xref: /openbmc/linux/drivers/clk/at91/pmc.c (revision e218325f)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
4  */
5 
6 #include <linux/clk-provider.h>
7 #include <linux/clkdev.h>
8 #include <linux/clk/at91_pmc.h>
9 #include <linux/of.h>
10 #include <linux/mfd/syscon.h>
11 #include <linux/platform_device.h>
12 #include <linux/regmap.h>
13 #include <linux/syscore_ops.h>
14 
15 #include <asm/proc-fns.h>
16 
17 #include <dt-bindings/clock/at91.h>
18 
19 #include "pmc.h"
20 
21 #define PMC_MAX_IDS 128
22 #define PMC_MAX_PCKS 8
23 
24 int of_at91_get_clk_range(struct device_node *np, const char *propname,
25 			  struct clk_range *range)
26 {
27 	u32 min, max;
28 	int ret;
29 
30 	ret = of_property_read_u32_index(np, propname, 0, &min);
31 	if (ret)
32 		return ret;
33 
34 	ret = of_property_read_u32_index(np, propname, 1, &max);
35 	if (ret)
36 		return ret;
37 
38 	if (range) {
39 		range->min = min;
40 		range->max = max;
41 	}
42 
43 	return 0;
44 }
45 EXPORT_SYMBOL_GPL(of_at91_get_clk_range);
46 
47 struct clk_hw *of_clk_hw_pmc_get(struct of_phandle_args *clkspec, void *data)
48 {
49 	unsigned int type = clkspec->args[0];
50 	unsigned int idx = clkspec->args[1];
51 	struct pmc_data *pmc_data = data;
52 
53 	switch (type) {
54 	case PMC_TYPE_CORE:
55 		if (idx < pmc_data->ncore)
56 			return pmc_data->chws[idx];
57 		break;
58 	case PMC_TYPE_SYSTEM:
59 		if (idx < pmc_data->nsystem)
60 			return pmc_data->shws[idx];
61 		break;
62 	case PMC_TYPE_PERIPHERAL:
63 		if (idx < pmc_data->nperiph)
64 			return pmc_data->phws[idx];
65 		break;
66 	case PMC_TYPE_GCK:
67 		if (idx < pmc_data->ngck)
68 			return pmc_data->ghws[idx];
69 		break;
70 	default:
71 		break;
72 	}
73 
74 	pr_err("%s: invalid type (%u) or index (%u)\n", __func__, type, idx);
75 
76 	return ERR_PTR(-EINVAL);
77 }
78 
79 void pmc_data_free(struct pmc_data *pmc_data)
80 {
81 	kfree(pmc_data->chws);
82 	kfree(pmc_data->shws);
83 	kfree(pmc_data->phws);
84 	kfree(pmc_data->ghws);
85 }
86 
87 struct pmc_data *pmc_data_allocate(unsigned int ncore, unsigned int nsystem,
88 				   unsigned int nperiph, unsigned int ngck)
89 {
90 	struct pmc_data *pmc_data = kzalloc(sizeof(*pmc_data), GFP_KERNEL);
91 
92 	if (!pmc_data)
93 		return NULL;
94 
95 	pmc_data->ncore = ncore;
96 	pmc_data->chws = kcalloc(ncore, sizeof(struct clk_hw *), GFP_KERNEL);
97 	if (!pmc_data->chws)
98 		goto err;
99 
100 	pmc_data->nsystem = nsystem;
101 	pmc_data->shws = kcalloc(nsystem, sizeof(struct clk_hw *), GFP_KERNEL);
102 	if (!pmc_data->shws)
103 		goto err;
104 
105 	pmc_data->nperiph = nperiph;
106 	pmc_data->phws = kcalloc(nperiph, sizeof(struct clk_hw *), GFP_KERNEL);
107 	if (!pmc_data->phws)
108 		goto err;
109 
110 	pmc_data->ngck = ngck;
111 	pmc_data->ghws = kcalloc(ngck, sizeof(struct clk_hw *), GFP_KERNEL);
112 	if (!pmc_data->ghws)
113 		goto err;
114 
115 	return pmc_data;
116 
117 err:
118 	pmc_data_free(pmc_data);
119 
120 	return NULL;
121 }
122 
123 #ifdef CONFIG_PM
124 static struct regmap *pmcreg;
125 
126 static u8 registered_ids[PMC_MAX_IDS];
127 static u8 registered_pcks[PMC_MAX_PCKS];
128 
129 static struct
130 {
131 	u32 scsr;
132 	u32 pcsr0;
133 	u32 uckr;
134 	u32 mor;
135 	u32 mcfr;
136 	u32 pllar;
137 	u32 mckr;
138 	u32 usb;
139 	u32 imr;
140 	u32 pcsr1;
141 	u32 pcr[PMC_MAX_IDS];
142 	u32 audio_pll0;
143 	u32 audio_pll1;
144 	u32 pckr[PMC_MAX_PCKS];
145 } pmc_cache;
146 
147 /*
148  * As Peripheral ID 0 is invalid on AT91 chips, the identifier is stored
149  * without alteration in the table, and 0 is for unused clocks.
150  */
151 void pmc_register_id(u8 id)
152 {
153 	int i;
154 
155 	for (i = 0; i < PMC_MAX_IDS; i++) {
156 		if (registered_ids[i] == 0) {
157 			registered_ids[i] = id;
158 			break;
159 		}
160 		if (registered_ids[i] == id)
161 			break;
162 	}
163 }
164 
165 /*
166  * As Programmable Clock 0 is valid on AT91 chips, there is an offset
167  * of 1 between the stored value and the real clock ID.
168  */
169 void pmc_register_pck(u8 pck)
170 {
171 	int i;
172 
173 	for (i = 0; i < PMC_MAX_PCKS; i++) {
174 		if (registered_pcks[i] == 0) {
175 			registered_pcks[i] = pck + 1;
176 			break;
177 		}
178 		if (registered_pcks[i] == (pck + 1))
179 			break;
180 	}
181 }
182 
183 static int pmc_suspend(void)
184 {
185 	int i;
186 	u8 num;
187 
188 	regmap_read(pmcreg, AT91_PMC_SCSR, &pmc_cache.scsr);
189 	regmap_read(pmcreg, AT91_PMC_PCSR, &pmc_cache.pcsr0);
190 	regmap_read(pmcreg, AT91_CKGR_UCKR, &pmc_cache.uckr);
191 	regmap_read(pmcreg, AT91_CKGR_MOR, &pmc_cache.mor);
192 	regmap_read(pmcreg, AT91_CKGR_MCFR, &pmc_cache.mcfr);
193 	regmap_read(pmcreg, AT91_CKGR_PLLAR, &pmc_cache.pllar);
194 	regmap_read(pmcreg, AT91_PMC_MCKR, &pmc_cache.mckr);
195 	regmap_read(pmcreg, AT91_PMC_USB, &pmc_cache.usb);
196 	regmap_read(pmcreg, AT91_PMC_IMR, &pmc_cache.imr);
197 	regmap_read(pmcreg, AT91_PMC_PCSR1, &pmc_cache.pcsr1);
198 
199 	for (i = 0; registered_ids[i]; i++) {
200 		regmap_write(pmcreg, AT91_PMC_PCR,
201 			     (registered_ids[i] & AT91_PMC_PCR_PID_MASK));
202 		regmap_read(pmcreg, AT91_PMC_PCR,
203 			    &pmc_cache.pcr[registered_ids[i]]);
204 	}
205 	for (i = 0; registered_pcks[i]; i++) {
206 		num = registered_pcks[i] - 1;
207 		regmap_read(pmcreg, AT91_PMC_PCKR(num), &pmc_cache.pckr[num]);
208 	}
209 
210 	return 0;
211 }
212 
213 static bool pmc_ready(unsigned int mask)
214 {
215 	unsigned int status;
216 
217 	regmap_read(pmcreg, AT91_PMC_SR, &status);
218 
219 	return ((status & mask) == mask) ? 1 : 0;
220 }
221 
222 static void pmc_resume(void)
223 {
224 	int i;
225 	u8 num;
226 	u32 tmp;
227 	u32 mask = AT91_PMC_MCKRDY | AT91_PMC_LOCKA;
228 
229 	regmap_read(pmcreg, AT91_PMC_MCKR, &tmp);
230 	if (pmc_cache.mckr != tmp)
231 		pr_warn("MCKR was not configured properly by the firmware\n");
232 	regmap_read(pmcreg, AT91_CKGR_PLLAR, &tmp);
233 	if (pmc_cache.pllar != tmp)
234 		pr_warn("PLLAR was not configured properly by the firmware\n");
235 
236 	regmap_write(pmcreg, AT91_PMC_SCER, pmc_cache.scsr);
237 	regmap_write(pmcreg, AT91_PMC_PCER, pmc_cache.pcsr0);
238 	regmap_write(pmcreg, AT91_CKGR_UCKR, pmc_cache.uckr);
239 	regmap_write(pmcreg, AT91_CKGR_MOR, pmc_cache.mor);
240 	regmap_write(pmcreg, AT91_CKGR_MCFR, pmc_cache.mcfr);
241 	regmap_write(pmcreg, AT91_PMC_USB, pmc_cache.usb);
242 	regmap_write(pmcreg, AT91_PMC_IMR, pmc_cache.imr);
243 	regmap_write(pmcreg, AT91_PMC_PCER1, pmc_cache.pcsr1);
244 
245 	for (i = 0; registered_ids[i]; i++) {
246 		regmap_write(pmcreg, AT91_PMC_PCR,
247 			     pmc_cache.pcr[registered_ids[i]] |
248 			     AT91_PMC_PCR_CMD);
249 	}
250 	for (i = 0; registered_pcks[i]; i++) {
251 		num = registered_pcks[i] - 1;
252 		regmap_write(pmcreg, AT91_PMC_PCKR(num), pmc_cache.pckr[num]);
253 	}
254 
255 	if (pmc_cache.uckr & AT91_PMC_UPLLEN)
256 		mask |= AT91_PMC_LOCKU;
257 
258 	while (!pmc_ready(mask))
259 		cpu_relax();
260 }
261 
262 static struct syscore_ops pmc_syscore_ops = {
263 	.suspend = pmc_suspend,
264 	.resume = pmc_resume,
265 };
266 
267 static const struct of_device_id sama5d2_pmc_dt_ids[] = {
268 	{ .compatible = "atmel,sama5d2-pmc" },
269 	{ /* sentinel */ }
270 };
271 
272 static int __init pmc_register_ops(void)
273 {
274 	struct device_node *np;
275 
276 	np = of_find_matching_node(NULL, sama5d2_pmc_dt_ids);
277 	if (!np)
278 		return -ENODEV;
279 
280 	pmcreg = device_node_to_regmap(np);
281 	of_node_put(np);
282 	if (IS_ERR(pmcreg))
283 		return PTR_ERR(pmcreg);
284 
285 	register_syscore_ops(&pmc_syscore_ops);
286 
287 	return 0;
288 }
289 /* This has to happen before arch_initcall because of the tcb_clksrc driver */
290 postcore_initcall(pmc_register_ops);
291 #endif
292