Platform_device structure with more than one driver

AustinMarton · 01-19-2009, 10:36 PM

Hi there, I am working on two drivers for a network device running on uClinux. One is a char driver which controls the configuration registers, and one is a network driver which is responsible for tx/rx of Ethernet frames.

Since the base address and irq configuration could change, we have decided to register them both as a "platform_device".

I have managed to do this successfully with the network driver, but now it comes to doing the same with the character driver I am not sure how to go about it.

Can anyone link me to some sort of outline of the platform device structure? Although it is mentioned a lot I am having difficulty finding any actual definition of how to use it. Does anyone know how this works with two drivers accessing the same resource? Do I need to create two resources with the same address?

Currently my setup.c file looks something like this...

Code:

#if defined(CONFIG_mydriv) && defined(na_mydriv)
#include <linux/mydriv.h>
static struct resource mydriv_resource[] = {
	[0] = {	/* Address */
		.start = na_mydriv + 0,	/* 70 */
		.end   = na_mydriv + 3,	/* 73 */
		.flags = IORESOURCE_MEM,
	},
	[1] = { /* Data */
		.start = na_mydriv + 4,	/* 74 */
		.end   = na_mydriv + 5,	/* 75 */
		.flags = IORESOURCE_MEM,
	},
	[2] = { /* IRQ */
		.start = na_mydriv_irq,	/* 4 */
		.end   = na_mydriv_irq, 	/* 4 */
		.flags = IORESOURCE_IRQ | IRQF_TRIGGER_FALLING,
	},
	[3] = { /* CPU_FRAME_REG */
		.start = na_mydriv + 6,	/* 76 */
		.end   = na_mydriv + 7, 	/* 77 */
		.flags = IORESOURCE_MEM,
	},
	[4] = { /* CMD_STATUS_REG */
		.start = na_mydriv + 8,	/* 78 */
		.end   = na_mydriv + 9, 	/* 79 */
		.flags = IORESOURCE_MEM,
	},
	[5] = { /* INT_REG */
		.start = na_mydriv + 10,	/* 7A */
		.end   = na_mydriv + 11, 	/* 7B */
		.flags = IORESOURCE_MEM,
	},
	[6] = { /* CTL_FRAME_BUF1 */
		.start = na_mydriv + 12,	/* 7C */
		.end   = na_mydriv + 13, 	/* 7D */
		.flags = IORESOURCE_MEM,
	},
	[7] = { /* CTL_FRAME_BUF2 */
		.start = na_mydriv + 14,	/* 7E */
		.end   = na_mydriv + 15, 	/* 7F */
		.flags = IORESOURCE_MEM,
	}

};
static struct mydriv_plat_data mydriv_platdata = {
	.flags		= mydriv_PLATF_16BITONLY,
};
static struct platform_device mydriv_device = {
	.name		= "mydriv",
	.id		= 0,
	.num_resources	= ARRAY_SIZE(mydriv_resource),
	.resource	= mydriv_resource,
	.dev		= {
		.platform_data = &mydriv_platdata,
	}
};
static int __init mydriv_device_init(void)
{
	/* customizes platform devices, or adds new ones */
	platform_device_register(&mydriv_device);
	return 0;
}
arch_initcall(mydriv_device_init);
#endif