mmc: mmci: Add and implement a ->dma_setup() callback for qcom dml

As a first step to improve the variant specific code for mmci, add a
->dma_setup() callback to the struct mmci_host_ops.

To show its use, let's deploy the callback for the qcom dml, which involves
also to the assign the mmci_host_ops pointer from the variant ->init()
callback.

Signed-off-by: Ulf Hansson <[e-mail]>
Reviewed-by: Ludovic Barre <[e-mail]>

drivers/mmc/host/mmci.c

···
 	.mmcimask1		= true,
 	.start_err		= MCI_STARTBITERR,
 	.opendrain		= MCI_ROD,
+	.init			= qcom_variant_init,
 };
 
 /* Busy detection for the ST Micro variant */
···
 static void mmci_dma_setup(struct mmci_host *host)
 {
 	const char *rxname, *txname;
-	struct variant_data *variant = host->variant;
 
 	host->dma_rx_channel = dma_request_slave_channel(mmc_dev(host->mmc), "rx");
 	host->dma_tx_channel = dma_request_slave_channel(mmc_dev(host->mmc), "tx");
···
 			host->mmc->max_seg_size = max_seg_size;
 	}
 
-	if (variant->qcom_dml && host->dma_rx_channel && host->dma_tx_channel)
-		if (dml_hw_init(host, host->mmc->parent->of_node))
-			variant->qcom_dml = false;
+	if (host->ops && host->ops->dma_setup)
+		host->ops->dma_setup(host);
 }
 
 /*

drivers/mmc/host/mmci.h

···
 
 /* mmci variant callbacks */
 struct mmci_host_ops {
+	void (*dma_setup)(struct mmci_host *host);
 };
 
 struct mmci_host_next {

drivers/mmc/host/mmci_qcom_dml.c

···
 }
 
 /* Initialize the dml hardware connected to SD Card controller */
-int dml_hw_init(struct mmci_host *host, struct device_node *np)
+static void qcom_dma_setup(struct mmci_host *host)
 {
 	u32 config;
 	void __iomem *base;
 	int consumer_id, producer_id;
+	struct device_node *np = host->mmc->parent->of_node;
 
 	consumer_id = of_get_dml_pipe_index(np, "tx");
 	producer_id = of_get_dml_pipe_index(np, "rx");
 
-	if (producer_id < 0 || consumer_id < 0)
-		return -ENODEV;
+	if (producer_id < 0 || consumer_id < 0) {
+		host->variant->qcom_dml = false;
+		return;
+	}
 
 	base = host->base + DML_OFFSET;
 
···
 
 	/* Make sure dml initialization is finished */
 	mb();
+}
 
-	return 0;
+static struct mmci_host_ops qcom_variant_ops = {
+	.dma_setup = qcom_dma_setup,
+};
+
+void qcom_variant_init(struct mmci_host *host)
+{
+	host->ops = &qcom_variant_ops;
 }

drivers/mmc/host/mmci_qcom_dml.h

···
 #define __MMC_QCOM_DML_H__
 
 #ifdef CONFIG_MMC_QCOM_DML
-int dml_hw_init(struct mmci_host *host, struct device_node *np);
+void qcom_variant_init(struct mmci_host *host);
 void dml_start_xfer(struct mmci_host *host, struct mmc_data *data);
 #else
-static inline int dml_hw_init(struct mmci_host *host, struct device_node *np)
+static inline void qcom_variant_init(struct mmci_host *host)
 {
-	return -ENOSYS;
 }
 static inline void dml_start_xfer(struct mmci_host *host, struct mmc_data *data)
 {