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>

3 files changed, 366 insertions, 1 deletions

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