Subject: Re: [PATCH v2 1/3] can: sja1000: of: add per-compatible init hook

From: Damien Riegel <[email-masked]>
Date: Tue, 12 Jan 2016 10:53:30 -0500

On Tue, Jan 12, 2016 at 08:52:06AM +0100, Marc Kleine-Budde wrote:
> On 12/24/2015 06:42 PM, Damien Riegel wrote:
> > This commit adds the capability to allocate and init private data
> > embedded in the sja1000_priv structure on a per-compatible basis. The
> > device node is passed as a parameter of the init callback to allow
> > parsing of custom device tree properties.
> > 
> > Signed-off-by: Damien Riegel <[email-masked]>
> > ---
> >  drivers/net/can/sja1000/sja1000_platform.c | 39 ++++++++++++++++++++++++++++--
> >  1 file changed, 37 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/net/can/sja1000/sja1000_platform.c b/drivers/net/can/sja1000/sja1000_platform.c
> > index 0552ed4..e0572d0 100644
> > --- a/drivers/net/can/sja1000/sja1000_platform.c
> > +++ b/drivers/net/can/sja1000/sja1000_platform.c
> > @@ -40,6 +40,11 @@ MODULE_DESCRIPTION("Socket-CAN driver for SJA1000 on the platform bus");
> >  MODULE_ALIAS("platform:" DRV_NAME);
> >  MODULE_LICENSE("GPL v2");
> >  
> > +struct sja1000_of_data {
> > +	size_t  priv_sz;
> > +	int     (*init)(struct sja1000_priv *priv, struct device_node *of);
> > +};
> > +
> >  static u8 sp_read_reg8(const struct sja1000_priv *priv, int reg)
> >  {
> >  	return ioread8(priv->reg_base + reg);
> > @@ -154,7 +159,8 @@ static void sp_populate_of(struct sja1000_priv *priv, struct device_node *of)
> >  		priv->cdr |= CDR_CBP; /* default */
> >  }
> >  
> > -static int sp_probe(struct platform_device *pdev)
> > +static int __sp_probe(struct platform_device *pdev,
> > +		      const struct sja1000_of_data *of_data)
> >  {
> >  	int err, irq = 0;
> >  	void __iomem *addr;
> > @@ -163,6 +169,7 @@ static int sp_probe(struct platform_device *pdev)
> >  	struct resource *res_mem, *res_irq = NULL;
> >  	struct sja1000_platform_data *pdata;
> >  	struct device_node *of = pdev->dev.of_node;
> > +	size_t priv_sz = of_data ? of_data->priv_sz : 0;
> >  
> >  	pdata = dev_get_platdata(&pdev->dev);
> >  	if (!pdata && !of) {
> > @@ -191,7 +198,7 @@ static int sp_probe(struct platform_device *pdev)
> >  	if (!irq && !res_irq)
> >  		return -ENODEV;
> >  
> > -	dev = alloc_sja1000dev(0);
> > +	dev = alloc_sja1000dev(priv_sz);
> >  	if (!dev)
> >  		return -ENOMEM;
> >  	priv = netdev_priv(dev);
> > @@ -213,6 +220,12 @@ static int sp_probe(struct platform_device *pdev)
> >  	else
> >  		sp_populate(priv, pdata, res_mem->flags);
> >  
> > +	if (of_data && of_data->init) {
> > +		err = of_data->init(priv, of);
> > +		if (err)
> > +			goto exit_free;
> > +	}
> > +
> >  	platform_set_drvdata(pdev, dev);
> >  	SET_NETDEV_DEV(dev, &pdev->dev);
> >  
> > @@ -248,6 +261,28 @@ static const struct of_device_id sp_of_table[] = {
> >  };
> >  MODULE_DEVICE_TABLE(of, sp_of_table);
> >  
> > +static const struct sja1000_of_data *sp_get_of_data(struct device_node *of)
> > +{
> > +	const struct of_device_id *id;
> > +
> > +	if (!of)
> > +		return NULL;
> > +
> > +	id = of_match_node(sp_of_table, of);
> > +	if (!id)
> > +		return NULL;
> > +
> > +	return id->data;
> > +}
> > +
> > +static int sp_probe(struct platform_device *pdev)
> > +{
> > +	struct device_node *of = pdev->dev.of_node;
> > +	const struct sja1000_of_data *of_data = sp_get_of_data(of);
> > +
> > +	return __sp_probe(pdev, of_data);
> > +}
> 
> Please merge these two into the original sp_probe function, as there
> already is a test for pdev->dev.of_node.

Ok. sp_get_of_data makes use of sp_of_table, so either I move sp_probe
below sp_of_table, or I use a forward declaration. Which one do you
prefer?

Damien