Diff: u8g_state.c

Revision:

0:972874f31c98

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/u8g_state.c	Wed Mar 07 12:49:14 2018 +0000
@@ -0,0 +1,151 @@
+/*
+
+  u8g_state.c
+  
+  backup and restore hardware state
+
+  Universal 8bit Graphics Library
+  
+  Copyright (c) 2011, olikraus@gmail.com
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without modification, 
+  are permitted provided that the following conditions are met:
+
+  * Redistributions of source code must retain the above copyright notice, this list 
+    of conditions and the following disclaimer.
+    
+  * Redistributions in binary form must reproduce the above copyright notice, this 
+    list of conditions and the following disclaimer in the documentation and/or other 
+    materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 
+  CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 
+  INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
+  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 
+  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
+  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 
+  NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
+  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 
+  STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
+  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 
+  ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.  
+  
+
+  state callback: backup env U8G_STATE_MSG_BACKUP_ENV
+  device callback: DEV_MSG_INIT
+  state callback: backup u8g U8G_STATE_MSG_BACKUP_U8G
+  state callback: restore env U8G_STATE_MSG_RESTORE_ENV
+
+  state callback: backup env U8G_STATE_MSG_BACKUP_ENV
+  state callback: retore u8g U8G_STATE_MSG_RESTORE_U8G
+  DEV_MSG_PAGE_FIRST or DEV_MSG_PAGE_NEXT
+  state callback: restore env U8G_STATE_MSG_RESTORE_ENV
+
+*/
+
+#include <stddef.h>
+#include "u8g.h"
+
+void u8g_state_dummy_cb(uint8_t msg)
+{
+  /* the dummy procedure does nothing */
+}
+
+void u8g_SetHardwareBackup(u8g_t *u8g, u8g_state_cb backup_cb)
+{
+  u8g->state_cb = backup_cb;
+  /* in most cases the init message was already sent, so this will backup the */
+  /* current u8g state */
+  backup_cb(U8G_STATE_MSG_BACKUP_U8G);
+}
+
+
+/*===============================================================*/
+/* register variable for restoring interrupt state */
+
+#if defined(__AVR__)
+uint8_t global_SREG_backup;
+#endif
+
+
+
+/*===============================================================*/
+/* AVR */
+
+#if defined(__AVR__)
+#define U8G_ATMEGA_HW_SPI
+
+/* remove the definition for attiny */
+#if __AVR_ARCH__ == 2
+#undef U8G_ATMEGA_HW_SPI
+#endif
+#if __AVR_ARCH__ == 25
+#undef U8G_ATMEGA_HW_SPI
+#endif
+#endif
+
+#if defined(U8G_ATMEGA_HW_SPI)
+#include <avr/interrupt.h>
+static uint8_t u8g_state_avr_spi_memory[2];
+
+void u8g_backup_spi(uint8_t msg)
+{
+  if ( U8G_STATE_MSG_IS_BACKUP(msg) )
+  {
+    u8g_state_avr_spi_memory[U8G_STATE_MSG_GET_IDX(msg)] = SPCR;
+  }
+  else
+  {
+    uint8_t tmp = SREG;
+    cli();
+    SPCR = 0;
+    SPCR = u8g_state_avr_spi_memory[U8G_STATE_MSG_GET_IDX(msg)];
+    SREG = tmp;
+  }
+}
+
+#elif defined(ARDUINO) && defined(__arm__)		// Arduino Due, maybe we should better check for __SAM3X8E__
+
+#include "sam.h"
+
+struct sam_backup_struct
+{
+  uint32_t mr;
+  uint32_t sr;
+  uint32_t csr[4];  
+} sam_backup[2];
+
+void u8g_backup_spi(uint8_t msg)
+{
+  uint8_t idx = U8G_STATE_MSG_GET_IDX(msg);
+  if ( U8G_STATE_MSG_IS_BACKUP(msg) )
+  {
+    sam_backup[idx].mr = SPI0->SPI_MR;
+    sam_backup[idx].sr = SPI0->SPI_SR;
+    sam_backup[idx].csr[0] = SPI0->SPI_CSR[0];
+    sam_backup[idx].csr[1] = SPI0->SPI_CSR[1];
+    sam_backup[idx].csr[2] = SPI0->SPI_CSR[2];
+    sam_backup[idx].csr[3] = SPI0->SPI_CSR[3];
+  }
+  else
+  {
+    SPI0->SPI_MR = sam_backup[idx].mr;
+    SPI0->SPI_CSR[0] = sam_backup[idx].csr[0];
+    SPI0->SPI_CSR[1] = sam_backup[idx].csr[1];
+    SPI0->SPI_CSR[2] = sam_backup[idx].csr[2];
+    SPI0->SPI_CSR[3] = sam_backup[idx].csr[3];
+  }
+}
+
+#else
+
+void u8g_backup_spi(uint8_t msg)
+{
+}
+
+#endif
+
+