1// SPDX-License-Identifier: GPL-2.0
2/*
3 * R-Car Gen2 Clock Pulse Generator
4 *
5 * Copyright (C) 2016 Cogent Embedded Inc.
6 */
7
8#include <linux/bug.h>
9#include <linux/clk.h>
10#include <linux/clk-provider.h>
11#include <linux/device.h>
12#include <linux/err.h>
13#include <linux/init.h>
14#include <linux/io.h>
15#include <linux/slab.h>
16#include <linux/sys_soc.h>
17
18#include "renesas-cpg-mssr.h"
19#include "rcar-gen2-cpg.h"
20
21#define CPG_FRQCRB 0x0004
22#define CPG_FRQCRB_KICK BIT(31)
23#define CPG_SDCKCR 0x0074
24#define CPG_PLL0CR 0x00d8
25#define CPG_PLL0CR_STC_SHIFT 24
26#define CPG_PLL0CR_STC_MASK (0x7f << CPG_PLL0CR_STC_SHIFT)
27#define CPG_FRQCRC 0x00e0
28#define CPG_FRQCRC_ZFC_SHIFT 8
29#define CPG_FRQCRC_ZFC_MASK (0x1f << CPG_FRQCRC_ZFC_SHIFT)
30#define CPG_ADSPCKCR 0x025c
31#define CPG_RCANCKCR 0x0270
32
33static spinlock_t cpg_lock;
34
35/*
36 * Z Clock
37 *
38 * Traits of this clock:
39 * prepare - clk_prepare only ensures that parents are prepared
40 * enable - clk_enable only ensures that parents are enabled
41 * rate - rate is adjustable. clk->rate = parent->rate * mult / 32
42 * parent - fixed parent. No clk_set_parent support
43 */
44
45struct cpg_z_clk {
46 struct clk_hw hw;
47 void __iomem *reg;
48 void __iomem *kick_reg;
49};
50
51#define to_z_clk(_hw) container_of(_hw, struct cpg_z_clk, hw)
52
53static unsigned long cpg_z_clk_recalc_rate(struct clk_hw *hw,
54 unsigned long parent_rate)
55{
56 struct cpg_z_clk *zclk = to_z_clk(hw);
57 unsigned int mult;
58 unsigned int val;
59
60 val = (readl(addr: zclk->reg) & CPG_FRQCRC_ZFC_MASK) >> CPG_FRQCRC_ZFC_SHIFT;
61 mult = 32 - val;
62
63 return div_u64(dividend: (u64)parent_rate * mult, divisor: 32);
64}
65
66static int cpg_z_clk_determine_rate(struct clk_hw *hw,
67 struct clk_rate_request *req)
68{
69 unsigned long prate = req->best_parent_rate;
70 unsigned int min_mult, max_mult, mult;
71
72 min_mult = max(div64_ul(req->min_rate * 32ULL, prate), 1ULL);
73 max_mult = min(div64_ul(req->max_rate * 32ULL, prate), 32ULL);
74 if (max_mult < min_mult)
75 return -EINVAL;
76
77 mult = div64_ul(req->rate * 32ULL, prate);
78 mult = clamp(mult, min_mult, max_mult);
79
80 req->rate = div_u64(dividend: (u64)prate * mult, divisor: 32);
81 return 0;
82}
83
84static int cpg_z_clk_set_rate(struct clk_hw *hw, unsigned long rate,
85 unsigned long parent_rate)
86{
87 struct cpg_z_clk *zclk = to_z_clk(hw);
88 unsigned int mult;
89 u32 val, kick;
90 unsigned int i;
91
92 mult = div64_ul(rate * 32ULL, parent_rate);
93 mult = clamp(mult, 1U, 32U);
94
95 if (readl(addr: zclk->kick_reg) & CPG_FRQCRB_KICK)
96 return -EBUSY;
97
98 val = readl(addr: zclk->reg);
99 val &= ~CPG_FRQCRC_ZFC_MASK;
100 val |= (32 - mult) << CPG_FRQCRC_ZFC_SHIFT;
101 writel(val, addr: zclk->reg);
102
103 /*
104 * Set KICK bit in FRQCRB to update hardware setting and wait for
105 * clock change completion.
106 */
107 kick = readl(addr: zclk->kick_reg);
108 kick |= CPG_FRQCRB_KICK;
109 writel(val: kick, addr: zclk->kick_reg);
110
111 /*
112 * Note: There is no HW information about the worst case latency.
113 *
114 * Using experimental measurements, it seems that no more than
115 * ~10 iterations are needed, independently of the CPU rate.
116 * Since this value might be dependent on external xtal rate, pll1
117 * rate or even the other emulation clocks rate, use 1000 as a
118 * "super" safe value.
119 */
120 for (i = 1000; i; i--) {
121 if (!(readl(addr: zclk->kick_reg) & CPG_FRQCRB_KICK))
122 return 0;
123
124 cpu_relax();
125 }
126
127 return -ETIMEDOUT;
128}
129
130static const struct clk_ops cpg_z_clk_ops = {
131 .recalc_rate = cpg_z_clk_recalc_rate,
132 .determine_rate = cpg_z_clk_determine_rate,
133 .set_rate = cpg_z_clk_set_rate,
134};
135
136static struct clk * __init cpg_z_clk_register(const char *name,
137 const char *parent_name,
138 void __iomem *base)
139{
140 struct clk_init_data init = {};
141 struct cpg_z_clk *zclk;
142 struct clk *clk;
143
144 zclk = kzalloc(size: sizeof(*zclk), GFP_KERNEL);
145 if (!zclk)
146 return ERR_PTR(error: -ENOMEM);
147
148 init.name = name;
149 init.ops = &cpg_z_clk_ops;
150 init.parent_names = &parent_name;
151 init.num_parents = 1;
152
153 zclk->reg = base + CPG_FRQCRC;
154 zclk->kick_reg = base + CPG_FRQCRB;
155 zclk->hw.init = &init;
156
157 clk = clk_register(NULL, hw: &zclk->hw);
158 if (IS_ERR(ptr: clk))
159 kfree(objp: zclk);
160
161 return clk;
162}
163
164static struct clk * __init cpg_rcan_clk_register(const char *name,
165 const char *parent_name,
166 void __iomem *base)
167{
168 struct clk_fixed_factor *fixed;
169 struct clk_gate *gate;
170 struct clk *clk;
171
172 fixed = kzalloc(size: sizeof(*fixed), GFP_KERNEL);
173 if (!fixed)
174 return ERR_PTR(error: -ENOMEM);
175
176 fixed->mult = 1;
177 fixed->div = 6;
178
179 gate = kzalloc(size: sizeof(*gate), GFP_KERNEL);
180 if (!gate) {
181 kfree(objp: fixed);
182 return ERR_PTR(error: -ENOMEM);
183 }
184
185 gate->reg = base + CPG_RCANCKCR;
186 gate->bit_idx = 8;
187 gate->flags = CLK_GATE_SET_TO_DISABLE;
188 gate->lock = &cpg_lock;
189
190 clk = clk_register_composite(NULL, name, parent_names: &parent_name, num_parents: 1, NULL, NULL,
191 rate_hw: &fixed->hw, rate_ops: &clk_fixed_factor_ops,
192 gate_hw: &gate->hw, gate_ops: &clk_gate_ops, flags: 0);
193 if (IS_ERR(ptr: clk)) {
194 kfree(objp: gate);
195 kfree(objp: fixed);
196 }
197
198 return clk;
199}
200
201/* ADSP divisors */
202static const struct clk_div_table cpg_adsp_div_table[] = {
203 { 1, 3 }, { 2, 4 }, { 3, 6 }, { 4, 8 },
204 { 5, 12 }, { 6, 16 }, { 7, 18 }, { 8, 24 },
205 { 10, 36 }, { 11, 48 }, { 0, 0 },
206};
207
208static struct clk * __init cpg_adsp_clk_register(const char *name,
209 const char *parent_name,
210 void __iomem *base)
211{
212 struct clk_divider *div;
213 struct clk_gate *gate;
214 struct clk *clk;
215
216 div = kzalloc(size: sizeof(*div), GFP_KERNEL);
217 if (!div)
218 return ERR_PTR(error: -ENOMEM);
219
220 div->reg = base + CPG_ADSPCKCR;
221 div->width = 4;
222 div->table = cpg_adsp_div_table;
223 div->lock = &cpg_lock;
224
225 gate = kzalloc(size: sizeof(*gate), GFP_KERNEL);
226 if (!gate) {
227 kfree(objp: div);
228 return ERR_PTR(error: -ENOMEM);
229 }
230
231 gate->reg = base + CPG_ADSPCKCR;
232 gate->bit_idx = 8;
233 gate->flags = CLK_GATE_SET_TO_DISABLE;
234 gate->lock = &cpg_lock;
235
236 clk = clk_register_composite(NULL, name, parent_names: &parent_name, num_parents: 1, NULL, NULL,
237 rate_hw: &div->hw, rate_ops: &clk_divider_ops,
238 gate_hw: &gate->hw, gate_ops: &clk_gate_ops, flags: 0);
239 if (IS_ERR(ptr: clk)) {
240 kfree(objp: gate);
241 kfree(objp: div);
242 }
243
244 return clk;
245}
246
247/* SDHI divisors */
248static const struct clk_div_table cpg_sdh_div_table[] = {
249 { 0, 2 }, { 1, 3 }, { 2, 4 }, { 3, 6 },
250 { 4, 8 }, { 5, 12 }, { 6, 16 }, { 7, 18 },
251 { 8, 24 }, { 10, 36 }, { 11, 48 }, { 0, 0 },
252};
253
254static const struct clk_div_table cpg_sd01_div_table[] = {
255 { 4, 8 }, { 5, 12 }, { 6, 16 }, { 7, 18 },
256 { 8, 24 }, { 10, 36 }, { 11, 48 }, { 12, 10 },
257 { 0, 0 },
258};
259
260static const struct rcar_gen2_cpg_pll_config *cpg_pll_config __initdata;
261static unsigned int cpg_pll0_div __initdata;
262static u32 cpg_mode __initdata;
263static u32 cpg_quirks __initdata;
264
265#define SD_SKIP_FIRST BIT(0) /* Skip first clock in SD table */
266
267static const struct soc_device_attribute cpg_quirks_match[] __initconst = {
268 {
269 .soc_id = "r8a77470",
270 .data = (void *)SD_SKIP_FIRST,
271 },
272 { /* sentinel */ }
273};
274
275struct clk * __init rcar_gen2_cpg_clk_register(struct device *dev,
276 const struct cpg_core_clk *core, const struct cpg_mssr_info *info,
277 struct clk **clks, void __iomem *base,
278 struct raw_notifier_head *notifiers)
279{
280 const struct clk_div_table *table = NULL;
281 const struct clk *parent;
282 const char *parent_name;
283 unsigned int mult = 1;
284 unsigned int div = 1;
285 unsigned int shift;
286
287 parent = clks[core->parent];
288 if (IS_ERR(ptr: parent))
289 return ERR_CAST(ptr: parent);
290
291 parent_name = __clk_get_name(clk: parent);
292
293 switch (core->type) {
294 /* R-Car Gen2 */
295 case CLK_TYPE_GEN2_MAIN:
296 div = cpg_pll_config->extal_div;
297 break;
298
299 case CLK_TYPE_GEN2_PLL0:
300 /*
301 * PLL0 is a configurable multiplier clock except on R-Car
302 * V2H/E2. Register the PLL0 clock as a fixed factor clock for
303 * now as there's no generic multiplier clock implementation and
304 * we currently have no need to change the multiplier value.
305 */
306 mult = cpg_pll_config->pll0_mult;
307 div = cpg_pll0_div;
308 if (!mult) {
309 u32 pll0cr = readl(addr: base + CPG_PLL0CR);
310
311 mult = (((pll0cr & CPG_PLL0CR_STC_MASK) >>
312 CPG_PLL0CR_STC_SHIFT) + 1) * 2;
313 }
314 break;
315
316 case CLK_TYPE_GEN2_PLL1:
317 mult = cpg_pll_config->pll1_mult / 2;
318 break;
319
320 case CLK_TYPE_GEN2_PLL3:
321 mult = cpg_pll_config->pll3_mult;
322 break;
323
324 case CLK_TYPE_GEN2_Z:
325 return cpg_z_clk_register(name: core->name, parent_name, base);
326
327 case CLK_TYPE_GEN2_LB:
328 div = cpg_mode & BIT(18) ? 36 : 24;
329 break;
330
331 case CLK_TYPE_GEN2_ADSP:
332 return cpg_adsp_clk_register(name: core->name, parent_name, base);
333
334 case CLK_TYPE_GEN2_SDH:
335 table = cpg_sdh_div_table;
336 shift = 8;
337 break;
338
339 case CLK_TYPE_GEN2_SD0:
340 table = cpg_sd01_div_table;
341 if (cpg_quirks & SD_SKIP_FIRST)
342 table++;
343
344 shift = 4;
345 break;
346
347 case CLK_TYPE_GEN2_SD1:
348 table = cpg_sd01_div_table;
349 if (cpg_quirks & SD_SKIP_FIRST)
350 table++;
351
352 shift = 0;
353 break;
354
355 case CLK_TYPE_GEN2_QSPI:
356 div = (cpg_mode & (BIT(3) | BIT(2) | BIT(1))) == BIT(2) ?
357 8 : 10;
358 break;
359
360 case CLK_TYPE_GEN2_RCAN:
361 return cpg_rcan_clk_register(name: core->name, parent_name, base);
362
363 default:
364 return ERR_PTR(error: -EINVAL);
365 }
366
367 if (!table)
368 return clk_register_fixed_factor(NULL, name: core->name, parent_name,
369 flags: 0, mult, div);
370 else
371 return clk_register_divider_table(NULL, name: core->name,
372 parent_name, flags: 0,
373 reg: base + CPG_SDCKCR, shift, width: 4,
374 clk_divider_flags: 0, table, lock: &cpg_lock);
375}
376
377int __init rcar_gen2_cpg_init(const struct rcar_gen2_cpg_pll_config *config,
378 unsigned int pll0_div, u32 mode)
379{
380 const struct soc_device_attribute *attr;
381
382 cpg_pll_config = config;
383 cpg_pll0_div = pll0_div;
384 cpg_mode = mode;
385 attr = soc_device_match(matches: cpg_quirks_match);
386 if (attr)
387 cpg_quirks = (uintptr_t)attr->data;
388 pr_debug("%s: mode = 0x%x quirks = 0x%x\n", __func__, mode, cpg_quirks);
389
390 spin_lock_init(&cpg_lock);
391
392 return 0;
393}
394

source code of linux/drivers/clk/renesas/rcar-gen2-cpg.c