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![Thomas Gleixner](/assets/img/avatar_default.png)
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms and conditions of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 263 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141901.208660670@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
322 lines
7.5 KiB
C
322 lines
7.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Special handling for DW core on Intel MID platform
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*
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* Copyright (c) 2009, 2014 Intel Corporation.
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*/
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#include <linux/dma-mapping.h>
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#include <linux/dmaengine.h>
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#include <linux/interrupt.h>
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#include <linux/slab.h>
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#include <linux/spi/spi.h>
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#include <linux/types.h>
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#include "spi-dw.h"
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#ifdef CONFIG_SPI_DW_MID_DMA
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#include <linux/pci.h>
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#include <linux/platform_data/dma-dw.h>
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#define RX_BUSY 0
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#define TX_BUSY 1
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static struct dw_dma_slave mid_dma_tx = { .dst_id = 1 };
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static struct dw_dma_slave mid_dma_rx = { .src_id = 0 };
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static bool mid_spi_dma_chan_filter(struct dma_chan *chan, void *param)
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{
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struct dw_dma_slave *s = param;
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if (s->dma_dev != chan->device->dev)
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return false;
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chan->private = s;
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return true;
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}
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static int mid_spi_dma_init(struct dw_spi *dws)
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{
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struct pci_dev *dma_dev;
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struct dw_dma_slave *tx = dws->dma_tx;
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struct dw_dma_slave *rx = dws->dma_rx;
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dma_cap_mask_t mask;
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/*
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* Get pci device for DMA controller, currently it could only
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* be the DMA controller of Medfield
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*/
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dma_dev = pci_get_device(PCI_VENDOR_ID_INTEL, 0x0827, NULL);
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if (!dma_dev)
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return -ENODEV;
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dma_cap_zero(mask);
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dma_cap_set(DMA_SLAVE, mask);
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/* 1. Init rx channel */
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rx->dma_dev = &dma_dev->dev;
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dws->rxchan = dma_request_channel(mask, mid_spi_dma_chan_filter, rx);
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if (!dws->rxchan)
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goto err_exit;
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dws->master->dma_rx = dws->rxchan;
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/* 2. Init tx channel */
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tx->dma_dev = &dma_dev->dev;
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dws->txchan = dma_request_channel(mask, mid_spi_dma_chan_filter, tx);
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if (!dws->txchan)
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goto free_rxchan;
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dws->master->dma_tx = dws->txchan;
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dws->dma_inited = 1;
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return 0;
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free_rxchan:
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dma_release_channel(dws->rxchan);
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err_exit:
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return -EBUSY;
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}
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static void mid_spi_dma_exit(struct dw_spi *dws)
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{
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if (!dws->dma_inited)
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return;
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dmaengine_terminate_sync(dws->txchan);
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dma_release_channel(dws->txchan);
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dmaengine_terminate_sync(dws->rxchan);
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dma_release_channel(dws->rxchan);
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}
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static irqreturn_t dma_transfer(struct dw_spi *dws)
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{
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u16 irq_status = dw_readl(dws, DW_SPI_ISR);
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if (!irq_status)
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return IRQ_NONE;
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dw_readl(dws, DW_SPI_ICR);
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spi_reset_chip(dws);
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dev_err(&dws->master->dev, "%s: FIFO overrun/underrun\n", __func__);
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dws->master->cur_msg->status = -EIO;
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spi_finalize_current_transfer(dws->master);
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return IRQ_HANDLED;
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}
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static bool mid_spi_can_dma(struct spi_controller *master,
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struct spi_device *spi, struct spi_transfer *xfer)
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{
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struct dw_spi *dws = spi_controller_get_devdata(master);
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if (!dws->dma_inited)
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return false;
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return xfer->len > dws->fifo_len;
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}
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static enum dma_slave_buswidth convert_dma_width(u32 dma_width) {
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if (dma_width == 1)
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return DMA_SLAVE_BUSWIDTH_1_BYTE;
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else if (dma_width == 2)
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return DMA_SLAVE_BUSWIDTH_2_BYTES;
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return DMA_SLAVE_BUSWIDTH_UNDEFINED;
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}
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/*
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* dws->dma_chan_busy is set before the dma transfer starts, callback for tx
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* channel will clear a corresponding bit.
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*/
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static void dw_spi_dma_tx_done(void *arg)
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{
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struct dw_spi *dws = arg;
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clear_bit(TX_BUSY, &dws->dma_chan_busy);
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if (test_bit(RX_BUSY, &dws->dma_chan_busy))
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return;
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spi_finalize_current_transfer(dws->master);
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}
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static struct dma_async_tx_descriptor *dw_spi_dma_prepare_tx(struct dw_spi *dws,
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struct spi_transfer *xfer)
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{
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struct dma_slave_config txconf;
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struct dma_async_tx_descriptor *txdesc;
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if (!xfer->tx_buf)
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return NULL;
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txconf.direction = DMA_MEM_TO_DEV;
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txconf.dst_addr = dws->dma_addr;
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txconf.dst_maxburst = 16;
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txconf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
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txconf.dst_addr_width = convert_dma_width(dws->dma_width);
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txconf.device_fc = false;
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dmaengine_slave_config(dws->txchan, &txconf);
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txdesc = dmaengine_prep_slave_sg(dws->txchan,
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xfer->tx_sg.sgl,
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xfer->tx_sg.nents,
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DMA_MEM_TO_DEV,
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DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
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if (!txdesc)
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return NULL;
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txdesc->callback = dw_spi_dma_tx_done;
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txdesc->callback_param = dws;
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return txdesc;
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}
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/*
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* dws->dma_chan_busy is set before the dma transfer starts, callback for rx
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* channel will clear a corresponding bit.
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*/
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static void dw_spi_dma_rx_done(void *arg)
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{
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struct dw_spi *dws = arg;
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clear_bit(RX_BUSY, &dws->dma_chan_busy);
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if (test_bit(TX_BUSY, &dws->dma_chan_busy))
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return;
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spi_finalize_current_transfer(dws->master);
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}
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static struct dma_async_tx_descriptor *dw_spi_dma_prepare_rx(struct dw_spi *dws,
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struct spi_transfer *xfer)
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{
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struct dma_slave_config rxconf;
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struct dma_async_tx_descriptor *rxdesc;
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if (!xfer->rx_buf)
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return NULL;
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rxconf.direction = DMA_DEV_TO_MEM;
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rxconf.src_addr = dws->dma_addr;
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rxconf.src_maxburst = 16;
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rxconf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
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rxconf.src_addr_width = convert_dma_width(dws->dma_width);
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rxconf.device_fc = false;
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dmaengine_slave_config(dws->rxchan, &rxconf);
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rxdesc = dmaengine_prep_slave_sg(dws->rxchan,
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xfer->rx_sg.sgl,
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xfer->rx_sg.nents,
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DMA_DEV_TO_MEM,
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DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
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if (!rxdesc)
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return NULL;
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rxdesc->callback = dw_spi_dma_rx_done;
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rxdesc->callback_param = dws;
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return rxdesc;
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}
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static int mid_spi_dma_setup(struct dw_spi *dws, struct spi_transfer *xfer)
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{
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u16 dma_ctrl = 0;
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dw_writel(dws, DW_SPI_DMARDLR, 0xf);
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dw_writel(dws, DW_SPI_DMATDLR, 0x10);
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if (xfer->tx_buf)
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dma_ctrl |= SPI_DMA_TDMAE;
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if (xfer->rx_buf)
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dma_ctrl |= SPI_DMA_RDMAE;
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dw_writel(dws, DW_SPI_DMACR, dma_ctrl);
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/* Set the interrupt mask */
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spi_umask_intr(dws, SPI_INT_TXOI | SPI_INT_RXUI | SPI_INT_RXOI);
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dws->transfer_handler = dma_transfer;
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return 0;
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}
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static int mid_spi_dma_transfer(struct dw_spi *dws, struct spi_transfer *xfer)
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{
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struct dma_async_tx_descriptor *txdesc, *rxdesc;
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/* Prepare the TX dma transfer */
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txdesc = dw_spi_dma_prepare_tx(dws, xfer);
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/* Prepare the RX dma transfer */
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rxdesc = dw_spi_dma_prepare_rx(dws, xfer);
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/* rx must be started before tx due to spi instinct */
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if (rxdesc) {
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set_bit(RX_BUSY, &dws->dma_chan_busy);
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dmaengine_submit(rxdesc);
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dma_async_issue_pending(dws->rxchan);
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}
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if (txdesc) {
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set_bit(TX_BUSY, &dws->dma_chan_busy);
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dmaengine_submit(txdesc);
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dma_async_issue_pending(dws->txchan);
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}
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return 0;
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}
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static void mid_spi_dma_stop(struct dw_spi *dws)
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{
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if (test_bit(TX_BUSY, &dws->dma_chan_busy)) {
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dmaengine_terminate_sync(dws->txchan);
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clear_bit(TX_BUSY, &dws->dma_chan_busy);
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}
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if (test_bit(RX_BUSY, &dws->dma_chan_busy)) {
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dmaengine_terminate_sync(dws->rxchan);
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clear_bit(RX_BUSY, &dws->dma_chan_busy);
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}
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}
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static const struct dw_spi_dma_ops mid_dma_ops = {
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.dma_init = mid_spi_dma_init,
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.dma_exit = mid_spi_dma_exit,
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.dma_setup = mid_spi_dma_setup,
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.can_dma = mid_spi_can_dma,
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.dma_transfer = mid_spi_dma_transfer,
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.dma_stop = mid_spi_dma_stop,
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};
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#endif
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/* Some specific info for SPI0 controller on Intel MID */
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/* HW info for MRST Clk Control Unit, 32b reg per controller */
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#define MRST_SPI_CLK_BASE 100000000 /* 100m */
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#define MRST_CLK_SPI_REG 0xff11d86c
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#define CLK_SPI_BDIV_OFFSET 0
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#define CLK_SPI_BDIV_MASK 0x00000007
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#define CLK_SPI_CDIV_OFFSET 9
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#define CLK_SPI_CDIV_MASK 0x00000e00
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#define CLK_SPI_DISABLE_OFFSET 8
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int dw_spi_mid_init(struct dw_spi *dws)
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{
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void __iomem *clk_reg;
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u32 clk_cdiv;
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clk_reg = ioremap_nocache(MRST_CLK_SPI_REG, 16);
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if (!clk_reg)
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return -ENOMEM;
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/* Get SPI controller operating freq info */
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clk_cdiv = readl(clk_reg + dws->bus_num * sizeof(u32));
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clk_cdiv &= CLK_SPI_CDIV_MASK;
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clk_cdiv >>= CLK_SPI_CDIV_OFFSET;
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dws->max_freq = MRST_SPI_CLK_BASE / (clk_cdiv + 1);
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iounmap(clk_reg);
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#ifdef CONFIG_SPI_DW_MID_DMA
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dws->dma_tx = &mid_dma_tx;
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dws->dma_rx = &mid_dma_rx;
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dws->dma_ops = &mid_dma_ops;
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#endif
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return 0;
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}
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