Re: [PATCH v2 net-next] net: dsa: b53: mmap: Add device tree support

[Jakub Kicinski]

On Mon, 15 Mar 2021 16:11:40 +0100 Álvaro Fernández Rojas wrote:
> Add device tree support to b53_mmap.c while keeping platform devices support.
> 
> Signed-off-by: Álvaro Fernández Rojas <nolt...@gmail.com>
> ---
>  v2: add change suggested by Florian Fainelli (less "OF-centric") and replace
>   brcm,ports property with a ports child scan.
> 
>  drivers/net/dsa/b53/b53_mmap.c | 54 ++++++++++++++++++++++++++++++++++
>  1 file changed, 54 insertions(+)
> 
> diff --git a/drivers/net/dsa/b53/b53_mmap.c b/drivers/net/dsa/b53/b53_mmap.c
> index c628d0980c0b..94a4e3929ebf 100644
> --- a/drivers/net/dsa/b53/b53_mmap.c
> +++ b/drivers/net/dsa/b53/b53_mmap.c
> @@ -16,6 +16,7 @@
>   * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
>   */
>  
> +#include <linux/bits.h>
>  #include <linux/kernel.h>
>  #include <linux/module.h>
>  #include <linux/io.h>
> @@ -228,11 +229,64 @@ static const struct b53_io_ops b53_mmap_ops = {
>       .write64 = b53_mmap_write64,
>  };
>  
> +static int b53_mmap_probe_of(struct platform_device *pdev,
> +                          struct b53_platform_data **ppdata)
> +{
> +     struct device *dev = &pdev->dev;
> +     struct device_node *np = dev->of_node;
> +     struct device_node *of_ports, *of_port;
> +     struct b53_platform_data *pdata;
> +     void __iomem *mem;

reverse xmas tree? Initialize out of line if needed.

> +     mem = devm_platform_ioremap_resource(pdev, 0);
> +     if (IS_ERR(mem))
> +             return PTR_ERR(mem);
> +
> +     pdata = devm_kzalloc(dev, sizeof(struct b53_platform_data),
> +                          GFP_KERNEL);
> +     if (!pdata)
> +             return -ENOMEM;
> +
> +     pdata->regs = mem;
> +     pdata->chip_id = BCM63XX_DEVICE_ID;
> +     pdata->big_endian = of_property_read_bool(np, "big-endian");
> +
> +     of_ports = of_get_child_by_name(np, "ports");

Isn't this leaking a ref on of_ports? I don't see any put.

> +     if (!of_ports) {
> +             dev_err(dev, "no ports child node found\n");
> +             return -EINVAL;
> +     }
> +
> +     for_each_available_child_of_node(of_ports, of_port) {
> +             u32 reg;
> +
> +             if (of_property_read_u32(of_port, "reg", &reg))
> +                     continue;
> +
> +             if (reg < B53_CPU_PORT)
> +                     pdata->enabled_ports |= BIT(reg);
> +     }
> +
> +     *ppdata = pdata;
> +
> +     return 0;
> +}
> +
>  static int b53_mmap_probe(struct platform_device *pdev)
>  {
> +     struct device_node *np = pdev->dev.of_node;
>       struct b53_platform_data *pdata = pdev->dev.platform_data;
>       struct b53_mmap_priv *priv;
>       struct b53_device *dev;
> +     int ret;
> +
> +     if (!pdata && np) {
> +             ret = b53_mmap_probe_of(pdev, &pdata);
> +             if (ret) {
> +                     dev_err(&pdev->dev, "OF probe error\n");
> +                     return ret;
> +             }
> +     }
>  
>       if (!pdata)
>               return -EINVAL;