Re: replacement for /sys/kernel/debug/omap_mux in DT/pinctrl land ?

[Matt Porter <mporter@ti.com>]

On Wed, Sep 26, 2012 at 03:03:27PM +0200, Linus Walleij wrote:
> On Wed, Sep 26, 2012 at 2:56 PM, Matt Porter <mporter@ti.com> wrote:
> > Adding Linus W. and lkml.
> > On Wed, Sep 26, 2012 at 01:46:45PM +0200, Koen Kooi wrote:
> >> Hi,
> >>
> >> With a patched 3.6rc7 on my beaglebone I can set the pinmux for pins using pinctrl and that seems to work. On the 3.2 vendor tree there was the omap_mux driver with an awesome debugfs interface:
> >>
> >> # cat /sys/kernel/debug/omap_mux/lcd_data0
> >> name: lcd_data0.ehrpwm2A (0x44e108a0/0x8a0 = 0x0003), b NA, t NA
> >> mode: OMAP_PIN_OUTPUT | OMAP_MUX_MODE3
> >> signals: lcd_data0 | gpmc_a0 | pr1_mii_mt0_clk | ehrpwm2A | NA | pr1_pru1_pru_r30_0 | pr1_pru1_pru_r31_0 | gpio2_6
> >>
> >> Notice how it tells me that it's muxed the PWM in 2 ways: signal name (ehrpwm2A) and register content (0x0003). Compare to pinctrl:
> >>
> >> root@bone-mainline:/sys/kernel/debug/pinctrl/44e10800.pinmux# grep 8a0 *
> >> pinconf-pins:pin 40 (44e108a0):
> >> pingroups:pin 40 (44e108a0)
> >> pinmux-pins:pin 40 (44e108a0): 4a300000.pruss (GPIO UNCLAIMED) function pinmux_pruss_led_pins group pinmux_pruss_led_pins
> >> pins:pin 40 (44e108a0)  pinctrl-single
> >>
> >> What is that pin muxed to? It is part of the 'pinmux_pruss_led_pins' in the DT, but debugfs remains mute on how pin 40 is muxed.
> >
> > It does seem like a pretty big gap in the pinctrl/pinmux debugfs
> > interface when viewed from an OMAP perspective. Ideally there would
> > be a pinctrl/pinmux hook to the pinmux driver to provide the detailed
> > h/w specific pin state info.
> 
> So add the hooks you need?
 
Ok. :)

> I assume you are using Tony's pinctrl-single driver, so Tony is the one to ask.

Yes, so roughly for pinctrl-single I have the following...likely broken
for arbitrary register sizes but a starting point. Tony, any thoughts
about this?

Koen: you just need a userspace tool that groks the raw data for human
consumption. The nice thing is that the old omap_mux implementation had
plenty of OMAP-isms in the parser that didn't apply to AM33xx. A
userspace tool can do a better job of parsing on a per-part basis.

--- a/drivers/pinctrl/pinctrl-single.c
+++ b/drivers/pinctrl/pinctrl-single.c
@@ -246,7 +246,15 @@ static void pcs_pin_dbg_show(struct pinctrl_dev *pctldev,
 					struct seq_file *s,
 					unsigned offset)
 {
-	seq_printf(s, " " DRIVER_NAME);
+	struct pcs_device *pcs;
+	unsigned val;
+
+	pcs = pinctrl_dev_get_drvdata(pctldev);
+
+	val = pcs->read(pcs->base + offset);
+	val &= pcs->fmask;
+
+	seq_printf(s, "%08x %s " , val, DRIVER_NAME);
 }
 
 static void pcs_dt_free_map(struct pinctrl_dev *pctldev,