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; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
20 #include <ao_mma655x.h>
28 #define PRINTD(l, ...) do { if (DEBUG & (l)) { printf ("\r%5u %s: ", ao_tick_count, __func__); printf(__VA_ARGS__); flush(); } } while(0)
34 ao_mma655x_start(void) {
35 ao_spi_get_bit(AO_MMA655X_CS_PORT,
42 ao_mma655x_stop(void) {
43 ao_spi_put_bit(AO_MMA655X_CS_PORT,
45 AO_MMA655X_SPI_INDEX);
49 ao_mma655x_restart(void) {
51 ao_gpio_set(AO_MMA655X_CS_PORT, AO_MMA655X_CS_PIN, 1);
53 /* Emperical testing on STM32L151 at 32MHz for this delay amount */
54 for (i = 0; i < 10; i++)
56 ao_gpio_set(AO_MMA655X_CS_PORT, AO_MMA655X_CS_PIN, 0);
63 /* down to four bits */
64 p = (v ^ (v >> 4)) & 0xf;
66 /* Cute lookup hack -- 0x6996 encodes the sixteen
67 * even parity values in order.
69 p = (~0x6996 >> p) & 1;
75 ao_mma655x_cmd(uint8_t d[2])
78 PRINTD(DEBUG_LOW, "\tSEND %02x %02x\n", d[0], d[1]);
79 ao_spi_duplex(d, d, 2, AO_MMA655X_SPI_INDEX);
80 PRINTD(DEBUG_LOW, "\t\tRECV %02x %02x\n", d[0], d[1]);
86 ao_mma655x_reg_read(uint8_t addr)
90 d[0] = addr | (ao_parity(addr) << 7);
92 ao_spi_send(&d, 2, AO_MMA655X_SPI_INDEX);
95 /* Send a dummy read of 00 to clock out the SPI data */
98 ao_spi_duplex(&d, &d, 2, AO_MMA655X_SPI_INDEX);
100 PRINTD(DEBUG_LOW, "read %x = %x %x\n", addr, d[0], d[1]);
105 ao_mma655x_reg_write(uint8_t addr, uint8_t value)
109 PRINTD(DEBUG_LOW, "write %x %x\n", addr, value);
110 addr |= (1 << 6); /* write mode */
111 d[0] = addr | (ao_parity(addr^value) << 7);
114 ao_spi_send(d, 2, AO_MMA655X_SPI_INDEX);
121 ao_mma655x_value(void)
126 d[0] = ((0 << 6) | /* Axis selection (X) */
127 (1 << 5) | /* Acceleration operation */
128 (1 << 4)); /* Raw data */
129 d[1] = ((1 << 3) | /* must be one */
130 (1 << 2) | /* Unsigned data */
131 (0 << 1) | /* Arm disabled */
132 (1 << 0)); /* Odd parity */
134 PRINTD(DEBUG_LOW, "value SEND %02x %02x\n", d[0], d[1]);
135 ao_spi_send(d, 2, AO_MMA655X_SPI_INDEX);
136 ao_mma655x_restart();
139 ao_spi_duplex(d, d, 2, AO_MMA655X_SPI_INDEX);
141 PRINTD(DEBUG_LOW, "value RECV %02x %02x\n", d[0], d[1]);
143 v = (uint16_t) d[1] << 2;
145 v |= (uint16_t) (d[0] & 3) << 10;
150 ao_mma655x_reset(void) {
151 PRINTD(DEBUG_HIGH, "reset\n");
152 ao_mma655x_reg_write(AO_MMA655X_DEVCTL,
153 (0 << AO_MMA655X_DEVCTL_RES_1) |
154 (0 << AO_MMA655X_DEVCTL_RES_0));
155 ao_mma655x_reg_write(AO_MMA655X_DEVCTL,
156 (1 << AO_MMA655X_DEVCTL_RES_1) |
157 (1 << AO_MMA655X_DEVCTL_RES_0));
158 ao_mma655x_reg_write(AO_MMA655X_DEVCTL,
159 (0 << AO_MMA655X_DEVCTL_RES_1) |
160 (1 << AO_MMA655X_DEVCTL_RES_0));
163 #define DEVCFG_VALUE (\
164 (1 << AO_MMA655X_DEVCFG_OC) | /* Disable offset cancelation */ \
165 (1 << AO_MMA655X_DEVCFG_SD) | /* Receive unsigned data */ \
166 (0 << AO_MMA655X_DEVCFG_OFMON) | /* Disable offset monitor */ \
167 (AO_MMA655X_DEVCFG_A_CFG_DISABLE << AO_MMA655X_DEVCFG_A_CFG))
169 #define AXISCFG_VALUE (\
170 (0 << AO_MMA655X_AXISCFG_LPF)) /* 100Hz 4-pole filter */
173 #define AO_ST_TRIES 10
174 #define AO_ST_DELAY AO_MS_TO_TICKS(100)
177 ao_mma655x_setup(void)
184 uint8_t s0, s1, s2, s3;
188 for (tries = 0; tries < AO_ST_TRIES; tries++) {
189 ao_delay(AO_MS_TO_TICKS(10));
191 ao_delay(AO_MS_TO_TICKS(10));
193 devstat = ao_mma655x_reg_read(AO_MMA655X_DEVSTAT);
194 PRINTD(DEBUG_HIGH, "devstat %x\n", devstat);
196 if (!(devstat & (1 << AO_MMA655X_DEVSTAT_DEVRES)))
199 /* Configure R/W register values.
200 * Most of them relate to the arming feature, which
201 * we don't use, so the only registers we need to
202 * write are DEVCFG and AXISCFG
205 ao_mma655x_reg_write(AO_MMA655X_DEVCFG,
206 DEVCFG_VALUE | (0 << AO_MMA655X_DEVCFG_ENDINIT));
211 ao_mma655x_reg_write(AO_MMA655X_AXISCFG,
213 (1 << AO_MMA655X_AXISCFG_ST));
214 ao_delay(AO_MS_TO_TICKS(10));
216 a_st = ao_mma655x_value();
218 ao_mma655x_reg_write(AO_MMA655X_AXISCFG,
220 (0 << AO_MMA655X_AXISCFG_ST));
222 ao_delay(AO_MS_TO_TICKS(10));
224 a = ao_mma655x_value();
226 st_change = a_st - a;
228 PRINTD(DEBUG_HIGH, "self test %d normal %d change %d\n", a_st, a, st_change);
230 if (AO_ST_MIN <= st_change && st_change <= AO_ST_MAX)
232 ao_delay(AO_ST_DELAY);
234 if (tries == AO_ST_TRIES)
235 AO_SENSOR_ERROR(AO_DATA_MMA655X);
237 ao_mma655x_reg_write(AO_MMA655X_DEVCFG,
238 DEVCFG_VALUE | (1 << AO_MMA655X_DEVCFG_ENDINIT));
240 s0 = ao_mma655x_reg_read(AO_MMA655X_SN0);
241 s1 = ao_mma655x_reg_read(AO_MMA655X_SN1);
242 s2 = ao_mma655x_reg_read(AO_MMA655X_SN2);
243 s3 = ao_mma655x_reg_read(AO_MMA655X_SN3);
244 lot = ((uint32_t) s3 << 24) | ((uint32_t) s2 << 16) |
245 ((uint32_t) s1 << 8) | ((uint32_t) s0);
246 serial = lot & 0x1fff;
248 pn = ao_mma655x_reg_read(AO_MMA655X_PN);
252 uint16_t ao_mma655x_current;
255 ao_mma655x_dump(void)
257 printf ("MMA655X value %d\n", ao_mma655x_current);
260 const struct ao_cmds ao_mma655x_cmds[] = {
261 { ao_mma655x_dump, "A\0Display MMA655X data" },
270 ao_mma655x_current = ao_mma655x_value();
272 AO_DATA_PRESENT(AO_DATA_MMA655X);
278 static struct ao_task ao_mma655x_task;
281 ao_mma655x_init(void)
283 ao_cmd_register(&ao_mma655x_cmds[0]);
284 ao_spi_init_cs(AO_MMA655X_CS_PORT, (1 << AO_MMA655X_CS_PIN));
286 ao_add_task(&ao_mma655x_task, ao_mma655x, "mma655x");