ARMADA_37XX_NB_DIV_EN		BIT(29)
#define  ARMADA_37XX_NB_VDD_EN		BIT(30)
#define  ARMADA_37XX_NB_DFS_EN		BIT(31)
#define ARMADA_37XX_NB_CPU_LOAD 0x30
#define  ARMADA_37XX_NB_CPU_LOAD_MASK	0x3
#define  ARMADA_37XX_DVFS_LOAD_0	0
#define  ARMADA_37XX_DVFS_LOAD_1	1
#define  ARMADA_37XX_DVFS_LOAD_2	2
#define  ARMADA_37XX_DVFS_LOAD_3	3

/* AVS register set */
#define ARMADA_37XX_AVS_CTL0		0x0
#define	 ARMADA_37XX_AVS_ENABLE		BIT(30)
#define	 ARMADA_37XX_AVS_HIGH_VDD_LIMIT	16
#define	 ARMADA_37XX_AVS_LOW_VDD_LIMIT	22
#define	 ARMADA_37XX_AVS_VDD_MASK	0x3F
#define ARMADA_37XX_AVS_CTL2		0x8
#define	 ARMADA_37XX_AVS_LOW_VDD_EN	BIT(6)
#define ARMADA_37XX_AVS_VSET(x)	    (0x1C + 4 * (x))

/*
 * On Armada 37xx the Power management manages 4 level of CPU load,
 * each level can be associated with a CPU clock source, a CPU
 * divider, a VDD level, etc...
 */
#define LOAD_LEVEL_NR	4

#define MIN_VOLT_MV 1000

/*  AVS value for the corresponding voltage (in mV) */
static int avs_map[] = {
	747, 758, 770, 782, 793, 805, 817, 828, 840, 852, 863, 875, 887, 898,
	910, 922, 933, 945, 957, 968, 980, 992, 1003, 1015, 1027, 1038, 1050,
	1062, 1073, 1085, 1097, 1108, 1120, 1132, 1143, 1155, 1167, 1178, 1190,
	1202, 1213, 1225, 1237, 1248, 1260, 1272, 1283, 1295, 1307, 1318, 1330,
	1342
};

struct armada37xx_cpufreq_state {
	struct regmap *regmap;
	u32 nb_l0l1;
	u32 nb_l2l3;
	u32 nb_dyn_mod;
	u32 nb_cpu_load;
};

static struct armada37xx_cpufreq_state *armada37xx_cpufreq_state;

struct armada_37xx_dvfs {
	u32 cpu_freq_max;
	u8 divider[LOAD_LEVEL_NR];
	u32 avs[LOAD_LEVEL_NR];
};

static struct armada_37xx_dvfs armada_37xx_dvfs[] = {
	{.cpu_freq_max = 1200*1000*1000, .divider = {1, 2, 4, 6} },
	{.cpu_freq_max = 1000*1000*1000, .divider = {1, 2, 4, 5} },
	{.cpu_freq_max = 800*1000*1000,  .divider = {1, 2, 3, 4} },
	{.cpu_freq_max = 600*1000*1000,  .divider = {2, 4, 5, 6} },
};

static struct armada_37xx_dvfs *armada_37xx_cpu_freq_info_get(u32 freq)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(armada_37xx_dvfs); i++) {
		if (freq == armada_37xx_dvfs[i].cpu_freq_max)
			return &armada_37xx_dvfs[i];
	}

	pr_err("Unsupported CPU frequency %d MHz\n", freq/1000000);
	return NULL;
}

/*
 * Setup the four level managed by the hardware. Once the four level
 * will be configured then the DVFS will be enabled.
 */
static void __init armada37xx_cpufreq_dvfs_setup(struct regmap *base,
						 struct clk *clk, u8 *divider)
{
	int load_lvl;
	struct clk *parent;

	for (load_lvl = 0; load_lvl < LOAD_LEVEL_NR; load_lvl++) {
		unsigned int reg, mask, val, offset = 0;

		if (load_lvl <= ARMADA_37XX_DVFS_LOAD_1)
			reg = ARMADA_37XX_NB_L0L1;
		else
			reg = ARMADA_37XX_NB_L2L3;

		if (load_lvl == ARMADA_37XX_DVFS_LOAD_0 ||
		    load_lvl == ARMADA_37XX_DVFS_LOAD_2)
			offset += ARMADA_37XX_NB_CONFIG_SHIFT;

		/* Set cpu clock source, for all the level we use TBG */
		val = ARMADA_37XX_NB_CLK_SEL_TBG << ARMADA_37XX_NB_CLK_SEL_OFF;
		mask = (ARMADA_37XX_NB_CLK_SEL_MASK
			<< ARMADA_37XX_NB_CLK_SEL_OFF);

		/*
		 * Set cpu divider based on the pre-computed array in
		 * order to have balanced step.
		 */
		val |= divider[load_lvl] << ARMADA_37XX_NB_TBG_DIV_OFF;
		mask |= (ARMADA_37XX_NB_TBG_DIV_MASK
			<< ARMADA_37XX_NB_TBG_DIV_OFF);

		/* Set VDD divider which is actually the load level. */
		val |= load_lvl << ARMADA_37XX_NB_VDD_SEL_OFF;
		mask |= (ARMADA_37XX_NB_VDD_SEL_MASK
			<< ARMADA_37XX_NB_VDD_SEL_OFF);

		val <<= offset;
		mask <<= offset;

		regmap_update_bits(base, reg, mask, val);
	}

	/*
	 * Set cpu clock source, for all the level we keep the same
	 * clock source that the one already configured. For this one
	 * we need to use the clock framework
	 */
	parent = clk_get_parent(clk);
	clk_set_parent(clk, parent);
}

/*
 * Find out the armada 37x supported AVS value whose voltage value is
 * the round-up closest to the target voltage value.
 */
static u32 armada_37xx_avs_val_match(int target_vm)
{
	u32 avs;

	/* Find out the round-up closest supported voltage value */
	for (avs = 0; avs < ARRAY_SIZE(avs_map); avs++)
		if (avs_map[avs] >= target_vm)
			break;

	/*
	 * If all supported voltages are smaller than target one,
	 * choose the largest supported voltage
	 */
	if (avs == ARRAY_SIZE(avs_map))
		avs = ARRAY_SIZE(avs_map) - 1;

	return avs;
}

/*
 * For Armada 37xx soc, L0(VSET0) VDD AVS value is set to SVC revision
 * value or a default value when SVC is not supported.
 * - L0 can be read out from the register of AVS_CTRL_0 and L0 voltage
 *   can be got from the mapping table of avs_map.
 * - L1 voltage should be about 100mv smaller than L0 voltage
 * - L2 & L3 voltage should be about 150mv smaller than L0 voltage.
 * This function calculates L1 & L2 & L3 AVS values dynamically based
 * on L0 voltage and fill all AVS values to the AVS value table.
 */
static void __init armada37xx_cpufreq_avs_configure(struct regmap *base,
						struct armada_37xx_dvfs *dvfs)
{
	unsigned int target_vm;
	int load_level = 0;
	u32 l0_vdd_min;

	if (base == NULL)
		return;

	/* Get L0 VDD min value */
	regmap_read(base, ARMADA_37XX_AVS_CTL0, &l0_vdd_min);
	l0_vdd_min = (l0_vdd_min >> ARMADA_37XX_AVS_LOW_VDD_LIMIT) &
		ARMADA_37XX_AVS_VDD_MASK;
	if (l0_vdd_min >= ARRAY_SIZE(avs_map))  {
		pr_err("L0 VDD MIN %d is not correct.\n", l0_vdd_min);
		return;
	}
	dvfs->avs[0] = l0_vdd_min;

	if (avs_map[l0_vdd_min] <= MIN_VOLT_MV) {
		/*
		 * If L0 voltage is smaller than 1000mv, then all VDD sets
		 * use L0 voltage;
		 */
		u32 avs_min = armada_37xx_avs_val_match(MIN_VOLT_MV);

		for (load_level = 1; load_level < LOAD_LEVEL_NR; load_level++)
			dvfs->avs[load_level] = avs_min;

		return;
	}

	/*
	 * L1 voltage is equal to L0 voltage - 100mv and it must be
	 * larger than 1000mv
	 */

	target_vm = avs_map[l0_vdd_min] - 100;
	target_vm = target_vm > MIN_VOLT_MV ? target_vm : MIN_VOLT_MV;
	dvfs->avs[1] = armada_37xx_avs_val_match(target_vm);

	/*
	 * L2 & L3 voltage is equal to L0 voltage - 150mv and it must
	 * be larger than 1000mv
	 */
	target_vm = avs_map[l0_vdd_min] - 150;
	target_vm = target_vm > MIN_VOLT_MV ? target_vm : MIN_VOLT_MV;
	dvfs->avs[2] = dvfs->avs[3] = armada_37xx_avs_val_match(target_vm);
}

static void __init armada37xx_cpufreq_avs_setup(struct regmap *base,
						struct armada_37xx_dvfs *dvfs)
{
	unsigned int avs_val = 0, freq;
	int load_level = 0;

	if (base == NULL)
		return;

	/* Disable AVS before the configuration */
	regmap_update_bits(base, ARMADA_37XX_AVS_CTL0,
			   ARMADA_37XX_AVS_ENABLE, 0);


	/* Enable low voltage mode */
	regmap_update_bits(base, ARMADA_37XX_AVS_CTL2,
			   ARMADA_37XX_AVS_LOW_VDD_EN,
			   ARMADA_37XX_AVS_LOW_VDD_EN);


	for (load_level = 1; load_level < LOAD_LEVEL_NR; load_level++) {
		freq = dvfs->cpu_freq_max / dvfs->divider[load_level];

		avs_val = dvfs->avs[load_level];
		regmap_update_bits(base, ARMADA_37XX_AVS_VSET(load_level-1),
		    ARMADA_37XX_AVS_VDD_MASK << ARMADA_37XX_AVS_HIGH_VDD_LIMIT |
		    ARMADA_37XX_AVS_VDD_MASK << ARMADA_37XX_AVS_LOW_VDD_LIMIT,
		    avs_val << ARMADA_37XX_AVS_HIGH_VDD_LIMIT |
		    avs_val << ARMADA_37XX_AVS_LOW_VDD_LIMIT);
	}

	/* Enable AVS after the configuration */
	regmap_update_bits(base, ARMADA_37XX_AVS_CTL0,
			   ARMADA_37XX_AVS_ENABLE,
			   ARMADA_37XX_AVS_ENABLE);

}

static void armada37xx_cpufreq_disable_dvfs(struct regmap *base)
{
	unsigned int reg = ARMADA_37XX_NB_DYN_MOD,
		mask = ARMADA_37XX_NB_DFS_EN;

	regmap_update_bits(base, reg, mask, 0);
}

static void __init armada37xx_cpufreq_enable_dvfs(struct regmap *base)
{
	unsigned int val, reg = ARMADA_37XX_NB_CPU_LOAD,
		mask = ARMADA_37XX_NB_CPU_LOAD_MASK;

	/* Start with the highest load (0) */
	val = ARMADA_37XX_DVFS_LOAD_0;
	regmap_update_bits(base, reg, mask, val);

	/* Now enable DVFS for the CPUs */
	reg = ARMADA_37XX_NB_DYN_MOD;
	mask =	ARMADA_37XX_NB_CLK_SEL_EN | ARMADA_37XX_NB_TBG_EN |
		ARMADA_37XX_NB_DIV_EN | ARMADA_37XX_NB_VDD_EN |
		ARMADA_37XX_NB_DFS_EN;

	regmap_update_bits(base, reg, mask, mask);
}

static int armada37xx_cpufreq_suspend(struct cpufreq_policy *policy)
{
	struct armada37xx_cpufreq_state *state = armada37xx_cpufreq_state;

	regmap_read(state->regmap, ARMADA_37XX_NB_L0L1, &state->nb_l0l1);
	regmap_read(state->regmap, ARMADA_37XX_NB_L2L3, &state->nb_l2l3);
	regmap_read(state->regmap, ARMADA_37XX_NB_CPU_LOAD,
		    &state->nb_cpu_load);
	regmap_read(state->regmap, ARMADA_37XX_NB_DYN_MOD, &state->nb_dyn_mod);

	return 0;
}

static int armada37xx_cpufreq_resume(struct cpufreq_policy *policy)
{
	struct armada37xx_cpufreq_state *state = armada37xx_cpufreq_state;

	/* Ensure DVFS is disabled otherwise the following registers are RO */
	armada37xx_cpufreq_disable_dvfs(state->regmap);

	regmap_write(state->regmap, ARMADA_37XX_NB_L0L1, state->nb_l0l1);
	regmap_write(state->regmap, ARMADA_37XX_NB_L2L3, state->nb_l2l3);
	regmap_write(state->regmap, ARMADA_37XX_NB_CPU_LOAD,
		     state->nb_cpu_load);

	/*
	 * NB_DYN_MOD register is the one that actually enable back DVFS if it
	 * was enabled before the suspend operation. This must be done last
	 * otherwise other registers are not writable.
	 */
	regmap_write(state->regmap, ARMADA_37XX_NB_DYN_MOD, state->nb_dyn_mod);

	return 0;
}

static int __init armada37xx_cpufreq_driver_init(void)
{
	struct cpufreq_dt_platform_data pdata;
	struct armada_37xx_dvfs *dvfs;
	struct platform_device *pdev;
	unsigned long freq;
	unsigned int cur_frequency;
	struct regmap *nb_pm_base, *avs_base;
	struct device *cpu_dev;
	int load_lvl, ret;
	struct clk *clk;

	nb_pm_base =
		syscon_regmap_lookup_by_compatible("marvell,armada-3700-nb-pm");

	if (IS_ERR(nb_pm_base))
		return -ENODEV;

	avs_base =
		syscon_regmap_lookup_by_compatible("marvell,armada-3700-avs");

	/* if AVS is not present don't use it but still try to setup dvfs */
	if (IS_ERR(avs_base)) {
		pr_info("Syscon failed for Adapting Voltage Scaling: skip it\n");
		avs_base = NULL;
	}
	/* Before doing any configuration on the DVFS first, disable it */
	armada37xx_cpufreq_disable_dvfs(nb_pm_base);

	/*
	 * On CPU 0 register the operating points supported (which are
	 * the nominal CPU frequency and full integer divisions of
	 * it).
	 */
	cpu_dev = get_cpu_device(0);
	if (!cpu_dev) {
		dev_err(cpu_dev, "Cannot get CPU\n");
		return -ENODEV;
	}

	clk = clk_get(cpu_dev, 0);
	if (IS_ERR(clk)) {
		dev_err(cpu_dev, "Cannot get clock for CPU0\n");
		return PTR_ERR(clk);
	}

	/* Get nominal (current) CPU frequency */
	cur_frequency = clk_get_rate(clk);
	if (!cur_frequency) {
		dev_err(cpu_dev, "Failed to get clock rate for CPU\n");
		clk_put(clk);
		return -EINVAL;
	}

	dvfs = armada_37xx_cpu_freq_info_get(cur_frequency);
	if (!dvfs) {
		clk_put(clk);
		return -EINVAL;
	}

	armada37xx_cpufreq_state = kmalloc(sizeof(*armada37xx_cpufreq_state),
					   GFP_KERNEL);
	if (!armada37xx_cpufreq_state) {
		clk_put(clk);
		return -ENOMEM;
	}

	armada37xx_cpufreq_state->regmap = nb_pm_base;

	armada37xx_cpufreq_avs_configure(avs_base, dvfs);
	armada37xx_cpufreq_avs_setup(avs_base, dvfs);

	armada37xx_cpufreq_dvfs_setup(nb_pm_base, clk, dvfs->divider);
	clk_put(clk);

	for (load_lvl = ARMADA_37XX_DVFS_LOAD_0; load_lvl < LOAD_LEVEL_NR;
	     load_lvl++) {
		unsigned long u_volt = avs_map[dvfs->avs[load_lvl]] * 1000;
		freq = cur_frequency / dvfs->divider[load_lvl];
		ret = dev_pm_opp_add(cpu_dev, freq, u_volt);
		if (ret)
			goto remove_opp;


	}

	/* Now that everything is setup, enable the DVFS at hardware level */
	armada37xx_cpufreq_enable_dvfs(nb_pm_base);

	pdata.suspend = armada37xx_cpufreq_suspend;
	pdata.resume = armada37xx_cpufreq_resume;

	pdev = platform_device_register_data(NULL, "cpufreq-dt", -1, &pdata,
					     sizeof(pdata));
	ret = PTR_ERR_OR_ZERO(pdev);
	if (ret)
		goto disable_dvfs;

	return 0;

disable_dvfs:
	armada37xx_cpufreq_disable_dvfs(nb_pm_base);
remove_opp:
	/* clean-up the already added opp before leaving */
	while (load_lvl-- > ARMADA_37XX_DVFS_LOAD_0) {
		freq = cur_frequency / dvfs->divider[load_lvl];
		dev_pm_opp_remove(cpu_dev, freq);
	}

	kfree(armada37xx_cpufreq_state);

	return ret;
}
/* late_initcall, to guarantee the driver is loaded after A37xx clock driver */
late_initcall(armada37xx_cpufreq_driver_init);

MODULE_AUTHOR("Gregory CLEMENT <gregory.clement@free-electrons.com>");
MODULE_DESCRIPTION("Armada 37xx cpufreq driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
92ce45fb GC	1	// SPDX-License-Identifier: GPL-2.0+
	2	/*
	3	* CPU frequency scaling support for Armada 37xx platform.
	4	*
	5	* Copyright (C) 2017 Marvell
	6	*
	7	* Gregory CLEMENT <gregory.clement@free-electrons.com>
	8	*/
	9
	10	#include <linux/clk.h>
	11	#include <linux/cpu.h>
	12	#include <linux/cpufreq.h>
	13	#include <linux/err.h>
	14	#include <linux/interrupt.h>
	15	#include <linux/io.h>
	16	#include <linux/mfd/syscon.h>
	17	#include <linux/module.h>
	18	#include <linux/of_address.h>
	19	#include <linux/of_device.h>
	20	#include <linux/of_irq.h>
	21	#include <linux/platform_device.h>
	22	#include <linux/pm_opp.h>
	23	#include <linux/regmap.h>
	24	#include <linux/slab.h>
	25
9c28d6df MR	26	#include "cpufreq-dt.h"
9c28d6df MR	27
92ce45fb GC	28	/* Power management in North Bridge register set */
	29	#define ARMADA_37XX_NB_L0L1 0x18
	30	#define ARMADA_37XX_NB_L2L3 0x1C
	31	#define ARMADA_37XX_NB_TBG_DIV_OFF 13
	32	#define ARMADA_37XX_NB_TBG_DIV_MASK 0x7
	33	#define ARMADA_37XX_NB_CLK_SEL_OFF 11
	34	#define ARMADA_37XX_NB_CLK_SEL_MASK 0x1
	35	#define ARMADA_37XX_NB_CLK_SEL_TBG 0x1
	36	#define ARMADA_37XX_NB_TBG_SEL_OFF 9
	37	#define ARMADA_37XX_NB_TBG_SEL_MASK 0x3
	38	#define ARMADA_37XX_NB_VDD_SEL_OFF 6
	39	#define ARMADA_37XX_NB_VDD_SEL_MASK 0x3
	40	#define ARMADA_37XX_NB_CONFIG_SHIFT 16
	41	#define ARMADA_37XX_NB_DYN_MOD 0x24
	42	#define ARMADA_37XX_NB_CLK_SEL_EN BIT(26)
	43	#define ARMADA_37XX_NB_TBG_EN BIT(28)
	44	#define ARMADA_37XX_NB_DIV_EN BIT(29)
	45	#define ARMADA_37XX_NB_VDD_EN BIT(30)
	46	#define ARMADA_37XX_NB_DFS_EN BIT(31)
	47	#define ARMADA_37XX_NB_CPU_LOAD 0x30
	48	#define ARMADA_37XX_NB_CPU_LOAD_MASK 0x3
	49	#define ARMADA_37XX_DVFS_LOAD_0 0
	50	#define ARMADA_37XX_DVFS_LOAD_1 1
	51	#define ARMADA_37XX_DVFS_LOAD_2 2
	52	#define ARMADA_37XX_DVFS_LOAD_3 3
	53
1c352823 GC	54	/* AVS register set */
	55	#define ARMADA_37XX_AVS_CTL0 0x0
	56	#define ARMADA_37XX_AVS_ENABLE BIT(30)
	57	#define ARMADA_37XX_AVS_HIGH_VDD_LIMIT 16
	58	#define ARMADA_37XX_AVS_LOW_VDD_LIMIT 22
	59	#define ARMADA_37XX_AVS_VDD_MASK 0x3F
	60	#define ARMADA_37XX_AVS_CTL2 0x8
	61	#define ARMADA_37XX_AVS_LOW_VDD_EN BIT(6)
	62	#define ARMADA_37XX_AVS_VSET(x) (0x1C + 4 * (x))
	63
92ce45fb GC	64	/*
	65	* On Armada 37xx the Power management manages 4 level of CPU load,
	66	* each level can be associated with a CPU clock source, a CPU
	67	* divider, a VDD level, etc...
	68	*/
	69	#define LOAD_LEVEL_NR 4
	70
1c352823 GC	71	#define MIN_VOLT_MV 1000
	72
	73	/* AVS value for the corresponding voltage (in mV) */
	74	static int avs_map[] = {
	75	747, 758, 770, 782, 793, 805, 817, 828, 840, 852, 863, 875, 887, 898,
	76	910, 922, 933, 945, 957, 968, 980, 992, 1003, 1015, 1027, 1038, 1050,
	77	1062, 1073, 1085, 1097, 1108, 1120, 1132, 1143, 1155, 1167, 1178, 1190,
	78	1202, 1213, 1225, 1237, 1248, 1260, 1272, 1283, 1295, 1307, 1318, 1330,
	79	1342
	80	};
	81
9c28d6df MR	82	struct armada37xx_cpufreq_state {
	83	struct regmap *regmap;
	84	u32 nb_l0l1;
	85	u32 nb_l2l3;
	86	u32 nb_dyn_mod;
	87	u32 nb_cpu_load;
	88	};
	89
	90	static struct armada37xx_cpufreq_state *armada37xx_cpufreq_state;
	91
92ce45fb GC	92	struct armada_37xx_dvfs {
	93	u32 cpu_freq_max;
	94	u8 divider[LOAD_LEVEL_NR];
1c352823	95	u32 avs[LOAD_LEVEL_NR];
92ce45fb GC	96	};
	97
	98	static struct armada_37xx_dvfs armada_37xx_dvfs[] = {
	99	{.cpu_freq_max = 120010001000, .divider = {1, 2, 4, 6} },
	100	{.cpu_freq_max = 100010001000, .divider = {1, 2, 4, 5} },
	101	{.cpu_freq_max = 80010001000, .divider = {1, 2, 3, 4} },
	102	{.cpu_freq_max = 60010001000, .divider = {2, 4, 5, 6} },
	103	};
	104
	105	static struct armada_37xx_dvfs *armada_37xx_cpu_freq_info_get(u32 freq)
	106	{
	107	int i;
	108
	109	for (i = 0; i < ARRAY_SIZE(armada_37xx_dvfs); i++) {
	110	if (freq == armada_37xx_dvfs[i].cpu_freq_max)
	111	return &armada_37xx_dvfs[i];
	112	}
	113
	114	pr_err("Unsupported CPU frequency %d MHz\n", freq/1000000);
	115	return NULL;
	116	}
	117
	118	/*
	119	* Setup the four level managed by the hardware. Once the four level
	120	* will be configured then the DVFS will be enabled.
	121	*/
	122	static void __init armada37xx_cpufreq_dvfs_setup(struct regmap *base,
	123	struct clk clk, u8 divider)
	124	{
	125	int load_lvl;
	126	struct clk *parent;
	127
	128	for (load_lvl = 0; load_lvl < LOAD_LEVEL_NR; load_lvl++) {
	129	unsigned int reg, mask, val, offset = 0;
	130
	131	if (load_lvl <= ARMADA_37XX_DVFS_LOAD_1)
	132	reg = ARMADA_37XX_NB_L0L1;
	133	else
	134	reg = ARMADA_37XX_NB_L2L3;
	135
	136	if (load_lvl == ARMADA_37XX_DVFS_LOAD_0 \|\|
	137	load_lvl == ARMADA_37XX_DVFS_LOAD_2)
	138	offset += ARMADA_37XX_NB_CONFIG_SHIFT;
	139
	140	/* Set cpu clock source, for all the level we use TBG */
	141	val = ARMADA_37XX_NB_CLK_SEL_TBG << ARMADA_37XX_NB_CLK_SEL_OFF;
	142	mask = (ARMADA_37XX_NB_CLK_SEL_MASK
	143	<< ARMADA_37XX_NB_CLK_SEL_OFF);
	144
	145	/*
	146	* Set cpu divider based on the pre-computed array in
	147	* order to have balanced step.
	148	*/
	149	val \|= divider[load_lvl] << ARMADA_37XX_NB_TBG_DIV_OFF;
	150	mask \|= (ARMADA_37XX_NB_TBG_DIV_MASK
	151	<< ARMADA_37XX_NB_TBG_DIV_OFF);
	152
	153	/* Set VDD divider which is actually the load level. */
	154	val \|= load_lvl << ARMADA_37XX_NB_VDD_SEL_OFF;
	155	mask \|= (ARMADA_37XX_NB_VDD_SEL_MASK
	156	<< ARMADA_37XX_NB_VDD_SEL_OFF);
	157
	158	val <<= offset;
	159	mask <<= offset;
160
161	regmap_update_bits(base, reg, mask, val);
162	}
163
164	/*
165	* Set cpu clock source, for all the level we keep the same
166	* clock source that the one already configured. For this one
167	* we need to use the clock framework
168	*/
169	parent = clk_get_parent(clk);
170	clk_set_parent(clk, parent);
171	}
172
1c352823 GC	173	/*
	174	* Find out the armada 37x supported AVS value whose voltage value is
	175	* the round-up closest to the target voltage value.
	176	*/
	177	static u32 armada_37xx_avs_val_match(int target_vm)
	178	{
	179	u32 avs;
	180
	181	/* Find out the round-up closest supported voltage value */
	182	for (avs = 0; avs < ARRAY_SIZE(avs_map); avs++)
	183	if (avs_map[avs] >= target_vm)
	184	break;
	185
	186	/*
	187	* If all supported voltages are smaller than target one,
	188	* choose the largest supported voltage
	189	*/
	190	if (avs == ARRAY_SIZE(avs_map))
	191	avs = ARRAY_SIZE(avs_map) - 1;
	192
	193	return avs;
	194	}
	195
	196	/*
	197	* For Armada 37xx soc, L0(VSET0) VDD AVS value is set to SVC revision
	198	* value or a default value when SVC is not supported.
	199	* - L0 can be read out from the register of AVS_CTRL_0 and L0 voltage
	200	* can be got from the mapping table of avs_map.
	201	* - L1 voltage should be about 100mv smaller than L0 voltage
	202	* - L2 & L3 voltage should be about 150mv smaller than L0 voltage.
	203	* This function calculates L1 & L2 & L3 AVS values dynamically based
	204	* on L0 voltage and fill all AVS values to the AVS value table.
	205	*/
	206	static void __init armada37xx_cpufreq_avs_configure(struct regmap *base,
	207	struct armada_37xx_dvfs *dvfs)
	208	{
	209	unsigned int target_vm;
	210	int load_level = 0;
	211	u32 l0_vdd_min;
	212
	213	if (base == NULL)
	214	return;
	215
	216	/* Get L0 VDD min value */
	217	regmap_read(base, ARMADA_37XX_AVS_CTL0, &l0_vdd_min);
	218	l0_vdd_min = (l0_vdd_min >> ARMADA_37XX_AVS_LOW_VDD_LIMIT) &
	219	ARMADA_37XX_AVS_VDD_MASK;
	220	if (l0_vdd_min >= ARRAY_SIZE(avs_map)) {
	221	pr_err("L0 VDD MIN %d is not correct.\n", l0_vdd_min);
	222	return;
	223	}
	224	dvfs->avs[0] = l0_vdd_min;
	225
	226	if (avs_map[l0_vdd_min] <= MIN_VOLT_MV) {
	227	/*
	228	* If L0 voltage is smaller than 1000mv, then all VDD sets
	229	* use L0 voltage;
	230	*/
	231	u32 avs_min = armada_37xx_avs_val_match(MIN_VOLT_MV);
	232
	233	for (load_level = 1; load_level < LOAD_LEVEL_NR; load_level++)
	234	dvfs->avs[load_level] = avs_min;
	235
	236	return;
237	}
238
239	/*
240	* L1 voltage is equal to L0 voltage - 100mv and it must be
241	* larger than 1000mv
242	*/
243
244	target_vm = avs_map[l0_vdd_min] - 100;
245	target_vm = target_vm > MIN_VOLT_MV ? target_vm : MIN_VOLT_MV;
246	dvfs->avs[1] = armada_37xx_avs_val_match(target_vm);
247
248	/*
249	* L2 & L3 voltage is equal to L0 voltage - 150mv and it must
250	* be larger than 1000mv
251	*/
252	target_vm = avs_map[l0_vdd_min] - 150;
253	target_vm = target_vm > MIN_VOLT_MV ? target_vm : MIN_VOLT_MV;
254	dvfs->avs[2] = dvfs->avs[3] = armada_37xx_avs_val_match(target_vm);
255	}
256
257	static void __init armada37xx_cpufreq_avs_setup(struct regmap *base,
258	struct armada_37xx_dvfs *dvfs)
259	{
260	unsigned int avs_val = 0, freq;
261	int load_level = 0;
262
263	if (base == NULL)
264	return;
265
266	/* Disable AVS before the configuration */
267	regmap_update_bits(base, ARMADA_37XX_AVS_CTL0,
268	ARMADA_37XX_AVS_ENABLE, 0);
269
270
271	/* Enable low voltage mode */
272	regmap_update_bits(base, ARMADA_37XX_AVS_CTL2,
273	ARMADA_37XX_AVS_LOW_VDD_EN,
274	ARMADA_37XX_AVS_LOW_VDD_EN);
275
276
277	for (load_level = 1; load_level < LOAD_LEVEL_NR; load_level++) {
278	freq = dvfs->cpu_freq_max / dvfs->divider[load_level];
279
280	avs_val = dvfs->avs[load_level];
281	regmap_update_bits(base, ARMADA_37XX_AVS_VSET(load_level-1),
282	ARMADA_37XX_AVS_VDD_MASK << ARMADA_37XX_AVS_HIGH_VDD_LIMIT \|
283	ARMADA_37XX_AVS_VDD_MASK << ARMADA_37XX_AVS_LOW_VDD_LIMIT,
284	avs_val << ARMADA_37XX_AVS_HIGH_VDD_LIMIT \|
285	avs_val << ARMADA_37XX_AVS_LOW_VDD_LIMIT);
286	}
287
288	/* Enable AVS after the configuration */
289	regmap_update_bits(base, ARMADA_37XX_AVS_CTL0,
290	ARMADA_37XX_AVS_ENABLE,
291	ARMADA_37XX_AVS_ENABLE);
292
293	}
294
9c28d6df	295	static void armada37xx_cpufreq_disable_dvfs(struct regmap *base)
92ce45fb GC	296	{
	297	unsigned int reg = ARMADA_37XX_NB_DYN_MOD,
	298	mask = ARMADA_37XX_NB_DFS_EN;
	299
	300	regmap_update_bits(base, reg, mask, 0);
	301	}
	302
	303	static void __init armada37xx_cpufreq_enable_dvfs(struct regmap *base)
	304	{
	305	unsigned int val, reg = ARMADA_37XX_NB_CPU_LOAD,
	306	mask = ARMADA_37XX_NB_CPU_LOAD_MASK;
	307
	308	/* Start with the highest load (0) */
	309	val = ARMADA_37XX_DVFS_LOAD_0;
	310	regmap_update_bits(base, reg, mask, val);
	311
	312	/* Now enable DVFS for the CPUs */
	313	reg = ARMADA_37XX_NB_DYN_MOD;
	314	mask = ARMADA_37XX_NB_CLK_SEL_EN \| ARMADA_37XX_NB_TBG_EN \|
	315	ARMADA_37XX_NB_DIV_EN \| ARMADA_37XX_NB_VDD_EN \|
	316	ARMADA_37XX_NB_DFS_EN;
	317
	318	regmap_update_bits(base, reg, mask, mask);
	319	}
	320
9c28d6df MR	321	static int armada37xx_cpufreq_suspend(struct cpufreq_policy *policy)
	322	{
	323	struct armada37xx_cpufreq_state *state = armada37xx_cpufreq_state;
	324
	325	regmap_read(state->regmap, ARMADA_37XX_NB_L0L1, &state->nb_l0l1);
	326	regmap_read(state->regmap, ARMADA_37XX_NB_L2L3, &state->nb_l2l3);
	327	regmap_read(state->regmap, ARMADA_37XX_NB_CPU_LOAD,
	328	&state->nb_cpu_load);
	329	regmap_read(state->regmap, ARMADA_37XX_NB_DYN_MOD, &state->nb_dyn_mod);
	330
	331	return 0;
	332	}
	333
	334	static int armada37xx_cpufreq_resume(struct cpufreq_policy *policy)
	335	{
	336	struct armada37xx_cpufreq_state *state = armada37xx_cpufreq_state;
	337
	338	/* Ensure DVFS is disabled otherwise the following registers are RO */
	339	armada37xx_cpufreq_disable_dvfs(state->regmap);
	340
	341	regmap_write(state->regmap, ARMADA_37XX_NB_L0L1, state->nb_l0l1);
	342	regmap_write(state->regmap, ARMADA_37XX_NB_L2L3, state->nb_l2l3);
	343	regmap_write(state->regmap, ARMADA_37XX_NB_CPU_LOAD,
	344	state->nb_cpu_load);
	345
	346	/*
	347	* NB_DYN_MOD register is the one that actually enable back DVFS if it
	348	* was enabled before the suspend operation. This must be done last
	349	* otherwise other registers are not writable.
	350	*/
	351	regmap_write(state->regmap, ARMADA_37XX_NB_DYN_MOD, state->nb_dyn_mod);
	352
	353	return 0;
	354	}
	355
92ce45fb GC	356	static int __init armada37xx_cpufreq_driver_init(void)
92ce45fb GC	357	{
9c28d6df	358	struct cpufreq_dt_platform_data pdata;
92ce45fb GC	359	struct armada_37xx_dvfs *dvfs;
92ce45fb GC	360	struct platform_device *pdev;
cfd84631	361	unsigned long freq;
92ce45fb	362	unsigned int cur_frequency;
1c352823	363	struct regmap nb_pm_base, avs_base;
92ce45fb GC	364	struct device *cpu_dev;
	365	int load_lvl, ret;
	366	struct clk *clk;
	367
	368	nb_pm_base =
	369	syscon_regmap_lookup_by_compatible("marvell,armada-3700-nb-pm");
	370
	371	if (IS_ERR(nb_pm_base))
	372	return -ENODEV;
	373
1c352823 GC	374	avs_base =
	375	syscon_regmap_lookup_by_compatible("marvell,armada-3700-avs");
	376
	377	/* if AVS is not present don't use it but still try to setup dvfs */
	378	if (IS_ERR(avs_base)) {
	379	pr_info("Syscon failed for Adapting Voltage Scaling: skip it\n");
	380	avs_base = NULL;
	381	}
92ce45fb GC	382	/* Before doing any configuration on the DVFS first, disable it */
	383	armada37xx_cpufreq_disable_dvfs(nb_pm_base);
	384
	385	/*
	386	* On CPU 0 register the operating points supported (which are
	387	* the nominal CPU frequency and full integer divisions of
	388	* it).
	389	*/
	390	cpu_dev = get_cpu_device(0);
	391	if (!cpu_dev) {
	392	dev_err(cpu_dev, "Cannot get CPU\n");
	393	return -ENODEV;
	394	}
	395
	396	clk = clk_get(cpu_dev, 0);
	397	if (IS_ERR(clk)) {
	398	dev_err(cpu_dev, "Cannot get clock for CPU0\n");
	399	return PTR_ERR(clk);
	400	}
	401
	402	/* Get nominal (current) CPU frequency */
	403	cur_frequency = clk_get_rate(clk);
	404	if (!cur_frequency) {
	405	dev_err(cpu_dev, "Failed to get clock rate for CPU\n");
bbcc3285	406	clk_put(clk);
92ce45fb GC	407	return -EINVAL;
	408	}
	409
	410	dvfs = armada_37xx_cpu_freq_info_get(cur_frequency);
cfd84631 VK	411	if (!dvfs) {
cfd84631 VK	412	clk_put(clk);
92ce45fb	413	return -EINVAL;
cfd84631	414	}
92ce45fb	415
9c28d6df MR	416	armada37xx_cpufreq_state = kmalloc(sizeof(*armada37xx_cpufreq_state),
	417	GFP_KERNEL);
	418	if (!armada37xx_cpufreq_state) {
	419	clk_put(clk);
	420	return -ENOMEM;
	421	}
	422
	423	armada37xx_cpufreq_state->regmap = nb_pm_base;
	424
1c352823 GC	425	armada37xx_cpufreq_avs_configure(avs_base, dvfs);
	426	armada37xx_cpufreq_avs_setup(avs_base, dvfs);
	427
92ce45fb	428	armada37xx_cpufreq_dvfs_setup(nb_pm_base, clk, dvfs->divider);
bbcc3285	429	clk_put(clk);
92ce45fb GC	430
	431	for (load_lvl = ARMADA_37XX_DVFS_LOAD_0; load_lvl < LOAD_LEVEL_NR;
	432	load_lvl++) {
1c352823	433	unsigned long u_volt = avs_map[dvfs->avs[load_lvl]] * 1000;
cfd84631	434	freq = cur_frequency / dvfs->divider[load_lvl];
1c352823	435	ret = dev_pm_opp_add(cpu_dev, freq, u_volt);
cfd84631 VK	436	if (ret)
cfd84631 VK	437	goto remove_opp;
1c352823 GC	438
1c352823 GC	439
92ce45fb GC	440	}
	441
	442	/* Now that everything is setup, enable the DVFS at hardware level */
	443	armada37xx_cpufreq_enable_dvfs(nb_pm_base);
	444
9c28d6df MR	445	pdata.suspend = armada37xx_cpufreq_suspend;
	446	pdata.resume = armada37xx_cpufreq_resume;
	447
	448	pdev = platform_device_register_data(NULL, "cpufreq-dt", -1, &pdata,
	449	sizeof(pdata));
cfd84631 VK	450	ret = PTR_ERR_OR_ZERO(pdev);
	451	if (ret)
	452	goto disable_dvfs;
	453
	454	return 0;
	455
	456	disable_dvfs:
	457	armada37xx_cpufreq_disable_dvfs(nb_pm_base);
	458	remove_opp:
	459	/* clean-up the already added opp before leaving */
	460	while (load_lvl-- > ARMADA_37XX_DVFS_LOAD_0) {
	461	freq = cur_frequency / dvfs->divider[load_lvl];
	462	dev_pm_opp_remove(cpu_dev, freq);
	463	}
92ce45fb	464
9c28d6df MR	465	kfree(armada37xx_cpufreq_state);
9c28d6df MR	466
cfd84631	467	return ret;
92ce45fb GC	468	}
	469	/* late_initcall, to guarantee the driver is loaded after A37xx clock driver */
	470	late_initcall(armada37xx_cpufreq_driver_init);
	471
	472	MODULE_AUTHOR("Gregory CLEMENT <gregory.clement@free-electrons.com>");
	473	MODULE_DESCRIPTION("Armada 37xx cpufreq driver");
	474	MODULE_LICENSE("GPL");