From 358a2dc59dacf1c33edb6d72967e860315e94097 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Thu, 8 Apr 2010 00:49:27 +0200 Subject: [PATCH 22/26] ARM: add PrimeCell generic DMA to MMCI/PL180 v5 This extends the MMCI/PL180 driver with generic DMA engine support using the PrimeCell DMA engine interface. Signed-off-by: Linus Walleij --- drivers/mmc/host/mmci.c | 290 ++++++++++++++++++++++++++++++++++++++------- drivers/mmc/host/mmci.h | 7 +- include/linux/amba/mmci.h | 16 +++ 3 files changed, 268 insertions(+), 45 deletions(-) diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c index ff115d9..37ab678 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 @@ -23,8 +23,11 @@ #include #include #include -#include #include +#include +#include +#include +#include #include #include @@ -98,12 +101,209 @@ static void mmci_stop_data(struct mmci_host *host) host->data = NULL; } +static void +mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c) +{ + void __iomem *base = host->base; + + dev_dbg(mmc_dev(host->mmc), "op %02x arg %08x flags %08x\n", + cmd->opcode, cmd->arg, cmd->flags); + + if (readl(base + MMCICOMMAND) & MCI_CPSM_ENABLE) { + writel(0, base + MMCICOMMAND); + udelay(1); + } + + c |= cmd->opcode | MCI_CPSM_ENABLE; + if (cmd->flags & MMC_RSP_PRESENT) { + if (cmd->flags & MMC_RSP_136) + c |= MCI_CPSM_LONGRSP; + c |= MCI_CPSM_RESPONSE; + } + if (/*interrupt*/0) + c |= MCI_CPSM_INTERRUPT; + + host->cmd = cmd; + + writel(cmd->arg, base + MMCIARGUMENT); + writel(c, base + MMCICOMMAND); +} + +/* + * 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_DMADEVICES +static void __devinit mmci_setup_dma(struct mmci_host *host) +{ + struct mmci_platform_data *plat = host->plat; + dma_cap_mask_t mask; + + /* 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. + */ + host->dma_rx_channel = dma_request_channel(mask, + plat->dma_filter, + plat->dma_rx_param); + 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) { + dma_release_channel(host->dma_rx_channel); + host->dma_rx_channel = NULL; + } + } else { + host->dma_tx_channel = host->dma_rx_channel; + } +} + +static void __devexit mmci_disable_dma(struct mmci_host *host) +{ + if (host->dma_rx_channel) + dma_release_channel(host->dma_rx_channel); + if (host->dma_tx_channel) + dma_release_channel(host->dma_tx_channel); +} + +static void mmci_dma_data_end(struct mmci_host *host) +{ + struct mmc_data *data = host->data; + + dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len, + (data->flags & MMC_DATA_WRITE) + ? DMA_TO_DEVICE : DMA_FROM_DEVICE); +} + +static void mmci_dma_data_error(struct mmci_host *host) +{ + struct mmc_data *data = host->data; + struct dma_chan *chan; + + dev_err(mmc_dev(host->mmc), "error during DMA transfer!\n"); + if (data->flags & MMC_DATA_READ) + chan = host->dma_rx_channel; + else + chan = host->dma_tx_channel; + dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len, + (data->flags & MMC_DATA_WRITE) + ? DMA_TO_DEVICE : DMA_FROM_DEVICE); + chan->device->device_control(chan, DMA_TERMINATE_ALL); +} + +/* + * This one gets called repeatedly to copy data using + * DMA until there is no more data left to copy. + */ +static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl) +{ + struct amba_dma_channel_config rx_conf = { + .addr = host->phybase + MMCIFIFO, + .addr_width = 4, + .direction = DMA_FROM_DEVICE, + .maxburst = 8, + }; + struct amba_dma_channel_config tx_conf = { + .addr = host->phybase + MMCIFIFO, + .addr_width = 4, + .direction = DMA_TO_DEVICE, + .maxburst = 8, + }; + struct mmc_data *data = host->data; + enum dma_data_direction direction; + struct dma_chan *chan; + struct dma_async_tx_descriptor *desc; + struct scatterlist *sg; + unsigned int sglen; + int i; + + datactrl |= MCI_DPSM_DMAENABLE; + if (data->flags & MMC_DATA_READ) { + direction = DMA_FROM_DEVICE; + chan = host->dma_rx_channel; + dma_set_ambaconfig(chan, &rx_conf); + } else { + direction = DMA_TO_DEVICE; + chan = host->dma_tx_channel; + dma_set_ambaconfig(chan, &tx_conf); + } + + /* Check for weird stuff in the sg list */ + for_each_sg(data->sg, sg, data->sg_len, i) { + if (sg->offset & 3 || sg->length & 3) + return -EINVAL; + } + + sglen = dma_map_sg(mmc_dev(host->mmc), data->sg, + data->sg_len, direction); + if (sglen != data->sg_len) + goto unmap_exit; + + desc = chan->device->device_prep_slave_sg(chan, + data->sg, data->sg_len, direction, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) + goto unmap_exit; + + host->dma_desc = desc; + dev_vdbg(mmc_dev(host->mmc), "Submit MMCI DMA job, sglen %d " + "blksz %04x blks %04x flags %08x\n", + sglen, data->blksz, data->blocks, data->flags); + desc->tx_submit(desc); + chan->device->device_issue_pending(chan); + + /* 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: + dma_unmap_sg(mmc_dev(host->mmc), data->sg, sglen, direction); + return -ENOMEM; +} +#else +/* Blank functions if the DMA engine is not available */ +static inline void mmci_setup_dma(struct mmci_host *host) +{ +} + +static inline void mmci_disable_dma(struct mmci_host *host) +{ +} + +static inline void mmci_dma_data_end(struct mmci_host *host) +{ +} + +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) { unsigned int datactrl, timeout, irqmask; unsigned long long clks; void __iomem *base; int blksz_bits; + int ret; dev_dbg(mmc_dev(host->mmc), "blksz %04x blks %04x flags %08x\n", data->blksz, data->blocks, data->flags); @@ -112,8 +312,6 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data) host->size = data->blksz; host->data_xfered = 0; - mmci_init_sg(host, data); - clks = (unsigned long long)data->timeout_ns * host->cclk; do_div(clks, 1000000000UL); @@ -127,13 +325,30 @@ 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; + + if (host->dma_rx_channel) { + /* + * Attempt to use DMA operation mode, if this + * should fail, fall back to PIO mode + */ + ret = mmci_dma_start_data(host, datactrl); + if (!ret) + 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 we have less than a FIFOSIZE of bytes to transfer, - * trigger a PIO interrupt as soon as any data is available. + * If we have less than a FIFOSIZE of bytes to + * transfer, trigger a PIO interrupt as soon as any + * data is available. */ if (host->size < MCI_FIFOSIZE) irqmask |= MCI_RXDATAAVLBLMASK; @@ -146,39 +361,12 @@ static void mmci_start_data(struct mmci_host *host, struct mmc_data *data) } writel(datactrl, base + MMCIDATACTRL); + /* No interrupt when data ends */ writel(readl(base + MMCIMASK0) & ~MCI_DATAENDMASK, base + MMCIMASK0); writel(irqmask, base + MMCIMASK1); } static void -mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c) -{ - void __iomem *base = host->base; - - dev_dbg(mmc_dev(host->mmc), "op %02x arg %08x flags %08x\n", - cmd->opcode, cmd->arg, cmd->flags); - - if (readl(base + MMCICOMMAND) & MCI_CPSM_ENABLE) { - writel(0, base + MMCICOMMAND); - udelay(1); - } - - c |= cmd->opcode | MCI_CPSM_ENABLE; - if (cmd->flags & MMC_RSP_PRESENT) { - if (cmd->flags & MMC_RSP_136) - c |= MCI_CPSM_LONGRSP; - c |= MCI_CPSM_RESPONSE; - } - if (/*interrupt*/0) - c |= MCI_CPSM_INTERRUPT; - - host->cmd = cmd; - - writel(cmd->arg, base + MMCIARGUMENT); - writel(c, base + MMCICOMMAND); -} - -static void mmci_data_irq(struct mmci_host *host, struct mmc_data *data, unsigned int status) { @@ -206,14 +394,19 @@ mmci_data_irq(struct mmci_host *host, struct mmc_data *data, data->error = -EIO; status |= MCI_DATAEND; - /* - * We hit an error condition. Ensure that any data - * partially written to a page is properly coherent. - */ - if (host->sg_len && data->flags & MMC_DATA_READ) - flush_dcache_page(sg_page(host->sg_ptr)); + if (host->dma_rx_channel) { + mmci_dma_data_error(host); + } else { + /* + * We hit an error condition. Ensure that any data + * partially written to a page is properly coherent. + */ + if (host->sg_len && data->flags & MMC_DATA_READ) + flush_dcache_page(sg_page(host->sg_ptr)); + } } if (status & MCI_DATAEND) { + mmci_dma_data_end(host); mmci_stop_data(host); if (!data->stop) { @@ -623,6 +816,7 @@ 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; @@ -723,6 +917,8 @@ static int __devinit mmci_probe(struct amba_device *dev, struct amba_id *id) goto err_gpio_wp; } + mmci_setup_dma(host); + ret = request_irq(dev->irq[0], mmci_irq, IRQF_SHARED, DRIVER_NAME " (cmd)", host); if (ret) goto unmap; @@ -738,9 +934,13 @@ static int __devinit mmci_probe(struct amba_device *dev, struct amba_id *id) mmc_add_host(mmc); - dev_info(&dev->dev, "%s: MMCI rev %x cfg %02x at 0x%016llx irq %d,%d\n", - mmc_hostname(mmc), amba_rev(dev), amba_config(dev), - (unsigned long long)dev->res.start, dev->irq[0], dev->irq[1]); + dev_info(&dev->dev, "%s: MMCI/PL180 manf %x rev %x cfg %02x at 0x%016llx\n", + mmc_hostname(mmc), amba_manf(dev), amba_rev(dev), amba_config(dev), + (unsigned long long)dev->res.start); + dev_info(&dev->dev, "IRQ %d, %d (pio), DMA RX %s, DMA TX %s\n", + dev->irq[0], dev->irq[1], + host->dma_rx_channel ? dma_chan_name(host->dma_rx_channel) : "NOT USED", + host->dma_tx_channel ? dma_chan_name(host->dma_tx_channel) : "NOT USED"); init_timer(&host->timer); host->timer.data = (unsigned long)host; @@ -751,6 +951,7 @@ static int __devinit mmci_probe(struct amba_device *dev, struct amba_id *id) return 0; irq0_free: + mmci_disable_dma(host); free_irq(dev->irq[0], host); unmap: if (host->gpio_wp != -ENOSYS) @@ -791,6 +992,7 @@ static int __devexit mmci_remove(struct amba_device *dev) writel(0, host->base + MMCICOMMAND); writel(0, host->base + MMCIDATACTRL); + mmci_disable_dma(host); free_irq(dev->irq[0], host); free_irq(dev->irq[1], host); diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h index d77062e..d58ab0a 100644 --- a/drivers/mmc/host/mmci.h +++ b/drivers/mmc/host/mmci.h @@ -139,7 +139,6 @@ * The size of the FIFO in bytes. */ #define MCI_FIFOSIZE (16*4) - #define MCI_FIFOHALFSIZE (MCI_FIFOSIZE / 2) #define NR_SG 16 @@ -147,6 +146,7 @@ struct clk; struct mmci_host { + phys_addr_t phybase; void __iomem *base; struct mmc_request *mrq; struct mmc_command *cmd; @@ -177,7 +177,12 @@ struct mmci_host { struct scatterlist *sg_ptr; unsigned int sg_off; unsigned int size; + struct regulator *vcc; + /* DMA stuff */ + struct dma_chan *dma_rx_channel; + struct dma_chan *dma_tx_channel; + struct dma_async_tx_descriptor *dma_desc; }; static inline void mmci_init_sg(struct mmci_host *host, struct mmc_data *data) diff --git a/include/linux/amba/mmci.h b/include/linux/amba/mmci.h index 7e466fe..f2ca60f 100644 --- a/include/linux/amba/mmci.h +++ b/include/linux/amba/mmci.h @@ -6,6 +6,8 @@ #include +/* Just some dummy forwarding */ +struct dma_chan; /** * struct mmci_platform_data - platform configuration for the MMCI * (also known as PL180) block. @@ -25,6 +27,17 @@ * @gpio_cd: read this GPIO pin to detect card insertion * @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; @@ -34,6 +47,9 @@ struct mmci_platform_data { int gpio_wp; int gpio_cd; unsigned long capabilities; + bool (*dma_filter)(struct dma_chan *chan, void *filter_param); + void *dma_rx_param; + void *dma_tx_param; }; #endif -- 1.6.3.3