libmaple/spi: Fixups, move nonportable bits into libmaple/stm32f1.

Standard family support refactoring: add STM32F1 series spi.h, spi.c,
and move anything that won't port to STM32F2 there.

As part of a general effort to be cleaner, remove the dependency on
libmaple/util.h from libmaple/spi.h by not using BIT(). Also forward
declare struct gpio_dev for spi_gpio_cfg() to remove that include.

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

6 files changed, 231 insertions, 134 deletions

diff --git a/libmaple/include/libmaple/spi.h b/libmaple/include/libmaple/spi.h
index 7a665db..5b045a9 100644
--- a/libmaple/include/libmaple/spi.h
+++ b/libmaple/include/libmaple/spi.h
@@ -44,8 +44,7 @@ extern "C" {
 #include <libmaple/libmaple_types.h>
 #include <libmaple/rcc.h>
 #include <libmaple/nvic.h>
-#include <libmaple/gpio.h>
-#include <libmaple/util.h>
+#include <series/spi.h>
 
 /*
  * Register maps
@@ -64,13 +63,6 @@ typedef struct spi_reg_map {
     __io uint32 I2SPR;          /**< I2S prescaler register */
 } spi_reg_map;
 
-/** SPI1 register map base pointer */
-#define SPI1_BASE                       ((struct spi_reg_map*)0x40013000)
-/** SPI2 register map base pointer */
-#define SPI2_BASE                       ((struct spi_reg_map*)0x40003800)
-/** SPI3 register map base pointer */
-#define SPI3_BASE                       ((struct spi_reg_map*)0x40003C00)
-
 /*
  * Register bit definitions
  */
@@ -91,20 +83,20 @@ typedef struct spi_reg_map {
 #define SPI_CR1_CPOL_BIT                1
 #define SPI_CR1_CPHA_BIT                0
 
-#define SPI_CR1_BIDIMODE                BIT(SPI_CR1_BIDIMODE_BIT)
+#define SPI_CR1_BIDIMODE                (1U << SPI_CR1_BIDIMODE_BIT)
 #define SPI_CR1_BIDIMODE_2_LINE         (0x0 << SPI_CR1_BIDIMODE_BIT)
 #define SPI_CR1_BIDIMODE_1_LINE         (0x1 << SPI_CR1_BIDIMODE_BIT)
-#define SPI_CR1_BIDIOE                  BIT(SPI_CR1_BIDIOE_BIT)
-#define SPI_CR1_CRCEN                   BIT(SPI_CR1_CRCEN_BIT)
-#define SPI_CR1_CRCNEXT                 BIT(SPI_CR1_CRCNEXT_BIT)
-#define SPI_CR1_DFF                     BIT(SPI_CR1_DFF_BIT)
+#define SPI_CR1_BIDIOE                  (1U << SPI_CR1_BIDIOE_BIT)
+#define SPI_CR1_CRCEN                   (1U << SPI_CR1_CRCEN_BIT)
+#define SPI_CR1_CRCNEXT                 (1U << SPI_CR1_CRCNEXT_BIT)
+#define SPI_CR1_DFF                     (1U << SPI_CR1_DFF_BIT)
 #define SPI_CR1_DFF_8_BIT               (0x0 << SPI_CR1_DFF_BIT)
 #define SPI_CR1_DFF_16_BIT              (0x1 << SPI_CR1_DFF_BIT)
-#define SPI_CR1_RXONLY                  BIT(SPI_CR1_RXONLY_BIT)
-#define SPI_CR1_SSM                     BIT(SPI_CR1_SSM_BIT)
-#define SPI_CR1_SSI                     BIT(SPI_CR1_SSI_BIT)
-#define SPI_CR1_LSBFIRST                BIT(SPI_CR1_LSBFIRST_BIT)
-#define SPI_CR1_SPE                     BIT(SPI_CR1_SPE_BIT)
+#define SPI_CR1_RXONLY                  (1U << SPI_CR1_RXONLY_BIT)
+#define SPI_CR1_SSM                     (1U << SPI_CR1_SSM_BIT)
+#define SPI_CR1_SSI                     (1U << SPI_CR1_SSI_BIT)
+#define SPI_CR1_LSBFIRST                (1U << SPI_CR1_LSBFIRST_BIT)
+#define SPI_CR1_SPE                     (1U << SPI_CR1_SPE_BIT)
 #define SPI_CR1_BR                      (0x7 << 3)
 #define SPI_CR1_BR_PCLK_DIV_2           (0x0 << 3)
 #define SPI_CR1_BR_PCLK_DIV_4           (0x1 << 3)
@@ -114,17 +106,14 @@ typedef struct spi_reg_map {
 #define SPI_CR1_BR_PCLK_DIV_64          (0x5 << 3)
 #define SPI_CR1_BR_PCLK_DIV_128         (0x6 << 3)
 #define SPI_CR1_BR_PCLK_DIV_256         (0x7 << 3)
-#define SPI_CR1_MSTR                    BIT(SPI_CR1_MSTR_BIT)
-#define SPI_CR1_CPOL                    BIT(SPI_CR1_CPOL_BIT)
+#define SPI_CR1_MSTR                    (1U << SPI_CR1_MSTR_BIT)
+#define SPI_CR1_CPOL                    (1U << SPI_CR1_CPOL_BIT)
 #define SPI_CR1_CPOL_LOW                (0x0 << SPI_CR1_CPOL_BIT)
 #define SPI_CR1_CPOL_HIGH               (0x1 << SPI_CR1_CPOL_BIT)
-#define SPI_CR1_CPHA                    BIT(SPI_CR1_CPHA_BIT)
+#define SPI_CR1_CPHA                    (1U << SPI_CR1_CPHA_BIT)
 
 /* Control register 2 */
 
-/* RM0008-ism: SPI CR2 has "TXDMAEN" and "RXDMAEN" bits, while the
- * USARTs have CR3 "DMAR" and "DMAT" bits. */
-
 #define SPI_CR2_TXEIE_BIT               7
 #define SPI_CR2_RXNEIE_BIT              6
 #define SPI_CR2_ERRIE_BIT               5
@@ -132,12 +121,12 @@ typedef struct spi_reg_map {
 #define SPI_CR2_TXDMAEN_BIT             1
 #define SPI_CR2_RXDMAEN_BIT             0
 
-#define SPI_CR2_TXEIE                   BIT(SPI_CR2_TXEIE_BIT)
-#define SPI_CR2_RXNEIE                  BIT(SPI_CR2_RXNEIE_BIT)
-#define SPI_CR2_ERRIE                   BIT(SPI_CR2_ERRIE_BIT)
-#define SPI_CR2_SSOE                    BIT(SPI_CR2_SSOE_BIT)
-#define SPI_CR2_TXDMAEN                 BIT(SPI_CR2_TXDMAEN_BIT)
-#define SPI_CR2_RXDMAEN                 BIT(SPI_CR2_RXDMAEN_BIT)
+#define SPI_CR2_TXEIE                   (1U << SPI_CR2_TXEIE_BIT)
+#define SPI_CR2_RXNEIE                  (1U << SPI_CR2_RXNEIE_BIT)
+#define SPI_CR2_ERRIE                   (1U << SPI_CR2_ERRIE_BIT)
+#define SPI_CR2_SSOE                    (1U << SPI_CR2_SSOE_BIT)
+#define SPI_CR2_TXDMAEN                 (1U << SPI_CR2_TXDMAEN_BIT)
+#define SPI_CR2_RXDMAEN                 (1U << SPI_CR2_RXDMAEN_BIT)
 
 /* Status register */
 
@@ -150,37 +139,35 @@ typedef struct spi_reg_map {
 #define SPI_SR_TXE_BIT                  1
 #define SPI_SR_RXNE_BIT                 0
 
-#define SPI_SR_BSY                      BIT(SPI_SR_BSY_BIT)
-#define SPI_SR_OVR                      BIT(SPI_SR_OVR_BIT)
-#define SPI_SR_MODF                     BIT(SPI_SR_MODF_BIT)
-#define SPI_SR_CRCERR                   BIT(SPI_SR_CRCERR_BIT)
-#define SPI_SR_UDR                      BIT(SPI_SR_UDR_BIT)
-#define SPI_SR_CHSIDE                   BIT(SPI_SR_CHSIDE_BIT)
+#define SPI_SR_BSY                      (1U << SPI_SR_BSY_BIT)
+#define SPI_SR_OVR                      (1U << SPI_SR_OVR_BIT)
+#define SPI_SR_MODF                     (1U << SPI_SR_MODF_BIT)
+#define SPI_SR_CRCERR                   (1U << SPI_SR_CRCERR_BIT)
+#define SPI_SR_UDR                      (1U << SPI_SR_UDR_BIT)
+#define SPI_SR_CHSIDE                   (1U << SPI_SR_CHSIDE_BIT)
 #define SPI_SR_CHSIDE_LEFT              (0x0 << SPI_SR_CHSIDE_BIT)
 #define SPI_SR_CHSIDE_RIGHT             (0x1 << SPI_SR_CHSIDE_BIT)
-#define SPI_SR_TXE                      BIT(SPI_SR_TXE_BIT)
-#define SPI_SR_RXNE                     BIT(SPI_SR_RXNE_BIT)
+#define SPI_SR_TXE                      (1U << SPI_SR_TXE_BIT)
+#define SPI_SR_RXNE                     (1U << SPI_SR_RXNE_BIT)
 
 /* I2S configuration register */
 
-/* RM0008-ism: CR1 has "CPOL", I2SCFGR has "CKPOL". */
-
 #define SPI_I2SCFGR_I2SMOD_BIT          11
 #define SPI_I2SCFGR_I2SE_BIT            10
 #define SPI_I2SCFGR_PCMSYNC_BIT         7
 #define SPI_I2SCFGR_CKPOL_BIT           3
 #define SPI_I2SCFGR_CHLEN_BIT           0
 
-#define SPI_I2SCFGR_I2SMOD              BIT(SPI_I2SCFGR_I2SMOD_BIT)
+#define SPI_I2SCFGR_I2SMOD              (1U << SPI_I2SCFGR_I2SMOD_BIT)
 #define SPI_I2SCFGR_I2SMOD_SPI          (0x0 << SPI_I2SCFGR_I2SMOD_BIT)
 #define SPI_I2SCFGR_I2SMOD_I2S          (0x1 << SPI_I2SCFGR_I2SMOD_BIT)
-#define SPI_I2SCFGR_I2SE                BIT(SPI_I2SCFGR_I2SE_BIT)
+#define SPI_I2SCFGR_I2SE                (1U << SPI_I2SCFGR_I2SE_BIT)
 #define SPI_I2SCFGR_I2SCFG              (0x3 << 8)
 #define SPI_I2SCFGR_I2SCFG_SLAVE_TX     (0x0 << 8)
 #define SPI_I2SCFGR_I2SCFG_SLAVE_RX     (0x1 << 8)
 #define SPI_I2SCFGR_I2SCFG_MASTER_TX    (0x2 << 8)
 #define SPI_I2SCFGR_I2SCFG_MASTER_RX    (0x3 << 8)
-#define SPI_I2SCFGR_PCMSYNC             BIT(SPI_I2SCFGR_PCMSYNC_BIT)
+#define SPI_I2SCFGR_PCMSYNC             (1U << SPI_I2SCFGR_PCMSYNC_BIT)
 #define SPI_I2SCFGR_PCMSYNC_SHORT       (0x0 << SPI_I2SCFGR_PCMSYNC_BIT)
 #define SPI_I2SCFGR_PCMSYNC_LONG        (0x1 << SPI_I2SCFGR_PCMSYNC_BIT)
 #define SPI_I2SCFGR_I2SSTD              (0x3 << 4)
@@ -188,17 +175,26 @@ typedef struct spi_reg_map {
 #define SPI_I2SCFGR_I2SSTD_MSB          (0x1 << 4)
 #define SPI_I2SCFGR_I2SSTD_LSB          (0x2 << 4)
 #define SPI_I2SCFGR_I2SSTD_PCM          (0x3 << 4)
-#define SPI_I2SCFGR_CKPOL               BIT(SPI_I2SCFGR_CKPOL_BIT)
+#define SPI_I2SCFGR_CKPOL               (1U << SPI_I2SCFGR_CKPOL_BIT)
 #define SPI_I2SCFGR_CKPOL_LOW           (0x0 << SPI_I2SCFGR_CKPOL_BIT)
 #define SPI_I2SCFGR_CKPOL_HIGH          (0x1 << SPI_I2SCFGR_CKPOL_BIT)
 #define SPI_I2SCFGR_DATLEN              (0x3 << 1)
 #define SPI_I2SCFGR_DATLEN_16_BIT       (0x0 << 1)
 #define SPI_I2SCFGR_DATLEN_24_BIT       (0x1 << 1)
 #define SPI_I2SCFGR_DATLEN_32_BIT       (0x2 << 1)
-#define SPI_I2SCFGR_CHLEN               BIT(SPI_I2SCFGR_CHLEN_BIT)
+#define SPI_I2SCFGR_CHLEN               (1U << SPI_I2SCFGR_CHLEN_BIT)
 #define SPI_I2SCFGR_CHLEN_16_BIT        (0x0 << SPI_I2SCFGR_CHLEN_BIT)
 #define SPI_I2SCFGR_CHLEN_32_BIT        (0x1 << SPI_I2SCFGR_CHLEN_BIT)
 
+/* I2S prescaler register */
+
+#define SPI_I2SPR_MCKOE_BIT             9
+#define SPI_I2SPR_ODD_BIT               8
+
+#define SPI_I2SPR_MCKOE                 (1U << SPI_I2SPR_MCKOE_BIT)
+#define SPI_I2SPR_ODD                   (1U << SPI_I2SPR_ODD_BIT)
+#define SPI_I2SPR_I2SDIV                0xFF
+
 /*
  * Devices
  */
@@ -210,22 +206,28 @@ typedef struct spi_dev {
     nvic_irq_num irq_num;       /**< NVIC interrupt number */
 } spi_dev;
 
-extern spi_dev *SPI1;
-extern spi_dev *SPI2;
-#ifdef STM32_HIGH_DENSITY
-extern spi_dev *SPI3;
-#endif
-
 /*
  * SPI Convenience functions
  */
 
 void spi_init(spi_dev *dev);
 
+struct gpio_dev;
+/**
+ * @brief Configure GPIO bit modes for use as a SPI port's pins.
+ * @param as_master If true, configure bits for use as a bus master.
+ *                  Otherwise, configure bits for use as slave.
+ * @param nss_dev NSS pin's GPIO device
+ * @param comm_dev SCK, MISO, MOSI pins' GPIO device
+ * @param nss_bit NSS pin's GPIO bit on nss_dev
+ * @param sck_bit SCK pin's GPIO bit on comm_dev
+ * @param miso_bit MISO pin's GPIO bit on comm_dev
+ * @param mosi_bit MOSI pin's GPIO bit on comm_dev
+ */
 void spi_gpio_cfg(uint8 as_master,
-                  gpio_dev *nss_dev,
+                  struct gpio_dev *nss_dev,
                   uint8 nss_bit,
-                  gpio_dev *comm_dev,
+                  struct gpio_dev *comm_dev,
                   uint8 sck_bit,
                   uint8 miso_bit,
                   uint8 mosi_bit);
@@ -244,7 +246,7 @@ typedef enum spi_mode {
                     clock transition */
     SPI_MODE_2,  /**< Clock line idles high (1), data capture on first
                     clock transition. */
-    SPI_MODE_3   /**< Clock line idles high (1), data capture on
+    SPI_MODE_3,  /**< Clock line idles high (1), data capture on
                     second clock transition. */
 } spi_mode;
 
@@ -300,7 +302,11 @@ void spi_slave_enable(spi_dev *dev,
 
 uint32 spi_tx(spi_dev *dev, const void *buf, uint32 len);
 
-void spi_foreach(void (*fn)(spi_dev (*dev)));
+/**
+ * @brief Call a function on each SPI port
+ * @param fn Function to call.
+ */
+void spi_foreach(void (*fn)(spi_dev*));
 
 void spi_peripheral_enable(spi_dev *dev);
 void spi_peripheral_disable(spi_dev *dev);
diff --git a/libmaple/rules.mk b/libmaple/rules.mk
index 2f5e066..93716d2 100644
--- a/libmaple/rules.mk
+++ b/libmaple/rules.mk
@@ -18,6 +18,7 @@ cSRCS_$(d) += iwdg.c
 cSRCS_$(d) += nvic.c
 cSRCS_$(d) += pwr.c
 cSRCS_$(d) += rcc.c
+cSRCS_$(d) += spi.c
 cSRCS_$(d) += syscalls.c
 cSRCS_$(d) += systick.c
 cSRCS_$(d) += timer.c
@@ -29,7 +30,6 @@ cSRCS_$(d) += util.c
 # cSRCS_$(d) += dma.c
 # cSRCS_$(d) += exti.c
 # cSRCS_$(d) += i2c.c
-# cSRCS_$(d) += spi.c
 
 sSRCS_$(d) := exc.S
 
diff --git a/libmaple/spi.c b/libmaple/spi.c
index 00b7ce2..194a82e 100644
--- a/libmaple/spi.c
+++ b/libmaple/spi.c
@@ -38,36 +38,6 @@
 static void spi_reconfigure(spi_dev *dev, uint32 cr1_config);
 
 /*
- * SPI devices
- */
-
-static spi_dev spi1 = {
-    .regs     = SPI1_BASE,
-    .clk_id   = RCC_SPI1,
-    .irq_num  = NVIC_SPI1,
-};
-/** SPI device 1 */
-spi_dev *SPI1 = &spi1;
-
-static spi_dev spi2 = {
-    .regs     = SPI2_BASE,
-    .clk_id   = RCC_SPI2,
-    .irq_num  = NVIC_SPI2,
-};
-/** SPI device 2 */
-spi_dev *SPI2 = &spi2;
-
-#ifdef STM32_HIGH_DENSITY
-static spi_dev spi3 = {
-    .regs     = SPI3_BASE,
-    .clk_id   = RCC_SPI3,
-    .irq_num  = NVIC_SPI3,
-};
-/** SPI device 3 */
-spi_dev *SPI3 = &spi3;
-#endif
-
-/*
  * SPI convenience routines
  */
 
@@ -81,37 +51,6 @@ void spi_init(spi_dev *dev) {
 }
 
 /**
- * @brief Configure GPIO bit modes for use as a SPI port's pins.
- * @param as_master If true, configure bits for use as a bus master.
- *                  Otherwise, configure bits for use as slave.
- * @param nss_dev NSS pin's GPIO device
- * @param comm_dev SCK, MISO, MOSI pins' GPIO device
- * @param nss_bit NSS pin's GPIO bit on nss_dev
- * @param sck_bit SCK pin's GPIO bit on comm_dev
- * @param miso_bit MISO pin's GPIO bit on comm_dev
- * @param mosi_bit MOSI pin's GPIO bit on comm_dev
- */
-void spi_gpio_cfg(uint8 as_master,
-                  gpio_dev *nss_dev,
-                  uint8 nss_bit,
-                  gpio_dev *comm_dev,
-                  uint8 sck_bit,
-                  uint8 miso_bit,
-                  uint8 mosi_bit) {
-    if (as_master) {
-        gpio_set_mode(nss_dev, nss_bit, GPIO_AF_OUTPUT_PP);
-        gpio_set_mode(comm_dev, sck_bit, GPIO_AF_OUTPUT_PP);
-        gpio_set_mode(comm_dev, miso_bit, GPIO_INPUT_FLOATING);
-        gpio_set_mode(comm_dev, mosi_bit, GPIO_AF_OUTPUT_PP);
-    } else {
-        gpio_set_mode(nss_dev, nss_bit, GPIO_INPUT_FLOATING);
-        gpio_set_mode(comm_dev, sck_bit, GPIO_INPUT_FLOATING);
-        gpio_set_mode(comm_dev, miso_bit, GPIO_AF_OUTPUT_PP);
-        gpio_set_mode(comm_dev, mosi_bit, GPIO_INPUT_FLOATING);
-    }
-}
-
-/**
  * @brief Configure and enable a SPI device as bus master.
  *
  * The device's peripheral will be disabled before being reconfigured.
@@ -166,18 +105,6 @@ uint32 spi_tx(spi_dev *dev, const void *buf, uint32 len) {
 }
 
 /**
- * @brief Call a function on each SPI port
- * @param fn Function to call.
- */
-void spi_foreach(void (*fn)(spi_dev*)) {
-    fn(SPI1);
-    fn(SPI2);
-#ifdef STM32_HIGH_DENSITY
-    fn(SPI3);
-#endif
-}
-
-/**
  * @brief Enable a SPI peripheral
  * @param dev Device to enable
  */
@@ -235,7 +162,3 @@ static void spi_reconfigure(spi_dev *dev, uint32 cr1_config) {
     dev->regs->CR1 = cr1_config;
     spi_peripheral_enable(dev);
 }
-
-/*
- * IRQ handlers (TODO)
- */
diff --git a/libmaple/stm32f1/include/series/spi.h b/libmaple/stm32f1/include/series/spi.h
new file mode 100644
index 0000000..167df0c
--- /dev/null
+++ b/libmaple/stm32f1/include/series/spi.h
@@ -0,0 +1,70 @@
+/******************************************************************************
+ * The MIT License
+ *
+ * Copyright (c) 2011, 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/spi.h
+ * @author Marti Bolivar <mbolivar@leaflabs.com>
+ * @brief STM32F1 SPI/I2S series header.
+ */
+
+#ifndef _LIBMAPLE_STM32F1_SPI_H_
+#define _LIBMAPLE_STM32F1_SPI_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * Register map base pointers
+ */
+
+struct spi_reg_map;
+
+/** SPI1 register map base pointer */
+#define SPI1_BASE                       ((struct spi_reg_map*)0x40013000)
+/** SPI2 register map base pointer */
+#define SPI2_BASE                       ((struct spi_reg_map*)0x40003800)
+/** SPI3 register map base pointer */
+#define SPI3_BASE                       ((struct spi_reg_map*)0x40003C00)
+
+/*
+ * Device pointers
+ */
+
+struct spi_dev;
+
+extern struct spi_dev *SPI1;
+extern struct spi_dev *SPI2;
+#if defined(STM32_HIGH_DENSITY) || defined(STM32_XL_DENSITY)
+extern struct spi_dev *SPI3;
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/libmaple/stm32f1/rules.mk b/libmaple/stm32f1/rules.mk
index 03fddb3..52ceea6 100644
--- a/libmaple/stm32f1/rules.mk
+++ b/libmaple/stm32f1/rules.mk
@@ -16,6 +16,7 @@ cSRCS_$(d) += bkp.c
 cSRCS_$(d) += fsmc.c
 cSRCS_$(d) += gpio.c
 cSRCS_$(d) += rcc.c
+cSRCS_$(d) += spi.c
 cSRCS_$(d) += timer.c
 cSRCS_$(d) += usart.c
 
diff --git a/libmaple/stm32f1/spi.c b/libmaple/stm32f1/spi.c
new file mode 100644
index 0000000..b860918
--- /dev/null
+++ b/libmaple/stm32f1/spi.c
@@ -0,0 +1,97 @@
+/******************************************************************************
+ * The MIT License
+ *
+ * Copyright (c) 2011, 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/spi.c
+ * @author Marti Bolivar <mbolivar@leaflabs.com>
+ * @brief STM32F1 SPI/I2S support.
+ */
+
+#include <libmaple/spi.h>
+#include <libmaple/gpio.h>
+
+/*
+ * Devices
+ */
+
+static spi_dev spi1 = {
+    .regs     = SPI1_BASE,
+    .clk_id   = RCC_SPI1,
+    .irq_num  = NVIC_SPI1,
+};
+/** SPI device 1 */
+spi_dev *SPI1 = &spi1;
+
+static spi_dev spi2 = {
+    .regs     = SPI2_BASE,
+    .clk_id   = RCC_SPI2,
+    .irq_num  = NVIC_SPI2,
+};
+/** SPI device 2 */
+spi_dev *SPI2 = &spi2;
+
+#if defined(STM32_HIGH_DENSITY) || defined(STM32_XL_DENSITY)
+static spi_dev spi3 = {
+    .regs     = SPI3_BASE,
+    .clk_id   = RCC_SPI3,
+    .irq_num  = NVIC_SPI3,
+};
+/** SPI device 3 */
+spi_dev *SPI3 = &spi3;
+#endif
+
+/*
+ * Routines
+ */
+
+void spi_gpio_cfg(uint8 as_master,
+                  gpio_dev *nss_dev,
+                  uint8 nss_bit,
+                  gpio_dev *comm_dev,
+                  uint8 sck_bit,
+                  uint8 miso_bit,
+                  uint8 mosi_bit) {
+    if (as_master) {
+        gpio_set_mode(nss_dev, nss_bit, GPIO_AF_OUTPUT_PP);
+        gpio_set_mode(comm_dev, sck_bit, GPIO_AF_OUTPUT_PP);
+        gpio_set_mode(comm_dev, miso_bit, GPIO_INPUT_FLOATING);
+        gpio_set_mode(comm_dev, mosi_bit, GPIO_AF_OUTPUT_PP);
+    } else {
+        gpio_set_mode(nss_dev, nss_bit, GPIO_INPUT_FLOATING);
+        gpio_set_mode(comm_dev, sck_bit, GPIO_INPUT_FLOATING);
+        gpio_set_mode(comm_dev, miso_bit, GPIO_AF_OUTPUT_PP);
+        gpio_set_mode(comm_dev, mosi_bit, GPIO_INPUT_FLOATING);
+    }
+}
+
+void spi_foreach(void (*fn)(spi_dev*)) {
+    fn(SPI1);
+    fn(SPI2);
+#if defined(STM32_HIGH_DENSITY) || defined(STM32_XL_DENSITY)
+    fn(SPI3);
+#endif
+}