xref: /openbmc/linux/drivers/clk/rockchip/clk.c (revision abfbd895)
1 /*
2  * Copyright (c) 2014 MundoReader S.L.
3  * Author: Heiko Stuebner <heiko@sntech.de>
4  *
5  * based on
6  *
7  * samsung/clk.c
8  * Copyright (c) 2013 Samsung Electronics Co., Ltd.
9  * Copyright (c) 2013 Linaro Ltd.
10  * Author: Thomas Abraham <thomas.ab@samsung.com>
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  */
22 
23 #include <linux/slab.h>
24 #include <linux/clk.h>
25 #include <linux/clk-provider.h>
26 #include <linux/mfd/syscon.h>
27 #include <linux/regmap.h>
28 #include <linux/reboot.h>
29 #include "clk.h"
30 
31 /**
32  * Register a clock branch.
33  * Most clock branches have a form like
34  *
35  * src1 --|--\
36  *        |M |--[GATE]-[DIV]-
37  * src2 --|--/
38  *
39  * sometimes without one of those components.
40  */
41 static struct clk *rockchip_clk_register_branch(const char *name,
42 		const char *const *parent_names, u8 num_parents, void __iomem *base,
43 		int muxdiv_offset, u8 mux_shift, u8 mux_width, u8 mux_flags,
44 		u8 div_shift, u8 div_width, u8 div_flags,
45 		struct clk_div_table *div_table, int gate_offset,
46 		u8 gate_shift, u8 gate_flags, unsigned long flags,
47 		spinlock_t *lock)
48 {
49 	struct clk *clk;
50 	struct clk_mux *mux = NULL;
51 	struct clk_gate *gate = NULL;
52 	struct clk_divider *div = NULL;
53 	const struct clk_ops *mux_ops = NULL, *div_ops = NULL,
54 			     *gate_ops = NULL;
55 
56 	if (num_parents > 1) {
57 		mux = kzalloc(sizeof(*mux), GFP_KERNEL);
58 		if (!mux)
59 			return ERR_PTR(-ENOMEM);
60 
61 		mux->reg = base + muxdiv_offset;
62 		mux->shift = mux_shift;
63 		mux->mask = BIT(mux_width) - 1;
64 		mux->flags = mux_flags;
65 		mux->lock = lock;
66 		mux_ops = (mux_flags & CLK_MUX_READ_ONLY) ? &clk_mux_ro_ops
67 							: &clk_mux_ops;
68 	}
69 
70 	if (gate_offset >= 0) {
71 		gate = kzalloc(sizeof(*gate), GFP_KERNEL);
72 		if (!gate)
73 			return ERR_PTR(-ENOMEM);
74 
75 		gate->flags = gate_flags;
76 		gate->reg = base + gate_offset;
77 		gate->bit_idx = gate_shift;
78 		gate->lock = lock;
79 		gate_ops = &clk_gate_ops;
80 	}
81 
82 	if (div_width > 0) {
83 		div = kzalloc(sizeof(*div), GFP_KERNEL);
84 		if (!div)
85 			return ERR_PTR(-ENOMEM);
86 
87 		div->flags = div_flags;
88 		div->reg = base + muxdiv_offset;
89 		div->shift = div_shift;
90 		div->width = div_width;
91 		div->lock = lock;
92 		div->table = div_table;
93 		div_ops = &clk_divider_ops;
94 	}
95 
96 	clk = clk_register_composite(NULL, name, parent_names, num_parents,
97 				     mux ? &mux->hw : NULL, mux_ops,
98 				     div ? &div->hw : NULL, div_ops,
99 				     gate ? &gate->hw : NULL, gate_ops,
100 				     flags);
101 
102 	return clk;
103 }
104 
105 static struct clk *rockchip_clk_register_frac_branch(const char *name,
106 		const char *const *parent_names, u8 num_parents,
107 		void __iomem *base, int muxdiv_offset, u8 div_flags,
108 		int gate_offset, u8 gate_shift, u8 gate_flags,
109 		unsigned long flags, spinlock_t *lock)
110 {
111 	struct clk *clk;
112 	struct clk_gate *gate = NULL;
113 	struct clk_fractional_divider *div = NULL;
114 	const struct clk_ops *div_ops = NULL, *gate_ops = NULL;
115 
116 	if (gate_offset >= 0) {
117 		gate = kzalloc(sizeof(*gate), GFP_KERNEL);
118 		if (!gate)
119 			return ERR_PTR(-ENOMEM);
120 
121 		gate->flags = gate_flags;
122 		gate->reg = base + gate_offset;
123 		gate->bit_idx = gate_shift;
124 		gate->lock = lock;
125 		gate_ops = &clk_gate_ops;
126 	}
127 
128 	if (muxdiv_offset < 0)
129 		return ERR_PTR(-EINVAL);
130 
131 	div = kzalloc(sizeof(*div), GFP_KERNEL);
132 	if (!div)
133 		return ERR_PTR(-ENOMEM);
134 
135 	div->flags = div_flags;
136 	div->reg = base + muxdiv_offset;
137 	div->mshift = 16;
138 	div->mwidth = 16;
139 	div->mmask = GENMASK(div->mwidth - 1, 0) << div->mshift;
140 	div->nshift = 0;
141 	div->nwidth = 16;
142 	div->nmask = GENMASK(div->nwidth - 1, 0) << div->nshift;
143 	div->lock = lock;
144 	div_ops = &clk_fractional_divider_ops;
145 
146 	clk = clk_register_composite(NULL, name, parent_names, num_parents,
147 				     NULL, NULL,
148 				     &div->hw, div_ops,
149 				     gate ? &gate->hw : NULL, gate_ops,
150 				     flags);
151 
152 	return clk;
153 }
154 
155 static DEFINE_SPINLOCK(clk_lock);
156 static struct clk **clk_table;
157 static void __iomem *reg_base;
158 static struct clk_onecell_data clk_data;
159 static struct device_node *cru_node;
160 static struct regmap *grf;
161 
162 void __init rockchip_clk_init(struct device_node *np, void __iomem *base,
163 			      unsigned long nr_clks)
164 {
165 	reg_base = base;
166 	cru_node = np;
167 	grf = ERR_PTR(-EPROBE_DEFER);
168 
169 	clk_table = kcalloc(nr_clks, sizeof(struct clk *), GFP_KERNEL);
170 	if (!clk_table)
171 		pr_err("%s: could not allocate clock lookup table\n", __func__);
172 
173 	clk_data.clks = clk_table;
174 	clk_data.clk_num = nr_clks;
175 	of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
176 }
177 
178 struct regmap *rockchip_clk_get_grf(void)
179 {
180 	if (IS_ERR(grf))
181 		grf = syscon_regmap_lookup_by_phandle(cru_node, "rockchip,grf");
182 	return grf;
183 }
184 
185 void rockchip_clk_add_lookup(struct clk *clk, unsigned int id)
186 {
187 	if (clk_table && id)
188 		clk_table[id] = clk;
189 }
190 
191 void __init rockchip_clk_register_plls(struct rockchip_pll_clock *list,
192 				unsigned int nr_pll, int grf_lock_offset)
193 {
194 	struct clk *clk;
195 	int idx;
196 
197 	for (idx = 0; idx < nr_pll; idx++, list++) {
198 		clk = rockchip_clk_register_pll(list->type, list->name,
199 				list->parent_names, list->num_parents,
200 				reg_base, list->con_offset, grf_lock_offset,
201 				list->lock_shift, list->mode_offset,
202 				list->mode_shift, list->rate_table,
203 				list->pll_flags, &clk_lock);
204 		if (IS_ERR(clk)) {
205 			pr_err("%s: failed to register clock %s\n", __func__,
206 				list->name);
207 			continue;
208 		}
209 
210 		rockchip_clk_add_lookup(clk, list->id);
211 	}
212 }
213 
214 void __init rockchip_clk_register_branches(
215 				      struct rockchip_clk_branch *list,
216 				      unsigned int nr_clk)
217 {
218 	struct clk *clk = NULL;
219 	unsigned int idx;
220 	unsigned long flags;
221 
222 	for (idx = 0; idx < nr_clk; idx++, list++) {
223 		flags = list->flags;
224 
225 		/* catch simple muxes */
226 		switch (list->branch_type) {
227 		case branch_mux:
228 			clk = clk_register_mux(NULL, list->name,
229 				list->parent_names, list->num_parents,
230 				flags, reg_base + list->muxdiv_offset,
231 				list->mux_shift, list->mux_width,
232 				list->mux_flags, &clk_lock);
233 			break;
234 		case branch_divider:
235 			if (list->div_table)
236 				clk = clk_register_divider_table(NULL,
237 					list->name, list->parent_names[0],
238 					flags, reg_base + list->muxdiv_offset,
239 					list->div_shift, list->div_width,
240 					list->div_flags, list->div_table,
241 					&clk_lock);
242 			else
243 				clk = clk_register_divider(NULL, list->name,
244 					list->parent_names[0], flags,
245 					reg_base + list->muxdiv_offset,
246 					list->div_shift, list->div_width,
247 					list->div_flags, &clk_lock);
248 			break;
249 		case branch_fraction_divider:
250 			clk = rockchip_clk_register_frac_branch(list->name,
251 				list->parent_names, list->num_parents,
252 				reg_base, list->muxdiv_offset, list->div_flags,
253 				list->gate_offset, list->gate_shift,
254 				list->gate_flags, flags, &clk_lock);
255 			break;
256 		case branch_gate:
257 			flags |= CLK_SET_RATE_PARENT;
258 
259 			clk = clk_register_gate(NULL, list->name,
260 				list->parent_names[0], flags,
261 				reg_base + list->gate_offset,
262 				list->gate_shift, list->gate_flags, &clk_lock);
263 			break;
264 		case branch_composite:
265 			clk = rockchip_clk_register_branch(list->name,
266 				list->parent_names, list->num_parents,
267 				reg_base, list->muxdiv_offset, list->mux_shift,
268 				list->mux_width, list->mux_flags,
269 				list->div_shift, list->div_width,
270 				list->div_flags, list->div_table,
271 				list->gate_offset, list->gate_shift,
272 				list->gate_flags, flags, &clk_lock);
273 			break;
274 		case branch_mmc:
275 			clk = rockchip_clk_register_mmc(
276 				list->name,
277 				list->parent_names, list->num_parents,
278 				reg_base + list->muxdiv_offset,
279 				list->div_shift
280 			);
281 			break;
282 		case branch_inverter:
283 			clk = rockchip_clk_register_inverter(
284 				list->name, list->parent_names,
285 				list->num_parents,
286 				reg_base + list->muxdiv_offset,
287 				list->div_shift, list->div_flags, &clk_lock);
288 			break;
289 		}
290 
291 		/* none of the cases above matched */
292 		if (!clk) {
293 			pr_err("%s: unknown clock type %d\n",
294 			       __func__, list->branch_type);
295 			continue;
296 		}
297 
298 		if (IS_ERR(clk)) {
299 			pr_err("%s: failed to register clock %s: %ld\n",
300 			       __func__, list->name, PTR_ERR(clk));
301 			continue;
302 		}
303 
304 		rockchip_clk_add_lookup(clk, list->id);
305 	}
306 }
307 
308 void __init rockchip_clk_register_armclk(unsigned int lookup_id,
309 			const char *name, const char *const *parent_names,
310 			u8 num_parents,
311 			const struct rockchip_cpuclk_reg_data *reg_data,
312 			const struct rockchip_cpuclk_rate_table *rates,
313 			int nrates)
314 {
315 	struct clk *clk;
316 
317 	clk = rockchip_clk_register_cpuclk(name, parent_names, num_parents,
318 					   reg_data, rates, nrates, reg_base,
319 					   &clk_lock);
320 	if (IS_ERR(clk)) {
321 		pr_err("%s: failed to register clock %s: %ld\n",
322 		       __func__, name, PTR_ERR(clk));
323 		return;
324 	}
325 
326 	rockchip_clk_add_lookup(clk, lookup_id);
327 }
328 
329 void __init rockchip_clk_protect_critical(const char *const clocks[],
330 					  int nclocks)
331 {
332 	int i;
333 
334 	/* Protect the clocks that needs to stay on */
335 	for (i = 0; i < nclocks; i++) {
336 		struct clk *clk = __clk_lookup(clocks[i]);
337 
338 		if (clk)
339 			clk_prepare_enable(clk);
340 	}
341 }
342 
343 static unsigned int reg_restart;
344 static int rockchip_restart_notify(struct notifier_block *this,
345 				   unsigned long mode, void *cmd)
346 {
347 	writel(0xfdb9, reg_base + reg_restart);
348 	return NOTIFY_DONE;
349 }
350 
351 static struct notifier_block rockchip_restart_handler = {
352 	.notifier_call = rockchip_restart_notify,
353 	.priority = 128,
354 };
355 
356 void __init rockchip_register_restart_notifier(unsigned int reg)
357 {
358 	int ret;
359 
360 	reg_restart = reg;
361 	ret = register_restart_handler(&rockchip_restart_handler);
362 	if (ret)
363 		pr_err("%s: cannot register restart handler, %d\n",
364 		       __func__, ret);
365 }
366