Re: [RFC PATCH] debugfs: add tools to printk 32-bit registers

From: Felipe Balbi
Date: Tue Nov 15 2011 - 17:04:43 EST


Hi,

On Tue, Nov 15, 2011 at 10:37:34PM +0100, Alessandro Rubini wrote:
> Hi Greg. Thanks for looking.
>
> >> +/*
> >> + * The regset32 stuff is used to print 32-bit registers using the
> >> + * seq_file utilities. We offer printing a register set in an already-opened
> >> + * sequential file or create a debugfs file that only prints a regset32.
> >> + */
> >
> > Can this be part of the kerneldoc below somehow so that people are more
> > aware of it?
>
> Ok. There's also a file by Jon in Documentation that needs updating, as it
> has all the other debugfs file types.
>
> > +int debugfs_print_regs32(struct seq_file *s, struct debugfs_reg32 *regs,
> >> + int nregs, void __iomem *base, char *prefix)
>
> > This function also needs to be part of debugfs.h in the "debugfs is not
> > enabled" section of the file, right?
>
> Not really. The other one makes a regiters-only file, and it's good
> to register it withouth ifdef.
>
> This one is used to embed a register block in a file with more
> stuff, so it shouldn't be used if debugfs is not selected (btw,
> I compiled my internal stuff with and without CONFIG_DEBUG_FS
> before rebasing to next).
>
> Example:
>
> static int pl08x_debugfs_show(struct seq_file *s, void *data)
> {
> [...]
> list_for_each_entry(chan, &pl08x->slave.channels, chan.device_node) {
> seq_printf(s, "%s\t\t%s\n", chan->name,
> pl08x_state_str(chan->state));
> }
>
> /* dump registers */
> seq_printf(s, "\nPL08x registers\n");
> debugfs_print_regs32(s, pl08x_regs, ARRAY_SIZE(pl08x_regs),
> pl08x->base, "");
>
> seq_printf(s, "\nPL08x registers channel\n");
> for (i = 0; i < pl08x->vd->channels; i++) {
> [...]
> }
>
> So, I'll post a V2 shortly, unless you refuse it in reply to this.

this will be useful to dwc3 too, we currently have:

struct dwc3_register {
const char *name;
u32 offset;
};

#define dump_register(nm) \
{ \
.name = __stringify(nm), \
.offset = DWC3_ ##nm, \
}

static const struct dwc3_register dwc3_regs[] = {
dump_register(GSBUSCFG0),
dump_register(GSBUSCFG1),
dump_register(GTXTHRCFG),

...
};

static int dwc3_regdump_show(struct seq_file *s, void *unused)
{
struct dwc3 *dwc = s->private;
int i;

seq_printf(s, "DesignWare USB3 Core Register Dump\n");

for (i = 0; i < ARRAY_SIZE(dwc3_regs); i++) {
seq_printf(s, "%-20s : %08x\n", dwc3_regs[i].name,
dwc3_readl(dwc->regs, dwc3_regs[i].offset));
}

return 0;
}

...

--
balbi

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