xref: /openbmc/linux/arch/mips/ar7/clock.c (revision 9b68f30b)
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/clkdev.h>
17 #include <linux/clk.h>
18 #include <linux/clk-provider.h>
19 
20 #include <asm/addrspace.h>
21 #include <asm/mach-ar7/ar7.h>
22 
23 #define BOOT_PLL_SOURCE_MASK	0x3
24 #define CPU_PLL_SOURCE_SHIFT	16
25 #define BUS_PLL_SOURCE_SHIFT	14
26 #define USB_PLL_SOURCE_SHIFT	18
27 #define DSP_PLL_SOURCE_SHIFT	22
28 #define BOOT_PLL_SOURCE_AFE	0
29 #define BOOT_PLL_SOURCE_BUS	0
30 #define BOOT_PLL_SOURCE_REF	1
31 #define BOOT_PLL_SOURCE_XTAL	2
32 #define BOOT_PLL_SOURCE_CPU	3
33 #define BOOT_PLL_BYPASS		0x00000020
34 #define BOOT_PLL_ASYNC_MODE	0x02000000
35 #define BOOT_PLL_2TO1_MODE	0x00008000
36 
37 #define TNETD7200_CLOCK_ID_CPU	0
38 #define TNETD7200_CLOCK_ID_DSP	1
39 #define TNETD7200_CLOCK_ID_USB	2
40 
41 #define TNETD7200_DEF_CPU_CLK	211000000
42 #define TNETD7200_DEF_DSP_CLK	125000000
43 #define TNETD7200_DEF_USB_CLK	48000000
44 
45 struct tnetd7300_clock {
46 	u32 ctrl;
47 #define PREDIV_MASK	0x001f0000
48 #define PREDIV_SHIFT	16
49 #define POSTDIV_MASK	0x0000001f
50 	u32 unused1[3];
51 	u32 pll;
52 #define MUL_MASK	0x0000f000
53 #define MUL_SHIFT	12
54 #define PLL_MODE_MASK	0x00000001
55 #define PLL_NDIV	0x00000800
56 #define PLL_DIV		0x00000002
57 #define PLL_STATUS	0x00000001
58 	u32 unused2[3];
59 };
60 
61 struct tnetd7300_clocks {
62 	struct tnetd7300_clock bus;
63 	struct tnetd7300_clock cpu;
64 	struct tnetd7300_clock usb;
65 	struct tnetd7300_clock dsp;
66 };
67 
68 struct tnetd7200_clock {
69 	u32 ctrl;
70 	u32 unused1[3];
71 #define DIVISOR_ENABLE_MASK 0x00008000
72 	u32 mul;
73 	u32 prediv;
74 	u32 postdiv;
75 	u32 postdiv2;
76 	u32 unused2[6];
77 	u32 cmd;
78 	u32 status;
79 	u32 cmden;
80 	u32 padding[15];
81 };
82 
83 struct tnetd7200_clocks {
84 	struct tnetd7200_clock cpu;
85 	struct tnetd7200_clock dsp;
86 	struct tnetd7200_clock usb;
87 };
88 
89 struct clk_rate {
90 	u32 rate;
91 };
92 static struct clk_rate bus_clk = {
93 	.rate	= 125000000,
94 };
95 
96 static struct clk_rate cpu_clk = {
97 	.rate	= 150000000,
98 };
99 
100 static void approximate(int base, int target, int *prediv,
101 			int *postdiv, int *mul)
102 {
103 	int i, j, k, freq, res = target;
104 	for (i = 1; i <= 16; i++)
105 		for (j = 1; j <= 32; j++)
106 			for (k = 1; k <= 32; k++) {
107 				freq = abs(base / j * i / k - target);
108 				if (freq < res) {
109 					res = freq;
110 					*mul = i;
111 					*prediv = j;
112 					*postdiv = k;
113 				}
114 			}
115 }
116 
117 static void calculate(int base, int target, int *prediv, int *postdiv,
118 	int *mul)
119 {
120 	int tmp_gcd, tmp_base, tmp_freq;
121 
122 	for (*prediv = 1; *prediv <= 32; (*prediv)++) {
123 		tmp_base = base / *prediv;
124 		tmp_gcd = gcd(target, tmp_base);
125 		*mul = target / tmp_gcd;
126 		*postdiv = tmp_base / tmp_gcd;
127 		if ((*mul < 1) || (*mul >= 16))
128 			continue;
129 		if ((*postdiv > 0) & (*postdiv <= 32))
130 			break;
131 	}
132 
133 	if (base / *prediv * *mul / *postdiv != target) {
134 		approximate(base, target, prediv, postdiv, mul);
135 		tmp_freq = base / *prediv * *mul / *postdiv;
136 		printk(KERN_WARNING
137 		       "Adjusted requested frequency %d to %d\n",
138 		       target, tmp_freq);
139 	}
140 
141 	printk(KERN_DEBUG "Clocks: prediv: %d, postdiv: %d, mul: %d\n",
142 	       *prediv, *postdiv, *mul);
143 }
144 
145 static int tnetd7300_dsp_clock(void)
146 {
147 	u32 didr1, didr2;
148 	u8 rev = ar7_chip_rev();
149 	didr1 = readl((void *)KSEG1ADDR(AR7_REGS_GPIO + 0x18));
150 	didr2 = readl((void *)KSEG1ADDR(AR7_REGS_GPIO + 0x1c));
151 	if (didr2 & (1 << 23))
152 		return 0;
153 	if ((rev >= 0x23) && (rev != 0x57))
154 		return 250000000;
155 	if ((((didr2 & 0x1fff) << 10) | ((didr1 & 0xffc00000) >> 22))
156 	    > 4208000)
157 		return 250000000;
158 	return 0;
159 }
160 
161 static int tnetd7300_get_clock(u32 shift, struct tnetd7300_clock *clock,
162 	u32 *bootcr, u32 bus_clock)
163 {
164 	int product;
165 	int base_clock = AR7_REF_CLOCK;
166 	u32 ctrl = readl(&clock->ctrl);
167 	u32 pll = readl(&clock->pll);
168 	int prediv = ((ctrl & PREDIV_MASK) >> PREDIV_SHIFT) + 1;
169 	int postdiv = (ctrl & POSTDIV_MASK) + 1;
170 	int divisor = prediv * postdiv;
171 	int mul = ((pll & MUL_MASK) >> MUL_SHIFT) + 1;
172 
173 	switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
174 	case BOOT_PLL_SOURCE_BUS:
175 		base_clock = bus_clock;
176 		break;
177 	case BOOT_PLL_SOURCE_REF:
178 		base_clock = AR7_REF_CLOCK;
179 		break;
180 	case BOOT_PLL_SOURCE_XTAL:
181 		base_clock = AR7_XTAL_CLOCK;
182 		break;
183 	case BOOT_PLL_SOURCE_CPU:
184 		base_clock = cpu_clk.rate;
185 		break;
186 	}
187 
188 	if (*bootcr & BOOT_PLL_BYPASS)
189 		return base_clock / divisor;
190 
191 	if ((pll & PLL_MODE_MASK) == 0)
192 		return (base_clock >> (mul / 16 + 1)) / divisor;
193 
194 	if ((pll & (PLL_NDIV | PLL_DIV)) == (PLL_NDIV | PLL_DIV)) {
195 		product = (mul & 1) ?
196 			(base_clock * mul) >> 1 :
197 			(base_clock * (mul - 1)) >> 2;
198 		return product / divisor;
199 	}
200 
201 	if (mul == 16)
202 		return base_clock / divisor;
203 
204 	return base_clock * mul / divisor;
205 }
206 
207 static void tnetd7300_set_clock(u32 shift, struct tnetd7300_clock *clock,
208 	u32 *bootcr, u32 frequency)
209 {
210 	int prediv, postdiv, mul;
211 	int base_clock = bus_clk.rate;
212 
213 	switch ((*bootcr & (BOOT_PLL_SOURCE_MASK << shift)) >> shift) {
214 	case BOOT_PLL_SOURCE_BUS:
215 		base_clock = bus_clk.rate;
216 		break;
217 	case BOOT_PLL_SOURCE_REF:
218 		base_clock = AR7_REF_CLOCK;
219 		break;
220 	case BOOT_PLL_SOURCE_XTAL:
221 		base_clock = AR7_XTAL_CLOCK;
222 		break;
223 	case BOOT_PLL_SOURCE_CPU:
224 		base_clock = cpu_clk.rate;
225 		break;
226 	}
227 
228 	calculate(base_clock, frequency, &prediv, &postdiv, &mul);
229 
230 	writel(((prediv - 1) << PREDIV_SHIFT) | (postdiv - 1), &clock->ctrl);
231 	mdelay(1);
232 	writel(4, &clock->pll);
233 	while (readl(&clock->pll) & PLL_STATUS)
234 		;
235 	writel(((mul - 1) << MUL_SHIFT) | (0xff << 3) | 0x0e, &clock->pll);
236 	mdelay(75);
237 }
238 
239 static void __init tnetd7300_init_clocks(void)
240 {
241 	u32 *bootcr = (u32 *)ioremap(AR7_REGS_DCL, 4);
242 	struct tnetd7300_clocks *clocks =
243 					ioremap(UR8_REGS_CLOCKS,
244 					sizeof(struct tnetd7300_clocks));
245 	u32 dsp_clk;
246 	struct clk *clk;
247 
248 	bus_clk.rate = tnetd7300_get_clock(BUS_PLL_SOURCE_SHIFT,
249 		&clocks->bus, bootcr, AR7_AFE_CLOCK);
250 
251 	if (*bootcr & BOOT_PLL_ASYNC_MODE)
252 		cpu_clk.rate = tnetd7300_get_clock(CPU_PLL_SOURCE_SHIFT,
253 			&clocks->cpu, bootcr, AR7_AFE_CLOCK);
254 	else
255 		cpu_clk.rate = bus_clk.rate;
256 
257 	dsp_clk = tnetd7300_dsp_clock();
258 	if (dsp_clk == 250000000)
259 		tnetd7300_set_clock(DSP_PLL_SOURCE_SHIFT, &clocks->dsp,
260 			bootcr, dsp_clk);
261 
262 	iounmap(clocks);
263 	iounmap(bootcr);
264 
265 	clk = clk_register_fixed_rate(NULL, "cpu", NULL, 0, cpu_clk.rate);
266 	clkdev_create(clk, "cpu", NULL);
267 	clk = clk_register_fixed_rate(NULL, "dsp", NULL, 0, dsp_clk);
268 	clkdev_create(clk, "dsp", NULL);
269 }
270 
271 static void tnetd7200_set_clock(int base, struct tnetd7200_clock *clock,
272 	int prediv, int postdiv, int postdiv2, int mul, u32 frequency)
273 {
274 	printk(KERN_INFO
275 		"Clocks: base = %d, frequency = %u, prediv = %d, "
276 		"postdiv = %d, postdiv2 = %d, mul = %d\n",
277 		base, frequency, prediv, postdiv, postdiv2, mul);
278 
279 	writel(0, &clock->ctrl);
280 	writel(DIVISOR_ENABLE_MASK | ((prediv - 1) & 0x1F), &clock->prediv);
281 	writel((mul - 1) & 0xF, &clock->mul);
282 
283 	while (readl(&clock->status) & 0x1)
284 		; /* nop */
285 
286 	writel(DIVISOR_ENABLE_MASK | ((postdiv - 1) & 0x1F), &clock->postdiv);
287 
288 	writel(readl(&clock->cmden) | 1, &clock->cmden);
289 	writel(readl(&clock->cmd) | 1, &clock->cmd);
290 
291 	while (readl(&clock->status) & 0x1)
292 		; /* nop */
293 
294 	writel(DIVISOR_ENABLE_MASK | ((postdiv2 - 1) & 0x1F), &clock->postdiv2);
295 
296 	writel(readl(&clock->cmden) | 1, &clock->cmden);
297 	writel(readl(&clock->cmd) | 1, &clock->cmd);
298 
299 	while (readl(&clock->status) & 0x1)
300 		; /* nop */
301 
302 	writel(readl(&clock->ctrl) | 1, &clock->ctrl);
303 }
304 
305 static int tnetd7200_get_clock_base(int clock_id, u32 *bootcr)
306 {
307 	if (*bootcr & BOOT_PLL_ASYNC_MODE)
308 		/* Async */
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 		/* Sync */
317 		if (*bootcr & BOOT_PLL_2TO1_MODE)
318 			/* 2:1 */
319 			switch (clock_id) {
320 			case TNETD7200_CLOCK_ID_DSP:
321 				return AR7_REF_CLOCK;
322 			default:
323 				return AR7_AFE_CLOCK;
324 			}
325 		else
326 			/* 1:1 */
327 			return AR7_REF_CLOCK;
328 }
329 
330 
331 static void __init tnetd7200_init_clocks(void)
332 {
333 	u32 *bootcr = (u32 *)ioremap(AR7_REGS_DCL, 4);
334 	struct tnetd7200_clocks *clocks =
335 					ioremap(AR7_REGS_CLOCKS,
336 					sizeof(struct tnetd7200_clocks));
337 	int cpu_base, cpu_mul, cpu_prediv, cpu_postdiv;
338 	int dsp_base, dsp_mul, dsp_prediv, dsp_postdiv;
339 	int usb_base, usb_mul, usb_prediv, usb_postdiv;
340 	struct clk *clk;
341 
342 	cpu_base = tnetd7200_get_clock_base(TNETD7200_CLOCK_ID_CPU, bootcr);
343 	dsp_base = tnetd7200_get_clock_base(TNETD7200_CLOCK_ID_DSP, bootcr);
344 
345 	if (*bootcr & BOOT_PLL_ASYNC_MODE) {
346 		printk(KERN_INFO "Clocks: Async mode\n");
347 
348 		printk(KERN_INFO "Clocks: Setting DSP clock\n");
349 		calculate(dsp_base, TNETD7200_DEF_DSP_CLK,
350 			&dsp_prediv, &dsp_postdiv, &dsp_mul);
351 		bus_clk.rate =
352 			((dsp_base / dsp_prediv) * dsp_mul) / dsp_postdiv;
353 		tnetd7200_set_clock(dsp_base, &clocks->dsp,
354 			dsp_prediv, dsp_postdiv * 2, dsp_postdiv, dsp_mul * 2,
355 			bus_clk.rate);
356 
357 		printk(KERN_INFO "Clocks: Setting CPU clock\n");
358 		calculate(cpu_base, TNETD7200_DEF_CPU_CLK, &cpu_prediv,
359 			&cpu_postdiv, &cpu_mul);
360 		cpu_clk.rate =
361 			((cpu_base / cpu_prediv) * cpu_mul) / cpu_postdiv;
362 		tnetd7200_set_clock(cpu_base, &clocks->cpu,
363 			cpu_prediv, cpu_postdiv, -1, cpu_mul,
364 			cpu_clk.rate);
365 
366 	} else
367 		if (*bootcr & BOOT_PLL_2TO1_MODE) {
368 			printk(KERN_INFO "Clocks: Sync 2:1 mode\n");
369 
370 			printk(KERN_INFO "Clocks: Setting CPU clock\n");
371 			calculate(cpu_base, TNETD7200_DEF_CPU_CLK, &cpu_prediv,
372 				&cpu_postdiv, &cpu_mul);
373 			cpu_clk.rate = ((cpu_base / cpu_prediv) * cpu_mul)
374 								/ cpu_postdiv;
375 			tnetd7200_set_clock(cpu_base, &clocks->cpu,
376 				cpu_prediv, cpu_postdiv, -1, cpu_mul,
377 				cpu_clk.rate);
378 
379 			printk(KERN_INFO "Clocks: Setting DSP clock\n");
380 			calculate(dsp_base, TNETD7200_DEF_DSP_CLK, &dsp_prediv,
381 				&dsp_postdiv, &dsp_mul);
382 			bus_clk.rate = cpu_clk.rate / 2;
383 			tnetd7200_set_clock(dsp_base, &clocks->dsp,
384 				dsp_prediv, dsp_postdiv * 2, dsp_postdiv,
385 				dsp_mul * 2, bus_clk.rate);
386 		} else {
387 			printk(KERN_INFO "Clocks: Sync 1:1 mode\n");
388 
389 			printk(KERN_INFO "Clocks: Setting DSP clock\n");
390 			calculate(dsp_base, TNETD7200_DEF_DSP_CLK, &dsp_prediv,
391 				&dsp_postdiv, &dsp_mul);
392 			bus_clk.rate = ((dsp_base / dsp_prediv) * dsp_mul)
393 								/ dsp_postdiv;
394 			tnetd7200_set_clock(dsp_base, &clocks->dsp,
395 				dsp_prediv, dsp_postdiv * 2, dsp_postdiv,
396 				dsp_mul * 2, bus_clk.rate);
397 
398 			cpu_clk.rate = bus_clk.rate;
399 		}
400 
401 	printk(KERN_INFO "Clocks: Setting USB clock\n");
402 	usb_base = bus_clk.rate;
403 	calculate(usb_base, TNETD7200_DEF_USB_CLK, &usb_prediv,
404 		&usb_postdiv, &usb_mul);
405 	tnetd7200_set_clock(usb_base, &clocks->usb,
406 		usb_prediv, usb_postdiv, -1, usb_mul,
407 		TNETD7200_DEF_USB_CLK);
408 
409 	iounmap(clocks);
410 	iounmap(bootcr);
411 
412 	clk = clk_register_fixed_rate(NULL, "cpu", NULL, 0, cpu_clk.rate);
413 	clkdev_create(clk, "cpu", NULL);
414 	clkdev_create(clk, "dsp", NULL);
415 }
416 
417 void __init ar7_init_clocks(void)
418 {
419 	struct clk *clk;
420 
421 	switch (ar7_chip_id()) {
422 	case AR7_CHIP_7100:
423 	case AR7_CHIP_7200:
424 		tnetd7200_init_clocks();
425 		break;
426 	case AR7_CHIP_7300:
427 		tnetd7300_init_clocks();
428 		break;
429 	default:
430 		break;
431 	}
432 	clk = clk_register_fixed_rate(NULL, "bus", NULL, 0, bus_clk.rate);
433 	clkdev_create(clk, "bus", NULL);
434 	/* adjust vbus clock rate */
435 	clk = clk_register_fixed_factor(NULL, "vbus", "bus", 0, 1, 2);
436 	clkdev_create(clk, "vbus", NULL);
437 	clkdev_create(clk, "cpmac", "cpmac.1");
438 	clkdev_create(clk, "cpmac", "cpmac.1");
439 }
440