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Commit 5443856c authored by Sascha Hauer's avatar Sascha Hauer
Browse files

i.MX51: determine silicon revision dynamically 



Freescale redboot passes the silicon revision via
ATAG_REVISION. Remove this bootloader dependency by
doing the same as redboot does in the Kernel.

Signed-off-by: default avatarSascha Hauer <s.hauer@pengutronix.de>
parent 3d1bc862

arch/arm/mach-mx5/cpu.c

+53 −0
Original line number Diff line number Diff line
@@ -14,9 +14,62 @@ 
#include <linux/types.h>

#include <linux/kernel.h>

#include <linux/init.h>

#include <linux/module.h>

#include <mach/hardware.h>

#include <asm/io.h>



static int cpu_silicon_rev = -1;



#define SI_REV 0x48



static void query_silicon_parameter(void)

{

	void __iomem *rom = ioremap(MX51_IROM_BASE_ADDR, MX51_IROM_SIZE);

	u32 rev;



	if (!rom) {

		cpu_silicon_rev = -EINVAL;

		return;

	}



	rev = readl(rom + SI_REV);

	switch (rev) {

	case 0x1:

		cpu_silicon_rev = MX51_CHIP_REV_1_0;

		break;

	case 0x2:

		cpu_silicon_rev = MX51_CHIP_REV_1_1;

		break;

	case 0x10:

		cpu_silicon_rev = MX51_CHIP_REV_2_0;

		break;

	case 0x20:

		cpu_silicon_rev = MX51_CHIP_REV_3_0;

		break;

	default:

		cpu_silicon_rev = 0;

	}



	iounmap(rom);

}



/*

 * Returns:

 *	the silicon revision of the cpu

 *	-EINVAL - not a mx51

 */

int mx51_revision(void)

{

	if (!cpu_is_mx51())

		return -EINVAL;



	if (cpu_silicon_rev == -1)

		query_silicon_parameter();



	return cpu_silicon_rev;

}

EXPORT_SYMBOL(mx51_revision);



static int __init post_cpu_init(void)

{

	unsigned int reg;

arch/arm/plat-mxc/include/mach/mx51.h

+7 −6
Original line number Diff line number Diff line
@@ -27,6 +27,12 @@ 
 *

 */



/*

 * IROM

 */

#define MX51_IROM_BASE_ADDR		0x0

#define MX51_IROM_SIZE			SZ_64K



/*

 * IRAM

 */
@@ -438,12 +444,7 @@ 


#if !defined(__ASSEMBLY__) && !defined(__MXC_BOOT_UNCOMPRESS)



extern unsigned int system_rev;



static inline unsigned int mx51_revision(void)

{

	return system_rev;

}

extern int mx51_revision(void);

#endif



#endif	/*  __ASM_ARCH_MXC_MX51_H__ */