diff mbox

[RFC,03/11] dma: amba-pl08x: Add support for different offset of CONFIG register

Message ID 1371416058-22047-4-git-send-email-tomasz.figa@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Tomasz Figa June 16, 2013, 8:54 p.m. UTC 
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>
---
 drivers/dma/amba-pl08x.c | 51 ++++++++++++++++++++++++++++--------------------
 1 file changed, 30 insertions(+), 21 deletions(-)

Comments

Russell King - ARM Linux June 17, 2013, 6:52 p.m. UTC | #1 
On Sun, Jun 16, 2013 at 10:54:10PM +0200, Tomasz Figa wrote:
> 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.

I'd suggest doing this a different way.  Instead of having to pass around
two pointers everywhere in order to access this register, add to
struct pl08x_phy_chan a void __iomem *reg_config; member, and initialize
that to base + vd->config_offset.  Then use ch->reg_cfg instead of
ch->base + PL080_CH_CONFIG.

This has the benefit that you won't have to modify a whole load of
functions to pass another argument, which costs not only an additional
register, but also storage to keep it around.
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Tomasz Figa June 17, 2013, 7:02 p.m. UTC | #2 
On Monday 17 of June 2013 19:52:23 Russell King - ARM Linux wrote:
> On Sun, Jun 16, 2013 at 10:54:10PM +0200, Tomasz Figa wrote:
> > 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.
> 
> I'd suggest doing this a different way.  Instead of having to pass
> around two pointers everywhere in order to access this register, add to
> struct pl08x_phy_chan a void __iomem *reg_config; member, and
> initialize that to base + vd->config_offset.  Then use ch->reg_cfg
> instead of ch->base + PL080_CH_CONFIG.
> 
> This has the benefit that you won't have to modify a whole load of
> functions to pass another argument, which costs not only an additional
> register, but also storage to keep it around.

OK. Let me do it this way and see how it turns out. However keep in mind 
that next patch adds further dependencies on access to vendor_data struct, 
so there is nothing sure.

Best regards,
Tomasz

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diff mbox

Patch

diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index 1e57ded..93913b4 100644
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -107,6 +107,7 @@  struct pl08x_driver_data;
  * @flags: Vendor-specific flags, see PL08X_IS_*
  */
 struct vendor_data {
+	u8 config_offset;
 	u8 channels;
 	u32 flags;
 };
@@ -334,11 +335,12 @@  static void pl08x_release_mux(struct pl08x_dma_chan *plchan)
  */
 
 /* Whether a certain channel is busy or not */
-static int pl08x_phy_channel_busy(struct pl08x_phy_chan *ch)
+static int pl08x_phy_channel_busy(struct pl08x_driver_data *pl08x,
+						struct pl08x_phy_chan *ch)
 {
 	unsigned int val;
 
-	val = readl(ch->base + PL080_CH_CONFIG);
+	val = readl(ch->base + pl08x->vd->config_offset);
 	return val & PL080_CONFIG_ACTIVE;
 }
 
@@ -362,7 +364,7 @@  static void pl08x_start_next_txd(struct pl08x_dma_chan *plchan)
 	plchan->at = txd;
 
 	/* Wait for channel inactive */
-	while (pl08x_phy_channel_busy(phychan))
+	while (pl08x_phy_channel_busy(pl08x, phychan))
 		cpu_relax();
 
 	lli = &txd->llis_va[0];
@@ -377,7 +379,7 @@  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->base + pl08x->vd->config_offset);
 
 	/* Enable the DMA channel */
 	/* Do not access config register until channel shows as disabled */
@@ -385,11 +387,13 @@  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->base + pl08x->vd->config_offset);
 	while ((val & PL080_CONFIG_ACTIVE) || (val & PL080_CONFIG_ENABLE))
-		val = readl(phychan->base + PL080_CH_CONFIG);
+		val = readl(phychan->base + pl08x->vd->config_offset);
 
-	writel(val | PL080_CONFIG_ENABLE, phychan->base + PL080_CH_CONFIG);
+	writel(val | PL080_CONFIG_ENABLE,
+				phychan->base + pl08x->vd->config_offset);
 }
 
 /*
@@ -402,34 +406,36 @@  static void pl08x_start_next_txd(struct pl08x_dma_chan *plchan)
  * For P->M transfers, disable the peripheral first to stop it filling
  * the DMAC FIFO, and then pause the DMAC.
  */
-static void pl08x_pause_phy_chan(struct pl08x_phy_chan *ch)
+static void pl08x_pause_phy_chan(struct pl08x_driver_data *pl08x,
+						struct pl08x_phy_chan *ch)
 {
 	u32 val;
 	int timeout;
 
 	/* Set the HALT bit and wait for the FIFO to drain */
-	val = readl(ch->base + PL080_CH_CONFIG);
+	val = readl(ch->base + pl08x->vd->config_offset);
 	val |= PL080_CONFIG_HALT;
-	writel(val, ch->base + PL080_CH_CONFIG);
+	writel(val, ch->base + pl08x->vd->config_offset);
 
 	/* Wait for channel inactive */
 	for (timeout = 1000; timeout; timeout--) {
-		if (!pl08x_phy_channel_busy(ch))
+		if (!pl08x_phy_channel_busy(pl08x, ch))
 			break;
 		udelay(1);
 	}
-	if (pl08x_phy_channel_busy(ch))
+	if (pl08x_phy_channel_busy(pl08x, ch))
 		pr_err("pl08x: channel%u timeout waiting for pause\n", ch->id);
 }
 
-static void pl08x_resume_phy_chan(struct pl08x_phy_chan *ch)
+static void pl08x_resume_phy_chan(struct pl08x_driver_data *pl08x,
+						struct pl08x_phy_chan *ch)
 {
 	u32 val;
 
 	/* Clear the HALT bit */
-	val = readl(ch->base + PL080_CH_CONFIG);
+	val = readl(ch->base + pl08x->vd->config_offset);
 	val &= ~PL080_CONFIG_HALT;
-	writel(val, ch->base + PL080_CH_CONFIG);
+	writel(val, ch->base + pl08x->vd->config_offset);
 }
 
 /*
@@ -441,12 +447,12 @@  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->base + pl08x->vd->config_offset);
 
 	val &= ~(PL080_CONFIG_ENABLE | PL080_CONFIG_ERR_IRQ_MASK |
 	         PL080_CONFIG_TC_IRQ_MASK);
 
-	writel(val, ch->base + PL080_CH_CONFIG);
+	writel(val, ch->base + pl08x->vd->config_offset);
 
 	writel(1 << ch->id, pl08x->base + PL080_ERR_CLEAR);
 	writel(1 << ch->id, pl08x->base + PL080_TC_CLEAR);
@@ -1576,11 +1582,11 @@  static int pl08x_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
 		pl08x_free_txd_list(pl08x, plchan);
 		break;
 	case DMA_PAUSE:
-		pl08x_pause_phy_chan(plchan->phychan);
+		pl08x_pause_phy_chan(pl08x, plchan->phychan);
 		plchan->state = PL08X_CHAN_PAUSED;
 		break;
 	case DMA_RESUME:
-		pl08x_resume_phy_chan(plchan->phychan);
+		pl08x_resume_phy_chan(pl08x, plchan->phychan);
 		plchan->state = PL08X_CHAN_RUNNING;
 		break;
 	default:
@@ -1966,7 +1972,7 @@  static int pl08x_probe(struct amba_device *adev, const struct amba_id *id)
 		if (vd->flags & PL08X_IS_NOMADIK) {
 			u32 val;
 
-			val = readl(ch->base + PL080_CH_CONFIG);
+			val = readl(ch->base + vd->config_offset);
 			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;
@@ -1974,7 +1980,7 @@  static int pl08x_probe(struct amba_device *adev, const struct amba_id *id)
 		}
 
 		dev_dbg(&adev->dev, "physical channel %d is %s\n",
-			i, pl08x_phy_channel_busy(ch) ? "BUSY" : "FREE");
+			i, pl08x_phy_channel_busy(pl08x, ch) ? "BUSY" : "FREE");
 	}
 
 	/* Register as many memcpy channels as there are physical channels */
@@ -2049,16 +2055,19 @@  out_no_pl08x:
 static struct vendor_data vendor_pl080 = {
 	.channels = 8,
 	.flags = PL08X_IS_DUALMASTER,
+	.config_offset = PL080_CH_CONFIG,
 };
 
 static struct vendor_data vendor_nomadik = {
 	.channels = 8,
 	.flags = PL08X_IS_DUALMASTER | PL08X_IS_NOMADIK,
+	.config_offset = PL080_CH_CONFIG,
 };
 
 static struct vendor_data vendor_pl081 = {
 	.channels = 2,
 	.flags = 0,
+	.config_offset = PL080_CH_CONFIG,
 };
 
 static struct amba_id pl08x_ids[] = {