xref: /openbmc/u-boot/drivers/clk/clk_stm32f.c (revision 8cf22313)
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(16)
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 /*
71  * RCC AHB1ENR specific definitions
72  */
73 #define RCC_AHB1ENR_ETHMAC_EN		BIT(25)
74 #define RCC_AHB1ENR_ETHMAC_TX_EN	BIT(26)
75 #define RCC_AHB1ENR_ETHMAC_RX_EN	BIT(27)
76 
77 /*
78  * RCC APB1ENR specific definitions
79  */
80 #define RCC_APB1ENR_TIM2EN		BIT(0)
81 #define RCC_APB1ENR_PWREN		BIT(28)
82 
83 /*
84  * RCC APB2ENR specific definitions
85  */
86 #define RCC_APB2ENR_SYSCFGEN		BIT(14)
87 #define RCC_APB2ENR_SAI1EN		BIT(22)
88 
89 enum periph_clock {
90 	TIMER2_CLOCK_CFG,
91 };
92 
93 static const struct stm32_clk_info stm32f4_clk_info = {
94 	/* 180 MHz */
95 	.sys_pll_psc = {
96 		.pll_n = 360,
97 		.pll_p = 2,
98 		.pll_q = 8,
99 		.ahb_psc = AHB_PSC_1,
100 		.apb1_psc = APB_PSC_4,
101 		.apb2_psc = APB_PSC_2,
102 	},
103 	.has_overdrive = false,
104 	.v2 = false,
105 };
106 
107 static const struct stm32_clk_info stm32f7_clk_info = {
108 	/* 200 MHz */
109 	.sys_pll_psc = {
110 		.pll_n = 400,
111 		.pll_p = 2,
112 		.pll_q = 8,
113 		.ahb_psc = AHB_PSC_1,
114 		.apb1_psc = APB_PSC_4,
115 		.apb2_psc = APB_PSC_2,
116 	},
117 	.has_overdrive = true,
118 	.v2 = true,
119 };
120 
121 struct stm32_clk {
122 	struct stm32_rcc_regs *base;
123 	struct stm32_pwr_regs *pwr_regs;
124 	struct stm32_clk_info info;
125 	unsigned long hse_rate;
126 };
127 
128 static int configure_clocks(struct udevice *dev)
129 {
130 	struct stm32_clk *priv = dev_get_priv(dev);
131 	struct stm32_rcc_regs *regs = priv->base;
132 	struct stm32_pwr_regs *pwr = priv->pwr_regs;
133 	struct pll_psc *sys_pll_psc = &priv->info.sys_pll_psc;
134 	u32 pllsaicfgr = 0;
135 
136 	/* Reset RCC configuration */
137 	setbits_le32(&regs->cr, RCC_CR_HSION);
138 	writel(0, &regs->cfgr); /* Reset CFGR */
139 	clrbits_le32(&regs->cr, (RCC_CR_HSEON | RCC_CR_CSSON
140 		| RCC_CR_PLLON | RCC_CR_PLLSAION));
141 	writel(0x24003010, &regs->pllcfgr); /* Reset value from RM */
142 	clrbits_le32(&regs->cr, RCC_CR_HSEBYP);
143 	writel(0, &regs->cir); /* Disable all interrupts */
144 
145 	/* Configure for HSE+PLL operation */
146 	setbits_le32(&regs->cr, RCC_CR_HSEON);
147 	while (!(readl(&regs->cr) & RCC_CR_HSERDY))
148 		;
149 
150 	setbits_le32(&regs->cfgr, ((
151 		sys_pll_psc->ahb_psc << RCC_CFGR_HPRE_SHIFT)
152 		| (sys_pll_psc->apb1_psc << RCC_CFGR_PPRE1_SHIFT)
153 		| (sys_pll_psc->apb2_psc << RCC_CFGR_PPRE2_SHIFT)));
154 
155 	/* Configure the main PLL */
156 	setbits_le32(&regs->pllcfgr, RCC_PLLCFGR_PLLSRC); /* pll source HSE */
157 	clrsetbits_le32(&regs->pllcfgr, RCC_PLLCFGR_PLLM_MASK,
158 			sys_pll_psc->pll_m << RCC_PLLCFGR_PLLM_SHIFT);
159 	clrsetbits_le32(&regs->pllcfgr, RCC_PLLCFGR_PLLN_MASK,
160 			sys_pll_psc->pll_n << RCC_PLLCFGR_PLLN_SHIFT);
161 	clrsetbits_le32(&regs->pllcfgr, RCC_PLLCFGR_PLLP_MASK,
162 			((sys_pll_psc->pll_p >> 1) - 1) << RCC_PLLCFGR_PLLP_SHIFT);
163 	clrsetbits_le32(&regs->pllcfgr, RCC_PLLCFGR_PLLQ_MASK,
164 			sys_pll_psc->pll_q << RCC_PLLCFGR_PLLQ_SHIFT);
165 
166 	/* Configure the SAI PLL to get a 48 MHz source */
167 	pllsaicfgr = RCC_PLLSAICFGR_PLLSAIR_2 | RCC_PLLSAICFGR_PLLSAIQ_4 |
168 		     RCC_PLLSAICFGR_PLLSAIP_4;
169 	pllsaicfgr |= 192 << RCC_PLLSAICFGR_PLLSAIN_SHIFT;
170 	writel(pllsaicfgr, &regs->pllsaicfgr);
171 
172 	/* Enable the main PLL */
173 	setbits_le32(&regs->cr, RCC_CR_PLLON);
174 	while (!(readl(&regs->cr) & RCC_CR_PLLRDY))
175 		;
176 
177 	if (priv->info.v2) { /*stm32f7 case */
178 		/* select PLLSAI as 48MHz clock source */
179 		setbits_le32(&regs->dckcfgr2, RCC_DCKCFGRX_CK48MSEL);
180 
181 		/* select 48MHz as SDMMC1 clock source */
182 		clrbits_le32(&regs->dckcfgr2, RCC_DCKCFGRX_SDMMC1SEL);
183 
184 		/* select 48MHz as SDMMC2 clock source */
185 		clrbits_le32(&regs->dckcfgr2, RCC_DCKCFGR2_SDMMC2SEL);
186 	} else  { /* stm32f4 case */
187 		/* select PLLSAI as 48MHz clock source */
188 		setbits_le32(&regs->dckcfgr, RCC_DCKCFGRX_CK48MSEL);
189 
190 		/* select 48MHz as SDMMC1 clock source */
191 		clrbits_le32(&regs->dckcfgr, RCC_DCKCFGRX_SDMMC1SEL);
192 	}
193 
194 	/* Enable the SAI PLL */
195 	setbits_le32(&regs->cr, RCC_CR_PLLSAION);
196 	while (!(readl(&regs->cr) & RCC_CR_PLLSAIRDY))
197 		;
198 
199 	setbits_le32(&regs->apb1enr, RCC_APB1ENR_PWREN);
200 
201 	if (priv->info.has_overdrive) {
202 		/*
203 		 * Enable high performance mode
204 		 * System frequency up to 200 MHz
205 		 */
206 		setbits_le32(&pwr->cr1, PWR_CR1_ODEN);
207 		/* Infinite wait! */
208 		while (!(readl(&pwr->csr1) & PWR_CSR1_ODRDY))
209 			;
210 		/* Enable the Over-drive switch */
211 		setbits_le32(&pwr->cr1, PWR_CR1_ODSWEN);
212 		/* Infinite wait! */
213 		while (!(readl(&pwr->csr1) & PWR_CSR1_ODSWRDY))
214 			;
215 	}
216 
217 	stm32_flash_latency_cfg(5);
218 	clrbits_le32(&regs->cfgr, (RCC_CFGR_SW0 | RCC_CFGR_SW1));
219 	setbits_le32(&regs->cfgr, RCC_CFGR_SW_PLL);
220 
221 	while ((readl(&regs->cfgr) & RCC_CFGR_SWS_MASK) !=
222 			RCC_CFGR_SWS_PLL)
223 		;
224 	/* gate the SAI clock, needed for MMC 1&2 clocks */
225 	setbits_le32(&regs->apb2enr, RCC_APB2ENR_SAI1EN);
226 
227 #ifdef CONFIG_ETH_DESIGNWARE
228 	/* gate the SYSCFG clock, needed to set RMII ethernet interface */
229 	setbits_le32(&regs->apb2enr, RCC_APB2ENR_SYSCFGEN);
230 #endif
231 
232 	return 0;
233 }
234 
235 static unsigned long stm32_clk_pll48clk_rate(struct stm32_clk *priv,
236 					     u32 sysclk)
237 {
238 	struct stm32_rcc_regs *regs = priv->base;
239 	u16 pllq, pllm, pllsain, pllsaip;
240 	bool pllsai;
241 
242 	pllq = (readl(&regs->pllcfgr) & RCC_PLLCFGR_PLLQ_MASK)
243 	       >> RCC_PLLCFGR_PLLQ_SHIFT;
244 
245 	if (priv->info.v2) /*stm32f7 case */
246 		pllsai = readl(&regs->dckcfgr2) & RCC_DCKCFGRX_CK48MSEL;
247 	else
248 		pllsai = readl(&regs->dckcfgr) & RCC_DCKCFGRX_CK48MSEL;
249 
250 	if (pllsai) {
251 		/* PLL48CLK is selected from PLLSAI, get PLLSAI value */
252 		pllm = (readl(&regs->pllcfgr) & RCC_PLLCFGR_PLLM_MASK);
253 		pllsain = ((readl(&regs->pllsaicfgr) & RCC_PLLCFGR_PLLSAIN_MASK)
254 			>> RCC_PLLSAICFGR_PLLSAIN_SHIFT);
255 		pllsaip = ((((readl(&regs->pllsaicfgr) & RCC_PLLCFGR_PLLSAIP_MASK)
256 			>> RCC_PLLSAICFGR_PLLSAIP_SHIFT) + 1) << 1);
257 		return ((priv->hse_rate / pllm) * pllsain) / pllsaip;
258 	}
259 	/* PLL48CLK is selected from PLLQ */
260 	return sysclk / pllq;
261 }
262 
263 static unsigned long stm32_clk_get_rate(struct clk *clk)
264 {
265 	struct stm32_clk *priv = dev_get_priv(clk->dev);
266 	struct stm32_rcc_regs *regs = priv->base;
267 	u32 sysclk = 0;
268 	u32 shift = 0;
269 	u16 pllm, plln, pllp;
270 	/* Prescaler table lookups for clock computation */
271 	u8 ahb_psc_table[16] = {
272 		0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9
273 	};
274 	u8 apb_psc_table[8] = {
275 		0, 0, 0, 0, 1, 2, 3, 4
276 	};
277 
278 	if ((readl(&regs->cfgr) & RCC_CFGR_SWS_MASK) ==
279 			RCC_CFGR_SWS_PLL) {
280 		pllm = (readl(&regs->pllcfgr) & RCC_PLLCFGR_PLLM_MASK);
281 		plln = ((readl(&regs->pllcfgr) & RCC_PLLCFGR_PLLN_MASK)
282 			>> RCC_PLLCFGR_PLLN_SHIFT);
283 		pllp = ((((readl(&regs->pllcfgr) & RCC_PLLCFGR_PLLP_MASK)
284 			>> RCC_PLLCFGR_PLLP_SHIFT) + 1) << 1);
285 		sysclk = ((priv->hse_rate / pllm) * plln) / pllp;
286 	} else {
287 		return -EINVAL;
288 	}
289 
290 	switch (clk->id) {
291 	/*
292 	 * AHB CLOCK: 3 x 32 bits consecutive registers are used :
293 	 * AHB1, AHB2 and AHB3
294 	 */
295 	case STM32F7_AHB1_CLOCK(GPIOA) ... STM32F7_AHB3_CLOCK(QSPI):
296 		shift = ahb_psc_table[(
297 			(readl(&regs->cfgr) & RCC_CFGR_AHB_PSC_MASK)
298 			>> RCC_CFGR_HPRE_SHIFT)];
299 		return sysclk >>= shift;
300 	/* APB1 CLOCK */
301 	case STM32F7_APB1_CLOCK(TIM2) ... STM32F7_APB1_CLOCK(UART8):
302 		shift = apb_psc_table[(
303 			(readl(&regs->cfgr) & RCC_CFGR_APB1_PSC_MASK)
304 			>> RCC_CFGR_PPRE1_SHIFT)];
305 		return sysclk >>= shift;
306 	/* APB2 CLOCK */
307 	case STM32F7_APB2_CLOCK(TIM1) ... STM32F7_APB2_CLOCK(LTDC):
308 		/*
309 		 * particular case for SDMMC1 and SDMMC2 :
310 		 * 48Mhz source clock can be from main PLL or from
311 		 * SAI PLL
312 		 */
313 		switch (clk->id) {
314 		case STM32F7_APB2_CLOCK(SDMMC1):
315 			if (readl(&regs->dckcfgr2) & RCC_DCKCFGRX_SDMMC1SEL)
316 				/* System clock is selected as SDMMC1 clock */
317 				return sysclk;
318 			else
319 				return stm32_clk_pll48clk_rate(priv, sysclk);
320 			break;
321 		case STM32F7_APB2_CLOCK(SDMMC2):
322 			if (readl(&regs->dckcfgr2) & RCC_DCKCFGR2_SDMMC2SEL)
323 				/* System clock is selected as SDMMC2 clock */
324 				return sysclk;
325 			else
326 				return stm32_clk_pll48clk_rate(priv, sysclk);
327 			break;
328 		}
329 
330 		shift = apb_psc_table[(
331 			(readl(&regs->cfgr) & RCC_CFGR_APB2_PSC_MASK)
332 			>> RCC_CFGR_PPRE2_SHIFT)];
333 		return sysclk >>= shift;
334 	default:
335 		pr_err("clock index %ld out of range\n", clk->id);
336 		return -EINVAL;
337 	}
338 }
339 
340 static ulong stm32_set_rate(struct clk *clk, ulong rate)
341 {
342 	return 0;
343 }
344 
345 static int stm32_clk_enable(struct clk *clk)
346 {
347 	struct stm32_clk *priv = dev_get_priv(clk->dev);
348 	struct stm32_rcc_regs *regs = priv->base;
349 	u32 offset = clk->id / 32;
350 	u32 bit_index = clk->id % 32;
351 
352 	debug("%s: clkid = %ld, offset from AHB1ENR is %d, bit_index = %d\n",
353 	      __func__, clk->id, offset, bit_index);
354 	setbits_le32(&regs->ahb1enr + offset, BIT(bit_index));
355 
356 	return 0;
357 }
358 
359 void clock_setup(int peripheral)
360 {
361 	switch (peripheral) {
362 	case TIMER2_CLOCK_CFG:
363 		setbits_le32(&STM32_RCC->apb1enr, RCC_APB1ENR_TIM2EN);
364 		break;
365 	default:
366 		break;
367 	}
368 }
369 
370 static int stm32_clk_probe(struct udevice *dev)
371 {
372 	struct ofnode_phandle_args args;
373 	struct udevice *fixed_clock_dev = NULL;
374 	struct clk clk;
375 	int err;
376 
377 	debug("%s\n", __func__);
378 
379 	struct stm32_clk *priv = dev_get_priv(dev);
380 	fdt_addr_t addr;
381 
382 	addr = dev_read_addr(dev);
383 	if (addr == FDT_ADDR_T_NONE)
384 		return -EINVAL;
385 
386 	priv->base = (struct stm32_rcc_regs *)addr;
387 
388 	switch (dev_get_driver_data(dev)) {
389 	case STM32F4:
390 		memcpy(&priv->info, &stm32f4_clk_info,
391 		       sizeof(struct stm32_clk_info));
392 		break;
393 	case STM32F7:
394 		memcpy(&priv->info, &stm32f7_clk_info,
395 		       sizeof(struct stm32_clk_info));
396 		break;
397 	default:
398 		return -EINVAL;
399 	}
400 
401 	/* retrieve HSE frequency (external oscillator) */
402 	err = uclass_get_device_by_name(UCLASS_CLK, "clk-hse",
403 					&fixed_clock_dev);
404 
405 	if (err) {
406 		pr_err("Can't find fixed clock (%d)", err);
407 		return err;
408 	}
409 
410 	err = clk_request(fixed_clock_dev, &clk);
411 	if (err) {
412 		pr_err("Can't request %s clk (%d)", fixed_clock_dev->name,
413 		       err);
414 		return err;
415 	}
416 
417 	/*
418 	 * set pllm factor accordingly to the external oscillator
419 	 * frequency (HSE). For STM32F4 and STM32F7, we want VCO
420 	 * freq at 1MHz
421 	 * if input PLL frequency is 25Mhz, divide it by 25
422 	 */
423 	clk.id = 0;
424 	priv->hse_rate = clk_get_rate(&clk);
425 
426 	if (priv->hse_rate < 1000000) {
427 		pr_err("%s: unexpected HSE clock rate = %ld \"n", __func__,
428 		       priv->hse_rate);
429 		return -EINVAL;
430 	}
431 
432 	priv->info.sys_pll_psc.pll_m = priv->hse_rate / 1000000;
433 
434 	if (priv->info.has_overdrive) {
435 		err = dev_read_phandle_with_args(dev, "st,syscfg", NULL, 0, 0,
436 						 &args);
437 		if (err) {
438 			debug("%s: can't find syscon device (%d)\n", __func__,
439 			      err);
440 			return err;
441 		}
442 
443 		priv->pwr_regs = (struct stm32_pwr_regs *)ofnode_get_addr(args.node);
444 	}
445 
446 	configure_clocks(dev);
447 
448 	return 0;
449 }
450 
451 static int stm32_clk_of_xlate(struct clk *clk, struct ofnode_phandle_args *args)
452 {
453 	debug("%s(clk=%p)\n", __func__, clk);
454 
455 	if (args->args_count != 2) {
456 		debug("Invaild args_count: %d\n", args->args_count);
457 		return -EINVAL;
458 	}
459 
460 	if (args->args_count)
461 		clk->id = args->args[1];
462 	else
463 		clk->id = 0;
464 
465 	return 0;
466 }
467 
468 static struct clk_ops stm32_clk_ops = {
469 	.of_xlate	= stm32_clk_of_xlate,
470 	.enable		= stm32_clk_enable,
471 	.get_rate	= stm32_clk_get_rate,
472 	.set_rate	= stm32_set_rate,
473 };
474 
475 U_BOOT_DRIVER(stm32fx_clk) = {
476 	.name			= "stm32fx_rcc_clock",
477 	.id			= UCLASS_CLK,
478 	.ops			= &stm32_clk_ops,
479 	.probe			= stm32_clk_probe,
480 	.priv_auto_alloc_size	= sizeof(struct stm32_clk),
481 	.flags			= DM_FLAG_PRE_RELOC,
482 };
483