[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20110805113638.GF4926@sgi.com>
Date: Fri, 5 Aug 2011 06:36:38 -0500
From: Robin Holt <holt@....com>
To: Marc Kleine-Budde <mkl@...gutronix.de>
Cc: Robin Holt <holt@....com>, Wolfgang Grandegger <wg@...ndegger.com>,
socketcan-core@...ts.berlios.de, netdev@...r.kernel.org
Subject: Re: [RFC 2/4] [flexcan] Introduce a flexcan_clk set of functions.
I implemented the coding style changes below (Sorry I missed the two
the first time).
As for a better implementation, I guess I would need to understand what
is being attempted here. I only marginally understand the flexcan
hardware on the Freescale P1010 and certainly am clueless about arm
implementations of flexcan. I just skimmed over freescale's site
and it looks like I would be looking at their i.MX25, i.MX28, i.MX35,
and i.MX53 family of processors. I will attempt to find some useful
documentation of those and look at the kernel sources for what the clk_*
functions are trying to accomplish.
I _THINK_ I understand. It looks like I could implement this as a powerpc
p1010 specific thing and get the same effect without impacting flexcan.c.
I also think I understand that the i.MX25 family of processors do
essentially the same thing the p1010 is doing for determining the
clock rate.
Thanks,
Robin
On Fri, Aug 05, 2011 at 10:34:11AM +0200, Marc Kleine-Budde wrote:
> On 08/05/2011 04:06 AM, Robin Holt wrote:
> > The freescale P1010RDB board does not have a
> > clk_{get,put,get_rate,enable,disable} set of functions. Wrap these with a
> > flexcan_ #define for arm, and implement a more complete function for ppc.
>
> Some codingstyle nitpicks inline. I hope we'll find a cleaner solution
> than this patch.
>
> Marc
>
> > Signed-off-by: Robin Holt <holt@....com>
> > To: Marc Kleine-Budde <mkl@...gutronix.de>
> > To: Wolfgang Grandegger <wg@...ndegger.com>
> > Cc: socketcan-core@...ts.berlios.de
> > Cc: netdev@...r.kernel.org
> > ---
> > drivers/net/can/flexcan.c | 114 +++++++++++++++++++++++++++++++++++++++++----
> > 1 files changed, 105 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
> > index 74b1706..3417d0b 100644
> > --- a/drivers/net/can/flexcan.c
> > +++ b/drivers/net/can/flexcan.c
> > @@ -220,6 +220,102 @@ static inline void flexcan_write(u32 val, void __iomem *addr)
> > }
> > #endif
> >
> > +#if defined(__powerpc__)
> > +struct flexcan_clk {
> > + unsigned long rate;
> > + void *data;
> > +};
> > +
> > +static struct clk *flexcan_clk_get(struct device *dev, const char *id)
> > +{
> > + struct flexcan_clk *clock;
> > + u32 *clock_freq;
> > + u32 *clock_divider;
> > + int err;
> > +
> > + clock = kmalloc(sizeof(struct flexcan_clk), GFP_KERNEL);
> > + if (!clock) {
> > + dev_err(dev, "Cannot allocate memory\n");
> > + err = -ENOMEM;
> > + goto failed_clock;
> > + }
> > + clock_freq = (u32 *)of_get_property(dev->of_node, "clock_freq", NULL);
> > + if (!clock_freq) {
> > + dev_err(dev, "Cannot find clock_freq property\n");
> > + err = -EINVAL;
> > + goto failed_clock;
> > + }
> > +
> > + clock_divider = (u32 *) of_get_property(dev->of_node,
> ^
>
> remove this space, please
> > + "fsl,flexcan-clock-divider", NULL);
> > + if (clock_divider == NULL) {
>
> !clock_divider
>
> > + dev_err(dev, "Cannot find fsl,flexcan-clock-divider property\n");
> > + err = -EINVAL;
> > + goto failed_clock;
> > + }
> > +
> > + clock->rate = DIV_ROUND_CLOSEST(*clock_freq / *clock_divider, 1000);
> > + clock->rate *= 1000;
> > +
> > + return (struct clk *)clock;
> > +
> > + failed_clock:
> > + kfree(clock);
> > + return ERR_PTR(err);
> > +}
> > +
> > +static inline void flexcan_clk_put(struct clk *_clk)
> > +{
> > + struct flexcan_clk *clk = (struct flexcan_clk *)_clk;
>
> that cast is not needed.
>
> > +
> > + kfree(clk);
> > +}
> > +
> > +static inline int flexcan_clk_enable(struct clk *clk)
> > +{
> > + return 0;
> > +}
> > +
> > +static inline void flexcan_clk_disable(struct clk *clk)
> > +{
> > + return;
> > +}
> > +
> > +static inline unsigned long flexcan_clk_get_rate(struct clk *_clk)
> > +{
> > + struct flexcan_clk *clk = (struct flexcan_clk *)_clk;
> > +
> > + return clk->rate;
> > +}
> > +
> > +#else
> > +static inline struct clk *flexcan_clk_get(struct device *dev, const char *id)
> > +{
> > + return clk_get(dev, id);
> > +}
> > +
> > +static inline void flexcan_clk_put(struct clk *clk)
> > +{
> > + clk_put(clk);
> > +}
> > +
> > +static inline int flexcan_clk_enable(struct clk *clk)
> > +{
> > + return clk_enable(clk);
> > +}
> > +
> > +static inline void flexcan_clk_disable(struct clk *clk)
> > +{
> > + clk_disable(clk);
> > +}
> > +
> > +static inline unsigned long flexcan_clk_get_rate(struct clk *clk)
> > +{
> > + return clk_get_rate(clk);
> > +}
> > +
> > +#endif
> > +
> > /*
> > * Swtich transceiver on or off
> > */
> > @@ -807,7 +903,7 @@ static int flexcan_open(struct net_device *dev)
> > struct flexcan_priv *priv = netdev_priv(dev);
> > int err;
> >
> > - clk_enable(priv->clk);
> > + flexcan_clk_enable(priv->clk);
> >
> > err = open_candev(dev);
> > if (err)
> > @@ -829,7 +925,7 @@ static int flexcan_open(struct net_device *dev)
> > out_close:
> > close_candev(dev);
> > out:
> > - clk_disable(priv->clk);
> > + flexcan_clk_disable(priv->clk);
> >
> > return err;
> > }
> > @@ -843,7 +939,7 @@ static int flexcan_close(struct net_device *dev)
> > flexcan_chip_stop(dev);
> >
> > free_irq(dev->irq, dev);
> > - clk_disable(priv->clk);
> > + flexcan_clk_disable(priv->clk);
> >
> > close_candev(dev);
> >
> > @@ -882,7 +978,7 @@ static int __devinit register_flexcandev(struct net_device *dev)
> > struct flexcan_regs __iomem *regs = priv->base;
> > u32 reg, err;
> >
> > - clk_enable(priv->clk);
> > + flexcan_clk_enable(priv->clk);
> >
> > /* select "bus clock", chip must be disabled */
> > flexcan_chip_disable(priv);
> > @@ -916,7 +1012,7 @@ static int __devinit register_flexcandev(struct net_device *dev)
> > out:
> > /* disable core and turn off clocks */
> > flexcan_chip_disable(priv);
> > - clk_disable(priv->clk);
> > + flexcan_clk_disable(priv->clk);
> >
> > return err;
> > }
> > @@ -936,7 +1032,7 @@ static int __devinit flexcan_probe(struct platform_device *pdev)
> > resource_size_t mem_size;
> > int err, irq;
> >
> > - clk = clk_get(&pdev->dev, NULL);
> > + clk = flexcan_clk_get(&pdev->dev, NULL);
> > if (IS_ERR(clk)) {
> > dev_err(&pdev->dev, "no clock defined\n");
> > err = PTR_ERR(clk);
> > @@ -973,7 +1069,7 @@ static int __devinit flexcan_probe(struct platform_device *pdev)
> > dev->flags |= IFF_ECHO; /* we support local echo in hardware */
> >
> > priv = netdev_priv(dev);
> > - priv->can.clock.freq = clk_get_rate(clk);
> > + priv->can.clock.freq = flexcan_clk_get_rate(clk);
> > priv->can.bittiming_const = &flexcan_bittiming_const;
> > priv->can.do_set_mode = flexcan_set_mode;
> > priv->can.do_get_berr_counter = flexcan_get_berr_counter;
> > @@ -1008,7 +1104,7 @@ static int __devinit flexcan_probe(struct platform_device *pdev)
> > failed_map:
> > release_mem_region(mem->start, mem_size);
> > failed_get:
> > - clk_put(clk);
> > + flexcan_clk_put(clk);
> > failed_clock:
> > return err;
> > }
> > @@ -1026,7 +1122,7 @@ static int __devexit flexcan_remove(struct platform_device *pdev)
> > mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > release_mem_region(mem->start, resource_size(mem));
> >
> > - clk_put(priv->clk);
> > + flexcan_clk_put(priv->clk);
> >
> > free_candev(dev);
> >
>
>
> --
> 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 |
>
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists