Merge pull request #840 from caogos/master

[BSP] Add I2C driver for Loongson 1C.

bsp/ls1cdev/libraries/ls1c_gpio.c

@@ -211,8 +211,8 @@ unsigned int gpio_get(unsigned int gpio)
  */
 void gpio_set_irq_type(unsigned int gpio, gpio_irq_type_t type)
 {
-    volatile unsigned int *int_pol;     // 中断极性选择寄存器
+    volatile unsigned int *int_pol = NULL;     // 中断极性选择寄存器
-    volatile unsigned int *int_edge;    // 中断边沿选择寄存器
+    volatile unsigned int *int_edge = NULL;    // 中断边沿选择寄存器
     unsigned int port = GPIO_GET_PORT(gpio);
     unsigned int pin  = GPIO_GET_PIN(gpio);
 
@@ -257,6 +257,9 @@ void gpio_set_irq_type(unsigned int gpio, gpio_irq_type_t type)
             *int_pol    &= ~(1 << pin);
             *int_edge   &= ~(1 << pin);
             break;
+
+        default:
+            break;
     }
 
     return ;

bsp/ls1cdev/libraries/ls1c_i2c.c

@@ -0,0 +1,373 @@
+/*
+ * File      : ls1c_i2c.c
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2006 - 2012, RT-Thread Development Team
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2017-09-06     勤为本       first version
+ */
+
+// 封装硬件i2c接口
+
+
+#include "ls1c_public.h"
+#include "ls1c_regs.h"
+#include "ls1c_clock.h"
+#include "ls1c_i2c.h"
+#include "ls1c_delay.h"
+
+
+
+/*
+ * I2C各个寄存器相对基地址的偏移
+ * 发送数据寄存器和接收数据寄存器的偏移是相同的
+ * 命令寄存器和状态寄存器的偏移是相同的，不同的是命令寄存器只写，状态寄存器只读
+ */
+#define LS1C_I2C_PRER_LOW_OFFSET            (0)     // 分频锁存器低字节寄存器偏移
+#define LS1C_I2C_PRER_HIGH_OFFSET           (1)     // 分频锁存器高字节寄存器偏移
+#define LS1C_I2C_CONTROL_OFFSET             (2)     // 控制寄存器偏移
+#define LS1C_I2C_DATA_OFFSET                (3)     // 发送数据寄存器和接收数据寄存器的偏移是相同的
+#define LS1C_I2C_CMD_OFFSET                 (4)     // 命令寄存器偏移，只写
+#define LS1C_I2C_STATUS_OFFSET              (4)     // 状态寄存器偏移，只读
+
+
+// 控制寄存器的位域
+#define LS1C_I2C_CONTROL_EN                 (0x80)  // i2c模块使能
+#define LS1C_I2C_CONTROL_IEN                (0x40)  // 中断使能
+
+// 命令寄存器的位域
+#define LS1C_I2C_CMD_START                  (0x90)  // 产生START信号
+#define LS1C_I2C_CMD_STOP                   (0x40)  // 产生STOP信号
+#define LS1C_I2C_CMD_READ                   (0x20)  // 产生读信号，即产生ACK信号
+#define LS1C_I2C_CMD_WRITE                  (0x10)  // 产生写信号
+#define LS1C_I2C_CMD_READ_ACK               (0x20)  // 产生ACK信号，与读信号相同
+#define LS1C_I2C_CMD_READ_NACK              (0x28)  // 产生NACK信号
+#define LS1C_I2C_CMD_IACK                   (0x00)  // 产生中断应答信号
+
+// 状态寄存器的位域
+#define LS1C_I2C_STATUS_IF                  (0x01)  // 中断标志位
+#define LS1C_I2C_STATUS_TIP                 (0x02)  // 指示传输的过程。1，正在传输；0，传输完成
+#define LS1C_I2C_STATUS_ARBLOST             (0x20)  // I2C核失去I2C总线的控制权
+#define LS1C_I2C_STATUS_BUSY                (0x40)  // I2C总线忙标志
+#define LS1C_I2C_STATUS_NACK                (0x80)  // 应答位标志。1，没收到应答位；0，收到应答位
+
+
+/*
+ * 获取指定i2c模块的基地址
+ * @I2Cx I2C模块的编号
+ */
+void *i2c_get_base(ls1c_i2c_t I2Cx)
+{
+    void *base = NULL;
+    
+    switch (I2Cx)
+    {
+        case LS1C_I2C_0:
+            base = (void *)LS1C_I2C0_BASE;
+            break;
+
+        case LS1C_I2C_1:
+            base = (void *)LS1C_I2C1_BASE;
+            break;
+
+        case LS1C_I2C_2:
+            base = (void *)LS1C_I2C2_BASE;
+            break;
+
+        default:
+            base = NULL;
+            break;
+    }
+
+    return base;
+}
+
+
+/*
+ * 向命令寄存器写命令
+ * @i2c_info_p i2c模块信息
+ * @cmd 命令
+ */
+void i2c_cmd(ls1c_i2c_info_t *i2c_info_p, unsigned char cmd)
+{
+    void *i2c_base = i2c_get_base(i2c_info_p->I2Cx);
+
+    reg_write_8(cmd, i2c_base + LS1C_I2C_CMD_OFFSET);
+
+    return ;
+}
+
+
+/*
+ * 执行START命令，发送START信号
+ * @i2c_info_p i2c模块信息
+ */
+void i2c_cmd_start(ls1c_i2c_info_t *i2c_info_p)
+{
+    i2c_cmd(i2c_info_p, LS1C_I2C_CMD_START);
+    return ;
+}
+
+
+/*
+ * 执行STOP命令，发送STOP信号
+ * @i2c_info_p i2c模块信息
+ */
+void i2c_cmd_stop(ls1c_i2c_info_t *i2c_info_p)
+{
+    i2c_cmd(i2c_info_p, LS1C_I2C_CMD_STOP);
+    return ;
+}
+
+
+/*
+ * 执行写命令
+ * @i2c_info_p i2c模块信息
+ */
+void i2c_cmd_write(ls1c_i2c_info_t *i2c_info_p)
+{
+    i2c_cmd(i2c_info_p, LS1C_I2C_CMD_WRITE);
+    return ;
+}
+
+
+/*
+ * 执行读ack命令，发送读ack信号
+ * @i2c_info_p i2c模块信息
+ */
+void i2c_cmd_read_ack(ls1c_i2c_info_t *i2c_info_p)
+{
+    i2c_cmd(i2c_info_p, LS1C_I2C_CMD_READ_ACK);
+    return ;
+}
+
+
+/*
+ * 执行读nack命令,发送读nack信号
+ * @i2c_info_p i2c模块信息
+ */
+void i2c_cmd_read_nack(ls1c_i2c_info_t *i2c_info_p)
+{
+    i2c_cmd(i2c_info_p, LS1C_I2C_CMD_READ_NACK);
+    return ;
+}
+
+
+/*
+ * 发送中断应答信号
+ * @i2c_info_p i2c模块信息
+ */
+void i2c_cmd_iack(ls1c_i2c_info_t *i2c_info_p)
+{
+    i2c_cmd(i2c_info_p, LS1C_I2C_CMD_IACK);
+    return ;
+}
+
+
+/*
+ * 获取状态寄存器的值
+ * @i2c_info_p i2c模块信息
+ * @ret 状态寄存器的值
+ */
+unsigned char i2c_get_status(ls1c_i2c_info_t *i2c_info_p)
+{
+    void *i2c_base = i2c_get_base(i2c_info_p->I2Cx);
+
+    return reg_read_8(i2c_base + LS1C_I2C_STATUS_OFFSET);
+}
+
+
+/*
+ * Poll the i2c status register until the specified bit is set.
+ * Returns 0 if timed out (100 msec).
+ * @i2c_info_p i2c模块信息
+ * @bit 寄存器的某一位
+ * @ret true or false
+ */
+int i2c_poll_status(ls1c_i2c_info_t *i2c_info_p, unsigned long bit)
+{
+    int loop_cntr = 20000;
+
+    do {
+        delay_us(1);
+    } while ((i2c_get_status(i2c_info_p) & bit) && (0 < --loop_cntr));
+
+    return (0 < loop_cntr);
+}
+
+
+/*
+ * 初始化指定i2c模块
+ * @i2c_info_p 某个i2c模块的信息
+ */
+void i2c_init(ls1c_i2c_info_t *i2c_info_p)
+{
+    void *i2c_base = i2c_get_base(i2c_info_p->I2Cx);
+    unsigned long i2c_clock = i2c_info_p->clock;
+    unsigned char ctrl = reg_read_8(i2c_base + LS1C_I2C_CONTROL_OFFSET);
+    unsigned long prescale = 0;
+
+    /* make sure the device is disabled */
+    ctrl = ctrl & ~(LS1C_I2C_CONTROL_EN | LS1C_I2C_CONTROL_IEN);
+    reg_write_8(ctrl, i2c_base + LS1C_I2C_CONTROL_OFFSET);
+
+    // 设置时钟
+    i2c_clock = MIN(i2c_clock, LS1C_I2C_CLOCK_MAX);     // 限制在最大允许范围内
+    prescale = clk_get_apb_rate();
+    prescale = (prescale / (5 * i2c_clock)) - 1;
+    reg_write_8(prescale & 0xff, i2c_base + LS1C_I2C_PRER_LOW_OFFSET);
+    reg_write_8(prescale >> 8, i2c_base + LS1C_I2C_PRER_HIGH_OFFSET);
+    
+    // 使能
+    i2c_cmd_iack(i2c_info_p);
+    ctrl = ctrl | LS1C_I2C_CONTROL_EN;
+    reg_write_8(ctrl, i2c_base + LS1C_I2C_CONTROL_OFFSET);
+
+    return ;
+}
+
+
+/*
+ * (再发送一个字节数据之后)接收从机发送的ACK信号
+ * @i2c_info_p i2c模块信息
+ * @ret LS1C_I2C_ACK or LS1C_I2C_NACK
+ */
+ls1c_i2c_ack_t i2c_receive_ack(ls1c_i2c_info_t *i2c_info_p)
+{
+    ls1c_i2c_ack_t ret = LS1C_I2C_NACK;
+    
+    if (LS1C_I2C_STATUS_NACK & i2c_get_status(i2c_info_p))
+    {
+        ret = LS1C_I2C_NACK;
+    }
+    else
+    {
+        ret = LS1C_I2C_ACK;
+    }
+
+    return ret;
+}
+
+
+/*
+ * 接收数据
+ * @i2c_info_p i2c模块信息
+ * @buf 数据缓存
+ * @len 待接收数据的长度
+ */
+ls1c_i2c_ret_t i2c_receive_data(ls1c_i2c_info_t *i2c_info_p, unsigned char *buf, int len)
+{
+    void *i2c_base = i2c_get_base(i2c_info_p->I2Cx);
+    int i = 0;
+
+    for (i=0; i<len; i++)
+    {
+        // 开始接收
+        if (i != (len - 1))
+            i2c_cmd_read_ack(i2c_info_p);
+        else 
+            i2c_cmd_read_nack(i2c_info_p);
+
+        // 等待，直到接收完成
+        if (!i2c_poll_status(i2c_info_p, LS1C_I2C_STATUS_TIP))
+            return LS1C_I2C_RET_TIMEOUT;
+
+        // 读取数据，并保存
+        *buf++ = reg_read_8(i2c_base + LS1C_I2C_DATA_OFFSET);
+    }
+
+    return LS1C_I2C_RET_OK;
+}
+
+
+/*
+ * 发送START信号和地址
+ * @i2c_info_p i2c模块信息
+ * @slave_addr 从机地址
+ * @direction 数据传输方向(读、写)
+ */
+ls1c_i2c_ret_t i2c_send_start_and_addr(ls1c_i2c_info_t *i2c_info_p, 
+                                       unsigned char slave_addr,
+                                       ls1c_i2c_direction_t direction)
+{
+    void *i2c_base = i2c_get_base(i2c_info_p->I2Cx);
+    unsigned char data = 0;
+    
+    // 等待i2c总线空闲
+    if (!i2c_poll_status(i2c_info_p, LS1C_I2C_STATUS_BUSY))
+        return LS1C_I2C_RET_TIMEOUT;
+
+    // 填充地址到数据寄存器
+    data = (slave_addr << 1) | ((LS1C_I2C_DIRECTION_READ == direction) ? 1 : 0);
+    reg_write_8(data , i2c_base + LS1C_I2C_DATA_OFFSET);
+
+    // 开始发送
+    i2c_cmd_start(i2c_info_p);
+
+    // 等待，直到发送完成
+    if (!i2c_poll_status(i2c_info_p, LS1C_I2C_STATUS_TIP))
+        return LS1C_I2C_RET_TIMEOUT;
+
+    return LS1C_I2C_RET_OK;
+}
+
+
+/*
+ * 发送数据
+ * @i2c_info_p i2c模块信息
+ * @data 待发送的数据
+ * @len 待发送数据的长度
+ */
+ls1c_i2c_ret_t i2c_send_data(ls1c_i2c_info_t *i2c_info_p, unsigned char *data, int len)
+{
+    void *i2c_base = i2c_get_base(i2c_info_p->I2Cx);
+    int i = 0;
+
+    for (i=0; i<len; i++)
+    {
+        // 将一个字节数据写入数据寄存器
+        reg_write_8(*data++, i2c_base + LS1C_I2C_DATA_OFFSET);
+
+        // 开始发送
+        reg_write_8(LS1C_I2C_CMD_WRITE, i2c_base + LS1C_I2C_CMD_OFFSET);
+
+        // 等待，直到发送完成
+        if (!i2c_poll_status(i2c_info_p, LS1C_I2C_STATUS_TIP))
+            return LS1C_I2C_RET_TIMEOUT;
+
+        // 读取应答信号
+        if (LS1C_I2C_ACK != i2c_receive_ack(i2c_info_p))
+            return len;
+    }
+
+    return LS1C_I2C_RET_OK;
+}
+
+
+
+/*
+ * 发送STOP信号
+ * @i2c_info_p i2c模块信息
+ */
+void i2c_send_stop(ls1c_i2c_info_t *i2c_info_p)
+{
+    i2c_cmd_stop(i2c_info_p);
+    return ;
+}
+
+

bsp/ls1cdev/libraries/ls1c_i2c.h

@@ -0,0 +1,134 @@
+/*
+ * File      : ls1c_i2c.h
+ * This file is part of RT-Thread RTOS
+ * COPYRIGHT (C) 2006 - 2012, RT-Thread Development Team
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Change Logs:
+ * Date           Author       Notes
+ * 2017-09-06     勤为本       first version
+ */
+
+
+// 硬件i2c接口的头文件
+
+#ifndef __OPENLOONGSON_I2C_H
+#define __OPENLOONGSON_I2C_H
+
+
+
+// I2C的时钟频率
+#define LS1C_I2C_CLOCK_DEFAULT              (100000)  // Hz. 默认频率
+#define LS1C_I2C_CLOCK_MAX                  (400000)  // Hz, max 400 Kbits/sec
+
+
+// I2C模块编号
+typedef enum
+{
+    LS1C_I2C_0 = 0,
+    LS1C_I2C_1,
+    LS1C_I2C_2
+}ls1c_i2c_t;
+
+
+// I2C数据传输方向
+typedef enum
+{
+    LS1C_I2C_DIRECTION_WRITE = 0,       // 主机向从机写信息
+    LS1C_I2C_DIRECTION_READ,            // 主机向从机读信息
+}ls1c_i2c_direction_t;
+
+
+// 硬件I2C信息
+typedef struct
+{
+    ls1c_i2c_t I2Cx;                    // i2c模块编号
+    unsigned long clock;                // i2c时钟频率，单位hz
+}ls1c_i2c_info_t;
+
+
+// I2C应答
+typedef enum
+{
+    LS1C_I2C_ACK = 0,                   // 收到应答
+    LS1C_I2C_NACK = 1,                  // 没收到应答
+}ls1c_i2c_ack_t;
+
+
+// 函数返回值
+typedef enum
+{
+    LS1C_I2C_RET_OK = 0,                // OK
+    LS1C_I2C_RET_TIMEOUT,               // 超时
+}ls1c_i2c_ret_t;
+
+
+
+/*
+ * 初始化指定i2c模块
+ * @i2c_info_p 某个i2c模块的信息
+ */
+void i2c_init(ls1c_i2c_info_t *i2c_info_p);
+
+
+/*
+ * (再发送一个字节数据之后)接收从机发送的ACK信号
+ * @i2c_info_p i2c模块信息
+ * @ret LS1C_I2C_ACK or LS1C_I2C_NACK
+ */
+ls1c_i2c_ack_t i2c_receive_ack(ls1c_i2c_info_t *i2c_info_p);
+
+
+/*
+ * 接收数据
+ * @i2c_info_p i2c模块信息
+ * @buf 数据缓存
+ * @len 待接收数据的长度
+ */
+ls1c_i2c_ret_t i2c_receive_data(ls1c_i2c_info_t *i2c_info_p, unsigned char *buf, int len);
+
+
+
+/*
+ * 发送START信号和地址
+ * @i2c_info_p i2c模块信息
+ * @slave_addr 从机地址
+ * @direction 数据传输方向(读、写)
+ */
+ls1c_i2c_ret_t i2c_send_start_and_addr(ls1c_i2c_info_t *i2c_info_p, 
+                                       unsigned char slave_addr,
+                                       ls1c_i2c_direction_t direction);
+
+
+/*
+ * 发送数据
+ * @i2c_info_p i2c模块信息
+ * @data 待发送的数据
+ * @len 待发送数据的长度
+ */
+ls1c_i2c_ret_t i2c_send_data(ls1c_i2c_info_t *i2c_info_p, unsigned char *data, int len);
+
+
+/*
+ * 发送STOP信号
+ * @i2c_info_p i2c模块信息
+ */
+void i2c_send_stop(ls1c_i2c_info_t *i2c_info_p);
+
+
+
+#endif
+

bsp/ls1cdev/libraries/ls1c_public.c

@@ -54,6 +54,28 @@ unsigned int reg_get_bit(volatile unsigned int *reg, unsigned int bit)
 }
 
 
+/*
+ * 向寄存器中写入8bit(一个字节)数据
+ * @data 待写入的数据
+ * @addr 寄存器地址
+ */
+void reg_write_8(unsigned char data, volatile unsigned char *addr)
+{
+    *addr = data;
+}
+
+
+/*
+ * 从寄存器读出8bit(一个字节)数据
+ * @addr 寄存器地址
+ * @ret 读出的数据
+ */
+unsigned char reg_read_8(volatile unsigned char *addr)
+{
+    return (*addr);
+}
+
+
 /*
  * 向寄存器中写一个32bit的数据
  * @data 待写入的数据

bsp/ls1cdev/libraries/ls1c_public.h

@@ -57,6 +57,22 @@ void reg_clr_one_bit(volatile unsigned int *reg, unsigned int bit);
 unsigned int reg_get_bit(volatile unsigned int *reg, unsigned int bit);
 
 
+/*
+ * 向寄存器中写入8bit(一个字节)数据
+ * @data 待写入的数据
+ * @addr 寄存器地址
+ */
+void reg_write_8(unsigned char data, volatile unsigned char *addr);
+
+
+/*
+ * 从寄存器读出8bit(一个字节)数据
+ * @addr 寄存器地址
+ * @ret 读出的数据
+ */
+unsigned char reg_read_8(volatile unsigned char *addr);
+
+
 /*
  * 向寄存器中写一个32bit的数据
  * @data 待写入的数据

bsp/ls1cdev/libraries/ls1c_regs.h

@@ -111,6 +111,11 @@
 #define LS1C_INT4_EDGE                      (0xbfd010b4)
 
 
+// I2C寄存器
+#define LS1C_I2C0_BASE                      (0xbfe58000)
+#define LS1C_I2C1_BASE                      (0xbfe68000)
+#define LS1C_I2C2_BASE                      (0xbfe70000)
+
 
 #endif