mmc: sh_mmcif: rework dma channel handling

When compiling the sh_mmcif driver for ARM64, we currently
get a harmless build warning:

../drivers/mmc/host/sh_mmcif.c: In function 'sh_mmcif_request_dma_one':
../drivers/mmc/host/sh_mmcif.c:417:4: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
    (void *)pdata->slave_id_tx :
    ^
../drivers/mmc/host/sh_mmcif.c:418:4: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
    (void *)pdata->slave_id_rx;

This could be worked around by adding another cast to uintptr_t, but
I decided to simplify the code a little more to avoid that. This
splits out the platform data using code into a separate function
and builds that only for CONFIG_SUPERH. This part still has a typecast
but does not need a second one. The SH platform code could be further
modified to pass a pointer directly as we do on other architectures
when we have a filter function.

The normal case is simplified further and now just calls
dma_request_slave_channel() directly without going through the
compat handling.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

1 files changed, 38 insertions, 46 deletions

diff --git a/drivers/mmc/host/sh_mmcif.c b/drivers/mmc/host/sh_mmcif.c
index ad9ffea7d659..1ca8a1359cbc 100644
--- a/drivers/mmc/host/sh_mmcif.c
+++ b/drivers/mmc/host/sh_mmcif.c
@@ -397,38 +397,26 @@ static void sh_mmcif_start_dma_tx(struct sh_mmcif_host *host)
 }
 
 static struct dma_chan *
-sh_mmcif_request_dma_one(struct sh_mmcif_host *host,
-                         struct sh_mmcif_plat_data *pdata,
-                         enum dma_transfer_direction direction)
+sh_mmcif_request_dma_pdata(struct sh_mmcif_host *host, uintptr_t slave_id)
 {
-        struct dma_slave_config cfg = { 0, };
-        struct dma_chan *chan;
-        void *slave_data = NULL;
-        struct resource *res;
-        struct device *dev = sh_mmcif_host_to_dev(host);
         dma_cap_mask_t mask;
-        int ret;
 
         dma_cap_zero(mask);
         dma_cap_set(DMA_SLAVE, mask);
+        if (slave_id <= 0)
+                return NULL;
 
-        if (pdata)
-                slave_data = direction == DMA_MEM_TO_DEV ?
-                        (void *)pdata->slave_id_tx :
-                        (void *)pdata->slave_id_rx;
-
-        chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
-                                slave_data, dev,
-                                direction == DMA_MEM_TO_DEV ? "tx" : "rx");
-
-        dev_dbg(dev, "%s: %s: got channel %p\n", __func__,
-                direction == DMA_MEM_TO_DEV ? "TX" : "RX", chan);
+        return dma_request_channel(mask, shdma_chan_filter, (void *)slave_id);
+}
 
-        if (!chan)
-                return NULL;
+static int sh_mmcif_dma_slave_config(struct sh_mmcif_host *host,
+                                     struct dma_chan *chan,
+                                     enum dma_transfer_direction direction)
+{
+        struct resource *res;
+        struct dma_slave_config cfg = { 0, };
 
         res = platform_get_resource(host->pd, IORESOURCE_MEM, 0);
-
         cfg.direction = direction;
 
         if (direction == DMA_DEV_TO_MEM) {
@@ -439,38 +427,42 @@ sh_mmcif_request_dma_one(struct sh_mmcif_host *host,
                 cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
         }
 
-        ret = dmaengine_slave_config(chan, &cfg);
-        if (ret < 0) {
-                dma_release_channel(chan);
-                return NULL;
-        }
-
-        return chan;
+        return dmaengine_slave_config(chan, &cfg);
 }
 
-static void sh_mmcif_request_dma(struct sh_mmcif_host *host,
-                                 struct sh_mmcif_plat_data *pdata)
+static void sh_mmcif_request_dma(struct sh_mmcif_host *host)
 {
         struct device *dev = sh_mmcif_host_to_dev(host);
         host->dma_active = false;
 
-        if (pdata) {
-                if (pdata->slave_id_tx <= 0 || pdata->slave_id_rx <= 0)
-                        return;
-        } else if (!dev->of_node) {
-                return;
+        /* We can only either use DMA for both Tx and Rx or not use it at all */
+        if (IS_ENABLED(CONFIG_SUPERH) && dev->platform_data) {
+                struct sh_mmcif_plat_data *pdata = dev->platform_data;
+
+                host->chan_tx = sh_mmcif_request_dma_pdata(host,
+                                                        pdata->slave_id_tx);
+                host->chan_rx = sh_mmcif_request_dma_pdata(host,
+                                                        pdata->slave_id_rx);
+        } else {
+                host->chan_tx = dma_request_slave_channel(dev, "tx");
+                host->chan_tx = dma_request_slave_channel(dev, "rx");
         }
+        dev_dbg(dev, "%s: got channel TX %p RX %p\n", __func__, host->chan_tx,
+                host->chan_rx);
 
-        /* We can only either use DMA for both Tx and Rx or not use it at all */
-        host->chan_tx = sh_mmcif_request_dma_one(host, pdata, DMA_MEM_TO_DEV);
-        if (!host->chan_tx)
-                return;
+        if (!host->chan_tx || !host->chan_rx ||
+            sh_mmcif_dma_slave_config(host, host->chan_tx, DMA_MEM_TO_DEV) ||
+            sh_mmcif_dma_slave_config(host, host->chan_rx, DMA_DEV_TO_MEM))
+                goto error;
 
-        host->chan_rx = sh_mmcif_request_dma_one(host, pdata, DMA_DEV_TO_MEM);
-        if (!host->chan_rx) {
+        return;
+
+error:
+        if (host->chan_tx)
                 dma_release_channel(host->chan_tx);
-                host->chan_tx = NULL;
-        }
+        if (host->chan_rx)
+                dma_release_channel(host->chan_rx);
+        host->chan_tx = host->chan_rx = NULL;
 }
 
 static void sh_mmcif_release_dma(struct sh_mmcif_host *host)
@@ -1102,7 +1094,7 @@ static void sh_mmcif_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
         if (ios->power_mode == MMC_POWER_UP) {
                 if (!host->card_present) {
                         /* See if we also get DMA */
-                        sh_mmcif_request_dma(host, dev->platform_data);
+                        sh_mmcif_request_dma(host);
                         host->card_present = true;
                 }
                 sh_mmcif_set_power(host, ios);