From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bastian Hecht Date: Sun, 23 Sep 2012 12:01:22 +0000 Subject: [PATCH 1/2] mtd: sh_flctl: Setup and release DMA channels Message-Id: <1348401683-15698-1-git-send-email-hechtb@gmail.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-mtd@lists.infradead.org Cc: Magnus Damm , Guennadi Liakhovetski , linux-sh@vger.kernel.org The code probes if DMA channels can get allocated and tears them down at removal/failure if needed. Based on Guennadi Liakhovetski's code from the sh_mmcif driver. Signed-off-by: Bastian Hecht --- Based on l2-mtd with reverted commit e26c113b4130aefa1d8446602bb5b05cfd646bfe. drivers/mtd/nand/sh_flctl.c | 74 ++++++++++++++++++++++++++++++++++++++++++ include/linux/mtd/sh_flctl.h | 10 ++++++ 2 files changed, 84 insertions(+), 0 deletions(-) diff --git a/drivers/mtd/nand/sh_flctl.c b/drivers/mtd/nand/sh_flctl.c index 4fbfe96..2cf6871 100644 --- a/drivers/mtd/nand/sh_flctl.c +++ b/drivers/mtd/nand/sh_flctl.c @@ -856,6 +856,76 @@ static irqreturn_t flctl_handle_flste(int irq, void *dev_id) return IRQ_HANDLED; } +void flctl_setup_dma(struct sh_flctl *flctl) +{ + dma_cap_mask_t mask; + struct dma_slave_config cfg; + struct platform_device *pdev = flctl->pdev; + struct sh_flctl_platform_data *pdata = pdev->dev.platform_data; + int ret; + + if (!pdata) + return; + + if (pdata->slave_id_fifo0_tx <= 0 || pdata->slave_id_fifo0_rx <= 0) + return; + + /* We can only either use DMA for both Tx and Rx or not use it at all */ + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + + flctl->chan_fifo0_tx = dma_request_channel(mask, shdma_chan_filter, + (void *)pdata->slave_id_fifo0_tx); + dev_dbg(&pdev->dev, "%s: TX: got channel %p\n", __func__, + flctl->chan_fifo0_tx); + + if (!flctl->chan_fifo0_tx) + return; + + cfg.slave_id = pdata->slave_id_fifo0_tx; + cfg.direction = DMA_MEM_TO_DEV; + cfg.dst_addr = (dma_addr_t)FLDTFIFO(flctl); + cfg.src_addr = 0; + ret = dmaengine_slave_config(flctl->chan_fifo0_tx, &cfg); + if (ret < 0) + goto err; + + flctl->chan_fifo0_rx = dma_request_channel(mask, shdma_chan_filter, + (void *)pdata->slave_id_fifo0_rx); + dev_dbg(&pdev->dev, "%s: RX: got channel %p\n", __func__, + flctl->chan_fifo0_rx); + + if (!flctl->chan_fifo0_rx) + goto err; + + cfg.slave_id = pdata->slave_id_fifo0_rx; + cfg.direction = DMA_DEV_TO_MEM; + cfg.dst_addr = 0; + cfg.src_addr = (dma_addr_t)FLDTFIFO(flctl); + ret = dmaengine_slave_config(flctl->chan_fifo0_rx, &cfg); + if (ret < 0) + goto err; + + init_completion(&flctl->dma_complete); + + return; + +err: + flctl_release_dma(flctl); +} + +static void flctl_release_dma(struct sh_flctl *flctl) +{ + if (flctl->chan_fifo0_rx) { + dma_release_channel(flctl->chan_fifo0_rx); + flctl->chan_fifo0_rx = NULL; + } + if (flctl->chan_fifo0_tx) { + dma_release_channel(flctl->chan_fifo0_tx); + flctl->chan_fifo0_tx = NULL; + } +} + static int __devinit flctl_probe(struct platform_device *pdev) { struct resource *res; @@ -930,6 +1000,8 @@ static int __devinit flctl_probe(struct platform_device *pdev) pm_runtime_enable(&pdev->dev); pm_runtime_resume(&pdev->dev); + flctl_setup_dma(flctl); + ret = nand_scan_ident(flctl_mtd, 1, NULL); if (ret) goto err_chip; @@ -947,6 +1019,7 @@ static int __devinit flctl_probe(struct platform_device *pdev) return 0; err_chip: + flctl_release_dma(flctl); pm_runtime_disable(&pdev->dev); free_irq(irq, flctl); err_flste: @@ -960,6 +1033,7 @@ static int __devexit flctl_remove(struct platform_device *pdev) { struct sh_flctl *flctl = platform_get_drvdata(pdev); + flctl_release_dma(flctl); nand_release(&flctl->mtd); pm_runtime_disable(&pdev->dev); free_irq(platform_get_irq(pdev, 0), flctl); diff --git a/include/linux/mtd/sh_flctl.h b/include/linux/mtd/sh_flctl.h index 01e4b15..20d3f48 100644 --- a/include/linux/mtd/sh_flctl.h +++ b/include/linux/mtd/sh_flctl.h @@ -20,10 +20,12 @@ #ifndef __SH_FLCTL_H__ #define __SH_FLCTL_H__ +#include #include #include #include #include +#include /* FLCTL registers */ #define FLCMNCR(f) (f->reg + 0x0) @@ -161,6 +163,11 @@ struct sh_flctl { unsigned hwecc:1; /* Hardware ECC (0 = disabled, 1 = enabled) */ unsigned holden:1; /* Hardware has FLHOLDCR and HOLDEN is set */ unsigned qos_request:1; /* QoS request to prevent deep power shutdown */ + + /* DMA related objects */ + struct dma_chan *chan_fifo0_rx; + struct dma_chan *chan_fifo0_tx; + struct completion dma_complete; }; struct sh_flctl_platform_data { @@ -170,6 +177,9 @@ struct sh_flctl_platform_data { unsigned has_hwecc:1; unsigned use_holden:1; + + unsigned int slave_id_fifo0_tx; + unsigned int slave_id_fifo0_rx; }; static inline struct sh_flctl *mtd_to_flctl(struct mtd_info *mtdinfo) -- 1.7.5.4