diff options
| -rw-r--r-- | drivers/mmc/host/mmci.c | 282 | ||||
| -rw-r--r-- | drivers/mmc/host/mmci.h | 13 | ||||
| -rw-r--r-- | include/linux/amba/mmci.h | 17 |
3 files changed, 304 insertions, 8 deletions
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c index db2a358143d6..8a29c9f4a812 100644 --- a/drivers/mmc/host/mmci.c +++ b/drivers/mmc/host/mmci.c @@ -2,7 +2,7 @@ * 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 @@ -25,8 +25,10 @@ #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> @@ -186,6 +188,248 @@ static void mmci_init_sg(struct mmci_host *host, struct mmc_data *data) 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; @@ -201,8 +445,6 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data) 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); @@ -216,8 +458,21 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data) 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; /* @@ -281,6 +536,10 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *data, 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 @@ -315,6 +574,8 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *data, 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) @@ -767,6 +1028,7 @@ static int __devinit mmci_probe(struct amba_device *dev, struct amba_id *id) 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; @@ -894,9 +1156,12 @@ static int __devinit mmci_probe(struct amba_device *dev, struct amba_id *id) 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); @@ -943,6 +1208,7 @@ static int __devexit mmci_remove(struct amba_device *dev) 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); diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h index 164ce060fc1f..ec9a7bc6d0df 100644 --- a/drivers/mmc/host/mmci.h +++ b/drivers/mmc/host/mmci.h @@ -148,8 +148,10 @@ struct clk; struct variant_data; +struct dma_chan; struct mmci_host { + phys_addr_t phybase; void __iomem *base; struct mmc_request *mrq; struct mmc_command *cmd; @@ -179,5 +181,16 @@ struct mmci_host { struct sg_mapping_iter sg_miter; unsigned int size; struct regulator *vcc; + +#ifdef CONFIG_DMA_ENGINE + /* DMA stuff */ + struct dma_chan *dma_current; + struct dma_chan *dma_rx_channel; + struct dma_chan *dma_tx_channel; + +#define dma_inprogress(host) ((host)->dma_current) +#else +#define dma_inprogress(host) (0) +#endif }; diff --git a/include/linux/amba/mmci.h b/include/linux/amba/mmci.h index f4ee9acc9721..f60227088b7b 100644 --- a/include/linux/amba/mmci.h +++ b/include/linux/amba/mmci.h @@ -6,6 +6,9 @@ #include <linux/mmc/host.h> +/* Just some dummy forwarding */ +struct dma_chan; + /** * struct mmci_platform_data - platform configuration for the MMCI * (also known as PL180) block. @@ -27,6 +30,17 @@ * @cd_invert: true if the gpio_cd pin value is active low * @capabilities: the capabilities of the block as implemented in * this platform, signify anything MMC_CAP_* from mmc/host.h + * @dma_filter: function used to select an apropriate RX and TX + * DMA channel to be used for DMA, if and only if you're deploying the + * generic DMA engine + * @dma_rx_param: parameter passed to the DMA allocation + * filter in order to select an apropriate RX channel. If + * there is a bidirectional RX+TX channel, then just specify + * this and leave dma_tx_param set to NULL + * @dma_tx_param: parameter passed to the DMA allocation + * filter in order to select an apropriate TX channel. If this + * is NULL the driver will attempt to use the RX channel as a + * bidirectional channel */ struct mmci_platform_data { unsigned int f_max; @@ -38,6 +52,9 @@ struct mmci_platform_data { int gpio_cd; bool cd_invert; unsigned long capabilities; + bool (*dma_filter)(struct dma_chan *chan, void *filter_param); + void *dma_rx_param; + void *dma_tx_param; }; #endif |