+/**
+ * \file
+ * <!--
+ * This file is part of BeRTOS.
+ *
+ * Bertos 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 St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * As a special exception, you may use this file as part of a free software
+ * library without restriction. Specifically, if other files instantiate
+ * templates or use macros or inline functions from this file, or you compile
+ * this file and link it with other files to produce an executable, this
+ * file does not by itself cause the resulting executable to be covered by
+ * the GNU General Public License. This exception does not however
+ * invalidate any other reasons why the executable file might be covered by
+ * the GNU General Public License.
+ *
+ * Copyright 2003, 2004, 2005 Develer S.r.l. (http://www.develer.com/)
+ *
+ * -->
+ *
+ * \brief Driver for the 24xx16 and 24xx256 I2C EEPROMS (implementation)
+ *
+ * \note This implementation is AVR specific.
+ *
+ * \version $Id$
+ * \author Stefano Fedrigo <aleph@develer.com>
+ * \author Bernardo Innocenti <bernie@develer.com>
+ */
+
+#include "eeprom.h"
+
+#include <cfg/debug.h>
+#include <appconfig.h> // CONFIG_EEPROM_VERIFY
+#include <cfg/macros.h> // MIN()
+#include <cpu/attr.h>
+#include CPU_HEADER(twi)
+#include <drv/wdt.h>
+#include <mware/byteorder.h> // cpu_to_be16()
+
+#include <string.h> // memset()
+
+
+// Configuration sanity checks
+#if !defined(CONFIG_EEPROM_VERIFY) || (CONFIG_EEPROM_VERIFY != 0 && CONFIG_EEPROM_VERIFY != 1)
+ #error CONFIG_EEPROM_VERIFY must be defined to either 0 or 1
+#endif
+
+/**
+ * EEPROM ID code
+ */
+#define EEPROM_ID 0xA0
+
+/**
+ * This macros form the correct slave address for EEPROMs
+ */
+#define EEPROM_ADDR(x) (EEPROM_ID | (((uint8_t)(x)) << 1))
+
+
+
+
+/**
+ * Copy \c count bytes from buffer \c buf to
+ * eeprom at address \c addr.
+ */
+static bool eeprom_writeRaw(e2addr_t addr, const void *buf, size_t count)
+{
+ bool result = true;
+ ASSERT(addr + count <= EEPROM_SIZE);
+
+ while (count && result)
+ {
+ /*
+ * Split write in multiple sequential mode operations that
+ * don't cross page boundaries.
+ */
+ size_t size =
+ MIN(count, (size_t)(EEPROM_BLKSIZE - (addr & (EEPROM_BLKSIZE - 1))));
+
+ #if CONFIG_EEPROM_TYPE == EEPROM_24XX16
+ /*
+ * The 24LC16 uses the slave address as a 3-bit
+ * block address.
+ */
+ uint8_t blk_addr = (uint8_t)((addr >> 8) & 0x07);
+ uint8_t blk_offs = (uint8_t)addr;
+
+ result =
+ twi_start_w(EEPROM_ADDR(blk_addr))
+ && twi_send(&blk_offs, sizeof blk_offs)
+ && twi_send(buf, size);
+
+ #elif CONFIG_EEPROM_TYPE == EEPROM_24XX256
+
+ // 24LC256 wants big-endian addresses
+ uint16_t addr_be = cpu_to_be16(addr);
+
+ result =
+ twi_start_w(EEPROM_ID)
+ && twi_send((uint8_t *)&addr_be, sizeof addr_be)
+ && twi_send(buf, size);
+
+ #else
+ #error Unknown device type
+ #endif
+
+ twi_stop();
+
+ // DEBUG
+ //kprintf("addr=%d, count=%d, size=%d, *#?=%d\n",
+ // addr, count, size,
+ // (EEPROM_BLKSIZE - (addr & (EEPROM_BLKSIZE - 1)))
+ //);
+
+ /* Update count and addr for next operation */
+ count -= size;
+ addr += size;
+ buf = ((const char *)buf) + size;
+ }
+
+ if (!result)
+ TRACEMSG("Write error!");
+ return result;
+}
+
+
+#if CONFIG_EEPROM_VERIFY
+/**
+ * Check that the contents of an EEPROM range
+ * match with a provided data buffer.
+ *
+ * \return true on success.
+ */
+static bool eeprom_verify(e2addr_t addr, const void *buf, size_t count)
+{
+ uint8_t verify_buf[16];
+ bool result = true;
+
+ while (count && result)
+ {
+ /* Split read in smaller pieces */
+ size_t size = MIN(count, sizeof verify_buf);
+
+ /* Read back buffer */
+ if (eeprom_read(addr, verify_buf, size))
+ {
+ if (memcmp(buf, verify_buf, size) != 0)
+ {
+ TRACEMSG("Data mismatch!");
+ result = false;
+ }
+ }
+ else
+ {
+ TRACEMSG("Read error!");
+ result = false;
+ }
+
+ /* Update count and addr for next operation */
+ count -= size;
+ addr += size;
+ buf = ((const char *)buf) + size;
+ }
+
+ return result;
+}
+#endif /* CONFIG_EEPROM_VERIFY */
+
+
+bool eeprom_write(e2addr_t addr, const void *buf, size_t count)
+{
+#if CONFIG_EEPROM_VERIFY
+ int retries = 5;
+
+ while (retries--)
+ if (eeprom_writeRaw(addr, buf, count)
+ && eeprom_verify(addr, buf, count))
+ return true;
+
+ return false;
+
+#else /* !CONFIG_EEPROM_VERIFY */
+ return eeprom_writeRaw(addr, buf, count);
+#endif /* !CONFIG_EEPROM_VERIFY */
+}
+
+
+/**
+ * Copy \c count bytes at address \c addr
+ * from eeprom to RAM to buffer \c buf.
+ *
+ * \return true on success.
+ */
+bool eeprom_read(e2addr_t addr, void *buf, size_t count)
+{
+ ASSERT(addr + count <= EEPROM_SIZE);
+
+#if CONFIG_EEPROM_TYPE == EEPROM_24XX16
+ /*
+ * The 24LC16 uses the slave address as a 3-bit
+ * block address.
+ */
+ uint8_t blk_addr = (uint8_t)((addr >> 8) & 0x07);
+ uint8_t blk_offs = (uint8_t)addr;
+
+ bool res =
+ twi_start_w(EEPROM_ADDR(blk_addr))
+ && twi_send(&blk_offs, sizeof blk_offs)
+ && twi_start_r(EEPROM_ADDR(blk_addr))
+ && twi_recv(buf, count);
+
+#elif CONFIG_EEPROM_TYPE == EEPROM_24XX256
+
+ // 24LC256 wants big-endian addresses
+ addr = cpu_to_be16(addr);
+
+ bool res =
+ twi_start_w(EEPROM_ID)
+ && twi_send((uint8_t *)&addr, sizeof(addr))
+ && twi_start_r(EEPROM_ID)
+ && twi_recv(buf, count);
+#else
+ #error Unknown device type
+#endif
+
+ twi_stop();
+
+ if (!res)
+ TRACEMSG("Read error!");
+ return res;
+}
+
+
+/**
+ * Write a single character \a c at address \a addr.
+ */
+bool eeprom_write_char(e2addr_t addr, char c)
+{
+ return eeprom_write(addr, &c, 1);
+}
+
+
+/**
+ * Read a single character at address \a addr.
+ *
+ * \return the requested character or -1 in case of failure.
+ */
+int eeprom_read_char(e2addr_t addr)
+{
+ char c;
+
+ if (eeprom_read(addr, &c, 1))
+ return c;
+ else
+ return -1;
+}
+
+
+/**
+ * Erase specified part of eeprom, writing 0xFF.
+ *
+ * \param addr starting address
+ * \param count length of block to erase
+ */
+void eeprom_erase(e2addr_t addr, size_t count)
+{
+ uint8_t buf[EEPROM_BLKSIZE];
+ memset(buf, 0xFF, sizeof buf);
+
+ // Clear all but struct hw_info at start of eeprom
+ while (count)
+ {
+ // Long operation, reset watchdog
+ wdt_reset();
+
+ size_t size = MIN(count, sizeof buf);
+ eeprom_write(addr, buf, size);
+ addr += size;
+ count -= size;
+ }
+}
+
+
+/**
+ * Initialize TWI module.
+ */
+void eeprom_init(void)
+{
+ twi_init();
+}
+
+
+#ifdef _DEBUG
+
+#include <string.h>
+
+void eeprom_test(void)
+{
+ static const char magic[14] = "Humpty Dumpty";
+ char buf[sizeof magic];
+ size_t i;
+
+ // Write something to EEPROM using unaligned sequential writes
+ for (i = 0; i < 42; ++i)
+ {
+ wdt_reset();
+ eeprom_write(i * sizeof magic, magic, sizeof magic);
+ }
+
+ // Read back with single-byte reads
+ for (i = 0; i < 42 * sizeof magic; ++i)
+ {
+ wdt_reset();
+ eeprom_read(i, buf, 1);
+ kprintf("EEPROM byte read: %c (%d)\n", buf[0], buf[0]);
+ ASSERT(buf[0] == magic[i % sizeof magic]);
+ }
+
+ // Read back again using sequential reads
+ for (i = 0; i < 42; ++i)
+ {
+ wdt_reset();
+ memset(buf, 0, sizeof buf);
+ eeprom_read(i * sizeof magic, buf, sizeof magic);
+ kprintf("EEPROM seq read @ 0x%x: '%s'\n", i * sizeof magic, buf);
+ ASSERT(memcmp(buf, magic, sizeof magic) == 0);
+ }
+}
+
+#endif // _DEBUG