altos: Make STM clock configuration per-product. Fix 32MHz CPU speed

This moves all of the STM clock configuration into ao_pins.h so that
each product can configure it separately. While doing this, I
discovered that the flash memory mode (64-bit, prefetch, latency 1)
wasn't actually getting set, which is why the CPU refused to work at
32MHz.

Signed-off-by: Keith Packard <keithp@keithp.com>

7 files changed, 113 insertions, 38 deletions

diff --git a/src/megametrum-v0.1/ao_pins.h b/src/megametrum-v0.1/ao_pins.h
index 803678b2..f5789cf9 100644
--- a/src/megametrum-v0.1/ao_pins.h
+++ b/src/megametrum-v0.1/ao_pins.h
@@ -18,6 +18,29 @@
 #ifndef _AO_PINS_H_
 #define _AO_PINS_H_
 
+/* 8MHz High speed external crystal */
+#define AO_HSE			8000000
+
+/* PLLVCO = 96MHz (so that USB will work*/
+#define AO_PLLMUL		12
+#define AO_RCC_CFGR_PLLMUL	(STM_RCC_CFGR_PLLMUL_12)
+
+/* SYSCLK = 32MHz (no need to go faster than CPU) */
+#define AO_PLLDIV		3
+#define AO_RCC_CFGR_PLLDIV	(STM_RCC_CFGR_PLLDIV_3)
+
+/* HCLK = 32MHz (CPU clock) */
+#define AO_AHB_PRESCALER	1
+#define AO_RCC_CFGR_HPRE_DIV	STM_RCC_CFGR_HPRE_DIV_1
+
+/* Run APB1 at 16MHz (HCLK/2) */
+#define AO_APB1_PRESCALER	2
+#define AO_RCC_CFGR_PPRE1_DIV	STM_RCC_CFGR_PPRE2_DIV_2
+
+/* Run APB2 at 16MHz (HCLK/2) */
+#define AO_APB2_PRESCALER	2
+#define AO_RCC_CFGR_PPRE2_DIV	STM_RCC_CFGR_PPRE2_DIV_2
+
 #define HAS_SERIAL_1		1
 #define USE_SERIAL_1_STDIN	1
 #define SERIAL_1_PB6_PB7	0
diff --git a/src/stm-demo/ao_pins.h b/src/stm-demo/ao_pins.h
index 9fd1175d..3192c2b7 100644
--- a/src/stm-demo/ao_pins.h
+++ b/src/stm-demo/ao_pins.h
@@ -18,6 +18,23 @@
 #ifndef _AO_PINS_H_
 #define _AO_PINS_H_
 
+/* No external crystal */
+#define AO_HSE		0
+
+#define AO_AHB_PRESCALER	1
+#define AO_RCC_CFGR_HPRE_DIV	STM_RCC_CFGR_HPRE_DIV_1
+
+#define AO_APB1_PRESCALER	2
+#define AO_RCC_CFGR_PPRE1_DIV	STM_RCC_CFGR_PPRE2_DIV_2
+
+#define AO_APB2_PRESCALER	2
+#define AO_RCC_CFGR_PPRE2_DIV	STM_RCC_CFGR_PPRE2_DIV_2
+
+#define AO_PLLMUL		6
+#define AO_PLLDIV		4
+#define AO_RCC_CFGR_PLLMUL	(STM_RCC_CFGR_PLLMUL_6)
+#define AO_RCC_CFGR_PLLDIV	(STM_RCC_CFGR_PLLDIV_4)
+
 #define HAS_SERIAL_1		1
 #define USE_SERIAL_1_STDIN	1
 #define SERIAL_1_PB6_PB7	1
diff --git a/src/stm/ao_arch.h b/src/stm/ao_arch.h
index ce3a22e2..dd9579f1 100644
--- a/src/stm/ao_arch.h
+++ b/src/stm/ao_arch.h
@@ -148,7 +148,30 @@ extern const uint16_t ao_serial_number;
 /*
  * For now, we're running at a weird frequency
  */
-#define STM_APB1	(16000000 * 6 / 4)
+
+#if AO_HSE
+#define AO_PLLSRC	AO_HSE
+#else
+#define AO_PLLSRC	STM_HSI_FREQ
+#endif
+
+#define AO_PLLVCO	(AO_PLLSRC * AO_PLLMUL)
+#define AO_SYSCLK	(AO_PLLVCO / AO_PLLDIV)
+#define AO_HCLK		(AO_SYSCLK / AO_AHB_PRESCALER)
+#define AO_PCLK1	(AO_HCLK / AO_APB1_PRESCALER)
+#define AO_PCLK2	(AO_HCLK / AO_APB2_PRESCALER)
+
+#if AO_APB1_PRESCALER == 1
+#define AO_TIM23467_CLK		AO_PCLK1
+#else
+#define AO_TIM23467_CLK		(2 * AO_PCLK1)
+#endif
+
+#if AO_APB2_PRESCALER == 1
+#define AO_TIM91011_CLK		AO_PCLK2
+#else
+#define AO_TIM91011_CLK		(2 * AO_PCLK2)
+#endif
 
 void ao_lcd_stm_init(void);
 
diff --git a/src/stm/ao_beep_stm.c b/src/stm/ao_beep_stm.c
index 8c0c0ee3..37c30e25 100644
--- a/src/stm/ao_beep_stm.c
+++ b/src/stm/ao_beep_stm.c
@@ -41,7 +41,7 @@ ao_beep(uint8_t beep)
 
 		/* Set prescaler to match cc1111 clocks
 		 */
-		stm_tim3.psc = STM_APB1 / 750000;
+		stm_tim3.psc = AO_TIM23467_CLK / 750000;
 
 		/* 1. Select the counter clock (internal, external, prescaler).
 		 *
diff --git a/src/stm/ao_serial_stm.c b/src/stm/ao_serial_stm.c
index f8db6883..3cebc094 100644
--- a/src/stm/ao_serial_stm.c
+++ b/src/stm/ao_serial_stm.c
@@ -116,16 +116,16 @@ static const struct {
 	uint32_t brr;
 } ao_usart_speeds[] = {
 	[AO_SERIAL_SPEED_4800] = {
-		STM_APB1 / 4800
+		AO_PCLK1 / 4800
 	},
 	[AO_SERIAL_SPEED_9600] = {
-		STM_APB1 / 9600
+		AO_PCLK1 / 9600
 	},
 	[AO_SERIAL_SPEED_19200] = {
-		STM_APB1 / 19200
+		AO_PCLK1 / 19200
 	},
 	[AO_SERIAL_SPEED_57600] = {
-		STM_APB1 / 57600
+		AO_PCLK1 / 57600
 	},
 };
 
diff --git a/src/stm/ao_timer.c b/src/stm/ao_timer.c
index 387df184..e7f1ddfe 100644
--- a/src/stm/ao_timer.c
+++ b/src/stm/ao_timer.c
@@ -69,7 +69,7 @@ ao_timer_set_adc_interval(uint8_t interval) __critical
 }
 #endif
 
-#define TIMER_10kHz	(STM_APB1 / 10000)
+#define TIMER_10kHz	(AO_PCLK1 / 10000)
 
 void
 ao_timer_init(void)
@@ -107,44 +107,41 @@ ao_clock_init(void)
 	uint32_t	cr;
 	
 	/* Set flash latency to tolerate 32MHz SYSCLK  -> 1 wait state */
-	uint32_t	acr = stm_flash.acr;
 
 	/* Enable 64-bit access and prefetch */
-	acr |= (1 << STM_FLASH_ACR_ACC64) | (1 << STM_FLASH_ACR_PRFEN);
-	stm_flash.acr = acr;
+	stm_flash.acr |= (1 << STM_FLASH_ACR_ACC64);
+	stm_flash.acr |= (1 << STM_FLASH_ACR_PRFEN);
 
 	/* Enable 1 wait state so the CPU can run at 32MHz */
 	/* (haven't managed to run the CPU at 32MHz yet, it's at 16MHz) */
-	acr |= (1 << STM_FLASH_ACR_LATENCY);
-	stm_flash.acr = acr;
+	stm_flash.acr |= (1 << STM_FLASH_ACR_LATENCY);
+
 
 	/* HCLK to 16MHz -> AHB prescaler = /1 */
 	cfgr = stm_rcc.cfgr;
 	cfgr &= ~(STM_RCC_CFGR_HPRE_MASK << STM_RCC_CFGR_HPRE);
-	cfgr |= (STM_RCC_CFGR_HPRE_DIV_1 << STM_RCC_CFGR_HPRE);
+	cfgr |= (AO_RCC_CFGR_HPRE_DIV << STM_RCC_CFGR_HPRE);
 	stm_rcc.cfgr = cfgr;
 	while ((stm_rcc.cfgr & (STM_RCC_CFGR_HPRE_MASK << STM_RCC_CFGR_HPRE)) !=
-	       (STM_RCC_CFGR_HPRE_DIV_1 << STM_RCC_CFGR_HPRE))
+	       (AO_RCC_CFGR_HPRE_DIV << STM_RCC_CFGR_HPRE))
 		asm ("nop");
-#define STM_AHB_PRESCALER	1
 
-	/* PCLK1 to 16MHz -> APB1 Prescaler = 1 */
+	/* APB1 Prescaler = AO_APB1_PRESCALER */
 	cfgr = stm_rcc.cfgr;
 	cfgr &= ~(STM_RCC_CFGR_PPRE1_MASK << STM_RCC_CFGR_PPRE1);
-	cfgr |= (STM_RCC_CFGR_PPRE1_DIV_1 << STM_RCC_CFGR_PPRE1);
+	cfgr |= (AO_RCC_CFGR_PPRE1_DIV << STM_RCC_CFGR_PPRE1);
 	stm_rcc.cfgr = cfgr;
-#define STM_APB1_PRESCALER	1
 
-	/* PCLK2 to 16MHz -> APB2 Prescaler = 1 */
+	/* APB2 Prescaler = AO_APB2_PRESCALER */
 	cfgr = stm_rcc.cfgr;
 	cfgr &= ~(STM_RCC_CFGR_PPRE2_MASK << STM_RCC_CFGR_PPRE2);
-	cfgr |= (STM_RCC_CFGR_PPRE2_DIV_1 << STM_RCC_CFGR_PPRE2);
+	cfgr |= (AO_RCC_CFGR_PPRE2_DIV << STM_RCC_CFGR_PPRE2);
 	stm_rcc.cfgr = cfgr;
-#define STM_APB2_PRESCALER	1
 
 	/* Enable power interface clock */
 	stm_rcc.apb1enr |= (1 << STM_RCC_APB1ENR_PWREN);
 
+
 	/* Set voltage range to 1.8V */
 
 	/* poll VOSF bit in PWR_CSR. Wait until it is reset to 0 */
@@ -161,23 +158,42 @@ ao_clock_init(void)
 	while ((stm_pwr.csr & (1 << STM_PWR_CSR_VOSF)) != 0)
 		asm("nop");
 
+#if AO_HSE
+	/* Enable HSE clock */
+	if (!(stm_rcc.cr & (1 << STM_RCC_CR_HSERDY))) {
+		stm_rcc.cr |= (1 << STM_RCC_CR_HSEON);
+		while (!(stm_rcc.cr & (1 << STM_RCC_CR_HSERDY)))
+			asm("nop");
+	}
+#define STM_RCC_CFGR_SWS_TARGET_CLOCK		(STM_RCC_CFGR_SWS_HSE << STM_RCC_CFGR_SWS)
+#define STM_RCC_CFGR_SW_TARGET_CLOCK		(STM_RCC_CFGR_SW_HSE)
+#define STM_PLLSRC				AO_HSE
+#define STM_RCC_CFGR_PLLSRC_TARGET_CLOCK	(1 << STM_RCC_CFGR_PLLSRC)
+#else
+#define STM_HSI 				16000000
+#define STM_RCC_CFGR_SWS_TARGET_CLOCK		(STM_RCC_CFGR_SWS_HSI << STM_RCC_CFGR_SWS)
+#define STM_RCC_CFGR_SW_TARGET_CLOCK		(STM_RCC_CFGR_SW_HSI)
+#define STM_PLLSRC				STM_HSI
+#define STM_RCC_CFGR_PLLSRC_TARGET_CLOCK	(0 << STM_RCC_CFGR_PLLSRC)
+#endif
+
+#if !AO_HSE || HAS_ADC
 	/* Enable HSI RC clock 16MHz */
 	if (!(stm_rcc.cr & (1 << STM_RCC_CR_HSIRDY))) {
 		stm_rcc.cr |= (1 << STM_RCC_CR_HSION);
 		while (!(stm_rcc.cr & (1 << STM_RCC_CR_HSIRDY)))
 			asm("nop");
 	}
-#define STM_HSI 16000000
-
-	/* Switch to direct HSI for SYSCLK */
+#endif
+	/* Switch to direct high speed clock for SYSCLK */
 	if ((stm_rcc.cfgr & (STM_RCC_CFGR_SWS_MASK << STM_RCC_CFGR_SWS)) !=
-	    (STM_RCC_CFGR_SWS_HSI << STM_RCC_CFGR_SWS)) {
+	    STM_RCC_CFGR_SWS_TARGET_CLOCK) {
 		cfgr = stm_rcc.cfgr;
 		cfgr &= ~(STM_RCC_CFGR_SW_MASK << STM_RCC_CFGR_SW);
-		cfgr |= (STM_RCC_CFGR_SW_HSI << STM_RCC_CFGR_SW);
+		cfgr |= STM_RCC_CFGR_SW_TARGET_CLOCK;
 		stm_rcc.cfgr = cfgr;
 		while ((stm_rcc.cfgr & (STM_RCC_CFGR_SWS_MASK << STM_RCC_CFGR_SWS)) !=
-		       (STM_RCC_CFGR_SWS_HSI << STM_RCC_CFGR_SWS))
+		       STM_RCC_CFGR_SWS_TARGET_CLOCK);
 			asm("nop");
 	}
 
@@ -191,19 +207,12 @@ ao_clock_init(void)
 	cfgr &= ~(STM_RCC_CFGR_PLLMUL_MASK << STM_RCC_CFGR_PLLMUL);
 	cfgr &= ~(STM_RCC_CFGR_PLLDIV_MASK << STM_RCC_CFGR_PLLDIV);
 
-//	cfgr |= (STM_RCC_CFGR_PLLMUL_6 << STM_RCC_CFGR_PLLMUL);
-//	cfgr |= (STM_RCC_CFGR_PLLDIV_3 << STM_RCC_CFGR_PLLDIV);
-
-	cfgr |= (STM_RCC_CFGR_PLLMUL_6 << STM_RCC_CFGR_PLLMUL);
-	cfgr |= (STM_RCC_CFGR_PLLDIV_4 << STM_RCC_CFGR_PLLDIV);
+	cfgr |= (AO_RCC_CFGR_PLLMUL << STM_RCC_CFGR_PLLMUL);
+	cfgr |= (AO_RCC_CFGR_PLLDIV << STM_RCC_CFGR_PLLDIV);
 
-#define STM_PLLMUL	6
-#define STM_PLLDIV	4
-
-	/* PLL source to HSI */
+	/* PLL source */
 	cfgr &= ~(1 << STM_RCC_CFGR_PLLSRC);
-
-#define STM_PLLSRC	STM_HSI
+	cfgr |= STM_RCC_CFGR_PLLSRC_TARGET_CLOCK;
 
 	stm_rcc.cfgr = cfgr;
 
diff --git a/src/stm/stm32l.h b/src/stm/stm32l.h
index 39dd710d..b922b6bc 100644
--- a/src/stm/stm32l.h
+++ b/src/stm/stm32l.h
@@ -303,6 +303,9 @@ struct stm_rcc {
 
 extern struct stm_rcc stm_rcc;
 
+/* Nominal high speed internal oscillator frequency is 16MHz */
+#define STM_HSI_FREQ		16000000
+
 #define STM_RCC_CR_RTCPRE	(29)
 #define  STM_RCC_CR_RTCPRE_HSE_DIV_2	0
 #define  STM_RCC_CR_RTCPRE_HSE_DIV_4	1