mirror of https://github.com/hak5/openwrt-owl.git
449 lines
11 KiB
C
449 lines
11 KiB
C
/*******************************************************************************
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*
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* CNS3XXX SPI controller driver (master mode only)
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*
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* Copyright (c) 2008 Cavium Networks
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* Copyright 2011 Gateworks Corporation
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* Chris Lang <clang@gateworks.com>
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*
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* This file is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License, Version 2, as
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* published by the Free Software Foundation.
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*
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* This file is distributed in the hope that it will be useful,
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* but AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
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* NONINFRINGEMENT. See the GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this file; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA or
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* visit http://www.gnu.org/licenses/.
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*
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* This file may also be available under a different license from Cavium.
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* Contact Cavium Networks for more information
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*
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******************************************************************************/
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#include <linux/init.h>
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#include <linux/spinlock.h>
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#include <linux/workqueue.h>
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#include <linux/interrupt.h>
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#include <linux/delay.h>
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#include <linux/errno.h>
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#include <linux/err.h>
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#include <linux/clk.h>
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#include <linux/platform_device.h>
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#include <linux/spi/spi.h>
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#include <linux/spi/spi_bitbang.h>
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#include <linux/mtd/partitions.h>
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#include <linux/dma-mapping.h>
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#include <linux/slab.h>
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#include <asm/io.h>
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#include <asm/memory.h>
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#include <asm/dma.h>
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#include <asm/delay.h>
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#include <linux/module.h>
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/*
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* define access macros
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*/
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#define SPI_MEM_MAP_VALUE(reg_offset) (*((u32 volatile *)(hw->base + reg_offset)))
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#define SPI_CONFIGURATION_REG SPI_MEM_MAP_VALUE(0x00)
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#define SPI_SERVICE_STATUS_REG SPI_MEM_MAP_VALUE(0x04)
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#define SPI_BIT_RATE_CONTROL_REG SPI_MEM_MAP_VALUE(0x08)
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#define SPI_TRANSMIT_CONTROL_REG SPI_MEM_MAP_VALUE(0x0C)
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#define SPI_TRANSMIT_BUFFER_REG SPI_MEM_MAP_VALUE(0x10)
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#define SPI_RECEIVE_CONTROL_REG SPI_MEM_MAP_VALUE(0x14)
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#define SPI_RECEIVE_BUFFER_REG SPI_MEM_MAP_VALUE(0x18)
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#define SPI_FIFO_TRANSMIT_CONFIG_REG SPI_MEM_MAP_VALUE(0x1C)
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#define SPI_FIFO_TRANSMIT_CONTROL_REG SPI_MEM_MAP_VALUE(0x20)
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#define SPI_FIFO_RECEIVE_CONFIG_REG SPI_MEM_MAP_VALUE(0x24)
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#define SPI_INTERRUPT_STATUS_REG SPI_MEM_MAP_VALUE(0x28)
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#define SPI_INTERRUPT_ENABLE_REG SPI_MEM_MAP_VALUE(0x2C)
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#define SPI_TRANSMIT_BUFFER_REG_ADDR (CNS3XXX_SSP_BASE +0x10)
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#define SPI_RECEIVE_BUFFER_REG_ADDR (CNS3XXX_SSP_BASE +0x18)
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/* Structure for SPI controller of CNS3XXX SOCs */
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struct cns3xxx_spi {
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/* bitbang has to be first */
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struct spi_bitbang bitbang;
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struct completion done;
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wait_queue_head_t wait;
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int len;
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int count;
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int last_in_message_list;
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/* data buffers */
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const unsigned char *tx;
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unsigned char *rx;
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void __iomem *base;
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struct spi_master *master;
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struct platform_device *pdev;
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struct device *dev;
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};
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static inline u8 cns3xxx_spi_bus_idle(struct cns3xxx_spi *hw)
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{
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return ((SPI_SERVICE_STATUS_REG & 0x1) ? 0 : 1);
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}
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static inline u8 cns3xxx_spi_tx_buffer_empty(struct cns3xxx_spi *hw)
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{
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return ((SPI_INTERRUPT_STATUS_REG & (0x1 << 3)) ? 1 : 0);
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}
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static inline u8 cns3xxx_spi_rx_buffer_full(struct cns3xxx_spi *hw)
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{
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return ((SPI_INTERRUPT_STATUS_REG & (0x1 << 2)) ? 1 : 0);
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}
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u8 cns3xxx_spi_tx_rx(struct cns3xxx_spi *hw, u8 tx_channel, u8 tx_eof,
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u32 tx_data, u32 * rx_data)
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{
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u8 rx_channel;
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u8 rx_eof;
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while (!cns3xxx_spi_bus_idle(hw)) ; // do nothing
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while (!cns3xxx_spi_tx_buffer_empty(hw)) ; // do nothing
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SPI_TRANSMIT_CONTROL_REG &= ~(0x7);
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SPI_TRANSMIT_CONTROL_REG |= (tx_channel & 0x3) | ((tx_eof & 0x1) << 2);
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SPI_TRANSMIT_BUFFER_REG = tx_data;
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while (!cns3xxx_spi_rx_buffer_full(hw)) ; // do nothing
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rx_channel = SPI_RECEIVE_CONTROL_REG & 0x3;
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rx_eof = (SPI_RECEIVE_CONTROL_REG & (0x1 << 2)) ? 1 : 0;
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*rx_data = SPI_RECEIVE_BUFFER_REG;
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if ((tx_channel != rx_channel) || (tx_eof != rx_eof)) {
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return 0;
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} else {
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return 1;
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}
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}
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u8 cns3xxx_spi_tx(struct cns3xxx_spi *hw, u8 tx_channel, u8 tx_eof, u32 tx_data)
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{
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while (!cns3xxx_spi_bus_idle(hw)) ; // do nothing
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while (!cns3xxx_spi_tx_buffer_empty(hw)) ; // do nothing
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SPI_TRANSMIT_CONTROL_REG &= ~(0x7);
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SPI_TRANSMIT_CONTROL_REG |= (tx_channel & 0x3) | ((tx_eof & 0x1) << 2);
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SPI_TRANSMIT_BUFFER_REG = tx_data;
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return 1;
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}
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static inline struct cns3xxx_spi *to_hw(struct spi_device *sdev)
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{
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return spi_master_get_devdata(sdev->master);
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}
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static int cns3xxx_spi_setup_transfer(struct spi_device *spi,
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struct spi_transfer *t)
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{
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return 0;
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}
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static void cns3xxx_spi_chipselect(struct spi_device *spi, int value)
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{
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struct cns3xxx_spi *hw = to_hw(spi);
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unsigned int spi_config;
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switch (value) {
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case BITBANG_CS_INACTIVE:
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break;
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case BITBANG_CS_ACTIVE:
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spi_config = SPI_CONFIGURATION_REG;
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if (spi->mode & SPI_CPHA)
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spi_config |= (0x1 << 13);
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else
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spi_config &= ~(0x1 << 13);
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if (spi->mode & SPI_CPOL)
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spi_config |= (0x1 << 14);
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else
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spi_config &= ~(0x1 << 14);
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/* write new configration */
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SPI_CONFIGURATION_REG = spi_config;
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SPI_TRANSMIT_CONTROL_REG &= ~(0x7);
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SPI_TRANSMIT_CONTROL_REG |= (spi->chip_select & 0x3);
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break;
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}
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}
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static int cns3xxx_spi_setup(struct spi_device *spi)
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{
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if (!spi->bits_per_word)
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spi->bits_per_word = 8;
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return 0;
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}
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static int cns3xxx_spi_txrx(struct spi_device *spi, struct spi_transfer *t)
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{
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struct cns3xxx_spi *hw = to_hw(spi);
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dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n", t->tx_buf, t->rx_buf,
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t->len);
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hw->tx = t->tx_buf;
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hw->rx = t->rx_buf;
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hw->len = t->len;
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hw->count = 0;
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hw->last_in_message_list = t->last_in_message_list;
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init_completion(&hw->done);
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if (hw->tx) {
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int i;
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u32 rx_data;
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for (i = 0; i < (hw->len - 1); i++) {
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dev_dbg(&spi->dev,
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"[SPI_CNS3XXX_DEBUG] hw->tx[%02d]: 0x%02x\n", i,
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hw->tx[i]);
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cns3xxx_spi_tx_rx(hw, spi->chip_select, 0, hw->tx[i],
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&rx_data);
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if (hw->rx) {
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hw->rx[i] = rx_data;
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dev_dbg(&spi->dev,
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"[SPI_CNS3XXX_DEBUG] hw->rx[%02d]: 0x%02x\n",
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i, hw->rx[i]);
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}
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}
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if (t->last_in_message_list) {
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cns3xxx_spi_tx_rx(hw, spi->chip_select, 1, hw->tx[i],
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&rx_data);
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if (hw->rx) {
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hw->rx[i] = rx_data;
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dev_dbg(&spi->dev,
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"[SPI_CNS3XXX_DEBUG] hw->rx[%02d]: 0x%02x\n",
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i, hw->rx[i]);
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}
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} else {
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cns3xxx_spi_tx_rx(hw, spi->chip_select, 0, hw->tx[i],
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&rx_data);
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}
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goto done;
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}
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if (hw->rx) {
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int i;
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u32 rx_data;
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for (i = 0; i < (hw->len - 1); i++) {
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cns3xxx_spi_tx_rx(hw, spi->chip_select, 0, 0xff, &rx_data);
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hw->rx[i] = rx_data;
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dev_dbg(&spi->dev,
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"[SPI_CNS3XXX_DEBUG] hw->rx[%02d]: 0x%02x\n", i,
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hw->rx[i]);
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}
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if (t->last_in_message_list) {
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cns3xxx_spi_tx_rx(hw, spi->chip_select, 1, 0xff, &rx_data);
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} else {
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cns3xxx_spi_tx_rx(hw, spi->chip_select, 0, 0xff, &rx_data);
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}
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hw->rx[i] = rx_data;
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dev_dbg(&spi->dev, "[SPI_CNS3XXX_DEBUG] hw->rx[%02d]: 0x%02x\n",
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i, hw->rx[i]);
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}
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done:
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return hw->len;
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}
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static void __init cns3xxx_spi_initial(struct cns3xxx_spi *hw)
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{
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SPI_CONFIGURATION_REG = (((0x0 & 0x3) << 0) | /* 8bits shift length */
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(0x0 << 9) | /* SPI mode */
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(0x0 << 10) | /* disable FIFO */
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(0x1 << 11) | /* SPI master mode */
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(0x0 << 12) | /* disable SPI loopback mode */
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(0x1 << 13) | /* clock phase */
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(0x1 << 14) | /* clock polarity */
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(0x0 << 24) | /* disable - SPI data swap */
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(0x1 << 29) | /* enable - 2IO Read mode */
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(0x0 << 30) | /* disable - SPI high speed read for system boot up */
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(0x0 << 31)); /* disable - SPI */
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/* Set SPI bit rate PCLK/2 */
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SPI_BIT_RATE_CONTROL_REG = 0x1;
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/* Set SPI Tx channel 0 */
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SPI_TRANSMIT_CONTROL_REG = 0x0;
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/* Set Tx FIFO Threshold, Tx FIFO has 2 words */
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SPI_FIFO_TRANSMIT_CONFIG_REG &= ~(0x03 << 4);
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SPI_FIFO_TRANSMIT_CONFIG_REG |= ((0x0 & 0x03) << 4);
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/* Set Rx FIFO Threshold, Rx FIFO has 2 words */
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SPI_FIFO_RECEIVE_CONFIG_REG &= ~(0x03 << 4);
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SPI_FIFO_RECEIVE_CONFIG_REG |= ((0x0 & 0x03) << 4);
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/* Disable all interrupt */
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SPI_INTERRUPT_ENABLE_REG = 0x0;
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/* Clear spurious interrupt sources */
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SPI_INTERRUPT_STATUS_REG = (0x0F << 4);
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/* Enable SPI */
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SPI_CONFIGURATION_REG |= (0x1 << 31);
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return;
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}
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static int cns3xxx_spi_probe(struct platform_device *pdev)
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{
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struct spi_master *master;
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struct cns3xxx_spi *hw;
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struct resource *res;
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int err = 0;
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printk("%s: setup CNS3XXX SPI Controller\n", __FUNCTION__);
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res)
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return -ENODEV;
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/* Allocate master with space for cns3xxx_spi */
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master = spi_alloc_master(&pdev->dev, sizeof(struct cns3xxx_spi));
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if (master == NULL) {
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dev_err(&pdev->dev, "No memory for spi_master\n");
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err = -ENOMEM;
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goto err_nomem;
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}
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hw = spi_master_get_devdata(master);
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memset(hw, 0, sizeof(struct cns3xxx_spi));
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hw->master = spi_master_get(master);
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hw->dev = &pdev->dev;
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hw->base = devm_ioremap_resource(hw->dev, res);
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if (IS_ERR(hw->base)) {
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dev_err(hw->dev, "Unable to map registers\n");
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err = PTR_ERR(hw->base);
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goto err_register;
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}
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platform_set_drvdata(pdev, hw);
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init_completion(&hw->done);
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/* setup the master state. */
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master->num_chipselect = 4;
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master->bus_num = 1;
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/* setup the state for the bitbang driver */
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hw->bitbang.master = hw->master;
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hw->bitbang.setup_transfer = cns3xxx_spi_setup_transfer;
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hw->bitbang.chipselect = cns3xxx_spi_chipselect;
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hw->bitbang.txrx_bufs = cns3xxx_spi_txrx;
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hw->bitbang.master->setup = cns3xxx_spi_setup;
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dev_dbg(hw->dev, "bitbang at %p\n", &hw->bitbang);
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/* SPI controller initializations */
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cns3xxx_spi_initial(hw);
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/* register SPI controller */
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err = spi_bitbang_start(&hw->bitbang);
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if (err) {
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dev_err(&pdev->dev, "Failed to register SPI master\n");
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goto err_register;
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}
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return 0;
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err_register:
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spi_master_put(hw->master);;
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err_nomem:
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return err;
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}
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static int cns3xxx_spi_remove(struct platform_device *dev)
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{
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struct cns3xxx_spi *hw = platform_get_drvdata(dev);
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platform_set_drvdata(dev, NULL);
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spi_unregister_master(hw->master);
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spi_master_put(hw->master);
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return 0;
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}
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#ifdef CONFIG_PM
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static int cns3xxx_spi_suspend(struct platform_device *pdev, pm_message_t msg)
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{
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struct cns3xxx_spi *hw = platform_get_drvdata(pdev);
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return 0;
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}
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static int cns3xxx_spi_resume(struct platform_device *pdev)
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{
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struct cns3xxx_spi *hw = platform_get_drvdata(pdev);
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return 0;
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}
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#else
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#define cns3xxx_spi_suspend NULL
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#define cns3xxx_spi_resume NULL
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#endif
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static struct platform_driver cns3xxx_spi_driver = {
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.probe = cns3xxx_spi_probe,
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.remove = cns3xxx_spi_remove,
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.suspend = cns3xxx_spi_suspend,
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.resume = cns3xxx_spi_resume,
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.driver = {
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.name = "cns3xxx_spi",
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.owner = THIS_MODULE,
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},
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};
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static int __init cns3xxx_spi_init(void)
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{
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return platform_driver_register(&cns3xxx_spi_driver);
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}
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static void __exit cns3xxx_spi_exit(void)
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{
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platform_driver_unregister(&cns3xxx_spi_driver);
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}
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module_init(cns3xxx_spi_init);
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module_exit(cns3xxx_spi_exit);
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MODULE_AUTHOR("Cavium Networks");
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MODULE_DESCRIPTION("CNS3XXX SPI Controller Driver");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:cns3xxx_spi");
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EXPORT_SYMBOL_GPL(cns3xxx_spi_tx_rx);
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