Felipe Balbi had written, on 10/23/2009 05:56 PM, the following:
On Fri, Oct 23, 2009 at 09:25:29PM +0530, charu@xxxxxx wrote:
From: Charulatha V <charu@xxxxxx>
During initialization, GPIO module is reset using soft reset bit
of SYSCONFIG register
Signed-off-by: Charulatha V <charu@xxxxxx>
---
arch/arm/plat-omap/gpio.c | 12 +++++++++++-
1 files changed, 11 insertions(+), 1 deletions(-)
diff --git a/arch/arm/plat-omap/gpio.c b/arch/arm/plat-omap/gpio.c
index 2304a5d..4579650 100644
--- a/arch/arm/plat-omap/gpio.c
+++ b/arch/arm/plat-omap/gpio.c
@@ -21,6 +21,7 @@
#include <linux/err.h>
#include <linux/clk.h>
#include <linux/io.h>
+#include <linux/delay.h>
#include <mach/hardware.h>
#include <asm/irq.h>
@@ -1670,7 +1671,7 @@ static int __init _omap_gpio_init(void)
}
#endif
for (i = 0; i < gpio_bank_count; i++) {
- int j, gpio_count = 16;
+ int j, gpio_count = 16, attempt = 0;
decrementing is better, so:
attempt = 1000
please move attempt out of here to the {} for 3430.. Warning for OMAP1.
bank = &gpio_bank[i];
spin_lock_init(&bank->lock);
@@ -1698,6 +1699,15 @@ static int __init _omap_gpio_init(void)
static const u32 non_wakeup_gpios[] = {
0xe203ffc0, 0x08700040
};
+
+ /* Software Reset of GPIO module */
+ __raw_writel(0x0002, bank->base + OMAP24XX_GPIO_SYSCONFIG);
+ while (((__raw_readl(bank->base + OMAP24XX_GPIO_SYSSTATUS)
+ & 0x1) == 0) && attempt < 5) {
&& attemp)
+ udelay(1);
i guess cpu_relax() is better here.
+ attempt++;
attempt--;
cant we improve this code as following:
{
u8 attempts = 25;
/* Software Reset of GPIO module */
__raw_writel(0x0002, bank->base
+ OMAP24XX_GPIO_SYSCONFIG);
/* wait for reset to be done */
while (((__raw_readl(bank->base +
OMAP24XX_GPIO_SYSSTATUS) & 0x1) == 0)
&& attempts) {
cpu_relax();
if (attempts % 5)
udelay(1);
attempts--;
}
allows the kernel to do somethin else while we also ensure we have a 5
usec guarenteed delay before giving up..
--
Regards,
Nishanth Menon
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