xref: /openbmc/linux/arch/mips/ar7/clock.c (revision a09d2831)
1 /*
2  * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
3  * Copyright (C) 2007 Eugene Konev <ejka@openwrt.org>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
18  */
19 
20 #include <linux/kernel.h>
21 #include <linux/init.h>
22 #include <linux/types.h>
23 #include <linux/module.h>
24 #include <linux/delay.h>
25 #include <linux/gcd.h>
26 #include <linux/io.h>
27 
28 #include <asm/addrspace.h>
29 #include <asm/mach-ar7/ar7.h>
30 
31 #define BOOT_PLL_SOURCE_MASK	0x3
32 #define CPU_PLL_SOURCE_SHIFT	16
33 #define BUS_PLL_SOURCE_SHIFT	14
34 #define USB_PLL_SOURCE_SHIFT	18
35 #define DSP_PLL_SOURCE_SHIFT	22
36 #define BOOT_PLL_SOURCE_AFE	0
37 #define BOOT_PLL_SOURCE_BUS	0
38 #define BOOT_PLL_SOURCE_REF	1
39 #define BOOT_PLL_SOURCE_XTAL	2
40 #define BOOT_PLL_SOURCE_CPU	3
41 #define BOOT_PLL_BYPASS		0x00000020
42 #define BOOT_PLL_ASYNC_MODE	0x02000000
43 #define BOOT_PLL_2TO1_MODE	0x00008000
44 
45 #define TNETD7200_CLOCK_ID_CPU	0
46 #define TNETD7200_CLOCK_ID_DSP	1
47 #define TNETD7200_CLOCK_ID_USB	2
48 
49 #define TNETD7200_DEF_CPU_CLK	211000000
50 #define TNETD7200_DEF_DSP_CLK	125000000
51 #define TNETD7200_DEF_USB_CLK	48000000
52 
53 struct tnetd7300_clock {
54 	u32 ctrl;
55 #define PREDIV_MASK	0x001f0000
56 #define PREDIV_SHIFT	16
57 #define POSTDIV_MASK	0x0000001f
58 	u32 unused1[3];
59 	u32 pll;
60 #define MUL_MASK	0x0000f000
61 #define MUL_SHIFT	12
62 #define PLL_MODE_MASK	0x00000001
63 #define PLL_NDIV	0x00000800
64 #define PLL_DIV		0x00000002
65 #define PLL_STATUS	0x00000001
66 	u32 unused2[3];
67 };
68 
69 struct tnetd7300_clocks {
70 	struct tnetd7300_clock bus;
71 	struct tnetd7300_clock cpu;
72 	struct tnetd7300_clock usb;
73 	struct tnetd7300_clock dsp;
74 };
75 
76 struct tnetd7200_clock {
77 	u32 ctrl;
78 	u32 unused1[3];
79 #define DIVISOR_ENABLE_MASK 0x00008000
80 	u32 mul;
81 	u32 prediv;
82 	u32 postdiv;
83 	u32 postdiv2;
84 	u32 unused2[6];
85 	u32 cmd;
86 	u32 status;
87 	u32 cmden;
88 	u32 padding[15];
89 };
90 
91 struct tnetd7200_clocks {
92 	struct tnetd7200_clock cpu;
93 	struct tnetd7200_clock dsp;
94 	struct tnetd7200_clock usb;
95 };
96 
97 int ar7_cpu_clock = 150000000;
98 EXPORT_SYMBOL(ar7_cpu_clock);
99 int ar7_bus_clock = 125000000;
100 EXPORT_SYMBOL(ar7_bus_clock);
101 int ar7_dsp_clock;
102 EXPORT_SYMBOL(ar7_dsp_clock);
103 
104 static void approximate(int base, int target, int *prediv,
105 			int *postdiv, int *mul)
106 {
107 	int i, j, k, freq, res = target;
108 	for (i = 1; i <= 16; i++)
109 		for (j = 1; j <= 32; j++)
110 			for (k = 1; k <= 32; k++) {
111 				freq = abs(base / j * i / k - target);
112 				if (freq < res) {
113 					res = freq;
114 					*mul = i;
115 					*prediv = j;
116 					*postdiv = k;
117 				}
118 			}
119 }
120 
121 static void calculate(int base, int target, int *prediv, int *postdiv,
122 	int *mul)
123 {
124 	int tmp_gcd, tmp_base, tmp_freq;
125 
126 	for (*prediv = 1; *prediv <= 32; (*prediv)++) {
127 		tmp_base = base / *prediv;
128 		tmp_gcd = gcd(target, tmp_base);
129 		*mul = target / tmp_gcd;
130 		*postdiv = tmp_base / tmp_gcd;
131 		if ((*mul < 1) || (*mul >= 16))
132 			continue;
133 		if ((*postdiv > 0) & (*postdiv <= 32))
134 			break;
135 	}
136 
137 	if (base / *prediv * *mul / *postdiv != target) {
138 		approximate(base, target, prediv, postdiv, mul);
139 		tmp_freq = base / *prediv * *mul / *postdiv;
140 		printk(KERN_WARNING
141 		       "Adjusted requested frequency %d to %d\n",
142 		       target, tmp_freq);
143 	}
144 
145 	printk(KERN_DEBUG "Clocks: prediv: %d, postdiv: %d, mul: %d\n",
146 	       *prediv, *postdiv, *mul);
147 }
148 
149 static int tnetd7300_dsp_clock(void)
150 {
151 	u32 didr1, didr2;
152 	u8 rev = ar7_chip_rev();
153 	didr1 = readl((void *)KSEG1ADDR(AR7_REGS_GPIO + 0x18));
154 	didr2 = readl((void *)KSEG1ADDR(AR7_REGS_GPIO + 0x1c));
155 	if (didr2 & (1 << 23))
156 		return 0;
157 	if ((rev >= 0x23) && (rev != 0x57))
158 		return 250000000;
159 	if ((((didr2 & 0x1fff) << 10) | ((didr1 & 0xffc00000) >> 22))
160 	    > 4208000)
161 		return 250000000;
162 	return 0;
163 }
164 
165 static int tnetd7300_get_clock(u32 shift, struct tnetd7300_clock *clock,
166 	u32 *bootcr, u32 bus_clock)
167 {
168 	int product;
169 	int base_clock = AR7_REF_CLOCK;
170 	u32 ctrl = readl(&clock->ctrl);
171 	u32 pll = readl(&clock->pll);
172 	int prediv = ((ctrl & PREDIV_MASK) >> PREDIV_SHIFT) + 1;
173 	int postdiv = (ctrl & POSTDIV_MASK) + 1;
174 	int divisor = prediv * postdiv;
175 	int mul = ((pll & MUL_MASK) >> MUL_SHIFT) + 1;
176 
177 	switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
178 	case BOOT_PLL_SOURCE_BUS:
179 		base_clock = bus_clock;
180 		break;
181 	case BOOT_PLL_SOURCE_REF:
182 		base_clock = AR7_REF_CLOCK;
183 		break;
184 	case BOOT_PLL_SOURCE_XTAL:
185 		base_clock = AR7_XTAL_CLOCK;
186 		break;
187 	case BOOT_PLL_SOURCE_CPU:
188 		base_clock = ar7_cpu_clock;
189 		break;
190 	}
191 
192 	if (*bootcr & BOOT_PLL_BYPASS)
193 		return base_clock / divisor;
194 
195 	if ((pll & PLL_MODE_MASK) == 0)
196 		return (base_clock >> (mul / 16 + 1)) / divisor;
197 
198 	if ((pll & (PLL_NDIV | PLL_DIV)) == (PLL_NDIV | PLL_DIV)) {
199 		product = (mul & 1) ?
200 			(base_clock * mul) >> 1 :
201 			(base_clock * (mul - 1)) >> 2;
202 		return product / divisor;
203 	}
204 
205 	if (mul == 16)
206 		return base_clock / divisor;
207 
208 	return base_clock * mul / divisor;
209 }
210 
211 static void tnetd7300_set_clock(u32 shift, struct tnetd7300_clock *clock,
212 	u32 *bootcr, u32 frequency)
213 {
214 	int prediv, postdiv, mul;
215 	int base_clock = ar7_bus_clock;
216 
217 	switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
218 	case BOOT_PLL_SOURCE_BUS:
219 		base_clock = ar7_bus_clock;
220 		break;
221 	case BOOT_PLL_SOURCE_REF:
222 		base_clock = AR7_REF_CLOCK;
223 		break;
224 	case BOOT_PLL_SOURCE_XTAL:
225 		base_clock = AR7_XTAL_CLOCK;
226 		break;
227 	case BOOT_PLL_SOURCE_CPU:
228 		base_clock = ar7_cpu_clock;
229 		break;
230 	}
231 
232 	calculate(base_clock, frequency, &prediv, &postdiv, &mul);
233 
234 	writel(((prediv - 1) << PREDIV_SHIFT) | (postdiv - 1), &clock->ctrl);
235 	msleep(1);
236 	writel(4, &clock->pll);
237 	while (readl(&clock->pll) & PLL_STATUS)
238 		;
239 	writel(((mul - 1) << MUL_SHIFT) | (0xff << 3) | 0x0e, &clock->pll);
240 	msleep(75);
241 }
242 
243 static void __init tnetd7300_init_clocks(void)
244 {
245 	u32 *bootcr = (u32 *)ioremap_nocache(AR7_REGS_DCL, 4);
246 	struct tnetd7300_clocks *clocks =
247 					ioremap_nocache(UR8_REGS_CLOCKS,
248 					sizeof(struct tnetd7300_clocks));
249 
250 	ar7_bus_clock = tnetd7300_get_clock(BUS_PLL_SOURCE_SHIFT,
251 		&clocks->bus, bootcr, AR7_AFE_CLOCK);
252 
253 	if (*bootcr & BOOT_PLL_ASYNC_MODE)
254 		ar7_cpu_clock = tnetd7300_get_clock(CPU_PLL_SOURCE_SHIFT,
255 			&clocks->cpu, bootcr, AR7_AFE_CLOCK);
256 	else
257 		ar7_cpu_clock = ar7_bus_clock;
258 
259 	if (ar7_dsp_clock == 250000000)
260 		tnetd7300_set_clock(DSP_PLL_SOURCE_SHIFT, &clocks->dsp,
261 			bootcr, ar7_dsp_clock);
262 
263 	iounmap(clocks);
264 	iounmap(bootcr);
265 }
266 
267 static void tnetd7200_set_clock(int base, struct tnetd7200_clock *clock,
268 	int prediv, int postdiv, int postdiv2, int mul, u32 frequency)
269 {
270 	printk(KERN_INFO
271 		"Clocks: base = %d, frequency = %u, prediv = %d, "
272 		"postdiv = %d, postdiv2 = %d, mul = %d\n",
273 		base, frequency, prediv, postdiv, postdiv2, mul);
274 
275 	writel(0, &clock->ctrl);
276 	writel(DIVISOR_ENABLE_MASK | ((prediv - 1) & 0x1F), &clock->prediv);
277 	writel((mul - 1) & 0xF, &clock->mul);
278 
279 	while (readl(&clock->status) & 0x1)
280 		; /* nop */
281 
282 	writel(DIVISOR_ENABLE_MASK | ((postdiv - 1) & 0x1F), &clock->postdiv);
283 
284 	writel(readl(&clock->cmden) | 1, &clock->cmden);
285 	writel(readl(&clock->cmd) | 1, &clock->cmd);
286 
287 	while (readl(&clock->status) & 0x1)
288 		; /* nop */
289 
290 	writel(DIVISOR_ENABLE_MASK | ((postdiv2 - 1) & 0x1F), &clock->postdiv2);
291 
292 	writel(readl(&clock->cmden) | 1, &clock->cmden);
293 	writel(readl(&clock->cmd) | 1, &clock->cmd);
294 
295 	while (readl(&clock->status) & 0x1)
296 		; /* nop */
297 
298 	writel(readl(&clock->ctrl) | 1, &clock->ctrl);
299 }
300 
301 static int tnetd7200_get_clock_base(int clock_id, u32 *bootcr)
302 {
303 	if (*bootcr & BOOT_PLL_ASYNC_MODE)
304 		/* Async */
305 		switch (clock_id) {
306 		case TNETD7200_CLOCK_ID_DSP:
307 			return AR7_REF_CLOCK;
308 		default:
309 			return AR7_AFE_CLOCK;
310 		}
311 	else
312 		/* Sync */
313 		if (*bootcr & BOOT_PLL_2TO1_MODE)
314 			/* 2:1 */
315 			switch (clock_id) {
316 			case TNETD7200_CLOCK_ID_DSP:
317 				return AR7_REF_CLOCK;
318 			default:
319 				return AR7_AFE_CLOCK;
320 			}
321 		else
322 			/* 1:1 */
323 			return AR7_REF_CLOCK;
324 }
325 
326 
327 static void __init tnetd7200_init_clocks(void)
328 {
329 	u32 *bootcr = (u32 *)ioremap_nocache(AR7_REGS_DCL, 4);
330 	struct tnetd7200_clocks *clocks =
331 					ioremap_nocache(AR7_REGS_CLOCKS,
332 					sizeof(struct tnetd7200_clocks));
333 	int cpu_base, cpu_mul, cpu_prediv, cpu_postdiv;
334 	int dsp_base, dsp_mul, dsp_prediv, dsp_postdiv;
335 	int usb_base, usb_mul, usb_prediv, usb_postdiv;
336 
337 	cpu_base = tnetd7200_get_clock_base(TNETD7200_CLOCK_ID_CPU, bootcr);
338 	dsp_base = tnetd7200_get_clock_base(TNETD7200_CLOCK_ID_DSP, bootcr);
339 
340 	if (*bootcr & BOOT_PLL_ASYNC_MODE) {
341 		printk(KERN_INFO "Clocks: Async mode\n");
342 
343 		printk(KERN_INFO "Clocks: Setting DSP clock\n");
344 		calculate(dsp_base, TNETD7200_DEF_DSP_CLK,
345 			&dsp_prediv, &dsp_postdiv, &dsp_mul);
346 		ar7_bus_clock =
347 			((dsp_base / dsp_prediv) * dsp_mul) / dsp_postdiv;
348 		tnetd7200_set_clock(dsp_base, &clocks->dsp,
349 			dsp_prediv, dsp_postdiv * 2, dsp_postdiv, dsp_mul * 2,
350 			ar7_bus_clock);
351 
352 		printk(KERN_INFO "Clocks: Setting CPU clock\n");
353 		calculate(cpu_base, TNETD7200_DEF_CPU_CLK, &cpu_prediv,
354 			&cpu_postdiv, &cpu_mul);
355 		ar7_cpu_clock =
356 			((cpu_base / cpu_prediv) * cpu_mul) / cpu_postdiv;
357 		tnetd7200_set_clock(cpu_base, &clocks->cpu,
358 			cpu_prediv, cpu_postdiv, -1, cpu_mul,
359 			ar7_cpu_clock);
360 
361 	} else
362 		if (*bootcr & BOOT_PLL_2TO1_MODE) {
363 			printk(KERN_INFO "Clocks: Sync 2:1 mode\n");
364 
365 			printk(KERN_INFO "Clocks: Setting CPU clock\n");
366 			calculate(cpu_base, TNETD7200_DEF_CPU_CLK, &cpu_prediv,
367 				&cpu_postdiv, &cpu_mul);
368 			ar7_cpu_clock = ((cpu_base / cpu_prediv) * cpu_mul)
369 								/ cpu_postdiv;
370 			tnetd7200_set_clock(cpu_base, &clocks->cpu,
371 				cpu_prediv, cpu_postdiv, -1, cpu_mul,
372 				ar7_cpu_clock);
373 
374 			printk(KERN_INFO "Clocks: Setting DSP clock\n");
375 			calculate(dsp_base, TNETD7200_DEF_DSP_CLK, &dsp_prediv,
376 				&dsp_postdiv, &dsp_mul);
377 			ar7_bus_clock = ar7_cpu_clock / 2;
378 			tnetd7200_set_clock(dsp_base, &clocks->dsp,
379 				dsp_prediv, dsp_postdiv * 2, dsp_postdiv,
380 				dsp_mul * 2, ar7_bus_clock);
381 		} else {
382 			printk(KERN_INFO "Clocks: Sync 1:1 mode\n");
383 
384 			printk(KERN_INFO "Clocks: Setting DSP clock\n");
385 			calculate(dsp_base, TNETD7200_DEF_DSP_CLK, &dsp_prediv,
386 				&dsp_postdiv, &dsp_mul);
387 			ar7_bus_clock = ((dsp_base / dsp_prediv) * dsp_mul)
388 								/ dsp_postdiv;
389 			tnetd7200_set_clock(dsp_base, &clocks->dsp,
390 				dsp_prediv, dsp_postdiv * 2, dsp_postdiv,
391 				dsp_mul * 2, ar7_bus_clock);
392 
393 			ar7_cpu_clock = ar7_bus_clock;
394 		}
395 
396 	printk(KERN_INFO "Clocks: Setting USB clock\n");
397 	usb_base = ar7_bus_clock;
398 	calculate(usb_base, TNETD7200_DEF_USB_CLK, &usb_prediv,
399 		&usb_postdiv, &usb_mul);
400 	tnetd7200_set_clock(usb_base, &clocks->usb,
401 		usb_prediv, usb_postdiv, -1, usb_mul,
402 		TNETD7200_DEF_USB_CLK);
403 
404 	ar7_dsp_clock = ar7_cpu_clock;
405 
406 	iounmap(clocks);
407 	iounmap(bootcr);
408 }
409 
410 int __init ar7_init_clocks(void)
411 {
412 	switch (ar7_chip_id()) {
413 	case AR7_CHIP_7100:
414 	case AR7_CHIP_7200:
415 		tnetd7200_init_clocks();
416 		break;
417 	case AR7_CHIP_7300:
418 		ar7_dsp_clock = tnetd7300_dsp_clock();
419 		tnetd7300_init_clocks();
420 		break;
421 	default:
422 		break;
423 	}
424 
425 	return 0;
426 }
427 arch_initcall(ar7_init_clocks);
428