RCC: Add new mechanism for configuring the main PLL.

The new style for configuring the PLL is to initialize
a (series-specific) struct rcc_pll_cfg, and pass a pointer to it to
rcc_configure_pll(). After that's done, you can use
rcc_turn_on_clk(RCC_CLK_PLL) to turn on the main PLL, and busy-wait
until rcc_is_clk_ready(RCC_CLK_PLL) is true to make sure the new
configuration took effect.

- libmaple/rcc.h:

  -- Add struct rcc_pll_cfg, which specifies a PLL configuration. This
     specifies a PLL source and a void pointer to series-specific PLL
     configuration data.

  -- Add rcc_configure_pll(), which takes a pointer to struct
     rcc_pll_cfg, and configures the main PLL. It's up to each series
     to define this function.

- stm32f1/rcc.h: Add struct stm32f1_rcc_pll_data, to store F1-specific
  PLL configuration state.

- stm32f1/rcc.c: Add an implementation for rcc_configure_pll().

- stm32f2/rcc.h: Add struct stm32f2_rcc_pll_data, to store F2-specific
  PLL configuration data.

- stm32f2/rcc.c: Add an implementation for rcc_configure_pll().

Signed-off-by: Marti Bolivar <mbolivar@leaflabs.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/libmaple/include/libmaple/rcc.h b/libmaple/include/libmaple/rcc.h
index 4a22b5e..2c8776b 100644
--- a/libmaple/include/libmaple/rcc.h
+++ b/libmaple/include/libmaple/rcc.h
@@ -80,12 +80,30 @@ typedef enum rcc_sysclk_src {
  */
 
 /* Clock prescaler management. */
+
 void rcc_set_prescaler(rcc_prescaler prescaler, uint32 divider);
 
 /* SYSCLK. */
+
 void rcc_switch_sysclk(rcc_sysclk_src sysclk_src);
 
+/* PLL configuration */
+
+/**
+ * @brief Specifies a configuration for the main PLL.
+ */
+typedef struct rcc_pll_cfg {
+    rcc_pllsrc  pllsrc;     /**< PLL source */
+    void       *data;       /**< Series-specific configuration
+                             * data. See the <series/rcc.h> for your
+                             * MCU for more information on what to put
+                             * here. */
+} rcc_pll_cfg;
+
+void rcc_configure_pll(rcc_pll_cfg *pll_cfg);
+
 /* System and secondary clock sources. */
+
 void rcc_turn_on_clk(rcc_clk clock);
 void rcc_turn_off_clk(rcc_clk clock);
 int rcc_is_clk_ready(rcc_clk clock);