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-rw-r--r--libmaple/spi.c333
-rw-r--r--libmaple/spi.h495
2 files changed, 629 insertions, 199 deletions
diff --git a/libmaple/spi.c b/libmaple/spi.c
index 7bdc18a..2fbc2ac 100644
--- a/libmaple/spi.c
+++ b/libmaple/spi.c
@@ -3,161 +3,250 @@
*
* 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
+ * 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 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.
+ * 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.
*****************************************************************************/
/**
- * @brief libmaple serial peripheral interface (SPI) definitions
- *
- * Initial implementation for the SPI interface.
- *
- * This driver implements only the bare essentials of a polling driver at the
- * moment. Master mode only, 8-bit data frames, and polling.
- *
- * The caller is responsible for controlling the chip select line.
- *
- * TODO: interrupt based driver, DMA.
- *
+ * @file spi.c
+ * @author Marti Bolivar <mbolivar@leaflabs.com>
+ * @brief Serial Peripheral Interface (SPI) support.
+ * Currently, there is no Integrated Interchip Sound (I2S) support.
*/
-#include "libmaple.h"
-#include "gpio.h"
-#include "rcc.h"
#include "spi.h"
+#include "bitband.h"
-typedef struct spi_dev {
- SPI *base;
- gpio_dev *gpio_d;
- uint8 sck_pin;
- uint8 miso_pin;
- uint8 mosi_pin;
-} spi_dev;
-
-spi_dev spi_dev1 = {
- .base = (SPI*)SPI1_BASE,
- .gpio_d = NULL,
- .sck_pin = 5,
- .miso_pin = 6,
- .mosi_pin = 7
-};
+/*
+ * SPI devices
+ */
-spi_dev spi_dev2 = {
- .base = (SPI*)SPI2_BASE,
- .gpio_d = NULL,
- .sck_pin = 13,
- .miso_pin = 14,
- .mosi_pin = 15
+static spi_dev spi1 = {
+ .regs = SPI1_BASE,
+ .clk_id = RCC_SPI1,
+ .irq_num = NVIC_SPI1,
};
+spi_dev *SPI1 = &spi1;
-static void spi_gpio_cfg(const spi_dev *dev);
+static spi_dev spi2 = {
+ .regs = SPI2_BASE,
+ .clk_id = RCC_SPI2,
+ .irq_num = NVIC_SPI2,
+};
+spi_dev *SPI2 = &spi2;
-/**
- * @brief Initialize a spi peripheral
- * @param spi_num which spi to turn on, SPI1 or SPI2?
- * @param prescale prescale factor on the input clock.
- * @param endian data frame format (LSBFIRST?)
- * @param mode SPI mode number
- */
-void spi_init(uint32 spi_num,
- uint32 prescale,
- uint32 endian,
- uint32 mode) {
- ASSERT(spi_num == 1 || spi_num == 2);
- ASSERT(mode < 4);
-
- SPI *spi;
- uint32 cr1 = 0;
-
- switch (spi_num) {
- case 1:
- /* limit to 18 mhz max speed */
- ASSERT(prescale != CR1_BR_PRESCALE_2);
- spi = (SPI*)SPI1_BASE;
- rcc_clk_enable(RCC_SPI1);
- spi_dev1.gpio_d = GPIOA;
- spi_gpio_cfg(&spi_dev1);
- break;
- case 2:
- spi = (SPI*)SPI2_BASE;
- rcc_clk_enable(RCC_SPI2);
- spi_dev1.gpio_d = GPIOB,
- spi_gpio_cfg(&spi_dev2);
- break;
- }
+#ifdef STM32_HIGH_DENSITY
+static spi_dev spi3 = {
+ .regs = SPI3_BASE,
+ .clk_id = RCC_SPI3,
+ .irq_num = NVIC_SPI3,
+};
+spi_dev *SPI3 = &spi3;
+#endif
- cr1 = prescale | endian | mode | CR1_MSTR | CR1_SSI | CR1_SSM;
- spi->CR1 = cr1;
+/*
+ * SPI convenience routines
+ */
- /* Peripheral enable */
- spi->CR1 |= CR1_SPE;
+/**
+ * @brief Initialize and reset a SPI device.
+ * @param dev Device to initialize and reset.
+ */
+void spi_init(spi_dev *dev) {
+ rcc_clk_enable(dev->clk_id);
+ rcc_reset_dev(dev->clk_id);
}
/**
- * @brief SPI synchronous 8-bit write, blocking.
- * @param spi_num which spi to send on
- * @return data shifted back from the slave
+ * @brief Configure GPIO bit modes for use as a SPI bus master's pins.
+ * @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
*/
-uint8 spi_tx_byte(uint32 spi_num, uint8 data) {
- SPI *spi;
+void spi_master_gpio_cfg(gpio_dev *nss_dev,
+ gpio_dev *comm_dev,
+ uint8 nss_bit,
+ uint8 sck_bit,
+ uint8 miso_bit,
+ uint8 mosi_bit) {
+ 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);
+}
- spi = (spi_num == 1) ? (SPI*)SPI1_BASE : (SPI*)SPI2_BASE;
+/**
+ * @brief Configure GPIO bit modes for use as a SPI bus slave's pins.
+ * @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_slave_gpio_cfg(gpio_dev *nss_dev,
+ gpio_dev *comm_dev,
+ uint8 nss_bit,
+ uint8 sck_bit,
+ uint8 miso_bit,
+ uint8 mosi_bit) {
+ 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);
+}
- while (!(spi->SR & SR_TXE))
- ;
+static void spi_reconfigure(spi_dev *dev, uint32 cr1_config);
- spi->DR = data;
+/**
+ * @brief Configure and enable a SPI device as bus master.
+ *
+ * The device's peripheral will be disabled before being reconfigured.
+ *
+ * @param dev Device to configure as bus master
+ * @param baud Bus baud rate
+ * @param mode SPI mode
+ * @param flags Logical OR of spi_cfg_flag values.
+ * @see spi_cfg_flag
+ */
+void spi_master_enable(spi_dev *dev,
+ spi_baud_rate baud,
+ spi_mode mode,
+ uint32 flags) {
+ spi_reconfigure(dev, baud | flags | SPI_CR1_MSTR | mode);
+}
- while (!(spi->SR & SR_RXNE))
- ;
+/**
+ * @brief Configure and enable a SPI device as a bus slave.
+ *
+ * The device's peripheral will be disabled before being reconfigured.
+ *
+ * @param dev Device to configure as a bus slave
+ * @param mode SPI mode
+ * @param flags Logical OR of spi_cfg_flag values.
+ * @see spi_cfg_flag
+ */
+void spi_slave_enable(spi_dev *dev, spi_mode mode, uint32 flags) {
+ spi_reconfigure(dev, flags | mode);
+}
- return spi->DR;
+/**
+ * @brief Nonblocking SPI transmit.
+ * @param dev SPI port to use for transmission
+ * @param buf Buffer to transmit. The sizeof buf's elements are
+ * inferred from the dev's data frame format (i.e., are
+ * correctly treated as 8-bit or 16-bit quantities).
+ * @param len Maximum number of elements to transmit.
+ * @return Number of elements transmitted.
+ */
+uint32 spi_tx(spi_dev *dev, const void *buf, uint32 len) {
+ spi_reg_map *regs = dev->regs;
+ uint32 txed = 0;
+ if (spi_dff(dev) == SPI_DFF_16_BIT) {
+ const uint8 *buf8 = (const uint8*)buf;
+ while ((regs->SR & SPI_SR_TXE) && (txed < len)) {
+ regs->DR = buf8[txed++];
+ }
+ } else {
+ const uint16 *buf16 = (const uint16*)buf;
+ while ((regs->SR & SPI_SR_TXE) && (txed < len)) {
+ regs->DR = buf16[txed++];
+ }
+ }
+ return txed;
}
-uint8 spi_tx(uint32 spi_num, uint8 *buf, uint32 len) {
- SPI *spi;
- uint32 i = 0;
- uint8 rc;
+/**
+ * @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
+}
- ASSERT(spi_num == 1 || spi_num == 2);
- spi = (spi_num == 1) ? (SPI*)SPI1_BASE : (SPI*)SPI2_BASE;
+/**
+ * @brief Enable a SPI peripheral
+ * @param dev Device to enable
+ */
+void spi_peripheral_enable(spi_dev *dev) {
+ bb_peri_set_bit(&dev->regs->CR1, SPI_CR1_SPE_BIT, 1);
+}
- if (!len) {
- return 0;
- }
+/**
+ * @brief Disable a SPI peripheral
+ * @param dev Device to disable
+ */
+void spi_peripheral_disable(spi_dev *dev) {
+ bb_peri_set_bit(&dev->regs->CR1, SPI_CR1_SPE_BIT, 0);
+}
- while (i < len) {
- while (!(spi->SR & SR_TXE))
- ;
+/**
+ * @brief Enable DMA requests whenever the transmit buffer is empty
+ * @param dev SPI device on which to enable TX DMA requests
+ */
+void spi_tx_dma_enable(spi_dev *dev) {
+ bb_peri_set_bit(&dev->regs->CR2, SPI_CR2_TXDMAEN_BIT, 1);
+}
- spi->DR = buf[i];
+/**
+ * @brief Disable DMA requests whenever the transmit buffer is empty
+ * @param dev SPI device on which to disable TX DMA requests
+ */
+void spi_tx_dma_disable(spi_dev *dev) {
+ bb_peri_set_bit(&dev->regs->CR2, SPI_CR2_TXDMAEN_BIT, 0);
+}
- while (!(spi->SR & SR_RXNE))
- ;
+/**
+ * @brief Enable DMA requests whenever the receive buffer is empty
+ * @param dev SPI device on which to enable RX DMA requests
+ */
+void spi_rx_dma_enable(spi_dev *dev) {
+ bb_peri_set_bit(&dev->regs->CR2, SPI_CR2_RXDMAEN_BIT, 1);
+}
- rc = spi->DR;
- i++;
- }
- return rc;
+/**
+ * @brief Disable DMA requests whenever the receive buffer is empty
+ * @param dev SPI device on which to disable RX DMA requests
+ */
+void spi_rx_dma_disable(spi_dev *dev) {
+ bb_peri_set_bit(&dev->regs->CR2, SPI_CR2_RXDMAEN_BIT, 0);
}
-static void spi_gpio_cfg(const spi_dev *dev) {
- gpio_set_mode(dev->gpio_d, dev->sck_pin, GPIO_AF_OUTPUT_PP);
- gpio_set_mode(dev->gpio_d, dev->miso_pin, GPIO_AF_OUTPUT_PP);
- gpio_set_mode(dev->gpio_d, dev->mosi_pin, GPIO_AF_OUTPUT_PP);
+/*
+ * SPI auxiliary routines
+ */
+
+static void spi_reconfigure(spi_dev *dev, uint32 cr1_config) {
+ spi_irq_disable(dev, SPI_INTERRUPTS_ALL);
+ spi_peripheral_disable(dev);
+ dev->regs->CR1 = cr1_config;
+ spi_peripheral_enable(dev);
}
+
+/*
+ * IRQ handlers (TODO)
+ */
diff --git a/libmaple/spi.h b/libmaple/spi.h
index 5ebf52d..e2820dd 100644
--- a/libmaple/spi.h
+++ b/libmaple/spi.h
@@ -24,99 +24,440 @@
/**
* @file spi.h
- * @brief libmaple serial peripheral interface (SPI) prototypes and
- * declarations
+ * @author Marti Bolivar <mbolivar@leaflabs.com>
+ * @brief Serial Peripheral Interface (SPI) and Integrated
+ * Interchip Sound (I2S) peripheral support.
+ *
+ * I2S support is currently limited to register maps and bit definitions.
*/
#ifndef _SPI_H_
#define _SPI_H_
#include "libmaple_types.h"
+#include "rcc.h"
+#include "nvic.h"
+#include "gpio.h"
#include "util.h"
#ifdef __cplusplus
extern "C" {
#endif
-/* peripheral addresses */
-#define SPI1_BASE 0x40013000
-#define SPI2_BASE 0x40003800
-#define SPI3_BASE 0x40003C00
-
-/* baud rate prescaler bits */
-#define CR1_BR 0x00000038
-#define CR1_BR_PRESCALE_2 0x00000000
-#define CR1_BR_PRESCALE_4 0x00000008
-#define CR1_BR_PRESCALE_8 0x00000010
-#define CR1_BR_PRESCALE_16 0x00000018
-#define CR1_BR_PRESCALE_32 0x00000020
-#define CR1_BR_PRESCALE_64 0x00000028
-#define CR1_BR_PRESCALE_128 0x00000030
-#define CR1_BR_PRESCALE_256 0x00000038
-
-#define CR1_LSBFIRST BIT(7) // data frame format
-#define CR1_MSTR BIT(2) // master selection
-#define CR1_SSM BIT(9) // software slave management
-#define CR1_SSI BIT(8) // internal slave select
-#define CR1_SPE BIT(6) // peripheral enable
-
-/* Status register bits */
-#define SR_RXNE BIT(0) // rx buffer not empty
-#define SR_TXE BIT(1) // transmit buffer empty
-#define SR_BSY BIT(7) // busy flag
-
-typedef struct SPI {
- __io uint16 CR1;
- uint16 pad0;
- __io uint8 CR2;
- uint8 pad1[3];
- __io uint8 SR;
- uint8 pad2[3];
- __io uint16 DR;
- uint16 pad3;
- __io uint16 CRCPR;
- uint16 pad4;
- __io uint16 RXCRCR;
- uint16 pad5;
- __io uint16 TXCRCR;
- uint16 pad6;
-} SPI;
-
-enum {
- SPI_MSBFIRST = 0,
- SPI_LSBFIRST = BIT(7),
-};
-
-enum {
- SPI_PRESCALE_2 = (0x0 << 3),
- SPI_PRESCALE_4 = (0x1 << 3),
- SPI_PRESCALE_8 = (0x2 << 3),
- SPI_PRESCALE_16 = (0x3 << 3),
- SPI_PRESCALE_32 = (0x4 << 3),
- SPI_PRESCALE_64 = (0x5 << 3),
- SPI_PRESCALE_128 = (0x6 << 3),
- SPI_PRESCALE_256 = (0x7 << 3)
-};
-
-void spi_init(uint32 spi_num,
- uint32 prescale,
- uint32 endian,
- uint32 mode);
-uint8 spi_tx_byte(uint32 spi_num, uint8 data);
-uint8 spi_tx(uint32 spi_num, uint8 *buf, uint32 len);
-
-static inline uint8 spi_rx(uint32 spi_num) {
- SPI *spi;
-
- ASSERT(spi_num == 1 || spi_num == 2);
- spi = (spi_num == 1) ? (SPI*)SPI1_BASE : (SPI*)SPI2_BASE;
-
- return spi->DR;
+/*
+ * Register maps
+ */
+
+/** SPI register map type. */
+typedef struct spi_reg_map {
+ __io uint32 CR1; /**< Control register 1 */
+ __io uint32 CR2; /**< Control register 2 */
+ __io uint32 SR; /**< Status register */
+ __io uint32 DR; /**< Data register */
+ __io uint32 CRCPR; /**< CRC polynomial register */
+ __io uint32 RXCRCR; /**< RX CRC register */
+ __io uint32 TXCRCR; /**< TX CRC register */
+ __io uint32 I2SCFGR; /**< I2S configuration register */
+ __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
+ */
+
+/* Control register 1 */
+
+#define SPI_CR1_BIDIMODE_BIT 15
+#define SPI_CR1_BIDIOE_BIT 14
+#define SPI_CR1_CRCEN_BIT 13
+#define SPI_CR1_CRCNEXT_BIT 12
+#define SPI_CR1_DFF_BIT 11
+#define SPI_CR1_RXONLY_BIT 10
+#define SPI_CR1_SSM_BIT 9
+#define SPI_CR1_SSI_BIT 8
+#define SPI_CR1_LSBFIRST_BIT 7
+#define SPI_CR1_SPE_BIT 6
+#define SPI_CR1_MSTR_BIT 2
+#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_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_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_BR (0x7 << 3)
+#define SPI_CR1_BR_PCLK_DIV_2 (0x0 << 3)
+#define SPI_CR1_BR_PCLK_DIV_4 (0x1 << 3)
+#define SPI_CR1_BR_PCLK_DIV_8 (0x2 << 3)
+#define SPI_CR1_BR_PCLK_DIV_16 (0x3 << 3)
+#define SPI_CR1_BR_PCLK_DIV_32 (0x4 << 3)
+#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_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)
+
+/* 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
+#define SPI_CR2_SSOE_BIT 2
+#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)
+
+/* Status register */
+
+#define SPI_SR_BSY_BIT 7
+#define SPI_SR_OVR_BIT 6
+#define SPI_SR_MODF_BIT 5
+#define SPI_SR_CRCERR_BIT 4
+#define SPI_SR_UDR_BIT 3
+#define SPI_SR_CHSIDE_BIT 2
+#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_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)
+
+/* 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_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_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_SHORT (0x0 << SPI_I2SCFGR_PCMSYNC_BIT)
+#define SPI_I2SCFGR_PCMSYNC_LONG (0x1 << SPI_I2SCFGR_PCMSYNC_BIT)
+#define SPI_I2SCFGR_I2SSTD (0x3 << 4)
+#define SPI_I2SCFGR_I2SSTD_PHILLIPS (0x0 << 4)
+#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_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_16_BIT (0x0 << SPI_I2SCFGR_CHLEN_BIT)
+#define SPI_I2SCFGR_CHLEN_32_BIT (0x1 << SPI_I2SCFGR_CHLEN_BIT)
+
+/*
+ * Devices
+ */
+
+/** SPI device type */
+typedef struct spi_dev {
+ spi_reg_map *regs;
+ rcc_clk_id clk_id;
+ nvic_irq_num irq_num;
+} spi_dev;
+
+/** SPI device 1 */
+extern spi_dev *SPI1;
+/** SPI device 2 */
+extern spi_dev *SPI2;
+#ifdef STM32_HIGH_DENSITY
+/** SPI device 3 */
+extern spi_dev *SPI3;
+#endif
+
+/*
+ * SPI Convenience functions
+ */
+
+void spi_init(spi_dev *dev);
+
+void spi_master_gpio_cfg(gpio_dev *nss_dev,
+ gpio_dev *comm_dev,
+ uint8 nss_bit,
+ uint8 sck_bit,
+ uint8 miso_bit,
+ uint8 mosi_bit);
+
+void spi_slave_gpio_cfg(gpio_dev *nss_dev,
+ gpio_dev *comm_dev,
+ uint8 nss_bit,
+ uint8 sck_bit,
+ uint8 miso_bit,
+ uint8 mosi_bit);
+
+/**
+ * @brief SPI mode configuration.
+ *
+ * Determines a combination of clock polarity (CPOL), which determines
+ * idle state of the clock line, and clock phase (CPHA), which
+ * determines which clock edge triggers data capture.
+ */
+typedef enum {
+ SPI_MODE_0, /**< Clock line idles low (0), data capture on first
+ clock transition. */
+ SPI_MODE_1, /**< Clock line idles low (0), data capture on second
+ 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
+ second clock transition. */
+} spi_mode;
+
+/**
+ * @brief SPI baud rate configuration, as a divisor of f_PCLK, the
+ * PCLK clock frequency.
+ */
+typedef enum {
+ SPI_BAUD_PCLK_DIV_2 = SPI_CR1_BR_PCLK_DIV_2, /**< f_PCLK/2 */
+ SPI_BAUD_PCLK_DIV_4 = SPI_CR1_BR_PCLK_DIV_4, /**< f_PCLK/4 */
+ SPI_BAUD_PCLK_DIV_8 = SPI_CR1_BR_PCLK_DIV_8, /**< f_PCLK/8 */
+ SPI_BAUD_PCLK_DIV_16 = SPI_CR1_BR_PCLK_DIV_16, /**< f_PCLK/16 */
+ SPI_BAUD_PCLK_DIV_32 = SPI_CR1_BR_PCLK_DIV_32, /**< f_PCLK/32 */
+ SPI_BAUD_PCLK_DIV_64 = SPI_CR1_BR_PCLK_DIV_64, /**< f_PCLK/64 */
+ SPI_BAUD_PCLK_DIV_128 = SPI_CR1_BR_PCLK_DIV_128, /**< f_PCLK/128 */
+ SPI_BAUD_PCLK_DIV_256 = SPI_CR1_BR_PCLK_DIV_256, /**< f_PCLK/256 */
+} spi_baud_rate;
+
+/**
+ * @brief SPI initialization flags.
+ * @see spi_master_enable()
+ * @see spi_slave_enable()
+ */
+typedef enum {
+ SPI_BIDIMODE = SPI_CR1_BIDIMODE, /**< Bidirectional mode enable */
+ SPI_BIDIOE = SPI_CR1_BIDIOE, /**< Output enable in bidirectional
+ mode */
+ SPI_CRCEN = SPI_CR1_CRCEN, /**< Cyclic redundancy check (CRC)
+ enable */
+ SPI_DFF_8_BIT = SPI_CR1_DFF_8_BIT, /**< 8-bit data frame format (this is
+ the default) */
+ SPI_DFF_16_BIT = SPI_CR1_DFF_16_BIT, /**< 16-bit data frame format */
+ SPI_RX_ONLY = SPI_CR1_RXONLY, /**< Receive only */
+ SPI_SW_SLAVE = SPI_CR1_SSM, /**< Software slave management */
+ SPI_SOFT_SS = SPI_CR1_SSI, /**< Software (internal) slave
+ select. This flag only has an
+ effect when used in combination
+ with SPI_SW_SLAVE. */
+ SPI_FRAME_LSB = SPI_CR1_LSBFIRST, /**< LSB-first (little-endian) frame
+ format */
+ SPI_FRAME_MSB = 0, /**< MSB-first (big-endian) frame
+ format (this is the default) */
+} spi_cfg_flag;
+
+void spi_master_enable(spi_dev *dev,
+ spi_baud_rate baud,
+ spi_mode mode,
+ uint32 flags);
+
+void spi_slave_enable(spi_dev *dev,
+ spi_mode mode,
+ uint32 flags);
+
+uint32 spi_tx(spi_dev *dev, const void *buf, uint32 len);
+
+void spi_foreach(void (*fn)(spi_dev (*dev)));
+
+void spi_peripheral_enable(spi_dev *dev);
+void spi_peripheral_disable(spi_dev *dev);
+
+void spi_tx_dma_enable(spi_dev *dev);
+void spi_tx_dma_disable(spi_dev *dev);
+
+void spi_rx_dma_enable(spi_dev *dev);
+void spi_rx_dma_disable(spi_dev *dev);
+
+/**
+ * @brief Determine if a SPI peripheral is enabled.
+ * @parm dev SPI device
+ * @return True, if and only if dev's peripheral is enabled.
+ */
+static inline uint8 spi_is_enabled(spi_dev *dev) {
+ return dev->regs->CR1 & SPI_CR1_SPE_BIT;
+}
+
+/**
+ * @brief Disable all SPI peripherals
+ */
+static inline void spi_peripheral_disable_all(void) {
+ spi_foreach(spi_peripheral_disable);
+}
+
+/** Available SPI interrupts */
+typedef enum {
+ SPI_TXE_INTERRUPT = SPI_CR2_TXEIE, /**< TX buffer empty interrupt */
+ SPI_RXNE_INTERRUPT = SPI_CR2_RXNEIE, /**< RX buffer not empty interrupt */
+ SPI_ERR_INTERRUPT = SPI_CR2_ERRIE /**<
+ * Error interrupt (CRC, overrun,
+ * and mode fault errors for SPI;
+ * underrun, overrun errors for I2S)
+ */
+} spi_interrupt;
+
+/**
+ * @brief Mask for all spi_interrupt values
+ * @see spi_interrupt
+ */
+#define SPI_INTERRUPTS_ALL (SPI_TXE_INTERRUPT | \
+ SPI_RXNE_INTERRUPT | \
+ SPI_ERR_INTERRUPT)
+
+/**
+ * @brief Enable SPI interrupt requests
+ * @param dev SPI device
+ * @param interrupt_flags Bitwise OR of spi_interrupt values to enable
+ * @see spi_interrupt
+ */
+static inline void spi_irq_enable(spi_dev *dev, uint32 interrupt_flags) {
+ dev->regs->CR2 |= interrupt_flags;
+ nvic_irq_enable(dev->irq_num);
+}
+
+/**
+ * @brief Disable SPI interrupt requests
+ * @param dev SPI device
+ * @param interrupt_flags Bitwise OR of spi_interrupt values to disable
+ * @see spi_interrupt
+ */
+static inline void spi_irq_disable(spi_dev *dev, uint32 interrupt_flags) {
+ dev->regs->CR2 &= ~interrupt_flags;
+}
+
+/**
+ * @brief Get the data frame format flags with which a SPI port is
+ * configured.
+ * @param dev SPI device whose data frame format to get.
+ * @return SPI_DFF_8_BIT, if dev has an 8-bit data frame format.
+ * Otherwise, SPI_DFF_16_BIT.
+ */
+static inline spi_cfg_flag spi_dff(spi_dev *dev) {
+ return ((dev->regs->CR1 & SPI_CR1_DFF) == SPI_CR1_DFF_8_BIT ?
+ SPI_DFF_8_BIT :
+ SPI_DFF_16_BIT);
+}
+
+/**
+ * @brief Determine whether the device's peripheral receive (RX)
+ * register is empty.
+ * @param dev SPI device
+ * @return true, iff dev's RX register is empty.
+ */
+static inline uint8 spi_is_rx_nonempty(spi_dev *dev) {
+ return dev->regs->SR & SPI_SR_RXNE;
+}
+
+/**
+ * @brief Retrieve the contents of the device's peripheral receive
+ * (RX) register.
+ *
+ * You may only call this function when the RX register is nonempty.
+ * Calling this function clears the contents of the RX register.
+ *
+ * @param dev SPI device
+ * @return Contents of dev's peripheral RX register
+ * @see spi_is_rx_reg_nonempty()
+ */
+static inline uint16 spi_rx_reg(spi_dev *dev) {
+ return (uint16)dev->regs->DR;
+}
+
+/**
+ * @brief Determine whether the device's peripheral transmit (TX)
+ * register is empty.
+ * @param dev SPI device
+ * @return true, iff dev's TX register is empty.
+ */
+static inline uint8 spi_is_tx_empty(spi_dev *dev) {
+ return dev->regs->SR & SPI_SR_TXE;
+}
+
+/**
+ * @brief Load a value into the device's peripheral transmit (TX) register.
+ *
+ * You may only call this function when the TX register is empty.
+ * Calling this function loads val into the peripheral's TX register.
+ * If the device is properly configured, this will initiate a
+ * transmission, the completion of which will cause the TX register to
+ * be empty again.
+ *
+ * @param dev SPI device
+ * @param val Value to load into the TX register. If the SPI data
+ * frame format is 8 bit, the value must be right-aligned.
+ * @see spi_is_tx_reg_empty()
+ * @see spi_init()
+ * @see spi_master_enable()
+ * @see spi_slave_enable()
+ */
+static inline void spi_tx_reg(spi_dev *dev, uint16 val) {
+ dev->regs->DR = val;
+}
+
+/**
+ * @brief Determine whether the device's peripheral busy (SPI_SR_BSY)
+ * flag is set.
+ * @param dev SPI device
+ * @return true, iff dev's BSY flag is set.
+ */
+static inline uint8 spi_is_busy(spi_dev *dev) {
+ return dev->regs->SR & SPI_SR_BSY;
}
+/*
+ * I2S convenience functions (TODO)
+ */
+
#ifdef __cplusplus
}
#endif
#endif
-