Kernel module for configuration pin

Slava Muzychko

Hi,

I generated the files mux.h and pinmux.h using Pin Mux Utility for am335x.

I use VAR-SOM-AM33.

I try write kernel module for configuration pin using generated header files.

In header mux.h i changed call function writel(VALUE,AM335X_CTRL_BASE+OFFSET) to my function write_data(OFFSET,VALUE).

my write_data function :

static void write_data(u32 off,u32 val)
{
    iowrite32(val,virt_addr + off);
}

my init function :

#define AM335X_CTRL_BASE 0x44E10000

static u32* virt_addr;

static int __init mod_init(void)
{
    if(!request_mem_region(AM335X_CTRL_BASE,0x0B35,"conf pin")) printk(KERN_WARNING "%s: can not get region\n",MODNAME);
    
    virt_addr = (u32*)ioremap(AM335X_CTRL_BASE,0x0B35);
   
    if(!virt_addr) printk(KERN_WARNING "%s: can not get virtual address\n",MODNAME);

    MUX_EVM();

    return 0;
}

Module works when i call MUX_VAL once.However when i call all definitions MUX_VAL system freezes.
Is it possible to write such module,and how?

over 11 years ago

0 Biser Gatchev-XID over 11 years ago

TI__Guru**** 393215 points

Hi Slava,

Could you post again? The post formatting is garbled and we can't see everything.

0 Miroslav Kiradzhiyski XID over 11 years ago

TI__Mastermind 25235 points

Hi Slava,

Check the omap_mux_init_signal() function inside <linux_dir>/arch/arm/mach-omap2/mux.c:

int __init omap_mux_init_signal(const char *muxname, int val)
{
	struct omap_mux_partition *partition = NULL;
	struct omap_mux *mux = NULL;
	u16 old_mode;
	int mux_mode;

	mux_mode = omap_mux_get_by_name(muxname, &partition, &mux);
	if (mux_mode < 0)
		return mux_mode;

	old_mode = omap_mux_read(partition, mux->reg_offset);
	mux_mode |= val;
	pr_debug("%s: Setting signal %s 0x%04x -> 0x%04x\n",
			 __func__, muxname, old_mode, mux_mode);
	omap_mux_write(partition, mux_mode, mux->reg_offset);

	return 0;
}

Best regards,
Miroslav

0 Slava Muzychko over 11 years ago in reply to Miroslav Kiradzhiyski XID

Prodigy 60 points

data is written,but then system crash

console show :

[ 497.241149] UBI error: ubi_io_read: error -74 (ECC error) while reading 2530 bytes from PEB 662:128360, read 2530 bytes
[ 497.252471] UBIFS error (pid 1431): ubifs_leb_read: reading 2530 bytes from LEB 660:124264 failed, error -74
[ 497.262725] UBIFS error (pid 1431): try_read_node: cannot read node type 1 from LEB 660:124264, error -74
[ 497.277740] UBI error: ubi_io_read: error -74 (ECC error) while reading 2530 bytes from PEB 662:128360, read 2530 bytes
[ 497.289031] UBIFS error (pid 1431): ubifs_read_node: bad node type (0 but expected 1)
[ 497.297210] UBIFS error (pid 1431): ubifs_read_node: bad node at LEB 660:124264, LEB mapping status 1
[ 497.306854] UBIFS error (pid 1431): do_readpage: cannot read page 13 of inode 6155, error -22

0 Miroslav Kiradzhiyski XID over 11 years ago in reply to Slava Muzychko

TI__Mastermind 25235 points

Slava, these are UBIFS errors. Please read this post, where I have explained the details regarding the UBIFS creation: http://e2e.ti.com/support/arm/sitara_arm/f/791/p/268305/941327.aspx#941327

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Kernel module for configuration pin