[PATCH v2] can: c_can: Add d_can raminit support

[AnilKumar, Chimata]

On Wed, Nov 21, 2012 at 13:57:17, Marc Kleine-Budde wrote:
> On 11/21/2012 06:44 AM, AnilKumar Ch wrote:
> > 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 at ti.com>
> > ---
> > Changes from v1:
> > 	- Incorporated Marc's comments on v1
> > 	  * sanity check moved to c_can_probe() from c_can_hw_raminit()
> > 	  * device instance is assigned using conditional operator
> > 	  * Changed warning to info to tell control module is not
> > 	    used for raminit if there is no second IORESOURCE_MEM
> > 	- Dropped dt patches
> > 	  * No changes from v1
> > 	  * Those will go to linux-omap/master
> > 
> >  drivers/net/can/c_can/c_can.c          |   12 ++++++++++++
> >  drivers/net/can/c_can/c_can.h          |    3 +++
> >  drivers/net/can/c_can/c_can_platform.c |   33 +++++++++++++++++++++++++++++++-
> >  3 files changed, 47 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
> > index e5180df..c15830c 100644
> > --- a/drivers/net/can/c_can/c_can.c
> > +++ b/drivers/net/can/c_can/c_can.c
> > @@ -233,6 +233,12 @@ static inline void c_can_pm_runtime_put_sync(const struct c_can_priv *priv)
> >  		pm_runtime_put_sync(priv->device);
> >  }
> >  
> > +static inline void c_can_reset_ram(const struct c_can_priv *priv, bool enable)
> > +{
> > +	if (priv->ram_init)
> > +		priv->ram_init(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 @@ static int c_can_open(struct net_device *dev)
> >  	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 @@ static int c_can_open(struct net_device *dev)
> >  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 @@ static int c_can_close(struct net_device *dev)
> >  	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 @@ int c_can_power_down(struct net_device *dev)
> >  
> >  	c_can_stop(dev);
> >  
> > +	c_can_reset_ram(priv, false);
> >  	c_can_pm_runtime_put_sync(priv);
> >  
> >  	return 0;
> > @@ -1206,6 +1217,7 @@ int c_can_power_up(struct net_device *dev)
> >  	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);
> > diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h
> > index e5ed41d..419de5c 100644
> > --- a/drivers/net/can/c_can/c_can.h
> > +++ b/drivers/net/can/c_can/c_can.h
> > @@ -169,6 +169,9 @@ struct c_can_priv {
> >  	void *priv;		/* for board-specific data */
> >  	u16 irqstatus;
> >  	enum c_can_dev_id type;
> > +	u32 __iomem *raminit_ctrlreg;
> > +	unsigned int instance;
> > +	void (*ram_init) (const struct c_can_priv *priv, bool enable);
> >  };
> >  
> >  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 ee141613..d1c31c8 100644
> > --- a/drivers/net/can/c_can/c_can_platform.c
> > +++ b/drivers/net/can/c_can/c_can_platform.c
> > @@ -38,6 +38,8 @@
> >  
> >  #include "c_can.h"
> >  
> > +#define CAN_RAMINIT_START_MASK(i)	(1 << (i))
> > +
> >  /*
> >   * 16-bit c_can registers can be arranged differently in the memory
> >   * architecture of different implementations. For example: 16-bit
> > @@ -68,6 +70,21 @@ static void c_can_plat_write_reg_aligned_to_32bit(struct c_can_priv *priv,
> >  	writew(val, priv->base + 2 * priv->regs[index]);
> >  }
> >  
> > +static void c_can_hw_raminit(const struct c_can_priv *priv, bool enable)
> > +{
> > +	u32 val;
> > +
> > +	val = readl(priv->raminit_ctrlreg);
> > +	if (enable) {
> > +		val &= ~CAN_RAMINIT_START_MASK(priv->instance);
> 
> What's the point of clearing the bit first?
> 
> > +		val |= CAN_RAMINIT_START_MASK(priv->instance);
> > +		writel(val, priv->raminit_ctrlreg);
> > +	} else {
> > +		val &= ~CAN_RAMINIT_START_MASK(priv->instance);
> > +		writel(val, priv->raminit_ctrlreg);
> > +	}
> 
> This should do the same?
> 
> 	if (enable)
> 		val |= CAN_RAMINIT_START_MASK(priv->instance);
> 	else
> 		val &= ~CAN_RAMINIT_START_MASK(priv->instance);
> 	writel(val, priv->raminit_ctrlreg);
> 
> I can add the changes while applying the patch.

Thanks Marc.

Thanks
AnilKumar