I2C: Restore on F1, refactoring prep for F2.

Bring back <libmaple/i2c.h> support on STM32F1 with a view towards how
it'll be implemented on STM32F2. There are still many F1-isms in
libmaple/i2c.c and <libmaple/i2c.h>, to be dealt with subsequently.

Move device declarations and base pointer definitions to a new F1
<series/i2c.h>. The register maps and bit definitions themselves are
identical on both series, so leave them in the libmaple header.

Add i2c_private.h, which contains:

- I2C_DEV(), a convenience macro for defining an i2c_dev, and
- declarations for the event and error IRQ handlers.

The IRQ handlers are large, and I2C is slow anyway, so I see no reason
to make them inline in the private header (as we do for some other
peripherals). We just expose the existing ones that were formerly
static in libmaple/i2c.c, but prefix the names with underscore.

Move the device declarations and IRQ handlers into new
stm32f1/i2c.c. These use the i2c_private.h API.

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

1 files changed, 3 insertions, 44 deletions

diff --git a/libmaple/i2c.c b/libmaple/i2c.c
index 3db8516..5c0d5e4 100644
--- a/libmaple/i2c.c
+++ b/libmaple/i2c.c
@@ -2,6 +2,7 @@
  * The MIT License
  *
  * Copyright (c) 2010 Perry Hung.
+ * Copyright (c) 2012 LeafLabs, LLC.
  *
  * Permission is hereby granted, free of charge, to any person
  * obtaining a copy of this software and associated documentation
@@ -40,32 +41,6 @@
 
 #include <string.h>
 
-static i2c_dev i2c_dev1 = {
-    .regs         = I2C1_BASE,
-    .gpio_port    = &gpiob,
-    .sda_pin      = 7,
-    .scl_pin      = 6,
-    .clk_id       = RCC_I2C1,
-    .ev_nvic_line = NVIC_I2C1_EV,
-    .er_nvic_line = NVIC_I2C1_ER,
-    .state        = I2C_STATE_DISABLED
-};
-/** I2C1 device */
-i2c_dev* const I2C1 = &i2c_dev1;
-
-static i2c_dev i2c_dev2 = {
-    .regs         = I2C2_BASE,
-    .gpio_port    = &gpiob,
-    .sda_pin      = 11,
-    .scl_pin      = 10,
-    .clk_id       = RCC_I2C2,
-    .ev_nvic_line = NVIC_I2C2_EV,
-    .er_nvic_line = NVIC_I2C2_ER,
-    .state        = I2C_STATE_DISABLED
-};
-/** I2C2 device */
-i2c_dev* const I2C2 = &i2c_dev2;
-
 static inline int32 wait_for_state_change(i2c_dev *dev,
                                           i2c_state state,
                                           uint32 timeout);
@@ -129,7 +104,7 @@ enum {
  * @brief IRQ handler for I2C master. Handles transmission/reception.
  * @param dev I2C device
  */
-static void i2c_irq_handler(i2c_dev *dev) {
+void _i2c_irq_handler(i2c_dev *dev) {
     i2c_msg *msg = dev->msg;
 
     uint8 read = msg->flags & I2C_MSG_READ;
@@ -289,20 +264,12 @@ static void i2c_irq_handler(i2c_dev *dev) {
     }
 }
 
-void __irq_i2c1_ev(void) {
-   i2c_irq_handler(&i2c_dev1);
-}
-
-void __irq_i2c2_ev(void) {
-   i2c_irq_handler(&i2c_dev2);
-}
-
 /**
  * @brief Interrupt handler for I2C error conditions
  * @param dev I2C device
  * @sideeffect Aborts any pending I2C transactions
  */
-static void i2c_irq_error_handler(i2c_dev *dev) {
+void _i2c_irq_error_handler(i2c_dev *dev) {
     I2C_CRUMB(ERROR_ENTRY, dev->regs->SR1, dev->regs->SR2);
 
     dev->error_flags = dev->regs->SR2 & (I2C_SR1_BERR |
@@ -318,14 +285,6 @@ static void i2c_irq_error_handler(i2c_dev *dev) {
     dev->state = I2C_STATE_ERROR;
 }
 
-void __irq_i2c1_er(void) {
-    i2c_irq_error_handler(&i2c_dev1);
-}
-
-void __irq_i2c2_er(void) {
-    i2c_irq_error_handler(&i2c_dev2);
-}
-
 /**
  * @brief Reset an I2C bus.
  *