xref: /openbmc/linux/drivers/clk/at91/pmc.c (revision be709d48)
1 /*
2  *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  */
10 
11 #include <linux/clk-provider.h>
12 #include <linux/clkdev.h>
13 #include <linux/clk/at91_pmc.h>
14 #include <linux/of.h>
15 #include <linux/mfd/syscon.h>
16 #include <linux/platform_device.h>
17 #include <linux/regmap.h>
18 #include <linux/syscore_ops.h>
19 
20 #include <asm/proc-fns.h>
21 
22 #include <dt-bindings/clock/at91.h>
23 
24 #include "pmc.h"
25 
26 #define PMC_MAX_IDS 128
27 #define PMC_MAX_PCKS 8
28 
29 int of_at91_get_clk_range(struct device_node *np, const char *propname,
30 			  struct clk_range *range)
31 {
32 	u32 min, max;
33 	int ret;
34 
35 	ret = of_property_read_u32_index(np, propname, 0, &min);
36 	if (ret)
37 		return ret;
38 
39 	ret = of_property_read_u32_index(np, propname, 1, &max);
40 	if (ret)
41 		return ret;
42 
43 	if (range) {
44 		range->min = min;
45 		range->max = max;
46 	}
47 
48 	return 0;
49 }
50 EXPORT_SYMBOL_GPL(of_at91_get_clk_range);
51 
52 struct clk_hw *of_clk_hw_pmc_get(struct of_phandle_args *clkspec, void *data)
53 {
54 	unsigned int type = clkspec->args[0];
55 	unsigned int idx = clkspec->args[1];
56 	struct pmc_data *pmc_data = data;
57 
58 	switch (type) {
59 	case PMC_TYPE_CORE:
60 		if (idx < pmc_data->ncore)
61 			return pmc_data->chws[idx];
62 		break;
63 	case PMC_TYPE_SYSTEM:
64 		if (idx < pmc_data->nsystem)
65 			return pmc_data->shws[idx];
66 		break;
67 	case PMC_TYPE_PERIPHERAL:
68 		if (idx < pmc_data->nperiph)
69 			return pmc_data->phws[idx];
70 		break;
71 	case PMC_TYPE_GCK:
72 		if (idx < pmc_data->ngck)
73 			return pmc_data->ghws[idx];
74 		break;
75 	default:
76 		break;
77 	}
78 
79 	pr_err("%s: invalid type (%u) or index (%u)\n", __func__, type, idx);
80 
81 	return ERR_PTR(-EINVAL);
82 }
83 
84 void pmc_data_free(struct pmc_data *pmc_data)
85 {
86 	kfree(pmc_data->chws);
87 	kfree(pmc_data->shws);
88 	kfree(pmc_data->phws);
89 	kfree(pmc_data->ghws);
90 }
91 
92 struct pmc_data *pmc_data_allocate(unsigned int ncore, unsigned int nsystem,
93 				   unsigned int nperiph, unsigned int ngck)
94 {
95 	struct pmc_data *pmc_data = kzalloc(sizeof(*pmc_data), GFP_KERNEL);
96 
97 	if (!pmc_data)
98 		return NULL;
99 
100 	pmc_data->ncore = ncore;
101 	pmc_data->chws = kcalloc(ncore, sizeof(struct clk_hw *), GFP_KERNEL);
102 	if (!pmc_data->chws)
103 		goto err;
104 
105 	pmc_data->nsystem = nsystem;
106 	pmc_data->shws = kcalloc(nsystem, sizeof(struct clk_hw *), GFP_KERNEL);
107 	if (!pmc_data->shws)
108 		goto err;
109 
110 	pmc_data->nperiph = nperiph;
111 	pmc_data->phws = kcalloc(nperiph, sizeof(struct clk_hw *), GFP_KERNEL);
112 	if (!pmc_data->phws)
113 		goto err;
114 
115 	pmc_data->ngck = ngck;
116 	pmc_data->ghws = kcalloc(ngck, sizeof(struct clk_hw *), GFP_KERNEL);
117 	if (!pmc_data->ghws)
118 		goto err;
119 
120 	return pmc_data;
121 
122 err:
123 	pmc_data_free(pmc_data);
124 
125 	return NULL;
126 }
127 
128 #ifdef CONFIG_PM
129 static struct regmap *pmcreg;
130 
131 static u8 registered_ids[PMC_MAX_IDS];
132 static u8 registered_pcks[PMC_MAX_PCKS];
133 
134 static struct
135 {
136 	u32 scsr;
137 	u32 pcsr0;
138 	u32 uckr;
139 	u32 mor;
140 	u32 mcfr;
141 	u32 pllar;
142 	u32 mckr;
143 	u32 usb;
144 	u32 imr;
145 	u32 pcsr1;
146 	u32 pcr[PMC_MAX_IDS];
147 	u32 audio_pll0;
148 	u32 audio_pll1;
149 	u32 pckr[PMC_MAX_PCKS];
150 } pmc_cache;
151 
152 /*
153  * As Peripheral ID 0 is invalid on AT91 chips, the identifier is stored
154  * without alteration in the table, and 0 is for unused clocks.
155  */
156 void pmc_register_id(u8 id)
157 {
158 	int i;
159 
160 	for (i = 0; i < PMC_MAX_IDS; i++) {
161 		if (registered_ids[i] == 0) {
162 			registered_ids[i] = id;
163 			break;
164 		}
165 		if (registered_ids[i] == id)
166 			break;
167 	}
168 }
169 
170 /*
171  * As Programmable Clock 0 is valid on AT91 chips, there is an offset
172  * of 1 between the stored value and the real clock ID.
173  */
174 void pmc_register_pck(u8 pck)
175 {
176 	int i;
177 
178 	for (i = 0; i < PMC_MAX_PCKS; i++) {
179 		if (registered_pcks[i] == 0) {
180 			registered_pcks[i] = pck + 1;
181 			break;
182 		}
183 		if (registered_pcks[i] == (pck + 1))
184 			break;
185 	}
186 }
187 
188 static int pmc_suspend(void)
189 {
190 	int i;
191 	u8 num;
192 
193 	regmap_read(pmcreg, AT91_PMC_SCSR, &pmc_cache.scsr);
194 	regmap_read(pmcreg, AT91_PMC_PCSR, &pmc_cache.pcsr0);
195 	regmap_read(pmcreg, AT91_CKGR_UCKR, &pmc_cache.uckr);
196 	regmap_read(pmcreg, AT91_CKGR_MOR, &pmc_cache.mor);
197 	regmap_read(pmcreg, AT91_CKGR_MCFR, &pmc_cache.mcfr);
198 	regmap_read(pmcreg, AT91_CKGR_PLLAR, &pmc_cache.pllar);
199 	regmap_read(pmcreg, AT91_PMC_MCKR, &pmc_cache.mckr);
200 	regmap_read(pmcreg, AT91_PMC_USB, &pmc_cache.usb);
201 	regmap_read(pmcreg, AT91_PMC_IMR, &pmc_cache.imr);
202 	regmap_read(pmcreg, AT91_PMC_PCSR1, &pmc_cache.pcsr1);
203 
204 	for (i = 0; registered_ids[i]; i++) {
205 		regmap_write(pmcreg, AT91_PMC_PCR,
206 			     (registered_ids[i] & AT91_PMC_PCR_PID_MASK));
207 		regmap_read(pmcreg, AT91_PMC_PCR,
208 			    &pmc_cache.pcr[registered_ids[i]]);
209 	}
210 	for (i = 0; registered_pcks[i]; i++) {
211 		num = registered_pcks[i] - 1;
212 		regmap_read(pmcreg, AT91_PMC_PCKR(num), &pmc_cache.pckr[num]);
213 	}
214 
215 	return 0;
216 }
217 
218 static bool pmc_ready(unsigned int mask)
219 {
220 	unsigned int status;
221 
222 	regmap_read(pmcreg, AT91_PMC_SR, &status);
223 
224 	return ((status & mask) == mask) ? 1 : 0;
225 }
226 
227 static void pmc_resume(void)
228 {
229 	int i;
230 	u8 num;
231 	u32 tmp;
232 	u32 mask = AT91_PMC_MCKRDY | AT91_PMC_LOCKA;
233 
234 	regmap_read(pmcreg, AT91_PMC_MCKR, &tmp);
235 	if (pmc_cache.mckr != tmp)
236 		pr_warn("MCKR was not configured properly by the firmware\n");
237 	regmap_read(pmcreg, AT91_CKGR_PLLAR, &tmp);
238 	if (pmc_cache.pllar != tmp)
239 		pr_warn("PLLAR was not configured properly by the firmware\n");
240 
241 	regmap_write(pmcreg, AT91_PMC_SCER, pmc_cache.scsr);
242 	regmap_write(pmcreg, AT91_PMC_PCER, pmc_cache.pcsr0);
243 	regmap_write(pmcreg, AT91_CKGR_UCKR, pmc_cache.uckr);
244 	regmap_write(pmcreg, AT91_CKGR_MOR, pmc_cache.mor);
245 	regmap_write(pmcreg, AT91_CKGR_MCFR, pmc_cache.mcfr);
246 	regmap_write(pmcreg, AT91_PMC_USB, pmc_cache.usb);
247 	regmap_write(pmcreg, AT91_PMC_IMR, pmc_cache.imr);
248 	regmap_write(pmcreg, AT91_PMC_PCER1, pmc_cache.pcsr1);
249 
250 	for (i = 0; registered_ids[i]; i++) {
251 		regmap_write(pmcreg, AT91_PMC_PCR,
252 			     pmc_cache.pcr[registered_ids[i]] |
253 			     AT91_PMC_PCR_CMD);
254 	}
255 	for (i = 0; registered_pcks[i]; i++) {
256 		num = registered_pcks[i] - 1;
257 		regmap_write(pmcreg, AT91_PMC_PCKR(num), pmc_cache.pckr[num]);
258 	}
259 
260 	if (pmc_cache.uckr & AT91_PMC_UPLLEN)
261 		mask |= AT91_PMC_LOCKU;
262 
263 	while (!pmc_ready(mask))
264 		cpu_relax();
265 }
266 
267 static struct syscore_ops pmc_syscore_ops = {
268 	.suspend = pmc_suspend,
269 	.resume = pmc_resume,
270 };
271 
272 static const struct of_device_id sama5d2_pmc_dt_ids[] = {
273 	{ .compatible = "atmel,sama5d2-pmc" },
274 	{ /* sentinel */ }
275 };
276 
277 static int __init pmc_register_ops(void)
278 {
279 	struct device_node *np;
280 
281 	np = of_find_matching_node(NULL, sama5d2_pmc_dt_ids);
282 
283 	pmcreg = syscon_node_to_regmap(np);
284 	if (IS_ERR(pmcreg))
285 		return PTR_ERR(pmcreg);
286 
287 	register_syscore_ops(&pmc_syscore_ops);
288 
289 	return 0;
290 }
291 /* This has to happen before arch_initcall because of the tcb_clksrc driver */
292 postcore_initcall(pmc_register_ops);
293 #endif
294