xref: /openbmc/u-boot/drivers/clk/clk_stm32f.c (revision cd1cc31f)
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 	STMMAC_CLOCK_CFG,
94 };
95 
96 struct stm32_clk_info stm32f4_clk_info = {
97 	/* 180 MHz */
98 	.sys_pll_psc = {
99 		.pll_m = 8,
100 		.pll_n = 360,
101 		.pll_p = 2,
102 		.pll_q = 8,
103 		.ahb_psc = AHB_PSC_1,
104 		.apb1_psc = APB_PSC_4,
105 		.apb2_psc = APB_PSC_2,
106 	},
107 	.has_overdrive = false,
108 	.v2 = false,
109 };
110 
111 struct stm32_clk_info stm32f7_clk_info = {
112 	/* 200 MHz */
113 	.sys_pll_psc = {
114 		.pll_m = 25,
115 		.pll_n = 400,
116 		.pll_p = 2,
117 		.pll_q = 8,
118 		.ahb_psc = AHB_PSC_1,
119 		.apb1_psc = APB_PSC_4,
120 		.apb2_psc = APB_PSC_2,
121 	},
122 	.has_overdrive = true,
123 	.v2 = true,
124 };
125 
126 struct stm32_clk {
127 	struct stm32_rcc_regs *base;
128 	struct stm32_pwr_regs *pwr_regs;
129 	struct stm32_clk_info *info;
130 };
131 
132 static int configure_clocks(struct udevice *dev)
133 {
134 	struct stm32_clk *priv = dev_get_priv(dev);
135 	struct stm32_rcc_regs *regs = priv->base;
136 	struct stm32_pwr_regs *pwr = priv->pwr_regs;
137 	struct pll_psc sys_pll_psc = priv->info->sys_pll_psc;
138 	u32 pllsaicfgr = 0;
139 
140 	/* Reset RCC configuration */
141 	setbits_le32(&regs->cr, RCC_CR_HSION);
142 	writel(0, &regs->cfgr); /* Reset CFGR */
143 	clrbits_le32(&regs->cr, (RCC_CR_HSEON | RCC_CR_CSSON
144 		| RCC_CR_PLLON | RCC_CR_PLLSAION));
145 	writel(0x24003010, &regs->pllcfgr); /* Reset value from RM */
146 	clrbits_le32(&regs->cr, RCC_CR_HSEBYP);
147 	writel(0, &regs->cir); /* Disable all interrupts */
148 
149 	/* Configure for HSE+PLL operation */
150 	setbits_le32(&regs->cr, RCC_CR_HSEON);
151 	while (!(readl(&regs->cr) & RCC_CR_HSERDY))
152 		;
153 
154 	setbits_le32(&regs->cfgr, ((
155 		sys_pll_psc.ahb_psc << RCC_CFGR_HPRE_SHIFT)
156 		| (sys_pll_psc.apb1_psc << RCC_CFGR_PPRE1_SHIFT)
157 		| (sys_pll_psc.apb2_psc << RCC_CFGR_PPRE2_SHIFT)));
158 
159 	/* Configure the main PLL */
160 	setbits_le32(&regs->pllcfgr, RCC_PLLCFGR_PLLSRC); /* pll source HSE */
161 	clrsetbits_le32(&regs->pllcfgr, RCC_PLLCFGR_PLLM_MASK,
162 			sys_pll_psc.pll_m << RCC_PLLCFGR_PLLM_SHIFT);
163 	clrsetbits_le32(&regs->pllcfgr, RCC_PLLCFGR_PLLN_MASK,
164 			sys_pll_psc.pll_n << RCC_PLLCFGR_PLLN_SHIFT);
165 	clrsetbits_le32(&regs->pllcfgr, RCC_PLLCFGR_PLLP_MASK,
166 			((sys_pll_psc.pll_p >> 1) - 1) << RCC_PLLCFGR_PLLP_SHIFT);
167 	clrsetbits_le32(&regs->pllcfgr, RCC_PLLCFGR_PLLQ_MASK,
168 			sys_pll_psc.pll_q << RCC_PLLCFGR_PLLQ_SHIFT);
169 
170 	/* Configure the SAI PLL to get a 48 MHz source */
171 	pllsaicfgr = RCC_PLLSAICFGR_PLLSAIR_2 | RCC_PLLSAICFGR_PLLSAIQ_4 |
172 		     RCC_PLLSAICFGR_PLLSAIP_4;
173 	pllsaicfgr |= 192 << RCC_PLLSAICFGR_PLLSAIN_SHIFT;
174 	writel(pllsaicfgr, &regs->pllsaicfgr);
175 
176 	/* Enable the main PLL */
177 	setbits_le32(&regs->cr, RCC_CR_PLLON);
178 	while (!(readl(&regs->cr) & RCC_CR_PLLRDY))
179 		;
180 
181 	if (priv->info->v2) { /*stm32f7 case */
182 		/* select PLLSAI as 48MHz clock source */
183 		setbits_le32(&regs->dckcfgr2, RCC_DCKCFGRX_CK48MSEL);
184 
185 		/* select 48MHz as SDMMC1 clock source */
186 		clrbits_le32(&regs->dckcfgr2, RCC_DCKCFGRX_SDMMC1SEL);
187 
188 		/* select 48MHz as SDMMC2 clock source */
189 		clrbits_le32(&regs->dckcfgr2, RCC_DCKCFGR2_SDMMC2SEL);
190 	} else  { /* stm32f4 case */
191 		/* select PLLSAI as 48MHz clock source */
192 		setbits_le32(&regs->dckcfgr, RCC_DCKCFGRX_CK48MSEL);
193 
194 		/* select 48MHz as SDMMC1 clock source */
195 		clrbits_le32(&regs->dckcfgr, RCC_DCKCFGRX_SDMMC1SEL);
196 	}
197 
198 	/* Enable the SAI PLL */
199 	setbits_le32(&regs->cr, RCC_CR_PLLSAION);
200 	while (!(readl(&regs->cr) & RCC_CR_PLLSAIRDY))
201 		;
202 
203 	setbits_le32(&regs->apb1enr, RCC_APB1ENR_PWREN);
204 
205 	if (priv->info->has_overdrive) {
206 		/*
207 		 * Enable high performance mode
208 		 * System frequency up to 200 MHz
209 		 */
210 		setbits_le32(&pwr->cr1, PWR_CR1_ODEN);
211 		/* Infinite wait! */
212 		while (!(readl(&pwr->csr1) & PWR_CSR1_ODRDY))
213 			;
214 		/* Enable the Over-drive switch */
215 		setbits_le32(&pwr->cr1, PWR_CR1_ODSWEN);
216 		/* Infinite wait! */
217 		while (!(readl(&pwr->csr1) & PWR_CSR1_ODSWRDY))
218 			;
219 	}
220 
221 	stm32_flash_latency_cfg(5);
222 	clrbits_le32(&regs->cfgr, (RCC_CFGR_SW0 | RCC_CFGR_SW1));
223 	setbits_le32(&regs->cfgr, RCC_CFGR_SW_PLL);
224 
225 	while ((readl(&regs->cfgr) & RCC_CFGR_SWS_MASK) !=
226 			RCC_CFGR_SWS_PLL)
227 		;
228 	/* gate the SAI clock, needed for MMC 1&2 clocks */
229 	setbits_le32(&regs->apb2enr, RCC_APB2ENR_SAI1EN);
230 
231 	return 0;
232 }
233 
234 static unsigned long stm32_clk_pll48clk_rate(struct stm32_clk *priv,
235 					     u32 sysclk)
236 {
237 	struct stm32_rcc_regs *regs = priv->base;
238 	u16 pllq, pllm, pllsain, pllsaip;
239 	bool pllsai;
240 
241 	pllq = (readl(&regs->pllcfgr) & RCC_PLLCFGR_PLLQ_MASK)
242 	       >> RCC_PLLCFGR_PLLQ_SHIFT;
243 
244 	if (priv->info->v2) /*stm32f7 case */
245 		pllsai = readl(&regs->dckcfgr2) & RCC_DCKCFGRX_CK48MSEL;
246 	else
247 		pllsai = readl(&regs->dckcfgr) & RCC_DCKCFGRX_CK48MSEL;
248 
249 	if (pllsai) {
250 		/* PLL48CLK is selected from PLLSAI, get PLLSAI value */
251 		pllm = (readl(&regs->pllcfgr) & RCC_PLLCFGR_PLLM_MASK);
252 		pllsain = ((readl(&regs->pllsaicfgr) & RCC_PLLCFGR_PLLSAIN_MASK)
253 			>> RCC_PLLSAICFGR_PLLSAIN_SHIFT);
254 		pllsaip = ((((readl(&regs->pllsaicfgr) & RCC_PLLCFGR_PLLSAIP_MASK)
255 			>> RCC_PLLSAICFGR_PLLSAIP_SHIFT) + 1) << 1);
256 		return ((CONFIG_STM32_HSE_HZ / pllm) * pllsain) / pllsaip;
257 	}
258 	/* PLL48CLK is selected from PLLQ */
259 	return sysclk / pllq;
260 }
261 
262 static unsigned long stm32_clk_get_rate(struct clk *clk)
263 {
264 	struct stm32_clk *priv = dev_get_priv(clk->dev);
265 	struct stm32_rcc_regs *regs = priv->base;
266 	u32 sysclk = 0;
267 	u32 shift = 0;
268 	u16 pllm, plln, pllp;
269 	/* Prescaler table lookups for clock computation */
270 	u8 ahb_psc_table[16] = {
271 		0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9
272 	};
273 	u8 apb_psc_table[8] = {
274 		0, 0, 0, 0, 1, 2, 3, 4
275 	};
276 
277 	if ((readl(&regs->cfgr) & RCC_CFGR_SWS_MASK) ==
278 			RCC_CFGR_SWS_PLL) {
279 		pllm = (readl(&regs->pllcfgr) & RCC_PLLCFGR_PLLM_MASK);
280 		plln = ((readl(&regs->pllcfgr) & RCC_PLLCFGR_PLLN_MASK)
281 			>> RCC_PLLCFGR_PLLN_SHIFT);
282 		pllp = ((((readl(&regs->pllcfgr) & RCC_PLLCFGR_PLLP_MASK)
283 			>> RCC_PLLCFGR_PLLP_SHIFT) + 1) << 1);
284 		sysclk = ((CONFIG_STM32_HSE_HZ / pllm) * plln) / pllp;
285 	} else {
286 		return -EINVAL;
287 	}
288 
289 	switch (clk->id) {
290 	/*
291 	 * AHB CLOCK: 3 x 32 bits consecutive registers are used :
292 	 * AHB1, AHB2 and AHB3
293 	 */
294 	case STM32F7_AHB1_CLOCK(GPIOA) ... STM32F7_AHB3_CLOCK(QSPI):
295 		shift = ahb_psc_table[(
296 			(readl(&regs->cfgr) & RCC_CFGR_AHB_PSC_MASK)
297 			>> RCC_CFGR_HPRE_SHIFT)];
298 		return sysclk >>= shift;
299 	/* APB1 CLOCK */
300 	case STM32F7_APB1_CLOCK(TIM2) ... STM32F7_APB1_CLOCK(UART8):
301 		shift = apb_psc_table[(
302 			(readl(&regs->cfgr) & RCC_CFGR_APB1_PSC_MASK)
303 			>> RCC_CFGR_PPRE1_SHIFT)];
304 		return sysclk >>= shift;
305 	/* APB2 CLOCK */
306 	case STM32F7_APB2_CLOCK(TIM1) ... STM32F7_APB2_CLOCK(LTDC):
307 		/*
308 		 * particular case for SDMMC1 and SDMMC2 :
309 		 * 48Mhz source clock can be from main PLL or from
310 		 * SAI PLL
311 		 */
312 		switch (clk->id) {
313 		case STM32F7_APB2_CLOCK(SDMMC1):
314 			if (readl(&regs->dckcfgr2) & RCC_DCKCFGRX_SDMMC1SEL)
315 				/* System clock is selected as SDMMC1 clock */
316 				return sysclk;
317 			else
318 				return stm32_clk_pll48clk_rate(priv, sysclk);
319 			break;
320 		case STM32F7_APB2_CLOCK(SDMMC2):
321 			if (readl(&regs->dckcfgr2) & RCC_DCKCFGR2_SDMMC2SEL)
322 				/* System clock is selected as SDMMC2 clock */
323 				return sysclk;
324 			else
325 				return stm32_clk_pll48clk_rate(priv, sysclk);
326 			break;
327 		}
328 
329 		shift = apb_psc_table[(
330 			(readl(&regs->cfgr) & RCC_CFGR_APB2_PSC_MASK)
331 			>> RCC_CFGR_PPRE2_SHIFT)];
332 		return sysclk >>= shift;
333 	default:
334 		pr_err("clock index %ld out of range\n", clk->id);
335 		return -EINVAL;
336 	}
337 }
338 
339 static int stm32_clk_enable(struct clk *clk)
340 {
341 	struct stm32_clk *priv = dev_get_priv(clk->dev);
342 	struct stm32_rcc_regs *regs = priv->base;
343 	u32 offset = clk->id / 32;
344 	u32 bit_index = clk->id % 32;
345 
346 	debug("%s: clkid = %ld, offset from AHB1ENR is %d, bit_index = %d\n",
347 	      __func__, clk->id, offset, bit_index);
348 	setbits_le32(&regs->ahb1enr + offset, BIT(bit_index));
349 
350 	return 0;
351 }
352 
353 void clock_setup(int peripheral)
354 {
355 	switch (peripheral) {
356 	case SYSCFG_CLOCK_CFG:
357 		setbits_le32(&STM32_RCC->apb2enr, RCC_APB2ENR_SYSCFGEN);
358 		break;
359 	case TIMER2_CLOCK_CFG:
360 		setbits_le32(&STM32_RCC->apb1enr, RCC_APB1ENR_TIM2EN);
361 		break;
362 	case STMMAC_CLOCK_CFG:
363 		setbits_le32(&STM32_RCC->ahb1enr, RCC_AHB1ENR_ETHMAC_EN);
364 		setbits_le32(&STM32_RCC->ahb1enr, RCC_AHB1ENR_ETHMAC_RX_EN);
365 		setbits_le32(&STM32_RCC->ahb1enr, RCC_AHB1ENR_ETHMAC_TX_EN);
366 		break;
367 	default:
368 		break;
369 	}
370 }
371 
372 static int stm32_clk_probe(struct udevice *dev)
373 {
374 	struct ofnode_phandle_args args;
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 		priv->info = &stm32f4_clk_info;
391 		break;
392 	case STM32F7:
393 		priv->info = &stm32f7_clk_info;
394 		break;
395 	default:
396 		return -EINVAL;
397 	}
398 
399 	if (priv->info->has_overdrive) {
400 		err = dev_read_phandle_with_args(dev, "st,syscfg", NULL, 0, 0,
401 						 &args);
402 		if (err) {
403 			debug("%s: can't find syscon device (%d)\n", __func__,
404 			      err);
405 			return err;
406 		}
407 
408 		priv->pwr_regs = (struct stm32_pwr_regs *)ofnode_get_addr(args.node);
409 	}
410 
411 	configure_clocks(dev);
412 
413 	return 0;
414 }
415 
416 static int stm32_clk_of_xlate(struct clk *clk, struct ofnode_phandle_args *args)
417 {
418 	debug("%s(clk=%p)\n", __func__, clk);
419 
420 	if (args->args_count != 2) {
421 		debug("Invaild args_count: %d\n", args->args_count);
422 		return -EINVAL;
423 	}
424 
425 	if (args->args_count)
426 		clk->id = args->args[1];
427 	else
428 		clk->id = 0;
429 
430 	return 0;
431 }
432 
433 static struct clk_ops stm32_clk_ops = {
434 	.of_xlate	= stm32_clk_of_xlate,
435 	.enable		= stm32_clk_enable,
436 	.get_rate	= stm32_clk_get_rate,
437 };
438 
439 U_BOOT_DRIVER(stm32fx_clk) = {
440 	.name			= "stm32fx_rcc_clock",
441 	.id			= UCLASS_CLK,
442 	.ops			= &stm32_clk_ops,
443 	.probe			= stm32_clk_probe,
444 	.priv_auto_alloc_size	= sizeof(struct stm32_clk),
445 	.flags			= DM_FLAG_PRE_RELOC,
446 };
447