xref: /openbmc/linux/drivers/clk/mvebu/ap-cpu-clk.c (revision 20e2fc42)
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 
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 
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, &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 
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 
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 			return err;
261 
262 		/* If cpu2 or cpu3 is enabled */
263 		if (cpu & APN806_CLUSTER_NUM_MASK) {
264 			nclusters = 2;
265 			break;
266 		}
267 	}
268 	/*
269 	 * DFS for AP806 is controlled per cluster (2 CPUs per cluster),
270 	 * so allocate structs per cluster
271 	 */
272 	ap_cpu_clk = devm_kcalloc(dev, nclusters, sizeof(*ap_cpu_clk),
273 				  GFP_KERNEL);
274 	if (!ap_cpu_clk)
275 		return -ENOMEM;
276 
277 	ap_cpu_data = devm_kzalloc(dev, sizeof(*ap_cpu_data) +
278 				sizeof(struct clk_hw *) * nclusters,
279 				GFP_KERNEL);
280 	if (!ap_cpu_data)
281 		return -ENOMEM;
282 
283 	for_each_of_cpu_node(dn) {
284 		char *clk_name = "cpu-cluster-0";
285 		struct clk_init_data init;
286 		const char *parent_name;
287 		struct clk *parent;
288 		int cpu, err;
289 
290 		err = of_property_read_u32(dn, "reg", &cpu);
291 		if (WARN_ON(err))
292 			return err;
293 
294 		cluster_index = cpu & APN806_CLUSTER_NUM_MASK;
295 		cluster_index >>= APN806_CLUSTER_NUM_OFFSET;
296 
297 		/* Initialize once for one cluster */
298 		if (ap_cpu_data->hws[cluster_index])
299 			continue;
300 
301 		parent = of_clk_get(np, cluster_index);
302 		if (IS_ERR(parent)) {
303 			dev_err(dev, "Could not get the clock parent\n");
304 			return -EINVAL;
305 		}
306 		parent_name =  __clk_get_name(parent);
307 		clk_name[12] += cluster_index;
308 		ap_cpu_clk[cluster_index].clk_name =
309 			ap_cp_unique_name(dev, np->parent, clk_name);
310 		ap_cpu_clk[cluster_index].cluster = cluster_index;
311 		ap_cpu_clk[cluster_index].pll_cr_base = regmap;
312 		ap_cpu_clk[cluster_index].hw.init = &init;
313 		ap_cpu_clk[cluster_index].dev = dev;
314 		ap_cpu_clk[cluster_index].pll_regs = of_device_get_match_data(&pdev->dev);
315 
316 		init.name = ap_cpu_clk[cluster_index].clk_name;
317 		init.ops = &ap_cpu_clk_ops;
318 		init.num_parents = 1;
319 		init.parent_names = &parent_name;
320 
321 		ret = devm_clk_hw_register(dev, &ap_cpu_clk[cluster_index].hw);
322 		if (ret)
323 			return ret;
324 		ap_cpu_data->hws[cluster_index] = &ap_cpu_clk[cluster_index].hw;
325 	}
326 
327 	ap_cpu_data->num = cluster_index + 1;
328 
329 	ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, ap_cpu_data);
330 	if (ret)
331 		dev_err(dev, "failed to register OF clock provider\n");
332 
333 	return ret;
334 }
335 
336 static const struct of_device_id ap_cpu_clock_of_match[] = {
337 	{
338 		.compatible = "marvell,ap806-cpu-clock",
339 		.data = &ap806_dfs_regs,
340 	},
341 	{
342 		.compatible = "marvell,ap807-cpu-clock",
343 		.data = &ap807_dfs_regs,
344 	},
345 	{ }
346 };
347 
348 static struct platform_driver ap_cpu_clock_driver = {
349 	.probe = ap_cpu_clock_probe,
350 	.driver		= {
351 		.name	= "marvell-ap-cpu-clock",
352 		.of_match_table = ap_cpu_clock_of_match,
353 		.suppress_bind_attrs = true,
354 	},
355 };
356 builtin_platform_driver(ap_cpu_clock_driver);
357