spi: pic32: Retire dma_request_slave_channel_compat()

There is no reason to use the dma_request_slave_channel_compat() as no
filter function and parameter is provided.

Switch the driver to use dma_request_chan() instead and add support for
deferred probing against DMA channel.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20191121092703.30465-1-peter.ujfalusi@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-pic32.c

@@ -606,25 +606,30 @@ static void pic32_spi_cleanup(struct spi_device *spi)
 	gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
 }
 
-static void pic32_spi_dma_prep(struct pic32_spi *pic32s, struct device *dev)
+static int pic32_spi_dma_prep(struct pic32_spi *pic32s, struct device *dev)
 {
 	struct spi_master *master = pic32s->master;
-	dma_cap_mask_t mask;
+	int ret = 0;
 
-	dma_cap_zero(mask);
-	dma_cap_set(DMA_SLAVE, mask);
+	master->dma_rx = dma_request_chan(dev, "spi-rx");
+	if (IS_ERR(master->dma_rx)) {
+		if (PTR_ERR(master->dma_rx) == -EPROBE_DEFER)
+			ret = -EPROBE_DEFER;
+		else
+			dev_warn(dev, "RX channel not found.\n");
 
-	master->dma_rx = dma_request_slave_channel_compat(mask, NULL, NULL,
-							  dev, "spi-rx");
-	if (!master->dma_rx) {
-		dev_warn(dev, "RX channel not found.\n");
+		master->dma_rx = NULL;
 		goto out_err;
 	}
 
-	master->dma_tx = dma_request_slave_channel_compat(mask, NULL, NULL,
-							  dev, "spi-tx");
-	if (!master->dma_tx) {
-		dev_warn(dev, "TX channel not found.\n");
+	master->dma_tx = dma_request_chan(dev, "spi-tx");
+	if (IS_ERR(master->dma_tx)) {
+		if (PTR_ERR(master->dma_tx) == -EPROBE_DEFER)
+			ret = -EPROBE_DEFER;
+		else
+			dev_warn(dev, "TX channel not found.\n");
+
+		master->dma_tx = NULL;
 		goto out_err;
 	}
 
@@ -634,14 +639,20 @@ static void pic32_spi_dma_prep(struct pic32_spi *pic32s, struct device *dev)
 	/* DMA chnls allocated and prepared */
 	set_bit(PIC32F_DMA_PREP, &pic32s->flags);
 
-	return;
+	return 0;
 
 out_err:
-	if (master->dma_rx)
+	if (master->dma_rx) {
 		dma_release_channel(master->dma_rx);
+		master->dma_rx = NULL;
+	}
 
-	if (master->dma_tx)
+	if (master->dma_tx) {
 		dma_release_channel(master->dma_tx);
+		master->dma_tx = NULL;
+	}
+
+	return ret;
 }
 
 static void pic32_spi_dma_unprep(struct pic32_spi *pic32s)
@@ -776,7 +787,10 @@ static int pic32_spi_probe(struct platform_device *pdev)
 	master->unprepare_transfer_hardware	= pic32_spi_unprepare_hardware;
 
 	/* optional DMA support */
-	pic32_spi_dma_prep(pic32s, &pdev->dev);
+	ret = pic32_spi_dma_prep(pic32s, &pdev->dev);
+	if (ret)
+		goto err_bailout;
+
 	if (test_bit(PIC32F_DMA_PREP, &pic32s->flags))
 		master->can_dma	= pic32_spi_can_dma;