Merge pull request #1850 from wuhanstudio/upstream-stm32f10x

Add I2C bus driver for stm32f10x

bsp/stm32f10x/drivers/Kconfig

+config BSP_USING_I2C
+    bool "Enable I2C1  (PB6/7)"
+    default n
+    select RT_USING_I2C
+    select RT_USING_I2C_BITOPS
+
 config RT_USING_UART1
     bool "Enable UART1 (PA9/10)"
     default y

bsp/stm32f10x/drivers/SConscript

@@ -15,6 +15,9 @@ usart.c
 if GetDepend(['RT_USING_PIN']):
     src += ['gpio.c']
 
+if GetDepend(['BSP_USING_I2C']):
+    src += ['i2c.c']
+
 # add canbus driver.
 if GetDepend('RT_USING_CAN'):
     src += ['bxcan.c']

bsp/stm32f10x/drivers/i2c.c

+#include "i2c.h"
+#include <stm32f10x.h>
+
+void stm32_set_sda(void *data, rt_int32_t state)
+{
+    if(state == 1)
+        GPIO_SetBits(I2C1_GPIO , I2C1_GPIO_SDA);   //GPIOB->BSRRL = I2C1_GPIO_SDA
+    else if(state == 0)
+        GPIO_ResetBits(I2C1_GPIO , I2C1_GPIO_SDA); //GPIOB->BSRRH = I2C1_GPIO_SDA
+}
+
+void stm32_set_scl(void *data, rt_int32_t state)
+{
+    if(state == 1)
+        GPIO_SetBits(I2C1_GPIO , I2C1_GPIO_SCL);   //GPIOB->BSRRL = I2C1_GPIO_SCL
+    else if(state == 0)
+        GPIO_ResetBits(I2C1_GPIO , I2C1_GPIO_SCL); //GPIOB->BSRRH = I2C1_GPIO_SCL
+}
+
+rt_int32_t stm32_get_sda(void *data)
+{
+    return (rt_int32_t)GPIO_ReadInputDataBit(I2C1_GPIO , I2C1_GPIO_SDA); //return(GPIOB->IDR  & I2C1_GPIO_SDA)
+}
+
+rt_int32_t stm32_get_scl(void *data)
+{
+    return (rt_int32_t)GPIO_ReadInputDataBit(I2C1_GPIO , I2C1_GPIO_SCL); //return(GPIOB->IDR  & I2C1_GPIO_SCL)
+}
+
+void stm32_udelay(rt_uint32_t us)
+{
+    rt_uint32_t delta;
+    /* sysTick->LOAD=21000, RT_TICK_PER_SECOND=1000 */
+    us = us * (SysTick->LOAD/(1000000/RT_TICK_PER_SECOND));
+    delta = SysTick->VAL;
+    /* delay us */
+    while (delta - SysTick->VAL< us);
+}
+
+void stm32_mdelay(rt_uint32_t ms)
+{
+    stm32_udelay(ms * 1000);
+}
+
+static const struct  rt_i2c_bit_ops stm32_i2c_bit_ops =
+{
+    (void*)0xaa,     //no use in set_sda,set_scl,get_sda,get_scl
+    stm32_set_sda,
+    stm32_set_scl,
+    stm32_get_sda,
+    stm32_get_scl,
+    stm32_udelay,
+    20,
+};
+
+static void RCC_Configuration(void)
+{
+   RCC->APB2ENR|=1<<4;
+   RCC_APB2PeriphClockCmd( RCC_I2C, ENABLE );
+}
+
+
+static void GPIO_Configuration(void)
+{
+    GPIO_InitTypeDef GPIO_InitStructure;
+    GPIO_InitStructure.GPIO_Pin = I2C1_GPIO_SDA | I2C1_GPIO_SCL;
+    GPIO_InitStructure.GPIO_Mode =GPIO_Mode_Out_OD ;
+    GPIO_InitStructure.GPIO_Speed =GPIO_Speed_50MHz;
+    GPIO_Init(I2C1_GPIO, &GPIO_InitStructure);
+}
+
+int rt_hw_i2c_init(void)
+{
+    static struct rt_i2c_bus_device stm32_i2c;
+
+    RCC_Configuration();
+    GPIO_Configuration();
+    
+    rt_memset((void *)&stm32_i2c, 0, sizeof(struct rt_i2c_bus_device));
+    stm32_i2c.priv = (void *)&stm32_i2c_bit_ops;
+    rt_i2c_bit_add_bus(&stm32_i2c, "i2c1");   
+        
+    return 0;
+}
+INIT_BOARD_EXPORT(rt_hw_i2c_init);  

bsp/stm32f10x/drivers/i2c.h

+#ifndef __I2C_SOFT_INIT_H__
+#define __I2C_SOFT_INIT_H__
+
+#include <rtthread.h>
+#include <rtdevice.h>
+
+#define I2C1_GPIO 		GPIOB
+#define I2C1_GPIO_SCL 	GPIO_Pin_6
+#define I2C1_GPIO_SDA 	GPIO_Pin_7
+#define RCC_I2C 		RCC_APB2Periph_GPIOB
+
+int rt_hw_i2c_init(void);
+
+void stm32_set_sda(void *data, rt_int32_t state);
+void stm32_set_scl(void *data, rt_int32_t state);
+rt_int32_t stm32_get_sda(void *data);
+rt_int32_t stm32_get_scl(void *data);
+
+void stm32_udelay(rt_uint32_t us);
+void stm32_mdelay(rt_uint32_t ms);
+
+static void RCC_Configuration(void);
+static void GPIO_Configuration(void);
+
+#endif