[PATCH v3] s3cmci: port DMA code to dmaengine API

Vasily Khoruzhick
2014-06-23T11:31:45Z

On 1 June 2014 20:22:09 Vasily Khoruzhick wrote:
> Utilise new s3c24xx-dma dmaengine driver for DMA ops.
>
> Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
> ---
> v2: - Don't store async dma descriptor, it's not used
> - Request DMA channel via dma_request_slave_channel_compat() and use
> hardcoded DMA channel.
> - Add dependency on S3C24XX_DMAC (s3cmci uses filter function from it)
> v3: - Use 'depends' instead of 'select' in Kconfig
> - Drop useless controller registers reads from dma completion callback

Ping?

> drivers/mmc/host/Kconfig | 10 +--
> drivers/mmc/host/s3cmci.c | 180
> +++++++++++++--------------------------------- drivers/mmc/host/s3cmci.h |
> 4 +-
> 3 files changed, 52 insertions(+), 142 deletions(-)
>
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index 1384f67..0cd10e3 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -420,6 +420,7 @@ config MMC_SPI
> config MMC_S3C
> tristate "Samsung S3C SD/MMC Card Interface support"
> depends on ARCH_S3C24XX
> + depends on S3C24XX_DMAC
> help
> This selects a driver for the MCI interface found in
> Samsung's S3C2410, S3C2412, S3C2440, S3C2442 CPUs.
> @@ -457,15 +458,6 @@ config MMC_S3C_DMA
> working properly and needs to be debugged before this
> option is useful.
>
> -config MMC_S3C_PIODMA
> - bool "Support for both PIO and DMA"
> - help
> - Compile both the PIO and DMA transfer routines into the
> - driver and let the platform select at run-time which one
> - is best.
> -
> - See notes for the DMA option.
> -
> endchoice
>
> config MMC_SDRICOH_CS
> diff --git a/drivers/mmc/host/s3cmci.c b/drivers/mmc/host/s3cmci.c
> index f237826..0d115a8 100644
> --- a/drivers/mmc/host/s3cmci.c
> +++ b/drivers/mmc/host/s3cmci.c
> @@ -12,6 +12,7 @@
> */
>
> #include <linux/module.h>
> +#include <linux/dmaengine.h>
> #include <linux/dma-mapping.h>
> #include <linux/clk.h>
> #include <linux/mmc/host.h>
> @@ -27,6 +28,7 @@
> #include <mach/dma.h>
> #include <mach/gpio-samsung.h>
>
> +#include <linux/platform_data/dma-s3c24xx.h>
> #include <linux/platform_data/mmc-s3cmci.h>
>
> #include "s3cmci.h"
> @@ -140,10 +142,6 @@ static const int dbgmap_debug = dbg_err | dbg_debug;
> dev_dbg(&host->pdev->dev, args); \
> } while (0)
>
> -static struct s3c2410_dma_client s3cmci_dma_client = {
> - .name = "s3c-mci",
> -};
> -
> static void finalize_request(struct s3cmci_host *host);
> static void s3cmci_send_request(struct mmc_host *mmc);
> static void s3cmci_reset(struct s3cmci_host *host);
> @@ -256,25 +254,8 @@ static inline bool s3cmci_host_usedma(struct
> s3cmci_host *host) {
> #ifdef CONFIG_MMC_S3C_PIO
> return false;
> -#elif defined(CONFIG_MMC_S3C_DMA)
> +#else /* CONFIG_MMC_S3C_DMA */
> return true;
> -#else
> - return host->dodma;
> -#endif
> -}
> -
> -/**
> - * s3cmci_host_canpio - return true if host has pio code available
> - *
> - * Return true if the driver has been compiled with the PIO support code
> - * available.
> - */
> -static inline bool s3cmci_host_canpio(void)
> -{
> -#ifdef CONFIG_MMC_S3C_PIO
> - return true;
> -#else
> - return false;
> #endif
> }
>
> @@ -841,60 +822,24 @@ static irqreturn_t s3cmci_irq_cd(int irq, void
> *dev_id) return IRQ_HANDLED;
> }
>
> -static void s3cmci_dma_done_callback(struct s3c2410_dma_chan *dma_ch,
> - void *buf_id, int size,
> - enum s3c2410_dma_buffresult result)
> +static void s3cmci_dma_done_callback(void *arg)
> {
> - struct s3cmci_host *host = buf_id;
> + struct s3cmci_host *host = arg;
> unsigned long iflags;
> - u32 mci_csta, mci_dsta, mci_fsta, mci_dcnt;
> -
> - mci_csta = readl(host->base + S3C2410_SDICMDSTAT);
> - mci_dsta = readl(host->base + S3C2410_SDIDSTA);
> - mci_fsta = readl(host->base + S3C2410_SDIFSTA);
> - mci_dcnt = readl(host->base + S3C2410_SDIDCNT);
>
> BUG_ON(!host->mrq);
> BUG_ON(!host->mrq->data);
> - BUG_ON(!host->dmatogo);
>
> spin_lock_irqsave(&host->complete_lock, iflags);
>
> - if (result != S3C2410_RES_OK) {
> - dbg(host, dbg_fail, "DMA FAILED: csta=0x%08x dsta=0x%08x "
> - "fsta=0x%08x dcnt:0x%08x result:0x%08x toGo:%u\n",
> - mci_csta, mci_dsta, mci_fsta,
> - mci_dcnt, result, host->dmatogo);
> -
> - goto fail_request;
> - }
> -
> - host->dmatogo--;
> - if (host->dmatogo) {
> - dbg(host, dbg_dma, "DMA DONE Size:%i DSTA:[%08x] "
> - "DCNT:[%08x] toGo:%u\n",
> - size, mci_dsta, mci_dcnt, host->dmatogo);
> -
> - goto out;
> - }
> -
> - dbg(host, dbg_dma, "DMA FINISHED Size:%i DSTA:%08x DCNT:%08x\n",
> - size, mci_dsta, mci_dcnt);
> + dbg(host, dbg_dma, "DMA FINISHED\n");
>
> host->dma_complete = 1;
> host->complete_what = COMPLETION_FINALIZE;
>
> -out:
> tasklet_schedule(&host->pio_tasklet);
> spin_unlock_irqrestore(&host->complete_lock, iflags);
> - return;
>
> -fail_request:
> - host->mrq->data->error = -EINVAL;
> - host->complete_what = COMPLETION_FINALIZE;
> - clear_imask(host);
> -
> - goto out;
> }
>
> static void finalize_request(struct s3cmci_host *host)
> @@ -966,7 +911,7 @@ static void finalize_request(struct s3cmci_host *host)
> * DMA channel and the fifo to clear out any garbage. */
> if (mrq->data->error != 0) {
> if (s3cmci_host_usedma(host))
> - s3c2410_dma_ctrl(host->dma, S3C2410_DMAOP_FLUSH);
> + dmaengine_terminate_all(host->dma);
>
> if (host->is2440) {
> /* Clear failure register and reset fifo. */
> @@ -992,29 +937,6 @@ request_done:
> mmc_request_done(host->mmc, mrq);
> }
>
> -static void s3cmci_dma_setup(struct s3cmci_host *host,
> - enum dma_data_direction source)
> -{
> - static enum dma_data_direction last_source = -1;
> - static int setup_ok;
> -
> - if (last_source == source)
> - return;
> -
> - last_source = source;
> -
> - s3c2410_dma_devconfig(host->dma, source,
> - host->mem->start + host->sdidata);
> -
> - if (!setup_ok) {
> - s3c2410_dma_config(host->dma, 4);
> - s3c2410_dma_set_buffdone_fn(host->dma,
> - s3cmci_dma_done_callback);
> - s3c2410_dma_setflags(host->dma, S3C2410_DMAF_AUTOSTART);
> - setup_ok = 1;
> - }
> -}
> -
> static void s3cmci_send_command(struct s3cmci_host *host,
> struct mmc_command *cmd)
> {
> @@ -1162,43 +1084,45 @@ static int s3cmci_prepare_pio(struct s3cmci_host
> *host, struct mmc_data *data)
>
> static int s3cmci_prepare_dma(struct s3cmci_host *host, struct mmc_data
> *data) {
> - int dma_len, i;
> int rw = data->flags & MMC_DATA_WRITE;
> + struct dma_async_tx_descriptor *desc;
> + struct dma_slave_config conf = {
> + .src_addr = host->mem->start + host->sdidata,
> + .dst_addr = host->mem->start + host->sdidata,
> + .src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
> + .dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES,
> + };
>
> BUG_ON((data->flags & BOTH_DIR) == BOTH_DIR);
>
> - s3cmci_dma_setup(host, rw ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
> - s3c2410_dma_ctrl(host->dma, S3C2410_DMAOP_FLUSH);
> -
> - dma_len = dma_map_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
> - rw ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
> -
> - if (dma_len == 0)
> - return -ENOMEM;
> -
> - host->dma_complete = 0;
> - host->dmatogo = dma_len;
> -
> - for (i = 0; i < dma_len; i++) {
> - int res;
> -
> - dbg(host, dbg_dma, "enqueue %i: %08x@%u\n", i,
> - sg_dma_address(&data->sg[i]),
> - sg_dma_len(&data->sg[i]));
> + /* Restore prescaler value */
> + writel(host->prescaler, host->base + S3C2410_SDIPRE);
>
> - res = s3c2410_dma_enqueue(host->dma, host,
> - sg_dma_address(&data->sg[i]),
> - sg_dma_len(&data->sg[i]));
> + if (!rw)
> + conf.direction = DMA_DEV_TO_MEM;
> + else
> + conf.direction = DMA_MEM_TO_DEV;
>
> - if (res) {
> - s3c2410_dma_ctrl(host->dma, S3C2410_DMAOP_FLUSH);
> - return -EBUSY;
> - }
> - }
> + dma_map_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
> + rw ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
>
> - s3c2410_dma_ctrl(host->dma, S3C2410_DMAOP_START);
> + dmaengine_slave_config(host->dma, &conf);
> + desc = dmaengine_prep_slave_sg(host->dma, data->sg, data->sg_len,
> + conf.direction,
> + DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
> + if (!desc)
> + goto unmap_exit;
> + desc->callback = s3cmci_dma_done_callback;
> + desc->callback_param = host;
> + dmaengine_submit(desc);
> + dma_async_issue_pending(host->dma);
>
> return 0;
> +
> +unmap_exit:
> + dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
> + rw ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
> + return -ENOMEM;
> }
>
> static void s3cmci_send_request(struct mmc_host *mmc)
> @@ -1676,10 +1600,6 @@ static int s3cmci_probe(struct platform_device *pdev)
> host->complete_what = COMPLETION_NONE;
> host->pio_active = XFER_NONE;
>
> -#ifdef CONFIG_MMC_S3C_PIODMA
> - host->dodma = host->pdata->use_dma;
> -#endif
> -
> host->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> if (!host->mem) {
> dev_err(&pdev->dev,
> @@ -1765,17 +1685,17 @@ static int s3cmci_probe(struct platform_device
> *pdev) /* depending on the dma state, get a dma channel to use. */
>
> if (s3cmci_host_usedma(host)) {
> - host->dma = s3c2410_dma_request(DMACH_SDI, &s3cmci_dma_client,
> - host);
> - if (host->dma < 0) {
> + dma_cap_mask_t mask;
> +
> + dma_cap_zero(mask);
> + dma_cap_set(DMA_SLAVE, mask);
> +
> + host->dma = dma_request_slave_channel_compat(mask,
> + s3c24xx_dma_filter, (void *)DMACH_SDI, &pdev->dev, "rx-tx");
> + if (!host->dma) {
> dev_err(&pdev->dev, "cannot get DMA channel.\n");
> - if (!s3cmci_host_canpio()) {
> - ret = -EBUSY;
> - goto probe_free_gpio_wp;
> - } else {
> - dev_warn(&pdev->dev, "falling back to PIO.\n");
> - host->dodma = 0;
> - }
> + ret = -EBUSY;
> + goto probe_free_gpio_wp;
> }
> }
>
> @@ -1816,7 +1736,7 @@ static int s3cmci_probe(struct platform_device *pdev)
> mmc->max_segs = 128;
>
> dbg(host, dbg_debug,
> - "probe: mode:%s mapped mci_base:%p irq:%u irq_cd:%u dma:%u.\n",
> + "probe: mode:%s mapped mci_base:%p irq:%u irq_cd:%u dma:%p.\n",
> (host->is2440?"2440":""),
> host->base, host->irq, host->irq_cd, host->dma);
>
> @@ -1852,7 +1772,7 @@ static int s3cmci_probe(struct platform_device *pdev)
>
> probe_free_dma:
> if (s3cmci_host_usedma(host))
> - s3c2410_dma_free(host->dma, &s3cmci_dma_client);
> + dma_release_channel(host->dma);
>
> probe_free_gpio_wp:
> if (!host->pdata->no_wprotect)
> @@ -1914,7 +1834,7 @@ static int s3cmci_remove(struct platform_device *pdev)
> tasklet_disable(&host->pio_tasklet);
>
> if (s3cmci_host_usedma(host))
> - s3c2410_dma_free(host->dma, &s3cmci_dma_client);
> + dma_release_channel(host->dma);
>
> free_irq(host->irq, host);
>
> diff --git a/drivers/mmc/host/s3cmci.h b/drivers/mmc/host/s3cmci.h
> index c76b53d..cc2e46c 100644
> --- a/drivers/mmc/host/s3cmci.h
> +++ b/drivers/mmc/host/s3cmci.h
> @@ -26,7 +26,7 @@ struct s3cmci_host {
> void __iomem *base;
> int irq;
> int irq_cd;
> - int dma;
> + struct dma_chan *dma;
>
> unsigned long clk_rate;
> unsigned long clk_div;
> @@ -36,8 +36,6 @@ struct s3cmci_host {
> int is2440;
> unsigned sdiimsk;
> unsigned sdidata;
> - int dodma;
> - int dmatogo;
>
> bool irq_disabled;
> bool irq_enabled;
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