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/*
* Copyright © 2009 Keith Packard <keithp@keithp.com>
*
* 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_25lc1024.h"
#define EE_BLOCK_SIZE ((uint16_t) (256))
#define EE_BLOCK_SHIFT 8
#define EE_DEVICE_SIZE ((uint32_t) 128 * (uint32_t) 1024)
/* Total bytes of available storage */
__pdata uint32_t ao_storage_total;
/* Block size - device is erased in these units. At least 256 bytes */
__pdata uint32_t ao_storage_block;
/* Byte offset of config block. Will be ao_storage_block bytes long */
__pdata uint32_t ao_storage_config;
/* Storage unit size - device reads and writes must be within blocks of this size. Usually 256 bytes. */
__pdata uint16_t ao_storage_unit;
/*
* Using SPI on USART 0, with P1_2 as the chip select
*/
#define EE_CS P1_2
#define EE_CS_INDEX 2
static __xdata uint8_t ao_ee_mutex;
#define ao_ee_delay() do { \
_asm nop _endasm; \
_asm nop _endasm; \
_asm nop _endasm; \
} while(0)
#define ao_ee_cs_low() ao_spi_get_bit(EE_CS)
#define ao_ee_cs_high() ao_spi_put_bit(EE_CS)
struct ao_ee_instruction {
uint8_t instruction;
uint8_t address[3];
} __xdata ao_ee_instruction;
static void
ao_ee_write_enable(void)
{
ao_ee_cs_low();
ao_ee_instruction.instruction = EE_WREN;
ao_spi_send(&ao_ee_instruction, 1);
ao_ee_cs_high();
}
static uint8_t
ao_ee_rdsr(void)
{
ao_ee_cs_low();
ao_ee_instruction.instruction = EE_RDSR;
ao_spi_send(&ao_ee_instruction, 1);
ao_spi_recv(&ao_ee_instruction, 1);
ao_ee_cs_high();
return ao_ee_instruction.instruction;
}
static void
ao_ee_wrsr(uint8_t status)
{
ao_ee_cs_low();
ao_ee_instruction.instruction = EE_WRSR;
ao_ee_instruction.address[0] = status;
ao_spi_send(&ao_ee_instruction, 2);
ao_ee_cs_high();
}
#define EE_BLOCK_NONE 0xffff
static __xdata uint8_t ao_ee_data[EE_BLOCK_SIZE];
static __pdata uint16_t ao_ee_block = EE_BLOCK_NONE;
static __pdata uint8_t ao_ee_block_dirty;
/* Write the current block to the EEPROM */
static void
ao_ee_write_block(void)
{
uint8_t status;
status = ao_ee_rdsr();
if (status & (EE_STATUS_BP0|EE_STATUS_BP1|EE_STATUS_WPEN)) {
status &= ~(EE_STATUS_BP0|EE_STATUS_BP1|EE_STATUS_WPEN);
ao_ee_wrsr(status);
}
ao_ee_write_enable();
ao_ee_cs_low();
ao_ee_instruction.instruction = EE_WRITE;
ao_ee_instruction.address[0] = ao_ee_block >> 8;
ao_ee_instruction.address[1] = ao_ee_block;
ao_ee_instruction.address[2] = 0;
ao_spi_send(&ao_ee_instruction, 4);
ao_spi_send(ao_ee_data, EE_BLOCK_SIZE);
ao_ee_cs_high();
for (;;) {
uint8_t status = ao_ee_rdsr();
if ((status & EE_STATUS_WIP) == 0)
break;
}
}
/* Read the current block from the EEPROM */
static void
ao_ee_read_block(void)
{
ao_ee_cs_low();
ao_ee_instruction.instruction = EE_READ;
ao_ee_instruction.address[0] = ao_ee_block >> 8;
ao_ee_instruction.address[1] = ao_ee_block;
ao_ee_instruction.address[2] = 0;
ao_spi_send(&ao_ee_instruction, 4);
ao_spi_recv(ao_ee_data, EE_BLOCK_SIZE);
ao_ee_cs_high();
}
static void
ao_ee_flush_internal(void)
{
if (ao_ee_block_dirty) {
ao_ee_write_block();
ao_ee_block_dirty = 0;
}
}
static void
ao_ee_fill(uint16_t block)
{
if (block != ao_ee_block) {
ao_ee_flush_internal();
ao_ee_block = block;
ao_ee_read_block();
}
}
uint8_t
ao_storage_device_write(uint32_t pos, __xdata void *buf, uint16_t len) __reentrant
{
uint16_t block = (uint16_t) (pos >> EE_BLOCK_SHIFT);
/* Transfer the data */
ao_mutex_get(&ao_ee_mutex); {
if (len != EE_BLOCK_SIZE)
ao_ee_fill(block);
else {
ao_ee_flush_internal();
ao_ee_block = block;
}
memcpy(ao_ee_data + (uint16_t) (pos & 0xff), buf, len);
ao_ee_block_dirty = 1;
} ao_mutex_put(&ao_ee_mutex);
return 1;
}
uint8_t
ao_storage_device_read(uint32_t pos, __xdata void *buf, uint16_t len) __reentrant
{
uint16_t block = (uint16_t) (pos >> EE_BLOCK_SHIFT);
/* Transfer the data */
ao_mutex_get(&ao_ee_mutex); {
ao_ee_fill(block);
memcpy(buf, ao_ee_data + (uint16_t) (pos & 0xff), len);
} ao_mutex_put(&ao_ee_mutex);
return 1;
}
void
ao_storage_flush(void) __reentrant
{
ao_mutex_get(&ao_ee_mutex); {
ao_ee_flush_internal();
} ao_mutex_put(&ao_ee_mutex);
}
uint8_t
ao_storage_erase(uint32_t pos) __reentrant
{
ao_mutex_get(&ao_ee_mutex); {
ao_ee_flush_internal();
ao_ee_block = (uint16_t) (pos >> EE_BLOCK_SHIFT);
memset(ao_ee_data, 0xff, EE_BLOCK_SIZE);
ao_ee_block_dirty = 1;
} ao_mutex_put(&ao_ee_mutex);
return 1;
}
static void
ee_store(void) __reentrant
{
}
void
ao_storage_setup(void)
{
if (ao_storage_total == 0) {
ao_storage_total = EE_DEVICE_SIZE;
ao_storage_block = EE_BLOCK_SIZE;
ao_storage_config = EE_DEVICE_SIZE - EE_BLOCK_SIZE;
ao_storage_unit = EE_BLOCK_SIZE;
}
}
void
ao_storage_device_info(void) __reentrant
{
}
/*
* To initialize the chip, set up the CS line and
* the SPI interface
*/
void
ao_storage_device_init(void)
{
/* set up CS */
EE_CS = 1;
P1DIR |= (1 << EE_CS_INDEX);
P1SEL &= ~(1 << EE_CS_INDEX);
}
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