atmel-mci: convert to dma_request_channel and down-level dma_slave

dma_request_channel provides an exclusive channel, so we no longer need to
pass slave data through dmaengine.

Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

3 files changed, 33 insertions, 98 deletions

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 7a0594f24a3f..90aca505a1df 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -234,10 +234,6 @@ static void dma_client_chan_alloc(struct dma_client *client)
 	list_for_each_entry(device, &dma_device_list, global_node) {
 		if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
 			continue;
-		/* Does the client require a specific DMA controller? */
-		if (client->slave && client->slave->dma_dev
-				&& client->slave->dma_dev != device->dev)
-			continue;
 		if (!dma_device_satisfies_mask(device, client->cap_mask))
 			continue;
 
@@ -613,10 +609,6 @@ void dma_async_client_register(struct dma_client *client)
 	struct dma_chan *chan;
 	int err;
 
-	/* validate client data */
-	BUG_ON(dma_has_cap(DMA_SLAVE, client->cap_mask) &&
-		!client->slave);
-
 	mutex_lock(&dma_list_mutex);
 	dmaengine_ref_count++;
 
diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index 377dafa37a20..dbd50804e5d2 100644
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -567,7 +567,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 	if (unlikely(!dws || !sg_len))
 		return NULL;
 
-	reg_width = dws->slave.reg_width;
+	reg_width = dws->reg_width;
 	prev = first = NULL;
 
 	sg_len = dma_map_sg(chan->dev.parent, sgl, sg_len, direction);
@@ -579,7 +579,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 				| DWC_CTLL_DST_FIX
 				| DWC_CTLL_SRC_INC
 				| DWC_CTLL_FC_M2P);
-		reg = dws->slave.tx_reg;
+		reg = dws->tx_reg;
 		for_each_sg(sgl, sg, sg_len, i) {
 			struct dw_desc	*desc;
 			u32		len;
@@ -625,7 +625,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 				| DWC_CTLL_SRC_FIX
 				| DWC_CTLL_FC_P2M);
 
-		reg = dws->slave.rx_reg;
+		reg = dws->rx_reg;
 		for_each_sg(sgl, sg, sg_len, i) {
 			struct dw_desc	*desc;
 			u32		len;
@@ -764,7 +764,6 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan,
 	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
 	struct dw_dma		*dw = to_dw_dma(chan->device);
 	struct dw_desc		*desc;
-	struct dma_slave	*slave;
 	struct dw_dma_slave	*dws;
 	int			i;
 	u32			cfghi;
@@ -772,12 +771,6 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan,
 
 	dev_vdbg(&chan->dev, "alloc_chan_resources\n");
 
-	/* Channels doing slave DMA can only handle one client. */
-	if (dwc->dws || (client && client->slave)) {
-		if (chan->client_count)
-			return -EBUSY;
-	}
-
 	/* ASSERT:  channel is idle */
 	if (dma_readl(dw, CH_EN) & dwc->mask) {
 		dev_dbg(&chan->dev, "DMA channel not idle?\n");
@@ -789,23 +782,17 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan,
 	cfghi = DWC_CFGH_FIFO_MODE;
 	cfglo = 0;
 
-	slave = client->slave;
-	if (slave) {
+	dws = dwc->dws;
+	if (dws) {
 		/*
 		 * We need controller-specific data to set up slave
 		 * transfers.
 		 */
-		BUG_ON(!slave->dma_dev || slave->dma_dev != dw->dma.dev);
-
-		dws = container_of(slave, struct dw_dma_slave, slave);
+		BUG_ON(!dws->dma_dev || dws->dma_dev != dw->dma.dev);
 
-		dwc->dws = dws;
 		cfghi = dws->cfg_hi;
 		cfglo = dws->cfg_lo;
-	} else {
-		dwc->dws = NULL;
 	}
-
 	channel_writel(dwc, CFG_LO, cfglo);
 	channel_writel(dwc, CFG_HI, cfghi);
 
diff --git a/drivers/mmc/host/atmel-mci.c b/drivers/mmc/host/atmel-mci.c
index 6c11f4d4c4e9..7a34118507db 100644
--- a/drivers/mmc/host/atmel-mci.c
+++ b/drivers/mmc/host/atmel-mci.c
@@ -1441,60 +1441,6 @@ static irqreturn_t atmci_detect_interrupt(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-#ifdef CONFIG_MMC_ATMELMCI_DMA
-
-static inline struct atmel_mci *
-dma_client_to_atmel_mci(struct dma_client *client)
-{
-	return container_of(client, struct atmel_mci, dma.client);
-}
-
-static enum dma_state_client atmci_dma_event(struct dma_client *client,
-		struct dma_chan *chan, enum dma_state state)
-{
-	struct atmel_mci	*host;
-	enum dma_state_client	ret = DMA_NAK;
-
-	host = dma_client_to_atmel_mci(client);
-
-	switch (state) {
-	case DMA_RESOURCE_AVAILABLE:
-		spin_lock_bh(&host->lock);
-		if (!host->dma.chan) {
-			host->dma.chan = chan;
-			ret = DMA_ACK;
-		}
-		spin_unlock_bh(&host->lock);
-
-		if (ret == DMA_ACK)
-			dev_info(&host->pdev->dev,
-					"Using %s for DMA transfers\n",
-					chan->dev.bus_id);
-		break;
-
-	case DMA_RESOURCE_REMOVED:
-		spin_lock_bh(&host->lock);
-		if (host->dma.chan == chan) {
-			host->dma.chan = NULL;
-			ret = DMA_ACK;
-		}
-		spin_unlock_bh(&host->lock);
-
-		if (ret == DMA_ACK)
-			dev_info(&host->pdev->dev,
-					"Lost %s, falling back to PIO\n",
-					chan->dev.bus_id);
-		break;
-
-	default:
-		break;
-	}
-
-
-	return ret;
-}
-#endif /* CONFIG_MMC_ATMELMCI_DMA */
-
 static int __init atmci_init_slot(struct atmel_mci *host,
 		struct mci_slot_pdata *slot_data, unsigned int id,
 		u32 sdc_reg)
@@ -1598,6 +1544,18 @@ static void __exit atmci_cleanup_slot(struct atmel_mci_slot *slot,
 	mmc_free_host(slot->mmc);
 }
 
+#ifdef CONFIG_MMC_ATMELMCI_DMA
+static enum dma_state_client filter(struct dma_chan *chan, void *slave)
+{
+	struct dw_dma_slave *dws = slave;
+
+	if (dws->dma_dev == chan->device->dev)
+		return DMA_ACK;
+	else
+		return DMA_DUP;
+}
+#endif
+
 static int __init atmci_probe(struct platform_device *pdev)
 {
 	struct mci_platform_data	*pdata;
@@ -1650,22 +1608,20 @@ static int __init atmci_probe(struct platform_device *pdev)
 		goto err_request_irq;
 
 #ifdef CONFIG_MMC_ATMELMCI_DMA
-	if (pdata->dma_slave) {
-		struct dma_slave *slave = pdata->dma_slave;
+	if (pdata->dma_slave.dma_dev) {
+		struct dw_dma_slave *dws = &pdata->dma_slave;
+		dma_cap_mask_t mask;
 
-		slave->tx_reg = regs->start + MCI_TDR;
-		slave->rx_reg = regs->start + MCI_RDR;
+		dws->tx_reg = regs->start + MCI_TDR;
+		dws->rx_reg = regs->start + MCI_RDR;
 
 		/* Try to grab a DMA channel */
-		host->dma.client.event_callback = atmci_dma_event;
-		dma_cap_set(DMA_SLAVE, host->dma.client.cap_mask);
-		host->dma.client.slave = slave;
-
-		dma_async_client_register(&host->dma.client);
-		dma_async_client_chan_request(&host->dma.client);
-	} else {
-		dev_notice(&pdev->dev, "DMA not available, using PIO\n");
+		dma_cap_zero(mask);
+		dma_cap_set(DMA_SLAVE, mask);
+		host->dma.chan = dma_request_channel(mask, filter, dws);
 	}
+	if (!host->dma.chan)
+		dev_notice(&pdev->dev, "DMA not available, using PIO\n");
 #endif /* CONFIG_MMC_ATMELMCI_DMA */
 
 	platform_set_drvdata(pdev, host);
@@ -1697,8 +1653,8 @@ static int __init atmci_probe(struct platform_device *pdev)
 
 err_init_slot:
 #ifdef CONFIG_MMC_ATMELMCI_DMA
-	if (pdata->dma_slave)
-		dma_async_client_unregister(&host->dma.client);
+	if (host->dma.chan)
+		dma_release_channel(host->dma.chan);
 #endif
 	free_irq(irq, host);
 err_request_irq:
@@ -1729,8 +1685,8 @@ static int __exit atmci_remove(struct platform_device *pdev)
 	clk_disable(host->mck);
 
 #ifdef CONFIG_MMC_ATMELMCI_DMA
-	if (host->dma.client.slave)
-		dma_async_client_unregister(&host->dma.client);
+	if (host->dma.chan)
+		dma_release_channel(host->dma.chan);
 #endif
 
 	free_irq(platform_get_irq(pdev, 0), host);
@@ -1759,7 +1715,7 @@ static void __exit atmci_exit(void)
 	platform_driver_unregister(&atmci_driver);
 }
 
-module_init(atmci_init);
+late_initcall(atmci_init); /* try to load after dma driver when built-in */
 module_exit(atmci_exit);
 
 MODULE_DESCRIPTION("Atmel Multimedia Card Interface driver");