altos/lpc: Add ADC driver

Uses burst mode to get the whole set of values in one interrupt

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src/lpc/ao_adc_lpc.c b/src/lpc/ao_adc_lpc.c
new file mode 100644 (file)
index 0000000..70e8b2d
--- /dev/null
+++ b/src/lpc/ao_adc_lpc.c
@@ -0,0 +1,229 @@
+/*
+ * Copyright © 2012 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_data.h>
+
+#ifndef AO_ADC_0
+#define AO_ADC_0       0
+#endif
+
+#ifndef AO_ADC_1
+#define AO_ADC_1       0
+#endif
+
+#ifndef AO_ADC_2
+#define AO_ADC_2       0
+#endif
+
+#ifndef AO_ADC_3
+#define AO_ADC_3       0
+#endif
+
+#ifndef AO_ADC_4
+#define AO_ADC_4       0
+#endif
+
+#ifndef AO_ADC_5
+#define AO_ADC_5       0
+#endif
+
+#ifndef AO_ADC_6
+#define AO_ADC_6       0
+#endif
+
+#ifndef AO_ADC_7
+#define AO_ADC_7       0
+#endif
+
+#if AO_ADC_7
+# define AO_ADC_LAST           7
+#else
+# if AO_ADC_6
+#  define AO_ADC_LAST          6
+# else
+#  if AO_ADC_5
+#   define AO_ADC_LAST         5
+#  else
+#   if AO_ADC_4
+#    define AO_ADC_LAST                4
+#   else
+#    if AO_ADC_3
+#     define AO_ADC_LAST       3
+#    else
+#     if AO_ADC_2
+#      define AO_ADC_LAST      2
+#     else
+#      if AO_ADC_1
+#       define AO_ADC_LAST     1
+#      else
+#       if AO_ADC_0
+#        define AO_ADC_LAST    0
+#       endif
+#      endif
+#     endif
+#    endif
+#   endif
+#  endif
+# endif
+#endif
+
+static uint8_t                 ao_adc_ready;
+
+void  lpc_adc_isr(void)
+{
+       uint16_t        *out = (uint16_t *) &ao_data_ring[ao_data_head].adc;
+       vuint32_t       *in = &lpc_adc.dr[0];
+
+       /* Store converted values in packet */
+
+#if AO_ADC_0
+       *out++ = ((uint16_t) *in++) >> 1;
+#endif
+#if AO_ADC_1
+       *out++ = ((uint16_t) *in++) >> 1;
+#endif
+#if AO_ADC_2
+       *out++ = ((uint16_t) *in++) >> 1;
+#endif
+#if AO_ADC_3
+       *out++ = ((uint16_t) *in++) >> 1;
+#endif
+#if AO_ADC_4
+       *out++ = ((uint16_t) *in++) >> 1;
+#endif
+#if AO_ADC_5
+       *out++ = ((uint16_t) *in++) >> 1;
+#endif
+#if AO_ADC_6
+       *out++ = ((uint16_t) *in++) >> 1;
+#endif
+#if AO_ADC_7
+       *out++ = ((uint16_t) *in++) >> 1;
+#endif
+
+       AO_DATA_PRESENT(AO_DATA_ADC);
+       if (ao_data_present == AO_DATA_ALL) {
+#if HAS_MS5607
+               ao_data_ring[ao_data_head].ms5607_raw = ao_ms5607_current;
+#endif
+#if HAS_MMA655X
+               ao_data_ring[ao_data_head].mma655x = ao_mma655x_current;
+#endif
+#if HAS_HMC5883
+               ao_data_ring[ao_data_head].hmc5883 = ao_hmc5883_current;
+#endif
+#if HAS_MPU6000
+               ao_data_ring[ao_data_head].mpu6000 = ao_mpu6000_current;
+#endif
+               ao_data_ring[ao_data_head].tick = ao_tick_count;
+               ao_data_head = ao_data_ring_next(ao_data_head);
+               ao_wakeup((void *) &ao_data_head);
+       }
+       ao_adc_ready = 1;
+}
+
+#define AO_ADC_MASK    ((AO_ADC_0 << 0) |      \
+                        (AO_ADC_1 << 1) |      \
+                        (AO_ADC_2 << 2) |      \
+                        (AO_ADC_3 << 3) |      \
+                        (AO_ADC_4 << 4) |      \
+                        (AO_ADC_5 << 5) |      \
+                        (AO_ADC_6 << 6) |      \
+                        (AO_ADC_7 << 7))
+
+#define AO_ADC_CLKDIV  (AO_LPC_CLKOUT / 4500000)
+
+/*
+ * Start the ADC sequence using the DMA engine
+ */
+void
+ao_adc_poll(void)
+{
+       if (!ao_adc_ready)
+               return;
+       ao_adc_ready = 0;
+
+       lpc_adc.cr = ((AO_ADC_MASK << LPC_ADC_CR_SEL) |
+                     (AO_ADC_CLKDIV << LPC_ADC_CR_CLKDIV) |
+                     (1 << LPC_ADC_CR_BURST) |
+                     (LPC_ADC_CR_CLKS_11 << LPC_ADC_CR_CLKS));
+}
+
+static void
+ao_adc_dump(void) __reentrant
+{
+       struct ao_data  packet;
+       int16_t *d;
+       uint8_t i;
+
+       ao_data_get(&packet);
+#ifdef AO_ADC_DUMP
+       AO_ADC_DUMP(&packet);
+#else
+       printf("tick: %5u",  packet.tick);
+       d = (int16_t *) (&packet.adc);
+       for (i = 0; i < AO_NUM_ADC; i++)
+               printf (" %2d: %5d", i, d[i]);
+       printf("\n");
+#endif
+}
+
+__code struct ao_cmds ao_adc_cmds[] = {
+       { ao_adc_dump,  "a\0Display current ADC values" },
+       { 0, NULL },
+};
+
+void
+ao_adc_init(void)
+{
+       lpc_scb.sysahbclkctrl |= (1 << LPC_SCB_SYSAHBCLKCTRL_ADC);
+       lpc_scb.pdruncfg &= ~(1 << LPC_SCB_PDRUNCFG_ADC_PD);
+
+       /* Enable interrupt when last channel is complete */
+       lpc_adc.inten = (1 << AO_ADC_LAST);
+
+       lpc_nvic_set_enable(LPC_ISR_ADC_POS);
+       lpc_nvic_set_priority(LPC_ISR_ADC_POS, AO_LPC_NVIC_CLOCK_PRIORITY);
+#if AO_ADC_0
+       ao_enable_analog(0, 11);
+#endif
+#if AO_ADC_1
+       ao_enable_analog(0, 12);
+#endif
+#if AO_ADC_2
+       ao_enable_analog(0, 13);
+#endif
+#if AO_ADC_3
+       ao_enable_analog(0, 14);
+#endif
+#if AO_ADC_4
+       ao_enable_analog(0, 14);
+#endif
+#if AO_ADC_5
+       ao_enable_analog(0, 14);
+#endif
+#if AO_ADC_6
+       ao_enable_analog(0, 14);
+#endif
+#if AO_ADC_7
+       ao_enable_analog(0, 14);
+#endif
+       ao_cmd_register(&ao_adc_cmds[0]);
+
+       ao_adc_ready = 1;
+}