[PATCH] omap: mux: fix multipath gpio handling

[PATCH] omap: mux: fix multipath gpio handling

[Grazvydas Ignotas]

OMAP3530 CBB package can have GPIO126 muxed on 2 pins: mmc1_dat4 and
cam_strobe. This causes a problem with current multipath GPIO mux
handling, which muxes both pins as GPIO126 and makes the GPIO unusable.

Fix this by not muxing any pins if multipath GPIO is detected and
just print a warning instead. It's up to board files to set correct
mux using omap_mux_init_signal and pin name.

Signed-off-by: Grazvydas Ignotas <notasas@gmail.com>
---
 arch/arm/mach-omap2/mux.c |   38 ++++++++++++++++++++------------------
 1 files changed, 20 insertions(+), 18 deletions(-)

diff --git a/arch/arm/mach-omap2/mux.c b/arch/arm/mach-omap2/mux.c
index be52fab..ab403b2 100644
--- a/arch/arm/mach-omap2/mux.c
+++ b/arch/arm/mach-omap2/mux.c
@@ -87,6 +87,9 @@ static char *omap_mux_options;
 int __init omap_mux_init_gpio(int gpio, int val)
 {
 	struct omap_mux_entry *e;
+	struct omap_mux *gpio_mux;
+	u16 old_mode;
+	u16 mux_mode;
 	int found = 0;
 
 	if (!gpio)
@@ -95,34 +98,33 @@ int __init omap_mux_init_gpio(int gpio, int val)
 	list_for_each_entry(e, &muxmodes, node) {
 		struct omap_mux *m = &e->mux;
 		if (gpio == m->gpio) {
-			u16 old_mode;
-			u16 mux_mode;
-
-			old_mode = omap_mux_read(m->reg_offset);
-			mux_mode = val & ~(OMAP_MUX_NR_MODES - 1);
-			if (omap_mux_flags & MUXABLE_GPIO_MODE3)
-				mux_mode |= OMAP_MUX_MODE3;
-			else
-				mux_mode |= OMAP_MUX_MODE4;
-			printk(KERN_DEBUG "mux: Setting signal "
-				"%s.gpio%i 0x%04x -> 0x%04x\n",
-				m->muxnames[0], gpio, old_mode, mux_mode);
-			omap_mux_write(mux_mode, m->reg_offset);
+			gpio_mux = m;
 			found++;
 		}
 	}
 
-	if (found == 1)
-		return 0;
+	if (found == 0) {
+		printk(KERN_ERR "mux: Could not set gpio%i\n", gpio);
+		return -ENODEV;
+	}
 
 	if (found > 1) {
-		printk(KERN_ERR "mux: Multiple gpio paths for gpio%i\n", gpio);
+		printk(KERN_INFO "mux: Multiple gpio paths (%d) for gpio%i\n",
+				found, gpio);
 		return -EINVAL;
 	}
 
-	printk(KERN_ERR "mux: Could not set gpio%i\n", gpio);
+	old_mode = omap_mux_read(gpio_mux->reg_offset);
+	mux_mode = val & ~(OMAP_MUX_NR_MODES - 1);
+	if (omap_mux_flags & MUXABLE_GPIO_MODE3)
+		mux_mode |= OMAP_MUX_MODE3;
+	else
+		mux_mode |= OMAP_MUX_MODE4;
+	printk(KERN_DEBUG "mux: Setting signal %s.gpio%i 0x%04x -> 0x%04x\n",
+			gpio_mux->muxnames[0], gpio, old_mode, mux_mode);
+	omap_mux_write(mux_mode, gpio_mux->reg_offset);
 
-	return -ENODEV;
+	return 0;
 }
 
 int __init omap_mux_init_signal(char *muxname, int val)
-- 
1.5.6.3

Re: [PATCH] omap: mux: fix multipath gpio handling

[Tony Lindgren]

* Grazvydas Ignotas <notasas@gmail.com> [100705 23:00]:
> OMAP3530 CBB package can have GPIO126 muxed on 2 pins: mmc1_dat4 and
> cam_strobe. This causes a problem with current multipath GPIO mux
> handling, which muxes both pins as GPIO126 and makes the GPIO unusable.
> 
> Fix this by not muxing any pins if multipath GPIO is detected and
> just print a warning instead. It's up to board files to set correct
> mux using omap_mux_init_signal and pin name.

This looks good to me. Are you OK if we merge it during the upcoming
merge window? Kind of worried that we might break some other boards
that rely on the first GPIO getting muxed..

Tony

Re: [PATCH] omap: mux: fix multipath gpio handling

[Grazvydas Ignotas]

On Tue, Jul 6, 2010 at 4:25 PM, Tony Lindgren <tony@atomide.com> wrote:
> * Grazvydas Ignotas <notasas@gmail.com> [100705 23:00]:
>> OMAP3530 CBB package can have GPIO126 muxed on 2 pins: mmc1_dat4 and
>> cam_strobe. This causes a problem with current multipath GPIO mux
>> handling, which muxes both pins as GPIO126 and makes the GPIO unusable.
>>
>> Fix this by not muxing any pins if multipath GPIO is detected and
>> just print a warning instead. It's up to board files to set correct
>> mux using omap_mux_init_signal and pin name.
>
> This looks good to me. Are you OK if we merge it during the upcoming
> merge window? Kind of worried that we might break some other boards
> that rely on the first GPIO getting muxed..

Yeah that should be fine, no need to rush.

[APPLIED] [PATCH] omap: mux: fix multipath gpio handling

[Tony Lindgren]

This patch has been applied to the linux-omap
by youw fwiendly patch wobot.

Branch in linux-omap: for-next

Initial commit ID (Likely to change): 916c48fbec05b4718b4fd447f634725ced6cc9e7

PatchWorks
http://patchwork.kernel.org/patch/110284/

Git (Likely to change, and takes a while to get mirrored)
http://git.kernel.org/?p=linux/kernel/git/tmlind/linux-omap-2.6.git;a=commit;h=916c48fbec05b4718b4fd447f634725ced6cc9e7