1 /*
2 * rcar_gen2 Core CPG Clocks
3 *
4 * Copyright (C) 2013 Ideas On Board SPRL
5 *
6 * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; version 2 of the License.
11 */
12
13 #include <linux/clk-provider.h>
14 #include <linux/clk/shmobile.h>
15 #include <linux/init.h>
16 #include <linux/kernel.h>
17 #include <linux/math64.h>
18 #include <linux/of.h>
19 #include <linux/of_address.h>
20 #include <linux/slab.h>
21 #include <linux/spinlock.h>
22
23 struct rcar_gen2_cpg {
24 struct clk_onecell_data data;
25 spinlock_t lock;
26 void __iomem *reg;
27 };
28
29 #define CPG_FRQCRB 0x00000004
30 #define CPG_FRQCRB_KICK BIT(31)
31 #define CPG_SDCKCR 0x00000074
32 #define CPG_PLL0CR 0x000000d8
33 #define CPG_FRQCRC 0x000000e0
34 #define CPG_FRQCRC_ZFC_MASK (0x1f << 8)
35 #define CPG_FRQCRC_ZFC_SHIFT 8
36 #define CPG_ADSPCKCR 0x0000025c
37 #define CPG_RCANCKCR 0x00000270
38
39 /* -----------------------------------------------------------------------------
40 * Z Clock
41 *
42 * Traits of this clock:
43 * prepare - clk_prepare only ensures that parents are prepared
44 * enable - clk_enable only ensures that parents are enabled
45 * rate - rate is adjustable. clk->rate = parent->rate * mult / 32
46 * parent - fixed parent. No clk_set_parent support
47 */
48
49 struct cpg_z_clk {
50 struct clk_hw hw;
51 void __iomem *reg;
52 void __iomem *kick_reg;
53 };
54
55 #define to_z_clk(_hw) container_of(_hw, struct cpg_z_clk, hw)
56
cpg_z_clk_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)57 static unsigned long cpg_z_clk_recalc_rate(struct clk_hw *hw,
58 unsigned long parent_rate)
59 {
60 struct cpg_z_clk *zclk = to_z_clk(hw);
61 unsigned int mult;
62 unsigned int val;
63
64 val = (clk_readl(zclk->reg) & CPG_FRQCRC_ZFC_MASK)
65 >> CPG_FRQCRC_ZFC_SHIFT;
66 mult = 32 - val;
67
68 return div_u64((u64)parent_rate * mult, 32);
69 }
70
cpg_z_clk_round_rate(struct clk_hw * hw,unsigned long rate,unsigned long * parent_rate)71 static long cpg_z_clk_round_rate(struct clk_hw *hw, unsigned long rate,
72 unsigned long *parent_rate)
73 {
74 unsigned long prate = *parent_rate;
75 unsigned int mult;
76
77 if (!prate)
78 prate = 1;
79
80 mult = div_u64((u64)rate * 32, prate);
81 mult = clamp(mult, 1U, 32U);
82
83 return *parent_rate / 32 * mult;
84 }
85
cpg_z_clk_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)86 static int cpg_z_clk_set_rate(struct clk_hw *hw, unsigned long rate,
87 unsigned long parent_rate)
88 {
89 struct cpg_z_clk *zclk = to_z_clk(hw);
90 unsigned int mult;
91 u32 val, kick;
92 unsigned int i;
93
94 mult = div_u64((u64)rate * 32, parent_rate);
95 mult = clamp(mult, 1U, 32U);
96
97 if (clk_readl(zclk->kick_reg) & CPG_FRQCRB_KICK)
98 return -EBUSY;
99
100 val = clk_readl(zclk->reg);
101 val &= ~CPG_FRQCRC_ZFC_MASK;
102 val |= (32 - mult) << CPG_FRQCRC_ZFC_SHIFT;
103 clk_writel(val, zclk->reg);
104
105 /*
106 * Set KICK bit in FRQCRB to update hardware setting and wait for
107 * clock change completion.
108 */
109 kick = clk_readl(zclk->kick_reg);
110 kick |= CPG_FRQCRB_KICK;
111 clk_writel(kick, zclk->kick_reg);
112
113 /*
114 * Note: There is no HW information about the worst case latency.
115 *
116 * Using experimental measurements, it seems that no more than
117 * ~10 iterations are needed, independently of the CPU rate.
118 * Since this value might be dependant of external xtal rate, pll1
119 * rate or even the other emulation clocks rate, use 1000 as a
120 * "super" safe value.
121 */
122 for (i = 1000; i; i--) {
123 if (!(clk_readl(zclk->kick_reg) & CPG_FRQCRB_KICK))
124 return 0;
125
126 cpu_relax();
127 }
128
129 return -ETIMEDOUT;
130 }
131
132 static const struct clk_ops cpg_z_clk_ops = {
133 .recalc_rate = cpg_z_clk_recalc_rate,
134 .round_rate = cpg_z_clk_round_rate,
135 .set_rate = cpg_z_clk_set_rate,
136 };
137
cpg_z_clk_register(struct rcar_gen2_cpg * cpg)138 static struct clk * __init cpg_z_clk_register(struct rcar_gen2_cpg *cpg)
139 {
140 static const char *parent_name = "pll0";
141 struct clk_init_data init;
142 struct cpg_z_clk *zclk;
143 struct clk *clk;
144
145 zclk = kzalloc(sizeof(*zclk), GFP_KERNEL);
146 if (!zclk)
147 return ERR_PTR(-ENOMEM);
148
149 init.name = "z";
150 init.ops = &cpg_z_clk_ops;
151 init.flags = 0;
152 init.parent_names = &parent_name;
153 init.num_parents = 1;
154
155 zclk->reg = cpg->reg + CPG_FRQCRC;
156 zclk->kick_reg = cpg->reg + CPG_FRQCRB;
157 zclk->hw.init = &init;
158
159 clk = clk_register(NULL, &zclk->hw);
160 if (IS_ERR(clk))
161 kfree(zclk);
162
163 return clk;
164 }
165
cpg_rcan_clk_register(struct rcar_gen2_cpg * cpg,struct device_node * np)166 static struct clk * __init cpg_rcan_clk_register(struct rcar_gen2_cpg *cpg,
167 struct device_node *np)
168 {
169 const char *parent_name = of_clk_get_parent_name(np, 1);
170 struct clk_fixed_factor *fixed;
171 struct clk_gate *gate;
172 struct clk *clk;
173
174 fixed = kzalloc(sizeof(*fixed), GFP_KERNEL);
175 if (!fixed)
176 return ERR_PTR(-ENOMEM);
177
178 fixed->mult = 1;
179 fixed->div = 6;
180
181 gate = kzalloc(sizeof(*gate), GFP_KERNEL);
182 if (!gate) {
183 kfree(fixed);
184 return ERR_PTR(-ENOMEM);
185 }
186
187 gate->reg = cpg->reg + CPG_RCANCKCR;
188 gate->bit_idx = 8;
189 gate->flags = CLK_GATE_SET_TO_DISABLE;
190 gate->lock = &cpg->lock;
191
192 clk = clk_register_composite(NULL, "rcan", &parent_name, 1, NULL, NULL,
193 &fixed->hw, &clk_fixed_factor_ops,
194 &gate->hw, &clk_gate_ops, 0);
195 if (IS_ERR(clk)) {
196 kfree(gate);
197 kfree(fixed);
198 }
199
200 return clk;
201 }
202
203 /* ADSP divisors */
204 static const struct clk_div_table cpg_adsp_div_table[] = {
205 { 1, 3 }, { 2, 4 }, { 3, 6 }, { 4, 8 },
206 { 5, 12 }, { 6, 16 }, { 7, 18 }, { 8, 24 },
207 { 10, 36 }, { 11, 48 }, { 0, 0 },
208 };
209
cpg_adsp_clk_register(struct rcar_gen2_cpg * cpg)210 static struct clk * __init cpg_adsp_clk_register(struct rcar_gen2_cpg *cpg)
211 {
212 const char *parent_name = "pll1";
213 struct clk_divider *div;
214 struct clk_gate *gate;
215 struct clk *clk;
216
217 div = kzalloc(sizeof(*div), GFP_KERNEL);
218 if (!div)
219 return ERR_PTR(-ENOMEM);
220
221 div->reg = cpg->reg + CPG_ADSPCKCR;
222 div->width = 4;
223 div->table = cpg_adsp_div_table;
224 div->lock = &cpg->lock;
225
226 gate = kzalloc(sizeof(*gate), GFP_KERNEL);
227 if (!gate) {
228 kfree(div);
229 return ERR_PTR(-ENOMEM);
230 }
231
232 gate->reg = cpg->reg + CPG_ADSPCKCR;
233 gate->bit_idx = 8;
234 gate->flags = CLK_GATE_SET_TO_DISABLE;
235 gate->lock = &cpg->lock;
236
237 clk = clk_register_composite(NULL, "adsp", &parent_name, 1, NULL, NULL,
238 &div->hw, &clk_divider_ops,
239 &gate->hw, &clk_gate_ops, 0);
240 if (IS_ERR(clk)) {
241 kfree(gate);
242 kfree(div);
243 }
244
245 return clk;
246 }
247
248 /* -----------------------------------------------------------------------------
249 * CPG Clock Data
250 */
251
252 /*
253 * MD EXTAL PLL0 PLL1 PLL3
254 * 14 13 19 (MHz) *1 *1
255 *---------------------------------------------------
256 * 0 0 0 15 x 1 x172/2 x208/2 x106
257 * 0 0 1 15 x 1 x172/2 x208/2 x88
258 * 0 1 0 20 x 1 x130/2 x156/2 x80
259 * 0 1 1 20 x 1 x130/2 x156/2 x66
260 * 1 0 0 26 / 2 x200/2 x240/2 x122
261 * 1 0 1 26 / 2 x200/2 x240/2 x102
262 * 1 1 0 30 / 2 x172/2 x208/2 x106
263 * 1 1 1 30 / 2 x172/2 x208/2 x88
264 *
265 * *1 : Table 7.6 indicates VCO ouput (PLLx = VCO/2)
266 */
267 #define CPG_PLL_CONFIG_INDEX(md) ((((md) & BIT(14)) >> 12) | \
268 (((md) & BIT(13)) >> 12) | \
269 (((md) & BIT(19)) >> 19))
270 struct cpg_pll_config {
271 unsigned int extal_div;
272 unsigned int pll1_mult;
273 unsigned int pll3_mult;
274 };
275
276 static const struct cpg_pll_config cpg_pll_configs[8] __initconst = {
277 { 1, 208, 106 }, { 1, 208, 88 }, { 1, 156, 80 }, { 1, 156, 66 },
278 { 2, 240, 122 }, { 2, 240, 102 }, { 2, 208, 106 }, { 2, 208, 88 },
279 };
280
281 /* SDHI divisors */
282 static const struct clk_div_table cpg_sdh_div_table[] = {
283 { 0, 2 }, { 1, 3 }, { 2, 4 }, { 3, 6 },
284 { 4, 8 }, { 5, 12 }, { 6, 16 }, { 7, 18 },
285 { 8, 24 }, { 10, 36 }, { 11, 48 }, { 0, 0 },
286 };
287
288 static const struct clk_div_table cpg_sd01_div_table[] = {
289 { 4, 8 },
290 { 5, 12 }, { 6, 16 }, { 7, 18 }, { 8, 24 },
291 { 10, 36 }, { 11, 48 }, { 12, 10 }, { 0, 0 },
292 };
293
294 /* -----------------------------------------------------------------------------
295 * Initialization
296 */
297
298 static u32 cpg_mode __initdata;
299
300 static struct clk * __init
rcar_gen2_cpg_register_clock(struct device_node * np,struct rcar_gen2_cpg * cpg,const struct cpg_pll_config * config,const char * name)301 rcar_gen2_cpg_register_clock(struct device_node *np, struct rcar_gen2_cpg *cpg,
302 const struct cpg_pll_config *config,
303 const char *name)
304 {
305 const struct clk_div_table *table = NULL;
306 const char *parent_name;
307 unsigned int shift;
308 unsigned int mult = 1;
309 unsigned int div = 1;
310
311 if (!strcmp(name, "main")) {
312 parent_name = of_clk_get_parent_name(np, 0);
313 div = config->extal_div;
314 } else if (!strcmp(name, "pll0")) {
315 /* PLL0 is a configurable multiplier clock. Register it as a
316 * fixed factor clock for now as there's no generic multiplier
317 * clock implementation and we currently have no need to change
318 * the multiplier value.
319 */
320 u32 value = clk_readl(cpg->reg + CPG_PLL0CR);
321 parent_name = "main";
322 mult = ((value >> 24) & ((1 << 7) - 1)) + 1;
323 } else if (!strcmp(name, "pll1")) {
324 parent_name = "main";
325 mult = config->pll1_mult / 2;
326 } else if (!strcmp(name, "pll3")) {
327 parent_name = "main";
328 mult = config->pll3_mult;
329 } else if (!strcmp(name, "lb")) {
330 parent_name = "pll1";
331 div = cpg_mode & BIT(18) ? 36 : 24;
332 } else if (!strcmp(name, "qspi")) {
333 parent_name = "pll1_div2";
334 div = (cpg_mode & (BIT(3) | BIT(2) | BIT(1))) == BIT(2)
335 ? 8 : 10;
336 } else if (!strcmp(name, "sdh")) {
337 parent_name = "pll1";
338 table = cpg_sdh_div_table;
339 shift = 8;
340 } else if (!strcmp(name, "sd0")) {
341 parent_name = "pll1";
342 table = cpg_sd01_div_table;
343 shift = 4;
344 } else if (!strcmp(name, "sd1")) {
345 parent_name = "pll1";
346 table = cpg_sd01_div_table;
347 shift = 0;
348 } else if (!strcmp(name, "z")) {
349 return cpg_z_clk_register(cpg);
350 } else if (!strcmp(name, "rcan")) {
351 return cpg_rcan_clk_register(cpg, np);
352 } else if (!strcmp(name, "adsp")) {
353 return cpg_adsp_clk_register(cpg);
354 } else {
355 return ERR_PTR(-EINVAL);
356 }
357
358 if (!table)
359 return clk_register_fixed_factor(NULL, name, parent_name, 0,
360 mult, div);
361 else
362 return clk_register_divider_table(NULL, name, parent_name, 0,
363 cpg->reg + CPG_SDCKCR, shift,
364 4, 0, table, &cpg->lock);
365 }
366
rcar_gen2_cpg_clocks_init(struct device_node * np)367 static void __init rcar_gen2_cpg_clocks_init(struct device_node *np)
368 {
369 const struct cpg_pll_config *config;
370 struct rcar_gen2_cpg *cpg;
371 struct clk **clks;
372 unsigned int i;
373 int num_clks;
374
375 num_clks = of_property_count_strings(np, "clock-output-names");
376 if (num_clks < 0) {
377 pr_err("%s: failed to count clocks\n", __func__);
378 return;
379 }
380
381 cpg = kzalloc(sizeof(*cpg), GFP_KERNEL);
382 clks = kzalloc(num_clks * sizeof(*clks), GFP_KERNEL);
383 if (cpg == NULL || clks == NULL) {
384 /* We're leaking memory on purpose, there's no point in cleaning
385 * up as the system won't boot anyway.
386 */
387 pr_err("%s: failed to allocate cpg\n", __func__);
388 return;
389 }
390
391 spin_lock_init(&cpg->lock);
392
393 cpg->data.clks = clks;
394 cpg->data.clk_num = num_clks;
395
396 cpg->reg = of_iomap(np, 0);
397 if (WARN_ON(cpg->reg == NULL))
398 return;
399
400 config = &cpg_pll_configs[CPG_PLL_CONFIG_INDEX(cpg_mode)];
401
402 for (i = 0; i < num_clks; ++i) {
403 const char *name;
404 struct clk *clk;
405
406 of_property_read_string_index(np, "clock-output-names", i,
407 &name);
408
409 clk = rcar_gen2_cpg_register_clock(np, cpg, config, name);
410 if (IS_ERR(clk))
411 pr_err("%s: failed to register %s %s clock (%ld)\n",
412 __func__, np->name, name, PTR_ERR(clk));
413 else
414 cpg->data.clks[i] = clk;
415 }
416
417 of_clk_add_provider(np, of_clk_src_onecell_get, &cpg->data);
418
419 cpg_mstp_add_clk_domain(np);
420 }
421 CLK_OF_DECLARE(rcar_gen2_cpg_clks, "renesas,rcar-gen2-cpg-clocks",
422 rcar_gen2_cpg_clocks_init);
423
rcar_gen2_clocks_init(u32 mode)424 void __init rcar_gen2_clocks_init(u32 mode)
425 {
426 cpg_mode = mode;
427
428 of_clk_init(NULL);
429 }
430