Resurrect ADC support.

Standard refactoring: add series headers for F1 and F2, along with
series adc.c files. There are some issues relating to adc_extsel_event
to hammer out later, but this will do for now.

We also add some new portability interfaces to libmaple/adc.h in order
for Wirish to use the same code to initialize the ADCs at init() time.

As usual, F1 is untested.

Signed-off-by: Marti Bolivar <mbolivar@leaflabs.com>

13 files changed, 920 insertions, 214 deletions

diff --git a/libmaple/adc.c b/libmaple/adc.c
index 40369e9..acce923 100644
--- a/libmaple/adc.c
+++ b/libmaple/adc.c
@@ -25,44 +25,15 @@
  *****************************************************************************/
 
 /**
- * @file adc.c
- *
+ * @file libmaple/adc.c
+ * @author Marti Bolivar <mbolivar@leaflabs.com>,
+ *         Perry Hung <perry@leaflabs.com>
  * @brief Analog to digital converter routines
- *
- * IMPORTANT: maximum external impedance must be below 0.4kOhms for 1.5
- * sample conversion time.
- *
- * At 55.5 cycles/sample, the external input impedance < 50kOhms.
- *
- * See STM32 manual RM0008 for how to calculate this.
  */
 
+#include <libmaple/adc.h>
 #include <libmaple/libmaple.h>
 #include <libmaple/rcc.h>
-#include <libmaple/adc.h>
-
-static adc_dev adc1 = {
-    .regs   = ADC1_BASE,
-    .clk_id = RCC_ADC1
-};
-/** ADC1 device. */
-const adc_dev *ADC1 = &adc1;
-
-static adc_dev adc2 = {
-    .regs   = ADC2_BASE,
-    .clk_id = RCC_ADC2
-};
-/** ADC2 device. */
-const adc_dev *ADC2 = &adc2;
-
-#ifdef STM32_HIGH_DENSITY
-adc_dev adc3 = {
-    .regs   = ADC3_BASE,
-    .clk_id = RCC_ADC3
-};
-/** ADC3 device. */
-const adc_dev *ADC3 = &adc3;
-#endif
 
 /**
  * @brief Initialize an ADC peripheral.
@@ -91,20 +62,10 @@ void adc_set_extsel(const adc_dev *dev, adc_extsel_event event) {
 }
 
 /**
- * @brief Call a function on all ADC devices.
- * @param fn Function to call on each ADC device.
- */
-void adc_foreach(void (*fn)(const adc_dev*)) {
-    fn(ADC1);
-    fn(ADC2);
-#ifdef STM32_HIGH_DENSITY
-    fn(ADC3);
-#endif
-}
-
-/**
- * @brief Turn the given sample rate into values for ADC_SMPRx. Don't
- * call this during conversion.
+ * @brief Set the sample rate for all channels on an ADC device.
+ *
+ * Don't call this during conversion.
+ *
  * @param dev adc device
  * @param smp_rate sample rate to set
  * @see adc_smp_rate
@@ -127,25 +88,8 @@ void adc_set_sample_rate(const adc_dev *dev, adc_smp_rate smp_rate) {
 }
 
 /**
- * @brief Calibrate an ADC peripheral
- * @param dev adc device
- */
-void adc_calibrate(const adc_dev *dev) {
-    __io uint32 *rstcal_bit = bb_perip(&(dev->regs->CR2), 3);
-    __io uint32 *cal_bit = bb_perip(&(dev->regs->CR2), 2);
-
-    *rstcal_bit = 1;
-    while (*rstcal_bit)
-        ;
-
-    *cal_bit = 1;
-    while (*cal_bit)
-        ;
-}
-
-/**
  * @brief Perform a single synchronous software triggered conversion on a
- * channel.
+ *        channel.
  * @param dev ADC device to use for reading.
  * @param channel channel to convert
  * @return conversion result
diff --git a/libmaple/include/libmaple/adc.h b/libmaple/include/libmaple/adc.h
index d531d00..be29676 100644
--- a/libmaple/include/libmaple/adc.h
+++ b/libmaple/include/libmaple/adc.h
@@ -1,6 +1,7 @@
 /******************************************************************************
  * The MIT License
  *
+ * Copyright (c) 2012 LeafLabs, LLC.
  * Copyright (c) 2010 Perry Hung.
  *
  * Permission is hereby granted, free of charge, to any person
@@ -25,9 +26,10 @@
  *****************************************************************************/
 
 /**
- *  @file adc.h
- *
- *  @brief Analog-to-Digital Conversion (ADC) header.
+ * @file libmaple/adc.h
+ * @author Marti Bolivar <mbolivar@leaflabs.com>,
+ *         Perry Hung <perry@leaflabs.com>
+ * @brief Analog-to-Digital Conversion (ADC) header.
  */
 
 #ifndef _LIBMAPLE_ADC_H_
@@ -40,6 +42,12 @@ extern "C"{
 #include <libmaple/libmaple.h>
 #include <libmaple/bitband.h>
 #include <libmaple/rcc.h>
+/* We include the series header below, after defining the register map
+ * and device structs. */
+
+/*
+ * Register map
+ */
 
 /** ADC register map type. */
 typedef struct adc_reg_map {
@@ -71,24 +79,30 @@ typedef struct adc_dev {
     rcc_clk_id clk_id; /**< RCC clock information */
 } adc_dev;
 
-extern const adc_dev *ADC1;
-extern const adc_dev *ADC2;
-#ifdef STM32_HIGH_DENSITY
-extern const adc_dev *ADC3;
-#endif
-
-/*
- * Register map base pointers
+/* Pull in the series header (which may need the above struct
+ * definitions).
+ *
+ * IMPORTANT: The series header must define the following:
+ *
+ * - enum adc_extsel_event (and typedef to adc_extsel_event): One per
+ *   external event used to trigger start of conversion of a regular
+ *   group. If two different series support the same event as a
+ *   trigger, they must use the same token for the enumerator for that
+ *   event. (The value of the enumerator is of course allowed to be
+ *   different).
+ *
+ * - enum adc_smp_rate (and typedef to adc_smp_rate): One per
+ *   available sampling time.  These must be in the form ADC_SMPR_X_Y
+ *   for X.Y cycles (e.g. ADC_SMPR_1_5 means 1.5 cycles), or
+ *   ADC_SMPR_X for X cycles (e.g. ADC_SMPR_3 means 3 cycles).
+ *
+ * - enum adc_prescaler (and typedef): One per available prescaler,
+ *   suitable for adc_set_prescaler. Series which have the same
+ *   prescaler dividers (e.g. STM32F1 and STM32F2 both divide PCLK2 by
+ *   2, 4, 6, or 8) must provide the same tokens as enumerators, for
+ *   portability.
  */
-
-/** ADC1 register map base pointer. */
-#define ADC1_BASE                       ((struct adc_reg_map*)0x40012400)
-/** ADC2 register map base pointer. */
-#define ADC2_BASE                       ((struct adc_reg_map*)0x40012800)
-#ifdef STM32_HIGH_DENSITY
-/** ADC3 register map base pointer. */
-#define ADC3_BASE                       ((struct adc_reg_map*)0x40013C00)
-#endif
+#include <series/adc.h>
 
 /*
  * Register bit definitions
@@ -136,31 +150,9 @@ extern const adc_dev *ADC3;
 
 /* Control register 2 */
 
-#define ADC_CR2_ADON_BIT                0
-#define ADC_CR2_CONT_BIT                1
-#define ADC_CR2_CAL_BIT                 2
-#define ADC_CR2_RSTCAL_BIT              3
-#define ADC_CR2_DMA_BIT                 8
-#define ADC_CR2_ALIGN_BIT               11
-#define ADC_CR2_JEXTTRIG_BIT            15
-#define ADC_CR2_EXTTRIG_BIT             20
-#define ADC_CR2_JSWSTART_BIT            21
-#define ADC_CR2_SWSTART_BIT             22
-#define ADC_CR2_TSEREFE_BIT             23
-
-#define ADC_CR2_ADON                    BIT(ADC_CR2_ADON_BIT)
-#define ADC_CR2_CONT                    BIT(ADC_CR2_CONT_BIT)
-#define ADC_CR2_CAL                     BIT(ADC_CR2_CAL_BIT)
-#define ADC_CR2_RSTCAL                  BIT(ADC_CR2_RSTCAL_BIT)
-#define ADC_CR2_DMA                     BIT(ADC_CR2_DMA_BIT)
-#define ADC_CR2_ALIGN                   BIT(ADC_CR2_ALIGN_BIT)
-#define ADC_CR2_JEXTSEL                 (0x7000)
-#define ADC_CR2_JEXTTRIG                BIT(ADC_CR2_JEXTTRIG_BIT)
-#define ADC_CR2_EXTSEL                  (0xE0000)
-#define ADC_CR2_EXTTRIG                 BIT(ADC_CR2_EXTTRIG_BIT)
-#define ADC_CR2_JSWSTART                BIT(ADC_CR2_JSWSTART_BIT)
-#define ADC_CR2_SWSTART                 BIT(ADC_CR2_SWSTART_BIT)
-#define ADC_CR2_TSEREFE                 BIT(ADC_CR2_TSEREFE_BIT)
+/* Because this register varies significantly by series (e.g. some
+ * bits moved and others disappeared in the F1->F2 transition), its
+ * definitions are in the series headers. */
 
 /* Sample time register 1 */
 
@@ -245,68 +237,47 @@ extern const adc_dev *ADC3;
 #define ADC_DR_ADC2DATA                 (0xFFFF << 16)
 #define ADC_DR_DATA                     0xFFFF
 
-void adc_init(const adc_dev *dev);
+/*
+ * Routines
+ */
 
 /**
- * @brief External event selector for regular group conversion.
- * @see adc_set_extsel
+ * @brief Set the ADC prescaler.
+ *
+ * This determines the ADC clock for all devices.
  */
-typedef enum adc_extsel_event {
-    ADC_ADC12_TIM1_CC1  = (0 << 17), /**< ADC1 and ADC2: Timer 1 CC1 event */
-    ADC_ADC12_TIM1_CC2  = (1 << 17), /**< ADC1 and ADC2: Timer 1 CC2 event */
-    ADC_ADC12_TIM1_CC3  = (2 << 17), /**< ADC1 and ADC2: Timer 1 CC3 event */
-    ADC_ADC12_TIM2_CC2  = (3 << 17), /**< ADC1 and ADC2: Timer 2 CC2 event */
-    ADC_ADC12_TIM3_TRGO = (4 << 17), /**< ADC1 and ADC2: Timer 3 TRGO event */
-    ADC_ADC12_TIM4_CC4  = (5 << 17), /**< ADC1 and ADC2: Timer 4 CC4 event */
-    ADC_ADC12_EXTI11    = (6 << 17), /**< ADC1 and ADC2: EXTI11 event */
-#ifdef STM32_HIGH_DENSITY
-    ADC_ADC12_TIM8_TRGO = (6 << 17), /**< ADC1 and ADC2: Timer 8 TRGO
-                                        event (high density only) */
-#endif
-    ADC_ADC12_SWSTART   = (7 << 17), /**< ADC1 and ADC2: Software start */
-#ifdef STM32_HIGH_DENSITY
-    ADC_ADC3_TIM3_CC1   = (0 << 17), /**< ADC3: Timer 3 CC1 event
-                                        (high density only) */
-    ADC_ADC3_TIM2_CC3   = (1 << 17), /**< ADC3: Timer 2 CC3 event
-                                        (high density only) */
-    ADC_ADC3_TIM1_CC3   = (2 << 17), /**< ADC3: Timer 1 CC3 event
-                                        (high density only) */
-    ADC_ADC3_TIM8_CC1   = (3 << 17), /**< ADC3: Timer 8 CC1 event
-                                        (high density only) */
-    ADC_ADC3_TIM8_TRGO  = (4 << 17), /**< ADC3: Timer 8 TRGO event
-                                        (high density only) */
-    ADC_ADC3_TIM5_CC1   = (5 << 17), /**< ADC3: Timer 5 CC1 event
-                                        (high density only) */
-    ADC_ADC3_TIM5_CC3   = (6 << 17), /**< ADC3: Timer 5 CC3 event
-                                        (high density only) */
-    ADC_ADC3_SWSTART    = (7 << 17), /**< ADC3: Software start (high
-                                        density only) */
-#endif
-    ADC_SWSTART         = (7 << 17) /**< ADC1, ADC2, ADC3: Software start */
-} adc_extsel_event;
+void adc_set_prescaler(adc_prescaler pre);
 
+void adc_init(const adc_dev *dev);
 void adc_set_extsel(const adc_dev *dev, adc_extsel_event event);
+void adc_set_sample_rate(const adc_dev *dev, adc_smp_rate smp_rate);
+uint16 adc_read(const adc_dev *dev, uint8 channel);
+
+/**
+ * @brief Call a function on all ADC devices.
+ * @param fn Function to call on each ADC device.
+ */
 void adc_foreach(void (*fn)(const adc_dev*));
 
 /**
- * @brief ADC sample times, in ADC clock cycles
- *
- * These control the amount of time spent sampling the input voltage.
+ * @brief Configure a GPIO pin for ADC conversion.
+ * @param gdev GPIO device to configure.
+ * @param bit Bit on gdev to configure for ADC conversion.
  */
-typedef enum {
-    ADC_SMPR_1_5,               /**< 1.5 ADC cycles */
-    ADC_SMPR_7_5,               /**< 7.5 ADC cycles */
-    ADC_SMPR_13_5,              /**< 13.5 ADC cycles */
-    ADC_SMPR_28_5,              /**< 28.5 ADC cycles */
-    ADC_SMPR_41_5,              /**< 41.5 ADC cycles */
-    ADC_SMPR_55_5,              /**< 55.5 ADC cycles */
-    ADC_SMPR_71_5,              /**< 71.5 ADC cycles */
-    ADC_SMPR_239_5              /**< 239.5 ADC cycles */
-} adc_smp_rate;
+struct gpio_dev;
+void adc_gpio_cfg(struct gpio_dev *gdev, uint8 bit);
 
-void adc_set_sample_rate(const adc_dev *dev, adc_smp_rate smp_rate);
-void adc_calibrate(const adc_dev *dev);
-uint16 adc_read(const adc_dev *dev, uint8 channel);
+/**
+ * @brief Enable an ADC and configure it for single conversion mode.
+ *
+ * This function performs any initialization necessary to allow the
+ * ADC device to perform a single synchronous regular software
+ * triggered conversion, using adc_read().
+ *
+ * @param dev Device to enable.
+ * @see adc_read()
+ */
+void adc_enable_single_swstart(const adc_dev* dev);
 
 /**
  * @brief Set the regular channel sequence length.
@@ -325,16 +296,6 @@ static inline void adc_set_reg_seqlen(const adc_dev *dev, uint8 length) {
 }
 
 /**
- * @brief Set external trigger conversion mode event for regular channels
- * @param dev    ADC device
- * @param enable If 1, conversion on external events is enabled; if 0,
- *               disabled.
- */
-static inline void adc_set_exttrig(const adc_dev *dev, uint8 enable) {
-    *bb_perip(&dev->regs->CR2, ADC_CR2_EXTTRIG_BIT) = !!enable;
-}
-
-/**
  * @brief Enable an adc peripheral
  * @param dev ADC device to enable
  */
diff --git a/libmaple/rules.mk b/libmaple/rules.mk
index cc562ea..d118b16 100644
--- a/libmaple/rules.mk
+++ b/libmaple/rules.mk
@@ -11,7 +11,8 @@ LIBMAPLE_PRIVATE_INCLUDES := -I$(LIBMAPLE_PATH)
 CFLAGS_$(d) = $(LIBMAPLE_PRIVATE_INCLUDES) $(LIBMAPLE_INCLUDES) -Wall -Werror
 
 # Local rules and targets
-cSRCS_$(d) := flash.c
+cSRCS_$(d) := adc.c
+cSRCS_$(d) += flash.c
 cSRCS_$(d) += gpio.c
 cSRCS_$(d) += iwdg.c
 cSRCS_$(d) += nvic.c
@@ -23,7 +24,6 @@ cSRCS_$(d) += usart.c
 cSRCS_$(d) += usart_private.c
 cSRCS_$(d) += util.c
 # These still need to be ported to F2:
-# cSRCS_$(d) += adc.c
 # cSRCS_$(d) += dac.c
 # cSRCS_$(d) += dma.c
 # cSRCS_$(d) += exti.c
diff --git a/libmaple/stm32f1/adc.c b/libmaple/stm32f1/adc.c
new file mode 100644
index 0000000..8242520
--- /dev/null
+++ b/libmaple/stm32f1/adc.c
@@ -0,0 +1,110 @@
+/******************************************************************************
+ * The MIT License
+ *
+ * Copyright (c) 2012 LeafLabs, LLC.
+ * Copyright (c) 2010 Perry Hung.
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy,
+ * modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *****************************************************************************/
+
+/**
+ * @file libmaple/stm32f1/include/series/adc.c
+ * @brief STM32F1 ADC header.
+ */
+
+#include <libmaple/adc.h>
+#include <libmaple/gpio.h>
+
+/*
+ * Devices
+ */
+
+static adc_dev adc1 = {
+    .regs   = ADC1_BASE,
+    .clk_id = RCC_ADC1
+};
+/** ADC1 device. */
+const adc_dev *ADC1 = &adc1;
+
+static adc_dev adc2 = {
+    .regs   = ADC2_BASE,
+    .clk_id = RCC_ADC2
+};
+/** ADC2 device. */
+const adc_dev *ADC2 = &adc2;
+
+#ifdef STM32_HIGH_DENSITY
+adc_dev adc3 = {
+    .regs   = ADC3_BASE,
+    .clk_id = RCC_ADC3
+};
+/** ADC3 device. */
+const adc_dev *ADC3 = &adc3;
+#endif
+
+/*
+ * STM32F1 routines
+ */
+
+/**
+ * @brief Calibrate an ADC peripheral
+ * @param dev adc device
+ */
+void adc_calibrate(const adc_dev *dev) {
+    __io uint32 *rstcal_bit = bb_perip(&(dev->regs->CR2), 3);
+    __io uint32 *cal_bit = bb_perip(&(dev->regs->CR2), 2);
+
+    *rstcal_bit = 1;
+    while (*rstcal_bit)
+        ;
+
+    *cal_bit = 1;
+    while (*cal_bit)
+        ;
+}
+
+/*
+ * Common routines
+ */
+
+void adc_set_prescaler(adc_prescaler pre) {
+    rcc_set_prescaler(RCC_PRESCALER_ADC, (uint32)pre);
+}
+
+void adc_foreach(void (*fn)(const adc_dev*)) {
+    fn(ADC1);
+    fn(ADC2);
+#ifdef STM32_HIGH_DENSITY
+    fn(ADC3);
+#endif
+}
+
+void adc_gpio_cfg(gpio_dev *gdev, uint8 bit) {
+    gpio_set_mode(gdev, bit, GPIO_INPUT_ANALOG);
+}
+
+void adc_enable_single_swstart(const adc_dev *dev) {
+    adc_init(dev);
+    adc_set_extsel(dev, ADC_SWSTART);
+    adc_set_exttrig(dev, 1);
+    adc_enable(dev);
+    adc_calibrate(dev);
+}
diff --git a/libmaple/stm32f1/include/series/adc.h b/libmaple/stm32f1/include/series/adc.h
new file mode 100644
index 0000000..1798e55
--- /dev/null
+++ b/libmaple/stm32f1/include/series/adc.h
@@ -0,0 +1,254 @@
+/******************************************************************************
+ * The MIT License
+ *
+ * Copyright (c) 2012 LeafLabs, LLC.
+ * Copyright (c) 2010 Perry Hung.
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy,
+ * modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *****************************************************************************/
+
+/**
+ * @file stm32f1/include/series/adc.h
+ * @author Marti Bolivar <mbolivar@leaflabs.com>,
+ *         Perry Hung <perry@leaflabs.com>
+ * @brief STM32F1 ADC header.
+ */
+
+#ifndef _LIBMAPLE_STM32F1_ADC_H_
+#define _LIBMAPLE_STM32F1_ADC_H_
+
+#include <libmaple/rcc.h>       /* For the prescalers */
+
+/*
+ * Devices
+ */
+
+extern const struct adc_dev *ADC1;
+extern const struct adc_dev *ADC2;
+#ifdef STM32_HIGH_DENSITY
+extern const struct adc_dev *ADC3;
+#endif
+
+/*
+ * Register map base pointers
+ */
+
+/** ADC1 register map base pointer. */
+#define ADC1_BASE                       ((struct adc_reg_map*)0x40012400)
+/** ADC2 register map base pointer. */
+#define ADC2_BASE                       ((struct adc_reg_map*)0x40012800)
+#ifdef STM32_HIGH_DENSITY
+/** ADC3 register map base pointer. */
+#define ADC3_BASE                       ((struct adc_reg_map*)0x40013C00)
+#endif
+
+/*
+ * Register bit definitions
+ */
+
+/* Control register 2 */
+
+#define ADC_CR2_ADON_BIT                0
+#define ADC_CR2_CONT_BIT                1
+#define ADC_CR2_CAL_BIT                 2
+#define ADC_CR2_RSTCAL_BIT              3
+#define ADC_CR2_DMA_BIT                 8
+#define ADC_CR2_ALIGN_BIT               11
+#define ADC_CR2_JEXTTRIG_BIT            15
+#define ADC_CR2_EXTTRIG_BIT             20
+#define ADC_CR2_JSWSTART_BIT            21
+#define ADC_CR2_SWSTART_BIT             22
+#define ADC_CR2_TSEREFE_BIT             23
+
+#define ADC_CR2_ADON                    (1U << ADC_CR2_ADON_BIT)
+#define ADC_CR2_CONT                    (1U << ADC_CR2_CONT_BIT)
+#define ADC_CR2_CAL                     (1U << ADC_CR2_CAL_BIT)
+#define ADC_CR2_RSTCAL                  (1U << ADC_CR2_RSTCAL_BIT)
+#define ADC_CR2_DMA                     (1U << ADC_CR2_DMA_BIT)
+#define ADC_CR2_ALIGN                   (1U << ADC_CR2_ALIGN_BIT)
+#define ADC_CR2_JEXTSEL                 0x7000
+#define ADC_CR2_JEXTTRIG                (1U << ADC_CR2_JEXTTRIG_BIT)
+#define ADC_CR2_EXTSEL                  0xE0000
+#define ADC_CR2_EXTTRIG                 (1U << ADC_CR2_EXTTRIG_BIT)
+#define ADC_CR2_JSWSTART                (1U << ADC_CR2_JSWSTART_BIT)
+#define ADC_CR2_SWSTART                 (1U << ADC_CR2_SWSTART_BIT)
+#define ADC_CR2_TSEREFE                 (1U << ADC_CR2_TSEREFE_BIT)
+
+/*
+ * Other types
+ */
+
+/**
+ * @brief STM32F1 external event selectors for regular group
+ *        conversion.
+ *
+ * Some external events are only available on ADCs 1 and 2, others
+ * only on ADC3, while others are available on all three ADCs.
+ * Additionally, some events are only available on high- and
+ * XL-density STM32F1 MCUs, as they use peripherals only available on
+ * those MCU densities.
+ *
+ * For ease of use, each event selector is given along with the ADCs
+ * it's available on, along with any other availability restrictions.
+ *
+ * @see adc_set_extsel()
+ */
+typedef enum adc_extsel_event {
+    /* TODO: Smarten this up a bit, as follows.
+     *
+     * The EXTSEL bits on F1 are a little brain-damaged in that the
+     * TIM8 TRGO event has different bits depending on whether you're
+     * using ADC1/2 or ADC3.  We route around this by declaring two
+     * enumerators, ADC_EXT_EV_ADC12_TIM8_TRGO and
+     * ADC_EXT_EV_ADC3_TIM8_TRGO.
+     *
+     * The right thing to do is to provide a single
+     * ADC_EXT_EV_TIM8_TRGO enumerator and override adc_set_extsel on
+     * STM32F1 to handle this situation correctly. We can do that
+     * later, though, and change the per-ADC enumerator values to
+     * ADC_EXT_EV_TIM8_TRGO to preserve compatibility. */
+
+    /* ADC1 and ADC2 only: */
+    ADC_EXT_EV_TIM1_CC1  = 0x00000, /**< ADC1, ADC2: Timer 1 CC1 event */
+    ADC_EXT_EV_TIM1_CC2  = 0x20000, /**< ADC1, ADC2: Timer 1 CC2 event */
+    ADC_EXT_EV_TIM2_CC2  = 0x60000, /**< ADC1, ADC2: Timer 2 CC2 event */
+    ADC_EXT_EV_TIM3_TRGO = 0x80000, /**< ADC1, ADC2: Timer 3 TRGO event */
+    ADC_EXT_EV_TIM4_CC4  = 0xA0000, /**< ADC1, ADC2: Timer 4 CC4 event */
+    ADC_EXT_EV_EXTI11    = 0xC0000, /**< ADC1, ADC2: EXTI11 event */
+
+    /* Common: */
+    ADC_EXT_EV_TIM1_CC3  = 0x40000, /**< ADC1, ADC2, ADC3: Timer 1 CC3 event */
+    ADC_EXT_EV_SWSTART   = 0xE0000, /**< ADC1, ADC2, ADC3: Software start */
+
+    /* HD only: */
+    ADC_EXT_EV_TIM3_CC1  = 0x00000, /**<
+                                     * ADC3: Timer 3 CC1 event
+                                     * Availability: high- and XL-density. */
+    ADC_EXT_EV_TIM2_CC3  = 0x20000, /**<
+                                     * ADC3: Timer 2 CC3 event
+                                     * Availability: high- and XL-density. */
+    ADC_EXT_EV_TIM8_CC1  = 0x60000, /**<
+                                     * ADC3: Timer 8 CC1 event
+                                     * Availability: high- and XL-density. */
+    ADC_EXT_EV_ADC3_TIM8_TRGO = 0x80000, /**<
+                                     * ADC3: Timer 8 TRGO event
+                                     * Availability: high- and XL-density. */
+    ADC_EXT_EV_TIM5_CC1  = 0xA0000, /**<
+                                     * ADC3: Timer 5 CC1 event
+                                     * Availability: high- and XL-density. */
+    ADC_EXT_EV_ADC12_TIM8_TRGO = 0xC0000, /**<
+                                     * ADC1, ADC2: Timer 8 TRGO event
+                                     * Availability: high- and XL-density. */
+    ADC_EXT_EV_TIM5_CC3  = 0xC0000, /**<
+                                     * ADC3: Timer 5 CC3 event
+                                     * Availability: high- and XL-density. */
+} adc_extsel_event;
+
+/* We'll keep these old adc_extsel_event enumerators around for a
+ * while, for backwards compatibility: */
+/** Deprecated. Use ADC_EXT_EV_TIM1_CC1 instead. */
+#define ADC_ADC12_TIM1_CC1  ADC_EXT_EV_TIM1_CC1
+/** Deprecated. Use ADC_EXT_EV_TIM1_CC2 instead. */
+#define ADC_ADC12_TIM1_CC2  ADC_EXT_EV_TIM1_CC2
+/** Deprecated. Use ADC_EXT_EV_TIM1_CC3 instead. */
+#define ADC_ADC12_TIM1_CC3  ADC_EXT_EV_TIM1_CC3
+/** Deprecated. Use ADC_EXT_EV_TIM2_CC2 instead. */
+#define ADC_ADC12_TIM2_CC2  ADC_EXT_EV_TIM2_CC2
+/** Deprecated. Use ADC_EXT_EV_TIM3_TRGO instead. */
+#define ADC_ADC12_TIM3_TRGO ADC_EXT_EV_TIM3_TRGO
+/** Deprecated. Use ADC_EXT_EV_TIM4_CC4 instead. */
+#define ADC_ADC12_TIM4_CC4  ADC_EXT_EV_TIM4_CC4
+/** Deprecated. Use ADC_EXT_EV_EXTI11 instead. */
+#define ADC_ADC12_EXTI11    ADC_EXT_EV_EXTI11
+/** Deprecated. Use ADC_EXT_EV_ADC12_TIM8_TRGO instead. */
+#define ADC_ADC12_TIM8_TRGO ADC_EXT_EV_ADC12_TIM8_TRGO
+/** Deprecated. Use ADC_EXT_EV_SWSTART instead. */
+#define ADC_ADC12_SWSTART   ADC_EXT_EV_SWSTART
+/** Deprecated. Use ADC_EXT_EV_TIM1_CC1 instead. */
+#define ADC_ADC3_TIM3_CC1   ADC_EXT_EV_TIM1_CC1
+/** Deprecated. Use ADC_EXT_EV_TIM1_CC2 instead. */
+#define ADC_ADC3_TIM2_CC3   ADC_EXT_EV_TIM1_CC2
+/** Deprecated. Use ADC_EXT_EV_TIM1_CC3 instead. */
+#define ADC_ADC3_TIM1_CC3   ADC_EXT_EV_TIM1_CC3
+/** Deprecated. Use ADC_EXT_EV_TIM2_CC2 instead. */
+#define ADC_ADC3_TIM8_CC1   ADC_EXT_EV_TIM2_CC2
+/** Deprecated. Use ADC_EXT_EV_TIM3_TRGO instead. */
+#define ADC_ADC3_TIM8_TRGO  ADC_EXT_EV_TIM3_TRGO
+/** Deprecated. Use ADC_EXT_EV_TIM4_CC4 instead. */
+#define ADC_ADC3_TIM5_CC1   ADC_EXT_EV_TIM4_CC4
+/** Deprecated. Use ADC_EXT_EV_EXTI11 instead. */
+#define ADC_ADC3_TIM5_CC3   ADC_EXT_EV_EXTI11
+/** Deprecated. Use ADC_EXT_EV_TIM8_TRGO instead. */
+#define ADC_ADC3_SWSTART    ADC_EXT_EV_TIM8_TRGO
+/** Deprecated. Use ADC_EXT_EV_SWSTART instead. */
+#define ADC_SWSTART         ADC_EXT_EV_SWSTART
+
+/**
+ * @brief STM32F1 sample times, in ADC clock cycles.
+ *
+ * These control the amount of time spent sampling the input voltage.
+ *
+ * IMPORTANT: maximum external impedance must be below 0.4kOhms for
+ * 1.5 cycle sampling time. At 55.5 cycles/sample, the external input
+ * impedance must be at most 50kOhms. See your device's datasheet for
+ * more information.
+ */
+typedef enum adc_smp_rate {
+    ADC_SMPR_1_5,               /**< 1.5 ADC cycles */
+    ADC_SMPR_7_5,               /**< 7.5 ADC cycles */
+    ADC_SMPR_13_5,              /**< 13.5 ADC cycles */
+    ADC_SMPR_28_5,              /**< 28.5 ADC cycles */
+    ADC_SMPR_41_5,              /**< 41.5 ADC cycles */
+    ADC_SMPR_55_5,              /**< 55.5 ADC cycles */
+    ADC_SMPR_71_5,              /**< 71.5 ADC cycles */
+    ADC_SMPR_239_5,             /**< 239.5 ADC cycles */
+} adc_smp_rate;
+
+/**
+ * @brief STM32F1 ADC prescalers, as divisors of PCLK2.
+ */
+typedef enum adc_prescaler {
+    ADC_PRE_PCLK2_DIV_2 = RCC_ADCPRE_PCLK_DIV_2, /** PCLK2 divided by 2 */
+    ADC_PRE_PCLK2_DIV_4 = RCC_ADCPRE_PCLK_DIV_4, /** PCLK2 divided by 4 */
+    ADC_PRE_PCLK2_DIV_6 = RCC_ADCPRE_PCLK_DIV_6, /** PCLK2 divided by 6 */
+    ADC_PRE_PCLK2_DIV_8 = RCC_ADCPRE_PCLK_DIV_8, /** PCLK2 divided by 8 */
+} adc_prescaler;
+
+/*
+ * Routines
+ */
+
+void adc_calibrate(const adc_dev *dev);
+
+/**
+ * @brief Set external trigger conversion mode event for regular channels
+ *
+ * Availability: STM32F1.
+ *
+ * @param dev    ADC device
+ * @param enable If 1, conversion on external events is enabled; if 0,
+ *               disabled.
+ */
+static inline void adc_set_exttrig(const adc_dev *dev, uint8 enable) {
+    *bb_perip(&dev->regs->CR2, ADC_CR2_EXTTRIG_BIT) = !!enable;
+}
+
+#endif
diff --git a/libmaple/stm32f1/rules.mk b/libmaple/stm32f1/rules.mk
index bdff00e..c0d6344 100644
--- a/libmaple/stm32f1/rules.mk
+++ b/libmaple/stm32f1/rules.mk
@@ -11,7 +11,8 @@ CFLAGS_$(d) = -I$(d) $(LIBMAPLE_PRIVATE_INCLUDES) $(LIBMAPLE_INCLUDES) -Wall -We
 sSRCS_$(d) := isrs_performance.S
 sSRCS_$(d) += vector_table_performance.S
 
-cSRCS_$(d) := bkp.c
+cSRCS_$(d) := adc.c
+cSRCS_$(d) += bkp.c
 cSRCS_$(d) += fsmc.c
 cSRCS_$(d) += gpio.c
 cSRCS_$(d) += rcc.c
diff --git a/libmaple/stm32f2/adc.c b/libmaple/stm32f2/adc.c
new file mode 100644
index 0000000..fbe1618
--- /dev/null
+++ b/libmaple/stm32f2/adc.c
@@ -0,0 +1,84 @@
+/******************************************************************************
+ * The MIT License
+ *
+ * Copyright (c) 2012 LeafLabs, LLC.
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy,
+ * modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *****************************************************************************/
+
+/**
+ * @file libmaple/stm32f2/include/series/adc.c
+ * @brief STM32F2 ADC header.
+ */
+
+#include <libmaple/adc.h>
+#include <libmaple/gpio.h>
+
+/*
+ * Devices
+ */
+
+static adc_dev adc1 = {
+    .regs   = ADC1_BASE,
+    .clk_id = RCC_ADC1,
+};
+/** ADC1 device. */
+const adc_dev *ADC1 = &adc1;
+
+static adc_dev adc2 = {
+    .regs   = ADC2_BASE,
+    .clk_id = RCC_ADC2,
+};
+/** ADC2 device. */
+const adc_dev *ADC2 = &adc2;
+
+adc_dev adc3 = {
+    .regs   = ADC3_BASE,
+    .clk_id = RCC_ADC3,
+};
+/** ADC3 device. */
+const adc_dev *ADC3 = &adc3;
+
+/*
+ * Common routines
+ */
+
+void adc_set_prescaler(adc_prescaler pre) {
+    uint32 ccr = ADC_COMMON_BASE->CCR;
+    ccr &= ~ADC_CCR_ADCPRE;
+    ccr |= (uint32)pre;
+    ADC_COMMON_BASE->CCR = ccr;
+}
+
+void adc_foreach(void (*fn)(const adc_dev*)) {
+    fn(ADC1);
+    fn(ADC2);
+    fn(ADC3);
+}
+
+void adc_gpio_cfg(gpio_dev *gdev, uint8 bit) {
+    gpio_set_modef(gdev, bit, GPIO_MODE_ANALOG, GPIO_MODEF_PUPD_NONE);
+}
+
+void adc_enable_single_swstart(const adc_dev *dev) {
+    adc_init(dev);
+    adc_enable(dev);
+}
diff --git a/libmaple/stm32f2/include/series/adc.h b/libmaple/stm32f2/include/series/adc.h
new file mode 100644
index 0000000..4f0cd6b
--- /dev/null
+++ b/libmaple/stm32f2/include/series/adc.h
@@ -0,0 +1,331 @@
+/******************************************************************************
+ * The MIT License
+ *
+ * Copyright (c) 2012 LeafLabs, LLC.
+ *
+ * Permission is hereby granted, free of charge, to any person
+ * obtaining a copy of this software and associated documentation
+ * files (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy,
+ * modify, merge, publish, distribute, sublicense, and/or sell copies
+ * of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *****************************************************************************/
+
+/**
+ * @file stm32f2/include/series/adc.h
+ * @author Marti Bolivar <mbolivar@leaflabs.com>,
+ * @brief STM32F2 ADC header.
+ */
+
+#ifndef _LIBMAPLE_STM32F2_ADC_H_
+#define _LIBMAPLE_STM32F2_ADC_H_
+
+#include <libmaple/libmaple_types.h>
+
+/*
+ * Devices
+ */
+
+extern const struct adc_dev *ADC1;
+extern const struct adc_dev *ADC2;
+extern const struct adc_dev *ADC3;
+
+/*
+ * Common register map
+ */
+
+/** ADC common register map type */
+typedef struct adc_common_reg_map {
+    __io uint32 CSR;            /**< Common status register */
+    __io uint32 CCR;            /**< Common control register */
+    __io uint32 CDR;            /**<
+                                 * @brief Common regular data register
+                                 *        for dual and triple modes */
+} adc_common_reg_map;
+
+/*
+ * Register map base pointers
+ */
+
+/** ADC1 register map base pointer. */
+#define ADC1_BASE       ((struct adc_reg_map*)0x40012000)
+/** ADC2 register map base pointer. */
+#define ADC2_BASE       ((struct adc_reg_map*)0x40012100)
+/** ADC3 register map base pointer. */
+#define ADC3_BASE       ((struct adc_reg_map*)0x40012200)
+/** ADC common register map base pointer. */
+#define ADC_COMMON_BASE ((struct adc_common_reg_map*)0x40012300)
+
+/*
+ * Register bit definitions
+ */
+
+/* Status register */
+
+/** Overrun bit. */
+#define ADC_SR_OVR_BIT                  5
+/** Overrun. */
+#define ADC_SR_OVR                      (1U << ADC_SR_OVR_BIT)
+
+/* Control register 1 */
+
+/** Overrun interrupt enable bit. */
+#define ADC_CR1_OVRIE_BIT               26
+
+/** Overrun interrupt error enable. */
+#define ADC_CR1_OVRIE                   (1U << ADC_CR1_OVRIE_BIT)
+/** Conversion resolution. */
+#define ADC_CR1_RES                     (0x3U << 24)
+/** Conversion resolution: 12 bit (at least 15 ADCCLK cycles). */
+#define ADC_CR1_RES_12BIT               (0x0U << 24)
+/** Conversion resolution: 10 bit (at least 13 ADCCLK cycles). */
+#define ADC_CR1_RES_10BIT               (0x1U << 24)
+/** Conversion resolution: 8 bit (at least 11 ADCCLK cycles). */
+#define ADC_CR1_RES_8BIT                (0x2U << 24)
+/** Conversion resolution: 6 bit (at least 9 ADCCLK cycles). */
+#define ADC_CR1_RES_6BIT                (0x3U << 24)
+
+/* Control register 2 */
+
+#define ADC_CR2_SWSTART_BIT             30
+#define ADC_CR2_JSWSTART_BIT            22
+#define ADC_CR2_ALIGN_BIT               11
+#define ADC_CR2_EOCS_BIT                10
+#define ADC_CR2_DDS_BIT                 9
+#define ADC_CR2_DMA_BIT                 8
+#define ADC_CR2_CONT_BIT                1
+#define ADC_CR2_ADON_BIT                0
+
+#define ADC_CR2_SWSTART                 (1U << ADC_CR2_SWSTART_BIT)
+#define ADC_CR2_EXTEN                   (0x3 << 28)
+#define ADC_CR2_EXTEN_DISABLED          (0x0 << 28)
+#define ADC_CR2_EXTEN_RISE              (0x1 << 28)
+#define ADC_CR2_EXTEN_FALL              (0x2 << 28)
+#define ADC_CR2_EXTEN_RISE_FALL         (0x3 << 28)
+#define ADC_CR2_EXTSEL                  (0xF << 24)
+#define ADC_CR2_EXTSEL_TIM1_CC1         (0x0 << 24)
+#define ADC_CR2_EXTSEL_TIM1_CC2         (0x1 << 24)
+#define ADC_CR2_EXTSEL_TIM1_CC3         (0x2 << 24)
+#define ADC_CR2_EXTSEL_TIM2_CC2         (0x3 << 24)
+#define ADC_CR2_EXTSEL_TIM2_CC3         (0x4 << 24)
+#define ADC_CR2_EXTSEL_TIM2_CC4         (0x5 << 24)
+#define ADC_CR2_EXTSEL_TIM1_TRGO        (0x6 << 24)
+#define ADC_CR2_EXTSEL_TIM3_CC1         (0x7 << 24)
+#define ADC_CR2_EXTSEL_TIM3_TRGO        (0x8 << 24)
+#define ADC_CR2_EXTSEL_TIM4_CC4         (0x9 << 24)
+#define ADC_CR2_EXTSEL_TIM5_CC1         (0xA << 24)
+#define ADC_CR2_EXTSEL_TIM5_CC2         (0xB << 24)
+#define ADC_CR2_EXTSEL_TIM5_CC3         (0xC << 24)
+#define ADC_CR2_EXTSEL_TIM8_CC1         (0xD << 24)
+#define ADC_CR2_EXTSEL_TIM8_TRGO        (0xE << 24)
+#define ADC_CR2_EXTSEL_TIM1_EXTI11      (0xF << 24)
+#define ADC_CR2_JSWSTART                (1U << ADC_CR2_JSWSTART_BIT)
+#define ADC_CR2_JEXTEN                  (0x3 << 20)
+#define ADC_CR2_JEXTEN_DISABLED         (0x0 << 20)
+#define ADC_CR2_JEXTEN_RISE             (0x1 << 20)
+#define ADC_CR2_JEXTEN_FALL             (0x2 << 20)
+#define ADC_CR2_JEXTEN_RISE_FALL        (0x3 << 20)
+#define ADC_CR2_JEXTSEL                 (0xF << 16)
+#define ADC_CR2_JEXTSEL_TIM1_CC4        (0x0 << 16)
+#define ADC_CR2_JEXTSEL_TIM1_TRGO       (0x1 << 16)
+#define ADC_CR2_JEXTSEL_TIM2_CC1        (0x2 << 16)
+#define ADC_CR2_JEXTSEL_TIM2_TRGO       (0x3 << 16)
+#define ADC_CR2_JEXTSEL_TIM3_CC2        (0x4 << 16)
+#define ADC_CR2_JEXTSEL_TIM3_CC4        (0x5 << 16)
+#define ADC_CR2_JEXTSEL_TIM4_CC1        (0x6 << 16)
+#define ADC_CR2_JEXTSEL_TIM4_CC2        (0x7 << 16)
+#define ADC_CR2_JEXTSEL_TIM4_CC3        (0x8 << 16)
+#define ADC_CR2_JEXTSEL_TIM4_TRGO       (0x9 << 16)
+#define ADC_CR2_JEXTSEL_TIM5_CC4        (0xA << 16)
+#define ADC_CR2_JEXTSEL_TIM5_TRGO       (0xB << 16)
+#define ADC_CR2_JEXTSEL_TIM8_CC2        (0xC << 16)
+#define ADC_CR2_JEXTSEL_TIM8_CC3        (0xD << 16)
+#define ADC_CR2_JEXTSEL_TIM8_CC4        (0xE << 16)
+#define ADC_CR2_JEXTSEL_TIM1_EXTI15     (0xF << 16)
+#define ADC_CR2_ALIGN                   (1U << ADC_CR2_ALIGN_BIT)
+#define ADC_CR2_ALIGN_RIGHT             (0U << ADC_CR2_ALIGN_BIT)
+#define ADC_CR2_ALIGN_LEFT              (1U << ADC_CR2_ALIGN_BIT)
+#define ADC_CR2_EOCS                    (1U << ADC_CR2_EOCS_BIT)
+#define ADC_CR2_EOCS_SEQUENCE           (0U << ADC_CR2_EOCS_BIT)
+#define ADC_CR2_EOCS_CONVERSION         (1U << ADC_CR2_EOCS_BIT)
+#define ADC_CR2_DDS                     (1U << ADC_CR2_DDS_BIT)
+#define ADC_CR2_DMA                     (1U << ADC_CR2_DMA_BIT)
+#define ADC_CR2_CONT                    (1U << ADC_CR2_CONT_BIT)
+#define ADC_CR2_ADON                    (1U << ADC_CR2_ADON_BIT)
+
+/* Common status register */
+
+#define ADC_CSR_OVR3_BIT                21
+#define ADC_CSR_STRT3_BIT               20
+#define ADC_CSR_JSTRT3_BIT              19
+#define ADC_CSR_JEOC3_BIT               18
+#define ADC_CSR_EOC3_BIT                17
+#define ADC_CSR_AWD3_BIT                16
+#define ADC_CSR_OVR2_BIT                13
+#define ADC_CSR_STRT2_BIT               12
+#define ADC_CSR_JSTRT2_BIT              11
+#define ADC_CSR_JEOC2_BIT               10
+#define ADC_CSR_EOC2_BIT                9
+#define ADC_CSR_AWD2_BIT                8
+#define ADC_CSR_OVR1_BIT                5
+#define ADC_CSR_STRT1_BIT               4
+#define ADC_CSR_JSTRT1_BIT              3
+#define ADC_CSR_JEOC1_BIT               2
+#define ADC_CSR_EOC1_BIT                1
+#define ADC_CSR_AWD1_BIT                0
+
+#define ADC_CSR_OVR3                    (1U << ADC_CSR_OVR3_BIT)
+#define ADC_CSR_STRT3                   (1U << ADC_CSR_STRT3_BIT)
+#define ADC_CSR_JSTRT3                  (1U << ADC_CSR_JSTRT3_BIT)
+#define ADC_CSR_JEOC3                   (1U << ADC_CSR_JEOC3_BIT)
+#define ADC_CSR_EOC3                    (1U << ADC_CSR_EOC3_BIT)
+#define ADC_CSR_AWD3                    (1U << ADC_CSR_AWD3_BIT)
+#define ADC_CSR_OVR2                    (1U << ADC_CSR_OVR2_BIT)
+#define ADC_CSR_STRT2                   (1U << ADC_CSR_STRT2_BIT)
+#define ADC_CSR_JSTRT2                  (1U << ADC_CSR_JSTRT2_BIT)
+#define ADC_CSR_JEOC2                   (1U << ADC_CSR_JEOC2_BIT)
+#define ADC_CSR_EOC2                    (1U << ADC_CSR_EOC2_BIT)
+#define ADC_CSR_AWD2                    (1U << ADC_CSR_AWD2_BIT)
+#define ADC_CSR_OVR1                    (1U << ADC_CSR_OVR1_BIT)
+#define ADC_CSR_STRT1                   (1U << ADC_CSR_STRT1_BIT)
+#define ADC_CSR_JSTRT1                  (1U << ADC_CSR_JSTRT1_BIT)
+#define ADC_CSR_JEOC1                   (1U << ADC_CSR_JEOC1_BIT)
+#define ADC_CSR_EOC1                    (1U << ADC_CSR_EOC1_BIT)
+#define ADC_CSR_AWD1                    (1U << ADC_CSR_AWD1_BIT)
+
+/* Common control register */
+
+#define ADC_CCR_TSVREFE_BIT             23
+#define ADC_CCR_VBATE_BIT               22
+#define ADC_CCR_DDS_BIT                 13
+
+#define ADC_CCR_TSVREFE                       (1U << ADC_CCR_TSVREFE_BIT)
+#define ADC_CCR_VBATE                         (1U << ADC_CCR_VBATE_BIT)
+#define ADC_CCR_ADCPRE                        (0x3 << 16)
+#define ADC_CCR_ADCPRE_PCLK2_DIV_2            (0x0 << 16)
+#define ADC_CCR_ADCPRE_PCLK2_DIV_4            (0x1 << 16)
+#define ADC_CCR_ADCPRE_PCLK2_DIV_6            (0x2 << 16)
+#define ADC_CCR_ADCPRE_PCLK2_DIV_8            (0x3 << 16)
+#define ADC_CCR_DMA                           (0x3 << 14)
+#define ADC_CCR_DMA_DIS                       (0x0 << 14)
+#define ADC_CCR_DMA_MODE_1                    (0x1 << 14)
+#define ADC_CCR_DMA_MODE_2                    (0x2 << 14)
+#define ADC_CCR_DMA_MODE_3                    (0x3 << 14)
+#define ADC_CCR_DDS                           (1U << ADC_CCR_DDS_BIT)
+#define ADC_CCR_DELAY                         (0xF << 8)
+#define ADC_CCR_DELAY_5                       (0x0 << 8)
+#define ADC_CCR_DELAY_6                       (0x1 << 8)
+#define ADC_CCR_DELAY_7                       (0x2 << 8)
+#define ADC_CCR_DELAY_8                       (0x3 << 8)
+#define ADC_CCR_DELAY_9                       (0x4 << 8)
+#define ADC_CCR_DELAY_10                      (0x5 << 8)
+#define ADC_CCR_DELAY_11                      (0x6 << 8)
+#define ADC_CCR_DELAY_12                      (0x7 << 8)
+#define ADC_CCR_DELAY_13                      (0x8 << 8)
+#define ADC_CCR_DELAY_14                      (0x9 << 8)
+#define ADC_CCR_DELAY_15                      (0xA << 8)
+#define ADC_CCR_DELAY_16                      (0xB << 8)
+#define ADC_CCR_DELAY_17                      (0xC << 8)
+#define ADC_CCR_DELAY_18                      (0xD << 8)
+#define ADC_CCR_DELAY_19                      (0xE << 8)
+#define ADC_CCR_DELAY_20                      (0xF << 8)
+/** Multi ADC mode selection. */
+#define ADC_CCR_MULTI                         0x1F
+/** All ADCs independent. */
+#define ADC_CCR_MULTI_INDEPENDENT             0x0
+/** Dual mode: combined regular simultaneous/injected simultaneous. */
+#define ADC_CCR_MULTI_DUAL_REG_SIM_INJ_SIM    0x1
+/** Dual mode: combined regular simultaneous/alternate trigger. */
+#define ADC_CCR_MULTI_DUAL_REG_SIM_ALT_TRIG   0x2
+/** Dual mode: injected simultaneous mode only. */
+#define ADC_CCR_MULTI_DUAL_INJ_SIM            0x5
+/** Dual mode: regular simultaneous mode only. */
+#define ADC_CCR_MULTI_DUAL_REG_SIM            0x6
+/** Dual mode: interleaved mode only. */
+#define ADC_CCR_MULTI_DUAL_INTER              0x7
+/** Dual mode: alternate trigger mode only. */
+#define ADC_CCR_MULTI_DUAL_ALT_TRIG           0x9
+/** Triple mode: combined regular simultaneous/injected simultaneous. */
+#define ADC_CCR_MULTI_TRIPLE_REG_SIM_INJ_SIM  0x10
+/** Triple mode: combined regular simultaneous/alternate trigger. */
+#define ADC_CCR_MULTI_TRIPLE_REG_SIM_ALT_TRIG 0x11
+/** Triple mode: injected simultaneous mode only. */
+#define ADC_CCR_MULTI_TRIPLE_INJ_SIM          0x12
+/** Triple mode: regular simultaneous mode only. */
+#define ADC_CCR_MULTI_TRIPLE_REG_SIM          0x15
+/** Triple mode: interleaved mode only. */
+#define ADC_CCR_MULTI_TRIPLE_INTER            0x17
+/** Triple mode: alternate trigger mode only. */
+#define ADC_CCR_MULTI_TRIPLE_ALT_TRIG         0x19
+
+/* Common regular data register for dual and triple modes */
+
+#define ADC_CDR_DATA2                   0xFFFF0000
+#define ADC_CDR_DATA1                   0xFFFF
+
+/*
+ * Other types
+ */
+
+/**
+ * @brief STM32F2 external event selectors for regular group
+ *        conversion.
+ * @see adc_set_extsel()
+ */
+typedef enum adc_extsel_event {
+    ADC_EXT_EV_TIM1_CC1    = ADC_CR2_EXTSEL_TIM1_CC1,
+    ADC_EXT_EV_TIM1_CC2    = ADC_CR2_EXTSEL_TIM1_CC2,
+    ADC_EXT_EV_TIM1_CC3    = ADC_CR2_EXTSEL_TIM1_CC3,
+    ADC_EXT_EV_TIM2_CC2    = ADC_CR2_EXTSEL_TIM2_CC2,
+    ADC_EXT_EV_TIM2_CC3    = ADC_CR2_EXTSEL_TIM2_CC3,
+    ADC_EXT_EV_TIM2_CC4    = ADC_CR2_EXTSEL_TIM2_CC4,
+    ADC_EXT_EV_TIM1_TRGO   = ADC_CR2_EXTSEL_TIM1_TRGO,
+    ADC_EXT_EV_TIM3_CC1    = ADC_CR2_EXTSEL_TIM3_CC1,
+    ADC_EXT_EV_TIM3_TRGO   = ADC_CR2_EXTSEL_TIM3_TRGO,
+    ADC_EXT_EV_TIM4_CC4    = ADC_CR2_EXTSEL_TIM4_CC4,
+    ADC_EXT_EV_TIM5_CC1    = ADC_CR2_EXTSEL_TIM5_CC1,
+    ADC_EXT_EV_TIM5_CC2    = ADC_CR2_EXTSEL_TIM5_CC2,
+    ADC_EXT_EV_TIM5_CC3    = ADC_CR2_EXTSEL_TIM5_CC3,
+    ADC_EXT_EV_TIM8_CC1    = ADC_CR2_EXTSEL_TIM8_CC1,
+    ADC_EXT_EV_TIM8_TRGO   = ADC_CR2_EXTSEL_TIM8_TRGO,
+    ADC_EXT_EV_TIM1_EXTI11 = ADC_CR2_EXTSEL_TIM1_EXTI11,
+} adc_extsel_event;
+
+/**
+ * @brief STM32F2 sample times, in ADC clock cycles.
+ */
+typedef enum adc_smp_rate {
+    ADC_SMPR_3,                 /**< 3 ADC cycles */
+    ADC_SMPR_15,                /**< 15 ADC cycles */
+    ADC_SMPR_28,                /**< 28 ADC cycles */
+    ADC_SMPR_56,                /**< 56 ADC cycles */
+    ADC_SMPR_84,                /**< 84 ADC cycles */
+    ADC_SMPR_112,               /**< 112 ADC cycles */
+    ADC_SMPR_144,               /**< 144 ADC cycles */
+    ADC_SMPR_480,               /**< 480 ADC cycles */
+} adc_smp_rate;
+
+/**
+ * @brief STM32F2 ADC prescalers, as divisors of PCLK2.
+ */
+typedef enum adc_prescaler {
+    ADC_PRE_PCLK2_DIV_2 = ADC_CCR_ADCPRE_PCLK2_DIV_2, /** PCLK2 divided by 2 */
+    ADC_PRE_PCLK2_DIV_4 = ADC_CCR_ADCPRE_PCLK2_DIV_4, /** PCLK2 divided by 4 */
+    ADC_PRE_PCLK2_DIV_6 = ADC_CCR_ADCPRE_PCLK2_DIV_6, /** PCLK2 divided by 6 */
+    ADC_PRE_PCLK2_DIV_8 = ADC_CCR_ADCPRE_PCLK2_DIV_8, /** PCLK2 divided by 8 */
+} adc_prescaler;
+
+#endif
diff --git a/libmaple/stm32f2/rules.mk b/libmaple/stm32f2/rules.mk
index a46f8d1..5951b94 100644
--- a/libmaple/stm32f2/rules.mk
+++ b/libmaple/stm32f2/rules.mk
@@ -11,6 +11,7 @@ CFLAGS_$(d) = -I$(d) $(LIBMAPLE_INCLUDES) $(LIBMAPLE_PRIVATE_INCLUDES) -Wall -We
 sSRCS_$(d) := isrs.S
 sSRCS_$(d) += vector_table.S
 
+cSRCS_$(d) := adc.c
 cSRCS_$(d) += fsmc.c
 cSRCS_$(d) += gpio.c
 cSRCS_$(d) += rcc.c
diff --git a/wirish/boards.cpp b/wirish/boards.cpp
index 04b359f..54807d3 100644
--- a/wirish/boards.cpp
+++ b/wirish/boards.cpp
@@ -54,6 +54,7 @@
 static void setup_flash(void);
 static void setup_clocks(void);
 static void setup_nvic(void);
+static void setup_adcs(void);
 
 /*
  * Exported functions
@@ -65,7 +66,7 @@ void init(void) {
     setup_nvic();
     systick_init(SYSTICK_RELOAD_VAL);
     wirish::priv::board_setup_gpio();
-    wirish::priv::board_setup_adc();
+    setup_adcs();
     wirish::priv::board_setup_timers();
     wirish::priv::board_setup_usb();
     boardInit();
@@ -124,7 +125,7 @@ static void setup_clocks(void) {
 
     // Configure AHBx, APBx, etc. prescalers and the main PLL.
     wirish::priv::board_setup_clock_prescalers();
-    rcc_configure_pll(&wirish::priv::board_pll_cfg);
+    rcc_configure_pll(&wirish::priv::w_board_pll_cfg);
 
     // Enable the PLL, and wait until it's ready.
     rcc_turn_on_clk(RCC_CLK_PLL);
@@ -146,3 +147,13 @@ static void setup_nvic(void) {
 #error "You must select a base address for the vector table."
 #endif
 }
+
+static void adc_default_config(const adc_dev *dev) {
+    adc_enable_single_swstart(dev);
+    adc_set_sample_rate(dev, wirish::priv::w_adc_smp);
+}
+
+static void setup_adcs(void) {
+    adc_set_prescaler(wirish::priv::w_adc_pre);
+    adc_foreach(adc_default_config);
+}
diff --git a/wirish/boards_private.h b/wirish/boards_private.h
index a4101c9..e32f298 100644
--- a/wirish/boards_private.h
+++ b/wirish/boards_private.h
@@ -28,11 +28,18 @@
  * @file wirish/boards_private.h
  * @author Marti Bolivar <mbolivar@leaflabs.com>
  * @brief Private board support header.
+ *
+ * This file declares chip-specific variables and functions which
+ * determine how init() behaves. It is not part of the public Wirish
+ * API, and can change without notice.
  */
 
 #ifndef _WIRISH_BOARDS_PRIVATE_H_
 #define _WIRISH_BOARDS_PRIVATE_H_
 
+#include <libmaple/rcc.h>
+#include <libmaple/adc.h>
+
 namespace wirish {
     namespace priv {
 
@@ -40,7 +47,9 @@ namespace wirish {
          * Chip-specific initialization data
          */
 
-        extern rcc_pll_cfg board_pll_cfg;
+        extern rcc_pll_cfg w_board_pll_cfg;
+        extern adc_prescaler w_adc_pre;
+        extern adc_smp_rate w_adc_smp;
 
         /*
          * Chip-specific initialization routines and helper functions.
@@ -49,7 +58,6 @@ namespace wirish {
         void board_reset_pll(void);
         void board_setup_clock_prescalers(void);
         void board_setup_gpio(void);
-        void board_setup_adc(void);
         void board_setup_timers(void);
         void board_setup_usb(void);
 
diff --git a/wirish/stm32f1/boards_setup.cpp b/wirish/stm32f1/boards_setup.cpp
index 4ee292a..8e16009 100644
--- a/wirish/stm32f1/boards_setup.cpp
+++ b/wirish/stm32f1/boards_setup.cpp
@@ -28,11 +28,15 @@
  * @file wirish/stm32f1/boards_setup.cpp
  * @author Marti Bolivar <mbolivar@leaflabs.com>
  * @brief STM32F1 chip setup.
+ *
+ * This file controls how init() behaves on the STM32F1. Be very
+ * careful when changing anything here. Many of these values depend
+ * upon each other.
  */
 
-#include <libmaple/rcc.h>
+#include "boards_private.h"
+
 #include <libmaple/gpio.h>
-#include <libmaple/adc.h>
 #include <libmaple/timer.h>
 #include <libmaple/usb_cdcacm.h>
 
@@ -45,12 +49,11 @@ namespace wirish {
     namespace priv {
 
         static stm32f1_rcc_pll_data pll_data = {RCC_PLLMUL_9};
-        rcc_pll_cfg board_pll_cfg = {RCC_PLLSRC_HSE, &pll_data};
+        rcc_pll_cfg w_board_pll_cfg = {RCC_PLLSRC_HSE, &pll_data};
+        adc_prescaler w_adc_pre = ADC_PRE_PCLK2_DIV_6;
+        adc_smp_rate w_adc_smp = ADC_SMPR_55_5;
 
-#if 0
-        static void config_adc(const adc_dev* dev);
         static void config_timer(timer_dev*);
-#endif
 
         void board_reset_pll(void) {
             // TODO
@@ -69,17 +72,8 @@ namespace wirish {
             afio_init();
         }
 
-        void board_setup_adc(void) {
-#if 0
-            rcc_set_prescaler(RCC_PRESCALER_ADC, RCC_ADCPRE_PCLK_DIV_6);
-            adc_foreach(config_adc);
-#endif
-        }
-
         void board_setup_timers(void) {
-#if 0
             timer_foreach(config_timer);
-#endif
         }
 
         void board_setup_usb(void) {
@@ -92,19 +86,8 @@ namespace wirish {
          * Auxiliary routines
          */
 
-#if 0
-        static void config_adc(const adc_dev *dev) {
-            adc_init(dev);
-
-            adc_set_extsel(dev, ADC_SWSTART);
-            adc_set_exttrig(dev, true);
-
-            adc_enable(dev);
-            adc_calibrate(dev);
-            adc_set_sample_rate(dev, ADC_SMPR_55_5);
-        }
-
         static void config_timer(timer_dev *dev) {
+#if 0
             timer_adv_reg_map *regs = (dev->regs).adv;
             const uint16 full_overflow = 0xFFFF;
             const uint16 half_duty = 0x8FFF;
@@ -135,7 +118,7 @@ namespace wirish {
             }
 
             timer_resume(dev);
-        }
 #endif
+        }
     }
 }
diff --git a/wirish/stm32f2/boards_setup.cpp b/wirish/stm32f2/boards_setup.cpp
index b3c690c..e1bf1fd 100644
--- a/wirish/stm32f2/boards_setup.cpp
+++ b/wirish/stm32f2/boards_setup.cpp
@@ -28,11 +28,18 @@
  * @file wirish/stm32f2/boards_setup.cpp
  * @author Marti Bolivar <mbolivar@leaflabs.com>
  * @brief STM32F2 chip setup.
+ *
+ * This file controls how init() behaves on the STM32F2. Be very
+ * careful when changing anything here. Many of these values depend
+ * upon each other.
  */
 
-#include <libmaple/rcc.h>
+#include "boards_private.h"
+
 #include <libmaple/gpio.h>
+#include <wirish/wirish_types.h>
 
+// PLL configuration for 25 MHz external oscillator --> 120 MHz SYSCLK.
 #define PLL_Q 5
 #define PLL_P 2
 #define PLL_N 240
@@ -41,7 +48,18 @@ static stm32f2_rcc_pll_data pll_data = {PLL_Q, PLL_P, PLL_N, PLL_M};
 
 namespace wirish {
     namespace priv {
-        rcc_pll_cfg board_pll_cfg = {RCC_PLLSRC_HSE, &pll_data};
+        // PLL clocked off of HSE, with above configuration data.
+        rcc_pll_cfg w_board_pll_cfg = {RCC_PLLSRC_HSE, &pll_data};
+        // As f_APB2 = 60 MHz (see board_setup_clock_prescalers),
+        // we need f_ADC = f_PCLK2 / 2 to get the (maximum)
+        // f_ADC = 30 MHz.
+        adc_prescaler w_adc_pre = ADC_PRE_PCLK2_DIV_2;
+        // With clocks as specified here (i.e. f_ADC = 30 MHz), this
+        // ADC sample rate allows for error less than 1/4 LSB with a
+        // 50 KOhm input impedance, assuming an internal sample and
+        // hold capacitance C_ADC at most 8.8 pF. See Equation 1 and
+        // Table 61 in the F2 datasheet for more details.
+        adc_smp_rate w_adc_smp = ADC_SMPR_144;
 
         void board_reset_pll(void) {
             // Set PLLCFGR to its reset value.
@@ -49,8 +67,13 @@ namespace wirish {
         }
 
         void board_setup_clock_prescalers(void) {
+            // With f_SYSCLK = 120 MHz (as determined by board_pll_cfg),
+            //
+            // f_AHB = f_SYSCLK / 1 = 120 MHz
             rcc_set_prescaler(RCC_PRESCALER_AHB, RCC_AHB_SYSCLK_DIV_1);
+            // f_APB1 = f_AHB / 4 = 30 MHz
             rcc_set_prescaler(RCC_PRESCALER_APB1, RCC_APB1_HCLK_DIV_4);
+            // f_APB2 = f_AHB / 2 = 60 MHz
             rcc_set_prescaler(RCC_PRESCALER_APB2, RCC_APB2_HCLK_DIV_2);
         }
 
@@ -58,10 +81,6 @@ namespace wirish {
             gpio_init_all();
         }
 
-        void board_setup_adc(void) {
-            // TODO
-        }
-
         void board_setup_timers(void) {
             // TODO
         }
@@ -72,4 +91,3 @@ namespace wirish {
 
     }
 }
-