[PATCH 1/2] hwinit support for non-TI devices

[Pavel Machek]

Non-TI chips (including socfpga) needs different raminit
sequence. Implement it.

Tested-by: Thor Thayer <tthayer at altera.com>
Signed-off-by: Thor Thayer <tthayer at altera.com>
Signed-off-by: Pavel Machek <pavel at denx.de>

diff --git a/drivers/net/can/c_can/c_can_platform.c b/drivers/net/can/c_can/c_can_platform.c
index 1df0b32..476d1e0 100644
--- a/drivers/net/can/c_can/c_can_platform.c
+++ b/drivers/net/can/c_can/c_can_platform.c
@@ -40,6 +40,7 @@
 #define CAN_RAMINIT_START_MASK(i)	(0x001 << (i))
 #define CAN_RAMINIT_DONE_MASK(i)	(0x100 << (i))
 #define CAN_RAMINIT_ALL_MASK(i)		(0x101 << (i))
+#define DCAN_RAM_INIT_BIT	(1 << 3)
 static DEFINE_SPINLOCK(raminit_lock);
 /*
  * 16-bit c_can registers can be arranged differently in the memory
@@ -80,7 +81,7 @@ static void c_can_hw_raminit_wait(const struct c_can_priv *priv, u32 mask,
 		udelay(1);
 }
 
-static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable)
+static void c_can_hw_raminit_ti(const struct c_can_priv *priv, bool enable)
 {
 	u32 mask = CAN_RAMINIT_ALL_MASK(priv->instance);
 	u32 ctrl;
@@ -88,7 +89,8 @@ static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable)
 	spin_lock(&raminit_lock);
 
 	ctrl = readl(priv->raminit_ctrlreg);
-	/* We clear the done and start bit first. The start bit is
+	/*
+	 * We clear the done and start bit first. The start bit is
 	 * looking at the 0 -> transition, but is not self clearing;
 	 * And we clear the init done bit as well.
 	 */
@@ -108,6 +110,54 @@ static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable)
 	spin_unlock(&raminit_lock);
 }
 
+static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable)
+{
+	u32 ctrl;
+
+	spin_lock(&raminit_lock);
+
+	ctrl = readl(priv->raminit_ctrlreg);
+	ctrl &= ~DCAN_RAM_INIT_BIT;
+	writel(ctrl, priv->raminit_ctrlreg);
+	c_can_hw_raminit_wait(priv, ctrl, 0);
+
+	if (enable) {
+		/* Set start bit. */
+		ctrl |= DCAN_RAM_INIT_BIT;
+		writel(ctrl, priv->raminit_ctrlreg);
+		c_can_hw_raminit_wait(priv, ctrl, 0);
+	}
+	spin_unlock(&raminit_lock);
+}
+
+static u32 c_can_plat_read_reg32(struct c_can_priv *priv, enum reg index)
+{
+	u32 val;
+
+	val = priv->read_reg(priv, index);
+	val |= ((u32) priv->read_reg(priv, index + 1)) << 16;
+
+	return val;
+}
+
+static void c_can_plat_write_reg32(struct c_can_priv *priv, enum reg index,
+		u32 val)
+{
+	priv->write_reg(priv, index + 1, val>>16);
+	priv->write_reg(priv, index, val);
+}
+
+static u32 d_can_plat_read_reg32(struct c_can_priv *priv, enum reg index)
+{
+	return readl(priv->base + priv->regs[index]);
+}
+
+static void d_can_plat_write_reg32(struct c_can_priv *priv, enum reg index,
+		u32 val)
+{
+	writel(val, priv->base + priv->regs[index]);
+}
+
 static struct platform_device_id c_can_id_table[] = {
 	[BOSCH_C_CAN_PLATFORM] = {
 		.name = KBUILD_MODNAME,
@@ -201,11 +251,15 @@ static int c_can_plat_probe(struct platform_device *pdev)
 		case IORESOURCE_MEM_32BIT:
 			priv->read_reg = c_can_plat_read_reg_aligned_to_32bit;
 			priv->write_reg = c_can_plat_write_reg_aligned_to_32bit;
+			priv->read_reg32 = c_can_plat_read_reg32;
+			priv->write_reg32 = c_can_plat_write_reg32;
 			break;
 		case IORESOURCE_MEM_16BIT:
 		default:
 			priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
 			priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
+			priv->read_reg32 = c_can_plat_read_reg32;
+			priv->write_reg32 = c_can_plat_write_reg32;
 			break;
 		}
 		break;
@@ -214,6 +268,8 @@ static int c_can_plat_probe(struct platform_device *pdev)
 		priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
 		priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
 		priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
+		priv->read_reg32 = d_can_plat_read_reg32;
+		priv->write_reg32 = d_can_plat_write_reg32;
 
 		if (pdev->dev.of_node)
 			priv->instance = of_alias_get_id(pdev->dev.of_node, "d_can");
@@ -221,11 +277,22 @@ static int c_can_plat_probe(struct platform_device *pdev)
 			priv->instance = pdev->id;
 
 		res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+		/*
+		 * Not all D_CAN module have a separate register for the D_CAN
+		 * RAM initialization. Use default RAM init bit in D_CAN module
+		 * if not specified in DT.
+		 */
+		if (!res) {
+			priv->raminit = c_can_hw_raminit;
+			priv->raminit_ctrlreg = addr + priv->regs[C_CAN_FUNCTION_REG];
+			break;
+		}
+
 		priv->raminit_ctrlreg = devm_ioremap_resource(&pdev->dev, res);
 		if (IS_ERR(priv->raminit_ctrlreg) || priv->instance < 0)
 			dev_info(&pdev->dev, "control memory is not used for raminit\n");
 		else
-			priv->raminit = c_can_hw_raminit;
+			priv->raminit = c_can_hw_raminit_ti;
 		break;
 	default:
 		ret = -EINVAL;