1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
4 * Copyright (C) 2007 Eugene Konev <ejka@openwrt.org>
5 * Copyright (C) 2009 Florian Fainelli <florian@openwrt.org>
6 */
7
8 #include <linux/kernel.h>
9 #include <linux/init.h>
10 #include <linux/types.h>
11 #include <linux/export.h>
12 #include <linux/delay.h>
13 #include <linux/gcd.h>
14 #include <linux/io.h>
15 #include <linux/err.h>
16 #include <linux/clk.h>
17
18 #include <asm/addrspace.h>
19 #include <asm/mach-ar7/ar7.h>
20
21 #define BOOT_PLL_SOURCE_MASK 0x3
22 #define CPU_PLL_SOURCE_SHIFT 16
23 #define BUS_PLL_SOURCE_SHIFT 14
24 #define USB_PLL_SOURCE_SHIFT 18
25 #define DSP_PLL_SOURCE_SHIFT 22
26 #define BOOT_PLL_SOURCE_AFE 0
27 #define BOOT_PLL_SOURCE_BUS 0
28 #define BOOT_PLL_SOURCE_REF 1
29 #define BOOT_PLL_SOURCE_XTAL 2
30 #define BOOT_PLL_SOURCE_CPU 3
31 #define BOOT_PLL_BYPASS 0x00000020
32 #define BOOT_PLL_ASYNC_MODE 0x02000000
33 #define BOOT_PLL_2TO1_MODE 0x00008000
34
35 #define TNETD7200_CLOCK_ID_CPU 0
36 #define TNETD7200_CLOCK_ID_DSP 1
37 #define TNETD7200_CLOCK_ID_USB 2
38
39 #define TNETD7200_DEF_CPU_CLK 211000000
40 #define TNETD7200_DEF_DSP_CLK 125000000
41 #define TNETD7200_DEF_USB_CLK 48000000
42
43 struct tnetd7300_clock {
44 u32 ctrl;
45 #define PREDIV_MASK 0x001f0000
46 #define PREDIV_SHIFT 16
47 #define POSTDIV_MASK 0x0000001f
48 u32 unused1[3];
49 u32 pll;
50 #define MUL_MASK 0x0000f000
51 #define MUL_SHIFT 12
52 #define PLL_MODE_MASK 0x00000001
53 #define PLL_NDIV 0x00000800
54 #define PLL_DIV 0x00000002
55 #define PLL_STATUS 0x00000001
56 u32 unused2[3];
57 };
58
59 struct tnetd7300_clocks {
60 struct tnetd7300_clock bus;
61 struct tnetd7300_clock cpu;
62 struct tnetd7300_clock usb;
63 struct tnetd7300_clock dsp;
64 };
65
66 struct tnetd7200_clock {
67 u32 ctrl;
68 u32 unused1[3];
69 #define DIVISOR_ENABLE_MASK 0x00008000
70 u32 mul;
71 u32 prediv;
72 u32 postdiv;
73 u32 postdiv2;
74 u32 unused2[6];
75 u32 cmd;
76 u32 status;
77 u32 cmden;
78 u32 padding[15];
79 };
80
81 struct tnetd7200_clocks {
82 struct tnetd7200_clock cpu;
83 struct tnetd7200_clock dsp;
84 struct tnetd7200_clock usb;
85 };
86
87 static struct clk bus_clk = {
88 .rate = 125000000,
89 };
90
91 static struct clk cpu_clk = {
92 .rate = 150000000,
93 };
94
95 static struct clk dsp_clk;
96 static struct clk vbus_clk;
97
approximate(int base,int target,int * prediv,int * postdiv,int * mul)98 static void approximate(int base, int target, int *prediv,
99 int *postdiv, int *mul)
100 {
101 int i, j, k, freq, res = target;
102 for (i = 1; i <= 16; i++)
103 for (j = 1; j <= 32; j++)
104 for (k = 1; k <= 32; k++) {
105 freq = abs(base / j * i / k - target);
106 if (freq < res) {
107 res = freq;
108 *mul = i;
109 *prediv = j;
110 *postdiv = k;
111 }
112 }
113 }
114
calculate(int base,int target,int * prediv,int * postdiv,int * mul)115 static void calculate(int base, int target, int *prediv, int *postdiv,
116 int *mul)
117 {
118 int tmp_gcd, tmp_base, tmp_freq;
119
120 for (*prediv = 1; *prediv <= 32; (*prediv)++) {
121 tmp_base = base / *prediv;
122 tmp_gcd = gcd(target, tmp_base);
123 *mul = target / tmp_gcd;
124 *postdiv = tmp_base / tmp_gcd;
125 if ((*mul < 1) || (*mul >= 16))
126 continue;
127 if ((*postdiv > 0) & (*postdiv <= 32))
128 break;
129 }
130
131 if (base / *prediv * *mul / *postdiv != target) {
132 approximate(base, target, prediv, postdiv, mul);
133 tmp_freq = base / *prediv * *mul / *postdiv;
134 printk(KERN_WARNING
135 "Adjusted requested frequency %d to %d\n",
136 target, tmp_freq);
137 }
138
139 printk(KERN_DEBUG "Clocks: prediv: %d, postdiv: %d, mul: %d\n",
140 *prediv, *postdiv, *mul);
141 }
142
tnetd7300_dsp_clock(void)143 static int tnetd7300_dsp_clock(void)
144 {
145 u32 didr1, didr2;
146 u8 rev = ar7_chip_rev();
147 didr1 = readl((void *)KSEG1ADDR(AR7_REGS_GPIO + 0x18));
148 didr2 = readl((void *)KSEG1ADDR(AR7_REGS_GPIO + 0x1c));
149 if (didr2 & (1 << 23))
150 return 0;
151 if ((rev >= 0x23) && (rev != 0x57))
152 return 250000000;
153 if ((((didr2 & 0x1fff) << 10) | ((didr1 & 0xffc00000) >> 22))
154 > 4208000)
155 return 250000000;
156 return 0;
157 }
158
tnetd7300_get_clock(u32 shift,struct tnetd7300_clock * clock,u32 * bootcr,u32 bus_clock)159 static int tnetd7300_get_clock(u32 shift, struct tnetd7300_clock *clock,
160 u32 *bootcr, u32 bus_clock)
161 {
162 int product;
163 int base_clock = AR7_REF_CLOCK;
164 u32 ctrl = readl(&clock->ctrl);
165 u32 pll = readl(&clock->pll);
166 int prediv = ((ctrl & PREDIV_MASK) >> PREDIV_SHIFT) + 1;
167 int postdiv = (ctrl & POSTDIV_MASK) + 1;
168 int divisor = prediv * postdiv;
169 int mul = ((pll & MUL_MASK) >> MUL_SHIFT) + 1;
170
171 switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
172 case BOOT_PLL_SOURCE_BUS:
173 base_clock = bus_clock;
174 break;
175 case BOOT_PLL_SOURCE_REF:
176 base_clock = AR7_REF_CLOCK;
177 break;
178 case BOOT_PLL_SOURCE_XTAL:
179 base_clock = AR7_XTAL_CLOCK;
180 break;
181 case BOOT_PLL_SOURCE_CPU:
182 base_clock = cpu_clk.rate;
183 break;
184 }
185
186 if (*bootcr & BOOT_PLL_BYPASS)
187 return base_clock / divisor;
188
189 if ((pll & PLL_MODE_MASK) == 0)
190 return (base_clock >> (mul / 16 + 1)) / divisor;
191
192 if ((pll & (PLL_NDIV | PLL_DIV)) == (PLL_NDIV | PLL_DIV)) {
193 product = (mul & 1) ?
194 (base_clock * mul) >> 1 :
195 (base_clock * (mul - 1)) >> 2;
196 return product / divisor;
197 }
198
199 if (mul == 16)
200 return base_clock / divisor;
201
202 return base_clock * mul / divisor;
203 }
204
tnetd7300_set_clock(u32 shift,struct tnetd7300_clock * clock,u32 * bootcr,u32 frequency)205 static void tnetd7300_set_clock(u32 shift, struct tnetd7300_clock *clock,
206 u32 *bootcr, u32 frequency)
207 {
208 int prediv, postdiv, mul;
209 int base_clock = bus_clk.rate;
210
211 switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
212 case BOOT_PLL_SOURCE_BUS:
213 base_clock = bus_clk.rate;
214 break;
215 case BOOT_PLL_SOURCE_REF:
216 base_clock = AR7_REF_CLOCK;
217 break;
218 case BOOT_PLL_SOURCE_XTAL:
219 base_clock = AR7_XTAL_CLOCK;
220 break;
221 case BOOT_PLL_SOURCE_CPU:
222 base_clock = cpu_clk.rate;
223 break;
224 }
225
226 calculate(base_clock, frequency, &prediv, &postdiv, &mul);
227
228 writel(((prediv - 1) << PREDIV_SHIFT) | (postdiv - 1), &clock->ctrl);
229 mdelay(1);
230 writel(4, &clock->pll);
231 while (readl(&clock->pll) & PLL_STATUS)
232 ;
233 writel(((mul - 1) << MUL_SHIFT) | (0xff << 3) | 0x0e, &clock->pll);
234 mdelay(75);
235 }
236
tnetd7300_init_clocks(void)237 static void __init tnetd7300_init_clocks(void)
238 {
239 u32 *bootcr = (u32 *)ioremap(AR7_REGS_DCL, 4);
240 struct tnetd7300_clocks *clocks =
241 ioremap(UR8_REGS_CLOCKS,
242 sizeof(struct tnetd7300_clocks));
243
244 bus_clk.rate = tnetd7300_get_clock(BUS_PLL_SOURCE_SHIFT,
245 &clocks->bus, bootcr, AR7_AFE_CLOCK);
246
247 if (*bootcr & BOOT_PLL_ASYNC_MODE)
248 cpu_clk.rate = tnetd7300_get_clock(CPU_PLL_SOURCE_SHIFT,
249 &clocks->cpu, bootcr, AR7_AFE_CLOCK);
250 else
251 cpu_clk.rate = bus_clk.rate;
252
253 if (dsp_clk.rate == 250000000)
254 tnetd7300_set_clock(DSP_PLL_SOURCE_SHIFT, &clocks->dsp,
255 bootcr, dsp_clk.rate);
256
257 iounmap(clocks);
258 iounmap(bootcr);
259 }
260
tnetd7200_set_clock(int base,struct tnetd7200_clock * clock,int prediv,int postdiv,int postdiv2,int mul,u32 frequency)261 static void tnetd7200_set_clock(int base, struct tnetd7200_clock *clock,
262 int prediv, int postdiv, int postdiv2, int mul, u32 frequency)
263 {
264 printk(KERN_INFO
265 "Clocks: base = %d, frequency = %u, prediv = %d, "
266 "postdiv = %d, postdiv2 = %d, mul = %d\n",
267 base, frequency, prediv, postdiv, postdiv2, mul);
268
269 writel(0, &clock->ctrl);
270 writel(DIVISOR_ENABLE_MASK | ((prediv - 1) & 0x1F), &clock->prediv);
271 writel((mul - 1) & 0xF, &clock->mul);
272
273 while (readl(&clock->status) & 0x1)
274 ; /* nop */
275
276 writel(DIVISOR_ENABLE_MASK | ((postdiv - 1) & 0x1F), &clock->postdiv);
277
278 writel(readl(&clock->cmden) | 1, &clock->cmden);
279 writel(readl(&clock->cmd) | 1, &clock->cmd);
280
281 while (readl(&clock->status) & 0x1)
282 ; /* nop */
283
284 writel(DIVISOR_ENABLE_MASK | ((postdiv2 - 1) & 0x1F), &clock->postdiv2);
285
286 writel(readl(&clock->cmden) | 1, &clock->cmden);
287 writel(readl(&clock->cmd) | 1, &clock->cmd);
288
289 while (readl(&clock->status) & 0x1)
290 ; /* nop */
291
292 writel(readl(&clock->ctrl) | 1, &clock->ctrl);
293 }
294
tnetd7200_get_clock_base(int clock_id,u32 * bootcr)295 static int tnetd7200_get_clock_base(int clock_id, u32 *bootcr)
296 {
297 if (*bootcr & BOOT_PLL_ASYNC_MODE)
298 /* Async */
299 switch (clock_id) {
300 case TNETD7200_CLOCK_ID_DSP:
301 return AR7_REF_CLOCK;
302 default:
303 return AR7_AFE_CLOCK;
304 }
305 else
306 /* Sync */
307 if (*bootcr & BOOT_PLL_2TO1_MODE)
308 /* 2:1 */
309 switch (clock_id) {
310 case TNETD7200_CLOCK_ID_DSP:
311 return AR7_REF_CLOCK;
312 default:
313 return AR7_AFE_CLOCK;
314 }
315 else
316 /* 1:1 */
317 return AR7_REF_CLOCK;
318 }
319
320
tnetd7200_init_clocks(void)321 static void __init tnetd7200_init_clocks(void)
322 {
323 u32 *bootcr = (u32 *)ioremap(AR7_REGS_DCL, 4);
324 struct tnetd7200_clocks *clocks =
325 ioremap(AR7_REGS_CLOCKS,
326 sizeof(struct tnetd7200_clocks));
327 int cpu_base, cpu_mul, cpu_prediv, cpu_postdiv;
328 int dsp_base, dsp_mul, dsp_prediv, dsp_postdiv;
329 int usb_base, usb_mul, usb_prediv, usb_postdiv;
330
331 cpu_base = tnetd7200_get_clock_base(TNETD7200_CLOCK_ID_CPU, bootcr);
332 dsp_base = tnetd7200_get_clock_base(TNETD7200_CLOCK_ID_DSP, bootcr);
333
334 if (*bootcr & BOOT_PLL_ASYNC_MODE) {
335 printk(KERN_INFO "Clocks: Async mode\n");
336
337 printk(KERN_INFO "Clocks: Setting DSP clock\n");
338 calculate(dsp_base, TNETD7200_DEF_DSP_CLK,
339 &dsp_prediv, &dsp_postdiv, &dsp_mul);
340 bus_clk.rate =
341 ((dsp_base / dsp_prediv) * dsp_mul) / dsp_postdiv;
342 tnetd7200_set_clock(dsp_base, &clocks->dsp,
343 dsp_prediv, dsp_postdiv * 2, dsp_postdiv, dsp_mul * 2,
344 bus_clk.rate);
345
346 printk(KERN_INFO "Clocks: Setting CPU clock\n");
347 calculate(cpu_base, TNETD7200_DEF_CPU_CLK, &cpu_prediv,
348 &cpu_postdiv, &cpu_mul);
349 cpu_clk.rate =
350 ((cpu_base / cpu_prediv) * cpu_mul) / cpu_postdiv;
351 tnetd7200_set_clock(cpu_base, &clocks->cpu,
352 cpu_prediv, cpu_postdiv, -1, cpu_mul,
353 cpu_clk.rate);
354
355 } else
356 if (*bootcr & BOOT_PLL_2TO1_MODE) {
357 printk(KERN_INFO "Clocks: Sync 2:1 mode\n");
358
359 printk(KERN_INFO "Clocks: Setting CPU clock\n");
360 calculate(cpu_base, TNETD7200_DEF_CPU_CLK, &cpu_prediv,
361 &cpu_postdiv, &cpu_mul);
362 cpu_clk.rate = ((cpu_base / cpu_prediv) * cpu_mul)
363 / cpu_postdiv;
364 tnetd7200_set_clock(cpu_base, &clocks->cpu,
365 cpu_prediv, cpu_postdiv, -1, cpu_mul,
366 cpu_clk.rate);
367
368 printk(KERN_INFO "Clocks: Setting DSP clock\n");
369 calculate(dsp_base, TNETD7200_DEF_DSP_CLK, &dsp_prediv,
370 &dsp_postdiv, &dsp_mul);
371 bus_clk.rate = cpu_clk.rate / 2;
372 tnetd7200_set_clock(dsp_base, &clocks->dsp,
373 dsp_prediv, dsp_postdiv * 2, dsp_postdiv,
374 dsp_mul * 2, bus_clk.rate);
375 } else {
376 printk(KERN_INFO "Clocks: Sync 1:1 mode\n");
377
378 printk(KERN_INFO "Clocks: Setting DSP clock\n");
379 calculate(dsp_base, TNETD7200_DEF_DSP_CLK, &dsp_prediv,
380 &dsp_postdiv, &dsp_mul);
381 bus_clk.rate = ((dsp_base / dsp_prediv) * dsp_mul)
382 / dsp_postdiv;
383 tnetd7200_set_clock(dsp_base, &clocks->dsp,
384 dsp_prediv, dsp_postdiv * 2, dsp_postdiv,
385 dsp_mul * 2, bus_clk.rate);
386
387 cpu_clk.rate = bus_clk.rate;
388 }
389
390 printk(KERN_INFO "Clocks: Setting USB clock\n");
391 usb_base = bus_clk.rate;
392 calculate(usb_base, TNETD7200_DEF_USB_CLK, &usb_prediv,
393 &usb_postdiv, &usb_mul);
394 tnetd7200_set_clock(usb_base, &clocks->usb,
395 usb_prediv, usb_postdiv, -1, usb_mul,
396 TNETD7200_DEF_USB_CLK);
397
398 dsp_clk.rate = cpu_clk.rate;
399
400 iounmap(clocks);
401 iounmap(bootcr);
402 }
403
404 /*
405 * Linux clock API
406 */
clk_enable(struct clk * clk)407 int clk_enable(struct clk *clk)
408 {
409 return 0;
410 }
411 EXPORT_SYMBOL(clk_enable);
412
clk_disable(struct clk * clk)413 void clk_disable(struct clk *clk)
414 {
415 }
416 EXPORT_SYMBOL(clk_disable);
417
clk_get_rate(struct clk * clk)418 unsigned long clk_get_rate(struct clk *clk)
419 {
420 if (!clk)
421 return 0;
422
423 return clk->rate;
424 }
425 EXPORT_SYMBOL(clk_get_rate);
426
clk_get(struct device * dev,const char * id)427 struct clk *clk_get(struct device *dev, const char *id)
428 {
429 if (!strcmp(id, "bus"))
430 return &bus_clk;
431 /* cpmac and vbus share the same rate */
432 if (!strcmp(id, "cpmac"))
433 return &vbus_clk;
434 if (!strcmp(id, "cpu"))
435 return &cpu_clk;
436 if (!strcmp(id, "dsp"))
437 return &dsp_clk;
438 if (!strcmp(id, "vbus"))
439 return &vbus_clk;
440 return ERR_PTR(-ENOENT);
441 }
442 EXPORT_SYMBOL(clk_get);
443
clk_put(struct clk * clk)444 void clk_put(struct clk *clk)
445 {
446 }
447 EXPORT_SYMBOL(clk_put);
448
ar7_init_clocks(void)449 void __init ar7_init_clocks(void)
450 {
451 switch (ar7_chip_id()) {
452 case AR7_CHIP_7100:
453 case AR7_CHIP_7200:
454 tnetd7200_init_clocks();
455 break;
456 case AR7_CHIP_7300:
457 dsp_clk.rate = tnetd7300_dsp_clock();
458 tnetd7300_init_clocks();
459 break;
460 default:
461 break;
462 }
463 /* adjust vbus clock rate */
464 vbus_clk.rate = bus_clk.rate / 2;
465 }
466
467 /* dummy functions, should not be called */
clk_round_rate(struct clk * clk,unsigned long rate)468 long clk_round_rate(struct clk *clk, unsigned long rate)
469 {
470 WARN_ON(clk);
471 return 0;
472 }
473 EXPORT_SYMBOL(clk_round_rate);
474
clk_set_rate(struct clk * clk,unsigned long rate)475 int clk_set_rate(struct clk *clk, unsigned long rate)
476 {
477 WARN_ON(clk);
478 return 0;
479 }
480 EXPORT_SYMBOL(clk_set_rate);
481
clk_set_parent(struct clk * clk,struct clk * parent)482 int clk_set_parent(struct clk *clk, struct clk *parent)
483 {
484 WARN_ON(clk);
485 return 0;
486 }
487 EXPORT_SYMBOL(clk_set_parent);
488
clk_get_parent(struct clk * clk)489 struct clk *clk_get_parent(struct clk *clk)
490 {
491 WARN_ON(clk);
492 return NULL;
493 }
494 EXPORT_SYMBOL(clk_get_parent);
495