From 311f3ac76826bfd8ed6213ded91ec947df164def Mon Sep 17 00:00:00 2001 From: Guennadi Liakhovetski Date: Wed, 19 May 2010 18:34:22 +0000 Subject: [PATCH] mmc: add DMA support to tmio_mmc driver, when used on SuperH SDHI controllers on SuperH, served by the tmio_mmc driver, can use slave DMA for data transfer. This patch adds support for the dmaengine API to the tmio_mmc driver. Signed-off-by: Guennadi Liakhovetski Acked-by: Ian Molton Signed-off-by: Paul Mundt --- drivers/mfd/Kconfig | 6 + drivers/mmc/host/tmio_mmc.c | 359 +++++++++++++++++++++++++++++++++--- drivers/mmc/host/tmio_mmc.h | 13 ++ 3 files changed, 348 insertions(+), 30 deletions(-) diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig index de3e74cde51..3c6a9860dd9 100644 --- a/drivers/mfd/Kconfig +++ b/drivers/mfd/Kconfig @@ -49,6 +49,7 @@ config MFD_SH_MOBILE_SDHI bool "Support for SuperH Mobile SDHI" depends on SUPERH || ARCH_SHMOBILE select MFD_CORE + select TMIO_MMC_DMA ---help--- This driver supports the SDHI hardware block found in many SuperH Mobile SoCs. @@ -162,6 +163,11 @@ config MFD_TMIO bool default n +config TMIO_MMC_DMA + bool + select DMA_ENGINE + select DMADEVICES + config MFD_T7L66XB bool "Support Toshiba T7L66XB" depends on ARM && HAVE_CLK diff --git a/drivers/mmc/host/tmio_mmc.c b/drivers/mmc/host/tmio_mmc.c index b2b577f6afd..3ecd41875fa 100644 --- a/drivers/mmc/host/tmio_mmc.c +++ b/drivers/mmc/host/tmio_mmc.c @@ -29,6 +29,7 @@ #include #include #include +#include #include #include #include @@ -131,8 +132,8 @@ tmio_mmc_start_command(struct tmio_mmc_host *host, struct mmc_command *cmd) host->cmd = cmd; -/* FIXME - this seems to be ok comented out but the spec suggest this bit should - * be set when issuing app commands. +/* FIXME - this seems to be ok commented out but the spec suggest this bit + * should be set when issuing app commands. * if(cmd->flags & MMC_FLAG_ACMD) * c |= APP_CMD; */ @@ -155,12 +156,12 @@ tmio_mmc_start_command(struct tmio_mmc_host *host, struct mmc_command *cmd) return 0; } -/* This chip always returns (at least?) as much data as you ask for. +/* + * This chip always returns (at least?) as much data as you ask for. * I'm unsure what happens if you ask for less than a block. This should be * looked into to ensure that a funny length read doesnt hose the controller. - * */ -static inline void tmio_mmc_pio_irq(struct tmio_mmc_host *host) +static void tmio_mmc_pio_irq(struct tmio_mmc_host *host) { struct mmc_data *data = host->data; unsigned short *buf; @@ -180,7 +181,7 @@ static inline void tmio_mmc_pio_irq(struct tmio_mmc_host *host) count = data->blksz; pr_debug("count: %08x offset: %08x flags %08x\n", - count, host->sg_off, data->flags); + count, host->sg_off, data->flags); /* Transfer the data */ if (data->flags & MMC_DATA_READ) @@ -198,7 +199,7 @@ static inline void tmio_mmc_pio_irq(struct tmio_mmc_host *host) return; } -static inline void tmio_mmc_data_irq(struct tmio_mmc_host *host) +static void tmio_mmc_do_data_irq(struct tmio_mmc_host *host) { struct mmc_data *data = host->data; struct mmc_command *stop; @@ -206,7 +207,7 @@ static inline void tmio_mmc_data_irq(struct tmio_mmc_host *host) host->data = NULL; if (!data) { - pr_debug("Spurious data end IRQ\n"); + dev_warn(&host->pdev->dev, "Spurious data end IRQ\n"); return; } stop = data->stop; @@ -219,7 +220,8 @@ static inline void tmio_mmc_data_irq(struct tmio_mmc_host *host) pr_debug("Completed data request\n"); - /*FIXME - other drivers allow an optional stop command of any given type + /* + * FIXME: other drivers allow an optional stop command of any given type * which we dont do, as the chip can auto generate them. * Perhaps we can be smarter about when to use auto CMD12 and * only issue the auto request when we know this is the desired @@ -227,10 +229,17 @@ static inline void tmio_mmc_data_irq(struct tmio_mmc_host *host) * upper layers expect. For now, we do what works. */ - if (data->flags & MMC_DATA_READ) - disable_mmc_irqs(host, TMIO_MASK_READOP); - else - disable_mmc_irqs(host, TMIO_MASK_WRITEOP); + if (data->flags & MMC_DATA_READ) { + if (!host->chan_rx) + disable_mmc_irqs(host, TMIO_MASK_READOP); + dev_dbg(&host->pdev->dev, "Complete Rx request %p\n", + host->mrq); + } else { + if (!host->chan_tx) + disable_mmc_irqs(host, TMIO_MASK_WRITEOP); + dev_dbg(&host->pdev->dev, "Complete Tx request %p\n", + host->mrq); + } if (stop) { if (stop->opcode == 12 && !stop->arg) @@ -242,7 +251,35 @@ static inline void tmio_mmc_data_irq(struct tmio_mmc_host *host) tmio_mmc_finish_request(host); } -static inline void tmio_mmc_cmd_irq(struct tmio_mmc_host *host, +static void tmio_mmc_data_irq(struct tmio_mmc_host *host) +{ + struct mmc_data *data = host->data; + + if (!data) + return; + + if (host->chan_tx && (data->flags & MMC_DATA_WRITE)) { + /* + * Has all data been written out yet? Testing on SuperH showed, + * that in most cases the first interrupt comes already with the + * BUSY status bit clear, but on some operations, like mount or + * in the beginning of a write / sync / umount, there is one + * DATAEND interrupt with the BUSY bit set, in this cases + * waiting for one more interrupt fixes the problem. + */ + if (!(sd_ctrl_read32(host, CTL_STATUS) & TMIO_STAT_CMD_BUSY)) { + disable_mmc_irqs(host, TMIO_STAT_DATAEND); + tasklet_schedule(&host->dma_complete); + } + } else if (host->chan_rx && (data->flags & MMC_DATA_READ)) { + disable_mmc_irqs(host, TMIO_STAT_DATAEND); + tasklet_schedule(&host->dma_complete); + } else { + tmio_mmc_do_data_irq(host); + } +} + +static void tmio_mmc_cmd_irq(struct tmio_mmc_host *host, unsigned int stat) { struct mmc_command *cmd = host->cmd; @@ -282,10 +319,16 @@ static inline void tmio_mmc_cmd_irq(struct tmio_mmc_host *host, * If theres no data or we encountered an error, finish now. */ if (host->data && !cmd->error) { - if (host->data->flags & MMC_DATA_READ) - enable_mmc_irqs(host, TMIO_MASK_READOP); - else - enable_mmc_irqs(host, TMIO_MASK_WRITEOP); + if (host->data->flags & MMC_DATA_READ) { + if (!host->chan_rx) + enable_mmc_irqs(host, TMIO_MASK_READOP); + } else { + struct dma_chan *chan = host->chan_tx; + if (!chan) + enable_mmc_irqs(host, TMIO_MASK_WRITEOP); + else + tasklet_schedule(&host->dma_issue); + } } else { tmio_mmc_finish_request(host); } @@ -293,7 +336,6 @@ static inline void tmio_mmc_cmd_irq(struct tmio_mmc_host *host, return; } - static irqreturn_t tmio_mmc_irq(int irq, void *devid) { struct tmio_mmc_host *host = devid; @@ -311,7 +353,7 @@ static irqreturn_t tmio_mmc_irq(int irq, void *devid) if (!ireg) { disable_mmc_irqs(host, status & ~irq_mask); - pr_debug("tmio_mmc: Spurious irq, disabling! " + pr_warning("tmio_mmc: Spurious irq, disabling! " "0x%08x 0x%08x 0x%08x\n", status, irq_mask, ireg); pr_debug_status(status); @@ -363,16 +405,265 @@ out: return IRQ_HANDLED; } +#ifdef CONFIG_TMIO_MMC_DMA +static void tmio_mmc_enable_dma(struct tmio_mmc_host *host, bool enable) +{ +#if defined(CONFIG_SUPERH) || defined(CONFIG_ARCH_SHMOBILE) + /* Switch DMA mode on or off - SuperH specific? */ + sd_ctrl_write16(host, 0xd8, enable ? 2 : 0); +#endif +} + +static void tmio_dma_complete(void *arg) +{ + struct tmio_mmc_host *host = arg; + + dev_dbg(&host->pdev->dev, "Command completed\n"); + + if (!host->data) + dev_warn(&host->pdev->dev, "NULL data in DMA completion!\n"); + else + enable_mmc_irqs(host, TMIO_STAT_DATAEND); +} + +static int tmio_mmc_start_dma_rx(struct tmio_mmc_host *host) +{ + struct scatterlist *sg = host->sg_ptr; + struct dma_async_tx_descriptor *desc = NULL; + struct dma_chan *chan = host->chan_rx; + int ret; + + ret = dma_map_sg(&host->pdev->dev, sg, host->sg_len, DMA_FROM_DEVICE); + if (ret > 0) { + host->dma_sglen = ret; + desc = chan->device->device_prep_slave_sg(chan, sg, ret, + DMA_FROM_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + } + + if (desc) { + host->desc = desc; + desc->callback = tmio_dma_complete; + desc->callback_param = host; + host->cookie = desc->tx_submit(desc); + if (host->cookie < 0) { + host->desc = NULL; + ret = host->cookie; + } else { + chan->device->device_issue_pending(chan); + } + } + dev_dbg(&host->pdev->dev, "%s(): mapped %d -> %d, cookie %d, rq %p\n", + __func__, host->sg_len, ret, host->cookie, host->mrq); + + if (!host->desc) { + /* DMA failed, fall back to PIO */ + if (ret >= 0) + ret = -EIO; + host->chan_rx = NULL; + dma_release_channel(chan); + /* Free the Tx channel too */ + chan = host->chan_tx; + if (chan) { + host->chan_tx = NULL; + dma_release_channel(chan); + } + dev_warn(&host->pdev->dev, + "DMA failed: %d, falling back to PIO\n", ret); + tmio_mmc_enable_dma(host, false); + reset(host); + /* Fail this request, let above layers recover */ + host->mrq->cmd->error = ret; + tmio_mmc_finish_request(host); + } + + dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d, sg[%d]\n", __func__, + desc, host->cookie, host->sg_len); + + return ret > 0 ? 0 : ret; +} + +static int tmio_mmc_start_dma_tx(struct tmio_mmc_host *host) +{ + struct scatterlist *sg = host->sg_ptr; + struct dma_async_tx_descriptor *desc = NULL; + struct dma_chan *chan = host->chan_tx; + int ret; + + ret = dma_map_sg(&host->pdev->dev, sg, host->sg_len, DMA_TO_DEVICE); + if (ret > 0) { + host->dma_sglen = ret; + desc = chan->device->device_prep_slave_sg(chan, sg, ret, + DMA_TO_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + } + + if (desc) { + host->desc = desc; + desc->callback = tmio_dma_complete; + desc->callback_param = host; + host->cookie = desc->tx_submit(desc); + if (host->cookie < 0) { + host->desc = NULL; + ret = host->cookie; + } + } + dev_dbg(&host->pdev->dev, "%s(): mapped %d -> %d, cookie %d, rq %p\n", + __func__, host->sg_len, ret, host->cookie, host->mrq); + + if (!host->desc) { + /* DMA failed, fall back to PIO */ + if (ret >= 0) + ret = -EIO; + host->chan_tx = NULL; + dma_release_channel(chan); + /* Free the Rx channel too */ + chan = host->chan_rx; + if (chan) { + host->chan_rx = NULL; + dma_release_channel(chan); + } + dev_warn(&host->pdev->dev, + "DMA failed: %d, falling back to PIO\n", ret); + tmio_mmc_enable_dma(host, false); + reset(host); + /* Fail this request, let above layers recover */ + host->mrq->cmd->error = ret; + tmio_mmc_finish_request(host); + } + + dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d\n", __func__, + desc, host->cookie); + + return ret > 0 ? 0 : ret; +} + +static int tmio_mmc_start_dma(struct tmio_mmc_host *host, + struct mmc_data *data) +{ + if (data->flags & MMC_DATA_READ) { + if (host->chan_rx) + return tmio_mmc_start_dma_rx(host); + } else { + if (host->chan_tx) + return tmio_mmc_start_dma_tx(host); + } + + return 0; +} + +static void tmio_issue_tasklet_fn(unsigned long priv) +{ + struct tmio_mmc_host *host = (struct tmio_mmc_host *)priv; + struct dma_chan *chan = host->chan_tx; + + chan->device->device_issue_pending(chan); +} + +static void tmio_tasklet_fn(unsigned long arg) +{ + struct tmio_mmc_host *host = (struct tmio_mmc_host *)arg; + + if (host->data->flags & MMC_DATA_READ) + dma_unmap_sg(&host->pdev->dev, host->sg_ptr, host->dma_sglen, + DMA_FROM_DEVICE); + else + dma_unmap_sg(&host->pdev->dev, host->sg_ptr, host->dma_sglen, + DMA_TO_DEVICE); + + tmio_mmc_do_data_irq(host); +} + +/* It might be necessary to make filter MFD specific */ +static bool tmio_mmc_filter(struct dma_chan *chan, void *arg) +{ + dev_dbg(chan->device->dev, "%s: slave data %p\n", __func__, arg); + chan->private = arg; + return true; +} + +static void tmio_mmc_request_dma(struct tmio_mmc_host *host, + struct tmio_mmc_data *pdata) +{ + host->cookie = -EINVAL; + host->desc = NULL; + + /* We can only either use DMA for both Tx and Rx or not use it at all */ + if (pdata->dma) { + dma_cap_mask_t mask; + + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + + host->chan_tx = dma_request_channel(mask, tmio_mmc_filter, + pdata->dma->chan_priv_tx); + dev_dbg(&host->pdev->dev, "%s: TX: got channel %p\n", __func__, + host->chan_tx); + + if (!host->chan_tx) + return; + + host->chan_rx = dma_request_channel(mask, tmio_mmc_filter, + pdata->dma->chan_priv_rx); + dev_dbg(&host->pdev->dev, "%s: RX: got channel %p\n", __func__, + host->chan_rx); + + if (!host->chan_rx) { + dma_release_channel(host->chan_tx); + host->chan_tx = NULL; + return; + } + + tasklet_init(&host->dma_complete, tmio_tasklet_fn, (unsigned long)host); + tasklet_init(&host->dma_issue, tmio_issue_tasklet_fn, (unsigned long)host); + + tmio_mmc_enable_dma(host, true); + } +} + +static void tmio_mmc_release_dma(struct tmio_mmc_host *host) +{ + if (host->chan_tx) { + struct dma_chan *chan = host->chan_tx; + host->chan_tx = NULL; + dma_release_channel(chan); + } + if (host->chan_rx) { + struct dma_chan *chan = host->chan_rx; + host->chan_rx = NULL; + dma_release_channel(chan); + } + + host->cookie = -EINVAL; + host->desc = NULL; +} +#else +static int tmio_mmc_start_dma(struct tmio_mmc_host *host, + struct mmc_data *data) +{ + return 0; +} + +static void tmio_mmc_request_dma(struct tmio_mmc_host *host, + struct tmio_mmc_data *pdata) +{ + host->chan_tx = NULL; + host->chan_rx = NULL; +} + +static void tmio_mmc_release_dma(struct tmio_mmc_host *host) +{ +} +#endif + static int tmio_mmc_start_data(struct tmio_mmc_host *host, struct mmc_data *data) { pr_debug("setup data transfer: blocksize %08x nr_blocks %d\n", - data->blksz, data->blocks); + data->blksz, data->blocks); /* Hardware cannot perform 1 and 2 byte requests in 4 bit mode */ if (data->blksz < 4 && host->mmc->ios.bus_width == MMC_BUS_WIDTH_4) { - printk(KERN_ERR "%s: %d byte block unsupported in 4 bit mode\n", - mmc_hostname(host->mmc), data->blksz); + pr_err("%s: %d byte block unsupported in 4 bit mode\n", + mmc_hostname(host->mmc), data->blksz); return -EINVAL; } @@ -383,7 +674,7 @@ static int tmio_mmc_start_data(struct tmio_mmc_host *host, sd_ctrl_write16(host, CTL_SD_XFER_LEN, data->blksz); sd_ctrl_write16(host, CTL_XFER_BLK_COUNT, data->blocks); - return 0; + return tmio_mmc_start_dma(host, data); } /* Process requests from the MMC layer */ @@ -404,7 +695,6 @@ static void tmio_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq) } ret = tmio_mmc_start_command(host, mrq->cmd); - if (!ret) return; @@ -459,10 +749,10 @@ static int tmio_mmc_get_ro(struct mmc_host *mmc) { struct tmio_mmc_host *host = mmc_priv(mmc); - return (sd_ctrl_read16(host, CTL_STATUS) & TMIO_STAT_WRPROTECT) ? 0 : 1; + return (sd_ctrl_read32(host, CTL_STATUS) & TMIO_STAT_WRPROTECT) ? 0 : 1; } -static struct mmc_host_ops tmio_mmc_ops = { +static const struct mmc_host_ops tmio_mmc_ops = { .request = tmio_mmc_request, .set_ios = tmio_mmc_set_ios, .get_ro = tmio_mmc_get_ro, @@ -515,6 +805,7 @@ static int __devinit tmio_mmc_probe(struct platform_device *dev) struct tmio_mmc_host *host; struct mmc_host *mmc; int ret = -EINVAL; + u32 irq_mask = TMIO_MASK_CMD; if (dev->num_resources != 2) goto out; @@ -578,13 +869,20 @@ static int __devinit tmio_mmc_probe(struct platform_device *dev) if (ret) goto cell_disable; + /* See if we also get DMA */ + tmio_mmc_request_dma(host, pdata); + mmc_add_host(mmc); - printk(KERN_INFO "%s at 0x%08lx irq %d\n", mmc_hostname(host->mmc), - (unsigned long)host->ctl, host->irq); + pr_info("%s at 0x%08lx irq %d\n", mmc_hostname(host->mmc), + (unsigned long)host->ctl, host->irq); /* Unmask the IRQs we want to know about */ - enable_mmc_irqs(host, TMIO_MASK_IRQ); + if (!host->chan_rx) + irq_mask |= TMIO_MASK_READOP; + if (!host->chan_tx) + irq_mask |= TMIO_MASK_WRITEOP; + enable_mmc_irqs(host, irq_mask); return 0; @@ -609,6 +907,7 @@ static int __devexit tmio_mmc_remove(struct platform_device *dev) if (mmc) { struct tmio_mmc_host *host = mmc_priv(mmc); mmc_remove_host(mmc); + tmio_mmc_release_dma(host); free_irq(host->irq, host); if (cell->disable) cell->disable(dev); diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h index dafecfbcd91..64f7d5dfc10 100644 --- a/drivers/mmc/host/tmio_mmc.h +++ b/drivers/mmc/host/tmio_mmc.h @@ -10,6 +10,8 @@ */ #include +#include +#include #define CTL_SD_CMD 0x00 #define CTL_ARG_REG 0x04 @@ -106,6 +108,17 @@ struct tmio_mmc_host { unsigned int sg_off; struct platform_device *pdev; + + /* DMA support */ + struct dma_chan *chan_rx; + struct dma_chan *chan_tx; + struct tasklet_struct dma_complete; + struct tasklet_struct dma_issue; +#ifdef CONFIG_TMIO_MMC_DMA + struct dma_async_tx_descriptor *desc; + unsigned int dma_sglen; + dma_cookie_t cookie; +#endif }; #include -- 2.20.1