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_BLOCK_SHIFT 8
23 #define EE_DEVICE_SIZE ((uint32_t) 128 * (uint32_t) 1024)
25 /* Total bytes of available storage */
26 __xdata uint32_t ao_storage_total;
28 /* Block size - device is erased in these units. At least 256 bytes */
29 __xdata uint32_t ao_storage_block;
31 /* Byte offset of config block. Will be ao_storage_block bytes long */
32 __xdata uint32_t ao_storage_config;
34 /* Storage unit size - device reads and writes must be within blocks of this size. Usually 256 bytes. */
35 __xdata uint16_t ao_storage_unit;
38 * Using SPI on USART 0, with P1_2 as the chip select
44 static __xdata uint8_t ao_ee_mutex;
46 #define ao_ee_delay() do { \
52 static void ao_ee_cs_low(void)
59 static void ao_ee_cs_high(void)
66 struct ao_ee_instruction {
69 } __xdata ao_ee_instruction;
72 ao_ee_write_enable(void)
75 ao_ee_instruction.instruction = EE_WREN;
76 ao_spi_send(&ao_ee_instruction, 1);
84 ao_ee_instruction.instruction = EE_RDSR;
85 ao_spi_send(&ao_ee_instruction, 1);
86 ao_spi_recv(&ao_ee_instruction, 1);
88 return ao_ee_instruction.instruction;
92 ao_ee_wrsr(uint8_t status)
95 ao_ee_instruction.instruction = EE_WRSR;
96 ao_ee_instruction.address[0] = status;
97 ao_spi_send(&ao_ee_instruction, 2);
101 #define EE_BLOCK_NONE 0xffff
103 static __xdata uint8_t ao_ee_data[EE_BLOCK_SIZE];
104 static __pdata uint16_t ao_ee_block = EE_BLOCK_NONE;
105 static __pdata uint8_t ao_ee_block_dirty;
107 /* Write the current block to the EEPROM */
109 ao_ee_write_block(void)
113 status = ao_ee_rdsr();
114 if (status & (EE_STATUS_BP0|EE_STATUS_BP1|EE_STATUS_WPEN)) {
115 status &= ~(EE_STATUS_BP0|EE_STATUS_BP1|EE_STATUS_WPEN);
118 ao_ee_write_enable();
120 ao_ee_instruction.instruction = EE_WRITE;
121 ao_ee_instruction.address[0] = ao_ee_block >> 8;
122 ao_ee_instruction.address[1] = ao_ee_block;
123 ao_ee_instruction.address[2] = 0;
124 ao_spi_send(&ao_ee_instruction, 4);
125 ao_spi_send(ao_ee_data, EE_BLOCK_SIZE);
128 uint8_t status = ao_ee_rdsr();
129 if ((status & EE_STATUS_WIP) == 0)
134 /* Read the current block from the EEPROM */
136 ao_ee_read_block(void)
139 ao_ee_instruction.instruction = EE_READ;
140 ao_ee_instruction.address[0] = ao_ee_block >> 8;
141 ao_ee_instruction.address[1] = ao_ee_block;
142 ao_ee_instruction.address[2] = 0;
143 ao_spi_send(&ao_ee_instruction, 4);
144 ao_spi_recv(ao_ee_data, EE_BLOCK_SIZE);
149 ao_ee_flush_internal(void)
151 if (ao_ee_block_dirty) {
153 ao_ee_block_dirty = 0;
158 ao_ee_fill(uint16_t block)
160 if (block != ao_ee_block) {
161 ao_ee_flush_internal();
168 ao_storage_device_write(uint32_t pos, __xdata void *buf, uint16_t len) __reentrant
170 uint16_t block = (uint16_t) (pos >> EE_BLOCK_SHIFT);
172 /* Transfer the data */
173 ao_mutex_get(&ao_ee_mutex); {
174 if (len != EE_BLOCK_SIZE)
177 ao_ee_flush_internal();
180 memcpy(ao_ee_data + (uint16_t) (pos & 0xff), buf, len);
181 ao_ee_block_dirty = 1;
182 } ao_mutex_put(&ao_ee_mutex);
187 ao_storage_device_read(uint32_t pos, __xdata void *buf, uint16_t len) __reentrant
189 uint16_t block = (uint16_t) (pos >> EE_BLOCK_SHIFT);
191 /* Transfer the data */
192 ao_mutex_get(&ao_ee_mutex); {
194 memcpy(buf, ao_ee_data + (uint16_t) (pos & 0xff), len);
195 } ao_mutex_put(&ao_ee_mutex);
200 ao_storage_flush(void) __reentrant
202 ao_mutex_get(&ao_ee_mutex); {
203 ao_ee_flush_internal();
204 } ao_mutex_put(&ao_ee_mutex);
208 ao_storage_erase(uint32_t pos) __reentrant
210 ao_mutex_get(&ao_ee_mutex); {
211 ao_ee_flush_internal();
212 ao_ee_block = (uint16_t) (pos >> EE_BLOCK_SHIFT);
213 memset(ao_ee_data, 0xff, EE_BLOCK_SIZE);
214 ao_ee_block_dirty = 1;
215 } ao_mutex_put(&ao_ee_mutex);
220 ee_store(void) __reentrant
225 ao_storage_setup(void)
227 if (ao_storage_total == 0) {
228 ao_storage_total = EE_DEVICE_SIZE;
229 ao_storage_block = EE_BLOCK_SIZE;
230 ao_storage_config = EE_DEVICE_SIZE - EE_BLOCK_SIZE;
231 ao_storage_unit = EE_BLOCK_SIZE;
236 ao_storage_device_info(void) __reentrant
241 * To initialize the chip, set up the CS line and
245 ao_storage_device_init(void)
249 P1DIR |= (1 << EE_CS_INDEX);
250 P1SEL &= ~(1 << EE_CS_INDEX);