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 
77 	policy->freq_table = data->clusters[cluster].table;
78 	policy->cpuinfo.transition_latency = 300 * 1000;
79 	policy->driver_data = NULL;
80 
81 	return 0;
82 }
83 
84 static int tegra186_cpufreq_set_target(struct cpufreq_policy *policy,
85 				       unsigned int index)
86 {
87 	struct tegra186_cpufreq_data *data = cpufreq_get_driver_data();
88 	struct cpufreq_frequency_table *tbl = policy->freq_table + index;
89 	unsigned int edvd_offset = data->cpus[policy->cpu].edvd_offset;
90 	u32 edvd_val = tbl->driver_data;
91 
92 	writel(edvd_val, data->regs + edvd_offset);
93 
94 	return 0;
95 }
96 
97 static unsigned int tegra186_cpufreq_get(unsigned int cpu)
98 {
99 	struct tegra186_cpufreq_data *data = cpufreq_get_driver_data();
100 	struct tegra186_cpufreq_cluster *cluster;
101 	struct cpufreq_policy *policy;
102 	unsigned int edvd_offset, cluster_id;
103 	u32 ndiv;
104 
105 	policy = cpufreq_cpu_get(cpu);
106 	if (!policy)
107 		return 0;
108 
109 	edvd_offset = data->cpus[policy->cpu].edvd_offset;
110 	ndiv = readl(data->regs + edvd_offset) & EDVD_CORE_VOLT_FREQ_F_MASK;
111 	cluster_id = data->cpus[policy->cpu].bpmp_cluster_id;
112 	cluster = &data->clusters[cluster_id];
113 	cpufreq_cpu_put(policy);
114 
115 	return (cluster->ref_clk_khz * ndiv) / cluster->div;
116 }
117 
118 static struct cpufreq_driver tegra186_cpufreq_driver = {
119 	.name = "tegra186",
120 	.flags = CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
121 			CPUFREQ_NEED_INITIAL_FREQ_CHECK,
122 	.get = tegra186_cpufreq_get,
123 	.verify = cpufreq_generic_frequency_table_verify,
124 	.target_index = tegra186_cpufreq_set_target,
125 	.init = tegra186_cpufreq_init,
126 	.attr = cpufreq_generic_attr,
127 };
128 
129 static struct cpufreq_frequency_table *init_vhint_table(
130 	struct platform_device *pdev, struct tegra_bpmp *bpmp,
131 	struct tegra186_cpufreq_cluster *cluster, unsigned int cluster_id)
132 {
133 	struct cpufreq_frequency_table *table;
134 	struct mrq_cpu_vhint_request req;
135 	struct tegra_bpmp_message msg;
136 	struct cpu_vhint_data *data;
137 	int err, i, j, num_rates = 0;
138 	dma_addr_t phys;
139 	void *virt;
140 
141 	virt = dma_alloc_coherent(bpmp->dev, sizeof(*data), &phys,
142 				  GFP_KERNEL);
143 	if (!virt)
144 		return ERR_PTR(-ENOMEM);
145 
146 	data = (struct cpu_vhint_data *)virt;
147 
148 	memset(&req, 0, sizeof(req));
149 	req.addr = phys;
150 	req.cluster_id = cluster_id;
151 
152 	memset(&msg, 0, sizeof(msg));
153 	msg.mrq = MRQ_CPU_VHINT;
154 	msg.tx.data = &req;
155 	msg.tx.size = sizeof(req);
156 
157 	err = tegra_bpmp_transfer(bpmp, &msg);
158 	if (err) {
159 		table = ERR_PTR(err);
160 		goto free;
161 	}
162 	if (msg.rx.ret) {
163 		table = ERR_PTR(-EINVAL);
164 		goto free;
165 	}
166 
167 	for (i = data->vfloor; i <= data->vceil; i++) {
168 		u16 ndiv = data->ndiv[i];
169 
170 		if (ndiv < data->ndiv_min || ndiv > data->ndiv_max)
171 			continue;
172 
173 		/* Only store lowest voltage index for each rate */
174 		if (i > 0 && ndiv == data->ndiv[i - 1])
175 			continue;
176 
177 		num_rates++;
178 	}
179 
180 	table = devm_kcalloc(&pdev->dev, num_rates + 1, sizeof(*table),
181 			     GFP_KERNEL);
182 	if (!table) {
183 		table = ERR_PTR(-ENOMEM);
184 		goto free;
185 	}
186 
187 	cluster->ref_clk_khz = data->ref_clk_hz / 1000;
188 	cluster->div = data->pdiv * data->mdiv;
189 
190 	for (i = data->vfloor, j = 0; i <= data->vceil; i++) {
191 		struct cpufreq_frequency_table *point;
192 		u16 ndiv = data->ndiv[i];
193 		u32 edvd_val = 0;
194 
195 		if (ndiv < data->ndiv_min || ndiv > data->ndiv_max)
196 			continue;
197 
198 		/* Only store lowest voltage index for each rate */
199 		if (i > 0 && ndiv == data->ndiv[i - 1])
200 			continue;
201 
202 		edvd_val |= i << EDVD_CORE_VOLT_FREQ_V_SHIFT;
203 		edvd_val |= ndiv << EDVD_CORE_VOLT_FREQ_F_SHIFT;
204 
205 		point = &table[j++];
206 		point->driver_data = edvd_val;
207 		point->frequency = (cluster->ref_clk_khz * ndiv) / cluster->div;
208 	}
209 
210 	table[j].frequency = CPUFREQ_TABLE_END;
211 
212 free:
213 	dma_free_coherent(bpmp->dev, sizeof(*data), virt, phys);
214 
215 	return table;
216 }
217 
218 static int tegra186_cpufreq_probe(struct platform_device *pdev)
219 {
220 	struct tegra186_cpufreq_data *data;
221 	struct tegra_bpmp *bpmp;
222 	unsigned int i = 0, err;
223 
224 	data = devm_kzalloc(&pdev->dev,
225 			    struct_size(data, clusters, TEGRA186_NUM_CLUSTERS),
226 			    GFP_KERNEL);
227 	if (!data)
228 		return -ENOMEM;
229 
230 	data->cpus = tegra186_cpus;
231 
232 	bpmp = tegra_bpmp_get(&pdev->dev);
233 	if (IS_ERR(bpmp))
234 		return PTR_ERR(bpmp);
235 
236 	data->regs = devm_platform_ioremap_resource(pdev, 0);
237 	if (IS_ERR(data->regs)) {
238 		err = PTR_ERR(data->regs);
239 		goto put_bpmp;
240 	}
241 
242 	for (i = 0; i < TEGRA186_NUM_CLUSTERS; i++) {
243 		struct tegra186_cpufreq_cluster *cluster = &data->clusters[i];
244 
245 		cluster->table = init_vhint_table(pdev, bpmp, cluster, i);
246 		if (IS_ERR(cluster->table)) {
247 			err = PTR_ERR(cluster->table);
248 			goto put_bpmp;
249 		}
250 	}
251 
252 	tegra186_cpufreq_driver.driver_data = data;
253 
254 	err = cpufreq_register_driver(&tegra186_cpufreq_driver);
255 
256 put_bpmp:
257 	tegra_bpmp_put(bpmp);
258 
259 	return err;
260 }
261 
262 static void tegra186_cpufreq_remove(struct platform_device *pdev)
263 {
264 	cpufreq_unregister_driver(&tegra186_cpufreq_driver);
265 }
266 
267 static const struct of_device_id tegra186_cpufreq_of_match[] = {
268 	{ .compatible = "nvidia,tegra186-ccplex-cluster", },
269 	{ }
270 };
271 MODULE_DEVICE_TABLE(of, tegra186_cpufreq_of_match);
272 
273 static struct platform_driver tegra186_cpufreq_platform_driver = {
274 	.driver = {
275 		.name = "tegra186-cpufreq",
276 		.of_match_table = tegra186_cpufreq_of_match,
277 	},
278 	.probe = tegra186_cpufreq_probe,
279 	.remove_new = tegra186_cpufreq_remove,
280 };
281 module_platform_driver(tegra186_cpufreq_platform_driver);
282 
283 MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>");
284 MODULE_DESCRIPTION("NVIDIA Tegra186 cpufreq driver");
285 MODULE_LICENSE("GPL v2");
286