mmc: omap_hsmmc: add support for pre_req and post_req

pre_req() runs dma_map_sg(), post_req() runs dma_unmap_sg.  If not calling
pre_req() before omap_hsmmc_request(), dma_map_sg will be issued before
starting the transfer.  It is optional to use pre_req().  If issuing
pre_req(), post_req() must be called as well.

Signed-off-by: Per Forlin <per.forlin@linaro.org>
Reviewed-by: Venkatraman S <svenkatr@ti.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index dedf3da..b0c6910 100644 (file)
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -141,6 +141,11 @@
 #define OMAP_HSMMC_WRITE(base, reg, val) \
        __raw_writel((val), (base) + OMAP_HSMMC_##reg)
 
+struct omap_hsmmc_next {
+       unsigned int    dma_len;
+       s32             cookie;
+};
+
 struct omap_hsmmc_host {
        struct  device          *dev;
        struct  mmc_host        *mmc;
@@ -184,6 +189,7 @@ struct omap_hsmmc_host {
        int                     reqs_blocked;
        int                     use_reg;
        int                     req_in_progress;
+       struct omap_hsmmc_next  next_data;
 
        struct  omap_mmc_platform_data  *pdata;
 };
@@ -1346,8 +1352,9 @@ static void omap_hsmmc_dma_cb(int lch, u16 ch_status, void *cb_data)
                return;
        }
 
-       dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
-               omap_hsmmc_get_dma_dir(host, data));
+       if (!data->host_cookie)
+               dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
+                            omap_hsmmc_get_dma_dir(host, data));
 
        req_in_progress = host->req_in_progress;
        dma_ch = host->dma_ch;
@@ -1365,6 +1372,45 @@ static void omap_hsmmc_dma_cb(int lch, u16 ch_status, void *cb_data)
        }
 }
 
+static int omap_hsmmc_pre_dma_transfer(struct omap_hsmmc_host *host,
+                                      struct mmc_data *data,
+                                      struct omap_hsmmc_next *next)
+{
+       int dma_len;
+
+       if (!next && data->host_cookie &&
+           data->host_cookie != host->next_data.cookie) {
+               printk(KERN_WARNING "[%s] invalid cookie: data->host_cookie %d"
+                      " host->next_data.cookie %d\n",
+                      __func__, data->host_cookie, host->next_data.cookie);
+               data->host_cookie = 0;
+       }
+
+       /* Check if next job is already prepared */
+       if (next ||
+           (!next && data->host_cookie != host->next_data.cookie)) {
+               dma_len = dma_map_sg(mmc_dev(host->mmc), data->sg,
+                                    data->sg_len,
+                                    omap_hsmmc_get_dma_dir(host, data));
+
+       } else {
+               dma_len = host->next_data.dma_len;
+               host->next_data.dma_len = 0;
+       }
+
+
+       if (dma_len == 0)
+               return -EINVAL;
+
+       if (next) {
+               next->dma_len = dma_len;
+               data->host_cookie = ++next->cookie < 0 ? 1 : next->cookie;
+       } else
+               host->dma_len = dma_len;
+
+       return 0;
+}
+
 /*
  * Routine to configure and start DMA for the MMC card
  */
@@ -1398,9 +1444,10 @@ static int omap_hsmmc_start_dma_transfer(struct omap_hsmmc_host *host,
                        mmc_hostname(host->mmc), ret);
                return ret;
        }
+       ret = omap_hsmmc_pre_dma_transfer(host, data, NULL);
+       if (ret)
+               return ret;
 
-       host->dma_len = dma_map_sg(mmc_dev(host->mmc), data->sg,
-                       data->sg_len, omap_hsmmc_get_dma_dir(host, data));
        host->dma_ch = dma_ch;
        host->dma_sg_idx = 0;
 
@@ -1480,6 +1527,35 @@ omap_hsmmc_prepare_data(struct omap_hsmmc_host *host, struct mmc_request *req)
        return 0;
 }
 
+static void omap_hsmmc_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
+                               int err)
+{
+       struct omap_hsmmc_host *host = mmc_priv(mmc);
+       struct mmc_data *data = mrq->data;
+
+       if (host->use_dma) {
+               dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
+                            omap_hsmmc_get_dma_dir(host, data));
+               data->host_cookie = 0;
+       }
+}
+
+static void omap_hsmmc_pre_req(struct mmc_host *mmc, struct mmc_request *mrq,
+                              bool is_first_req)
+{
+       struct omap_hsmmc_host *host = mmc_priv(mmc);
+
+       if (mrq->data->host_cookie) {
+               mrq->data->host_cookie = 0;
+               return ;
+       }
+
+       if (host->use_dma)
+               if (omap_hsmmc_pre_dma_transfer(host, mrq->data,
+                                               &host->next_data))
+                       mrq->data->host_cookie = 0;
+}
+
 /*
  * Request function. for read/write operation
  */
@@ -1928,6 +2004,8 @@ static int omap_hsmmc_disable_fclk(struct mmc_host *mmc, int lazy)
 static const struct mmc_host_ops omap_hsmmc_ops = {
        .enable = omap_hsmmc_enable_fclk,
        .disable = omap_hsmmc_disable_fclk,
+       .post_req = omap_hsmmc_post_req,
+       .pre_req = omap_hsmmc_pre_req,
        .request = omap_hsmmc_request,
        .set_ios = omap_hsmmc_set_ios,
        .get_cd = omap_hsmmc_get_cd,
@@ -2077,6 +2155,7 @@ static int __init omap_hsmmc_probe(struct platform_device *pdev)
        host->mapbase   = res->start;
        host->base      = ioremap(host->mapbase, SZ_4K);
        host->power_mode = MMC_POWER_OFF;
+       host->next_data.cookie = 1;
 
        platform_set_drvdata(pdev, host);
        INIT_WORK(&host->mmc_carddetect_work, omap_hsmmc_detect);