dmaengine: shdma: prepare to stop using struct dma_chan::private

Using struct dma_chan::private is deprecated. To update the shdma driver to
stop using it we first have to eliminate internal runtime uses of it. After
that we will also be able to stop using it for channel configuration.

Signed-off-by: Guennadi Liakhovetski <[e-mail]>
Signed-off-by: Vinod Koul <[e-mail]>

drivers/dma/sh/shdma-base.c

···
 		container_of(tx, struct shdma_desc, async_tx),
 		*last = desc;
 	struct shdma_chan *schan = to_shdma_chan(tx->chan);
-	struct shdma_slave *slave = tx->chan->private;
+	struct shdma_slave *slave = schan->slave;
 	dma_async_tx_callback callback = tx->callback;
 	dma_cookie_t cookie;
 	bool power_up;
···
 		goto edescalloc;
 	}
 	schan->desc_num = NR_DESCS_PER_CHANNEL;
+	schan->slave = slave;
 
 	for (i = 0; i < NR_DESCS_PER_CHANNEL; i++) {
 		desc = ops->embedded_desc(schan->desc, i);
···
 	if (!list_empty(&schan->ld_queue))
 		shdma_chan_ld_cleanup(schan, true);
 
-	if (chan->private) {
+	if (schan->slave) {
 		/* The caller is holding dma_list_mutex */
-		struct shdma_slave *slave = chan->private;
+		struct shdma_slave *slave = schan->slave;
 		clear_bit(slave->slave_id, shdma_slave_used);
 		chan->private = NULL;
 	}
···
 	struct shdma_chan *schan = to_shdma_chan(chan);
 	struct shdma_dev *sdev = to_shdma_dev(schan->dma_chan.device);
 	const struct shdma_ops *ops = sdev->ops;
-	struct shdma_slave *slave = chan->private;
+	struct shdma_slave *slave = schan->slave;
 	dma_addr_t slave_addr;
 
 	if (!chan)

drivers/dma/sh/shdma.c

···
 						    shdma_chan);
 
 	if (sslave) {
-		struct sh_dmae_slave *slave = container_of(sslave,
-					struct sh_dmae_slave, shdma_slave);
 		const struct sh_dmae_slave_config *cfg =
-			slave->config;
+			sh_chan->config;
 
 		dmae_set_dmars(sh_chan, cfg->mid_rid);
 		dmae_set_chcr(sh_chan, cfg->chcr);
···
 {
 	struct sh_dmae_chan *sh_chan = container_of(schan, struct sh_dmae_chan,
 						    shdma_chan);
-	struct sh_dmae_slave *slave = container_of(sslave, struct sh_dmae_slave,
-						   shdma_slave);
 	const struct sh_dmae_slave_config *cfg = dmae_find_slave(sh_chan, sslave->slave_id);
 	if (!cfg)
 		return -ENODEV;
 
-	slave->config = cfg;
+	sh_chan->config = cfg;
 
 	return 0;
 }
···
 
 	for (i = 0; i < shdev->pdata->channel_num; i++) {
 		struct sh_dmae_chan *sh_chan = shdev->chan[i];
-		struct sh_dmae_slave *param = sh_chan->shdma_chan.dma_chan.private;
 
 		if (!sh_chan->shdma_chan.desc_num)
 			continue;
 
-		if (param) {
-			const struct sh_dmae_slave_config *cfg = param->config;
+		if (sh_chan->shdma_chan.slave) {
+			const struct sh_dmae_slave_config *cfg = sh_chan->config;
 			dmae_set_dmars(sh_chan, cfg->mid_rid);
 			dmae_set_chcr(sh_chan, cfg->chcr);
 		} else {
···
 
 static dma_addr_t sh_dmae_slave_addr(struct shdma_chan *schan)
 {
-	struct sh_dmae_slave *param = schan->dma_chan.private;
+	struct sh_dmae_chan *sh_chan = container_of(schan,
+					struct sh_dmae_chan, shdma_chan);
 
 	/*
-	 * Implicit BUG_ON(!param)
-	 * if (param != NULL), this is a successfully requested slave channel,
-	 * therefore param->config != NULL too.
+	 * Implicit BUG_ON(!sh_chan->config)
+	 * This is an exclusive slave DMA operation, may only be called after a
+	 * successful slave configuration.
 	 */
-	return param->config->addr;
+	return sh_chan->config->addr;
 }
 
 static struct shdma_desc *sh_dmae_embedded_desc(void *buf, int i)

drivers/dma/sh/shdma.h

···
 #ifndef __DMA_SHDMA_H
 #define __DMA_SHDMA_H
 
+#include <linux/sh_dma.h>
 #include <linux/shdma-base.h>
 #include <linux/dmaengine.h>
 #include <linux/interrupt.h>
···
 
 struct sh_dmae_chan {
 	struct shdma_chan shdma_chan;
+	const struct sh_dmae_slave_config *config; /* Slave DMA configuration */
 	int xmit_shift;			/* log_2(bytes_per_xfer) */
 	u32 __iomem *base;
 	char dev_id[16];		/* unique name per DMAC of channel */

include/linux/sh_dma.h

···
 /* Used by slave DMA clients to request DMA to/from a specific peripheral */
 struct sh_dmae_slave {
 	struct shdma_slave		shdma_slave;	/* Set by the platform */
-	struct device			*dma_dev;	/* Set by the platform */
-	const struct sh_dmae_slave_config *config;	/* Set by the driver */
 };
 
 /*

include/linux/shdma-base.h

···
 	size_t max_xfer_len;		/* max transfer length */
 	int id;				/* Raw id of this channel */
 	int irq;			/* Channel IRQ */
+	struct shdma_slave *slave;	/* Client data for slave DMA */
 	enum shdma_pm_state pm_state;
 };