Driver linux : pass platform_data through struct resource

Question

I have a problem writing a device driver. The number of fields in the platform_data struct is getting too big because of the different use cases. I already have 14 fields and I have to add at least 5 others. The code is getting unreadable.

My manager insists that I use a "struct resource" to pass the parameters. But I can't find an tutorial or at least an example to show me how to do that.

Can you help me to do this?

Answer 1

I'd agree that the kernel documentation for platform devices doesn't quite explain everything, hope this helps.

In the board file:

static struct resource mydevice_resource[] = {
    [0] = {
        .start  = MYDEVICE_REG_START,
        .end    = MYDEVICE_REG_STOP,
        .flags = IORESOURCE_MEM,
    },
    [1] = {
        .start = MYDEVICE_IV,
        .end   = MYDEVICE_IV,
        .flags = IORESOURCE_IRQ,
    },
};

...

static struct platform_device mydevice_device = {
    .name = "mydevice",
    .id = MYDEVICE_ID_1,
    .num_resources = ARRAY_SIZE(mydevice_resource),
    .resource = mydevice_resource,
    .dev = {
            /* .platform_data = ... if needed */
    },
};

In the driver:

static int __devinit mydevice_probe(struct platform_device *pdev)
{
        struct resource *res;

        ...

        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        if (!res)
                return -ENODEV;

        ...