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Date: Mon, 9 Sep 2013 09:24:59 +0200
From: Benedikt Spranger <b.spranger@...utronix.de>
To: netdev@...r.kernel.org
Cc: Alexander Frank <Alexander.Frank@...rspaecher.com>,
Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
Holger Dengler <dengler@...utronix.de>,
Benedikt Spranger <b.spranger@...utronix.de>
Subject: [PATCH 02/16] c_can: add generic D-CAN RAM initialization support
D-CAN provides an automatic RAM initialization. The initialization can be
executed while D-CAN is in the init state.
It should be checked if this is compatible with TI's d_can implementation
which does not have or does not use this bit which is here according to the
d_can specification.
Signed-off-by: Benedikt Spranger <b.spranger@...utronix.de>
---
drivers/net/can/c_can/c_can.c | 38 ++++++++++++++++++++++++++++++++++++--
drivers/net/can/c_can/c_can.h | 2 ++
2 files changed, 38 insertions(+), 2 deletions(-)
diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index a668cd4..081620b 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -68,6 +68,8 @@
#define TEST_SILENT BIT(3)
#define TEST_BASIC BIT(2)
+#define FUNC_RAMINIT BIT(3)
+
/* status register */
#define STATUS_PDA BIT(10)
#define STATUS_BOFF BIT(7)
@@ -573,6 +575,7 @@ static int c_can_set_bittiming(struct net_device *dev)
u32 ten_bit_brp;
struct c_can_priv *priv = netdev_priv(dev);
const struct can_bittiming *bt = &priv->can.bittiming;
+ int retry;
/* c_can provides a 6-bit brp and 4-bit brpe fields */
ten_bit_brp = bt->brp - 1;
@@ -590,11 +593,42 @@ static int c_can_set_bittiming(struct net_device *dev)
"setting BTR=%04x BRPE=%04x\n", reg_btr, reg_brpe);
ctrl_save = priv->read_reg(priv, C_CAN_CTRL_REG);
- priv->write_reg(priv, C_CAN_CTRL_REG,
- ctrl_save | CONTROL_CCE | CONTROL_INIT);
+ ctrl_save &= ~CONTROL_INIT;
+
+ priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_CCE | CONTROL_INIT);
+ retry = 1000;
+ while (!(priv->read_reg(priv, C_CAN_CTRL_REG) & CONTROL_INIT)) {
+ if (!retry) {
+ netdev_info(dev, "CCTRL: set CONTROL_INIT failed\n");
+ return -EIO;
+ }
+ udelay(10);
+ retry--;
+ }
priv->write_reg(priv, C_CAN_BTR_REG, reg_btr);
priv->write_reg(priv, C_CAN_BRPEXT_REG, reg_brpe);
+
+ priv->write_reg(priv, C_CAN_FUNC_REG, FUNC_RAMINIT);
+ retry = 1000;
+ while (priv->read_reg(priv, C_CAN_FUNC_REG) & FUNC_RAMINIT) {
+ if (!retry) {
+ netdev_info(dev, "CFR: FUNC_RAMINIT failed\n");
+ return -EIO;
+ }
+ udelay(10);
+ retry--;
+ }
+
priv->write_reg(priv, C_CAN_CTRL_REG, ctrl_save);
+ retry = 1000;
+ while (priv->read_reg(priv, C_CAN_CTRL_REG) & CONTROL_INIT) {
+ if (!retry) {
+ netdev_info(dev, "CCTRL: clear CONTROL_INIT failed\n");
+ return -EIO;
+ }
+ udelay(10);
+ retry--;
+ }
return 0;
}
diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h
index d2e2d20..9f0eda8 100644
--- a/drivers/net/can/c_can/c_can.h
+++ b/drivers/net/can/c_can/c_can.h
@@ -61,6 +61,7 @@ enum reg {
C_CAN_INTPND2_REG,
C_CAN_MSGVAL1_REG,
C_CAN_MSGVAL2_REG,
+ C_CAN_FUNC_REG,
};
static const u16 reg_map_c_can[] = {
@@ -112,6 +113,7 @@ static const u16 reg_map_d_can[] = {
[C_CAN_BRPEXT_REG] = 0x0E,
[C_CAN_INT_REG] = 0x10,
[C_CAN_TEST_REG] = 0x14,
+ [C_CAN_FUNC_REG] = 0x18,
[C_CAN_TXRQST1_REG] = 0x88,
[C_CAN_TXRQST2_REG] = 0x8A,
[C_CAN_NEWDAT1_REG] = 0x9C,
--
1.8.4.rc3
--
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