Removed stm32 rcc code. Briefly tested the basic set up procedure,

brings up the board to 72MHz, clocked by external crystal PLL boosted to
72MHz.

3 files changed, 137 insertions, 12 deletions

diff --git a/src/lib/rcc.c b/src/lib/rcc.c
index e29b010..577f6e4 100644
--- a/src/lib/rcc.c
+++ b/src/lib/rcc.c
@@ -1,19 +1,137 @@
 #include "libmaple.h"
 #include "rcc.h"
+#include "stm32f10x_flash.h"
+
+#define RCC_BASE               0x40021000
+#define RCC_CR                 (RCC_BASE + 0x0)
+#define RCC_CFGR               (RCC_BASE + 0x4)
+#define RCC_CIR                (RCC_BASE + 0x8)
+#define RCC_APB2STR            (RCC_BASE + 0xC)
+#define RCC_APB1RSTR           (RCC_BASE + 0x10)
+#define RCC_AHBENR             (RCC_BASE + 0x14)
+#define RCC_APB2ENR            (RCC_BASE + 0x18)
+#define RCC_APB1ENR            (RCC_BASE + 0x1C)
+#define RCC_BDCR               (RCC_BASE + 0x20)
+#define RCC_CSR                (RCC_BASE + 0x24)
+#define RCC_AHBSTR             (RCC_BASE + 0x28)
+#define RCC_CFGR2              (RCC_BASE + 0x2C))
+
+#define HSEON                 BIT(16)
+
+#define HSERDY            *(volatile uint32_t*)(BITBAND_PERI(RCC_CR + 2, 0))
+
+#define HPRE                          0x000000F0
+#define PPRE                          0x00000700
+#define PLLMUL                        0x002C0000
+#define PLL_MUL_9                     0x001C0000
+#define PLLSRC                        BIT(16)
+#define SYSCLK_DIV_1                  (0x0 << 4)
+#define HCLK_DIV_1                    0
+#define HCLK_DIV_2                    0x00000400
+
+#define PLLRDY                       BIT(25)
+#define PLLON                         BIT(24)
+#define PLL_INPUT_CLK_HSE             BIT(16)
+
+
+static void set_ahb_prescaler(uint32_t divider) {
+    uint32_t tmp = __read(RCC_CFGR);
+
+    switch (divider) {
+    case SYSCLK_DIV_1:
+        tmp &= ~HPRE;
+        tmp |= SYSCLK_DIV_1;
+        break;
+    default:
+        ASSERT(0);
+    }
+
+    __write(RCC_CFGR, tmp);
+}
+
+static void set_apb1_prescaler(uint32_t divider) {
+    uint32_t tmp = __read(RCC_CFGR);
+
+    switch (divider) {
+    case HCLK_DIV_2:
+        tmp &= ~PPRE;
+        tmp |= HCLK_DIV_2;
+        break;
+    default:
+        ASSERT(0);
+    }
+
+    __write(RCC_CFGR, tmp);
+}
+
+static void set_apb2_prescaler(uint32_t divider) {
+    uint32_t tmp = __read(RCC_CFGR);
+
+    switch (divider) {
+    case HCLK_DIV_1:
+        break;
+    default:
+        ASSERT(0);
+    }
+}
+
+static void pll_init(void) {
+    uint32_t tmp;
+
+    /* set pll multiplier to 9 */
+    tmp = __read(RCC_CFGR);
+    tmp &= ~PLLMUL;
+    tmp |= PLL_MUL_9;
+
+    /* set pll clock to be hse */
+    tmp |= PLL_INPUT_CLK_HSE;
+    __write(RCC_CFGR, tmp);
+
+    /* turn on the pll  */
+    __set_bits(RCC_CR, PLLON);
+
+    while(!__get_bits(RCC_CR, PLLRDY)) {
+        asm volatile("nop");
+    }
+
+    /* select pll for system clock source  */
+    tmp = __read(RCC_CFGR);
+    tmp &= ~0x3;
+    tmp |= 0x2;
+    __write(RCC_CFGR, tmp);
+
+    while (__get_bits(RCC_CFGR, 0x00000008) != 0x8) {
+        asm volatile("nop");
+    }
+}
 
-typedef struct RCC {
-    volatile uint32 CR;
-    volatile uint32 CFGR;
-    volatile uint32 CIR;
-    volatile uint32 APB2STR;
-    volatile uint32 APB1RSTR;
-    volatile uint32 AHBENR;
-    volatile uint32 APB2ENR;
-    volatile uint32 APB1ENR;
-    volatile uint32 BDCR;
-    volatile uint32 CSR;
-} RCC;
 
 void rcc_enable(uint32 p) {
+}
+
+void rcc_init(void) {
+
+
+__set_bits(RCC_CR, HSEON);
+
+    while (!HSERDY) {
+        asm volatile("nop");
+    }
+
+      /* Enable Prefetch Buffer */
+      FLASH_PrefetchBufferCmd( (u32)FLASH_PrefetchBuffer_Enable);
+
+      /* Flash 2 wait state */
+      FLASH_SetLatency(FLASH_Latency_2);
+
+      set_ahb_prescaler(SYSCLK_DIV_1);
+      set_apb1_prescaler(HCLK_DIV_2);
+      set_apb2_prescaler(HCLK_DIV_1);
+
+   pll_init();
 
+    __set_bits(RCC_APB2ENR, BIT(2));
+    __set_bits(RCC_APB2ENR, BIT(3));
+    __set_bits(RCC_APB2ENR, BIT(4));
+    __set_bits(RCC_APB2ENR, BIT(5));
 }
diff --git a/src/lib/rcc.h b/src/lib/rcc.h
index 2338593..f06fb5f 100644
--- a/src/lib/rcc.h
+++ b/src/lib/rcc.h
@@ -13,6 +13,7 @@
 #define    RCC_TIMER4
 
 void rcc_enable(uint32 p);
+void rcc_init(void);
 
 #endif
 
diff --git a/src/lib/util.h b/src/lib/util.h
index e425cc0..c1ba15d 100644
--- a/src/lib/util.h
+++ b/src/lib/util.h
@@ -54,6 +54,12 @@
 
 #define REG_GET(reg)                    *(volatile uint32_t*)(reg)
 
+#define __set_bits(addr, mask)          *(volatile uint32_t*)(addr) |= (uint32_t)(mask)
+#define __clear_bits(addr, mask)        (*(volatile uint32_t*)(addr) &= (uint32_t)~(mask))
+#define __get_bits(addr, mask)          (*(volatile uint32_t*)(addr) & (uint32_t)(mask))
+
+#define __read(reg)                     *(volatile uint32_t*)(reg)
+#define __write(reg, value)             *(volatile uint32_t*)(reg) = (value)
 
 #ifdef __cplusplus
 extern "C"{