Kernel oops while power off, custom mx28 board.

[Andrzej]

Dear Community,

I'm trying to shut down i.MX28 custom board using kernel 3.18.22.

Code added to arch/arm/mach-mxs/pm.c as follows:

#define REGS_POWER_BASE 0x80044000

#define POWER_RESET_UNLOCK_KEY (0x3e77 << 16)

#define MX28_HW_POWER_RESET 0x100

#define MX28_HW_POWER_RESET_SET 0x104

(...)

static void customMX28_pm_power_off(void)

{

     writel(POWER_RESET_UNLOCK_KEY,  REGS_POWER_BASE + MX28_HW_POWER_RESET_SET );

     writel(POWER_RESET_UNLOCK_KEY | POWER_RESET_PWD_OFF, REGS_POWER_BASE + MX28_HW_POWER_RESET_SET );

}

(...)

void __init mxs_pm_init(void)

{

        pm_power_off = customMX28_pm_power_off;

        suspend_set_ops(&mxs_suspend_ops);

}

When I tried to poweroff device, kernel Oops message appears:

Unable to handle kernel paging request at virtual address 80044104

What am I doing wrong?
Regards

Andrzej

[igorpadykov]

Hi Andrzej

in general it should work, however had this register IO mapped smth like

#define MX6Q_IO_ADDRESS(x)

IOMEM(MX6Q_IO_P2V(x))

Best regards

igor

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[Andrzej]

Hi Igor,
thanks for your hint. I've modified source code as below

#define IMX_IO_P2V(x)   (	\
	(((x) & 0x80000000) >> 7) |	\
	(0xf4000000 +	\
	(((x) & 0x50000000) >> 6) +	\
	(((x) & 0x0b000000) >> 4) +	\
	(((x) & 0x000fffff))))

#define IMX_IO_ADDRESS(x)  IOMEM(IMX_IO_P2V(x))

#define REGS_POWER_BASE_PADDR 0x80044000

#define REGS_POWER_BASE_VADDR  IMX_IO_ADDRESS(REGS_POWER_BASE_PADDR))

#define POWER_RESET_SET (REGS_POWER_BASE_VADDR + MX28_HW_POWER_RESET_SET)

and then I call

writel(POWER_RESET_UNLOCK_KEY, POWER_RESET_SET );

but unfortunately I've got very similar kernel oops as at begin, this time pointing to proper virtual address:

Unable to handle kernel paging request at virtual address f5044104

pgd = c7a38000

[f5044104] *pgd=00000000

Internal error: Oops - BUG: 805 [#1] PREEMPT ARM

[lategoodbye]

Hi Andrzej,

better use the devicetree to get the virtual address:

np = of_find_compatible_node(NULL, NULL, "fsl,imx28-power");

of_address_to_resource(np, 0, &res);

paddr = ioremap(res.start, resource_size(&res));

Regards Stefan