xref: /linux/drivers/cpufreq/tegra186-cpufreq.c (revision 7aacf86b75bc5523d20fd9127104384fce51ce9c)
1 /*
2  * Copyright (c) 2017, NVIDIA CORPORATION. All rights reserved
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  */
13 
14 #include <linux/cpufreq.h>
15 #include <linux/dma-mapping.h>
16 #include <linux/module.h>
17 #include <linux/of.h>
18 #include <linux/platform_device.h>
19 
20 #include <soc/tegra/bpmp.h>
21 #include <soc/tegra/bpmp-abi.h>
22 
23 #define EDVD_CORE_VOLT_FREQ(core)		(0x20 + (core) * 0x4)
24 #define EDVD_CORE_VOLT_FREQ_F_SHIFT		0
25 #define EDVD_CORE_VOLT_FREQ_V_SHIFT		16
26 
27 struct tegra186_cpufreq_cluster_info {
28 	unsigned long offset;
29 	int cpus[4];
30 	unsigned int bpmp_cluster_id;
31 };
32 
33 #define NO_CPU -1
34 static const struct tegra186_cpufreq_cluster_info tegra186_clusters[] = {
35 	/* Denver cluster */
36 	{
37 		.offset = SZ_64K * 7,
38 		.cpus = { 1, 2, NO_CPU, NO_CPU },
39 		.bpmp_cluster_id = 0,
40 	},
41 	/* A57 cluster */
42 	{
43 		.offset = SZ_64K * 6,
44 		.cpus = { 0, 3, 4, 5 },
45 		.bpmp_cluster_id = 1,
46 	},
47 };
48 
49 struct tegra186_cpufreq_cluster {
50 	const struct tegra186_cpufreq_cluster_info *info;
51 	struct cpufreq_frequency_table *table;
52 };
53 
54 struct tegra186_cpufreq_data {
55 	void __iomem *regs;
56 
57 	size_t num_clusters;
58 	struct tegra186_cpufreq_cluster *clusters;
59 };
60 
61 static int tegra186_cpufreq_init(struct cpufreq_policy *policy)
62 {
63 	struct tegra186_cpufreq_data *data = cpufreq_get_driver_data();
64 	unsigned int i;
65 
66 	for (i = 0; i < data->num_clusters; i++) {
67 		struct tegra186_cpufreq_cluster *cluster = &data->clusters[i];
68 		const struct tegra186_cpufreq_cluster_info *info =
69 			cluster->info;
70 		int core;
71 
72 		for (core = 0; core < ARRAY_SIZE(info->cpus); core++) {
73 			if (info->cpus[core] == policy->cpu)
74 				break;
75 		}
76 		if (core == ARRAY_SIZE(info->cpus))
77 			continue;
78 
79 		policy->driver_data =
80 			data->regs + info->offset + EDVD_CORE_VOLT_FREQ(core);
81 		cpufreq_table_validate_and_show(policy, cluster->table);
82 	}
83 
84 	policy->cpuinfo.transition_latency = 300 * 1000;
85 
86 	return 0;
87 }
88 
89 static int tegra186_cpufreq_set_target(struct cpufreq_policy *policy,
90 				       unsigned int index)
91 {
92 	struct cpufreq_frequency_table *tbl = policy->freq_table + index;
93 	void __iomem *edvd_reg = policy->driver_data;
94 	u32 edvd_val = tbl->driver_data;
95 
96 	writel(edvd_val, edvd_reg);
97 
98 	return 0;
99 }
100 
101 static struct cpufreq_driver tegra186_cpufreq_driver = {
102 	.name = "tegra186",
103 	.flags = CPUFREQ_STICKY | CPUFREQ_HAVE_GOVERNOR_PER_POLICY,
104 	.verify = cpufreq_generic_frequency_table_verify,
105 	.target_index = tegra186_cpufreq_set_target,
106 	.init = tegra186_cpufreq_init,
107 	.attr = cpufreq_generic_attr,
108 };
109 
110 static struct cpufreq_frequency_table *init_vhint_table(
111 	struct platform_device *pdev, struct tegra_bpmp *bpmp,
112 	unsigned int cluster_id)
113 {
114 	struct cpufreq_frequency_table *table;
115 	struct mrq_cpu_vhint_request req;
116 	struct tegra_bpmp_message msg;
117 	struct cpu_vhint_data *data;
118 	int err, i, j, num_rates = 0;
119 	dma_addr_t phys;
120 	void *virt;
121 
122 	virt = dma_alloc_coherent(bpmp->dev, sizeof(*data), &phys,
123 				  GFP_KERNEL | GFP_DMA32);
124 	if (!virt)
125 		return ERR_PTR(-ENOMEM);
126 
127 	data = (struct cpu_vhint_data *)virt;
128 
129 	memset(&req, 0, sizeof(req));
130 	req.addr = phys;
131 	req.cluster_id = cluster_id;
132 
133 	memset(&msg, 0, sizeof(msg));
134 	msg.mrq = MRQ_CPU_VHINT;
135 	msg.tx.data = &req;
136 	msg.tx.size = sizeof(req);
137 
138 	err = tegra_bpmp_transfer(bpmp, &msg);
139 	if (err) {
140 		table = ERR_PTR(err);
141 		goto free;
142 	}
143 
144 	for (i = data->vfloor; i <= data->vceil; i++) {
145 		u16 ndiv = data->ndiv[i];
146 
147 		if (ndiv < data->ndiv_min || ndiv > data->ndiv_max)
148 			continue;
149 
150 		/* Only store lowest voltage index for each rate */
151 		if (i > 0 && ndiv == data->ndiv[i - 1])
152 			continue;
153 
154 		num_rates++;
155 	}
156 
157 	table = devm_kcalloc(&pdev->dev, num_rates + 1, sizeof(*table),
158 			     GFP_KERNEL);
159 	if (!table) {
160 		table = ERR_PTR(-ENOMEM);
161 		goto free;
162 	}
163 
164 	for (i = data->vfloor, j = 0; i <= data->vceil; i++) {
165 		struct cpufreq_frequency_table *point;
166 		u16 ndiv = data->ndiv[i];
167 		u32 edvd_val = 0;
168 
169 		if (ndiv < data->ndiv_min || ndiv > data->ndiv_max)
170 			continue;
171 
172 		/* Only store lowest voltage index for each rate */
173 		if (i > 0 && ndiv == data->ndiv[i - 1])
174 			continue;
175 
176 		edvd_val |= i << EDVD_CORE_VOLT_FREQ_V_SHIFT;
177 		edvd_val |= ndiv << EDVD_CORE_VOLT_FREQ_F_SHIFT;
178 
179 		point = &table[j++];
180 		point->driver_data = edvd_val;
181 		point->frequency = data->ref_clk_hz * ndiv / data->pdiv /
182 			data->mdiv / 1000;
183 	}
184 
185 	table[j].frequency = CPUFREQ_TABLE_END;
186 
187 free:
188 	dma_free_coherent(bpmp->dev, sizeof(*data), virt, phys);
189 
190 	return table;
191 }
192 
193 static int tegra186_cpufreq_probe(struct platform_device *pdev)
194 {
195 	struct tegra186_cpufreq_data *data;
196 	struct tegra_bpmp *bpmp;
197 	struct resource *res;
198 	unsigned int i = 0, err;
199 
200 	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
201 	if (!data)
202 		return -ENOMEM;
203 
204 	data->clusters = devm_kcalloc(&pdev->dev, ARRAY_SIZE(tegra186_clusters),
205 				      sizeof(*data->clusters), GFP_KERNEL);
206 	if (!data->clusters)
207 		return -ENOMEM;
208 
209 	data->num_clusters = ARRAY_SIZE(tegra186_clusters);
210 
211 	bpmp = tegra_bpmp_get(&pdev->dev);
212 	if (IS_ERR(bpmp))
213 		return PTR_ERR(bpmp);
214 
215 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
216 	data->regs = devm_ioremap_resource(&pdev->dev, res);
217 	if (IS_ERR(data->regs)) {
218 		err = PTR_ERR(data->regs);
219 		goto put_bpmp;
220 	}
221 
222 	for (i = 0; i < data->num_clusters; i++) {
223 		struct tegra186_cpufreq_cluster *cluster = &data->clusters[i];
224 
225 		cluster->info = &tegra186_clusters[i];
226 		cluster->table = init_vhint_table(
227 			pdev, bpmp, cluster->info->bpmp_cluster_id);
228 		if (IS_ERR(cluster->table)) {
229 			err = PTR_ERR(cluster->table);
230 			goto put_bpmp;
231 		}
232 	}
233 
234 	tegra_bpmp_put(bpmp);
235 
236 	tegra186_cpufreq_driver.driver_data = data;
237 
238 	err = cpufreq_register_driver(&tegra186_cpufreq_driver);
239 	if (err)
240 		return err;
241 
242 	return 0;
243 
244 put_bpmp:
245 	tegra_bpmp_put(bpmp);
246 
247 	return err;
248 }
249 
250 static int tegra186_cpufreq_remove(struct platform_device *pdev)
251 {
252 	cpufreq_unregister_driver(&tegra186_cpufreq_driver);
253 
254 	return 0;
255 }
256 
257 static const struct of_device_id tegra186_cpufreq_of_match[] = {
258 	{ .compatible = "nvidia,tegra186-ccplex-cluster", },
259 	{ }
260 };
261 MODULE_DEVICE_TABLE(of, tegra186_cpufreq_of_match);
262 
263 static struct platform_driver tegra186_cpufreq_platform_driver = {
264 	.driver = {
265 		.name = "tegra186-cpufreq",
266 		.of_match_table = tegra186_cpufreq_of_match,
267 	},
268 	.probe = tegra186_cpufreq_probe,
269 	.remove = tegra186_cpufreq_remove,
270 };
271 module_platform_driver(tegra186_cpufreq_platform_driver);
272 
273 MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>");
274 MODULE_DESCRIPTION("NVIDIA Tegra186 cpufreq driver");
275 MODULE_LICENSE("GPL v2");
276