can: c_can: add hwinit support for non-TI devices

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

Tested-by: Thor Thayer <tthayer@altera.com>
Signed-off-by: Thor Thayer <tthayer@altera.com>
Signed-off-by: Pavel Machek <pavel@denx.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

2 files changed, 38 insertions, 4 deletions

diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h
index 44433e1ebe00..99ad1aa576b0 100644
--- a/drivers/net/can/c_can/c_can.h
+++ b/drivers/net/can/c_can/c_can.h
@@ -78,6 +78,7 @@ enum reg {
         C_CAN_INTPND2_REG,
         C_CAN_MSGVAL1_REG,
         C_CAN_MSGVAL2_REG,
+        C_CAN_FUNCTION_REG,
 };
 
 static const u16 reg_map_c_can[] = {
@@ -129,6 +130,7 @@ static const u16 reg_map_d_can[] = {
         [C_CAN_BRPEXT_REG]      = 0x0E,
         [C_CAN_INT_REG]         = 0x10,
         [C_CAN_TEST_REG]        = 0x14,
+        [C_CAN_FUNCTION_REG]    = 0x18,
         [C_CAN_TXRQST1_REG]     = 0x88,
         [C_CAN_TXRQST2_REG]     = 0x8A,
         [C_CAN_NEWDAT1_REG]     = 0x9C,
diff --git a/drivers/net/can/c_can/c_can_platform.c b/drivers/net/can/c_can/c_can_platform.c
index 0db3625b691f..824108cd9fd5 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_ti(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;
@@ -96,14 +97,14 @@ static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable)
         ctrl |= CAN_RAMINIT_DONE_MASK(priv->instance);
         writel(ctrl, priv->raminit_ctrlreg);
         ctrl &= ~CAN_RAMINIT_DONE_MASK(priv->instance);
-        c_can_hw_raminit_wait(priv, ctrl, mask);
+        c_can_hw_raminit_wait_ti(priv, ctrl, mask);
 
         if (enable) {
                 /* Set start bit and wait for the done bit. */
                 ctrl |= CAN_RAMINIT_START_MASK(priv->instance);
                 writel(ctrl, priv->raminit_ctrlreg);
                 ctrl |= CAN_RAMINIT_DONE_MASK(priv->instance);
-                c_can_hw_raminit_wait(priv, ctrl, mask);
+                c_can_hw_raminit_wait_ti(priv, ctrl, mask);
         }
         spin_unlock(&raminit_lock);
 }
@@ -136,6 +137,28 @@ static void d_can_plat_write_reg32(const struct c_can_priv *priv, enum reg index
         writel(val, priv->base + priv->regs[index]);
 }
 
+static void c_can_hw_raminit_wait(const struct c_can_priv *priv, u32 mask)
+{
+        while (priv->read_reg32(priv, C_CAN_FUNCTION_REG) & mask)
+                udelay(1);
+}
+
+static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable)
+{
+        u32 ctrl;
+
+        ctrl = priv->read_reg32(priv, C_CAN_FUNCTION_REG);
+        ctrl &= ~DCAN_RAM_INIT_BIT;
+        priv->write_reg32(priv, C_CAN_FUNCTION_REG, ctrl);
+        c_can_hw_raminit_wait(priv, ctrl);
+
+        if (enable) {
+                ctrl |= DCAN_RAM_INIT_BIT;
+                priv->write_reg32(priv, C_CAN_FUNCTION_REG, ctrl);
+                c_can_hw_raminit_wait(priv, ctrl);
+        }
+}
+
 static struct platform_device_id c_can_id_table[] = {
         [BOSCH_C_CAN_PLATFORM] = {
                 .name = KBUILD_MODNAME,
@@ -255,11 +278,20 @@ 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 modules 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;
+                        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;