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author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/drivers/spi/spi-dw-mid.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/drivers/spi/spi-dw-mid.c')
-rw-r--r-- | kernel/drivers/spi/spi-dw-mid.c | 330 |
1 files changed, 330 insertions, 0 deletions
diff --git a/kernel/drivers/spi/spi-dw-mid.c b/kernel/drivers/spi/spi-dw-mid.c new file mode 100644 index 000000000..bb1052e74 --- /dev/null +++ b/kernel/drivers/spi/spi-dw-mid.c @@ -0,0 +1,330 @@ +/* + * Special handling for DW core on Intel MID platform + * + * Copyright (c) 2009, 2014 Intel Corporation. + * + * 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. + */ + +#include <linux/dma-mapping.h> +#include <linux/dmaengine.h> +#include <linux/interrupt.h> +#include <linux/slab.h> +#include <linux/spi/spi.h> +#include <linux/types.h> + +#include "spi-dw.h" + +#ifdef CONFIG_SPI_DW_MID_DMA +#include <linux/pci.h> +#include <linux/platform_data/dma-dw.h> + +#define RX_BUSY 0 +#define TX_BUSY 1 + +static struct dw_dma_slave mid_dma_tx = { .dst_id = 1 }; +static struct dw_dma_slave mid_dma_rx = { .src_id = 0 }; + +static bool mid_spi_dma_chan_filter(struct dma_chan *chan, void *param) +{ + struct dw_dma_slave *s = param; + + if (s->dma_dev != chan->device->dev) + return false; + + chan->private = s; + return true; +} + +static int mid_spi_dma_init(struct dw_spi *dws) +{ + struct pci_dev *dma_dev; + struct dw_dma_slave *tx = dws->dma_tx; + struct dw_dma_slave *rx = dws->dma_rx; + dma_cap_mask_t mask; + + /* + * Get pci device for DMA controller, currently it could only + * be the DMA controller of Medfield + */ + dma_dev = pci_get_device(PCI_VENDOR_ID_INTEL, 0x0827, NULL); + if (!dma_dev) + return -ENODEV; + + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + + /* 1. Init rx channel */ + rx->dma_dev = &dma_dev->dev; + dws->rxchan = dma_request_channel(mask, mid_spi_dma_chan_filter, rx); + if (!dws->rxchan) + goto err_exit; + dws->master->dma_rx = dws->rxchan; + + /* 2. Init tx channel */ + tx->dma_dev = &dma_dev->dev; + dws->txchan = dma_request_channel(mask, mid_spi_dma_chan_filter, tx); + if (!dws->txchan) + goto free_rxchan; + dws->master->dma_tx = dws->txchan; + + dws->dma_inited = 1; + return 0; + +free_rxchan: + dma_release_channel(dws->rxchan); +err_exit: + return -EBUSY; +} + +static void mid_spi_dma_exit(struct dw_spi *dws) +{ + if (!dws->dma_inited) + return; + + dmaengine_terminate_all(dws->txchan); + dma_release_channel(dws->txchan); + + dmaengine_terminate_all(dws->rxchan); + dma_release_channel(dws->rxchan); +} + +static irqreturn_t dma_transfer(struct dw_spi *dws) +{ + u16 irq_status = dw_readl(dws, DW_SPI_ISR); + + if (!irq_status) + return IRQ_NONE; + + dw_readl(dws, DW_SPI_ICR); + spi_reset_chip(dws); + + dev_err(&dws->master->dev, "%s: FIFO overrun/underrun\n", __func__); + dws->master->cur_msg->status = -EIO; + spi_finalize_current_transfer(dws->master); + return IRQ_HANDLED; +} + +static bool mid_spi_can_dma(struct spi_master *master, struct spi_device *spi, + struct spi_transfer *xfer) +{ + struct dw_spi *dws = spi_master_get_devdata(master); + + if (!dws->dma_inited) + return false; + + return xfer->len > dws->fifo_len; +} + +static enum dma_slave_buswidth convert_dma_width(u32 dma_width) { + if (dma_width == 1) + return DMA_SLAVE_BUSWIDTH_1_BYTE; + else if (dma_width == 2) + return DMA_SLAVE_BUSWIDTH_2_BYTES; + + return DMA_SLAVE_BUSWIDTH_UNDEFINED; +} + +/* + * dws->dma_chan_busy is set before the dma transfer starts, callback for tx + * channel will clear a corresponding bit. + */ +static void dw_spi_dma_tx_done(void *arg) +{ + struct dw_spi *dws = arg; + + clear_bit(TX_BUSY, &dws->dma_chan_busy); + if (test_bit(RX_BUSY, &dws->dma_chan_busy)) + return; + spi_finalize_current_transfer(dws->master); +} + +static struct dma_async_tx_descriptor *dw_spi_dma_prepare_tx(struct dw_spi *dws, + struct spi_transfer *xfer) +{ + struct dma_slave_config txconf; + struct dma_async_tx_descriptor *txdesc; + + if (!xfer->tx_buf) + return NULL; + + txconf.direction = DMA_MEM_TO_DEV; + txconf.dst_addr = dws->dma_addr; + txconf.dst_maxburst = 16; + txconf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; + txconf.dst_addr_width = convert_dma_width(dws->dma_width); + txconf.device_fc = false; + + dmaengine_slave_config(dws->txchan, &txconf); + + txdesc = dmaengine_prep_slave_sg(dws->txchan, + xfer->tx_sg.sgl, + xfer->tx_sg.nents, + DMA_MEM_TO_DEV, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!txdesc) + return NULL; + + txdesc->callback = dw_spi_dma_tx_done; + txdesc->callback_param = dws; + + return txdesc; +} + +/* + * dws->dma_chan_busy is set before the dma transfer starts, callback for rx + * channel will clear a corresponding bit. + */ +static void dw_spi_dma_rx_done(void *arg) +{ + struct dw_spi *dws = arg; + + clear_bit(RX_BUSY, &dws->dma_chan_busy); + if (test_bit(TX_BUSY, &dws->dma_chan_busy)) + return; + spi_finalize_current_transfer(dws->master); +} + +static struct dma_async_tx_descriptor *dw_spi_dma_prepare_rx(struct dw_spi *dws, + struct spi_transfer *xfer) +{ + struct dma_slave_config rxconf; + struct dma_async_tx_descriptor *rxdesc; + + if (!xfer->rx_buf) + return NULL; + + rxconf.direction = DMA_DEV_TO_MEM; + rxconf.src_addr = dws->dma_addr; + rxconf.src_maxburst = 16; + rxconf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; + rxconf.src_addr_width = convert_dma_width(dws->dma_width); + rxconf.device_fc = false; + + dmaengine_slave_config(dws->rxchan, &rxconf); + + rxdesc = dmaengine_prep_slave_sg(dws->rxchan, + xfer->rx_sg.sgl, + xfer->rx_sg.nents, + DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!rxdesc) + return NULL; + + rxdesc->callback = dw_spi_dma_rx_done; + rxdesc->callback_param = dws; + + return rxdesc; +} + +static int mid_spi_dma_setup(struct dw_spi *dws, struct spi_transfer *xfer) +{ + u16 dma_ctrl = 0; + + dw_writel(dws, DW_SPI_DMARDLR, 0xf); + dw_writel(dws, DW_SPI_DMATDLR, 0x10); + + if (xfer->tx_buf) + dma_ctrl |= SPI_DMA_TDMAE; + if (xfer->rx_buf) + dma_ctrl |= SPI_DMA_RDMAE; + dw_writel(dws, DW_SPI_DMACR, dma_ctrl); + + /* Set the interrupt mask */ + spi_umask_intr(dws, SPI_INT_TXOI | SPI_INT_RXUI | SPI_INT_RXOI); + + dws->transfer_handler = dma_transfer; + + return 0; +} + +static int mid_spi_dma_transfer(struct dw_spi *dws, struct spi_transfer *xfer) +{ + struct dma_async_tx_descriptor *txdesc, *rxdesc; + + /* Prepare the TX dma transfer */ + txdesc = dw_spi_dma_prepare_tx(dws, xfer); + + /* Prepare the RX dma transfer */ + rxdesc = dw_spi_dma_prepare_rx(dws, xfer); + + /* rx must be started before tx due to spi instinct */ + if (rxdesc) { + set_bit(RX_BUSY, &dws->dma_chan_busy); + dmaengine_submit(rxdesc); + dma_async_issue_pending(dws->rxchan); + } + + if (txdesc) { + set_bit(TX_BUSY, &dws->dma_chan_busy); + dmaengine_submit(txdesc); + dma_async_issue_pending(dws->txchan); + } + + return 0; +} + +static void mid_spi_dma_stop(struct dw_spi *dws) +{ + if (test_bit(TX_BUSY, &dws->dma_chan_busy)) { + dmaengine_terminate_all(dws->txchan); + clear_bit(TX_BUSY, &dws->dma_chan_busy); + } + if (test_bit(RX_BUSY, &dws->dma_chan_busy)) { + dmaengine_terminate_all(dws->rxchan); + clear_bit(RX_BUSY, &dws->dma_chan_busy); + } +} + +static struct dw_spi_dma_ops mid_dma_ops = { + .dma_init = mid_spi_dma_init, + .dma_exit = mid_spi_dma_exit, + .dma_setup = mid_spi_dma_setup, + .can_dma = mid_spi_can_dma, + .dma_transfer = mid_spi_dma_transfer, + .dma_stop = mid_spi_dma_stop, +}; +#endif + +/* Some specific info for SPI0 controller on Intel MID */ + +/* HW info for MRST Clk Control Unit, 32b reg per controller */ +#define MRST_SPI_CLK_BASE 100000000 /* 100m */ +#define MRST_CLK_SPI_REG 0xff11d86c +#define CLK_SPI_BDIV_OFFSET 0 +#define CLK_SPI_BDIV_MASK 0x00000007 +#define CLK_SPI_CDIV_OFFSET 9 +#define CLK_SPI_CDIV_MASK 0x00000e00 +#define CLK_SPI_DISABLE_OFFSET 8 + +int dw_spi_mid_init(struct dw_spi *dws) +{ + void __iomem *clk_reg; + u32 clk_cdiv; + + clk_reg = ioremap_nocache(MRST_CLK_SPI_REG, 16); + if (!clk_reg) + return -ENOMEM; + + /* Get SPI controller operating freq info */ + clk_cdiv = readl(clk_reg + dws->bus_num * sizeof(u32)); + clk_cdiv &= CLK_SPI_CDIV_MASK; + clk_cdiv >>= CLK_SPI_CDIV_OFFSET; + dws->max_freq = MRST_SPI_CLK_BASE / (clk_cdiv + 1); + + iounmap(clk_reg); + +#ifdef CONFIG_SPI_DW_MID_DMA + dws->dma_tx = &mid_dma_tx; + dws->dma_rx = &mid_dma_rx; + dws->dma_ops = &mid_dma_ops; +#endif + return 0; +} |