2 * Copyright © 2009 Keith Packard <keithp@keithp.com>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; version 2 of the License.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
21 #define EE_BLOCK_SIZE ((uint16_t) (256))
22 #define EE_DEVICE_SIZE ((uint32_t) 128 * (uint32_t) 1024)
24 /* Total bytes of available storage */
25 __xdata uint32_t ao_storage_total;
27 /* Block size - device is erased in these units. At least 256 bytes */
28 __xdata uint32_t ao_storage_block;
30 /* Byte offset of config block. Will be ao_storage_block bytes long */
31 __xdata uint32_t ao_storage_config;
33 /* Storage unit size - device reads and writes must be within blocks of this size. Usually 256 bytes. */
34 __xdata uint16_t ao_storage_unit;
37 * Using SPI on USART 0, with P1_2 as the chip select
43 static __xdata uint8_t ao_ee_mutex;
45 #define ao_ee_delay() do { \
51 static void ao_ee_cs_low(void)
58 static void ao_ee_cs_high(void)
65 struct ao_ee_instruction {
68 } __xdata ao_ee_instruction;
71 ao_ee_write_enable(void)
74 ao_ee_instruction.instruction = EE_WREN;
75 ao_spi_send(&ao_ee_instruction, 1);
83 ao_ee_instruction.instruction = EE_RDSR;
84 ao_spi_send(&ao_ee_instruction, 1);
85 ao_spi_recv(&ao_ee_instruction, 1);
87 return ao_ee_instruction.instruction;
91 ao_ee_wrsr(uint8_t status)
94 ao_ee_instruction.instruction = EE_WRSR;
95 ao_ee_instruction.address[0] = status;
96 ao_spi_send(&ao_ee_instruction, 2);
100 #define EE_BLOCK_NONE 0xffff
102 static __xdata uint8_t ao_ee_data[EE_BLOCK_SIZE];
103 static __pdata uint16_t ao_ee_block = EE_BLOCK_NONE;
104 static __pdata uint8_t ao_ee_block_dirty;
106 /* Write the current block to the EEPROM */
108 ao_ee_write_block(void)
112 status = ao_ee_rdsr();
113 if (status & (EE_STATUS_BP0|EE_STATUS_BP1|EE_STATUS_WPEN)) {
114 status &= ~(EE_STATUS_BP0|EE_STATUS_BP1|EE_STATUS_WPEN);
117 ao_ee_write_enable();
119 ao_ee_instruction.instruction = EE_WRITE;
120 ao_ee_instruction.address[0] = ao_ee_block >> 8;
121 ao_ee_instruction.address[1] = ao_ee_block;
122 ao_ee_instruction.address[2] = 0;
123 ao_spi_send(&ao_ee_instruction, 4);
124 ao_spi_send(ao_ee_data, EE_BLOCK_SIZE);
127 uint8_t status = ao_ee_rdsr();
128 if ((status & EE_STATUS_WIP) == 0)
133 /* Read the current block from the EEPROM */
135 ao_ee_read_block(void)
138 ao_ee_instruction.instruction = EE_READ;
139 ao_ee_instruction.address[0] = ao_ee_block >> 8;
140 ao_ee_instruction.address[1] = ao_ee_block;
141 ao_ee_instruction.address[2] = 0;
142 ao_spi_send(&ao_ee_instruction, 4);
143 ao_spi_recv(ao_ee_data, EE_BLOCK_SIZE);
148 ao_ee_flush_internal(void)
150 if (ao_ee_block_dirty) {
152 ao_ee_block_dirty = 0;
157 ao_ee_fill(uint16_t block)
159 if (block != ao_ee_block) {
160 ao_ee_flush_internal();
167 ao_storage_device_write(uint32_t pos, __xdata void *buf, uint16_t len) __reentrant
169 uint16_t block = (uint16_t) (pos >> 8);
171 /* Transfer the data */
172 ao_mutex_get(&ao_ee_mutex); {
173 if (len != EE_BLOCK_SIZE)
176 ao_ee_flush_internal();
179 memcpy(ao_ee_data + (uint16_t) (pos & 0xff), buf, len);
180 ao_ee_block_dirty = 1;
181 } ao_mutex_put(&ao_ee_mutex);
186 ao_storage_device_read(uint32_t pos, __xdata void *buf, uint16_t len) __reentrant
188 uint16_t block = (uint16_t) (pos >> 8);
190 /* Transfer the data */
191 ao_mutex_get(&ao_ee_mutex); {
193 memcpy(buf, ao_ee_data + (uint16_t) (pos & 0xff), len);
194 } ao_mutex_put(&ao_ee_mutex);
199 ao_storage_flush(void) __reentrant
201 ao_mutex_get(&ao_ee_mutex); {
202 ao_ee_flush_internal();
203 } ao_mutex_put(&ao_ee_mutex);
207 ao_storage_erase(uint32_t pos) __reentrant
209 ao_mutex_get(&ao_ee_mutex); {
210 uint16_t block = (uint16_t) (pos >> 8);
212 memset(ao_ee_data, 0xff, EE_BLOCK_SIZE);
213 ao_ee_block_dirty = 1;
214 } ao_mutex_put(&ao_ee_mutex);
219 ee_store(void) __reentrant
224 ao_storage_setup(void)
226 if (ao_storage_total == 0) {
227 ao_storage_total = EE_DEVICE_SIZE;
228 ao_storage_block = EE_BLOCK_SIZE;
229 ao_storage_config = EE_DEVICE_SIZE - EE_BLOCK_SIZE;
230 ao_storage_unit = EE_BLOCK_SIZE;
235 ao_storage_device_info(void) __reentrant
240 * To initialize the chip, set up the CS line and
244 ao_storage_device_init(void)
248 P1DIR |= (1 << EE_CS_INDEX);
249 P1SEL &= ~(1 << EE_CS_INDEX);