stm32: clk: Add 200MHz clock configuration for stm32f746 discovery board

This patch adds 200MHz clock configuration for stm32f746 discovery board.
This patch is based on STM32F4 and emcraft's[1].

[1]:  https://github.com/EmcraftSystems/u-boot

Signed-off-by: Toshifumi NISHINAGA <tnishinaga.dev@gmail.com>

6 files changed, 319 insertions, 3 deletions

diff --git a/arch/arm/include/asm/arch-stm32f7/stm32.h b/arch/arm/include/asm/arch-stm32f7/stm32.h
index 68bdab069d..de55ae5df1 100644
--- a/arch/arm/include/asm/arch-stm32f7/stm32.h
+++ b/arch/arm/include/asm/arch-stm32f7/stm32.h
@@ -64,6 +64,52 @@ enum clock {
 };
 #define STM32_BUS_MASK          0xFFFF0000
 
+struct stm32_rcc_regs {
+	u32 cr;		/* RCC clock control */
+	u32 pllcfgr;	/* RCC PLL configuration */
+	u32 cfgr;	/* RCC clock configuration */
+	u32 cir;	/* RCC clock interrupt */
+	u32 ahb1rstr;	/* RCC AHB1 peripheral reset */
+	u32 ahb2rstr;	/* RCC AHB2 peripheral reset */
+	u32 ahb3rstr;	/* RCC AHB3 peripheral reset */
+	u32 rsv0;
+	u32 apb1rstr;	/* RCC APB1 peripheral reset */
+	u32 apb2rstr;	/* RCC APB2 peripheral reset */
+	u32 rsv1[2];
+	u32 ahb1enr;	/* RCC AHB1 peripheral clock enable */
+	u32 ahb2enr;	/* RCC AHB2 peripheral clock enable */
+	u32 ahb3enr;	/* RCC AHB3 peripheral clock enable */
+	u32 rsv2;
+	u32 apb1enr;	/* RCC APB1 peripheral clock enable */
+	u32 apb2enr;	/* RCC APB2 peripheral clock enable */
+	u32 rsv3[2];
+	u32 ahb1lpenr;	/* RCC AHB1 periph clk enable in low pwr mode */
+	u32 ahb2lpenr;	/* RCC AHB2 periph clk enable in low pwr mode */
+	u32 ahb3lpenr;	/* RCC AHB3 periph clk enable in low pwr mode */
+	u32 rsv4;
+	u32 apb1lpenr;	/* RCC APB1 periph clk enable in low pwr mode */
+	u32 apb2lpenr;	/* RCC APB2 periph clk enable in low pwr mode */
+	u32 rsv5[2];
+	u32 bdcr;	/* RCC Backup domain control */
+	u32 csr;	/* RCC clock control & status */
+	u32 rsv6[2];
+	u32 sscgr;	/* RCC spread spectrum clock generation */
+	u32 plli2scfgr;	/* RCC PLLI2S configuration */
+	u32 pllsaicfgr;
+	u32 dckcfgr;
+};
+#define STM32_RCC		((struct stm32_rcc_regs *)RCC_BASE)
+
+struct stm32_pwr_regs {
+	u32 cr1;   /* power control register 1 */
+	u32 csr1;  /* power control/status register 2 */
+	u32 cr2;   /* power control register 2 */
+	u32 csr2;  /* power control/status register 2 */
+};
+#define STM32_PWR		((struct stm32_pwr_regs *)PWR_BASE)
+
 int configure_clocks(void);
+unsigned long clock_get(enum clock clck);
+void stm32_flash_latency_cfg(int latency);
 
 #endif /* _ASM_ARCH_HARDWARE_H */
diff --git a/arch/arm/mach-stm32/stm32f7/Makefile b/arch/arm/mach-stm32/stm32f7/Makefile
index 40f1ad35b7..643d4d919c 100644
--- a/arch/arm/mach-stm32/stm32f7/Makefile
+++ b/arch/arm/mach-stm32/stm32f7/Makefile
@@ -5,4 +5,4 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-obj-y += timer.o clock.o
+obj-y += timer.o clock.o soc.o
diff --git a/arch/arm/mach-stm32/stm32f7/clock.c b/arch/arm/mach-stm32/stm32f7/clock.c
index 17a715bac9..78d22d40fd 100644
--- a/arch/arm/mach-stm32/stm32f7/clock.c
+++ b/arch/arm/mach-stm32/stm32f7/clock.c
@@ -11,6 +11,234 @@
 #include <asm/arch/stm32.h>
 #include <asm/arch/stm32_periph.h>
 
+#define RCC_CR_HSION		(1 << 0)
+#define RCC_CR_HSEON		(1 << 16)
+#define RCC_CR_HSERDY		(1 << 17)
+#define RCC_CR_HSEBYP		(1 << 18)
+#define RCC_CR_CSSON		(1 << 19)
+#define RCC_CR_PLLON		(1 << 24)
+#define RCC_CR_PLLRDY		(1 << 25)
+
+#define RCC_PLLCFGR_PLLM_MASK	0x3F
+#define RCC_PLLCFGR_PLLN_MASK	0x7FC0
+#define RCC_PLLCFGR_PLLP_MASK	0x30000
+#define RCC_PLLCFGR_PLLQ_MASK	0xF000000
+#define RCC_PLLCFGR_PLLSRC	(1 << 22)
+#define RCC_PLLCFGR_PLLM_SHIFT	0
+#define RCC_PLLCFGR_PLLN_SHIFT	6
+#define RCC_PLLCFGR_PLLP_SHIFT	16
+#define RCC_PLLCFGR_PLLQ_SHIFT	24
+
+#define RCC_CFGR_AHB_PSC_MASK	0xF0
+#define RCC_CFGR_APB1_PSC_MASK	0x1C00
+#define RCC_CFGR_APB2_PSC_MASK	0xE000
+#define RCC_CFGR_SW0		(1 << 0)
+#define RCC_CFGR_SW1		(1 << 1)
+#define RCC_CFGR_SW_MASK	0x3
+#define RCC_CFGR_SW_HSI		0
+#define RCC_CFGR_SW_HSE		RCC_CFGR_SW0
+#define RCC_CFGR_SW_PLL		RCC_CFGR_SW1
+#define RCC_CFGR_SWS0		(1 << 2)
+#define RCC_CFGR_SWS1		(1 << 3)
+#define RCC_CFGR_SWS_MASK	0xC
+#define RCC_CFGR_SWS_HSI	0
+#define RCC_CFGR_SWS_HSE	RCC_CFGR_SWS0
+#define RCC_CFGR_SWS_PLL	RCC_CFGR_SWS1
+#define RCC_CFGR_HPRE_SHIFT	4
+#define RCC_CFGR_PPRE1_SHIFT	10
+#define RCC_CFGR_PPRE2_SHIFT	13
+
+#define RCC_APB1ENR_PWREN	(1 << 28)
+
+/*
+ * RCC USART specific definitions
+ */
+#define RCC_ENR_USART1EN		(1 << 4)
+#define RCC_ENR_USART2EN		(1 << 17)
+#define RCC_ENR_USART3EN		(1 << 18)
+#define RCC_ENR_USART6EN		(1 <<  5)
+
+/*
+ * Offsets of some PWR registers
+ */
+#define PWR_CR1_ODEN		(1 << 16)
+#define PWR_CR1_ODSWEN		(1 << 17)
+#define PWR_CSR1_ODRDY		(1 << 16)
+#define PWR_CSR1_ODSWRDY	(1 << 17)
+
+
+/*
+ * RCC GPIO specific definitions
+ */
+#define RCC_ENR_GPIO_A_EN	(1 << 0)
+#define RCC_ENR_GPIO_B_EN	(1 << 1)
+#define RCC_ENR_GPIO_C_EN	(1 << 2)
+#define RCC_ENR_GPIO_D_EN	(1 << 3)
+#define RCC_ENR_GPIO_E_EN	(1 << 4)
+#define RCC_ENR_GPIO_F_EN	(1 << 5)
+#define RCC_ENR_GPIO_G_EN	(1 << 6)
+#define RCC_ENR_GPIO_H_EN	(1 << 7)
+#define RCC_ENR_GPIO_I_EN	(1 << 8)
+#define RCC_ENR_GPIO_J_EN	(1 << 9)
+#define RCC_ENR_GPIO_K_EN	(1 << 10)
+
+struct pll_psc {
+	u8	pll_m;
+	u16	pll_n;
+	u8	pll_p;
+	u8	pll_q;
+	u8	ahb_psc;
+	u8	apb1_psc;
+	u8	apb2_psc;
+};
+
+#define AHB_PSC_1		0
+#define AHB_PSC_2		0x8
+#define AHB_PSC_4		0x9
+#define AHB_PSC_8		0xA
+#define AHB_PSC_16		0xB
+#define AHB_PSC_64		0xC
+#define AHB_PSC_128		0xD
+#define AHB_PSC_256		0xE
+#define AHB_PSC_512		0xF
+
+#define APB_PSC_1		0
+#define APB_PSC_2		0x4
+#define APB_PSC_4		0x5
+#define APB_PSC_8		0x6
+#define APB_PSC_16		0x7
+
+#if !defined(CONFIG_STM32_HSE_HZ)
+#error "CONFIG_STM32_HSE_HZ not defined!"
+#else
+#if (CONFIG_STM32_HSE_HZ == 25000000)
+#if (CONFIG_SYS_CLK_FREQ == 200000000)
+/* 200 MHz */
+struct pll_psc sys_pll_psc = {
+	.pll_m = 25,
+	.pll_n = 400,
+	.pll_p = 2,
+	.pll_q = 8,
+	.ahb_psc = AHB_PSC_1,
+	.apb1_psc = APB_PSC_4,
+	.apb2_psc = APB_PSC_2
+};
+#endif
+#else
+#error "No PLL/Prescaler configuration for given CONFIG_STM32_HSE_HZ exists"
+#endif
+#endif
+
+int configure_clocks(void)
+{
+	/* Reset RCC configuration */
+	setbits_le32(&STM32_RCC->cr, RCC_CR_HSION);
+	writel(0, &STM32_RCC->cfgr); /* Reset CFGR */
+	clrbits_le32(&STM32_RCC->cr, (RCC_CR_HSEON | RCC_CR_CSSON
+		| RCC_CR_PLLON));
+	writel(0x24003010, &STM32_RCC->pllcfgr); /* Reset value from RM */
+	clrbits_le32(&STM32_RCC->cr, RCC_CR_HSEBYP);
+	writel(0, &STM32_RCC->cir); /* Disable all interrupts */
+
+	/* Configure for HSE+PLL operation */
+	setbits_le32(&STM32_RCC->cr, RCC_CR_HSEON);
+	while (!(readl(&STM32_RCC->cr) & RCC_CR_HSERDY))
+		;
+
+	setbits_le32(&STM32_RCC->cfgr, ((
+		sys_pll_psc.ahb_psc << RCC_CFGR_HPRE_SHIFT)
+		| (sys_pll_psc.apb1_psc << RCC_CFGR_PPRE1_SHIFT)
+		| (sys_pll_psc.apb2_psc << RCC_CFGR_PPRE2_SHIFT)));
+
+	/* Configure the main PLL */
+	uint32_t pllcfgr = 0;
+	pllcfgr = RCC_PLLCFGR_PLLSRC; /* pll source HSE */
+	pllcfgr |= sys_pll_psc.pll_m << RCC_PLLCFGR_PLLM_SHIFT;
+	pllcfgr |= sys_pll_psc.pll_n << RCC_PLLCFGR_PLLN_SHIFT;
+	pllcfgr |= ((sys_pll_psc.pll_p >> 1) - 1) << RCC_PLLCFGR_PLLP_SHIFT;
+	pllcfgr |= sys_pll_psc.pll_q << RCC_PLLCFGR_PLLQ_SHIFT;
+	writel(pllcfgr, &STM32_RCC->pllcfgr);
+
+	/* Enable the main PLL */
+	setbits_le32(&STM32_RCC->cr, RCC_CR_PLLON);
+	while (!(readl(&STM32_RCC->cr) & RCC_CR_PLLRDY))
+		;
+
+	/* Enable high performance mode, System frequency up to 200 MHz */
+	setbits_le32(&STM32_RCC->apb1enr, RCC_APB1ENR_PWREN);
+	setbits_le32(&STM32_PWR->cr1, PWR_CR1_ODEN);
+	/* Infinite wait! */
+	while (!(readl(&STM32_PWR->csr1) & PWR_CSR1_ODRDY))
+		;
+	/* Enable the Over-drive switch */
+	setbits_le32(&STM32_PWR->cr1, PWR_CR1_ODSWEN);
+	/* Infinite wait! */
+	while (!(readl(&STM32_PWR->csr1) & PWR_CSR1_ODSWRDY))
+		;
+
+	stm32_flash_latency_cfg(5);
+	clrbits_le32(&STM32_RCC->cfgr, (RCC_CFGR_SW0 | RCC_CFGR_SW1));
+	setbits_le32(&STM32_RCC->cfgr, RCC_CFGR_SW_PLL);
+
+	while ((readl(&STM32_RCC->cfgr) & RCC_CFGR_SWS_MASK) !=
+			RCC_CFGR_SWS_PLL)
+		;
+
+	return 0;
+}
+
+unsigned long clock_get(enum clock clck)
+{
+	u32 sysclk = 0;
+	u32 shift = 0;
+	/* Prescaler table lookups for clock computation */
+	u8 ahb_psc_table[16] = {
+		0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3, 4, 6, 7, 8, 9
+	};
+	u8 apb_psc_table[8] = {
+		0, 0, 0, 0, 1, 2, 3, 4
+	};
+
+	if ((readl(&STM32_RCC->cfgr) & RCC_CFGR_SWS_MASK) ==
+			RCC_CFGR_SWS_PLL) {
+		u16 pllm, plln, pllp;
+		pllm = (readl(&STM32_RCC->pllcfgr) & RCC_PLLCFGR_PLLM_MASK);
+		plln = ((readl(&STM32_RCC->pllcfgr) & RCC_PLLCFGR_PLLN_MASK)
+			>> RCC_PLLCFGR_PLLN_SHIFT);
+		pllp = ((((readl(&STM32_RCC->pllcfgr) & RCC_PLLCFGR_PLLP_MASK)
+			>> RCC_PLLCFGR_PLLP_SHIFT) + 1) << 1);
+		sysclk = ((CONFIG_STM32_HSE_HZ / pllm) * plln) / pllp;
+	}
+
+	switch (clck) {
+	case CLOCK_CORE:
+		return sysclk;
+		break;
+	case CLOCK_AHB:
+		shift = ahb_psc_table[(
+			(readl(&STM32_RCC->cfgr) & RCC_CFGR_AHB_PSC_MASK)
+			>> RCC_CFGR_HPRE_SHIFT)];
+		return sysclk >>= shift;
+		break;
+	case CLOCK_APB1:
+		shift = apb_psc_table[(
+			(readl(&STM32_RCC->cfgr) & RCC_CFGR_APB1_PSC_MASK)
+			>> RCC_CFGR_PPRE1_SHIFT)];
+		return sysclk >>= shift;
+		break;
+	case CLOCK_APB2:
+		shift = apb_psc_table[(
+			(readl(&STM32_RCC->cfgr) & RCC_CFGR_APB2_PSC_MASK)
+			>> RCC_CFGR_PPRE2_SHIFT)];
+		return sysclk >>= shift;
+		break;
+	default:
+		return 0;
+		break;
+	}
+}
+
+
 void clock_setup(int peripheral)
 {
 	switch (peripheral) {
diff --git a/arch/arm/mach-stm32/stm32f7/soc.c b/arch/arm/mach-stm32/stm32f7/soc.c
new file mode 100644
index 0000000000..6a1e019433
--- /dev/null
+++ b/arch/arm/mach-stm32/stm32f7/soc.c
@@ -0,0 +1,27 @@
+/*
+ * (C) Copyright 2015
+ * Kamil Lulko, <kamil.lulko@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/armv7m.h>
+#include <asm/arch/stm32.h>
+
+u32 get_cpu_rev(void)
+{
+	return 0;
+}
+
+int arch_cpu_init(void)
+{
+	configure_clocks();
+
+	return 0;
+}
+
+void s_init(void)
+{
+}
diff --git a/drivers/serial/serial_stm32x7.c b/drivers/serial/serial_stm32x7.c
index cfbfab7e41..592c0bde36 100644
--- a/drivers/serial/serial_stm32x7.c
+++ b/drivers/serial/serial_stm32x7.c
@@ -9,6 +9,7 @@
 #include <dm.h>
 #include <asm/io.h>
 #include <serial.h>
+#include <asm/arch/stm32.h>
 #include <dm/platform_data/serial_stm32x7.h>
 #include "serial_stm32x7.h"
 
@@ -18,7 +19,20 @@ static int stm32_serial_setbrg(struct udevice *dev, int baudrate)
 {
 	struct stm32x7_serial_platdata *plat = dev->platdata;
 	struct stm32_usart *const usart = plat->base;
-	writel(plat->clock/baudrate, &usart->brr);
+	u32  clock, int_div, frac_div, tmp;
+
+	if (((u32)usart & STM32_BUS_MASK) == APB1_PERIPH_BASE)
+		clock = clock_get(CLOCK_APB1);
+	else if (((u32)usart & STM32_BUS_MASK) == APB2_PERIPH_BASE)
+		clock = clock_get(CLOCK_APB2);
+	else
+		return -EINVAL;
+
+	int_div = (25 * clock) / (4 * baudrate);
+	tmp = ((int_div / 100) << USART_BRR_M_SHIFT) & USART_BRR_M_MASK;
+	frac_div = int_div - (100 * (tmp >> USART_BRR_M_SHIFT));
+	tmp |= (((frac_div * 16) + 50) / 100) & USART_BRR_F_MASK;
+	writel(tmp, &usart->brr);
 
 	return 0;
 }
diff --git a/include/configs/stm32f746-disco.h b/include/configs/stm32f746-disco.h
index e544a218dd..e1140a8e5e 100644
--- a/include/configs/stm32f746-disco.h
+++ b/include/configs/stm32f746-disco.h
@@ -42,7 +42,8 @@
 #define CONFIG_STM32_FLASH
 #define CONFIG_STM32X7_SERIAL
 
-#define CONFIG_SYS_CLK_FREQ		16*1000*1000 /* 180 MHz */
+#define CONFIG_STM32_HSE_HZ		25000000
+#define CONFIG_SYS_CLK_FREQ		200000000 /* 200 MHz */
 #define CONFIG_SYS_HZ_CLOCK		1000000	/* Timer is clocked at 1MHz */
 
 #define CONFIG_CMDLINE_TAG