src: Add driver for AVR internal eeprom. Use for telepyro config.

[fw/altos] / src / avr / ao_eeprom_avr.c

diff --git a/src/avr/ao_eeprom_avr.c b/src/avr/ao_eeprom_avr.c
new file mode 100644 (file)
index 0000000..2451fa8
--- /dev/null
+++ b/src/avr/ao_eeprom_avr.c
@@ -0,0 +1,133 @@
+/*
+ * Copyright © 2012 Keith Packard <keithp@keithp.com>
+ * Copyright © 2011  Anthony Towns <aj@erisian.com.au>
+ *
+ * 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; version 2 of the License.
+ *
+ * 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.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include <ao.h>
+#include <ao_storage.h>
+
+/* Total bytes of available storage */
+__pdata ao_pos_t       ao_storage_total = 1024;
+
+/* Block size - device is erased in these units. */
+__pdata ao_pos_t       ao_storage_block = 1024;
+
+/* Byte offset of config block. Will be ao_storage_block bytes long */
+__pdata ao_pos_t       ao_storage_config = 0;
+
+/* Storage unit size - device reads and writes must be within blocks of this size. */
+__pdata uint16_t       ao_storage_unit = 1024;
+
+/*
+ * The internal flash chip is arranged in 8 byte sectors; the
+ * chip cannot erase in units smaller than that.
+ *
+ * Writing happens in units of 2 bytes and
+ * can only change bits from 1 to 0. So, you can rewrite
+ * the same contents, or append to an existing page easily enough
+ */
+
+/*
+ * Erase the specified sector
+ */
+uint8_t
+ao_storage_erase(ao_pos_t pos) __reentrant
+{
+       /* Not necessary */
+       return 1;
+}
+
+#define ao_intflash_wait_idle() do {                                   \
+               /* Wait for any outstanding writes to complete */       \
+               while (EECR & (1 << EEPE))                              \
+                       ;                                               \
+       } while (0)                                                     \
+
+static void
+ao_intflash_write(uint16_t pos, uint8_t d)
+{
+       ao_intflash_wait_idle();
+       EEAR = pos;
+       EEDR = d;
+       ao_arch_critical(
+               EECR |= (1 << EEMPE);
+               EECR |= (1 << EEPE);
+               );
+}
+
+static uint8_t
+ao_intflash_read(uint16_t pos)
+{
+       ao_intflash_wait_idle();
+       EEAR = pos;
+
+       EECR |= (1 << EERE);
+       return EEDR;
+}
+/*
+ * Write to flash
+ */
+
+uint8_t
+ao_storage_device_write(ao_pos_t pos32, __xdata void *v, uint16_t len) __reentrant
+{
+       uint16_t pos = pos32;
+       __xdata uint8_t *d = v;
+
+       if (pos >= ao_storage_total || pos + len > ao_storage_total)
+               return 0;
+
+       while (len--)
+               ao_intflash_write(pos++, *d++);
+
+       return 1;
+}
+
+/*
+ * Read from flash
+ */
+uint8_t
+ao_storage_device_read(ao_pos_t pos, __xdata void *v, uint16_t len) __reentrant
+{
+       uint8_t *d = v;
+       
+       if (pos >= ao_storage_total || pos + len > ao_storage_total)
+               return 0;
+       while (len--)
+               *d++ = ao_intflash_read(pos++);
+       return 1;
+}
+
+void
+ao_storage_flush(void) __reentrant
+{
+}
+
+void
+ao_storage_setup(void)
+{
+}
+
+void
+ao_storage_device_info(void) __reentrant
+{
+       printf ("Using internal flash\n");
+}
+
+void
+ao_storage_device_init(void)
+{
+}