arch/arm/mach-omap2/id.c

Source file repositories/reference/linux-study-clean/arch/arm/mach-omap2/id.c

File Facts

System
Linux kernel
Corpus path
arch/arm/mach-omap2/id.c
Extension
.c
Size
18590 bytes
Lines
812
Domain
Architecture Layer
Bucket
arch/arm
Inferred role
Architecture Layer: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

struct omap_id {
	u16	hawkeye;	/* Silicon type (Hawkeye id) */
	u8	dev;		/* Device type from production_id reg */
	u32	type;		/* Combined type id copied to omap_revision */
};

/* Register values to detect the OMAP version */
static struct omap_id omap_ids[] __initdata = {
	{ .hawkeye = 0xb5d9, .dev = 0x0, .type = 0x24200024 },
	{ .hawkeye = 0xb5d9, .dev = 0x1, .type = 0x24201024 },
	{ .hawkeye = 0xb5d9, .dev = 0x2, .type = 0x24202024 },
	{ .hawkeye = 0xb5d9, .dev = 0x4, .type = 0x24220024 },
	{ .hawkeye = 0xb5d9, .dev = 0x8, .type = 0x24230024 },
	{ .hawkeye = 0xb68a, .dev = 0x0, .type = 0x24300024 },
};

static void __iomem *tap_base;
static u16 tap_prod_id;

static void omap_get_die_id(struct omap_die_id *odi)
{
	if (soc_is_omap44xx() || soc_is_omap54xx() || soc_is_dra7xx()) {
		odi->id_0 = read_tap_reg(OMAP_TAP_DIE_ID_44XX_0);
		odi->id_1 = read_tap_reg(OMAP_TAP_DIE_ID_44XX_1);
		odi->id_2 = read_tap_reg(OMAP_TAP_DIE_ID_44XX_2);
		odi->id_3 = read_tap_reg(OMAP_TAP_DIE_ID_44XX_3);

		return;
	}
	odi->id_0 = read_tap_reg(OMAP_TAP_DIE_ID_0);
	odi->id_1 = read_tap_reg(OMAP_TAP_DIE_ID_1);
	odi->id_2 = read_tap_reg(OMAP_TAP_DIE_ID_2);
	odi->id_3 = read_tap_reg(OMAP_TAP_DIE_ID_3);
}

static int __init omap_feed_randpool(void)
{
	struct omap_die_id odi;

	/* Throw the die ID into the entropy pool at boot */
	omap_get_die_id(&odi);
	add_device_randomness(&odi, sizeof(odi));
	return 0;
}
omap_device_initcall(omap_feed_randpool);

void __init omap2xxx_check_revision(void)
{
	int i, j;
	u32 idcode, prod_id;
	u16 hawkeye;
	u8  dev_type, rev;
	struct omap_die_id odi;

	idcode = read_tap_reg(OMAP_TAP_IDCODE);
	prod_id = read_tap_reg(tap_prod_id);
	hawkeye = (idcode >> 12) & 0xffff;
	rev = (idcode >> 28) & 0x0f;
	dev_type = (prod_id >> 16) & 0x0f;
	omap_get_die_id(&odi);

	pr_debug("OMAP_TAP_IDCODE 0x%08x REV %i HAWKEYE 0x%04x MANF %03x\n",
		 idcode, rev, hawkeye, (idcode >> 1) & 0x7ff);
	pr_debug("OMAP_TAP_DIE_ID_0: 0x%08x\n", odi.id_0);
	pr_debug("OMAP_TAP_DIE_ID_1: 0x%08x DEV_REV: %i\n",
		 odi.id_1, (odi.id_1 >> 28) & 0xf);
	pr_debug("OMAP_TAP_DIE_ID_2: 0x%08x\n", odi.id_2);
	pr_debug("OMAP_TAP_DIE_ID_3: 0x%08x\n", odi.id_3);
	pr_debug("OMAP_TAP_PROD_ID_0: 0x%08x DEV_TYPE: %i\n",
		 prod_id, dev_type);

	/* Check hawkeye ids */
	for (i = 0; i < ARRAY_SIZE(omap_ids); i++) {
		if (hawkeye == omap_ids[i].hawkeye)
			break;
	}

	if (i == ARRAY_SIZE(omap_ids)) {
		printk(KERN_ERR "Unknown OMAP CPU id\n");
		return;
	}

	for (j = i; j < ARRAY_SIZE(omap_ids); j++) {
		if (dev_type == omap_ids[j].dev)
			break;
	}

	if (j == ARRAY_SIZE(omap_ids)) {
		pr_err("Unknown OMAP device type. Handling it as OMAP%04x\n",
		       omap_ids[i].type >> 16);

Annotation

Implementation Notes