summaryrefslogtreecommitdiffstats
path: root/drivers/cpufreq/qcom-cpufreq-hw.c
blob: d83939a1b3d4cd7f4f12a70477eaced3e9bf487f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2018, The Linux Foundation. All rights reserved.
 */

#include <linux/bitfield.h>
#include <linux/cpufreq.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/slab.h>

#define LUT_MAX_ENTRIES			40U
#define LUT_SRC				GENMASK(31, 30)
#define LUT_L_VAL			GENMASK(7, 0)
#define LUT_CORE_COUNT			GENMASK(18, 16)
#define LUT_ROW_SIZE			32
#define CLK_HW_DIV			2

/* Register offsets */
#define REG_ENABLE			0x0
#define REG_LUT_TABLE			0x110
#define REG_PERF_STATE			0x920

static unsigned long cpu_hw_rate, xo_rate;
static struct platform_device *global_pdev;

static int qcom_cpufreq_hw_target_index(struct cpufreq_policy *policy,
					unsigned int index)
{
	void __iomem *perf_state_reg = policy->driver_data;

	writel_relaxed(index, perf_state_reg);

	return 0;
}

static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
{
	void __iomem *perf_state_reg;
	struct cpufreq_policy *policy;
	unsigned int index;

	policy = cpufreq_cpu_get_raw(cpu);
	if (!policy)
		return 0;

	perf_state_reg = policy->driver_data;

	index = readl_relaxed(perf_state_reg);
	index = min(index, LUT_MAX_ENTRIES - 1);

	return policy->freq_table[index].frequency;
}

static unsigned int qcom_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
						unsigned int target_freq)
{
	void __iomem *perf_state_reg = policy->driver_data;
	int index;

	index = policy->cached_resolved_idx;
	if (index < 0)
		return 0;

	writel_relaxed(index, perf_state_reg);

	return policy->freq_table[index].frequency;
}

static int qcom_cpufreq_hw_read_lut(struct device *dev,
				    struct cpufreq_policy *policy,
				    void __iomem *base)
{
	u32 data, src, lval, i, core_count, prev_cc = 0, prev_freq = 0, freq;
	unsigned int max_cores = cpumask_weight(policy->cpus);
	struct cpufreq_frequency_table	*table;

	table = kcalloc(LUT_MAX_ENTRIES + 1, sizeof(*table), GFP_KERNEL);
	if (!table)
		return -ENOMEM;

	for (i = 0; i < LUT_MAX_ENTRIES; i++) {
		data = readl_relaxed(base + REG_LUT_TABLE + i * LUT_ROW_SIZE);
		src = FIELD_GET(LUT_SRC, data);
		lval = FIELD_GET(LUT_L_VAL, data);
		core_count = FIELD_GET(LUT_CORE_COUNT, data);

		if (src)
			freq = xo_rate * lval / 1000;
		else
			freq = cpu_hw_rate / 1000;

		/* Ignore boosts in the middle of the table */
		if (core_count != max_cores) {
			table[i].frequency = CPUFREQ_ENTRY_INVALID;
		} else {
			table[i].frequency = freq;
			dev_dbg(dev, "index=%d freq=%d, core_count %d\n", i,
				freq, core_count);
		}

		/*
		 * Two of the same frequencies with the same core counts means
		 * end of table
		 */
		if (i > 0 && prev_freq == freq && prev_cc == core_count) {
			struct cpufreq_frequency_table *prev = &table[i - 1];

			/*
			 * Only treat the last frequency that might be a boost
			 * as the boost frequency
			 */
			if (prev_cc != max_cores) {
				prev->frequency = prev_freq;
				prev->flags = CPUFREQ_BOOST_FREQ;
			}

			break;
		}

		prev_cc = core_count;
		prev_freq = freq;
	}

	table[i].frequency = CPUFREQ_TABLE_END;
	policy->freq_table = table;

	return 0;
}

static void qcom_get_related_cpus(int index, struct cpumask *m)
{
	struct device_node *cpu_np;
	struct of_phandle_args args;
	int cpu, ret;

	for_each_possible_cpu(cpu) {
		cpu_np = of_cpu_device_node_get(cpu);
		if (!cpu_np)
			continue;

		ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
						 "#freq-domain-cells", 0,
						 &args);
		of_node_put(cpu_np);
		if (ret < 0)
			continue;

		if (index == args.args[0])
			cpumask_set_cpu(cpu, m);
	}
}

static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
{
	struct device *dev = &global_pdev->dev;
	struct of_phandle_args args;
	struct device_node *cpu_np;
	struct resource *res;
	void __iomem *base;
	int ret, index;

	cpu_np = of_cpu_device_node_get(policy->cpu);
	if (!cpu_np)
		return -EINVAL;

	ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
					 "#freq-domain-cells", 0, &args);
	of_node_put(cpu_np);
	if (ret)
		return ret;

	index = args.args[0];

	res = platform_get_resource(global_pdev, IORESOURCE_MEM, index);
	if (!res)
		return -ENODEV;

	base = devm_ioremap(dev, res->start, resource_size(res));
	if (!base)
		return -ENOMEM;

	/* HW should be in enabled state to proceed */
	if (!(readl_relaxed(base + REG_ENABLE) & 0x1)) {
		dev_err(dev, "Domain-%d cpufreq hardware not enabled\n", index);
		ret = -ENODEV;
		goto error;
	}

	qcom_get_related_cpus(index, policy->cpus);
	if (!cpumask_weight(policy->cpus)) {
		dev_err(dev, "Domain-%d failed to get related CPUs\n", index);
		ret = -ENOENT;
		goto error;
	}

	policy->driver_data = base + REG_PERF_STATE;

	ret = qcom_cpufreq_hw_read_lut(dev, policy, base);
	if (ret) {
		dev_err(dev, "Domain-%d failed to read LUT\n", index);
		goto error;
	}

	policy->fast_switch_possible = true;

	return 0;
error:
	devm_iounmap(dev, base);
	return ret;
}

static int qcom_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy)
{
	void __iomem *base = policy->driver_data - REG_PERF_STATE;

	kfree(policy->freq_table);
	devm_iounmap(&global_pdev->dev, base);

	return 0;
}

static struct freq_attr *qcom_cpufreq_hw_attr[] = {
	&cpufreq_freq_attr_scaling_available_freqs,
	&cpufreq_freq_attr_scaling_boost_freqs,
	NULL
};

static struct cpufreq_driver cpufreq_qcom_hw_driver = {
	.flags		= CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK |
			  CPUFREQ_HAVE_GOVERNOR_PER_POLICY,
	.verify		= cpufreq_generic_frequency_table_verify,
	.target_index	= qcom_cpufreq_hw_target_index,
	.get		= qcom_cpufreq_hw_get,
	.init		= qcom_cpufreq_hw_cpu_init,
	.exit		= qcom_cpufreq_hw_cpu_exit,
	.fast_switch    = qcom_cpufreq_hw_fast_switch,
	.name		= "qcom-cpufreq-hw",
	.attr		= qcom_cpufreq_hw_attr,
};

static int qcom_cpufreq_hw_driver_probe(struct platform_device *pdev)
{
	struct clk *clk;
	int ret;

	clk = clk_get(&pdev->dev, "xo");
	if (IS_ERR(clk))
		return PTR_ERR(clk);

	xo_rate = clk_get_rate(clk);
	clk_put(clk);

	clk = clk_get(&pdev->dev, "alternate");
	if (IS_ERR(clk))
		return PTR_ERR(clk);

	cpu_hw_rate = clk_get_rate(clk) / CLK_HW_DIV;
	clk_put(clk);

	global_pdev = pdev;

	ret = cpufreq_register_driver(&cpufreq_qcom_hw_driver);
	if (ret)
		dev_err(&pdev->dev, "CPUFreq HW driver failed to register\n");
	else
		dev_dbg(&pdev->dev, "QCOM CPUFreq HW driver initialized\n");

	return ret;
}

static int qcom_cpufreq_hw_driver_remove(struct platform_device *pdev)
{
	return cpufreq_unregister_driver(&cpufreq_qcom_hw_driver);
}

static const struct of_device_id qcom_cpufreq_hw_match[] = {
	{ .compatible = "qcom,cpufreq-hw" },
	{}
};
MODULE_DEVICE_TABLE(of, qcom_cpufreq_hw_match);

static struct platform_driver qcom_cpufreq_hw_driver = {
	.probe = qcom_cpufreq_hw_driver_probe,
	.remove = qcom_cpufreq_hw_driver_remove,
	.driver = {
		.name = "qcom-cpufreq-hw",
		.of_match_table = qcom_cpufreq_hw_match,
	},
};

static int __init qcom_cpufreq_hw_init(void)
{
	return platform_driver_register(&qcom_cpufreq_hw_driver);
}
subsys_initcall(qcom_cpufreq_hw_init);

static void __exit qcom_cpufreq_hw_exit(void)
{
	platform_driver_unregister(&qcom_cpufreq_hw_driver);
}
module_exit(qcom_cpufreq_hw_exit);

MODULE_DESCRIPTION("QCOM CPUFREQ HW Driver");
MODULE_LICENSE("GPL v2");