1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Marvell Armada AP CPU Clock Controller
4 *
5 * Copyright (C) 2018 Marvell
6 *
7 * Omri Itach <omrii@marvell.com>
8 * Gregory Clement <gregory.clement@bootlin.com>
9 */
10
11 #define pr_fmt(fmt) "ap-cpu-clk: " fmt
12
13 #include <linux/clk-provider.h>
14 #include <linux/clk.h>
15 #include <linux/mfd/syscon.h>
16 #include <linux/of.h>
17 #include <linux/of_address.h>
18 #include <linux/of_platform.h>
19 #include <linux/platform_device.h>
20 #include <linux/regmap.h>
21 #include "armada_ap_cp_helper.h"
22
23 #define AP806_CPU_CLUSTER0 0
24 #define AP806_CPU_CLUSTER1 1
25 #define AP806_CPUS_PER_CLUSTER 2
26 #define APN806_CPU1_MASK 0x1
27
28 #define APN806_CLUSTER_NUM_OFFSET 8
29 #define APN806_CLUSTER_NUM_MASK BIT(APN806_CLUSTER_NUM_OFFSET)
30
31 #define APN806_MAX_DIVIDER 32
32
33 /*
34 * struct cpu_dfs_regs: CPU DFS register mapping
35 * @divider_reg: full integer ratio from PLL frequency to CPU clock frequency
36 * @force_reg: request to force new ratio regardless of relation to other clocks
37 * @ratio_reg: central request to switch ratios
38 */
39 struct cpu_dfs_regs {
40 unsigned int divider_reg;
41 unsigned int force_reg;
42 unsigned int ratio_reg;
43 unsigned int ratio_state_reg;
44 unsigned int divider_mask;
45 unsigned int cluster_offset;
46 unsigned int force_mask;
47 int divider_offset;
48 int divider_ratio;
49 int ratio_offset;
50 int ratio_state_offset;
51 int ratio_state_cluster_offset;
52 };
53
54 /* AP806 CPU DFS register mapping*/
55 #define AP806_CA72MP2_0_PLL_CR_0_REG_OFFSET 0x278
56 #define AP806_CA72MP2_0_PLL_CR_1_REG_OFFSET 0x280
57 #define AP806_CA72MP2_0_PLL_CR_2_REG_OFFSET 0x284
58 #define AP806_CA72MP2_0_PLL_SR_REG_OFFSET 0xC94
59
60 #define AP806_CA72MP2_0_PLL_CR_CLUSTER_OFFSET 0x14
61 #define AP806_PLL_CR_0_CPU_CLK_DIV_RATIO_OFFSET 0
62 #define AP806_PLL_CR_CPU_CLK_DIV_RATIO 0
63 #define AP806_PLL_CR_0_CPU_CLK_DIV_RATIO_MASK \
64 (0x3f << AP806_PLL_CR_0_CPU_CLK_DIV_RATIO_OFFSET)
65 #define AP806_PLL_CR_0_CPU_CLK_RELOAD_FORCE_OFFSET 24
66 #define AP806_PLL_CR_0_CPU_CLK_RELOAD_FORCE_MASK \
67 (0x1 << AP806_PLL_CR_0_CPU_CLK_RELOAD_FORCE_OFFSET)
68 #define AP806_PLL_CR_0_CPU_CLK_RELOAD_RATIO_OFFSET 16
69 #define AP806_CA72MP2_0_PLL_RATIO_STABLE_OFFSET 0
70 #define AP806_CA72MP2_0_PLL_RATIO_STATE 11
71
72 #define STATUS_POLL_PERIOD_US 1
73 #define STATUS_POLL_TIMEOUT_US 1000000
74
75 #define to_ap_cpu_clk(_hw) container_of(_hw, struct ap_cpu_clk, hw)
76
77 static const struct cpu_dfs_regs ap806_dfs_regs = {
78 .divider_reg = AP806_CA72MP2_0_PLL_CR_0_REG_OFFSET,
79 .force_reg = AP806_CA72MP2_0_PLL_CR_1_REG_OFFSET,
80 .ratio_reg = AP806_CA72MP2_0_PLL_CR_2_REG_OFFSET,
81 .ratio_state_reg = AP806_CA72MP2_0_PLL_SR_REG_OFFSET,
82 .divider_mask = AP806_PLL_CR_0_CPU_CLK_DIV_RATIO_MASK,
83 .cluster_offset = AP806_CA72MP2_0_PLL_CR_CLUSTER_OFFSET,
84 .force_mask = AP806_PLL_CR_0_CPU_CLK_RELOAD_FORCE_MASK,
85 .divider_offset = AP806_PLL_CR_0_CPU_CLK_DIV_RATIO_OFFSET,
86 .divider_ratio = AP806_PLL_CR_CPU_CLK_DIV_RATIO,
87 .ratio_offset = AP806_PLL_CR_0_CPU_CLK_RELOAD_RATIO_OFFSET,
88 .ratio_state_offset = AP806_CA72MP2_0_PLL_RATIO_STABLE_OFFSET,
89 .ratio_state_cluster_offset = AP806_CA72MP2_0_PLL_RATIO_STABLE_OFFSET,
90 };
91
92 /* AP807 CPU DFS register mapping */
93 #define AP807_DEVICE_GENERAL_CONTROL_10_REG_OFFSET 0x278
94 #define AP807_DEVICE_GENERAL_CONTROL_11_REG_OFFSET 0x27c
95 #define AP807_DEVICE_GENERAL_STATUS_6_REG_OFFSET 0xc98
96 #define AP807_CA72MP2_0_PLL_CR_CLUSTER_OFFSET 0x8
97 #define AP807_PLL_CR_0_CPU_CLK_DIV_RATIO_OFFSET 18
98 #define AP807_PLL_CR_0_CPU_CLK_DIV_RATIO_MASK \
99 (0x3f << AP807_PLL_CR_0_CPU_CLK_DIV_RATIO_OFFSET)
100 #define AP807_PLL_CR_1_CPU_CLK_DIV_RATIO_OFFSET 12
101 #define AP807_PLL_CR_1_CPU_CLK_DIV_RATIO_MASK \
102 (0x3f << AP807_PLL_CR_1_CPU_CLK_DIV_RATIO_OFFSET)
103 #define AP807_PLL_CR_CPU_CLK_DIV_RATIO 3
104 #define AP807_PLL_CR_0_CPU_CLK_RELOAD_FORCE_OFFSET 0
105 #define AP807_PLL_CR_0_CPU_CLK_RELOAD_FORCE_MASK \
106 (0x3 << AP807_PLL_CR_0_CPU_CLK_RELOAD_FORCE_OFFSET)
107 #define AP807_PLL_CR_0_CPU_CLK_RELOAD_RATIO_OFFSET 6
108 #define AP807_CA72MP2_0_PLL_CLKDIV_RATIO_STABLE_OFFSET 20
109 #define AP807_CA72MP2_0_PLL_CLKDIV_RATIO_STABLE_CLUSTER_OFFSET 3
110
111 static const struct cpu_dfs_regs ap807_dfs_regs = {
112 .divider_reg = AP807_DEVICE_GENERAL_CONTROL_10_REG_OFFSET,
113 .force_reg = AP807_DEVICE_GENERAL_CONTROL_11_REG_OFFSET,
114 .ratio_reg = AP807_DEVICE_GENERAL_CONTROL_11_REG_OFFSET,
115 .ratio_state_reg = AP807_DEVICE_GENERAL_STATUS_6_REG_OFFSET,
116 .divider_mask = AP807_PLL_CR_0_CPU_CLK_DIV_RATIO_MASK,
117 .cluster_offset = AP807_CA72MP2_0_PLL_CR_CLUSTER_OFFSET,
118 .force_mask = AP807_PLL_CR_0_CPU_CLK_RELOAD_FORCE_MASK,
119 .divider_offset = AP807_PLL_CR_0_CPU_CLK_DIV_RATIO_OFFSET,
120 .divider_ratio = AP807_PLL_CR_CPU_CLK_DIV_RATIO,
121 .ratio_offset = AP807_PLL_CR_0_CPU_CLK_RELOAD_RATIO_OFFSET,
122 .ratio_state_offset = AP807_CA72MP2_0_PLL_CLKDIV_RATIO_STABLE_OFFSET,
123 .ratio_state_cluster_offset =
124 AP807_CA72MP2_0_PLL_CLKDIV_RATIO_STABLE_CLUSTER_OFFSET
125 };
126
127 /*
128 * struct ap806_clk: CPU cluster clock controller instance
129 * @cluster: Cluster clock controller index
130 * @clk_name: Cluster clock controller name
131 * @dev : Cluster clock device
132 * @hw: HW specific structure of Cluster clock controller
133 * @pll_cr_base: CA72MP2 Register base (Device Sample at Reset register)
134 */
135 struct ap_cpu_clk {
136 unsigned int cluster;
137 const char *clk_name;
138 struct device *dev;
139 struct clk_hw hw;
140 struct regmap *pll_cr_base;
141 const struct cpu_dfs_regs *pll_regs;
142 };
143
ap_cpu_clk_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)144 static unsigned long ap_cpu_clk_recalc_rate(struct clk_hw *hw,
145 unsigned long parent_rate)
146 {
147 struct ap_cpu_clk *clk = to_ap_cpu_clk(hw);
148 unsigned int cpu_clkdiv_reg;
149 int cpu_clkdiv_ratio;
150
151 cpu_clkdiv_reg = clk->pll_regs->divider_reg +
152 (clk->cluster * clk->pll_regs->cluster_offset);
153 regmap_read(clk->pll_cr_base, cpu_clkdiv_reg, &cpu_clkdiv_ratio);
154 cpu_clkdiv_ratio &= clk->pll_regs->divider_mask;
155 cpu_clkdiv_ratio >>= clk->pll_regs->divider_offset;
156
157 return parent_rate / cpu_clkdiv_ratio;
158 }
159
ap_cpu_clk_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)160 static int ap_cpu_clk_set_rate(struct clk_hw *hw, unsigned long rate,
161 unsigned long parent_rate)
162 {
163 struct ap_cpu_clk *clk = to_ap_cpu_clk(hw);
164 int ret, reg, divider = parent_rate / rate;
165 unsigned int cpu_clkdiv_reg, cpu_force_reg, cpu_ratio_reg, stable_bit;
166
167 cpu_clkdiv_reg = clk->pll_regs->divider_reg +
168 (clk->cluster * clk->pll_regs->cluster_offset);
169 cpu_force_reg = clk->pll_regs->force_reg +
170 (clk->cluster * clk->pll_regs->cluster_offset);
171 cpu_ratio_reg = clk->pll_regs->ratio_reg +
172 (clk->cluster * clk->pll_regs->cluster_offset);
173
174 regmap_read(clk->pll_cr_base, cpu_clkdiv_reg, ®);
175 reg &= ~(clk->pll_regs->divider_mask);
176 reg |= (divider << clk->pll_regs->divider_offset);
177
178 /*
179 * AP807 CPU divider has two channels with ratio 1:3 and divider_ratio
180 * is 1. Otherwise, in the case of the AP806, divider_ratio is 0.
181 */
182 if (clk->pll_regs->divider_ratio) {
183 reg &= ~(AP807_PLL_CR_1_CPU_CLK_DIV_RATIO_MASK);
184 reg |= ((divider * clk->pll_regs->divider_ratio) <<
185 AP807_PLL_CR_1_CPU_CLK_DIV_RATIO_OFFSET);
186 }
187 regmap_write(clk->pll_cr_base, cpu_clkdiv_reg, reg);
188
189
190 regmap_update_bits(clk->pll_cr_base, cpu_force_reg,
191 clk->pll_regs->force_mask,
192 clk->pll_regs->force_mask);
193
194 regmap_update_bits(clk->pll_cr_base, cpu_ratio_reg,
195 BIT(clk->pll_regs->ratio_offset),
196 BIT(clk->pll_regs->ratio_offset));
197
198 stable_bit = BIT(clk->pll_regs->ratio_state_offset +
199 clk->cluster *
200 clk->pll_regs->ratio_state_cluster_offset);
201 ret = regmap_read_poll_timeout(clk->pll_cr_base,
202 clk->pll_regs->ratio_state_reg, reg,
203 reg & stable_bit, STATUS_POLL_PERIOD_US,
204 STATUS_POLL_TIMEOUT_US);
205 if (ret)
206 return ret;
207
208 regmap_update_bits(clk->pll_cr_base, cpu_ratio_reg,
209 BIT(clk->pll_regs->ratio_offset), 0);
210
211 return 0;
212 }
213
ap_cpu_clk_round_rate(struct clk_hw * hw,unsigned long rate,unsigned long * parent_rate)214 static long ap_cpu_clk_round_rate(struct clk_hw *hw, unsigned long rate,
215 unsigned long *parent_rate)
216 {
217 int divider = *parent_rate / rate;
218
219 divider = min(divider, APN806_MAX_DIVIDER);
220
221 return *parent_rate / divider;
222 }
223
224 static const struct clk_ops ap_cpu_clk_ops = {
225 .recalc_rate = ap_cpu_clk_recalc_rate,
226 .round_rate = ap_cpu_clk_round_rate,
227 .set_rate = ap_cpu_clk_set_rate,
228 };
229
ap_cpu_clock_probe(struct platform_device * pdev)230 static int ap_cpu_clock_probe(struct platform_device *pdev)
231 {
232 int ret, nclusters = 0, cluster_index = 0;
233 struct device *dev = &pdev->dev;
234 struct device_node *dn, *np = dev->of_node;
235 struct clk_hw_onecell_data *ap_cpu_data;
236 struct ap_cpu_clk *ap_cpu_clk;
237 struct regmap *regmap;
238
239 regmap = syscon_node_to_regmap(np->parent);
240 if (IS_ERR(regmap)) {
241 pr_err("cannot get pll_cr_base regmap\n");
242 return PTR_ERR(regmap);
243 }
244
245 /*
246 * AP806 has 4 cpus and DFS for AP806 is controlled per
247 * cluster (2 CPUs per cluster), cpu0 and cpu1 are fixed to
248 * cluster0 while cpu2 and cpu3 are fixed to cluster1 whether
249 * they are enabled or not. Since cpu0 is the boot cpu, then
250 * cluster0 must exist. If cpu2 or cpu3 is enabled, cluster1
251 * will exist and the cluster number is 2; otherwise the
252 * cluster number is 1.
253 */
254 nclusters = 1;
255 for_each_of_cpu_node(dn) {
256 int cpu, err;
257
258 err = of_property_read_u32(dn, "reg", &cpu);
259 if (WARN_ON(err)) {
260 of_node_put(dn);
261 return err;
262 }
263
264 /* If cpu2 or cpu3 is enabled */
265 if (cpu & APN806_CLUSTER_NUM_MASK) {
266 nclusters = 2;
267 of_node_put(dn);
268 break;
269 }
270 }
271 /*
272 * DFS for AP806 is controlled per cluster (2 CPUs per cluster),
273 * so allocate structs per cluster
274 */
275 ap_cpu_clk = devm_kcalloc(dev, nclusters, sizeof(*ap_cpu_clk),
276 GFP_KERNEL);
277 if (!ap_cpu_clk)
278 return -ENOMEM;
279
280 ap_cpu_data = devm_kzalloc(dev, struct_size(ap_cpu_data, hws,
281 nclusters),
282 GFP_KERNEL);
283 if (!ap_cpu_data)
284 return -ENOMEM;
285
286 for_each_of_cpu_node(dn) {
287 char *clk_name = "cpu-cluster-0";
288 struct clk_init_data init;
289 const char *parent_name;
290 struct clk *parent;
291 int cpu, err;
292
293 err = of_property_read_u32(dn, "reg", &cpu);
294 if (WARN_ON(err)) {
295 of_node_put(dn);
296 return err;
297 }
298
299 cluster_index = cpu & APN806_CLUSTER_NUM_MASK;
300 cluster_index >>= APN806_CLUSTER_NUM_OFFSET;
301
302 /* Initialize once for one cluster */
303 if (ap_cpu_data->hws[cluster_index])
304 continue;
305
306 parent = of_clk_get(np, cluster_index);
307 if (IS_ERR(parent)) {
308 dev_err(dev, "Could not get the clock parent\n");
309 of_node_put(dn);
310 return -EINVAL;
311 }
312 parent_name = __clk_get_name(parent);
313 clk_name[12] += cluster_index;
314 ap_cpu_clk[cluster_index].clk_name =
315 ap_cp_unique_name(dev, np->parent, clk_name);
316 ap_cpu_clk[cluster_index].cluster = cluster_index;
317 ap_cpu_clk[cluster_index].pll_cr_base = regmap;
318 ap_cpu_clk[cluster_index].hw.init = &init;
319 ap_cpu_clk[cluster_index].dev = dev;
320 ap_cpu_clk[cluster_index].pll_regs = of_device_get_match_data(&pdev->dev);
321
322 init.name = ap_cpu_clk[cluster_index].clk_name;
323 init.ops = &ap_cpu_clk_ops;
324 init.num_parents = 1;
325 init.parent_names = &parent_name;
326
327 ret = devm_clk_hw_register(dev, &ap_cpu_clk[cluster_index].hw);
328 if (ret) {
329 of_node_put(dn);
330 return ret;
331 }
332 ap_cpu_data->hws[cluster_index] = &ap_cpu_clk[cluster_index].hw;
333 }
334
335 ap_cpu_data->num = cluster_index + 1;
336
337 ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, ap_cpu_data);
338 if (ret)
339 dev_err(dev, "failed to register OF clock provider\n");
340
341 return ret;
342 }
343
344 static const struct of_device_id ap_cpu_clock_of_match[] = {
345 {
346 .compatible = "marvell,ap806-cpu-clock",
347 .data = &ap806_dfs_regs,
348 },
349 {
350 .compatible = "marvell,ap807-cpu-clock",
351 .data = &ap807_dfs_regs,
352 },
353 { }
354 };
355
356 static struct platform_driver ap_cpu_clock_driver = {
357 .probe = ap_cpu_clock_probe,
358 .driver = {
359 .name = "marvell-ap-cpu-clock",
360 .of_match_table = ap_cpu_clock_of_match,
361 .suppress_bind_attrs = true,
362 },
363 };
364 builtin_platform_driver(ap_cpu_clock_driver);
365