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authorIgor Grinberg <grinberg@compulab.co.il>2012-04-12 14:43:29 +0200
committerHaojian Zhuang <haojian.zhuang@gmail.com>2012-04-27 05:14:06 +0200
commitef7c7c693b4b05a293678fd40ed1511bc94d6f61 (patch)
tree9ea5270c9139d9dd1047738c5eda6d89ef311162 /arch/arm/mach-pxa/mfp-pxa2xx.c
parentARM: PXA2xx: MFP: fix bug with MFP_LPM_KEEP_OUTPUT (diff)
downloadlinux-ef7c7c693b4b05a293678fd40ed1511bc94d6f61.tar.xz
linux-ef7c7c693b4b05a293678fd40ed1511bc94d6f61.zip
ARM: PXA2xx: MFP: fix potential direction bug
Pins configured as input and have MFP_LPM_DRIVE_* flag set, can have a wrong output value for some period of time (spike) during the suspend sequence. This can happen because the direction of the pins (GPDR) is set by software and the output level is set by hardware (PGSR) at a later stage. Fix the above potential bug by setting the output levels first. Also save the actual levels of the pins before the suspend and restore them after the resume, but before the direction settings take place, so the same bug as described above will not happen in the resume sequence. Reported-by: Paul Parsons <lost.distance@yahoo.com> Signed-off-by: Igor Grinberg <grinberg@compulab.co.il> Tested-by: Paul Parsons <lost.distance@yahoo.com> Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Diffstat (limited to '')
-rw-r--r--arch/arm/mach-pxa/mfp-pxa2xx.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/arm/mach-pxa/mfp-pxa2xx.c b/arch/arm/mach-pxa/mfp-pxa2xx.c
index d2373d79b657..ef0426a159d4 100644
--- a/arch/arm/mach-pxa/mfp-pxa2xx.c
+++ b/arch/arm/mach-pxa/mfp-pxa2xx.c
@@ -33,6 +33,8 @@
#define BANK_OFF(n) (((n) < 3) ? (n) << 2 : 0x100 + (((n) - 3) << 2))
#define GPLR(x) __REG2(0x40E00000, BANK_OFF((x) >> 5))
#define GPDR(x) __REG2(0x40E00000, BANK_OFF((x) >> 5) + 0x0c)
+#define GPSR(x) __REG2(0x40E00000, BANK_OFF((x) >> 5) + 0x18)
+#define GPCR(x) __REG2(0x40E00000, BANK_OFF((x) >> 5) + 0x24)
#define PWER_WE35 (1 << 24)
@@ -348,6 +350,7 @@ static inline void pxa27x_mfp_init(void) {}
#ifdef CONFIG_PM
static unsigned long saved_gafr[2][4];
static unsigned long saved_gpdr[4];
+static unsigned long saved_gplr[4];
static unsigned long saved_pgsr[4];
static int pxa2xx_mfp_suspend(void)
@@ -369,7 +372,11 @@ static int pxa2xx_mfp_suspend(void)
saved_gafr[0][i] = GAFR_L(i);
saved_gafr[1][i] = GAFR_U(i);
saved_gpdr[i] = GPDR(i * 32);
+ saved_gplr[i] = GPLR(i * 32);
saved_pgsr[i] = PGSR(i);
+
+ GPSR(i * 32) = PGSR(i);
+ GPCR(i * 32) = ~PGSR(i);
}
/* set GPDR bits taking into account MFP_LPM_KEEP_OUTPUT */
@@ -392,6 +399,8 @@ static void pxa2xx_mfp_resume(void)
for (i = 0; i <= gpio_to_bank(pxa_last_gpio); i++) {
GAFR_L(i) = saved_gafr[0][i];
GAFR_U(i) = saved_gafr[1][i];
+ GPSR(i * 32) = saved_gplr[i];
+ GPCR(i * 32) = ~saved_gplr[i];
GPDR(i * 32) = saved_gpdr[i];
PGSR(i) = saved_pgsr[i];
}