1 /*
2 * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
3 * Copyright (C) 2007 Eugene Konev <ejka@openwrt.org>
4 * Copyright (C) 2009 Florian Fainelli <florian@openwrt.org>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21 #include <linux/kernel.h>
22 #include <linux/init.h>
23 #include <linux/types.h>
24 #include <linux/module.h>
25 #include <linux/delay.h>
26 #include <linux/gcd.h>
27 #include <linux/io.h>
28 #include <linux/err.h>
29 #include <linux/clk.h>
30
31 #include <asm/addrspace.h>
32 #include <asm/mach-ar7/ar7.h>
33
34 #define BOOT_PLL_SOURCE_MASK 0x3
35 #define CPU_PLL_SOURCE_SHIFT 16
36 #define BUS_PLL_SOURCE_SHIFT 14
37 #define USB_PLL_SOURCE_SHIFT 18
38 #define DSP_PLL_SOURCE_SHIFT 22
39 #define BOOT_PLL_SOURCE_AFE 0
40 #define BOOT_PLL_SOURCE_BUS 0
41 #define BOOT_PLL_SOURCE_REF 1
42 #define BOOT_PLL_SOURCE_XTAL 2
43 #define BOOT_PLL_SOURCE_CPU 3
44 #define BOOT_PLL_BYPASS 0x00000020
45 #define BOOT_PLL_ASYNC_MODE 0x02000000
46 #define BOOT_PLL_2TO1_MODE 0x00008000
47
48 #define TNETD7200_CLOCK_ID_CPU 0
49 #define TNETD7200_CLOCK_ID_DSP 1
50 #define TNETD7200_CLOCK_ID_USB 2
51
52 #define TNETD7200_DEF_CPU_CLK 211000000
53 #define TNETD7200_DEF_DSP_CLK 125000000
54 #define TNETD7200_DEF_USB_CLK 48000000
55
56 struct tnetd7300_clock {
57 u32 ctrl;
58 #define PREDIV_MASK 0x001f0000
59 #define PREDIV_SHIFT 16
60 #define POSTDIV_MASK 0x0000001f
61 u32 unused1[3];
62 u32 pll;
63 #define MUL_MASK 0x0000f000
64 #define MUL_SHIFT 12
65 #define PLL_MODE_MASK 0x00000001
66 #define PLL_NDIV 0x00000800
67 #define PLL_DIV 0x00000002
68 #define PLL_STATUS 0x00000001
69 u32 unused2[3];
70 };
71
72 struct tnetd7300_clocks {
73 struct tnetd7300_clock bus;
74 struct tnetd7300_clock cpu;
75 struct tnetd7300_clock usb;
76 struct tnetd7300_clock dsp;
77 };
78
79 struct tnetd7200_clock {
80 u32 ctrl;
81 u32 unused1[3];
82 #define DIVISOR_ENABLE_MASK 0x00008000
83 u32 mul;
84 u32 prediv;
85 u32 postdiv;
86 u32 postdiv2;
87 u32 unused2[6];
88 u32 cmd;
89 u32 status;
90 u32 cmden;
91 u32 padding[15];
92 };
93
94 struct tnetd7200_clocks {
95 struct tnetd7200_clock cpu;
96 struct tnetd7200_clock dsp;
97 struct tnetd7200_clock usb;
98 };
99
100 static struct clk bus_clk = {
101 .rate = 125000000,
102 };
103
104 static struct clk cpu_clk = {
105 .rate = 150000000,
106 };
107
108 static struct clk dsp_clk;
109 static struct clk vbus_clk;
110
approximate(int base,int target,int * prediv,int * postdiv,int * mul)111 static void approximate(int base, int target, int *prediv,
112 int *postdiv, int *mul)
113 {
114 int i, j, k, freq, res = target;
115 for (i = 1; i <= 16; i++)
116 for (j = 1; j <= 32; j++)
117 for (k = 1; k <= 32; k++) {
118 freq = abs(base / j * i / k - target);
119 if (freq < res) {
120 res = freq;
121 *mul = i;
122 *prediv = j;
123 *postdiv = k;
124 }
125 }
126 }
127
calculate(int base,int target,int * prediv,int * postdiv,int * mul)128 static void calculate(int base, int target, int *prediv, int *postdiv,
129 int *mul)
130 {
131 int tmp_gcd, tmp_base, tmp_freq;
132
133 for (*prediv = 1; *prediv <= 32; (*prediv)++) {
134 tmp_base = base / *prediv;
135 tmp_gcd = gcd(target, tmp_base);
136 *mul = target / tmp_gcd;
137 *postdiv = tmp_base / tmp_gcd;
138 if ((*mul < 1) || (*mul >= 16))
139 continue;
140 if ((*postdiv > 0) & (*postdiv <= 32))
141 break;
142 }
143
144 if (base / *prediv * *mul / *postdiv != target) {
145 approximate(base, target, prediv, postdiv, mul);
146 tmp_freq = base / *prediv * *mul / *postdiv;
147 printk(KERN_WARNING
148 "Adjusted requested frequency %d to %d\n",
149 target, tmp_freq);
150 }
151
152 printk(KERN_DEBUG "Clocks: prediv: %d, postdiv: %d, mul: %d\n",
153 *prediv, *postdiv, *mul);
154 }
155
tnetd7300_dsp_clock(void)156 static int tnetd7300_dsp_clock(void)
157 {
158 u32 didr1, didr2;
159 u8 rev = ar7_chip_rev();
160 didr1 = readl((void *)KSEG1ADDR(AR7_REGS_GPIO + 0x18));
161 didr2 = readl((void *)KSEG1ADDR(AR7_REGS_GPIO + 0x1c));
162 if (didr2 & (1 << 23))
163 return 0;
164 if ((rev >= 0x23) && (rev != 0x57))
165 return 250000000;
166 if ((((didr2 & 0x1fff) << 10) | ((didr1 & 0xffc00000) >> 22))
167 > 4208000)
168 return 250000000;
169 return 0;
170 }
171
tnetd7300_get_clock(u32 shift,struct tnetd7300_clock * clock,u32 * bootcr,u32 bus_clock)172 static int tnetd7300_get_clock(u32 shift, struct tnetd7300_clock *clock,
173 u32 *bootcr, u32 bus_clock)
174 {
175 int product;
176 int base_clock = AR7_REF_CLOCK;
177 u32 ctrl = readl(&clock->ctrl);
178 u32 pll = readl(&clock->pll);
179 int prediv = ((ctrl & PREDIV_MASK) >> PREDIV_SHIFT) + 1;
180 int postdiv = (ctrl & POSTDIV_MASK) + 1;
181 int divisor = prediv * postdiv;
182 int mul = ((pll & MUL_MASK) >> MUL_SHIFT) + 1;
183
184 switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
185 case BOOT_PLL_SOURCE_BUS:
186 base_clock = bus_clock;
187 break;
188 case BOOT_PLL_SOURCE_REF:
189 base_clock = AR7_REF_CLOCK;
190 break;
191 case BOOT_PLL_SOURCE_XTAL:
192 base_clock = AR7_XTAL_CLOCK;
193 break;
194 case BOOT_PLL_SOURCE_CPU:
195 base_clock = cpu_clk.rate;
196 break;
197 }
198
199 if (*bootcr & BOOT_PLL_BYPASS)
200 return base_clock / divisor;
201
202 if ((pll & PLL_MODE_MASK) == 0)
203 return (base_clock >> (mul / 16 + 1)) / divisor;
204
205 if ((pll & (PLL_NDIV | PLL_DIV)) == (PLL_NDIV | PLL_DIV)) {
206 product = (mul & 1) ?
207 (base_clock * mul) >> 1 :
208 (base_clock * (mul - 1)) >> 2;
209 return product / divisor;
210 }
211
212 if (mul == 16)
213 return base_clock / divisor;
214
215 return base_clock * mul / divisor;
216 }
217
tnetd7300_set_clock(u32 shift,struct tnetd7300_clock * clock,u32 * bootcr,u32 frequency)218 static void tnetd7300_set_clock(u32 shift, struct tnetd7300_clock *clock,
219 u32 *bootcr, u32 frequency)
220 {
221 int prediv, postdiv, mul;
222 int base_clock = bus_clk.rate;
223
224 switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
225 case BOOT_PLL_SOURCE_BUS:
226 base_clock = bus_clk.rate;
227 break;
228 case BOOT_PLL_SOURCE_REF:
229 base_clock = AR7_REF_CLOCK;
230 break;
231 case BOOT_PLL_SOURCE_XTAL:
232 base_clock = AR7_XTAL_CLOCK;
233 break;
234 case BOOT_PLL_SOURCE_CPU:
235 base_clock = cpu_clk.rate;
236 break;
237 }
238
239 calculate(base_clock, frequency, &prediv, &postdiv, &mul);
240
241 writel(((prediv - 1) << PREDIV_SHIFT) | (postdiv - 1), &clock->ctrl);
242 mdelay(1);
243 writel(4, &clock->pll);
244 while (readl(&clock->pll) & PLL_STATUS)
245 ;
246 writel(((mul - 1) << MUL_SHIFT) | (0xff << 3) | 0x0e, &clock->pll);
247 mdelay(75);
248 }
249
tnetd7300_init_clocks(void)250 static void __init tnetd7300_init_clocks(void)
251 {
252 u32 *bootcr = (u32 *)ioremap_nocache(AR7_REGS_DCL, 4);
253 struct tnetd7300_clocks *clocks =
254 ioremap_nocache(UR8_REGS_CLOCKS,
255 sizeof(struct tnetd7300_clocks));
256
257 bus_clk.rate = tnetd7300_get_clock(BUS_PLL_SOURCE_SHIFT,
258 &clocks->bus, bootcr, AR7_AFE_CLOCK);
259
260 if (*bootcr & BOOT_PLL_ASYNC_MODE)
261 cpu_clk.rate = tnetd7300_get_clock(CPU_PLL_SOURCE_SHIFT,
262 &clocks->cpu, bootcr, AR7_AFE_CLOCK);
263 else
264 cpu_clk.rate = bus_clk.rate;
265
266 if (dsp_clk.rate == 250000000)
267 tnetd7300_set_clock(DSP_PLL_SOURCE_SHIFT, &clocks->dsp,
268 bootcr, dsp_clk.rate);
269
270 iounmap(clocks);
271 iounmap(bootcr);
272 }
273
tnetd7200_set_clock(int base,struct tnetd7200_clock * clock,int prediv,int postdiv,int postdiv2,int mul,u32 frequency)274 static void tnetd7200_set_clock(int base, struct tnetd7200_clock *clock,
275 int prediv, int postdiv, int postdiv2, int mul, u32 frequency)
276 {
277 printk(KERN_INFO
278 "Clocks: base = %d, frequency = %u, prediv = %d, "
279 "postdiv = %d, postdiv2 = %d, mul = %d\n",
280 base, frequency, prediv, postdiv, postdiv2, mul);
281
282 writel(0, &clock->ctrl);
283 writel(DIVISOR_ENABLE_MASK | ((prediv - 1) & 0x1F), &clock->prediv);
284 writel((mul - 1) & 0xF, &clock->mul);
285
286 while (readl(&clock->status) & 0x1)
287 ; /* nop */
288
289 writel(DIVISOR_ENABLE_MASK | ((postdiv - 1) & 0x1F), &clock->postdiv);
290
291 writel(readl(&clock->cmden) | 1, &clock->cmden);
292 writel(readl(&clock->cmd) | 1, &clock->cmd);
293
294 while (readl(&clock->status) & 0x1)
295 ; /* nop */
296
297 writel(DIVISOR_ENABLE_MASK | ((postdiv2 - 1) & 0x1F), &clock->postdiv2);
298
299 writel(readl(&clock->cmden) | 1, &clock->cmden);
300 writel(readl(&clock->cmd) | 1, &clock->cmd);
301
302 while (readl(&clock->status) & 0x1)
303 ; /* nop */
304
305 writel(readl(&clock->ctrl) | 1, &clock->ctrl);
306 }
307
tnetd7200_get_clock_base(int clock_id,u32 * bootcr)308 static int tnetd7200_get_clock_base(int clock_id, u32 *bootcr)
309 {
310 if (*bootcr & BOOT_PLL_ASYNC_MODE)
311 /* Async */
312 switch (clock_id) {
313 case TNETD7200_CLOCK_ID_DSP:
314 return AR7_REF_CLOCK;
315 default:
316 return AR7_AFE_CLOCK;
317 }
318 else
319 /* Sync */
320 if (*bootcr & BOOT_PLL_2TO1_MODE)
321 /* 2:1 */
322 switch (clock_id) {
323 case TNETD7200_CLOCK_ID_DSP:
324 return AR7_REF_CLOCK;
325 default:
326 return AR7_AFE_CLOCK;
327 }
328 else
329 /* 1:1 */
330 return AR7_REF_CLOCK;
331 }
332
333
tnetd7200_init_clocks(void)334 static void __init tnetd7200_init_clocks(void)
335 {
336 u32 *bootcr = (u32 *)ioremap_nocache(AR7_REGS_DCL, 4);
337 struct tnetd7200_clocks *clocks =
338 ioremap_nocache(AR7_REGS_CLOCKS,
339 sizeof(struct tnetd7200_clocks));
340 int cpu_base, cpu_mul, cpu_prediv, cpu_postdiv;
341 int dsp_base, dsp_mul, dsp_prediv, dsp_postdiv;
342 int usb_base, usb_mul, usb_prediv, usb_postdiv;
343
344 cpu_base = tnetd7200_get_clock_base(TNETD7200_CLOCK_ID_CPU, bootcr);
345 dsp_base = tnetd7200_get_clock_base(TNETD7200_CLOCK_ID_DSP, bootcr);
346
347 if (*bootcr & BOOT_PLL_ASYNC_MODE) {
348 printk(KERN_INFO "Clocks: Async mode\n");
349
350 printk(KERN_INFO "Clocks: Setting DSP clock\n");
351 calculate(dsp_base, TNETD7200_DEF_DSP_CLK,
352 &dsp_prediv, &dsp_postdiv, &dsp_mul);
353 bus_clk.rate =
354 ((dsp_base / dsp_prediv) * dsp_mul) / dsp_postdiv;
355 tnetd7200_set_clock(dsp_base, &clocks->dsp,
356 dsp_prediv, dsp_postdiv * 2, dsp_postdiv, dsp_mul * 2,
357 bus_clk.rate);
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 =
363 ((cpu_base / cpu_prediv) * cpu_mul) / cpu_postdiv;
364 tnetd7200_set_clock(cpu_base, &clocks->cpu,
365 cpu_prediv, cpu_postdiv, -1, cpu_mul,
366 cpu_clk.rate);
367
368 } else
369 if (*bootcr & BOOT_PLL_2TO1_MODE) {
370 printk(KERN_INFO "Clocks: Sync 2:1 mode\n");
371
372 printk(KERN_INFO "Clocks: Setting CPU clock\n");
373 calculate(cpu_base, TNETD7200_DEF_CPU_CLK, &cpu_prediv,
374 &cpu_postdiv, &cpu_mul);
375 cpu_clk.rate = ((cpu_base / cpu_prediv) * cpu_mul)
376 / cpu_postdiv;
377 tnetd7200_set_clock(cpu_base, &clocks->cpu,
378 cpu_prediv, cpu_postdiv, -1, cpu_mul,
379 cpu_clk.rate);
380
381 printk(KERN_INFO "Clocks: Setting DSP clock\n");
382 calculate(dsp_base, TNETD7200_DEF_DSP_CLK, &dsp_prediv,
383 &dsp_postdiv, &dsp_mul);
384 bus_clk.rate = cpu_clk.rate / 2;
385 tnetd7200_set_clock(dsp_base, &clocks->dsp,
386 dsp_prediv, dsp_postdiv * 2, dsp_postdiv,
387 dsp_mul * 2, bus_clk.rate);
388 } else {
389 printk(KERN_INFO "Clocks: Sync 1:1 mode\n");
390
391 printk(KERN_INFO "Clocks: Setting DSP clock\n");
392 calculate(dsp_base, TNETD7200_DEF_DSP_CLK, &dsp_prediv,
393 &dsp_postdiv, &dsp_mul);
394 bus_clk.rate = ((dsp_base / dsp_prediv) * dsp_mul)
395 / dsp_postdiv;
396 tnetd7200_set_clock(dsp_base, &clocks->dsp,
397 dsp_prediv, dsp_postdiv * 2, dsp_postdiv,
398 dsp_mul * 2, bus_clk.rate);
399
400 cpu_clk.rate = bus_clk.rate;
401 }
402
403 printk(KERN_INFO "Clocks: Setting USB clock\n");
404 usb_base = bus_clk.rate;
405 calculate(usb_base, TNETD7200_DEF_USB_CLK, &usb_prediv,
406 &usb_postdiv, &usb_mul);
407 tnetd7200_set_clock(usb_base, &clocks->usb,
408 usb_prediv, usb_postdiv, -1, usb_mul,
409 TNETD7200_DEF_USB_CLK);
410
411 dsp_clk.rate = cpu_clk.rate;
412
413 iounmap(clocks);
414 iounmap(bootcr);
415 }
416
417 /*
418 * Linux clock API
419 */
clk_enable(struct clk * clk)420 int clk_enable(struct clk *clk)
421 {
422 return 0;
423 }
424 EXPORT_SYMBOL(clk_enable);
425
clk_disable(struct clk * clk)426 void clk_disable(struct clk *clk)
427 {
428 }
429 EXPORT_SYMBOL(clk_disable);
430
clk_get_rate(struct clk * clk)431 unsigned long clk_get_rate(struct clk *clk)
432 {
433 return clk->rate;
434 }
435 EXPORT_SYMBOL(clk_get_rate);
436
clk_get(struct device * dev,const char * id)437 struct clk *clk_get(struct device *dev, const char *id)
438 {
439 if (!strcmp(id, "bus"))
440 return &bus_clk;
441 /* cpmac and vbus share the same rate */
442 if (!strcmp(id, "cpmac"))
443 return &vbus_clk;
444 if (!strcmp(id, "cpu"))
445 return &cpu_clk;
446 if (!strcmp(id, "dsp"));
447 return &dsp_clk;
448 if (!strcmp(id, "vbus"))
449 return &vbus_clk;
450 return ERR_PTR(-ENOENT);
451 }
452 EXPORT_SYMBOL(clk_get);
453
clk_put(struct clk * clk)454 void clk_put(struct clk *clk)
455 {
456 }
457 EXPORT_SYMBOL(clk_put);
458
ar7_init_clocks(void)459 void __init ar7_init_clocks(void)
460 {
461 switch (ar7_chip_id()) {
462 case AR7_CHIP_7100:
463 case AR7_CHIP_7200:
464 tnetd7200_init_clocks();
465 break;
466 case AR7_CHIP_7300:
467 dsp_clk.rate = tnetd7300_dsp_clock();
468 tnetd7300_init_clocks();
469 break;
470 default:
471 break;
472 }
473 /* adjust vbus clock rate */
474 vbus_clk.rate = bus_clk.rate / 2;
475 }
476