xref: /openbmc/u-boot/drivers/clk/aspeed/clk_ast2600.c (revision 1eda014bf7497329d951c6eced4d98fdf6270f53)
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/ast2500-scu.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 static u32 aspeed_get_clkin(struct aspeed_clk_priv *priv)
89 {
90 	switch(priv->version) {
91 		case AST2400:
92 		case AST2500:
93 			return readl(priv->regs + ASPEED_STRAP) & SCU_HWSTRAP_CLKIN_25MHZ
94 					? 25 * 1000 * 1000 : 24 * 1000 * 1000;
95 			break;
96 		case AST2600:
97 			return 25000000;
98 			break;
99 	}
100 	return 0;
101 }
102 
103 /*
104  * Get the rate of the M-PLL clock from input clock frequency and
105  * the value of the M-PLL Parameter Register.
106  */
107 static u32 aspeed_get_mpll_rate(struct aspeed_clk_priv *priv)
108 {
109 	u32 clkin = aspeed_get_clkin(priv);
110 	u32 mpll_reg = readl(priv->regs + ASPEED_MPLL_PARAMETER);
111 
112 	const ulong num = (mpll_reg & SCU_MPLL_NUM_MASK) >> SCU_MPLL_NUM_SHIFT;
113 	const ulong denum = (mpll_reg & SCU_MPLL_DENUM_MASK)
114 			>> SCU_MPLL_DENUM_SHIFT;
115 	const ulong post_div = (mpll_reg & SCU_MPLL_POST_MASK)
116 			>> SCU_MPLL_POST_SHIFT;
117 
118 	return (clkin * ((num + 1) / (denum + 1))) / (post_div + 1);
119 }
120 
121 /*
122  * Get the rate of the H-PLL clock from input clock frequency and
123  * the value of the H-PLL Parameter Register.
124  */
125 static ulong aspeed_get_hpll_rate(struct aspeed_clk_priv *priv)
126 {
127 	ulong clkin = aspeed_get_clkin(priv);
128 	u32 hpll_reg = readl(priv->regs + ASPEED_HPLL_PARAMETER);
129 	const ulong num = (hpll_reg & SCU_HPLL_NUM_MASK) >> SCU_HPLL_NUM_SHIFT;
130 	const ulong denum = (hpll_reg & SCU_HPLL_DENUM_MASK)
131 			>> SCU_HPLL_DENUM_SHIFT;
132 	const ulong post_div = (hpll_reg & SCU_HPLL_POST_MASK)
133 			>> SCU_HPLL_POST_SHIFT;
134 
135 	return (clkin * ((num + 1) / (denum + 1))) / (post_div + 1);
136 }
137 
138 
139 /**
140  * Get current rate or uart clock
141  *
142  * @scu SCU registers
143  * @uart_index UART index, 1-5
144  *
145  * @return current setting for uart clock rate
146  */
147 static ulong aspeed_get_uart_clk_rate(struct aspeed_clk_priv *priv, int uart_index)
148 {
149 	/*
150 	 * ast2600 datasheet is very confusing when it comes to UART clocks,
151 	 * especially when CLKIN = 25 MHz. The settings are in
152 	 * different registers and it is unclear how they interact.
153 	 *
154 	 * This has only been tested with default settings and CLKIN = 24 MHz.
155 	 */
156 	ulong uart_clkin;
157 
158 	if (readl(priv->regs + ASPEED_MSIC2) &
159 	    (1 << (uart_index - 1 + SCU_MISC2_UARTCLK_SHIFT)))
160 		uart_clkin = 192 * 1000 * 1000;
161 	else
162 		uart_clkin = 24 * 1000 * 1000;
163 
164 	if (readl(priv->regs + ASPEED_MSIC2) & SCU_MISC_UARTCLK_DIV13)
165 		uart_clkin /= 13;
166 
167 	return uart_clkin;
168 }
169 
170 static ulong aspeed_clk_get_rate(struct clk *clk)
171 {
172 	struct aspeed_clk_priv *priv = dev_get_priv(clk->dev);
173 	ulong rate;
174 
175 	switch (clk->id) {
176 	case PLL_HPLL:
177 	case ARMCLK:
178 		/*
179 		 * This ignores dynamic/static slowdown of ARMCLK and may
180 		 * be inaccurate.
181 		 */
182 		rate = aspeed_get_hpll_rate(priv);
183 
184 		break;
185 	case MCLK_DDR:
186 		rate = aspeed_get_mpll_rate(priv);
187 		break;
188 	case BCLK_PCLK:
189 		{
190 			ulong apb_div = 4 + 4 * ((readl(priv->regs + ASPEED_CLK_SELECT)
191 						  & SCU_PCLK_DIV_MASK)
192 						 >> SCU_PCLK_DIV_SHIFT);
193 			rate = aspeed_get_hpll_rate(priv);
194 			rate = rate / apb_div;
195 		}
196 		break;
197 	case PCLK_UART1:
198 		rate = aspeed_get_uart_clk_rate(priv, 1);
199 		break;
200 	case PCLK_UART2:
201 		rate = aspeed_get_uart_clk_rate(priv, 2);
202 		break;
203 	case PCLK_UART3:
204 		rate = aspeed_get_uart_clk_rate(priv, 3);
205 		break;
206 	case PCLK_UART4:
207 		rate = aspeed_get_uart_clk_rate(priv, 4);
208 		break;
209 	case PCLK_UART5:
210 		rate = aspeed_get_uart_clk_rate(priv, 5);
211 		break;
212 	default:
213 		return -ENOENT;
214 	}
215 
216 	return rate;
217 }
218 
219 struct aspeed_clock_config {
220 	ulong input_rate;
221 	ulong rate;
222 	struct aspeed_div_config cfg;
223 };
224 
225 static const struct aspeed_clock_config aspeed_clock_config_defaults[] = {
226 	{ 24000000, 250000000, { .num = 124, .denum = 1, .post_div = 5 } },
227 };
228 
229 static bool aspeed_get_clock_config_default(ulong input_rate,
230 					     ulong requested_rate,
231 					     struct aspeed_div_config *cfg)
232 {
233 	int i;
234 
235 	for (i = 0; i < ARRAY_SIZE(aspeed_clock_config_defaults); i++) {
236 		const struct aspeed_clock_config *default_cfg =
237 			&aspeed_clock_config_defaults[i];
238 		if (default_cfg->input_rate == input_rate &&
239 		    default_cfg->rate == requested_rate) {
240 			*cfg = default_cfg->cfg;
241 			return true;
242 		}
243 	}
244 
245 	return false;
246 }
247 
248 /*
249  * @input_rate - the rate of input clock in Hz
250  * @requested_rate - desired output rate in Hz
251  * @div - this is an IN/OUT parameter, at input all fields of the config
252  * need to be set to their maximum allowed values.
253  * The result (the best config we could find), would also be returned
254  * in this structure.
255  *
256  * @return The clock rate, when the resulting div_config is used.
257  */
258 static ulong aspeed_calc_clock_config(ulong input_rate, ulong requested_rate,
259 				       struct aspeed_div_config *cfg)
260 {
261 	/*
262 	 * The assumption is that kHz precision is good enough and
263 	 * also enough to avoid overflow when multiplying.
264 	 */
265 	const ulong input_rate_khz = input_rate / 1000;
266 	const ulong rate_khz = requested_rate / 1000;
267 	const struct aspeed_div_config max_vals = *cfg;
268 	struct aspeed_div_config it = { 0, 0, 0 };
269 	ulong delta = rate_khz;
270 	ulong new_rate_khz = 0;
271 
272 	/*
273 	 * Look for a well known frequency first.
274 	 */
275 	if (aspeed_get_clock_config_default(input_rate, requested_rate, cfg))
276 		return requested_rate;
277 
278 	for (; it.denum <= max_vals.denum; ++it.denum) {
279 		for (it.post_div = 0; it.post_div <= max_vals.post_div;
280 		     ++it.post_div) {
281 			it.num = (rate_khz * (it.post_div + 1) / input_rate_khz)
282 			    * (it.denum + 1);
283 			if (it.num > max_vals.num)
284 				continue;
285 
286 			new_rate_khz = (input_rate_khz
287 					* ((it.num + 1) / (it.denum + 1)))
288 			    / (it.post_div + 1);
289 
290 			/* Keep the rate below requested one. */
291 			if (new_rate_khz > rate_khz)
292 				continue;
293 
294 			if (new_rate_khz - rate_khz < delta) {
295 				delta = new_rate_khz - rate_khz;
296 				*cfg = it;
297 				if (delta == 0)
298 					return new_rate_khz * 1000;
299 			}
300 		}
301 	}
302 
303 	return new_rate_khz * 1000;
304 }
305 
306 static u32 aspeed_configure_ddr(struct aspeed_clk_priv *priv, ulong rate)
307 {
308 	u32 clkin = aspeed_get_clkin(priv);
309 	u32 mpll_reg;
310 	struct aspeed_div_config div_cfg = {
311 		.num = (SCU_MPLL_NUM_MASK >> SCU_MPLL_NUM_SHIFT),
312 		.denum = (SCU_MPLL_DENUM_MASK >> SCU_MPLL_DENUM_SHIFT),
313 		.post_div = (SCU_MPLL_POST_MASK >> SCU_MPLL_POST_SHIFT),
314 	};
315 
316 	aspeed_calc_clock_config(clkin, rate, &div_cfg);
317 
318 	mpll_reg = readl(priv->regs + ASPEED_MPLL_PARAMETER);
319 	mpll_reg &= ~(SCU_MPLL_POST_MASK | SCU_MPLL_NUM_MASK
320 		      | SCU_MPLL_DENUM_MASK);
321 	mpll_reg |= (div_cfg.post_div << SCU_MPLL_POST_SHIFT)
322 	    | (div_cfg.num << SCU_MPLL_NUM_SHIFT)
323 	    | (div_cfg.denum << SCU_MPLL_DENUM_SHIFT);
324 
325 	writel(mpll_reg, priv->regs + ASPEED_MPLL_PARAMETER);
326 
327 	return aspeed_get_mpll_rate(priv);
328 }
329 
330 static u32 aspeed_configure_mac(struct aspeed_clk_priv *priv, int index)
331 {
332 	u32 clkin = aspeed_get_clkin(priv);
333 	u32 hpll_rate = aspeed_get_hpll_rate(priv);
334 	ulong required_rate;
335 	u32 hwstrap;
336 	u32 divisor;
337 	u32 reset_bit;
338 	u32 clkstop_bit;
339 #if 0
340 	/*
341 	 * According to data sheet, for 10/100 mode the MAC clock frequency
342 	 * should be at least 25MHz and for 1000 mode at least 100MHz
343 	 */
344 	hwstrap = readl(priv->regs + ASPEED_STRAP);
345 	if (hwstrap & (SCU_HWSTRAP_MAC1_RGMII | SCU_HWSTRAP_MAC2_RGMII))
346 		required_rate = 100 * 1000 * 1000;
347 	else
348 		required_rate = 25 * 1000 * 1000;
349 
350 	divisor = hpll_rate / required_rate;
351 
352 	if (divisor < 4) {
353 		/* Clock can't run fast enough, but let's try anyway */
354 		debug("MAC clock too slow\n");
355 		divisor = 4;
356 	} else if (divisor > 16) {
357 		/* Can't slow down the clock enough, but let's try anyway */
358 		debug("MAC clock too fast\n");
359 		divisor = 16;
360 	}
361 
362 	switch (index) {
363 	case 1:
364 		reset_bit = SCU_SYSRESET_MAC1;
365 		clkstop_bit = SCU_CLKSTOP_MAC1;
366 		break;
367 	case 2:
368 		reset_bit = SCU_SYSRESET_MAC2;
369 		clkstop_bit = SCU_CLKSTOP_MAC2;
370 		break;
371 	default:
372 		return -EINVAL;
373 	}
374 
375 	clrsetbits_le32(priv->regs + ASPEED_CLK_SELECT, SCU_MACCLK_MASK,
376 			((divisor - 2) / 2) << SCU_MACCLK_SHIFT);
377 
378 	/*
379 	 * Disable MAC, start its clock and re-enable it.
380 	 * The procedure and the delays (100us & 10ms) are
381 	 * specified in the datasheet.
382 	 */
383 	setbits_le32(&scu->sysreset_ctrl1, reset_bit);
384 	udelay(100);
385 	clrbits_le32(&scu->clk_stop_ctrl1, clkstop_bit);
386 	mdelay(10);
387 	clrbits_le32(&scu->sysreset_ctrl1, reset_bit);
388 
389 	writel((RGMII2_TXCK_DUTY << SCU_CLKDUTY_RGMII2TXCK_SHIFT)
390 	       | (RGMII1_TXCK_DUTY << SCU_CLKDUTY_RGMII1TXCK_SHIFT),
391 	       &scu->clk_duty_sel);
392 #endif
393 	return required_rate;
394 }
395 
396 static ulong aspeed_configure_d2pll(struct aspeed_clk_priv *priv, ulong rate)
397 {
398 	/*
399 	 * The values and the meaning of the next three
400 	 * parameters are undocumented. Taken from Aspeed SDK.
401 	 *
402 	 * TODO(clg@kaod.org): the SIP and SIC values depend on the
403 	 * Numerator value
404 	 */
405 
406 	const u32 d2_pll_ext_param = 0x2c;
407 	const u32 d2_pll_sip = 0x11;
408 	const u32 d2_pll_sic = 0x18;
409 	u32 clk_delay_settings =
410 	    (RMII_RXCLK_IDLY << SCU_MICDS_MAC1RMII_RDLY_SHIFT)
411 	    | (RMII_RXCLK_IDLY << SCU_MICDS_MAC2RMII_RDLY_SHIFT)
412 	    | (RGMII_TXCLK_ODLY << SCU_MICDS_MAC1RGMII_TXDLY_SHIFT)
413 	    | (RGMII_TXCLK_ODLY << SCU_MICDS_MAC2RGMII_TXDLY_SHIFT);
414 	struct aspeed_div_config div_cfg = {
415 		.num = SCU_D2PLL_NUM_MASK >> SCU_D2PLL_NUM_SHIFT,
416 		.denum = SCU_D2PLL_DENUM_MASK >> SCU_D2PLL_DENUM_SHIFT,
417 		.post_div = SCU_D2PLL_POST_MASK >> SCU_D2PLL_POST_SHIFT,
418 	};
419 	ulong clkin = aspeed_get_clkin(priv);
420 	ulong new_rate;
421 #if 0
422 	writel((d2_pll_ext_param << SCU_D2PLL_EXT1_PARAM_SHIFT)
423 	       | SCU_D2PLL_EXT1_OFF
424 	       | SCU_D2PLL_EXT1_RESET, &scu->d2_pll_ext_param[0]);
425 
426 	/*
427 	 * Select USB2.0 port1 PHY clock as a clock source for GCRT.
428 	 * This would disconnect it from D2-PLL.
429 	 */
430 	clrsetbits_le32(&scu->misc_ctrl1, SCU_MISC_D2PLL_OFF,
431 			SCU_MISC_GCRT_USB20CLK);
432 
433 	new_rate = aspeed_calc_clock_config(clkin, rate, &div_cfg);
434 	writel((d2_pll_sip << SCU_D2PLL_SIP_SHIFT)
435 	       | (d2_pll_sic << SCU_D2PLL_SIC_SHIFT)
436 	       | (div_cfg.num << SCU_D2PLL_NUM_SHIFT)
437 	       | (div_cfg.denum << SCU_D2PLL_DENUM_SHIFT)
438 	       | (div_cfg.post_div << SCU_D2PLL_POST_SHIFT),
439 	       &scu->d2_pll_param);
440 
441 	clrbits_le32(&scu->d2_pll_ext_param[0],
442 		     SCU_D2PLL_EXT1_OFF | SCU_D2PLL_EXT1_RESET);
443 
444 	clrsetbits_le32(&scu->misc_ctrl2,
445 			SCU_MISC2_RGMII_HPLL | SCU_MISC2_RMII_MPLL
446 			| SCU_MISC2_RGMII_CLKDIV_MASK |
447 			SCU_MISC2_RMII_CLKDIV_MASK,
448 			(4 << SCU_MISC2_RMII_CLKDIV_SHIFT));
449 
450 	writel(clk_delay_settings | SCU_MICDS_RGMIIPLL, &scu->mac_clk_delay);
451 	writel(clk_delay_settings, &scu->mac_clk_delay_100M);
452 	writel(clk_delay_settings, &scu->mac_clk_delay_10M);
453 #endif
454 	return new_rate;
455 }
456 
457 static ulong aspeed_clk_set_rate(struct clk *clk, ulong rate)
458 {
459 	struct aspeed_clk_priv *priv = dev_get_priv(clk->dev);
460 
461 	ulong new_rate;
462 	switch (clk->id) {
463 	case PLL_MPLL:
464 	case MCLK_DDR:
465 		new_rate = aspeed_configure_ddr(priv, rate);
466 		break;
467 	case PLL_D2PLL:
468 		new_rate = aspeed_configure_d2pll(priv, rate);
469 		break;
470 	default:
471 		return -ENOENT;
472 	}
473 
474 	return new_rate;
475 }
476 
477 static int aspeed_clk_enable(struct clk *clk)
478 {
479 	struct aspeed_clk_priv *priv = dev_get_priv(clk->dev);
480 
481 	switch (clk->id) {
482 	/*
483 	 * For MAC clocks the clock rate is
484 	 * configured based on whether RGMII or RMII mode has been selected
485 	 * through hardware strapping.
486 	 */
487 	case PCLK_MAC1:
488 		aspeed_configure_mac(priv, 1);
489 		break;
490 	case PCLK_MAC2:
491 		aspeed_configure_mac(priv, 2);
492 		break;
493 	case PLL_D2PLL:
494 		aspeed_configure_d2pll(priv, D2PLL_DEFAULT_RATE);
495 		break;
496 	default:
497 		return -ENOENT;
498 	}
499 
500 	return 0;
501 }
502 
503 struct clk_ops aspeed_clk_ops = {
504 	.get_rate = aspeed_clk_get_rate,
505 	.set_rate = aspeed_clk_set_rate,
506 	.enable = aspeed_clk_enable,
507 };
508 
509 static int aspeed_clk_probe(struct udevice *dev)
510 {
511 	struct aspeed_clk_priv *priv = dev_get_priv(dev);
512 
513 	priv->regs = devfdt_get_addr_ptr(dev);
514 
515 	if (IS_ERR(priv->regs))
516 		return PTR_ERR(priv->regs);
517 
518 	priv->version = dev_get_driver_data(dev);
519 
520 	return 0;
521 }
522 
523 static int aspeed_clk_bind(struct udevice *dev)
524 {
525 	int ret;
526 
527 	/* The reset driver does not have a device node, so bind it here */
528 	ret = device_bind_driver(gd->dm_root, "ast_sysreset", "reset", &dev);
529 	if (ret)
530 		debug("Warning: No reset driver: ret=%d\n", ret);
531 
532 	return 0;
533 }
534 
535 static const struct udevice_id aspeed_clk_ids[] = {
536 	{ .compatible = "aspeed,ast2500-scu", .data = AST2500},
537 	{ .compatible = "aspeed,ast2600-scu", .data = AST2600},
538 	{ }
539 };
540 
541 U_BOOT_DRIVER(aspeed_scu) = {
542 	.name		= "aspeed_scu",
543 	.id		= UCLASS_CLK,
544 	.of_match	= aspeed_clk_ids,
545 	.priv_auto_alloc_size = sizeof(struct aspeed_clk_priv),
546 	.ops		= &aspeed_clk_ops,
547 	.bind		= aspeed_clk_bind,
548 	.probe		= aspeed_clk_probe,
549 };
550