[linux-block.git] / drivers / cpufreq / tegra194-cpufreq.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2020, NVIDIA CORPORATION. All rights reserved
 */

#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#include <asm/smp_plat.h>

#include <soc/tegra/bpmp.h>
#include <soc/tegra/bpmp-abi.h>

#define KHZ                     1000
#define REF_CLK_MHZ             408 /* 408 MHz */
#define US_DELAY                500
#define CPUFREQ_TBL_STEP_HZ     (50 * KHZ * KHZ)
#define MAX_CNT                 ~0U

/* cpufreq transisition latency */
#define TEGRA_CPUFREQ_TRANSITION_LATENCY (300 * 1000) /* unit in nanoseconds */

enum cluster {
	CLUSTER0,
	CLUSTER1,
	CLUSTER2,
	CLUSTER3,
	MAX_CLUSTERS,
};

struct tegra194_cpufreq_data {
	void __iomem *regs;
	size_t num_clusters;
	struct cpufreq_frequency_table **tables;
};

struct tegra_cpu_ctr {
	u32 cpu;
	u32 coreclk_cnt, last_coreclk_cnt;
	u32 refclk_cnt, last_refclk_cnt;
};

struct read_counters_work {
	struct work_struct work;
	struct tegra_cpu_ctr c;
};

static struct workqueue_struct *read_counters_wq;

static void get_cpu_cluster(void *cluster)
{
	u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK;

	*((uint32_t *)cluster) = MPIDR_AFFINITY_LEVEL(mpidr, 1);
}

/*
 * Read per-core Read-only system register NVFREQ_FEEDBACK_EL1.
 * The register provides frequency feedback information to
 * determine the average actual frequency a core has run at over
 * a period of time.
 *	[31:0] PLLP counter: Counts at fixed frequency (408 MHz)
 *	[63:32] Core clock counter: counts on every core clock cycle
 *			where the core is architecturally clocking
 */
static u64 read_freq_feedback(void)
{
	u64 val = 0;

	asm volatile("mrs %0, s3_0_c15_c0_5" : "=r" (val) : );

	return val;
}

static inline u32 map_ndiv_to_freq(struct mrq_cpu_ndiv_limits_response
				   *nltbl, u16 ndiv)
{
	return nltbl->ref_clk_hz / KHZ * ndiv / (nltbl->pdiv * nltbl->mdiv);
}

static void tegra_read_counters(struct work_struct *work)
{
	struct read_counters_work *read_counters_work;
	struct tegra_cpu_ctr *c;
	u64 val;

	/*
	 * ref_clk_counter(32 bit counter) runs on constant clk,
	 * pll_p(408MHz).
	 * It will take = 2 ^ 32 / 408 MHz to overflow ref clk counter
	 *              = 10526880 usec = 10.527 sec to overflow
	 *
	 * Like wise core_clk_counter(32 bit counter) runs on core clock.
	 * It's synchronized to crab_clk (cpu_crab_clk) which runs at
	 * freq of cluster. Assuming max cluster clock ~2000MHz,
	 * It will take = 2 ^ 32 / 2000 MHz to overflow core clk counter
	 *              = ~2.147 sec to overflow
	 */
	read_counters_work = container_of(work, struct read_counters_work,
					  work);
	c = &read_counters_work->c;

	val = read_freq_feedback();
	c->last_refclk_cnt = lower_32_bits(val);
	c->last_coreclk_cnt = upper_32_bits(val);
	udelay(US_DELAY);
	val = read_freq_feedback();
	c->refclk_cnt = lower_32_bits(val);
	c->coreclk_cnt = upper_32_bits(val);
}

/*
 * Return instantaneous cpu speed
 * Instantaneous freq is calculated as -
 * -Takes sample on every query of getting the freq.
 *	- Read core and ref clock counters;
 *	- Delay for X us
 *	- Read above cycle counters again
 *	- Calculates freq by subtracting current and previous counters
 *	  divided by the delay time or eqv. of ref_clk_counter in delta time
 *	- Return Kcycles/second, freq in KHz
 *
 *	delta time period = x sec
 *			  = delta ref_clk_counter / (408 * 10^6) sec
 *	freq in Hz = cycles/sec
 *		   = (delta cycles / x sec
 *		   = (delta cycles * 408 * 10^6) / delta ref_clk_counter
 *	in KHz	   = (delta cycles * 408 * 10^3) / delta ref_clk_counter
 *
 * @cpu - logical cpu whose freq to be updated
 * Returns freq in KHz on success, 0 if cpu is offline
 */
static unsigned int tegra194_calculate_speed(u32 cpu)
{
	struct read_counters_work read_counters_work;
	struct tegra_cpu_ctr c;
	u32 delta_refcnt;
	u32 delta_ccnt;
	u32 rate_mhz;

	/*
	 * udelay() is required to reconstruct cpu frequency over an
	 * observation window. Using workqueue to call udelay() with
	 * interrupts enabled.
	 */
	read_counters_work.c.cpu = cpu;
	INIT_WORK_ONSTACK(&read_counters_work.work, tegra_read_counters);
	queue_work_on(cpu, read_counters_wq, &read_counters_work.work);
	flush_work(&read_counters_work.work);
	c = read_counters_work.c;

	if (c.coreclk_cnt < c.last_coreclk_cnt)
		delta_ccnt = c.coreclk_cnt + (MAX_CNT - c.last_coreclk_cnt);
	else
		delta_ccnt = c.coreclk_cnt - c.last_coreclk_cnt;
	if (!delta_ccnt)
		return 0;

	/* ref clock is 32 bits */
	if (c.refclk_cnt < c.last_refclk_cnt)
		delta_refcnt = c.refclk_cnt + (MAX_CNT - c.last_refclk_cnt);
	else
		delta_refcnt = c.refclk_cnt - c.last_refclk_cnt;
	if (!delta_refcnt) {
		pr_debug("cpufreq: %d is idle, delta_refcnt: 0\n", cpu);
		return 0;
	}
	rate_mhz = ((unsigned long)(delta_ccnt * REF_CLK_MHZ)) / delta_refcnt;

	return (rate_mhz * KHZ); /* in KHz */
}

static void get_cpu_ndiv(void *ndiv)
{
	u64 ndiv_val;

	asm volatile("mrs %0, s3_0_c15_c0_4" : "=r" (ndiv_val) : );

	*(u64 *)ndiv = ndiv_val;
}

static void set_cpu_ndiv(void *data)
{
	struct cpufreq_frequency_table *tbl = data;
	u64 ndiv_val = (u64)tbl->driver_data;

	asm volatile("msr s3_0_c15_c0_4, %0" : : "r" (ndiv_val));
}

static unsigned int tegra194_get_speed(u32 cpu)
{
	struct tegra194_cpufreq_data *data = cpufreq_get_driver_data();
	struct cpufreq_frequency_table *pos;
	unsigned int rate;
	u64 ndiv;
	int ret;
	u32 cl;

	smp_call_function_single(cpu, get_cpu_cluster, &cl, true);

	/* reconstruct actual cpu freq using counters */
	rate = tegra194_calculate_speed(cpu);

	/* get last written ndiv value */
	ret = smp_call_function_single(cpu, get_cpu_ndiv, &ndiv, true);
	if (WARN_ON_ONCE(ret))
		return rate;

	/*
	 * If the reconstructed frequency has acceptable delta from
	 * the last written value, then return freq corresponding
	 * to the last written ndiv value from freq_table. This is
	 * done to return consistent value.
	 */
	cpufreq_for_each_valid_entry(pos, data->tables[cl]) {
		if (pos->driver_data != ndiv)
			continue;

		if (abs(pos->frequency - rate) > 115200) {
			pr_warn("cpufreq: cpu%d,cur:%u,set:%u,set ndiv:%llu\n",
				cpu, rate, pos->frequency, ndiv);
		} else {
			rate = pos->frequency;
		}
		break;
	}
	return rate;
}

static int tegra194_cpufreq_init(struct cpufreq_policy *policy)
{
	struct tegra194_cpufreq_data *data = cpufreq_get_driver_data();
	u32 cpu;
	u32 cl;

	smp_call_function_single(policy->cpu, get_cpu_cluster, &cl, true);

	if (cl >= data->num_clusters || !data->tables[cl])
		return -EINVAL;

	/* set same policy for all cpus in a cluster */
	for (cpu = (cl * 2); cpu < ((cl + 1) * 2); cpu++)
		cpumask_set_cpu(cpu, policy->cpus);

	policy->freq_table = data->tables[cl];
	policy->cpuinfo.transition_latency = TEGRA_CPUFREQ_TRANSITION_LATENCY;

	return 0;
}

static int tegra194_cpufreq_set_target(struct cpufreq_policy *policy,
				       unsigned int index)
{
	struct cpufreq_frequency_table *tbl = policy->freq_table + index;

	/*
	 * Each core writes frequency in per core register. Then both cores
	 * in a cluster run at same frequency which is the maximum frequency
	 * request out of the values requested by both cores in that cluster.
	 */
	on_each_cpu_mask(policy->cpus, set_cpu_ndiv, tbl, true);

	return 0;
}

static struct cpufreq_driver tegra194_cpufreq_driver = {
	.name = "tegra194",
	.flags = CPUFREQ_CONST_LOOPS | CPUFREQ_NEED_INITIAL_FREQ_CHECK,
	.verify = cpufreq_generic_frequency_table_verify,
	.target_index = tegra194_cpufreq_set_target,
	.get = tegra194_get_speed,
	.init = tegra194_cpufreq_init,
	.attr = cpufreq_generic_attr,
};

static void tegra194_cpufreq_free_resources(void)
{
	destroy_workqueue(read_counters_wq);
}

static struct cpufreq_frequency_table *
init_freq_table(struct platform_device *pdev, struct tegra_bpmp *bpmp,
		unsigned int cluster_id)
{
	struct cpufreq_frequency_table *freq_table;
	struct mrq_cpu_ndiv_limits_response resp;
	unsigned int num_freqs, ndiv, delta_ndiv;
	struct mrq_cpu_ndiv_limits_request req;
	struct tegra_bpmp_message msg;
	u16 freq_table_step_size;
	int err, index;

	memset(&req, 0, sizeof(req));
	req.cluster_id = cluster_id;

	memset(&msg, 0, sizeof(msg));
	msg.mrq = MRQ_CPU_NDIV_LIMITS;
	msg.tx.data = &req;
	msg.tx.size = sizeof(req);
	msg.rx.data = &resp;
	msg.rx.size = sizeof(resp);

	err = tegra_bpmp_transfer(bpmp, &msg);
	if (err)
		return ERR_PTR(err);
	if (msg.rx.ret == -BPMP_EINVAL) {
		/* Cluster not available */
		return NULL;
	}
	if (msg.rx.ret)
		return ERR_PTR(-EINVAL);

	/*
	 * Make sure frequency table step is a multiple of mdiv to match
	 * vhint table granularity.
	 */
	freq_table_step_size = resp.mdiv *
			DIV_ROUND_UP(CPUFREQ_TBL_STEP_HZ, resp.ref_clk_hz);

	dev_dbg(&pdev->dev, "cluster %d: frequency table step size: %d\n",
		cluster_id, freq_table_step_size);

	delta_ndiv = resp.ndiv_max - resp.ndiv_min;

	if (unlikely(delta_ndiv == 0)) {
		num_freqs = 1;
	} else {
		/* We store both ndiv_min and ndiv_max hence the +1 */
		num_freqs = delta_ndiv / freq_table_step_size + 1;
	}

	num_freqs += (delta_ndiv % freq_table_step_size) ? 1 : 0;

	freq_table = devm_kcalloc(&pdev->dev, num_freqs + 1,
				  sizeof(*freq_table), GFP_KERNEL);
	if (!freq_table)
		return ERR_PTR(-ENOMEM);

	for (index = 0, ndiv = resp.ndiv_min;
			ndiv < resp.ndiv_max;
			index++, ndiv += freq_table_step_size) {
		freq_table[index].driver_data = ndiv;
		freq_table[index].frequency = map_ndiv_to_freq(&resp, ndiv);
	}

	freq_table[index].driver_data = resp.ndiv_max;
	freq_table[index++].frequency = map_ndiv_to_freq(&resp, resp.ndiv_max);
	freq_table[index].frequency = CPUFREQ_TABLE_END;

	return freq_table;
}

static int tegra194_cpufreq_probe(struct platform_device *pdev)
{
	struct tegra194_cpufreq_data *data;
	struct tegra_bpmp *bpmp;
	int err, i;

	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->num_clusters = MAX_CLUSTERS;
	data->tables = devm_kcalloc(&pdev->dev, data->num_clusters,
				    sizeof(*data->tables), GFP_KERNEL);
	if (!data->tables)
		return -ENOMEM;

	platform_set_drvdata(pdev, data);

	bpmp = tegra_bpmp_get(&pdev->dev);
	if (IS_ERR(bpmp))
		return PTR_ERR(bpmp);

	read_counters_wq = alloc_workqueue("read_counters_wq", __WQ_LEGACY, 1);
	if (!read_counters_wq) {
		dev_err(&pdev->dev, "fail to create_workqueue\n");
		err = -EINVAL;
		goto put_bpmp;
	}

	for (i = 0; i < data->num_clusters; i++) {
		data->tables[i] = init_freq_table(pdev, bpmp, i);
		if (IS_ERR(data->tables[i])) {
			err = PTR_ERR(data->tables[i]);
			goto err_free_res;
		}
	}

	tegra194_cpufreq_driver.driver_data = data;

	err = cpufreq_register_driver(&tegra194_cpufreq_driver);
	if (!err)
		goto put_bpmp;

err_free_res:
	tegra194_cpufreq_free_resources();
put_bpmp:
	tegra_bpmp_put(bpmp);
	return err;
}

static int tegra194_cpufreq_remove(struct platform_device *pdev)
{
	cpufreq_unregister_driver(&tegra194_cpufreq_driver);
	tegra194_cpufreq_free_resources();

	return 0;
}

static const struct of_device_id tegra194_cpufreq_of_match[] = {
	{ .compatible = "nvidia,tegra194-ccplex", },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, tegra194_cpufreq_of_match);

static struct platform_driver tegra194_ccplex_driver = {
	.driver = {
		.name = "tegra194-cpufreq",
		.of_match_table = tegra194_cpufreq_of_match,
	},
	.probe = tegra194_cpufreq_probe,
	.remove = tegra194_cpufreq_remove,
};
module_platform_driver(tegra194_ccplex_driver);

MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>");
MODULE_AUTHOR("Sumit Gupta <sumitg@nvidia.com>");
MODULE_DESCRIPTION("NVIDIA Tegra194 cpufreq driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
df320f89 SG	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* Copyright (c) 2020, NVIDIA CORPORATION. All rights reserved
	4	*/
	5
	6	#include <linux/cpu.h>
	7	#include <linux/cpufreq.h>
	8	#include <linux/delay.h>
	9	#include <linux/dma-mapping.h>
	10	#include <linux/module.h>
	11	#include <linux/of.h>
	12	#include <linux/of_platform.h>
	13	#include <linux/platform_device.h>
	14	#include <linux/slab.h>
	15
	16	#include <asm/smp_plat.h>
	17
	18	#include <soc/tegra/bpmp.h>
	19	#include <soc/tegra/bpmp-abi.h>
	20
	21	#define KHZ 1000
	22	#define REF_CLK_MHZ 408 /* 408 MHz */
	23	#define US_DELAY 500
df320f89 SG	24	#define CPUFREQ_TBL_STEP_HZ (50 * KHZ * KHZ)
	25	#define MAX_CNT ~0U
	26
	27	/* cpufreq transisition latency */
	28	#define TEGRA_CPUFREQ_TRANSITION_LATENCY (300 * 1000) /* unit in nanoseconds */
	29
	30	enum cluster {
	31	CLUSTER0,
	32	CLUSTER1,
	33	CLUSTER2,
	34	CLUSTER3,
	35	MAX_CLUSTERS,
	36	};
	37
	38	struct tegra194_cpufreq_data {
	39	void __iomem *regs;
	40	size_t num_clusters;
	41	struct cpufreq_frequency_table **tables;
	42	};
	43
	44	struct tegra_cpu_ctr {
	45	u32 cpu;
df320f89 SG	46	u32 coreclk_cnt, last_coreclk_cnt;
	47	u32 refclk_cnt, last_refclk_cnt;
	48	};
	49
	50	struct read_counters_work {
	51	struct work_struct work;
	52	struct tegra_cpu_ctr c;
	53	};
	54
	55	static struct workqueue_struct *read_counters_wq;
	56
93d0c1ab	57	static void get_cpu_cluster(void *cluster)
df320f89	58	{
93d0c1ab SG	59	u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK;
	60
	61	((uint32_t )cluster) = MPIDR_AFFINITY_LEVEL(mpidr, 1);
df320f89 SG	62	}
	63
	64	/*
	65	* Read per-core Read-only system register NVFREQ_FEEDBACK_EL1.
	66	* The register provides frequency feedback information to
	67	* determine the average actual frequency a core has run at over
	68	* a period of time.
	69	* [31:0] PLLP counter: Counts at fixed frequency (408 MHz)
	70	* [63:32] Core clock counter: counts on every core clock cycle
	71	* where the core is architecturally clocking
	72	*/
	73	static u64 read_freq_feedback(void)
	74	{
	75	u64 val = 0;
	76
	77	asm volatile("mrs %0, s3_0_c15_c0_5" : "=r" (val) : );
	78
	79	return val;
	80	}
	81
	82	static inline u32 map_ndiv_to_freq(struct mrq_cpu_ndiv_limits_response
	83	*nltbl, u16 ndiv)
	84	{
	85	return nltbl->ref_clk_hz / KHZ * ndiv / (nltbl->pdiv * nltbl->mdiv);
	86	}
	87
	88	static void tegra_read_counters(struct work_struct *work)
	89	{
	90	struct read_counters_work *read_counters_work;
	91	struct tegra_cpu_ctr *c;
	92	u64 val;
	93
	94	/*
	95	* ref_clk_counter(32 bit counter) runs on constant clk,
	96	* pll_p(408MHz).
	97	* It will take = 2 ^ 32 / 408 MHz to overflow ref clk counter
	98	* = 10526880 usec = 10.527 sec to overflow
	99	*
	100	* Like wise core_clk_counter(32 bit counter) runs on core clock.
	101	* It's synchronized to crab_clk (cpu_crab_clk) which runs at
	102	* freq of cluster. Assuming max cluster clock ~2000MHz,
	103	* It will take = 2 ^ 32 / 2000 MHz to overflow core clk counter
	104	* = ~2.147 sec to overflow
	105	*/
	106	read_counters_work = container_of(work, struct read_counters_work,
	107	work);
	108	c = &read_counters_work->c;
	109
	110	val = read_freq_feedback();
	111	c->last_refclk_cnt = lower_32_bits(val);
	112	c->last_coreclk_cnt = upper_32_bits(val);
93549516	113	udelay(US_DELAY);
df320f89 SG	114	val = read_freq_feedback();
	115	c->refclk_cnt = lower_32_bits(val);
	116	c->coreclk_cnt = upper_32_bits(val);
	117	}
	118
	119	/*
	120	* Return instantaneous cpu speed
	121	* Instantaneous freq is calculated as -
	122	* -Takes sample on every query of getting the freq.
	123	* - Read core and ref clock counters;
	124	* - Delay for X us
	125	* - Read above cycle counters again
	126	* - Calculates freq by subtracting current and previous counters
	127	* divided by the delay time or eqv. of ref_clk_counter in delta time
	128	* - Return Kcycles/second, freq in KHz
	129	*
	130	* delta time period = x sec
	131	* = delta ref_clk_counter / (408 * 10^6) sec
	132	* freq in Hz = cycles/sec
	133	* = (delta cycles / x sec
	134	* = (delta cycles * 408 * 10^6) / delta ref_clk_counter
	135	* in KHz = (delta cycles * 408 * 10^3) / delta ref_clk_counter
	136	*
	137	* @cpu - logical cpu whose freq to be updated
	138	* Returns freq in KHz on success, 0 if cpu is offline
	139	*/
f45f89a7	140	static unsigned int tegra194_calculate_speed(u32 cpu)
df320f89 SG	141	{
	142	struct read_counters_work read_counters_work;
	143	struct tegra_cpu_ctr c;
	144	u32 delta_refcnt;
	145	u32 delta_ccnt;
	146	u32 rate_mhz;
	147
	148	/*
	149	* udelay() is required to reconstruct cpu frequency over an
	150	* observation window. Using workqueue to call udelay() with
	151	* interrupts enabled.
	152	*/
	153	read_counters_work.c.cpu = cpu;
df320f89 SG	154	INIT_WORK_ONSTACK(&read_counters_work.work, tegra_read_counters);
	155	queue_work_on(cpu, read_counters_wq, &read_counters_work.work);
	156	flush_work(&read_counters_work.work);
	157	c = read_counters_work.c;
	158
	159	if (c.coreclk_cnt < c.last_coreclk_cnt)
	160	delta_ccnt = c.coreclk_cnt + (MAX_CNT - c.last_coreclk_cnt);
	161	else
	162	delta_ccnt = c.coreclk_cnt - c.last_coreclk_cnt;
	163	if (!delta_ccnt)
	164	return 0;
	165
	166	/* ref clock is 32 bits */
	167	if (c.refclk_cnt < c.last_refclk_cnt)
	168	delta_refcnt = c.refclk_cnt + (MAX_CNT - c.last_refclk_cnt);
	169	else
	170	delta_refcnt = c.refclk_cnt - c.last_refclk_cnt;
	171	if (!delta_refcnt) {
	172	pr_debug("cpufreq: %d is idle, delta_refcnt: 0\n", cpu);
	173	return 0;
	174	}
	175	rate_mhz = ((unsigned long)(delta_ccnt * REF_CLK_MHZ)) / delta_refcnt;
	176
	177	return (rate_mhz * KHZ); /* in KHz */
	178	}
	179
68b9cd72 SG	180	static void get_cpu_ndiv(void *ndiv)
	181	{
	182	u64 ndiv_val;
	183
	184	asm volatile("mrs %0, s3_0_c15_c0_4" : "=r" (ndiv_val) : );
	185
	186	(u64 )ndiv = ndiv_val;
	187	}
	188
	189	static void set_cpu_ndiv(void *data)
	190	{
	191	struct cpufreq_frequency_table *tbl = data;
	192	u64 ndiv_val = (u64)tbl->driver_data;
	193
	194	asm volatile("msr s3_0_c15_c0_4, %0" : : "r" (ndiv_val));
	195	}
	196
df320f89 SG	197	static unsigned int tegra194_get_speed(u32 cpu)
df320f89 SG	198	{
68b9cd72 SG	199	struct tegra194_cpufreq_data *data = cpufreq_get_driver_data();
	200	struct cpufreq_frequency_table *pos;
	201	unsigned int rate;
	202	u64 ndiv;
	203	int ret;
	204	u32 cl;
	205
	206	smp_call_function_single(cpu, get_cpu_cluster, &cl, true);
	207
	208	/* reconstruct actual cpu freq using counters */
f45f89a7	209	rate = tegra194_calculate_speed(cpu);
68b9cd72 SG	210
	211	/* get last written ndiv value */
	212	ret = smp_call_function_single(cpu, get_cpu_ndiv, &ndiv, true);
	213	if (WARN_ON_ONCE(ret))
	214	return rate;
	215
	216	/*
	217	* If the reconstructed frequency has acceptable delta from
	218	* the last written value, then return freq corresponding
	219	* to the last written ndiv value from freq_table. This is
	220	* done to return consistent value.
	221	*/
	222	cpufreq_for_each_valid_entry(pos, data->tables[cl]) {
	223	if (pos->driver_data != ndiv)
	224	continue;
	225
	226	if (abs(pos->frequency - rate) > 115200) {
	227	pr_warn("cpufreq: cpu%d,cur:%u,set:%u,set ndiv:%llu\n",
	228	cpu, rate, pos->frequency, ndiv);
	229	} else {
	230	rate = pos->frequency;
	231	}
	232	break;
	233	}
	234	return rate;
df320f89 SG	235	}
	236
	237	static int tegra194_cpufreq_init(struct cpufreq_policy *policy)
	238	{
	239	struct tegra194_cpufreq_data *data = cpufreq_get_driver_data();
df320f89	240	u32 cpu;
93d0c1ab SG	241	u32 cl;
	242
	243	smp_call_function_single(policy->cpu, get_cpu_cluster, &cl, true);
df320f89	244
c2ace21f	245	if (cl >= data->num_clusters \|\| !data->tables[cl])
df320f89 SG	246	return -EINVAL;
df320f89 SG	247
df320f89 SG	248	/* set same policy for all cpus in a cluster */
	249	for (cpu = (cl * 2); cpu < ((cl + 1) * 2); cpu++)
	250	cpumask_set_cpu(cpu, policy->cpus);
	251
	252	policy->freq_table = data->tables[cl];
	253	policy->cpuinfo.transition_latency = TEGRA_CPUFREQ_TRANSITION_LATENCY;
	254
	255	return 0;
	256	}
	257
df320f89 SG	258	static int tegra194_cpufreq_set_target(struct cpufreq_policy *policy,
	259	unsigned int index)
	260	{
	261	struct cpufreq_frequency_table *tbl = policy->freq_table + index;
	262
	263	/*
	264	* Each core writes frequency in per core register. Then both cores
	265	* in a cluster run at same frequency which is the maximum frequency
	266	* request out of the values requested by both cores in that cluster.
	267	*/
	268	on_each_cpu_mask(policy->cpus, set_cpu_ndiv, tbl, true);
	269
	270	return 0;
	271	}
	272
	273	static struct cpufreq_driver tegra194_cpufreq_driver = {
	274	.name = "tegra194",
5ae4a4b4	275	.flags = CPUFREQ_CONST_LOOPS \| CPUFREQ_NEED_INITIAL_FREQ_CHECK,
df320f89 SG	276	.verify = cpufreq_generic_frequency_table_verify,
	277	.target_index = tegra194_cpufreq_set_target,
	278	.get = tegra194_get_speed,
	279	.init = tegra194_cpufreq_init,
	280	.attr = cpufreq_generic_attr,
	281	};
	282
	283	static void tegra194_cpufreq_free_resources(void)
	284	{
	285	destroy_workqueue(read_counters_wq);
	286	}
	287
	288	static struct cpufreq_frequency_table *
	289	init_freq_table(struct platform_device pdev, struct tegra_bpmp bpmp,
	290	unsigned int cluster_id)
	291	{
	292	struct cpufreq_frequency_table *freq_table;
	293	struct mrq_cpu_ndiv_limits_response resp;
	294	unsigned int num_freqs, ndiv, delta_ndiv;
	295	struct mrq_cpu_ndiv_limits_request req;
	296	struct tegra_bpmp_message msg;
	297	u16 freq_table_step_size;
	298	int err, index;
	299
	300	memset(&req, 0, sizeof(req));
	301	req.cluster_id = cluster_id;
	302
	303	memset(&msg, 0, sizeof(msg));
	304	msg.mrq = MRQ_CPU_NDIV_LIMITS;
	305	msg.tx.data = &req;
	306	msg.tx.size = sizeof(req);
	307	msg.rx.data = &resp;
	308	msg.rx.size = sizeof(resp);
	309
	310	err = tegra_bpmp_transfer(bpmp, &msg);
	311	if (err)
	312	return ERR_PTR(err);
c2ace21f MP	313	if (msg.rx.ret == -BPMP_EINVAL) {
	314	/* Cluster not available */
	315	return NULL;
	316	}
	317	if (msg.rx.ret)
	318	return ERR_PTR(-EINVAL);
df320f89 SG	319
	320	/*
	321	* Make sure frequency table step is a multiple of mdiv to match
	322	* vhint table granularity.
	323	*/
	324	freq_table_step_size = resp.mdiv *
	325	DIV_ROUND_UP(CPUFREQ_TBL_STEP_HZ, resp.ref_clk_hz);
	326
	327	dev_dbg(&pdev->dev, "cluster %d: frequency table step size: %d\n",
	328	cluster_id, freq_table_step_size);
	329
	330	delta_ndiv = resp.ndiv_max - resp.ndiv_min;
	331
	332	if (unlikely(delta_ndiv == 0)) {
	333	num_freqs = 1;
	334	} else {
	335	/* We store both ndiv_min and ndiv_max hence the +1 */
	336	num_freqs = delta_ndiv / freq_table_step_size + 1;
	337	}
	338
	339	num_freqs += (delta_ndiv % freq_table_step_size) ? 1 : 0;
	340
	341	freq_table = devm_kcalloc(&pdev->dev, num_freqs + 1,
	342	sizeof(*freq_table), GFP_KERNEL);
	343	if (!freq_table)
	344	return ERR_PTR(-ENOMEM);
	345
	346	for (index = 0, ndiv = resp.ndiv_min;
	347	ndiv < resp.ndiv_max;
	348	index++, ndiv += freq_table_step_size) {
	349	freq_table[index].driver_data = ndiv;
	350	freq_table[index].frequency = map_ndiv_to_freq(&resp, ndiv);
	351	}
	352
	353	freq_table[index].driver_data = resp.ndiv_max;
	354	freq_table[index++].frequency = map_ndiv_to_freq(&resp, resp.ndiv_max);
	355	freq_table[index].frequency = CPUFREQ_TABLE_END;
	356
	357	return freq_table;
	358	}
	359
	360	static int tegra194_cpufreq_probe(struct platform_device *pdev)
	361	{
	362	struct tegra194_cpufreq_data *data;
	363	struct tegra_bpmp *bpmp;
	364	int err, i;
	365
	366	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
	367	if (!data)
	368	return -ENOMEM;
	369
	370	data->num_clusters = MAX_CLUSTERS;
	371	data->tables = devm_kcalloc(&pdev->dev, data->num_clusters,
	372	sizeof(*data->tables), GFP_KERNEL);
	373	if (!data->tables)
	374	return -ENOMEM;
	375
	376	platform_set_drvdata(pdev, data);
	377
	378	bpmp = tegra_bpmp_get(&pdev->dev);
	379	if (IS_ERR(bpmp))
	380	return PTR_ERR(bpmp);
	381
	382	read_counters_wq = alloc_workqueue("read_counters_wq", __WQ_LEGACY, 1);
383	if (!read_counters_wq) {
384	dev_err(&pdev->dev, "fail to create_workqueue\n");
385	err = -EINVAL;
386	goto put_bpmp;
387	}
388
389	for (i = 0; i < data->num_clusters; i++) {
390	data->tables[i] = init_freq_table(pdev, bpmp, i);
391	if (IS_ERR(data->tables[i])) {
392	err = PTR_ERR(data->tables[i]);
393	goto err_free_res;
394	}
395	}
396
397	tegra194_cpufreq_driver.driver_data = data;
398
399	err = cpufreq_register_driver(&tegra194_cpufreq_driver);
400	if (!err)
401	goto put_bpmp;
402
403	err_free_res:
404	tegra194_cpufreq_free_resources();
405	put_bpmp:
406	tegra_bpmp_put(bpmp);
407	return err;
408	}
409
410	static int tegra194_cpufreq_remove(struct platform_device *pdev)
411	{
412	cpufreq_unregister_driver(&tegra194_cpufreq_driver);
413	tegra194_cpufreq_free_resources();
414
415	return 0;
416	}
417
418	static const struct of_device_id tegra194_cpufreq_of_match[] = {
419	{ .compatible = "nvidia,tegra194-ccplex", },
420	{ /* sentinel */ }
421	};
422	MODULE_DEVICE_TABLE(of, tegra194_cpufreq_of_match);
423
424	static struct platform_driver tegra194_ccplex_driver = {
425	.driver = {
426	.name = "tegra194-cpufreq",
427	.of_match_table = tegra194_cpufreq_of_match,
428	},
429	.probe = tegra194_cpufreq_probe,
430	.remove = tegra194_cpufreq_remove,
431	};
432	module_platform_driver(tegra194_ccplex_driver);
433
434	MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>");
435	MODULE_AUTHOR("Sumit Gupta <sumitg@nvidia.com>");
436	MODULE_DESCRIPTION("NVIDIA Tegra194 cpufreq driver");
437	MODULE_LICENSE("GPL v2");