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-rw-r--r--lib/stm32/spi.c290
1 files changed, 290 insertions, 0 deletions
diff --git a/lib/stm32/spi.c b/lib/stm32/spi.c
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--- /dev/null
+++ b/lib/stm32/spi.c
@@ -0,0 +1,290 @@
+/*
+ * This file is part of the libopenstm32 project.
+ *
+ * Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <libopenstm32/spi.h>
+
+/*
+ * SPI and I2S code.
+ *
+ * Examples:
+ * spi_init_master(SPI1, 1000000, SPI_CR1_CPOL_CLK_TO_0_WHEN_IDLE,
+ * SPI_CR1_CPHA_CLK_TRANSITION_1, SPI_CR1_DFF_8BIT,
+ * SPI_CR1_LSBFIRST);
+ * spi_write(SPI1, 0x55); // 8-bit write
+ * spi_write(SPI1, 0xaa88); // 16-bit write
+ * reg8 = spi_read(SPI1); // 8-bit read
+ * reg16 = spi_read(SPI1); // 16-bit read
+ */
+
+int spi_init_master(u32 spi, u32 br, u32 cpol, u32 cpha, u32 dff, u32 lsbfirst)
+{
+ u32 reg32 = 0;
+
+ reg32 |= SPI_CR1_MSTR; /* Configure SPI as master. */
+
+ reg32 |= br; /* Set BAUD rate bits. */
+ reg32 |= cpol; /* Set CPOL value. */
+ reg32 |= cpha; /* Set CPHA value. */
+ reg32 |= dff; /* Set data format (8 or 16 bits). */
+ reg32 |= lsbfirst; /* Set frame format (LSB- or MSB-first). */
+
+ /* TODO: NSS pin handling. */
+
+ SPI_CR1(spi) = reg32;
+
+ return 0; /* TODO */
+}
+
+/* TODO: Error handling? */
+void spi_enable(u32 spi)
+{
+ u32 reg32;
+
+ reg32 = SPI_CR1(spi);
+ reg32 |= SPI_CR1_SPE; /* Enable SPI. */
+ SPI_CR1(spi) = reg32;
+}
+
+/* TODO: Error handling? */
+void spi_disable(u32 spi)
+{
+ u32 reg32;
+
+ /* TODO: Follow procedure from section 23.3.8 in the techref manual. */
+ reg32 = SPI_CR1(spi);
+ reg32 &= ~(SPI_CR1_SPE); /* Disable SPI. */
+ SPI_CR1(spi) = reg32;
+}
+
+void spi_write(u32 spi, u16 data)
+{
+ /* Write data (8 or 16 bits, depending on DFF) into DR. */
+ SPI_DR(spi) = data;
+}
+
+void spi_send(u32 spi, u16 data)
+{
+ /* Write data (8 or 16 bits, depending on DFF) into DR. */
+ SPI_DR(spi) = data;
+
+ /* wait for transfer finished */
+ while (SPI_SR(spi) & SPI_SR_BSY )
+ {
+ }
+}
+
+u16 spi_read(u32 spi)
+{
+ /* Read the data (8 or 16 bits, depending on DFF bit) from DR. */
+ return SPI_DR(spi);
+}
+
+void spi_set_bidirectional_mode(u32 spi)
+{
+ SPI_CR1(spi) |= SPI_CR1_BIDIMODE;
+}
+
+void spi_set_unidirectional_mode(u32 spi)
+{
+ SPI_CR1(spi) &= ~SPI_CR1_BIDIMODE;
+}
+
+void spi_set_bidirectional_receive_only_mode(u32 spi)
+{
+ SPI_CR1(spi) |= SPI_CR1_BIDIMODE;
+ SPI_CR1(spi) &= ~SPI_CR1_BIDIOE;
+}
+
+void spi_set_bidirectional_transmit_only_mode(u32 spi)
+{
+ SPI_CR1(spi) |= SPI_CR1_BIDIMODE;
+ SPI_CR1(spi) |= SPI_CR1_BIDIOE;
+}
+
+void spi_enable_crc(u32 spi)
+{
+ SPI_CR1(spi) |= SPI_CR1_CRCEN;
+}
+
+void spi_disable_crc(u32 spi)
+{
+ SPI_CR1(spi) &= ~SPI_CR1_CRCEN;
+}
+
+void spi_set_next_tx_from_buffer(u32 spi)
+{
+ SPI_CR1(spi) &= ~SPI_CR1_CRCNEXT;
+}
+
+void spi_set_next_tx_from_crc(u32 spi)
+{
+ SPI_CR1(spi) |= SPI_CR1_CRCNEXT;
+}
+
+void spi_set_dff_8bit(u32 spi)
+{
+ SPI_CR1(spi) &= ~SPI_CR1_DFF;
+}
+
+void spi_set_dff_16bit(u32 spi)
+{
+ SPI_CR1(spi) |= SPI_CR1_DFF;
+}
+
+void spi_set_full_duplex_mode(u32 spi)
+{
+ SPI_CR1(spi) &= ~SPI_CR1_RXONLY;
+}
+
+void spi_set_receive_only_mode(u32 spi)
+{
+ SPI_CR1(spi) |= SPI_CR1_RXONLY;
+}
+
+void spi_disable_software_slave_management(u32 spi)
+{
+ SPI_CR1(spi) &= ~SPI_CR1_SSM;
+}
+
+void spi_enable_software_slave_management(u32 spi)
+{
+ SPI_CR1(spi) |= SPI_CR1_SSM;
+}
+
+void spi_set_nss_high(u32 spi)
+{
+ SPI_CR1(spi) |= SPI_CR1_SSI;
+}
+
+void spi_set_nss_low(u32 spi)
+{
+ SPI_CR1(spi) &= ~SPI_CR1_SSI;
+}
+
+void spi_send_lsb_first(u32 spi)
+{
+ SPI_CR1(spi) |= SPI_CR1_LSBFIRST;
+}
+
+void spi_send_msb_first(u32 spi)
+{
+ SPI_CR1(spi) &= ~SPI_CR1_LSBFIRST;
+}
+
+void spi_set_baudrate_prescaler(u32 spi, u8 baudrate)
+{
+ u32 reg32;
+
+ if (baudrate > 7)
+ return;
+
+ reg32 = ( SPI_CR1(spi) & 0xffc7 ); /* clear bits [5:3] */
+ reg32 |= (baudrate << 3);
+ SPI_CR1(spi) = reg32;
+}
+
+void spi_set_master_mode(u32 spi)
+{
+ SPI_CR1(spi) |= SPI_CR1_MSTR;
+}
+
+void spi_set_slave_mode(u32 spi)
+{
+ SPI_CR1(spi) &= ~SPI_CR1_MSTR;
+}
+
+void spi_set_clock_polarity_1(u32 spi)
+{
+ SPI_CR1(spi) |= SPI_CR1_CPOL;
+}
+
+void spi_set_clock_polarity_0(u32 spi)
+{
+ SPI_CR1(spi) &= ~SPI_CR1_CPOL;
+}
+
+void spi_set_clock_phase_1(u32 spi)
+{
+ SPI_CR1(spi) |= SPI_CR1_CPHA;
+}
+
+void spi_set_clock_phase_0(u32 spi)
+{
+ SPI_CR1(spi) &= ~SPI_CR1_CPHA;
+}
+
+void spi_enable_tx_buffer_empty_interrupt(u32 spi)
+{
+ SPI_CR2(spi) |= SPI_CR2_TXEIE;
+}
+
+void spi_disable_tx_buffer_empty_interrupt(u32 spi)
+{
+ SPI_CR2(spi) &= ~SPI_CR2_TXEIE;
+}
+
+void spi_enable_rx_buffer_not_empty_interrupt(u32 spi)
+{
+ SPI_CR2(spi) |= SPI_CR2_RXNEIE;
+}
+
+void spi_disable_rx_buffer_not_empty_interrupt(u32 spi)
+{
+ SPI_CR2(spi) &= ~SPI_CR2_RXNEIE;
+}
+
+void spi_enable_error_interrupt(u32 spi)
+{
+ SPI_CR2(spi) |= SPI_CR2_ERRIE;
+}
+
+void spi_disable_error_interrupt(u32 spi)
+{
+ SPI_CR2(spi) &= ~SPI_CR2_ERRIE;
+}
+
+void spi_enable_ss_output(u32 spi)
+{
+ SPI_CR2(spi) |= SPI_CR2_SSOE;
+}
+
+void spi_disable_ss_output(u32 spi)
+{
+ SPI_CR2(spi) &= ~SPI_CR2_SSOE;
+}
+
+void spi_enable_tx_dma(u32 spi)
+{
+ SPI_CR2(spi) |= SPI_CR2_TXDMAEN;
+}
+
+void spi_disable_tx_dma(u32 spi)
+{
+ SPI_CR2(spi) &= ~SPI_CR2_TXDMAEN;
+}
+
+void spi_enable_rx_dma(u32 spi)
+{
+ SPI_CR2(spi) |= SPI_CR2_RXDMAEN;
+}
+
+void spi_disable_rx_dma(u32 spi)
+{
+ SPI_CR2(spi) &= ~SPI_CR2_RXDMAEN;
+}