xref: /openbmc/u-boot/drivers/clk/clk_stm32f.c (revision 68a69ed2a41551063f012e1ef5f18f2eb4d07f34)
1 /*
2  * Copyright (C) 2017, STMicroelectronics - All Rights Reserved
3  * Author(s): Vikas Manocha, <vikas.manocha@st.com> for STMicroelectronics.
4  *
5  * SPDX-License-Identifier:	GPL-2.0+
6  */
7 
8 #include <common.h>
9 #include <clk-uclass.h>
10 #include <dm.h>
11 #include <stm32_rcc.h>
12 
13 #include <asm/io.h>
14 #include <asm/arch/stm32.h>
15 #include <asm/arch/stm32_pwr.h>
16 
17 #include <dt-bindings/mfd/stm32f7-rcc.h>
18 
19 #define RCC_CR_HSION			BIT(0)
20 #define RCC_CR_HSEON			BIT(16)
21 #define RCC_CR_HSERDY			BIT(17)
22 #define RCC_CR_HSEBYP			BIT(18)
23 #define RCC_CR_CSSON			BIT(19)
24 #define RCC_CR_PLLON			BIT(24)
25 #define RCC_CR_PLLRDY			BIT(25)
26 #define RCC_CR_PLLSAION			BIT(28)
27 #define RCC_CR_PLLSAIRDY		BIT(29)
28 
29 #define RCC_PLLCFGR_PLLM_MASK		GENMASK(5, 0)
30 #define RCC_PLLCFGR_PLLN_MASK		GENMASK(14, 6)
31 #define RCC_PLLCFGR_PLLP_MASK		GENMASK(17, 16)
32 #define RCC_PLLCFGR_PLLQ_MASK		GENMASK(27, 24)
33 #define RCC_PLLCFGR_PLLSRC		BIT(22)
34 #define RCC_PLLCFGR_PLLM_SHIFT		0
35 #define RCC_PLLCFGR_PLLN_SHIFT		6
36 #define RCC_PLLCFGR_PLLP_SHIFT		16
37 #define RCC_PLLCFGR_PLLQ_SHIFT		24
38 
39 #define RCC_CFGR_AHB_PSC_MASK		GENMASK(7, 4)
40 #define RCC_CFGR_APB1_PSC_MASK		GENMASK(12, 10)
41 #define RCC_CFGR_APB2_PSC_MASK		GENMASK(15, 13)
42 #define RCC_CFGR_SW0			BIT(0)
43 #define RCC_CFGR_SW1			BIT(1)
44 #define RCC_CFGR_SW_MASK		GENMASK(1, 0)
45 #define RCC_CFGR_SW_HSI			0
46 #define RCC_CFGR_SW_HSE			RCC_CFGR_SW0
47 #define RCC_CFGR_SW_PLL			RCC_CFGR_SW1
48 #define RCC_CFGR_SWS0			BIT(2)
49 #define RCC_CFGR_SWS1			BIT(3)
50 #define RCC_CFGR_SWS_MASK		GENMASK(3, 2)
51 #define RCC_CFGR_SWS_HSI		0
52 #define RCC_CFGR_SWS_HSE		RCC_CFGR_SWS0
53 #define RCC_CFGR_SWS_PLL		RCC_CFGR_SWS1
54 #define RCC_CFGR_HPRE_SHIFT		4
55 #define RCC_CFGR_PPRE1_SHIFT		10
56 #define RCC_CFGR_PPRE2_SHIFT		13
57 
58 #define RCC_PLLCFGR_PLLSAIN_MASK	GENMASK(14, 6)
59 #define RCC_PLLCFGR_PLLSAIP_MASK	GENMASK(17, 16)
60 #define RCC_PLLSAICFGR_PLLSAIN_SHIFT	6
61 #define RCC_PLLSAICFGR_PLLSAIP_SHIFT	16
62 #define RCC_PLLSAICFGR_PLLSAIP_4	BIT(17)
63 #define RCC_PLLSAICFGR_PLLSAIQ_4	BIT(26)
64 #define RCC_PLLSAICFGR_PLLSAIR_2	BIT(29)
65 
66 #define RCC_DCKCFGRX_CK48MSEL		BIT(27)
67 #define RCC_DCKCFGRX_SDMMC1SEL		BIT(28)
68 #define RCC_DCKCFGR2_SDMMC2SEL		BIT(29)
69 
70 #define RCC_APB2ENR_SAI1EN		BIT(22)
71 
72 /*
73  * RCC AHB1ENR specific definitions
74  */
75 #define RCC_AHB1ENR_ETHMAC_EN		BIT(25)
76 #define RCC_AHB1ENR_ETHMAC_TX_EN	BIT(26)
77 #define RCC_AHB1ENR_ETHMAC_RX_EN	BIT(27)
78 
79 /*
80  * RCC APB1ENR specific definitions
81  */
82 #define RCC_APB1ENR_TIM2EN		BIT(0)
83 #define RCC_APB1ENR_PWREN		BIT(28)
84 
85 /*
86  * RCC APB2ENR specific definitions
87  */
88 #define RCC_APB2ENR_SYSCFGEN		BIT(14)
89 
90 enum periph_clock {
91 	SYSCFG_CLOCK_CFG,
92 	TIMER2_CLOCK_CFG,
93 };
94 
95 static const struct stm32_clk_info stm32f4_clk_info = {
96 	/* 180 MHz */
97 	.sys_pll_psc = {
98 		.pll_n = 360,
99 		.pll_p = 2,
100 		.pll_q = 8,
101 		.ahb_psc = AHB_PSC_1,
102 		.apb1_psc = APB_PSC_4,
103 		.apb2_psc = APB_PSC_2,
104 	},
105 	.has_overdrive = false,
106 	.v2 = false,
107 };
108 
109 static const struct stm32_clk_info stm32f7_clk_info = {
110 	/* 200 MHz */
111 	.sys_pll_psc = {
112 		.pll_n = 400,
113 		.pll_p = 2,
114 		.pll_q = 8,
115 		.ahb_psc = AHB_PSC_1,
116 		.apb1_psc = APB_PSC_4,
117 		.apb2_psc = APB_PSC_2,
118 	},
119 	.has_overdrive = true,
120 	.v2 = true,
121 };
122 
123 struct stm32_clk {
124 	struct stm32_rcc_regs *base;
125 	struct stm32_pwr_regs *pwr_regs;
126 	struct stm32_clk_info info;
127 	unsigned long hse_rate;
128 };
129 
130 static int configure_clocks(struct udevice *dev)
131 {
132 	struct stm32_clk *priv = dev_get_priv(dev);
133 	struct stm32_rcc_regs *regs = priv->base;
134 	struct stm32_pwr_regs *pwr = priv->pwr_regs;
135 	struct pll_psc *sys_pll_psc = &priv->info.sys_pll_psc;
136 	u32 pllsaicfgr = 0;
137 
138 	/* Reset RCC configuration */
139 	setbits_le32(&regs->cr, RCC_CR_HSION);
140 	writel(0, &regs->cfgr); /* Reset CFGR */
141 	clrbits_le32(&regs->cr, (RCC_CR_HSEON | RCC_CR_CSSON
142 		| RCC_CR_PLLON | RCC_CR_PLLSAION));
143 	writel(0x24003010, &regs->pllcfgr); /* Reset value from RM */
144 	clrbits_le32(&regs->cr, RCC_CR_HSEBYP);
145 	writel(0, &regs->cir); /* Disable all interrupts */
146 
147 	/* Configure for HSE+PLL operation */
148 	setbits_le32(&regs->cr, RCC_CR_HSEON);
149 	while (!(readl(&regs->cr) & RCC_CR_HSERDY))
150 		;
151 
152 	setbits_le32(&regs->cfgr, ((
153 		sys_pll_psc->ahb_psc << RCC_CFGR_HPRE_SHIFT)
154 		| (sys_pll_psc->apb1_psc << RCC_CFGR_PPRE1_SHIFT)
155 		| (sys_pll_psc->apb2_psc << RCC_CFGR_PPRE2_SHIFT)));
156 
157 	/* Configure the main PLL */
158 	setbits_le32(&regs->pllcfgr, RCC_PLLCFGR_PLLSRC); /* pll source HSE */
159 	clrsetbits_le32(&regs->pllcfgr, RCC_PLLCFGR_PLLM_MASK,
160 			sys_pll_psc->pll_m << RCC_PLLCFGR_PLLM_SHIFT);
161 	clrsetbits_le32(&regs->pllcfgr, RCC_PLLCFGR_PLLN_MASK,
162 			sys_pll_psc->pll_n << RCC_PLLCFGR_PLLN_SHIFT);
163 	clrsetbits_le32(&regs->pllcfgr, RCC_PLLCFGR_PLLP_MASK,
164 			((sys_pll_psc->pll_p >> 1) - 1) << RCC_PLLCFGR_PLLP_SHIFT);
165 	clrsetbits_le32(&regs->pllcfgr, RCC_PLLCFGR_PLLQ_MASK,
166 			sys_pll_psc->pll_q << RCC_PLLCFGR_PLLQ_SHIFT);
167 
168 	/* Configure the SAI PLL to get a 48 MHz source */
169 	pllsaicfgr = RCC_PLLSAICFGR_PLLSAIR_2 | RCC_PLLSAICFGR_PLLSAIQ_4 |
170 		     RCC_PLLSAICFGR_PLLSAIP_4;
171 	pllsaicfgr |= 192 << RCC_PLLSAICFGR_PLLSAIN_SHIFT;
172 	writel(pllsaicfgr, &regs->pllsaicfgr);
173 
174 	/* Enable the main PLL */
175 	setbits_le32(&regs->cr, RCC_CR_PLLON);
176 	while (!(readl(&regs->cr) & RCC_CR_PLLRDY))
177 		;
178 
179 	if (priv->info.v2) { /*stm32f7 case */
180 		/* select PLLSAI as 48MHz clock source */
181 		setbits_le32(&regs->dckcfgr2, RCC_DCKCFGRX_CK48MSEL);
182 
183 		/* select 48MHz as SDMMC1 clock source */
184 		clrbits_le32(&regs->dckcfgr2, RCC_DCKCFGRX_SDMMC1SEL);
185 
186 		/* select 48MHz as SDMMC2 clock source */
187 		clrbits_le32(&regs->dckcfgr2, RCC_DCKCFGR2_SDMMC2SEL);
188 	} else  { /* stm32f4 case */
189 		/* select PLLSAI as 48MHz clock source */
190 		setbits_le32(&regs->dckcfgr, RCC_DCKCFGRX_CK48MSEL);
191 
192 		/* select 48MHz as SDMMC1 clock source */
193 		clrbits_le32(&regs->dckcfgr, RCC_DCKCFGRX_SDMMC1SEL);
194 	}
195 
196 	/* Enable the SAI PLL */
197 	setbits_le32(&regs->cr, RCC_CR_PLLSAION);
198 	while (!(readl(&regs->cr) & RCC_CR_PLLSAIRDY))
199 		;
200 
201 	setbits_le32(&regs->apb1enr, RCC_APB1ENR_PWREN);
202 
203 	if (priv->info.has_overdrive) {
204 		/*
205 		 * Enable high performance mode
206 		 * System frequency up to 200 MHz
207 		 */
208 		setbits_le32(&pwr->cr1, PWR_CR1_ODEN);
209 		/* Infinite wait! */
210 		while (!(readl(&pwr->csr1) & PWR_CSR1_ODRDY))
211 			;
212 		/* Enable the Over-drive switch */
213 		setbits_le32(&pwr->cr1, PWR_CR1_ODSWEN);
214 		/* Infinite wait! */
215 		while (!(readl(&pwr->csr1) & PWR_CSR1_ODSWRDY))
216 			;
217 	}
218 
219 	stm32_flash_latency_cfg(5);
220 	clrbits_le32(&regs->cfgr, (RCC_CFGR_SW0 | RCC_CFGR_SW1));
221 	setbits_le32(&regs->cfgr, RCC_CFGR_SW_PLL);
222 
223 	while ((readl(&regs->cfgr) & RCC_CFGR_SWS_MASK) !=
224 			RCC_CFGR_SWS_PLL)
225 		;
226 	/* gate the SAI clock, needed for MMC 1&2 clocks */
227 	setbits_le32(&regs->apb2enr, RCC_APB2ENR_SAI1EN);
228 
229 	return 0;
230 }
231 
232 static unsigned long stm32_clk_pll48clk_rate(struct stm32_clk *priv,
233 					     u32 sysclk)
234 {
235 	struct stm32_rcc_regs *regs = priv->base;
236 	u16 pllq, pllm, pllsain, pllsaip;
237 	bool pllsai;
238 
239 	pllq = (readl(&regs->pllcfgr) & RCC_PLLCFGR_PLLQ_MASK)
240 	       >> RCC_PLLCFGR_PLLQ_SHIFT;
241 
242 	if (priv->info.v2) /*stm32f7 case */
243 		pllsai = readl(&regs->dckcfgr2) & RCC_DCKCFGRX_CK48MSEL;
244 	else
245 		pllsai = readl(&regs->dckcfgr) & RCC_DCKCFGRX_CK48MSEL;
246 
247 	if (pllsai) {
248 		/* PLL48CLK is selected from PLLSAI, get PLLSAI value */
249 		pllm = (readl(&regs->pllcfgr) & RCC_PLLCFGR_PLLM_MASK);
250 		pllsain = ((readl(&regs->pllsaicfgr) & RCC_PLLCFGR_PLLSAIN_MASK)
251 			>> RCC_PLLSAICFGR_PLLSAIN_SHIFT);
252 		pllsaip = ((((readl(&regs->pllsaicfgr) & RCC_PLLCFGR_PLLSAIP_MASK)
253 			>> RCC_PLLSAICFGR_PLLSAIP_SHIFT) + 1) << 1);
254 		return ((priv->hse_rate / pllm) * pllsain) / pllsaip;
255 	}
256 	/* PLL48CLK is selected from PLLQ */
257 	return sysclk / pllq;
258 }
259 
260 static unsigned long stm32_clk_get_rate(struct clk *clk)
261 {
262 	struct stm32_clk *priv = dev_get_priv(clk->dev);
263 	struct stm32_rcc_regs *regs = priv->base;
264 	u32 sysclk = 0;
265 	u32 shift = 0;
266 	u16 pllm, plln, pllp;
267 	/* Prescaler table lookups for clock computation */
268 	u8 ahb_psc_table[16] = {
269 		0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9
270 	};
271 	u8 apb_psc_table[8] = {
272 		0, 0, 0, 0, 1, 2, 3, 4
273 	};
274 
275 	if ((readl(&regs->cfgr) & RCC_CFGR_SWS_MASK) ==
276 			RCC_CFGR_SWS_PLL) {
277 		pllm = (readl(&regs->pllcfgr) & RCC_PLLCFGR_PLLM_MASK);
278 		plln = ((readl(&regs->pllcfgr) & RCC_PLLCFGR_PLLN_MASK)
279 			>> RCC_PLLCFGR_PLLN_SHIFT);
280 		pllp = ((((readl(&regs->pllcfgr) & RCC_PLLCFGR_PLLP_MASK)
281 			>> RCC_PLLCFGR_PLLP_SHIFT) + 1) << 1);
282 		sysclk = ((priv->hse_rate / pllm) * plln) / pllp;
283 	} else {
284 		return -EINVAL;
285 	}
286 
287 	switch (clk->id) {
288 	/*
289 	 * AHB CLOCK: 3 x 32 bits consecutive registers are used :
290 	 * AHB1, AHB2 and AHB3
291 	 */
292 	case STM32F7_AHB1_CLOCK(GPIOA) ... STM32F7_AHB3_CLOCK(QSPI):
293 		shift = ahb_psc_table[(
294 			(readl(&regs->cfgr) & RCC_CFGR_AHB_PSC_MASK)
295 			>> RCC_CFGR_HPRE_SHIFT)];
296 		return sysclk >>= shift;
297 	/* APB1 CLOCK */
298 	case STM32F7_APB1_CLOCK(TIM2) ... STM32F7_APB1_CLOCK(UART8):
299 		shift = apb_psc_table[(
300 			(readl(&regs->cfgr) & RCC_CFGR_APB1_PSC_MASK)
301 			>> RCC_CFGR_PPRE1_SHIFT)];
302 		return sysclk >>= shift;
303 	/* APB2 CLOCK */
304 	case STM32F7_APB2_CLOCK(TIM1) ... STM32F7_APB2_CLOCK(LTDC):
305 		/*
306 		 * particular case for SDMMC1 and SDMMC2 :
307 		 * 48Mhz source clock can be from main PLL or from
308 		 * SAI PLL
309 		 */
310 		switch (clk->id) {
311 		case STM32F7_APB2_CLOCK(SDMMC1):
312 			if (readl(&regs->dckcfgr2) & RCC_DCKCFGRX_SDMMC1SEL)
313 				/* System clock is selected as SDMMC1 clock */
314 				return sysclk;
315 			else
316 				return stm32_clk_pll48clk_rate(priv, sysclk);
317 			break;
318 		case STM32F7_APB2_CLOCK(SDMMC2):
319 			if (readl(&regs->dckcfgr2) & RCC_DCKCFGR2_SDMMC2SEL)
320 				/* System clock is selected as SDMMC2 clock */
321 				return sysclk;
322 			else
323 				return stm32_clk_pll48clk_rate(priv, sysclk);
324 			break;
325 		}
326 
327 		shift = apb_psc_table[(
328 			(readl(&regs->cfgr) & RCC_CFGR_APB2_PSC_MASK)
329 			>> RCC_CFGR_PPRE2_SHIFT)];
330 		return sysclk >>= shift;
331 	default:
332 		pr_err("clock index %ld out of range\n", clk->id);
333 		return -EINVAL;
334 	}
335 }
336 
337 static int stm32_clk_enable(struct clk *clk)
338 {
339 	struct stm32_clk *priv = dev_get_priv(clk->dev);
340 	struct stm32_rcc_regs *regs = priv->base;
341 	u32 offset = clk->id / 32;
342 	u32 bit_index = clk->id % 32;
343 
344 	debug("%s: clkid = %ld, offset from AHB1ENR is %d, bit_index = %d\n",
345 	      __func__, clk->id, offset, bit_index);
346 	setbits_le32(&regs->ahb1enr + offset, BIT(bit_index));
347 
348 	return 0;
349 }
350 
351 void clock_setup(int peripheral)
352 {
353 	switch (peripheral) {
354 	case SYSCFG_CLOCK_CFG:
355 		setbits_le32(&STM32_RCC->apb2enr, RCC_APB2ENR_SYSCFGEN);
356 		break;
357 	case TIMER2_CLOCK_CFG:
358 		setbits_le32(&STM32_RCC->apb1enr, RCC_APB1ENR_TIM2EN);
359 		break;
360 	default:
361 		break;
362 	}
363 }
364 
365 static int stm32_clk_probe(struct udevice *dev)
366 {
367 	struct ofnode_phandle_args args;
368 	struct udevice *fixed_clock_dev = NULL;
369 	struct clk clk;
370 	int err;
371 
372 	debug("%s\n", __func__);
373 
374 	struct stm32_clk *priv = dev_get_priv(dev);
375 	fdt_addr_t addr;
376 
377 	addr = dev_read_addr(dev);
378 	if (addr == FDT_ADDR_T_NONE)
379 		return -EINVAL;
380 
381 	priv->base = (struct stm32_rcc_regs *)addr;
382 
383 	switch (dev_get_driver_data(dev)) {
384 	case STM32F4:
385 		memcpy(&priv->info, &stm32f4_clk_info,
386 		       sizeof(struct stm32_clk_info));
387 		break;
388 	case STM32F7:
389 		memcpy(&priv->info, &stm32f7_clk_info,
390 		       sizeof(struct stm32_clk_info));
391 		break;
392 	default:
393 		return -EINVAL;
394 	}
395 
396 	/* retrieve HSE frequency (external oscillator) */
397 	err = uclass_get_device_by_name(UCLASS_CLK, "clk-hse",
398 					&fixed_clock_dev);
399 
400 	if (err) {
401 		pr_err("Can't find fixed clock (%d)", err);
402 		return err;
403 	}
404 
405 	err = clk_request(fixed_clock_dev, &clk);
406 	if (err) {
407 		pr_err("Can't request %s clk (%d)", fixed_clock_dev->name,
408 		       err);
409 		return err;
410 	}
411 
412 	/*
413 	 * set pllm factor accordingly to the external oscillator
414 	 * frequency (HSE). For STM32F4 and STM32F7, we want VCO
415 	 * freq at 1MHz
416 	 * if input PLL frequency is 25Mhz, divide it by 25
417 	 */
418 	clk.id = 0;
419 	priv->hse_rate = clk_get_rate(&clk);
420 
421 	if (priv->hse_rate < 1000000) {
422 		pr_err("%s: unexpected HSE clock rate = %ld \"n", __func__,
423 		       priv->hse_rate);
424 		return -EINVAL;
425 	}
426 
427 	priv->info.sys_pll_psc.pll_m = priv->hse_rate / 1000000;
428 
429 	if (priv->info.has_overdrive) {
430 		err = dev_read_phandle_with_args(dev, "st,syscfg", NULL, 0, 0,
431 						 &args);
432 		if (err) {
433 			debug("%s: can't find syscon device (%d)\n", __func__,
434 			      err);
435 			return err;
436 		}
437 
438 		priv->pwr_regs = (struct stm32_pwr_regs *)ofnode_get_addr(args.node);
439 	}
440 
441 	configure_clocks(dev);
442 
443 	return 0;
444 }
445 
446 static int stm32_clk_of_xlate(struct clk *clk, struct ofnode_phandle_args *args)
447 {
448 	debug("%s(clk=%p)\n", __func__, clk);
449 
450 	if (args->args_count != 2) {
451 		debug("Invaild args_count: %d\n", args->args_count);
452 		return -EINVAL;
453 	}
454 
455 	if (args->args_count)
456 		clk->id = args->args[1];
457 	else
458 		clk->id = 0;
459 
460 	return 0;
461 }
462 
463 static struct clk_ops stm32_clk_ops = {
464 	.of_xlate	= stm32_clk_of_xlate,
465 	.enable		= stm32_clk_enable,
466 	.get_rate	= stm32_clk_get_rate,
467 };
468 
469 U_BOOT_DRIVER(stm32fx_clk) = {
470 	.name			= "stm32fx_rcc_clock",
471 	.id			= UCLASS_CLK,
472 	.ops			= &stm32_clk_ops,
473 	.probe			= stm32_clk_probe,
474 	.priv_auto_alloc_size	= sizeof(struct stm32_clk),
475 	.flags			= DM_FLAG_PRE_RELOC,
476 };
477