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Subject[PATCHv2] net: c_can: Add support for D_CAN Module RAM Init
Date
From: Thor Thayer <tthayer@altera.com>

The D_CAN driver was written to support the TI D_CAN implementation
which placed the D_CAN RAM reset in a separate register. In the
standard D_CAN module the RAM Init is in the D_CAN module so
handle the RAM Init differently.
This patch has only been tested on the standard D_CAN module (but not
on the TI D_CAN module).

Signed-off-by: Thor Thayer <tthayer@altera.com>
---
Changes in v2:
-Rename raminit_type_flag to raminit_type
-New constants for raminit_type
---
---
drivers/net/can/c_can/c_can.h | 3 ++
drivers/net/can/c_can/c_can_platform.c | 51 +++++++++++++++++++++++++-------
2 files changed, 44 insertions(+), 10 deletions(-)

diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h
index faa8404..73c6c88 100644
--- a/drivers/net/can/c_can/c_can.h
+++ b/drivers/net/can/c_can/c_can.h
@@ -88,6 +88,7 @@ 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[] = {
@@ -139,6 +140,7 @@ 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,
@@ -201,6 +203,7 @@ struct c_can_priv {
unsigned int instance;
void (*raminit) (const struct c_can_priv *priv, bool enable);
u32 dlc[C_CAN_MSG_OBJ_TX_NUM];
+ u32 raminit_type;
};

struct net_device *alloc_c_can_dev(void);
diff --git a/drivers/net/can/c_can/c_can_platform.c b/drivers/net/can/c_can/c_can_platform.c
index 806d927..af3366f 100644
--- a/drivers/net/can/c_can/c_can_platform.c
+++ b/drivers/net/can/c_can/c_can_platform.c
@@ -41,6 +41,14 @@
#define CAN_RAMINIT_DONE_MASK(i) (0x100 << (i))
#define CAN_RAMINIT_ALL_MASK(i) (0x101 << (i))
static DEFINE_SPINLOCK(raminit_lock);
+#define DCAN_RAM_INIT_BIT (1 << 3)
+struct c_can_ram_init_masks {
+ u32 start;
+ u32 done;
+ u32 all;
+};
+#define CAN_RAMINIT_TYPE_STANDARD 0
+#define CAN_RAMINIT_TYPE_TI 1
/*
* 16-bit c_can registers can be arranged differently in the memory
* architecture of different implementations. For example: 16-bit
@@ -82,9 +90,19 @@ static void c_can_hw_raminit_wait(const struct c_can_priv *priv, u32 mask,

static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable)
{
- u32 mask = CAN_RAMINIT_ALL_MASK(priv->instance);
+ struct c_can_ram_init_masks ram_init_masks;
u32 ctrl;

+ if (priv->raminit_type == CAN_RAMINIT_TYPE_TI) {
+ ram_init_masks.start = CAN_RAMINIT_START_MASK(priv->instance);
+ ram_init_masks.done = CAN_RAMINIT_DONE_MASK(priv->instance);
+ ram_init_masks.all = CAN_RAMINIT_ALL_MASK(priv->instance);
+ } else {
+ ram_init_masks.start = DCAN_RAM_INIT_BIT;
+ ram_init_masks.done = 0;
+ ram_init_masks.all = 0;
+ }
+
spin_lock(&raminit_lock);

ctrl = readl(priv->raminit_ctrlreg);
@@ -92,18 +110,18 @@ static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable)
* looking at the 0 -> transition, but is not self clearing;
* And we clear the init done bit as well.
*/
- ctrl &= ~CAN_RAMINIT_START_MASK(priv->instance);
- ctrl |= CAN_RAMINIT_DONE_MASK(priv->instance);
+ ctrl &= ~ram_init_masks.start;
+ ctrl |= ram_init_masks.done;
writel(ctrl, priv->raminit_ctrlreg);
- ctrl &= ~CAN_RAMINIT_DONE_MASK(priv->instance);
- c_can_hw_raminit_wait(priv, ctrl, mask);
+ ctrl &= ~ram_init_masks.done;
+ c_can_hw_raminit_wait(priv, ctrl, ram_init_masks.all);

if (enable) {
/* Set start bit and wait for the done bit. */
- ctrl |= CAN_RAMINIT_START_MASK(priv->instance);
+ ctrl |= ram_init_masks.start;
writel(ctrl, priv->raminit_ctrlreg);
- ctrl |= CAN_RAMINIT_DONE_MASK(priv->instance);
- c_can_hw_raminit_wait(priv, ctrl, mask);
+ ctrl |= ram_init_masks.done;
+ c_can_hw_raminit_wait(priv, ctrl, ram_init_masks.all);
}
spin_unlock(&raminit_lock);
}
@@ -221,11 +239,24 @@ 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_type = CAN_RAMINIT_TYPE_STANDARD;
+ 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) || (int)priv->instance < 0)
+ if (IS_ERR(priv->raminit_ctrlreg) || (int)priv->instance < 0) {
dev_info(&pdev->dev, "control memory is not used for raminit\n");
- else
+ } else {
priv->raminit = c_can_hw_raminit;
+ priv->raminit_type = CAN_RAMINIT_TYPE_TI;
+ }
break;
default:
ret = -EINVAL;
--
1.7.9.5


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