DMAENGINE: add runtime slave control to COH 901 318 v3

This extends the DMA engine driver for the COH 901 318 used in the
U300 platform with the generic runtime slave control command.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/dma/coh901318.c

@@ -72,6 +72,9 @@ struct coh901318_chan {
 	unsigned long nbr_active_done;
 	unsigned long busy;
 
+	u32 runtime_addr;
+	u32 runtime_ctrl;
+
 	struct coh901318_base *base;
 };
 
@@ -190,6 +193,9 @@ static inline struct coh901318_chan *to_coh901318_chan(struct dma_chan *chan)
 static inline dma_addr_t
 cohc_dev_addr(struct coh901318_chan *cohc)
 {
+	/* Runtime supplied address will take precedence */
+	if (cohc->runtime_addr)
+		return cohc->runtime_addr;
 	return cohc->base->platform->chan_conf[cohc->id].dev_addr;
 }
 
@@ -1055,6 +1061,14 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 
 	params = cohc_chan_param(cohc);
 	config = params->config;
+	/*
+	 * Add runtime-specific control on top, make
+	 * sure the bits you set per peripheral channel are
+	 * cleared in the default config from the platform.
+	 */
+	ctrl_chained |= cohc->runtime_ctrl;
+	ctrl_last |= cohc->runtime_ctrl;
+	ctrl |= cohc->runtime_ctrl;
 
 	if (direction == DMA_TO_DEVICE) {
 		u32 tx_flags = COH901318_CX_CTRL_PRDD_SOURCE |
@@ -1113,6 +1127,12 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 	if (ret)
 		goto err_lli_fill;
 
+	/*
+	 * Set the default ctrl for the channel to the one from the lli,
+	 * things may have changed due to odd buffer alignment etc.
+	 */
+	coh901318_set_ctrl(cohc, lli->control);
+
 	COH_DBG(coh901318_list_print(cohc, lli));
 
 	/* Pick a descriptor to handle this transfer */
@@ -1175,6 +1195,146 @@ coh901318_issue_pending(struct dma_chan *chan)
 	spin_unlock_irqrestore(&cohc->lock, flags);
 }
 
+/*
+ * Here we wrap in the runtime dma control interface
+ */
+struct burst_table {
+	int burst_8bit;
+	int burst_16bit;
+	int burst_32bit;
+	u32 reg;
+};
+
+static const struct burst_table burst_sizes[] = {
+	{
+		.burst_8bit = 64,
+		.burst_16bit = 32,
+		.burst_32bit = 16,
+		.reg = COH901318_CX_CTRL_BURST_COUNT_64_BYTES,
+	},
+	{
+		.burst_8bit = 48,
+		.burst_16bit = 24,
+		.burst_32bit = 12,
+		.reg = COH901318_CX_CTRL_BURST_COUNT_48_BYTES,
+	},
+	{
+		.burst_8bit = 32,
+		.burst_16bit = 16,
+		.burst_32bit = 8,
+		.reg = COH901318_CX_CTRL_BURST_COUNT_32_BYTES,
+	},
+	{
+		.burst_8bit = 16,
+		.burst_16bit = 8,
+		.burst_32bit = 4,
+		.reg = COH901318_CX_CTRL_BURST_COUNT_16_BYTES,
+	},
+	{
+		.burst_8bit = 8,
+		.burst_16bit = 4,
+		.burst_32bit = 2,
+		.reg = COH901318_CX_CTRL_BURST_COUNT_8_BYTES,
+	},
+	{
+		.burst_8bit = 4,
+		.burst_16bit = 2,
+		.burst_32bit = 1,
+		.reg = COH901318_CX_CTRL_BURST_COUNT_4_BYTES,
+	},
+	{
+		.burst_8bit = 2,
+		.burst_16bit = 1,
+		.burst_32bit = 0,
+		.reg = COH901318_CX_CTRL_BURST_COUNT_2_BYTES,
+	},
+	{
+		.burst_8bit = 1,
+		.burst_16bit = 0,
+		.burst_32bit = 0,
+		.reg = COH901318_CX_CTRL_BURST_COUNT_1_BYTE,
+	},
+};
+
+static void coh901318_dma_set_runtimeconfig(struct dma_chan *chan,
+			struct dma_slave_config *config)
+{
+	struct coh901318_chan *cohc = to_coh901318_chan(chan);
+	dma_addr_t addr;
+	enum dma_slave_buswidth addr_width;
+	u32 maxburst;
+	u32 runtime_ctrl = 0;
+	int i = 0;
+
+	/* We only support mem to per or per to mem transfers */
+	if (config->direction == DMA_FROM_DEVICE) {
+		addr = config->src_addr;
+		addr_width = config->src_addr_width;
+		maxburst = config->src_maxburst;
+	} else if (config->direction == DMA_TO_DEVICE) {
+		addr = config->dst_addr;
+		addr_width = config->dst_addr_width;
+		maxburst = config->dst_maxburst;
+	} else {
+		dev_err(COHC_2_DEV(cohc), "illegal channel mode\n");
+		return;
+	}
+
+	dev_dbg(COHC_2_DEV(cohc), "configure channel for %d byte transfers\n",
+		addr_width);
+	switch (addr_width)  {
+	case DMA_SLAVE_BUSWIDTH_1_BYTE:
+		runtime_ctrl |=
+			COH901318_CX_CTRL_SRC_BUS_SIZE_8_BITS |
+			COH901318_CX_CTRL_DST_BUS_SIZE_8_BITS;
+
+		while (i < ARRAY_SIZE(burst_sizes)) {
+			if (burst_sizes[i].burst_8bit <= maxburst)
+				break;
+			i++;
+		}
+
+		break;
+	case DMA_SLAVE_BUSWIDTH_2_BYTES:
+		runtime_ctrl |=
+			COH901318_CX_CTRL_SRC_BUS_SIZE_16_BITS |
+			COH901318_CX_CTRL_DST_BUS_SIZE_16_BITS;
+
+		while (i < ARRAY_SIZE(burst_sizes)) {
+			if (burst_sizes[i].burst_16bit <= maxburst)
+				break;
+			i++;
+		}
+
+		break;
+	case DMA_SLAVE_BUSWIDTH_4_BYTES:
+		/* Direction doesn't matter here, it's 32/32 bits */
+		runtime_ctrl |=
+			COH901318_CX_CTRL_SRC_BUS_SIZE_32_BITS |
+			COH901318_CX_CTRL_DST_BUS_SIZE_32_BITS;
+
+		while (i < ARRAY_SIZE(burst_sizes)) {
+			if (burst_sizes[i].burst_32bit <= maxburst)
+				break;
+			i++;
+		}
+
+		break;
+	default:
+		dev_err(COHC_2_DEV(cohc),
+			"bad runtimeconfig: alien address width\n");
+		return;
+	}
+
+	runtime_ctrl |= burst_sizes[i].reg;
+	dev_dbg(COHC_2_DEV(cohc),
+		"selected burst size %d bytes for address width %d bytes, maxburst %d\n",
+		burst_sizes[i].burst_8bit, addr_width, maxburst);
+
+	cohc->runtime_addr = addr;
+	cohc->runtime_ctrl = runtime_ctrl;
+}
+
 static int
 coh901318_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 		  unsigned long arg)
@@ -1184,6 +1344,14 @@ coh901318_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 	struct coh901318_desc *cohd;
 	void __iomem *virtbase = cohc->base->virtbase;
 
+	if (cmd == DMA_SLAVE_CONFIG) {
+		struct dma_slave_config *config =
+			(struct dma_slave_config *) arg;
+
+		coh901318_dma_set_runtimeconfig(chan, config);
+		return 0;
+	  }
+
 	if (cmd == DMA_PAUSE) {
 		coh901318_pause(chan);
 		return 0;
@@ -1240,6 +1408,7 @@ coh901318_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 
 	return 0;
 }
+
 void coh901318_base_init(struct dma_device *dma, const int *pick_chans,
 			 struct coh901318_base *base)
 {