[platform][stm32] add generic gpio driver

-can be used for simple pin muxing setup as well

platform/stm32f1xx/STM32F10x_StdPeriph_Driver/inc/stm32f10x_gpio.h

@@ -347,7 +347,7 @@ typedef enum
 
 void GPIO_DeInit(GPIO_TypeDef* GPIOx);
 void GPIO_AFIODeInit(void);
-void GPIO_Init(GPIO_TypeDef* GPIOx, GPIO_InitTypeDef* GPIO_InitStruct);
+void GPIO_Init(GPIO_TypeDef* GPIOx, const GPIO_InitTypeDef* GPIO_InitStruct);
 void GPIO_StructInit(GPIO_InitTypeDef* GPIO_InitStruct);
 uint8_t GPIO_ReadInputDataBit(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin);
 uint16_t GPIO_ReadInputData(GPIO_TypeDef* GPIOx);

platform/stm32f1xx/STM32F10x_StdPeriph_Driver/src/stm32f10x_gpio.c

@@ -169,7 +169,7 @@ void GPIO_AFIODeInit(void)
   *   contains the configuration information for the specified GPIO peripheral.
   * @retval None
   */
-void GPIO_Init(GPIO_TypeDef* GPIOx, GPIO_InitTypeDef* GPIO_InitStruct)
+void GPIO_Init(GPIO_TypeDef* GPIOx, const GPIO_InitTypeDef* GPIO_InitStruct)
 {
   uint32_t currentmode = 0x00, currentpin = 0x00, pinpos = 0x00, pos = 0x00;
   uint32_t tmpreg = 0x00, pinmask = 0x00;

platform/stm32f1xx/gpio.c

@@ -0,0 +1,104 @@
+/*
+ * Copyright (c) 2012 Travis Geiselbrecht
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#include <debug.h>
+#include <assert.h>
+#include <dev/gpio.h>
+#include <platform/stm32.h>
+#include <platform/gpio.h>
+#include <stm32f10x_gpio.h>
+#include <stm32f10x_rcc.h>
+
+static GPIO_TypeDef *port_to_pointer(unsigned int port)
+{
+	switch (port) {
+		default:
+		case GPIO_PORT_A: return GPIOA;
+		case GPIO_PORT_B: return GPIOB;
+		case GPIO_PORT_C: return GPIOC;
+		case GPIO_PORT_D: return GPIOD;
+		case GPIO_PORT_E: return GPIOE;
+		case GPIO_PORT_F: return GPIOF;
+		case GPIO_PORT_G: return GPIOG;
+	}
+}
+
+static void enable_port(unsigned int port)
+{
+	DEBUG_ASSERT(port <= GPIO_PORT_G);
+
+	/* happens to be the RCC ids are sequential bits, so we can start from A and shift */
+	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA << port, ENABLE);
+}
+
+void stm32_gpio_early_init(void)
+{
+	RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);
+}
+
+int gpio_config(unsigned nr, unsigned flags)
+{
+	uint port = GPIO_PORT(nr);
+	uint pin = GPIO_PIN(nr);
+
+	enable_port(port);
+
+	GPIO_InitTypeDef init;
+	init.GPIO_Speed = GPIO_Speed_50MHz;
+
+	init.GPIO_Pin = (1 << pin);
+
+	if (flags & GPIO_STM32_AF) {
+		if (flags & GPIO_STM32_OD)
+			init.GPIO_Mode = GPIO_Mode_Out_OD;
+		else
+			init.GPIO_Mode = GPIO_Mode_AF_PP;
+	} else if (flags & GPIO_OUTPUT) {
+		if (flags & GPIO_STM32_OD)
+			init.GPIO_Mode = GPIO_Mode_Out_OD;
+		else
+			init.GPIO_Mode = GPIO_Mode_Out_PP;
+	} else { // GPIO_INPUT
+		if (flags & GPIO_PULLUP) {
+			init.GPIO_Mode = GPIO_Mode_IPU;
+		} else if (flags & GPIO_PULLDOWN) {
+			init.GPIO_Mode = GPIO_Mode_IPD;
+		} else {
+			init.GPIO_Mode = GPIO_Mode_IN_FLOATING;
+		}
+	}
+
+	GPIO_Init(port_to_pointer(port), &init);
+
+	return 0;
+}
+
+void gpio_set(unsigned nr, unsigned on)
+{
+	GPIO_WriteBit(port_to_pointer(GPIO_PORT(nr)), 1 << GPIO_PIN(nr), on);
+}
+
+int gpio_get(unsigned nr)
+{
+	return GPIO_ReadInputDataBit(port_to_pointer(GPIO_PORT(nr)), 1 << GPIO_PIN(nr));
+}
+

platform/stm32f1xx/include/platform/gpio.h

@@ -0,0 +1,25 @@
+#ifndef __PLATFORM_STM32_GPIO_H
+#define __PLATFORM_STM32_GPIO_H
+
+/* helper defines for STM32 platforms */
+
+/* flag to gpio_configure */
+#define GPIO_STM32_AF (0x1 << 16) 
+#define GPIO_STM32_OD (0x2 << 16)
+
+/* gpio port/pin is packed into a single unsigned int in 16x:8port:8pin format */
+#define GPIO(port, pin) ((unsigned int)(((port) << 8) | (pin)))
+
+#define GPIO_PORT(gpio) (((gpio) >> 8) & 0xff) 
+#define GPIO_PIN(gpio) ((gpio) & 0xff)
+
+#define GPIO_PORT_A 0
+#define GPIO_PORT_B 1
+#define GPIO_PORT_C 2
+#define GPIO_PORT_D 3
+#define GPIO_PORT_E 4
+#define GPIO_PORT_F 5
+#define GPIO_PORT_G 6
+
+#endif
+

platform/stm32f1xx/include/platform/stm32.h

@@ -27,9 +27,7 @@ void stm32_debug_early_init(void);
 void stm32_debug_init(void);
 void stm32_timer_early_init(void);
 void stm32_timer_init(void);
-
-// XXX refactor this into a proper usart driver
-void stm32_debug_rx_irq(void);
+void stm32_gpio_early_init(void);
 
 #endif
 

platform/stm32f1xx/init.c

@@ -33,6 +33,7 @@ void platform_early_init(void)
 	SystemInit();
 
 	stm32_timer_early_init();
+	stm32_gpio_early_init();
 }
 
 void platform_init(void)

platform/stm32f1xx/rules.mk

@@ -46,6 +46,7 @@ OBJS += \
 	$(LOCAL_DIR)/uart.o \
 	$(LOCAL_DIR)/timer.o \
 	$(LOCAL_DIR)/vectab.o \
+	$(LOCAL_DIR)/gpio.o \
 
 #	$(LOCAL_DIR)/debug.o \
 	$(LOCAL_DIR)/interrupts.o \