[PATCH 2/4] can: c_can: Add d_can raminit support

AnilKumar, Chimata anilkumar at ti.com
Tue Sep 4 02:14:21 EDT 2012


Hi Marc,

On Tue, Sep 04, 2012 at 02:09:15, Marc Kleine-Budde wrote:
> On 09/03/2012 01:52 PM, AnilKumar Ch wrote:
> > Add D_CAN raminit support to C_CAN driver to enable D_CAN RAM.
> > DCAN RAM holds all the message objects during transmission or
> > receiving of data. This initialization/de-initialization should
> > be done in synchronous with D_CAN clock.
> > 
> > Signed-off-by: AnilKumar Ch <anilkumar at ti.com>
> > ---
> >  drivers/net/can/c_can/c_can.c          |   13 ++++++++++++
> >  drivers/net/can/c_can/c_can.h          |    2 ++
> >  drivers/net/can/c_can/c_can_platform.c |   10 +++++++++
> >  include/linux/can/platform/c_can.h     |   36 ++++++++++++++++++++++++++++++++
> >  4 files changed, 61 insertions(+)
> >  create mode 100644 include/linux/can/platform/c_can.h
> > 
> > diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c
> > index aa6c5eb..c175410 100644
> > --- a/drivers/net/can/c_can/c_can.c
> > +++ b/drivers/net/can/c_can/c_can.c
> > @@ -214,6 +214,12 @@ 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->instance, 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) +
> > @@ -1071,6 +1077,8 @@ static int c_can_open(struct net_device *dev)
> >  	struct c_can_priv *priv = netdev_priv(dev);
> >  
> >  	c_can_pm_runtime_get_sync(priv);
> > +	/* Initialize DCAN RAM */
> > +	c_can_reset_ram(priv, true);
> >  
> >  	/* open the can device */
> >  	err = open_candev(dev);
> > @@ -1099,6 +1107,8 @@ static int c_can_open(struct net_device *dev)
> >  exit_irq_fail:
> >  	close_candev(dev);
> >  exit_open_fail:
> > +	/* De-Initialize DCAN RAM */
> > +	c_can_reset_ram(priv, false);
> >  	c_can_pm_runtime_put_sync(priv);
> >  	return err;
> >  }
> > @@ -1112,6 +1122,9 @@ static int c_can_close(struct net_device *dev)
> >  	c_can_stop(dev);
> >  	free_irq(dev->irq, dev);
> >  	close_candev(dev);
> > +
> > +	/* De-Initialize DCAN RAM */
> > +	c_can_reset_ram(priv, false);
> >  	c_can_pm_runtime_put_sync(priv);
> >  
> >  	return 0;
> > diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h
> > index 1437a6d..5f6339c 100644
> > --- a/drivers/net/can/c_can/c_can.h
> > +++ b/drivers/net/can/c_can/c_can.h
> > @@ -166,6 +166,8 @@ struct c_can_priv {
> >  	unsigned int tx_echo;
> >  	void *priv;		/* for board-specific data */
> >  	u16 irqstatus;
> > +	unsigned int instance;
> > +	void (*ram_init) (unsigned int instance, 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 c351975..c6963b2 100644
> > --- a/drivers/net/can/c_can/c_can_platform.c
> > +++ b/drivers/net/can/c_can/c_can_platform.c
> > @@ -34,6 +34,7 @@
> >  #include <linux/of_device.h>
> >  #include <linux/pm_runtime.h>
> >  #include <linux/pinctrl/consumer.h>
> > +#include <linux/can/platform/c_can.h>
> >  
> >  #include <linux/can/dev.h>
> >  
> > @@ -98,6 +99,7 @@ static int __devinit c_can_plat_probe(struct platform_device *pdev)
> >  	struct net_device *dev;
> >  	struct c_can_priv *priv;
> >  	const struct of_device_id *match;
> > +	struct c_can_platform_data *pdata = NULL;
> >  	const struct platform_device_id *id;
> >  	struct pinctrl *pinctrl;
> >  	struct resource *mem;
> > @@ -179,6 +181,14 @@ static int __devinit c_can_plat_probe(struct platform_device *pdev)
> >  		priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
> >  		priv->read_reg = c_can_plat_read_reg_aligned_to_16bit;
> >  		priv->write_reg = c_can_plat_write_reg_aligned_to_16bit;
> > +		pdata = pdev->dev.platform_data;
> > +		if (!pdata) {
> > +			dev_err(&pdev->dev, "d_can platform data missing\n");
> > +			ret = -EINVAL;
> 
> Is the ram_init mandatory on all d_can? There might be non omap d_can users.

As per AM335x specifications d_can module should have ram_init.
In that case it's better to print warning and break the switch.

> 
> Marc
> 
> > +			goto exit_free_device;
> > +		}
> > +		priv->ram_init = pdata->ram_init;
> > +		priv->instance = pdata->instance;
> >  		break;
> >  	default:
> >  		ret = -EINVAL;
> > diff --git a/include/linux/can/platform/c_can.h b/include/linux/can/platform/c_can.h
> > new file mode 100644
> > index 0000000..84b27d2
> > --- /dev/null
> > +++ b/include/linux/can/platform/c_can.h
> > @@ -0,0 +1,36 @@
> > +/*
> > + * C_CAN controller driver platform header
> > + *
> > + * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/
> > + *
> > + * Bosch C_CAN/D_CAN controller is compliant to CAN protocol version 2.0
> > + * part A and B.
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU General Public License as
> > + * published by the Free Software Foundation version 2.
> > + *
> > + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
> > + * kind, whether express or implied; without even the implied warranty
> > + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > + * GNU General Public License for more details.
> > + */
> > +
> > +#ifndef __CAN_PLATFORM_C_CAN_H__
> > +#define __CAN_PLATFORM_C_CAN_H__
> > +
> > +/**
> > + * struct c_can_platform_data - C_CAN/D_CAN Platform Data
> > + *
> > + * @instance:		CAN instance, required for d_can raminit
> > + * @ram_init:		CAN RAM initialization
> > + *
> > + * Platform data structure to get all platform specific settings.
> > + * this structure also accounts the fact that the IP may have different
> > + * RAM for different SOC's
> > + */
> > +struct c_can_platform_data {
> > +	unsigned int instance;
> > +	void (*ram_init) (unsigned int instance, bool enable);
> > +};
> > +#endif
> > 
> 
> 
> -- 
> Pengutronix e.K.                  | Marc Kleine-Budde           |
> Industrial Linux Solutions        | Phone: +49-231-2826-924     |
> Vertretung West/Dortmund          | Fax:   +49-5121-206917-5555 |
> Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |
> 
> 




More information about the linux-arm-kernel mailing list