Add support for linux i2c userspace

.gitignore

@@ -0,0 +1,2 @@
+*.o
+*.~

sys/linux-i2c/128x32-oled/main.c

@@ -0,0 +1,43 @@
+#include <linux-i2c.h>
+#include <u8g2.h>
+#include <stdio.h>
+
+#define SSD1306_ADDR  0x3c
+
+u8g2_t u8g2;
+
+int main (void)
+{
+//	u8g2_Setup_ssd1305_i2c_128x32_noname_1(&u8g2, U8G2_R0, u8x8_byte_linux_i2c, u8x8_linux_i2c_delay);
+//	u8g2_Setup_ssd1305_i2c_128x32_adafruit_1(&u8g2, U8G2_R0, u8x8_byte_linux_i2c, u8x8_linux_i2c_delay);
+        u8g2_Setup_ssd1306_i2c_128x32_univision_1(&u8g2, U8G2_R0, u8x8_byte_linux_i2c, u8x8_linux_i2c_delay);
+	
+//	u8g2_Setup_ssd1305_i2c_128x32_noname_2(&u8g2, U8G2_R0, u8x8_byte_linux_i2c, u8x8_linux_i2c_delay);
+// 	u8g2_Setup_ssd1305_i2c_128x32_adafruit_2(&u8g2, U8G2_R0, u8x8_byte_linux_i2c, u8x8_linux_i2c_delay);
+//     u8g2_Setup_ssd1306_i2c_128x32_univision_2(&u8g2, U8G2_R0, u8x8_byte_linux_i2c, u8x8_linux_i2c_delay);
+	
+// 	u8g2_Setup_ssd1305_i2c_128x32_noname_f(&u8g2, U8G2_R0, u8x8_byte_linux_i2c, u8x8_linux_i2c_delay);
+// 	u8g2_Setup_ssd1305_i2c_128x32_adafruit_f(&u8g2, U8G2_R0, u8x8_byte_linux_i2c, u8x8_linux_i2c_delay);
+//     u8g2_Setup_ssd1306_i2c_128x32_univision_f(&u8g2, U8G2_R0, u8x8_byte_linux_i2c, u8x8_linux_i2c_delay);
+
+	u8g2_SetI2CAddress(&u8g2, SSD1306_ADDR);
+
+	u8g2_InitDisplay(&u8g2);
+
+	u8g2_SetPowerSave(&u8g2, 0);
+
+	u8g2_ClearBuffer(&u8g2);
+
+	u8g2_SetFont(&u8g2, u8g2_font_smart_patrol_nbp_tr);
+
+	u8g2_SetFontRefHeightText(&u8g2);
+
+	u8g2_SetFontPosTop(&u8g2);
+
+	u8g2_DrawStr(&u8g2, 0, 15, "u8g2 Linux I2C");
+
+	u8g2_SendBuffer(&u8g2);
+
+}
+
+

sys/linux-i2c/common/linux-i2c.c

@@ -0,0 +1,125 @@
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/i2c-dev.h>
+#include <linux/i2c-dev.h>
+#include <i2c/smbus.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <time.h>
+#include <u8x8.h>
+#include <unistd.h>
+
+
+#define BUFSIZ_I2C 32
+
+char filename[255];
+uint8_t data[BUFSIZ_I2C]; // just to be sure
+int idx = 0;
+// almost certainly the wrong place for this state!
+int file = 1;
+uint8_t addr = 0x3c;
+int adapter_nr = 0; /* probably dynamically determined */
+
+
+uint8_t
+u8x8_byte_linux_i2c(u8x8_t *u8x8,
+		    uint8_t msg,
+		    uint8_t arg_int,
+		    void *arg_ptr)
+{
+	
+	
+	switch(msg){
+	case U8X8_MSG_BYTE_SEND:
+		//fprintf(stderr, "-- %d bytes:\n", arg_int);
+		for(int i = 0; i < arg_int && idx < BUFSIZ_I2C; i++, idx++){
+			data[idx] = *(uint8_t *)(arg_ptr+i);
+			//fprintf(stderr, "    %d  %d:  %0x\n", i, idx, data[idx]);
+		}
+		break;
+	case U8X8_MSG_BYTE_INIT:
+		// ths open/setup? it seems to be a one-time setup
+		snprintf(filename, 19, "/dev/i2c-%d", adapter_nr);
+		file = open(filename, O_RDWR);
+		if (file < 0) {
+			fprintf(stderr, "can't open i2c\n");
+			return(errno); 
+		}
+		fprintf(stderr, "opened i2c file %d\n", file);
+		if (ioctl(file, I2C_SLAVE, addr) < 0) { // u8x8_GetI2CAddress(u8x8)
+			fprintf(stderr, "can't set addr %0x\n", addr);
+			return(errno);
+		}
+		fprintf(stderr, "set i2c addr %0x\n", addr);
+		break;
+	case U8X8_MSG_BYTE_SET_DC:
+		/* ignored for i2c */
+		//fprintf(stderr, "++ set dc?\n");
+		break;
+	case U8X8_MSG_BYTE_START_TRANSFER:
+		//fprintf(stderr, "++ start transfer, resetting buffers\n");
+		memset(data, 0, BUFSIZ_I2C);
+		idx = 0;
+		break;
+	case U8X8_MSG_BYTE_END_TRANSFER:
+		//fprintf(stderr, "++ end transfer, sending cmd %0x %0x count %d\n", data[0], data[1], idx);
+		// NB! note the extre _i2c_ in there! leave that out and you are screwed
+		if (i2c_smbus_write_i2c_block_data(file, data[0], idx - 1, &data[1]) < 0) {
+			fprintf(stderr, "can't write cmd %0x: %s\n",  data[0], strerror(errno));
+			return(errno); 
+		}
+		break;
+	default:
+		fprintf(stderr, "unknown msg type %d\n", msg);
+		return 0;
+	}
+	return 1;
+}
+
+
+uint8_t
+u8x8_linux_i2c_delay(u8x8_t *u8x8,
+		     uint8_t msg,
+		     uint8_t arg_int,
+		     void *arg_ptr)
+{
+	struct timespec req;
+	struct timespec rem;
+	int ret;
+
+	req.tv_sec = 0;
+	
+	switch(msg) {
+	case U8X8_MSG_DELAY_NANO:  // delay arg_int * 1 nano second
+		req.tv_nsec = arg_int;
+		break;
+	case U8X8_MSG_DELAY_100NANO:       // delay arg_int * 100 nano seconds
+		req.tv_nsec = arg_int * 100;
+		break;
+	case U8X8_MSG_DELAY_10MICRO: // delay arg_int * 10 micro seconds
+		req.tv_nsec = arg_int * 10000;
+		break;
+	case U8X8_MSG_DELAY_MILLI:  // delay arg_int * 1 milli second
+		req.tv_nsec = arg_int * 1000000;
+		break;
+	default:
+		return 0;
+	}
+
+	while((ret = nanosleep(&req, &rem)) && errno == EINTR){
+		struct timespec tmp = req;
+		req = rem;
+		rem = tmp;
+	}
+	if (ret) {
+		perror("nanosleep");
+		fprintf(stderr, "can't sleep\n");
+		return(errno);
+	}
+	
+	return 1;
+}

sys/linux-i2c/common/linux-i2c.h

@@ -0,0 +1,25 @@
+#ifndef _LINUX_I2C_H
+#define _LINUX_I2C_H	1
+
+
+
+
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/i2c-dev.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <time.h>
+#include <u8x8.h>
+#include <unistd.h>
+
+
+uint8_t u8x8_byte_linux_i2c(u8x8_t *u8x8, uint8_t msg, uint8_t arg_int, void *arg_ptr);
+
+uint8_t u8x8_linux_i2c_delay (u8x8_t * u8x8, uint8_t msg, uint8_t arg_int, void *arg_ptr) ;
+
+
+#endif // LINUXi2c