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 EDVD_CORE_VOLT_FREQ(core)		(0x20 + (core) * 0x4)
16 #define EDVD_CORE_VOLT_FREQ_F_SHIFT		0
17 #define EDVD_CORE_VOLT_FREQ_F_MASK		0xffff
18 #define EDVD_CORE_VOLT_FREQ_V_SHIFT		16
19 
20 struct tegra186_cpufreq_cluster_info {
21 	unsigned long offset;
22 	int cpus[4];
23 	unsigned int bpmp_cluster_id;
24 };
25 
26 #define NO_CPU -1
27 static const struct tegra186_cpufreq_cluster_info tegra186_clusters[] = {
28 	/* Denver cluster */
29 	{
30 		.offset = SZ_64K * 7,
31 		.cpus = { 1, 2, NO_CPU, NO_CPU },
32 		.bpmp_cluster_id = 0,
33 	},
34 	/* A57 cluster */
35 	{
36 		.offset = SZ_64K * 6,
37 		.cpus = { 0, 3, 4, 5 },
38 		.bpmp_cluster_id = 1,
39 	},
40 };
41 
42 struct tegra186_cpufreq_cluster {
43 	const struct tegra186_cpufreq_cluster_info *info;
44 	struct cpufreq_frequency_table *table;
45 	u32 ref_clk_khz;
46 	u32 div;
47 };
48 
49 struct tegra186_cpufreq_data {
50 	void __iomem *regs;
51 
52 	size_t num_clusters;
53 	struct tegra186_cpufreq_cluster *clusters;
54 };
55 
56 static int tegra186_cpufreq_init(struct cpufreq_policy *policy)
57 {
58 	struct tegra186_cpufreq_data *data = cpufreq_get_driver_data();
59 	unsigned int i;
60 
61 	for (i = 0; i < data->num_clusters; i++) {
62 		struct tegra186_cpufreq_cluster *cluster = &data->clusters[i];
63 		const struct tegra186_cpufreq_cluster_info *info =
64 			cluster->info;
65 		int core;
66 
67 		for (core = 0; core < ARRAY_SIZE(info->cpus); core++) {
68 			if (info->cpus[core] == policy->cpu)
69 				break;
70 		}
71 		if (core == ARRAY_SIZE(info->cpus))
72 			continue;
73 
74 		policy->driver_data =
75 			data->regs + info->offset + EDVD_CORE_VOLT_FREQ(core);
76 		policy->freq_table = cluster->table;
77 		break;
78 	}
79 
80 	policy->cpuinfo.transition_latency = 300 * 1000;
81 
82 	return 0;
83 }
84 
85 static int tegra186_cpufreq_set_target(struct cpufreq_policy *policy,
86 				       unsigned int index)
87 {
88 	struct cpufreq_frequency_table *tbl = policy->freq_table + index;
89 	void __iomem *edvd_reg = policy->driver_data;
90 	u32 edvd_val = tbl->driver_data;
91 
92 	writel(edvd_val, edvd_reg);
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 cpufreq_policy *policy;
101 	void __iomem *edvd_reg;
102 	unsigned int i, freq = 0;
103 	u32 ndiv;
104 
105 	policy = cpufreq_cpu_get(cpu);
106 	if (!policy)
107 		return 0;
108 
109 	edvd_reg = policy->driver_data;
110 	ndiv = readl(edvd_reg) & EDVD_CORE_VOLT_FREQ_F_MASK;
111 
112 	for (i = 0; i < data->num_clusters; i++) {
113 		struct tegra186_cpufreq_cluster *cluster = &data->clusters[i];
114 		int core;
115 
116 		for (core = 0; core < ARRAY_SIZE(cluster->info->cpus); core++) {
117 			if (cluster->info->cpus[core] != policy->cpu)
118 				continue;
119 
120 			freq = (cluster->ref_clk_khz * ndiv) / cluster->div;
121 			goto out;
122 		}
123 	}
124 
125 out:
126 	cpufreq_cpu_put(policy);
127 
128 	return freq;
129 }
130 
131 static struct cpufreq_driver tegra186_cpufreq_driver = {
132 	.name = "tegra186",
133 	.flags = CPUFREQ_STICKY | CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
134 			CPUFREQ_NEED_INITIAL_FREQ_CHECK,
135 	.get = tegra186_cpufreq_get,
136 	.verify = cpufreq_generic_frequency_table_verify,
137 	.target_index = tegra186_cpufreq_set_target,
138 	.init = tegra186_cpufreq_init,
139 	.attr = cpufreq_generic_attr,
140 };
141 
142 static struct cpufreq_frequency_table *init_vhint_table(
143 	struct platform_device *pdev, struct tegra_bpmp *bpmp,
144 	struct tegra186_cpufreq_cluster *cluster)
145 {
146 	struct cpufreq_frequency_table *table;
147 	struct mrq_cpu_vhint_request req;
148 	struct tegra_bpmp_message msg;
149 	struct cpu_vhint_data *data;
150 	int err, i, j, num_rates = 0;
151 	dma_addr_t phys;
152 	void *virt;
153 
154 	virt = dma_alloc_coherent(bpmp->dev, sizeof(*data), &phys,
155 				  GFP_KERNEL);
156 	if (!virt)
157 		return ERR_PTR(-ENOMEM);
158 
159 	data = (struct cpu_vhint_data *)virt;
160 
161 	memset(&req, 0, sizeof(req));
162 	req.addr = phys;
163 	req.cluster_id = cluster->info->bpmp_cluster_id;
164 
165 	memset(&msg, 0, sizeof(msg));
166 	msg.mrq = MRQ_CPU_VHINT;
167 	msg.tx.data = &req;
168 	msg.tx.size = sizeof(req);
169 
170 	err = tegra_bpmp_transfer(bpmp, &msg);
171 	if (err) {
172 		table = ERR_PTR(err);
173 		goto free;
174 	}
175 
176 	for (i = data->vfloor; i <= data->vceil; i++) {
177 		u16 ndiv = data->ndiv[i];
178 
179 		if (ndiv < data->ndiv_min || ndiv > data->ndiv_max)
180 			continue;
181 
182 		/* Only store lowest voltage index for each rate */
183 		if (i > 0 && ndiv == data->ndiv[i - 1])
184 			continue;
185 
186 		num_rates++;
187 	}
188 
189 	table = devm_kcalloc(&pdev->dev, num_rates + 1, sizeof(*table),
190 			     GFP_KERNEL);
191 	if (!table) {
192 		table = ERR_PTR(-ENOMEM);
193 		goto free;
194 	}
195 
196 	cluster->ref_clk_khz = data->ref_clk_hz / 1000;
197 	cluster->div = data->pdiv * data->mdiv;
198 
199 	for (i = data->vfloor, j = 0; i <= data->vceil; i++) {
200 		struct cpufreq_frequency_table *point;
201 		u16 ndiv = data->ndiv[i];
202 		u32 edvd_val = 0;
203 
204 		if (ndiv < data->ndiv_min || ndiv > data->ndiv_max)
205 			continue;
206 
207 		/* Only store lowest voltage index for each rate */
208 		if (i > 0 && ndiv == data->ndiv[i - 1])
209 			continue;
210 
211 		edvd_val |= i << EDVD_CORE_VOLT_FREQ_V_SHIFT;
212 		edvd_val |= ndiv << EDVD_CORE_VOLT_FREQ_F_SHIFT;
213 
214 		point = &table[j++];
215 		point->driver_data = edvd_val;
216 		point->frequency = (cluster->ref_clk_khz * ndiv) / cluster->div;
217 	}
218 
219 	table[j].frequency = CPUFREQ_TABLE_END;
220 
221 free:
222 	dma_free_coherent(bpmp->dev, sizeof(*data), virt, phys);
223 
224 	return table;
225 }
226 
227 static int tegra186_cpufreq_probe(struct platform_device *pdev)
228 {
229 	struct tegra186_cpufreq_data *data;
230 	struct tegra_bpmp *bpmp;
231 	unsigned int i = 0, err;
232 
233 	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
234 	if (!data)
235 		return -ENOMEM;
236 
237 	data->clusters = devm_kcalloc(&pdev->dev, ARRAY_SIZE(tegra186_clusters),
238 				      sizeof(*data->clusters), GFP_KERNEL);
239 	if (!data->clusters)
240 		return -ENOMEM;
241 
242 	data->num_clusters = ARRAY_SIZE(tegra186_clusters);
243 
244 	bpmp = tegra_bpmp_get(&pdev->dev);
245 	if (IS_ERR(bpmp))
246 		return PTR_ERR(bpmp);
247 
248 	data->regs = devm_platform_ioremap_resource(pdev, 0);
249 	if (IS_ERR(data->regs)) {
250 		err = PTR_ERR(data->regs);
251 		goto put_bpmp;
252 	}
253 
254 	for (i = 0; i < data->num_clusters; i++) {
255 		struct tegra186_cpufreq_cluster *cluster = &data->clusters[i];
256 
257 		cluster->info = &tegra186_clusters[i];
258 		cluster->table = init_vhint_table(pdev, bpmp, cluster);
259 		if (IS_ERR(cluster->table)) {
260 			err = PTR_ERR(cluster->table);
261 			goto put_bpmp;
262 		}
263 	}
264 
265 	tegra186_cpufreq_driver.driver_data = data;
266 
267 	err = cpufreq_register_driver(&tegra186_cpufreq_driver);
268 
269 put_bpmp:
270 	tegra_bpmp_put(bpmp);
271 
272 	return err;
273 }
274 
275 static int tegra186_cpufreq_remove(struct platform_device *pdev)
276 {
277 	cpufreq_unregister_driver(&tegra186_cpufreq_driver);
278 
279 	return 0;
280 }
281 
282 static const struct of_device_id tegra186_cpufreq_of_match[] = {
283 	{ .compatible = "nvidia,tegra186-ccplex-cluster", },
284 	{ }
285 };
286 MODULE_DEVICE_TABLE(of, tegra186_cpufreq_of_match);
287 
288 static struct platform_driver tegra186_cpufreq_platform_driver = {
289 	.driver = {
290 		.name = "tegra186-cpufreq",
291 		.of_match_table = tegra186_cpufreq_of_match,
292 	},
293 	.probe = tegra186_cpufreq_probe,
294 	.remove = tegra186_cpufreq_remove,
295 };
296 module_platform_driver(tegra186_cpufreq_platform_driver);
297 
298 MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>");
299 MODULE_DESCRIPTION("NVIDIA Tegra186 cpufreq driver");
300 MODULE_LICENSE("GPL v2");
301