Diff: u8glibARM/u8g_com_raspberrypi_ssd_i2c.c

Revision:

0:d8f4c441e032

diff -r 000000000000 -r d8f4c441e032 u8glibARM/u8g_com_raspberrypi_ssd_i2c.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/u8glibARM/u8g_com_raspberrypi_ssd_i2c.c	Fri Jun 10 15:20:20 2016 +0000
@@ -0,0 +1,177 @@
+/*  
+  Special pin usage:
+    U8G_PI_I2C_OPTION	additional options
+    U8G_PI_A0_STATE	used to store the last value of the command/data register selection
+    U8G_PI_SET_A0		1: Signal request to update I2C device with new A0_STATE, 0: Do nothing, A0_STATE matches I2C device
+    U8G_PI_SCL		clock line (NOT USED)
+    U8G_PI_SDA		data line (NOT USED)
+    
+    U8G_PI_RESET		reset line (currently disabled, see below)
+
+  Protocol:
+    SLA, Cmd/Data Selection, Arguments
+    The command/data register is selected by a special instruction byte, which is sent after SLA
+    
+    The continue bit is always 0 so that a (re)start is equired for the change from cmd to/data mode
+*/
+
+#include "u8g.h"
+
+#if defined(U8G_RASPBERRY_PI)
+
+#include <wiringPi.h>
+#include <wiringPiI2C.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+
+#define I2C_SLA		0x3c
+#define I2C_CMD_MODE	0x000
+#define I2C_DATA_MODE	0x040
+
+#if defined(U8G_WITH_PINLIST)
+
+uint8_t u8g_com_raspberrypi_ssd_start_sequence(u8g_t *u8g)
+{
+  /* are we requested to set the a0 state? */
+  if ( u8g->pin_list[U8G_PI_SET_A0] == 0 )
+    return 1;	
+  
+  /* setup bus, might be a repeated start */
+  if ( u8g_i2c_start(I2C_SLA) == 0 )
+    return 0;
+  if ( u8g->pin_list[U8G_PI_A0_STATE] == 0 )
+  {
+    if ( u8g_i2c_send_mode(I2C_CMD_MODE) == 0 )
+      return 0;
+  }
+  else
+  {
+    if ( u8g_i2c_send_mode(I2C_DATA_MODE) == 0 )
+      return 0;
+  }
+  
+  
+  u8g->pin_list[U8G_PI_SET_A0] = 0;
+  return 1;
+}
+
+uint8_t u8g_com_raspberrypi_ssd_i2c_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr)
+{
+  switch(msg)
+  {
+    case U8G_COM_MSG_INIT:
+      u8g_i2c_init(u8g->pin_list[U8G_PI_I2C_OPTION]);
+      u8g_SetPIOutput(u8g, U8G_PI_RESET);
+      u8g_SetPIOutput(u8g, U8G_PI_A0);
+      break;
+    
+    case U8G_COM_MSG_STOP:
+      break;
+
+    case U8G_COM_MSG_RESET:
+      break;
+      
+    case U8G_COM_MSG_CHIP_SELECT:
+      u8g->pin_list[U8G_PI_A0_STATE] = 0;
+      u8g->pin_list[U8G_PI_SET_A0] = 1;		/* force a0 to set again, also forces start condition */
+      if ( arg_val == 0 )
+      {
+        /* disable chip, send stop condition */
+	u8g_i2c_stop();
+     }
+      else
+      {
+        /* enable, do nothing: any byte writing will trigger the i2c start */
+      }
+      break;
+
+    case U8G_COM_MSG_WRITE_BYTE:
+      //u8g->pin_list[U8G_PI_SET_A0] = 1;
+      if ( u8g_com_raspberrypi_ssd_start_sequence(u8g) == 0 )
+	return u8g_i2c_stop(), 0;
+      if ( u8g_i2c_send_byte(arg_val) == 0 )
+	return u8g_i2c_stop(), 0;
+      // u8g_i2c_stop();
+      break;
+    
+    case U8G_COM_MSG_WRITE_SEQ:
+      //u8g->pin_list[U8G_PI_SET_A0] = 1;
+      if ( u8g_com_raspberrypi_ssd_start_sequence(u8g) == 0 )
+	return u8g_i2c_stop(), 0;
+      {
+        register uint8_t *ptr = (uint8_t *)arg_ptr;
+        while( arg_val > 0 )
+        {
+	  if ( u8g_i2c_send_byte(*ptr++) == 0 )
+	    return u8g_i2c_stop(), 0;
+          arg_val--;
+        }
+      }
+      // u8g_i2c_stop();
+      break;
+
+    case U8G_COM_MSG_WRITE_SEQ_P:
+      //u8g->pin_list[U8G_PI_SET_A0] = 1;
+      if ( u8g_com_raspberrypi_ssd_start_sequence(u8g) == 0 )
+	return u8g_i2c_stop(), 0;
+      {
+        register uint8_t *ptr = (uint8_t *)arg_ptr;
+        while( arg_val > 0 )
+        {
+	  if ( u8g_i2c_send_byte(u8g_pgm_read(ptr)) == 0 )
+	    return 0;
+          ptr++;
+          arg_val--;
+        }
+      }
+      // u8g_i2c_stop();
+      break;
+      
+    case U8G_COM_MSG_ADDRESS:                     /* define cmd (arg_val = 0) or data mode (arg_val = 1) */
+      u8g->pin_list[U8G_PI_A0_STATE] = arg_val;
+      u8g->pin_list[U8G_PI_SET_A0] = 1;		/* force a0 to set again */
+    
+#ifdef OLD_CODE    
+      if ( i2c_state != 0 )
+      {
+	u8g_i2c_stop();
+	i2c_state = 0;
+      }
+
+      if ( u8g_com_raspberrypi_ssd_start_sequence(arg_val) == 0 )
+	return 0;
+    
+      /* setup bus, might be a repeated start */
+      /*
+      if ( u8g_i2c_start(I2C_SLA) == 0 )
+	return 0;
+      if ( arg_val == 0 )
+      {
+	i2c_state = 1;
+	
+	if ( u8g_i2c_send_byte(I2C_CMD_MODE) == 0 )
+	  return 0;
+      }
+      else
+      {
+	i2c_state = 2;
+	if ( u8g_i2c_send_byte(I2C_DATA_MODE) == 0 )
+	  return 0;
+      }
+      */
+#endif
+      break;
+  }
+  return 1;
+}
+
+#else	/* defined(U8G_WITH_PINLIST) */
+
+uint8_t u8g_com_raspberrypi_ssd_i2c_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr) {
+   return 1;
+}
+
+#endif	/* defined(U8G_WITH_PINLIST) */
+#endif
+