xref: /openbmc/u-boot/drivers/clk/aspeed/clk_ast2600.c (revision d6e349c734ff075fa91c8a4213c6fbc95469a19f)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) ASPEED Technology Inc.
4  * Ryan Chen <ryan_chen@aspeedtech.com>
5  */
6 
7 #include <common.h>
8 #include <clk-uclass.h>
9 #include <dm.h>
10 #include <asm/io.h>
11 #include <asm/arch/scu_aspeed.h>
12 #include <dm/lists.h>
13 #include <dt-bindings/clock/ast2600-clock.h>
14 
15 /* register */
16 #define ASPEED_STRAP		0x70
17 #define SCU_HWSTRAP_VGAMEM_SHIFT	2
18 #define SCU_HWSTRAP_VGAMEM_MASK		(3 << SCU_HWSTRAP_VGAMEM_SHIFT)
19 #define SCU_HWSTRAP_MAC1_RGMII		(1 << 6)
20 #define SCU_HWSTRAP_MAC2_RGMII		(1 << 7)
21 #define SCU_HWSTRAP_DDR4		(1 << 24)
22 #define SCU_HWSTRAP_CLKIN_25MHZ		(1 << 23)
23 
24 #define ASPEED_CLK_SELECT	0x08
25 #define SCU_PCLK_DIV_SHIFT		23
26 #define SCU_PCLK_DIV_MASK		(7 << SCU_PCLK_DIV_SHIFT)
27 
28 #define ASPEED_MSIC2		0x4C
29 #define SCU_MISC2_RGMII_HPLL		(1 << 23)
30 #define SCU_MISC2_RGMII_CLKDIV_SHIFT	20
31 #define SCU_MISC2_RGMII_CLKDIV_MASK	(3 << SCU_MISC2_RGMII_CLKDIV_SHIFT)
32 #define SCU_MISC2_RMII_MPLL		(1 << 19)
33 #define SCU_MISC2_RMII_CLKDIV_SHIFT	16
34 #define SCU_MISC2_RMII_CLKDIV_MASK	(3 << SCU_MISC2_RMII_CLKDIV_SHIFT)
35 #define SCU_MISC2_UARTCLK_SHIFT		24
36 
37 #define ASPEED_MPLL_PARAMETER	0x20
38 #define SCU_MPLL_DENUM_SHIFT		0
39 #define SCU_MPLL_DENUM_MASK		0x1f
40 #define SCU_MPLL_NUM_SHIFT		5
41 #define SCU_MPLL_NUM_MASK		(0xff << SCU_MPLL_NUM_SHIFT)
42 #define SCU_MPLL_POST_SHIFT		13
43 #define SCU_MPLL_POST_MASK		(0x3f << SCU_MPLL_POST_SHIFT)
44 
45 #define ASPEED_HPLL_PARAMETER	0x24
46 #define SCU_HPLL_DENUM_SHIFT		0
47 #define SCU_HPLL_DENUM_MASK		0x1f
48 #define SCU_HPLL_NUM_SHIFT		5
49 #define SCU_HPLL_NUM_MASK		(0xff << SCU_HPLL_NUM_SHIFT)
50 #define SCU_HPLL_POST_SHIFT		13
51 #define SCU_HPLL_POST_MASK		(0x3f << SCU_HPLL_POST_SHIFT)
52 
53 
54 /*
55  * MAC Clock Delay settings, taken from Aspeed SDK
56  */
57 #define RGMII_TXCLK_ODLY		8
58 #define RMII_RXCLK_IDLY		2
59 
60 /*
61  * TGMII Clock Duty constants, taken from Aspeed SDK
62  */
63 #define RGMII2_TXCK_DUTY	0x66
64 #define RGMII1_TXCK_DUTY	0x64
65 
66 #define D2PLL_DEFAULT_RATE	(250 * 1000 * 1000)
67 
68 DECLARE_GLOBAL_DATA_PTR;
69 
70 /*
71  * Clock divider/multiplier configuration struct.
72  * For H-PLL and M-PLL the formula is
73  * (Output Frequency) = CLKIN * ((M + 1) / (N + 1)) / (P + 1)
74  * M - Numerator
75  * N - Denumerator
76  * P - Post Divider
77  * They have the same layout in their control register.
78  *
79  * D-PLL and D2-PLL have extra divider (OD + 1), which is not
80  * yet needed and ignored by clock configurations.
81  */
82 struct aspeed_div_config {
83 	unsigned int num;
84 	unsigned int denum;
85 	unsigned int post_div;
86 };
87 
88 #define AST2600_CLK_IN	25000000
89 
90 /*
91  * Get the rate of the M-PLL clock from input clock frequency and
92  * the value of the M-PLL Parameter Register.
93  */
94 static u32 aspeed_get_mpll_rate(struct aspeed_clk_priv *priv)
95 {
96 	u32 clkin = AST2600_CLK_IN;
97 	u32 mpll_reg = readl(priv->regs + ASPEED_MPLL_PARAMETER);
98 
99 	const ulong num = (mpll_reg & SCU_MPLL_NUM_MASK) >> SCU_MPLL_NUM_SHIFT;
100 	const ulong denum = (mpll_reg & SCU_MPLL_DENUM_MASK)
101 			>> SCU_MPLL_DENUM_SHIFT;
102 	const ulong post_div = (mpll_reg & SCU_MPLL_POST_MASK)
103 			>> SCU_MPLL_POST_SHIFT;
104 
105 	return (clkin * ((num + 1) / (denum + 1))) / (post_div + 1);
106 }
107 
108 /*
109  * Get the rate of the H-PLL clock from input clock frequency and
110  * the value of the H-PLL Parameter Register.
111  */
112 static ulong aspeed_get_hpll_rate(struct aspeed_clk_priv *priv)
113 {
114 	ulong clkin = AST2600_CLK_IN;
115 	u32 hpll_reg = readl(priv->regs + ASPEED_HPLL_PARAMETER);
116 	const ulong num = (hpll_reg & SCU_HPLL_NUM_MASK) >> SCU_HPLL_NUM_SHIFT;
117 	const ulong denum = (hpll_reg & SCU_HPLL_DENUM_MASK)
118 			>> SCU_HPLL_DENUM_SHIFT;
119 	const ulong post_div = (hpll_reg & SCU_HPLL_POST_MASK)
120 			>> SCU_HPLL_POST_SHIFT;
121 
122 	return (clkin * ((num + 1) / (denum + 1))) / (post_div + 1);
123 }
124 
125 
126 #define ASPEED_G6_APLL_PARAMETER	0x210
127 #define APLL_BYPASS_EN	BIT(20)
128 
129 static ulong ast2600_get_apll_clk_rate(struct aspeed_clk_priv *priv)
130 {
131 	u32 clk_in = 25000000;
132 	u32 val = readl(priv->regs + ASPEED_G6_APLL_PARAMETER);
133 
134 
135 	unsigned int mult, div;
136 
137 	if (val & APLL_BYPASS_EN) {
138 		/* Pass through mode */
139 		mult = div = 1;
140 	} else {
141 		/* F = 25Mhz * (2-OD) * [(M + 2) / (n + 1)] */
142 		u32 m = (val >> 5) & 0x3f;
143 		u32 od = (val >> 4) & 0x1;
144 		u32 n = val & 0xf;
145 
146 		mult = (2 - od) * (m + 2);
147 		div = n + 1;
148 	}
149 	return (clk_in * mult)/div;
150 
151 
152 
153 }
154 
155 #define ASPEED_G6_CLK_SELECT4		0x314
156 
157 static ulong ast2600_get_uart_clk_rate(struct aspeed_clk_priv *priv, int uart_index)
158 {
159 	ulong uart_clkin;
160 
161 	printf("ast2600_get_uart_clk_rate source %d \n\n", ast2600_get_apll_clk_rate(priv));
162 	return (24000000/13);
163 
164 	if (readl(priv->regs + ASPEED_MSIC2) &
165 	    (1 << (uart_index - 1 + SCU_MISC2_UARTCLK_SHIFT)))
166 		uart_clkin = 192 * 1000 * 1000;
167 	else
168 		uart_clkin = 24 * 1000 * 1000;
169 
170 	if (readl(priv->regs + ASPEED_MSIC2) & SCU_MISC_UARTCLK_DIV13)
171 		uart_clkin /= 13;
172 
173 	return uart_clkin;
174 }
175 
176 struct aspeed_clock_config {
177 	ulong input_rate;
178 	ulong rate;
179 	struct aspeed_div_config cfg;
180 };
181 
182 static const struct aspeed_clock_config aspeed_clock_config_defaults[] = {
183 	{ 24000000, 250000000, { .num = 124, .denum = 1, .post_div = 5 } },
184 };
185 
186 static bool aspeed_get_clock_config_default(ulong input_rate,
187 					     ulong requested_rate,
188 					     struct aspeed_div_config *cfg)
189 {
190 	int i;
191 
192 	for (i = 0; i < ARRAY_SIZE(aspeed_clock_config_defaults); i++) {
193 		const struct aspeed_clock_config *default_cfg =
194 			&aspeed_clock_config_defaults[i];
195 		if (default_cfg->input_rate == input_rate &&
196 		    default_cfg->rate == requested_rate) {
197 			*cfg = default_cfg->cfg;
198 			return true;
199 		}
200 	}
201 
202 	return false;
203 }
204 
205 /*
206  * @input_rate - the rate of input clock in Hz
207  * @requested_rate - desired output rate in Hz
208  * @div - this is an IN/OUT parameter, at input all fields of the config
209  * need to be set to their maximum allowed values.
210  * The result (the best config we could find), would also be returned
211  * in this structure.
212  *
213  * @return The clock rate, when the resulting div_config is used.
214  */
215 static ulong aspeed_calc_clock_config(ulong input_rate, ulong requested_rate,
216 				       struct aspeed_div_config *cfg)
217 {
218 	/*
219 	 * The assumption is that kHz precision is good enough and
220 	 * also enough to avoid overflow when multiplying.
221 	 */
222 	const ulong input_rate_khz = input_rate / 1000;
223 	const ulong rate_khz = requested_rate / 1000;
224 	const struct aspeed_div_config max_vals = *cfg;
225 	struct aspeed_div_config it = { 0, 0, 0 };
226 	ulong delta = rate_khz;
227 	ulong new_rate_khz = 0;
228 
229 	/*
230 	 * Look for a well known frequency first.
231 	 */
232 	if (aspeed_get_clock_config_default(input_rate, requested_rate, cfg))
233 		return requested_rate;
234 
235 	for (; it.denum <= max_vals.denum; ++it.denum) {
236 		for (it.post_div = 0; it.post_div <= max_vals.post_div;
237 		     ++it.post_div) {
238 			it.num = (rate_khz * (it.post_div + 1) / input_rate_khz)
239 			    * (it.denum + 1);
240 			if (it.num > max_vals.num)
241 				continue;
242 
243 			new_rate_khz = (input_rate_khz
244 					* ((it.num + 1) / (it.denum + 1)))
245 			    / (it.post_div + 1);
246 
247 			/* Keep the rate below requested one. */
248 			if (new_rate_khz > rate_khz)
249 				continue;
250 
251 			if (new_rate_khz - rate_khz < delta) {
252 				delta = new_rate_khz - rate_khz;
253 				*cfg = it;
254 				if (delta == 0)
255 					return new_rate_khz * 1000;
256 			}
257 		}
258 	}
259 
260 	return new_rate_khz * 1000;
261 }
262 
263 static u32 aspeed_configure_ddr(struct aspeed_clk_priv *priv, ulong rate)
264 {
265 	u32 clkin = AST2600_CLK_IN;
266 	u32 mpll_reg;
267 	struct aspeed_div_config div_cfg = {
268 		.num = (SCU_MPLL_NUM_MASK >> SCU_MPLL_NUM_SHIFT),
269 		.denum = (SCU_MPLL_DENUM_MASK >> SCU_MPLL_DENUM_SHIFT),
270 		.post_div = (SCU_MPLL_POST_MASK >> SCU_MPLL_POST_SHIFT),
271 	};
272 
273 	aspeed_calc_clock_config(clkin, rate, &div_cfg);
274 
275 	mpll_reg = readl(priv->regs + ASPEED_MPLL_PARAMETER);
276 	mpll_reg &= ~(SCU_MPLL_POST_MASK | SCU_MPLL_NUM_MASK
277 		      | SCU_MPLL_DENUM_MASK);
278 	mpll_reg |= (div_cfg.post_div << SCU_MPLL_POST_SHIFT)
279 	    | (div_cfg.num << SCU_MPLL_NUM_SHIFT)
280 	    | (div_cfg.denum << SCU_MPLL_DENUM_SHIFT);
281 
282 	writel(mpll_reg, priv->regs + ASPEED_MPLL_PARAMETER);
283 
284 	return aspeed_get_mpll_rate(priv);
285 }
286 
287 static u32 aspeed_configure_mac(struct aspeed_clk_priv *priv, int index)
288 {
289 	u32 clkin = AST2600_CLK_IN;
290 	u32 hpll_rate = aspeed_get_hpll_rate(priv);
291 	ulong required_rate;
292 	u32 hwstrap;
293 	u32 divisor;
294 	u32 reset_bit;
295 	u32 clkstop_bit;
296 #if 0
297 	/*
298 	 * According to data sheet, for 10/100 mode the MAC clock frequency
299 	 * should be at least 25MHz and for 1000 mode at least 100MHz
300 	 */
301 	hwstrap = readl(priv->regs + ASPEED_STRAP);
302 	if (hwstrap & (SCU_HWSTRAP_MAC1_RGMII | SCU_HWSTRAP_MAC2_RGMII))
303 		required_rate = 100 * 1000 * 1000;
304 	else
305 		required_rate = 25 * 1000 * 1000;
306 
307 	divisor = hpll_rate / required_rate;
308 
309 	if (divisor < 4) {
310 		/* Clock can't run fast enough, but let's try anyway */
311 		debug("MAC clock too slow\n");
312 		divisor = 4;
313 	} else if (divisor > 16) {
314 		/* Can't slow down the clock enough, but let's try anyway */
315 		debug("MAC clock too fast\n");
316 		divisor = 16;
317 	}
318 
319 	switch (index) {
320 	case 1:
321 		reset_bit = SCU_SYSRESET_MAC1;
322 		clkstop_bit = SCU_CLKSTOP_MAC1;
323 		break;
324 	case 2:
325 		reset_bit = SCU_SYSRESET_MAC2;
326 		clkstop_bit = SCU_CLKSTOP_MAC2;
327 		break;
328 	default:
329 		return -EINVAL;
330 	}
331 
332 	clrsetbits_le32(priv->regs + ASPEED_CLK_SELECT, SCU_MACCLK_MASK,
333 			((divisor - 2) / 2) << SCU_MACCLK_SHIFT);
334 
335 	/*
336 	 * Disable MAC, start its clock and re-enable it.
337 	 * The procedure and the delays (100us & 10ms) are
338 	 * specified in the datasheet.
339 	 */
340 	setbits_le32(&scu->sysreset_ctrl1, reset_bit);
341 	udelay(100);
342 	clrbits_le32(&scu->clk_stop_ctrl1, clkstop_bit);
343 	mdelay(10);
344 	clrbits_le32(&scu->sysreset_ctrl1, reset_bit);
345 
346 	writel((RGMII2_TXCK_DUTY << SCU_CLKDUTY_RGMII2TXCK_SHIFT)
347 	       | (RGMII1_TXCK_DUTY << SCU_CLKDUTY_RGMII1TXCK_SHIFT),
348 	       &scu->clk_duty_sel);
349 #endif
350 	return required_rate;
351 }
352 
353 static ulong aspeed_configure_d2pll(struct aspeed_clk_priv *priv, ulong rate)
354 {
355 	/*
356 	 * The values and the meaning of the next three
357 	 * parameters are undocumented. Taken from Aspeed SDK.
358 	 *
359 	 * TODO(clg@kaod.org): the SIP and SIC values depend on the
360 	 * Numerator value
361 	 */
362 
363 	const u32 d2_pll_ext_param = 0x2c;
364 	const u32 d2_pll_sip = 0x11;
365 	const u32 d2_pll_sic = 0x18;
366 	u32 clk_delay_settings =
367 	    (RMII_RXCLK_IDLY << SCU_MICDS_MAC1RMII_RDLY_SHIFT)
368 	    | (RMII_RXCLK_IDLY << SCU_MICDS_MAC2RMII_RDLY_SHIFT)
369 	    | (RGMII_TXCLK_ODLY << SCU_MICDS_MAC1RGMII_TXDLY_SHIFT)
370 	    | (RGMII_TXCLK_ODLY << SCU_MICDS_MAC2RGMII_TXDLY_SHIFT);
371 	struct aspeed_div_config div_cfg = {
372 		.num = SCU_D2PLL_NUM_MASK >> SCU_D2PLL_NUM_SHIFT,
373 		.denum = SCU_D2PLL_DENUM_MASK >> SCU_D2PLL_DENUM_SHIFT,
374 		.post_div = SCU_D2PLL_POST_MASK >> SCU_D2PLL_POST_SHIFT,
375 	};
376 	ulong clkin = AST2600_CLK_IN;
377 	ulong new_rate;
378 #if 0
379 	writel((d2_pll_ext_param << SCU_D2PLL_EXT1_PARAM_SHIFT)
380 	       | SCU_D2PLL_EXT1_OFF
381 	       | SCU_D2PLL_EXT1_RESET, &scu->d2_pll_ext_param[0]);
382 
383 	/*
384 	 * Select USB2.0 port1 PHY clock as a clock source for GCRT.
385 	 * This would disconnect it from D2-PLL.
386 	 */
387 	clrsetbits_le32(&scu->misc_ctrl1, SCU_MISC_D2PLL_OFF,
388 			SCU_MISC_GCRT_USB20CLK);
389 
390 	new_rate = aspeed_calc_clock_config(clkin, rate, &div_cfg);
391 	writel((d2_pll_sip << SCU_D2PLL_SIP_SHIFT)
392 	       | (d2_pll_sic << SCU_D2PLL_SIC_SHIFT)
393 	       | (div_cfg.num << SCU_D2PLL_NUM_SHIFT)
394 	       | (div_cfg.denum << SCU_D2PLL_DENUM_SHIFT)
395 	       | (div_cfg.post_div << SCU_D2PLL_POST_SHIFT),
396 	       &scu->d2_pll_param);
397 
398 	clrbits_le32(&scu->d2_pll_ext_param[0],
399 		     SCU_D2PLL_EXT1_OFF | SCU_D2PLL_EXT1_RESET);
400 
401 	clrsetbits_le32(&scu->misc_ctrl2,
402 			SCU_MISC2_RGMII_HPLL | SCU_MISC2_RMII_MPLL
403 			| SCU_MISC2_RGMII_CLKDIV_MASK |
404 			SCU_MISC2_RMII_CLKDIV_MASK,
405 			(4 << SCU_MISC2_RMII_CLKDIV_SHIFT));
406 
407 	writel(clk_delay_settings | SCU_MICDS_RGMIIPLL, &scu->mac_clk_delay);
408 	writel(clk_delay_settings, &scu->mac_clk_delay_100M);
409 	writel(clk_delay_settings, &scu->mac_clk_delay_10M);
410 #endif
411 	return new_rate;
412 }
413 
414 static ulong ast2600_clk_get_rate(struct clk *clk)
415 {
416 	struct aspeed_clk_priv *priv = dev_get_priv(clk->dev);
417 	ulong rate;
418 
419 	switch (clk->id) {
420 	case PLL_HPLL:
421 	case ARMCLK:
422 		/*
423 		 * This ignores dynamic/static slowdown of ARMCLK and may
424 		 * be inaccurate.
425 		 */
426 		rate = aspeed_get_hpll_rate(priv);
427 
428 		break;
429 	case MCLK_DDR:
430 		rate = aspeed_get_mpll_rate(priv);
431 		break;
432 	case BCLK_PCLK:
433 		{
434 			ulong apb_div = 4 + 4 * ((readl(priv->regs + ASPEED_CLK_SELECT)
435 						  & SCU_PCLK_DIV_MASK)
436 						 >> SCU_PCLK_DIV_SHIFT);
437 			rate = aspeed_get_hpll_rate(priv);
438 			rate = rate / apb_div;
439 		}
440 		break;
441 	case BCLK_HCLK:
442 		rate = aspeed_get_hpll_rate(priv);
443 		break;
444 	case PCLK_UART1:
445 		rate = ast2600_get_uart_clk_rate(priv, 1);
446 		break;
447 	case PCLK_UART2:
448 		rate = ast2600_get_uart_clk_rate(priv, 2);
449 		break;
450 	case PCLK_UART3:
451 		rate = ast2600_get_uart_clk_rate(priv, 3);
452 		break;
453 	case PCLK_UART4:
454 		rate = ast2600_get_uart_clk_rate(priv, 4);
455 		break;
456 	case ASPEED_CLK_UART5:
457 		rate = ast2600_get_uart_clk_rate(priv, 5);
458 		break;
459 	default:
460 		return -ENOENT;
461 	}
462 
463 	return rate;
464 }
465 
466 static ulong ast2600_clk_set_rate(struct clk *clk, ulong rate)
467 {
468 	struct aspeed_clk_priv *priv = dev_get_priv(clk->dev);
469 
470 	ulong new_rate;
471 	switch (clk->id) {
472 	case PLL_MPLL:
473 	case MCLK_DDR:
474 		new_rate = aspeed_configure_ddr(priv, rate);
475 		break;
476 	case PLL_D2PLL:
477 		new_rate = aspeed_configure_d2pll(priv, rate);
478 		break;
479 	default:
480 		return -ENOENT;
481 	}
482 
483 	return new_rate;
484 }
485 
486 static int ast2600_clk_enable(struct clk *clk)
487 {
488 	struct aspeed_clk_priv *priv = dev_get_priv(clk->dev);
489 
490 	switch (clk->id) {
491 	/*
492 	 * For MAC clocks the clock rate is
493 	 * configured based on whether RGMII or RMII mode has been selected
494 	 * through hardware strapping.
495 	 */
496 	case PCLK_MAC1:
497 		aspeed_configure_mac(priv, 1);
498 		break;
499 	case PCLK_MAC2:
500 		aspeed_configure_mac(priv, 2);
501 		break;
502 	case PLL_D2PLL:
503 		aspeed_configure_d2pll(priv, D2PLL_DEFAULT_RATE);
504 		break;
505 	default:
506 		return -ENOENT;
507 	}
508 
509 	return 0;
510 }
511 
512 struct clk_ops aspeed_clk_ops = {
513 	.get_rate = ast2600_clk_get_rate,
514 	.set_rate = ast2600_clk_set_rate,
515 	.enable = ast2600_clk_enable,
516 };
517 
518 static int ast2600_clk_probe(struct udevice *dev)
519 {
520 	struct aspeed_clk_priv *priv = dev_get_priv(dev);
521 
522 	priv->regs = devfdt_get_addr_ptr(dev);
523 
524 	if (IS_ERR(priv->regs))
525 		return PTR_ERR(priv->regs);
526 
527 	priv->version = dev_get_driver_data(dev);
528 
529 	return 0;
530 }
531 
532 static int ast2600_clk_bind(struct udevice *dev)
533 {
534 	int ret;
535 
536 	/* The reset driver does not have a device node, so bind it here */
537 	ret = device_bind_driver(gd->dm_root, "ast_sysreset", "reset", &dev);
538 	if (ret)
539 		debug("Warning: No reset driver: ret=%d\n", ret);
540 
541 	return 0;
542 }
543 
544 static const struct udevice_id ast2600_clk_ids[] = {
545 	{ .compatible = "aspeed,ast2600-scu", },
546 	{ }
547 };
548 
549 U_BOOT_DRIVER(aspeed_scu) = {
550 	.name		= "aspeed_scu",
551 	.id		= UCLASS_CLK,
552 	.of_match	= ast2600_clk_ids,
553 	.priv_auto_alloc_size = sizeof(struct aspeed_clk_priv),
554 	.ops		= &aspeed_clk_ops,
555 	.bind		= ast2600_clk_bind,
556 	.probe		= ast2600_clk_probe,
557 };
558