mmc: mmci: Re-work code starting DMA for the qcom variant

Having mmci_dmae_start() to invoke the shared function, dml_start_xfer(),
explicitly for the qcom variant isn't very nice. Let's clean up this code
by moving the qcom specific parts into the qcom ->dma_start() callback and
then drop dml_start_xfer() altogether.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

drivers/mmc/host/mmci.c

@@ -886,15 +886,11 @@ int mmci_dmae_prep_data(struct mmci_host *host,
 int mmci_dmae_start(struct mmci_host *host, unsigned int *datactrl)
 {
 	struct mmci_dmae_priv *dmae = host->dma_priv;
-	struct mmc_data *data = host->data;
 
 	host->dma_in_progress = true;
 	dmaengine_submit(dmae->desc_current);
 	dma_async_issue_pending(dmae->cur);
 
-	if (host->variant->qcom_dml)
-		dml_start_xfer(host, data);
-
 	*datactrl |= MCI_DPSM_DMAENABLE;
 
 	return 0;

drivers/mmc/host/mmci_qcom_dml.c

@@ -54,10 +54,15 @@
 
 #define DML_OFFSET			0x800
 
-void dml_start_xfer(struct mmci_host *host, struct mmc_data *data)
+static int qcom_dma_start(struct mmci_host *host, unsigned int *datactrl)
 {
 	u32 config;
 	void __iomem *base = host->base + DML_OFFSET;
+	struct mmc_data *data = host->data;
+	int ret = mmci_dmae_start(host, datactrl);
+
+	if (ret)
+		return ret;
 
 	if (data->flags & MMC_DATA_READ) {
 		/* Read operation: configure DML for producer operation */
@@ -96,6 +101,7 @@ void dml_start_xfer(struct mmci_host *host, struct mmc_data *data)
 
 	/* make sure the dml is configured before dma is triggered */
 	wmb();
+	return 0;
 }
 
 static int of_get_dml_pipe_index(struct device_node *np, const char *name)
@@ -188,7 +194,7 @@ static struct mmci_host_ops qcom_variant_ops = {
 	.get_next_data = mmci_dmae_get_next_data,
 	.dma_setup = qcom_dma_setup,
 	.dma_release = mmci_dmae_release,
-	.dma_start = mmci_dmae_start,
+	.dma_start = qcom_dma_start,
 	.dma_finalize = mmci_dmae_finalize,
 	.dma_error = mmci_dmae_error,
 };

drivers/mmc/host/mmci_qcom_dml.h

@@ -17,14 +17,10 @@
 
 #ifdef CONFIG_MMC_QCOM_DML
 void qcom_variant_init(struct mmci_host *host);
-void dml_start_xfer(struct mmci_host *host, struct mmc_data *data);
 #else
 static inline void qcom_variant_init(struct mmci_host *host)
 {
 }
-static inline void dml_start_xfer(struct mmci_host *host, struct mmc_data *data)
-{
-}
 #endif /* CONFIG_MMC_QCOM_DML */
 
 #endif /* __MMC_QCOM_DML_H__ */