Add support for board version reading via ADC
diff --git a/firmware/src_board/boardver_adc.c b/firmware/src_board/boardver_adc.c
new file mode 100644
index 0000000..ca3d1fe
--- /dev/null
+++ b/firmware/src_board/boardver_adc.c
@@ -0,0 +1,83 @@
+#include "board.h"
+#include "boardver_adc.h"
+
+/* FIXME: share this with mode_cardemu.c */
+#define UV_PER_LSB ((3300 * 1000) / 4096)
+static uint32_t adc2uv(uint16_t adc)
+{
+ uint32_t uv = (uint32_t) adc * UV_PER_LSB;
+ return uv;
+}
+
+/***********************************************************************
+ * ADC for board version detection
+ ***********************************************************************/
+
+#ifdef PIN_VERSION_DET
+
+static int adc_sam3s_reva_errata = 0;
+
+static const Pin pin_version_det = PIN_VERSION_DET;
+
+/* Warning: Don't call this while other code (like the SIM VCC voltage
+ * reading) is running. The idea is you call this once during board
+ * startup and cache the result in a (global) variable if you need it
+ * later throughout the code */
+int get_board_version_adc(void)
+{
+ uint32_t chip_arch = CHIPID->CHIPID_CIDR & CHIPID_CIDR_ARCH_Msk;
+ uint32_t chip_ver = CHIPID->CHIPID_CIDR & CHIPID_CIDR_VERSION_Msk;
+ uint16_t sample;
+ uint32_t uv;
+
+ PIO_Configure(&pin_version_det, 1);
+
+ PMC_EnablePeripheral(ID_ADC);
+
+ ADC->ADC_CR |= ADC_CR_SWRST;
+ if (chip_ver == 0 &&
+ (chip_arch == CHIPID_CIDR_ARCH_SAM3SxA ||
+ chip_arch == CHIPID_CIDR_ARCH_SAM3SxB ||
+ chip_arch == CHIPID_CIDR_ARCH_SAM3SxC)) {
+ TRACE_INFO("Enabling Rev.A ADC Errata work-around\r\n");
+ adc_sam3s_reva_errata = 1;
+ }
+
+ if (adc_sam3s_reva_errata) {
+ /* Errata Work-Around to clear EOCx flags */
+ volatile uint32_t foo;
+ int i;
+ for (i = 0; i < 16; i++)
+ foo = ADC->ADC_CDR[i];
+ }
+
+ /* Initialize ADC for AD2, fADC=48/24=2MHz */
+ ADC->ADC_MR = ADC_MR_TRGEN_DIS | ADC_MR_LOWRES_BITS_12 |
+ ADC_MR_SLEEP_NORMAL | ADC_MR_FWUP_OFF |
+ ADC_MR_FREERUN_OFF | ADC_MR_PRESCAL(23) |
+ ADC_MR_STARTUP_SUT8 | ADC_MR_SETTLING(3) |
+ ADC_MR_ANACH_NONE | ADC_MR_TRACKTIM(4) |
+ ADC_MR_TRANSFER(1) | ADC_MR_USEQ_NUM_ORDER;
+ /* enable AD2 channel only */
+ ADC->ADC_CHER = ADC_CHER_CH2;
+
+ /* Make sure we don't use interrupts as that's what the SIM card
+ * VCC ADC code is using */
+ ADC->ADC_IER = 0;
+ NVIC_DisableIRQ(ADC_IRQn);
+
+ ADC->ADC_CR |= ADC_CR_START;
+
+ /* busy-wait, actually read the value */
+ do { } while (!(ADC->ADC_ISR & ADC_ISR_EOC2));
+ /* convert to voltage */
+ sample = ADC->ADC_CDR[2];
+ uv = adc2uv(sample);
+ TRACE_INFO("VERSION_DET ADC=%u => %u uV\r\n", sample, uv);
+
+ /* FIXME: convert to board version based on thresholds */
+
+ return 0;
+}
+
+#endif /* PIN_VERSION_DET */