can: c_can: Add d_can raminit support

Add D_CAN raminit support to C_CAN driver to enable D_CAN RAM,
which holds all the message objects during transmission or
receiving of data. This initialization/de-initialization should
be done in synchronous with D_CAN clock.

In case of AM335X-EVM (current user of D_CAN driver) message RAM is
controlled through control module register for both instances. So
control module register details is required to initialization or
de-initialization of message RAM according to instance number.

Control module memory resource is obtained from D_CAN dt node and
instance number obtained from device tree aliases node.

This patch was tested on AM335x-EVM along with pinctrl data addition
patch, d_can dt aliases addition and control module data addition.
pinctrl data addition is not added to am335x-evm.dts (only supports
CPLD profile#0) because d_can1 is supported under CPLD profile#1.

Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
[mkl: fix instance for non DT in probe, cleaned up raminit]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
index e5180dfd..5233b8f 100644
--- a/drivers/net/can/c_can/c_can.c
+++ b/drivers/net/can/c_can/c_can.c
@@ -233,6 +233,12 @@
 		pm_runtime_put_sync(priv->device);
 }
 
+static inline void c_can_reset_ram(const struct c_can_priv *priv, bool enable)
+{
+	if (priv->raminit)
+		priv->raminit(priv, enable);
+}
+
 static inline int get_tx_next_msg_obj(const struct c_can_priv *priv)
 {
 	return (priv->tx_next & C_CAN_NEXT_MSG_OBJ_MASK) +
@@ -1090,6 +1096,7 @@
 	struct c_can_priv *priv = netdev_priv(dev);
 
 	c_can_pm_runtime_get_sync(priv);
+	c_can_reset_ram(priv, true);
 
 	/* open the can device */
 	err = open_candev(dev);
@@ -1118,6 +1125,7 @@
 exit_irq_fail:
 	close_candev(dev);
 exit_open_fail:
+	c_can_reset_ram(priv, false);
 	c_can_pm_runtime_put_sync(priv);
 	return err;
 }
@@ -1131,6 +1139,8 @@
 	c_can_stop(dev);
 	free_irq(dev->irq, dev);
 	close_candev(dev);
+
+	c_can_reset_ram(priv, false);
 	c_can_pm_runtime_put_sync(priv);
 
 	return 0;
@@ -1188,6 +1198,7 @@
 
 	c_can_stop(dev);
 
+	c_can_reset_ram(priv, false);
 	c_can_pm_runtime_put_sync(priv);
 
 	return 0;
@@ -1206,6 +1217,7 @@
 	WARN_ON(priv->type != BOSCH_D_CAN);
 
 	c_can_pm_runtime_get_sync(priv);
+	c_can_reset_ram(priv, true);
 
 	/* Clear PDR and INIT bits */
 	val = priv->read_reg(priv, C_CAN_CTRL_EX_REG);