xref: /linux/drivers/cpufreq/tegra186-cpufreq.c (revision f694f30e81c4ade358eb8c75273bac1a48f0cb8f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2017, NVIDIA CORPORATION. All rights reserved
4  */
5 
6 #include <linux/cpufreq.h>
7 #include <linux/dma-mapping.h>
8 #include <linux/module.h>
9 #include <linux/of.h>
10 #include <linux/platform_device.h>
11 
12 #include <soc/tegra/bpmp.h>
13 #include <soc/tegra/bpmp-abi.h>
14 
15 #define TEGRA186_NUM_CLUSTERS		2
16 #define EDVD_OFFSET_A57(core)		((SZ_64K * 6) + (0x20 + (core) * 0x4))
17 #define EDVD_OFFSET_DENVER(core)	((SZ_64K * 7) + (0x20 + (core) * 0x4))
18 #define EDVD_CORE_VOLT_FREQ_F_SHIFT	0
19 #define EDVD_CORE_VOLT_FREQ_F_MASK	0xffff
20 #define EDVD_CORE_VOLT_FREQ_V_SHIFT	16
21 
22 struct tegra186_cpufreq_cpu {
23 	unsigned int bpmp_cluster_id;
24 	unsigned int edvd_offset;
25 };
26 
27 static const struct tegra186_cpufreq_cpu tegra186_cpus[] = {
28 	/* CPU0 - A57 Cluster */
29 	{
30 		.bpmp_cluster_id = 1,
31 		.edvd_offset = EDVD_OFFSET_A57(0)
32 	},
33 	/* CPU1 - Denver Cluster */
34 	{
35 		.bpmp_cluster_id = 0,
36 		.edvd_offset = EDVD_OFFSET_DENVER(0)
37 	},
38 	/* CPU2 - Denver Cluster */
39 	{
40 		.bpmp_cluster_id = 0,
41 		.edvd_offset = EDVD_OFFSET_DENVER(1)
42 	},
43 	/* CPU3 - A57 Cluster */
44 	{
45 		.bpmp_cluster_id = 1,
46 		.edvd_offset = EDVD_OFFSET_A57(1)
47 	},
48 	/* CPU4 - A57 Cluster */
49 	{
50 		.bpmp_cluster_id = 1,
51 		.edvd_offset = EDVD_OFFSET_A57(2)
52 	},
53 	/* CPU5 - A57 Cluster */
54 	{
55 		.bpmp_cluster_id = 1,
56 		.edvd_offset = EDVD_OFFSET_A57(3)
57 	},
58 };
59 
60 struct tegra186_cpufreq_cluster {
61 	struct cpufreq_frequency_table *table;
62 	u32 ref_clk_khz;
63 	u32 div;
64 };
65 
66 struct tegra186_cpufreq_data {
67 	void __iomem *regs;
68 	const struct tegra186_cpufreq_cpu *cpus;
69 	struct tegra186_cpufreq_cluster clusters[];
70 };
71 
72 static int tegra186_cpufreq_init(struct cpufreq_policy *policy)
73 {
74 	struct tegra186_cpufreq_data *data = cpufreq_get_driver_data();
75 	unsigned int cluster = data->cpus[policy->cpu].bpmp_cluster_id;
76 	u32 cpu;
77 
78 	policy->freq_table = data->clusters[cluster].table;
79 	policy->cpuinfo.transition_latency = 300 * 1000;
80 	policy->driver_data = NULL;
81 
82 	/* set same policy for all cpus in a cluster */
83 	for (cpu = 0; cpu < ARRAY_SIZE(tegra186_cpus); cpu++) {
84 		if (data->cpus[cpu].bpmp_cluster_id == cluster)
85 			cpumask_set_cpu(cpu, policy->cpus);
86 	}
87 
88 	return 0;
89 }
90 
91 static int tegra186_cpufreq_set_target(struct cpufreq_policy *policy,
92 				       unsigned int index)
93 {
94 	struct tegra186_cpufreq_data *data = cpufreq_get_driver_data();
95 	struct cpufreq_frequency_table *tbl = policy->freq_table + index;
96 	unsigned int edvd_offset = data->cpus[policy->cpu].edvd_offset;
97 	u32 edvd_val = tbl->driver_data;
98 
99 	writel(edvd_val, data->regs + edvd_offset);
100 
101 	return 0;
102 }
103 
104 static unsigned int tegra186_cpufreq_get(unsigned int cpu)
105 {
106 	struct tegra186_cpufreq_data *data = cpufreq_get_driver_data();
107 	struct tegra186_cpufreq_cluster *cluster;
108 	struct cpufreq_policy *policy;
109 	unsigned int edvd_offset, cluster_id;
110 	u32 ndiv;
111 
112 	policy = cpufreq_cpu_get(cpu);
113 	if (!policy)
114 		return 0;
115 
116 	edvd_offset = data->cpus[policy->cpu].edvd_offset;
117 	ndiv = readl(data->regs + edvd_offset) & EDVD_CORE_VOLT_FREQ_F_MASK;
118 	cluster_id = data->cpus[policy->cpu].bpmp_cluster_id;
119 	cluster = &data->clusters[cluster_id];
120 	cpufreq_cpu_put(policy);
121 
122 	return (cluster->ref_clk_khz * ndiv) / cluster->div;
123 }
124 
125 static struct cpufreq_driver tegra186_cpufreq_driver = {
126 	.name = "tegra186",
127 	.flags = CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
128 			CPUFREQ_NEED_INITIAL_FREQ_CHECK,
129 	.get = tegra186_cpufreq_get,
130 	.verify = cpufreq_generic_frequency_table_verify,
131 	.target_index = tegra186_cpufreq_set_target,
132 	.init = tegra186_cpufreq_init,
133 };
134 
135 static struct cpufreq_frequency_table *init_vhint_table(
136 	struct platform_device *pdev, struct tegra_bpmp *bpmp,
137 	struct tegra186_cpufreq_cluster *cluster, unsigned int cluster_id)
138 {
139 	struct cpufreq_frequency_table *table;
140 	struct mrq_cpu_vhint_request req;
141 	struct tegra_bpmp_message msg;
142 	struct cpu_vhint_data *data;
143 	int err, i, j, num_rates = 0;
144 	dma_addr_t phys;
145 	void *virt;
146 
147 	virt = dma_alloc_coherent(bpmp->dev, sizeof(*data), &phys,
148 				  GFP_KERNEL);
149 	if (!virt)
150 		return ERR_PTR(-ENOMEM);
151 
152 	data = (struct cpu_vhint_data *)virt;
153 
154 	memset(&req, 0, sizeof(req));
155 	req.addr = phys;
156 	req.cluster_id = cluster_id;
157 
158 	memset(&msg, 0, sizeof(msg));
159 	msg.mrq = MRQ_CPU_VHINT;
160 	msg.tx.data = &req;
161 	msg.tx.size = sizeof(req);
162 
163 	err = tegra_bpmp_transfer(bpmp, &msg);
164 	if (err) {
165 		table = ERR_PTR(err);
166 		goto free;
167 	}
168 	if (msg.rx.ret) {
169 		table = ERR_PTR(-EINVAL);
170 		goto free;
171 	}
172 
173 	for (i = data->vfloor; i <= data->vceil; i++) {
174 		u16 ndiv = data->ndiv[i];
175 
176 		if (ndiv < data->ndiv_min || ndiv > data->ndiv_max)
177 			continue;
178 
179 		/* Only store lowest voltage index for each rate */
180 		if (i > 0 && ndiv == data->ndiv[i - 1])
181 			continue;
182 
183 		num_rates++;
184 	}
185 
186 	table = devm_kcalloc(&pdev->dev, num_rates + 1, sizeof(*table),
187 			     GFP_KERNEL);
188 	if (!table) {
189 		table = ERR_PTR(-ENOMEM);
190 		goto free;
191 	}
192 
193 	cluster->ref_clk_khz = data->ref_clk_hz / 1000;
194 	cluster->div = data->pdiv * data->mdiv;
195 
196 	for (i = data->vfloor, j = 0; i <= data->vceil; i++) {
197 		struct cpufreq_frequency_table *point;
198 		u16 ndiv = data->ndiv[i];
199 		u32 edvd_val = 0;
200 
201 		if (ndiv < data->ndiv_min || ndiv > data->ndiv_max)
202 			continue;
203 
204 		/* Only store lowest voltage index for each rate */
205 		if (i > 0 && ndiv == data->ndiv[i - 1])
206 			continue;
207 
208 		edvd_val |= i << EDVD_CORE_VOLT_FREQ_V_SHIFT;
209 		edvd_val |= ndiv << EDVD_CORE_VOLT_FREQ_F_SHIFT;
210 
211 		point = &table[j++];
212 		point->driver_data = edvd_val;
213 		point->frequency = (cluster->ref_clk_khz * ndiv) / cluster->div;
214 	}
215 
216 	table[j].frequency = CPUFREQ_TABLE_END;
217 
218 free:
219 	dma_free_coherent(bpmp->dev, sizeof(*data), virt, phys);
220 
221 	return table;
222 }
223 
224 static int tegra186_cpufreq_probe(struct platform_device *pdev)
225 {
226 	struct tegra186_cpufreq_data *data;
227 	struct tegra_bpmp *bpmp;
228 	unsigned int i = 0, err;
229 
230 	data = devm_kzalloc(&pdev->dev,
231 			    struct_size(data, clusters, TEGRA186_NUM_CLUSTERS),
232 			    GFP_KERNEL);
233 	if (!data)
234 		return -ENOMEM;
235 
236 	data->cpus = tegra186_cpus;
237 
238 	bpmp = tegra_bpmp_get(&pdev->dev);
239 	if (IS_ERR(bpmp))
240 		return PTR_ERR(bpmp);
241 
242 	data->regs = devm_platform_ioremap_resource(pdev, 0);
243 	if (IS_ERR(data->regs)) {
244 		err = PTR_ERR(data->regs);
245 		goto put_bpmp;
246 	}
247 
248 	for (i = 0; i < TEGRA186_NUM_CLUSTERS; i++) {
249 		struct tegra186_cpufreq_cluster *cluster = &data->clusters[i];
250 
251 		cluster->table = init_vhint_table(pdev, bpmp, cluster, i);
252 		if (IS_ERR(cluster->table)) {
253 			err = PTR_ERR(cluster->table);
254 			goto put_bpmp;
255 		}
256 	}
257 
258 	tegra186_cpufreq_driver.driver_data = data;
259 
260 	err = cpufreq_register_driver(&tegra186_cpufreq_driver);
261 
262 put_bpmp:
263 	tegra_bpmp_put(bpmp);
264 
265 	return err;
266 }
267 
268 static void tegra186_cpufreq_remove(struct platform_device *pdev)
269 {
270 	cpufreq_unregister_driver(&tegra186_cpufreq_driver);
271 }
272 
273 static const struct of_device_id tegra186_cpufreq_of_match[] = {
274 	{ .compatible = "nvidia,tegra186-ccplex-cluster", },
275 	{ }
276 };
277 MODULE_DEVICE_TABLE(of, tegra186_cpufreq_of_match);
278 
279 static struct platform_driver tegra186_cpufreq_platform_driver = {
280 	.driver = {
281 		.name = "tegra186-cpufreq",
282 		.of_match_table = tegra186_cpufreq_of_match,
283 	},
284 	.probe = tegra186_cpufreq_probe,
285 	.remove = tegra186_cpufreq_remove,
286 };
287 module_platform_driver(tegra186_cpufreq_platform_driver);
288 
289 MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>");
290 MODULE_DESCRIPTION("NVIDIA Tegra186 cpufreq driver");
291 MODULE_LICENSE("GPL v2");
292