2 * Copyright © 2012 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.
19 #include <ao_mma655x.h>
27 #define PRINTD(l, ...) do { if (DEBUG & (l)) { printf ("\r%5u %s: ", ao_tick_count, __func__); printf(__VA_ARGS__); flush(); } } while(0)
32 uint8_t ao_mma655x_spi_index = AO_MMA655X_SPI_INDEX;
35 ao_mma655x_start(void) {
36 ao_spi_get_bit(AO_MMA655X_CS_PORT,
44 ao_mma655x_stop(void) {
45 ao_spi_put_bit(AO_MMA655X_CS_PORT,
48 AO_MMA655X_SPI_INDEX);
52 ao_mma655x_restart(void) {
54 ao_gpio_set(AO_MMA655X_CS_PORT, AO_MMA655X_CS_PIN, AO_MMA655X_CS, 1);
56 /* Emperical testing on STM32L151 at 32MHz for this delay amount */
57 for (i = 0; i < 10; i++)
59 ao_gpio_set(AO_MMA655X_CS_PORT, AO_MMA655X_CS_PIN, AO_MMA655X_CS, 0);
66 /* down to four bits */
67 p = (v ^ (v >> 4)) & 0xf;
69 /* Cute lookup hack -- 0x6996 encodes the sixteen
70 * even parity values in order.
72 p = (~0x6996 >> p) & 1;
78 ao_mma655x_cmd(uint8_t d[2])
81 PRINTD(DEBUG_LOW, "\tSEND %02x %02x\n", d[0], d[1]);
82 ao_spi_duplex(d, d, 2, AO_MMA655X_SPI_INDEX);
83 PRINTD(DEBUG_LOW, "\t\tRECV %02x %02x\n", d[0], d[1]);
89 ao_mma655x_reg_read(uint8_t addr)
93 d[0] = addr | (ao_parity(addr) << 7);
95 ao_spi_send(&d, 2, AO_MMA655X_SPI_INDEX);
98 /* Send a dummy read of 00 to clock out the SPI data */
101 ao_spi_duplex(&d, &d, 2, AO_MMA655X_SPI_INDEX);
103 PRINTD(DEBUG_LOW, "read %x = %x %x\n", addr, d[0], d[1]);
108 ao_mma655x_reg_write(uint8_t addr, uint8_t value)
112 PRINTD(DEBUG_LOW, "write %x %x\n", addr, value);
113 addr |= (1 << 6); /* write mode */
114 d[0] = addr | (ao_parity(addr^value) << 7);
117 ao_spi_send(d, 2, AO_MMA655X_SPI_INDEX);
124 ao_mma655x_value(void)
129 d[0] = ((0 << 6) | /* Axis selection (X) */
130 (1 << 5) | /* Acceleration operation */
131 (1 << 4)); /* Raw data */
132 d[1] = ((1 << 3) | /* must be one */
133 (1 << 2) | /* Unsigned data */
134 (0 << 1) | /* Arm disabled */
135 (1 << 0)); /* Odd parity */
137 PRINTD(DEBUG_LOW, "value SEND %02x %02x\n", d[0], d[1]);
138 ao_spi_send(d, 2, AO_MMA655X_SPI_INDEX);
139 ao_mma655x_restart();
142 ao_spi_duplex(d, d, 2, AO_MMA655X_SPI_INDEX);
144 PRINTD(DEBUG_LOW, "value RECV %02x %02x\n", d[0], d[1]);
146 v = (uint16_t) d[1] << 2;
148 v |= (uint16_t) (d[0] & 3) << 10;
153 ao_mma655x_reset(void) {
154 PRINTD(DEBUG_HIGH, "reset\n");
155 ao_mma655x_reg_write(AO_MMA655X_DEVCTL,
156 (0 << AO_MMA655X_DEVCTL_RES_1) |
157 (0 << AO_MMA655X_DEVCTL_RES_0));
158 ao_mma655x_reg_write(AO_MMA655X_DEVCTL,
159 (1 << AO_MMA655X_DEVCTL_RES_1) |
160 (1 << AO_MMA655X_DEVCTL_RES_0));
161 ao_mma655x_reg_write(AO_MMA655X_DEVCTL,
162 (0 << AO_MMA655X_DEVCTL_RES_1) |
163 (1 << AO_MMA655X_DEVCTL_RES_0));
166 #define DEVCFG_VALUE (\
167 (1 << AO_MMA655X_DEVCFG_OC) | /* Disable offset cancelation */ \
168 (1 << AO_MMA655X_DEVCFG_SD) | /* Receive unsigned data */ \
169 (0 << AO_MMA655X_DEVCFG_OFMON) | /* Disable offset monitor */ \
170 (AO_MMA655X_DEVCFG_A_CFG_DISABLE << AO_MMA655X_DEVCFG_A_CFG))
172 #define AXISCFG_VALUE (\
173 (0 << AO_MMA655X_AXISCFG_LPF)) /* 100Hz 4-pole filter */
176 #define AO_ST_TRIES 10
177 #define AO_ST_DELAY AO_MS_TO_TICKS(100)
180 ao_mma655x_setup(void)
187 uint8_t s0, s1, s2, s3;
191 for (tries = 0; tries < AO_ST_TRIES; tries++) {
192 ao_delay(AO_MS_TO_TICKS(10));
194 ao_delay(AO_MS_TO_TICKS(10));
196 devstat = ao_mma655x_reg_read(AO_MMA655X_DEVSTAT);
197 PRINTD(DEBUG_HIGH, "devstat %x\n", devstat);
199 if (!(devstat & (1 << AO_MMA655X_DEVSTAT_DEVRES)))
202 /* Configure R/W register values.
203 * Most of them relate to the arming feature, which
204 * we don't use, so the only registers we need to
205 * write are DEVCFG and AXISCFG
208 ao_mma655x_reg_write(AO_MMA655X_DEVCFG,
209 DEVCFG_VALUE | (0 << AO_MMA655X_DEVCFG_ENDINIT));
214 ao_mma655x_reg_write(AO_MMA655X_AXISCFG,
216 (1 << AO_MMA655X_AXISCFG_ST));
217 ao_delay(AO_MS_TO_TICKS(10));
219 a_st = ao_mma655x_value();
221 ao_mma655x_reg_write(AO_MMA655X_AXISCFG,
223 (0 << AO_MMA655X_AXISCFG_ST));
225 ao_delay(AO_MS_TO_TICKS(10));
227 a = ao_mma655x_value();
229 st_change = a_st - a;
231 PRINTD(DEBUG_HIGH, "self test %d normal %d change %d\n", a_st, a, st_change);
233 if (AO_ST_MIN <= st_change && st_change <= AO_ST_MAX)
235 ao_delay(AO_ST_DELAY);
237 if (tries == AO_ST_TRIES)
238 ao_sensor_errors = 1;
240 ao_mma655x_reg_write(AO_MMA655X_DEVCFG,
241 DEVCFG_VALUE | (1 << AO_MMA655X_DEVCFG_ENDINIT));
243 s0 = ao_mma655x_reg_read(AO_MMA655X_SN0);
244 s1 = ao_mma655x_reg_read(AO_MMA655X_SN1);
245 s2 = ao_mma655x_reg_read(AO_MMA655X_SN2);
246 s3 = ao_mma655x_reg_read(AO_MMA655X_SN3);
247 lot = ((uint32_t) s3 << 24) | ((uint32_t) s2 << 16) |
248 ((uint32_t) s1 << 8) | ((uint32_t) s0);
249 serial = lot & 0x1fff;
251 pn = ao_mma655x_reg_read(AO_MMA655X_PN);
255 uint16_t ao_mma655x_current;
258 ao_mma655x_dump(void)
260 printf ("MMA655X value %d\n", ao_mma655x_current);
263 __code struct ao_cmds ao_mma655x_cmds[] = {
264 { ao_mma655x_dump, "A\0Display MMA655X data" },
273 ao_mma655x_current = ao_mma655x_value();
275 AO_DATA_PRESENT(AO_DATA_MMA655X);
281 static __xdata struct ao_task ao_mma655x_task;
284 ao_mma655x_init(void)
286 ao_cmd_register(&ao_mma655x_cmds[0]);
287 ao_spi_init_cs(AO_MMA655X_CS_PORT, (1 << AO_MMA655X_CS_PIN));
289 ao_add_task(&ao_mma655x_task, ao_mma655x, "mma655x");