dmaengine: PL08x: Add support for different offset of CONFIG register

Some variants of PL08x (namely PL080S, found in Samsung S3C64xx SoCs)
have CONFIG register at different offset. This patch makes the driver
use offset from vendor data struct.
Signed-off-by: Tomasz Figa <tomasz.figa@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/amba-pl08x.c

@@ -102,6 +102,7 @@ struct pl08x_driver_data;
  *	missing
  */
 struct vendor_data {
+	u8 config_offset;
 	u8 channels;
 	bool dualmaster;
 	bool nomadik;
@@ -145,6 +146,7 @@ struct pl08x_bus_data {
 struct pl08x_phy_chan {
 	unsigned int id;
 	void __iomem *base;
+	void __iomem *reg_config;
 	spinlock_t lock;
 	struct pl08x_dma_chan *serving;
 	bool locked;
@@ -334,7 +336,7 @@ static int pl08x_phy_channel_busy(struct pl08x_phy_chan *ch)
 {
 	unsigned int val;
 
-	val = readl(ch->base + PL080_CH_CONFIG);
+	val = readl(ch->reg_config);
 	return val & PL080_CONFIG_ACTIVE;
 }
 
@@ -373,7 +375,7 @@ static void pl08x_start_next_txd(struct pl08x_dma_chan *plchan)
 	writel(lli->dst, phychan->base + PL080_CH_DST_ADDR);
 	writel(lli->lli, phychan->base + PL080_CH_LLI);
 	writel(lli->cctl, phychan->base + PL080_CH_CONTROL);
-	writel(txd->ccfg, phychan->base + PL080_CH_CONFIG);
+	writel(txd->ccfg, phychan->reg_config);
 
 	/* Enable the DMA channel */
 	/* Do not access config register until channel shows as disabled */
@@ -381,11 +383,11 @@ static void pl08x_start_next_txd(struct pl08x_dma_chan *plchan)
 		cpu_relax();
 
 	/* Do not access config register until channel shows as inactive */
-	val = readl(phychan->base + PL080_CH_CONFIG);
+	val = readl(phychan->reg_config);
 	while ((val & PL080_CONFIG_ACTIVE) || (val & PL080_CONFIG_ENABLE))
-		val = readl(phychan->base + PL080_CH_CONFIG);
+		val = readl(phychan->reg_config);
 
-	writel(val | PL080_CONFIG_ENABLE, phychan->base + PL080_CH_CONFIG);
+	writel(val | PL080_CONFIG_ENABLE, phychan->reg_config);
 }
 
 /*
@@ -404,9 +406,9 @@ static void pl08x_pause_phy_chan(struct pl08x_phy_chan *ch)
 	int timeout;
 
 	/* Set the HALT bit and wait for the FIFO to drain */
-	val = readl(ch->base + PL080_CH_CONFIG);
+	val = readl(ch->reg_config);
 	val |= PL080_CONFIG_HALT;
-	writel(val, ch->base + PL080_CH_CONFIG);
+	writel(val, ch->reg_config);
 
 	/* Wait for channel inactive */
 	for (timeout = 1000; timeout; timeout--) {
@@ -423,9 +425,9 @@ static void pl08x_resume_phy_chan(struct pl08x_phy_chan *ch)
 	u32 val;
 
 	/* Clear the HALT bit */
-	val = readl(ch->base + PL080_CH_CONFIG);
+	val = readl(ch->reg_config);
 	val &= ~PL080_CONFIG_HALT;
-	writel(val, ch->base + PL080_CH_CONFIG);
+	writel(val, ch->reg_config);
 }
 
 /*
@@ -437,12 +439,12 @@ static void pl08x_resume_phy_chan(struct pl08x_phy_chan *ch)
 static void pl08x_terminate_phy_chan(struct pl08x_driver_data *pl08x,
 	struct pl08x_phy_chan *ch)
 {
-	u32 val = readl(ch->base + PL080_CH_CONFIG);
+	u32 val = readl(ch->reg_config);
 
 	val &= ~(PL080_CONFIG_ENABLE | PL080_CONFIG_ERR_IRQ_MASK |
 	         PL080_CONFIG_TC_IRQ_MASK);
 
-	writel(val, ch->base + PL080_CH_CONFIG);
+	writel(val, ch->reg_config);
 
 	writel(1 << ch->id, pl08x->base + PL080_ERR_CLEAR);
 	writel(1 << ch->id, pl08x->base + PL080_TC_CLEAR);
@@ -1952,6 +1954,7 @@ static int pl08x_probe(struct amba_device *adev, const struct amba_id *id)
 
 		ch->id = i;
 		ch->base = pl08x->base + PL080_Cx_BASE(i);
+		ch->reg_config = ch->base + vd->config_offset;
 		spin_lock_init(&ch->lock);
 
 		/*
@@ -1962,7 +1965,7 @@ static int pl08x_probe(struct amba_device *adev, const struct amba_id *id)
 		if (vd->nomadik) {
 			u32 val;
 
-			val = readl(ch->base + PL080_CH_CONFIG);
+			val = readl(ch->reg_config);
 			if (val & (PL080N_CONFIG_ITPROT | PL080N_CONFIG_SECPROT)) {
 				dev_info(&adev->dev, "physical channel %d reserved for secure access only\n", i);
 				ch->locked = true;
@@ -2043,17 +2046,20 @@ static int pl08x_probe(struct amba_device *adev, const struct amba_id *id)
 
 /* PL080 has 8 channels and the PL080 have just 2 */
 static struct vendor_data vendor_pl080 = {
+	.config_offset = PL080_CH_CONFIG,
 	.channels = 8,
 	.dualmaster = true,
 };
 
 static struct vendor_data vendor_nomadik = {
+	.config_offset = PL080_CH_CONFIG,
 	.channels = 8,
 	.dualmaster = true,
 	.nomadik = true,
 };
 
 static struct vendor_data vendor_pl081 = {
+	.config_offset = PL080_CH_CONFIG,
 	.channels = 2,
 	.dualmaster = false,
 };