[ARM] pxa: enable GPIO receivers after configuring pins

'mach-pxa' platforms currently rely on a bootloader to setup GPIO pins
and clear RDH (to enable inputs).

A kernel loaded by a 'minimal' bootloader, that doesn't touch any pins,
will not function correctly; inputs will remain disabled, even after the
pins are configured. The following change fixes the issue and has been
verified on Gumstix Verdex XL6P and a custom PXA270 platform.

Signed-off-by: Timothy Clacy <tcl@phaseone.com>
Signed-off-by: Eric Miao <eric.miao@marvell.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/arm/mach-pxa/mfp-pxa2xx.c b/arch/arm/mach-pxa/mfp-pxa2xx.c
index 6ae50604170..cf6b720c055 100644
--- a/arch/arm/mach-pxa/mfp-pxa2xx.c
+++ b/arch/arm/mach-pxa/mfp-pxa2xx.c
@@ -377,6 +377,9 @@ static int __init pxa2xx_mfp_init(void)
         if (cpu_is_pxa27x())
                 pxa27x_mfp_init();
 
+        /* clear RDH bit to enable GPIO receivers after reset/sleep exit */
+        PSSR = PSSR_RDH;
+
         /* initialize gafr_run[], pgsr_lpm[] from existing values */
         for (i = 0; i <= gpio_to_bank(pxa_last_gpio); i++)
                 gpdr_lpm[i] = GPDR(i * 32);