-/*
- * Copyright © 2010 Keith Packard <keithp@keithp.com>
- *
- * 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; version 2 of the License.
- *
- * 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, write to the Free Software Foundation, Inc.,
- * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
- */
-
-#include "ao.h"
-
-/* Shared mutex to protect SPI bus, must cover the entire
- * operation, from CS low to CS high. This means that any SPI
- * user must protect the SPI bus with this mutex
- */
-__xdata uint8_t ao_spi_mutex;
-__xdata uint8_t ao_spi_dma_in_done;
-__xdata uint8_t ao_spi_dma_out_done;
-
-uint8_t ao_spi_dma_out_id;
-uint8_t ao_spi_dma_in_id;
-
-static __xdata uint8_t ao_spi_const;
-
-/* Send bytes over SPI.
- *
- * This sets up two DMA engines, one writing the data and another reading
- * bytes coming back. We use the bytes coming back to tell when the transfer
- * is complete, as the transmit register is double buffered and hence signals
- * completion one byte before the transfer is actually complete
- */
-void
-ao_spi_send_bus(void __xdata *block, uint16_t len) __reentrant
-{
-#if !AO_SPI_SLAVE
- ao_dma_set_transfer(ao_spi_dma_in_id,
- &U0DBUFXADDR,
- &ao_spi_const,
- len,
- DMA_CFG0_WORDSIZE_8 |
- DMA_CFG0_TMODE_SINGLE |
- DMA_CFG0_TRIGGER_URX0,
- DMA_CFG1_SRCINC_0 |
- DMA_CFG1_DESTINC_0 |
- DMA_CFG1_PRIORITY_NORMAL);
-#endif
- ao_dma_set_transfer(ao_spi_dma_out_id,
- block,
- &U0DBUFXADDR,
- len,
- DMA_CFG0_WORDSIZE_8 |
- DMA_CFG0_TMODE_SINGLE |
- DMA_CFG0_TRIGGER_UTX0,
- DMA_CFG1_SRCINC_1 |
- DMA_CFG1_DESTINC_0 |
- DMA_CFG1_PRIORITY_NORMAL);
-
-#if !AO_SPI_SLAVE
- ao_dma_start(ao_spi_dma_in_id);
-#endif
- ao_dma_start(ao_spi_dma_out_id);
- ao_dma_trigger(ao_spi_dma_out_id);
-#if AO_SPI_SLAVE
- __critical while (!ao_spi_dma_out_done)
- ao_sleep(&ao_spi_dma_out_done);
-#else
- __critical while (!ao_spi_dma_in_done)
- ao_sleep(&ao_spi_dma_in_done);
-#endif
-}
-
-/* Receive bytes over SPI.
- *
- * This sets up tow DMA engines, one reading the data and another
- * writing constant values to the SPI transmitter as that is what
- * clocks the data coming in.
- */
-void
-ao_spi_recv_bus(void __xdata *block, uint16_t len) __reentrant
-{
- ao_dma_set_transfer(ao_spi_dma_in_id,
- &U0DBUFXADDR,
- block,
- len,
- DMA_CFG0_WORDSIZE_8 |
- DMA_CFG0_TMODE_SINGLE |
- DMA_CFG0_TRIGGER_URX0,
- DMA_CFG1_SRCINC_0 |
- DMA_CFG1_DESTINC_1 |
- DMA_CFG1_PRIORITY_NORMAL);
-
- ao_spi_const = 0xff;
-
- ao_dma_set_transfer(ao_spi_dma_out_id,
- &ao_spi_const,
- &U0DBUFXADDR,
- len,
- DMA_CFG0_WORDSIZE_8 |
- DMA_CFG0_TMODE_SINGLE |
- DMA_CFG0_TRIGGER_UTX0,
- DMA_CFG1_SRCINC_0 |
- DMA_CFG1_DESTINC_0 |
- DMA_CFG1_PRIORITY_NORMAL);
-
- ao_dma_start(ao_spi_dma_in_id);
- ao_dma_start(ao_spi_dma_out_id);
- ao_dma_trigger(ao_spi_dma_out_id);
- __critical while (!ao_spi_dma_in_done)
- ao_sleep(&ao_spi_dma_in_done);
-}
-
-/*
- * Initialize USART0 for SPI using config alt 2
- *
- * MO P1_5
- * MI P1_4
- * CLK P1_3
- * CSS P1_2
- *
- * Chip select is the responsibility of the caller in master mode
- */
-
-#if AO_SPI_SLAVE
-#define CSS (1 << 2)
-#define UxCSR_DIRECTION UxCSR_SLAVE
-#else
-#define CSS 0
-#define UxCSR_DIRECTION UxCSR_MASTER
-#endif
-
-void
-ao_spi_init(void)
-{
- /* Set up the USART pin assignment */
- PERCFG = (PERCFG & ~PERCFG_U0CFG_ALT_MASK) | PERCFG_U0CFG_ALT_2;
-
- /* Ensure that USART0 takes precidence over USART1 for pins that
- * they share
- */
- P2SEL = (P2SEL & ~P2SEL_PRI3P1_MASK) | P2SEL_PRI3P1_USART0;
-
- /* Make the SPI pins be controlled by the USART peripheral */
- P1SEL |= ((1 << 5) | (1 << 4) | (1 << 3) | CSS);
-
- /* Set up OUT DMA */
- ao_spi_dma_out_id = ao_dma_alloc(&ao_spi_dma_out_done);
-
- /* Set up IN DMA */
- ao_spi_dma_in_id = ao_dma_alloc(&ao_spi_dma_in_done);
-
- /* Set up the USART.
- *
- * SPI master mode
- */
- U0CSR = (UxCSR_MODE_SPI | UxCSR_RE | UxCSR_DIRECTION);
-
- /* Set the baud rate and signal parameters
- *
- * The cc1111 is limited to a 24/8 MHz SPI clock.
- * Every peripheral I've ever seen goes faster than that,
- * so set the clock to 3MHz (BAUD_E 17, BAUD_M 0)
- */
- U0BAUD = 0;
- U0GCR = (UxGCR_CPOL_NEGATIVE |
- UxGCR_CPHA_FIRST_EDGE |
- UxGCR_ORDER_MSB |
- (17 << UxGCR_BAUD_E_SHIFT));
-}