* linux/drivers/mmc/host/mmci.c - ARM PrimeCell MMCI PL180/1 driver
*
* Copyright (C) 2003 Deep Blue Solutions, Ltd, All Rights Reserved.
- * Copyright (C) 2010 ST-Ericsson AB.
+ * Copyright (C) 2010 ST-Ericsson SA
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
#include <linux/clk.h>
#include <linux/scatterlist.h>
#include <linux/gpio.h>
-#include <linux/amba/mmci.h>
#include <linux/regulator/consumer.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/amba/mmci.h>
#include <asm/div64.h>
#include <asm/io.h>
sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags);
}
+/*
+ * All the DMA operation mode stuff goes inside this ifdef.
+ * This assumes that you have a generic DMA device interface,
+ * no custom DMA interfaces are supported.
+ */
+#ifdef CONFIG_DMA_ENGINE
+static void __devinit mmci_dma_setup(struct mmci_host *host)
+{
+ struct mmci_platform_data *plat = host->plat;
+ const char *rxname, *txname;
+ dma_cap_mask_t mask;
+
+ if (!plat || !plat->dma_filter) {
+ dev_info(mmc_dev(host->mmc), "no DMA platform data\n");
+ return;
+ }
+
+ /* Try to acquire a generic DMA engine slave channel */
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+
+ /*
+ * If only an RX channel is specified, the driver will
+ * attempt to use it bidirectionally, however if it is
+ * is specified but cannot be located, DMA will be disabled.
+ */
+ if (plat->dma_rx_param) {
+ host->dma_rx_channel = dma_request_channel(mask,
+ plat->dma_filter,
+ plat->dma_rx_param);
+ /* E.g if no DMA hardware is present */
+ if (!host->dma_rx_channel)
+ dev_err(mmc_dev(host->mmc), "no RX DMA channel\n");
+ }
+
+ if (plat->dma_tx_param) {
+ host->dma_tx_channel = dma_request_channel(mask,
+ plat->dma_filter,
+ plat->dma_tx_param);
+ if (!host->dma_tx_channel)
+ dev_warn(mmc_dev(host->mmc), "no TX DMA channel\n");
+ } else {
+ host->dma_tx_channel = host->dma_rx_channel;
+ }
+
+ if (host->dma_rx_channel)
+ rxname = dma_chan_name(host->dma_rx_channel);
+ else
+ rxname = "none";
+
+ if (host->dma_tx_channel)
+ txname = dma_chan_name(host->dma_tx_channel);
+ else
+ txname = "none";
+
+ dev_info(mmc_dev(host->mmc), "DMA channels RX %s, TX %s\n",
+ rxname, txname);
+
+ /*
+ * Limit the maximum segment size in any SG entry according to
+ * the parameters of the DMA engine device.
+ */
+ if (host->dma_tx_channel) {
+ struct device *dev = host->dma_tx_channel->device->dev;
+ unsigned int max_seg_size = dma_get_max_seg_size(dev);
+
+ if (max_seg_size < host->mmc->max_seg_size)
+ host->mmc->max_seg_size = max_seg_size;
+ }
+ if (host->dma_rx_channel) {
+ struct device *dev = host->dma_rx_channel->device->dev;
+ unsigned int max_seg_size = dma_get_max_seg_size(dev);
+
+ if (max_seg_size < host->mmc->max_seg_size)
+ host->mmc->max_seg_size = max_seg_size;
+ }
+}
+
+/*
+ * This is used in __devinit or __devexit so inline it
+ * so it can be discarded.
+ */
+static inline void mmci_dma_release(struct mmci_host *host)
+{
+ struct mmci_platform_data *plat = host->plat;
+
+ if (host->dma_rx_channel)
+ dma_release_channel(host->dma_rx_channel);
+ if (host->dma_tx_channel && plat->dma_tx_param)
+ dma_release_channel(host->dma_tx_channel);
+ host->dma_rx_channel = host->dma_tx_channel = NULL;
+}
+
+static void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
+{
+ struct dma_chan *chan = host->dma_current;
+ enum dma_data_direction dir;
+ u32 status;
+ int i;
+
+ /* Wait up to 1ms for the DMA to complete */
+ for (i = 0; ; i++) {
+ status = readl(host->base + MMCISTATUS);
+ if (!(status & MCI_RXDATAAVLBLMASK) || i >= 100)
+ break;
+ udelay(10);
+ }
+
+ /*
+ * Check to see whether we still have some data left in the FIFO -
+ * this catches DMA controllers which are unable to monitor the
+ * DMALBREQ and DMALSREQ signals while allowing us to DMA to non-
+ * contiguous buffers. On TX, we'll get a FIFO underrun error.
+ */
+ if (status & MCI_RXDATAAVLBLMASK) {
+ dmaengine_terminate_all(chan);
+ if (!data->error)
+ data->error = -EIO;
+ }
+
+ if (data->flags & MMC_DATA_WRITE) {
+ dir = DMA_TO_DEVICE;
+ } else {
+ dir = DMA_FROM_DEVICE;
+ }
+
+ dma_unmap_sg(chan->device->dev, data->sg, data->sg_len, dir);
+
+ /*
+ * Use of DMA with scatter-gather is impossible.
+ * Give up with DMA and switch back to PIO mode.
+ */
+ if (status & MCI_RXDATAAVLBLMASK) {
+ dev_err(mmc_dev(host->mmc), "buggy DMA detected. Taking evasive action.\n");
+ mmci_dma_release(host);
+ }
+}
+
+static void mmci_dma_data_error(struct mmci_host *host)
+{
+ dev_err(mmc_dev(host->mmc), "error during DMA transfer!\n");
+ dmaengine_terminate_all(host->dma_current);
+}
+
+static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
+{
+ struct variant_data *variant = host->variant;
+ struct dma_slave_config conf = {
+ .src_addr = host->phybase + MMCIFIFO,
+ .dst_addr = host->phybase + MMCIFIFO,
+ .src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
+ .dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
+ .src_maxburst = variant->fifohalfsize >> 2, /* # of words */
+ .dst_maxburst = variant->fifohalfsize >> 2, /* # of words */
+ };
+ struct mmc_data *data = host->data;
+ struct dma_chan *chan;
+ struct dma_device *device;
+ struct dma_async_tx_descriptor *desc;
+ int nr_sg;
+
+ host->dma_current = NULL;
+
+ if (data->flags & MMC_DATA_READ) {
+ conf.direction = DMA_FROM_DEVICE;
+ chan = host->dma_rx_channel;
+ } else {
+ conf.direction = DMA_TO_DEVICE;
+ chan = host->dma_tx_channel;
+ }
+
+ /* If there's no DMA channel, fall back to PIO */
+ if (!chan)
+ return -EINVAL;
+
+ /* If less than or equal to the fifo size, don't bother with DMA */
+ if (host->size <= variant->fifosize)
+ return -EINVAL;
+
+ device = chan->device;
+ nr_sg = dma_map_sg(device->dev, data->sg, data->sg_len, conf.direction);
+ if (nr_sg == 0)
+ return -EINVAL;
+
+ dmaengine_slave_config(chan, &conf);
+ desc = device->device_prep_slave_sg(chan, data->sg, nr_sg,
+ conf.direction, DMA_CTRL_ACK);
+ if (!desc)
+ goto unmap_exit;
+
+ /* Okay, go for it. */
+ host->dma_current = chan;
+
+ dev_vdbg(mmc_dev(host->mmc),
+ "Submit MMCI DMA job, sglen %d blksz %04x blks %04x flags %08x\n",
+ data->sg_len, data->blksz, data->blocks, data->flags);
+ dmaengine_submit(desc);
+ dma_async_issue_pending(chan);
+
+ datactrl |= MCI_DPSM_DMAENABLE;
+
+ /* Trigger the DMA transfer */
+ writel(datactrl, host->base + MMCIDATACTRL);
+
+ /*
+ * Let the MMCI say when the data is ended and it's time
+ * to fire next DMA request. When that happens, MMCI will
+ * call mmci_data_end()
+ */
+ writel(readl(host->base + MMCIMASK0) | MCI_DATAENDMASK,
+ host->base + MMCIMASK0);
+ return 0;
+
+unmap_exit:
+ dmaengine_terminate_all(chan);
+ dma_unmap_sg(device->dev, data->sg, data->sg_len, conf.direction);
+ return -ENOMEM;
+}
+#else
+/* Blank functions if the DMA engine is not available */
+static inline void mmci_dma_setup(struct mmci_host *host)
+{
+}
+
+static inline void mmci_dma_release(struct mmci_host *host)
+{
+}
+
+static inline void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
+{
+}
+
+static inline void mmci_dma_data_error(struct mmci_host *host)
+{
+}
+
+static inline int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
+{
+ return -ENOSYS;
+}
+#endif
+
static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
{
struct variant_data *variant = host->variant;
host->size = data->blksz * data->blocks;
data->bytes_xfered = 0;
- mmci_init_sg(host, data);
-
clks = (unsigned long long)data->timeout_ns * host->cclk;
do_div(clks, 1000000000UL);
BUG_ON(1 << blksz_bits != data->blksz);
datactrl = MCI_DPSM_ENABLE | blksz_bits << 4;
- if (data->flags & MMC_DATA_READ) {
+
+ if (data->flags & MMC_DATA_READ)
datactrl |= MCI_DPSM_DIRECTION;
+
+ /*
+ * Attempt to use DMA operation mode, if this
+ * should fail, fall back to PIO mode
+ */
+ if (!mmci_dma_start_data(host, datactrl))
+ return;
+
+ /* IRQ mode, map the SG list for CPU reading/writing */
+ mmci_init_sg(host, data);
+
+ if (data->flags & MMC_DATA_READ) {
irqmask = MCI_RXFIFOHALFFULLMASK;
/*
if (status & (MCI_DATACRCFAIL|MCI_DATATIMEOUT|MCI_TXUNDERRUN|MCI_RXOVERRUN)) {
u32 remain, success;
+ /* Terminate the DMA transfer */
+ if (dma_inprogress(host))
+ mmci_dma_data_error(host);
+
/*
* Calculate how far we are into the transfer. Note that
* the data counter gives the number of bytes transferred
dev_err(mmc_dev(host->mmc), "stray MCI_DATABLOCKEND interrupt\n");
if (status & MCI_DATAEND || data->error) {
+ if (dma_inprogress(host))
+ mmci_dma_unmap(host, data);
mmci_stop_data(host);
if (!data->error)
dev_dbg(mmc_dev(mmc), "eventual mclk rate: %u Hz\n",
host->mclk);
}
+ host->phybase = dev->res.start;
host->base = ioremap(dev->res.start, resource_size(&dev->res));
if (!host->base) {
ret = -ENOMEM;
amba_set_drvdata(dev, mmc);
- dev_info(&dev->dev, "%s: PL%03x rev%u at 0x%08llx irq %d,%d\n",
- mmc_hostname(mmc), amba_part(dev), amba_rev(dev),
- (unsigned long long)dev->res.start, dev->irq[0], dev->irq[1]);
+ dev_info(&dev->dev, "%s: PL%03x manf %x rev%u at 0x%08llx irq %d,%d (pio)\n",
+ mmc_hostname(mmc), amba_part(dev), amba_manf(dev),
+ amba_rev(dev), (unsigned long long)dev->res.start,
+ dev->irq[0], dev->irq[1]);
+
+ mmci_dma_setup(host);
mmc_add_host(mmc);
writel(0, host->base + MMCICOMMAND);
writel(0, host->base + MMCIDATACTRL);
+ mmci_dma_release(host);
free_irq(dev->irq[0], host);
if (!host->singleirq)
free_irq(dev->irq[1], host);
git.openpandora.org / pandora-kernel.git / commitdiff