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authorPaul Sokolovsky <pmiscml@gmail.com>2006-08-27 12:54:56 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2006-08-27 12:54:56 +0100
commit8f1bf8743c459399685f5df43021acd156548c22 (patch)
tree3eab5454e3dd04765f0f8b8d9f490596260d0ec5 /arch/arm/mach-sa1100/ssp.c
parentb53a2b41f156a9c9b62c14502037cbc15bc08b54 (diff)
[ARM] 3760/1: This patch adds timeouts while working with SSP registers. Such timeouts were en
Patch from Paul Sokolovsky This patch adds timeouts while working with SSP registers. Such timeouts were envisioned by docstrings in ssp.c, but were not implemented. There were actual lockups while accessing touchscreen for iPaqs h1910, h4000 due to lack of the timeouts. This is updated version of previously submitted patch: 3738/1. Signed-off-by: Paul Sokolovsky <pmiscml@gmail.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mach-sa1100/ssp.c')
-rw-r--r--arch/arm/mach-sa1100/ssp.c46
1 files changed, 38 insertions, 8 deletions
diff --git a/arch/arm/mach-sa1100/ssp.c b/arch/arm/mach-sa1100/ssp.c
index 1604dadf27fc..5eba5fbbb561 100644
--- a/arch/arm/mach-sa1100/ssp.c
+++ b/arch/arm/mach-sa1100/ssp.c
@@ -23,6 +23,8 @@
#include <asm/hardware.h>
#include <asm/hardware/ssp.h>
+#define TIMEOUT 100000
+
static irqreturn_t ssp_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
unsigned int status = Ser4SSSR;
@@ -47,18 +49,27 @@ static irqreturn_t ssp_interrupt(int irq, void *dev_id, struct pt_regs *regs)
* The caller is expected to perform the necessary locking.
*
* Returns:
- * %-ETIMEDOUT timeout occurred (for future)
+ * %-ETIMEDOUT timeout occurred
* 0 success
*/
int ssp_write_word(u16 data)
{
- while (!(Ser4SSSR & SSSR_TNF))
+ int timeout = TIMEOUT;
+
+ while (!(Ser4SSSR & SSSR_TNF)) {
+ if (!--timeout)
+ return -ETIMEDOUT;
cpu_relax();
+ }
Ser4SSDR = data;
- while (!(Ser4SSSR & SSSR_BSY))
+ timeout = TIMEOUT;
+ while (!(Ser4SSSR & SSSR_BSY)) {
+ if (!--timeout)
+ return -ETIMEDOUT;
cpu_relax();
+ }
return 0;
}
@@ -75,15 +86,22 @@ int ssp_write_word(u16 data)
* The caller is expected to perform the necessary locking.
*
* Returns:
- * %-ETIMEDOUT timeout occurred (for future)
+ * %-ETIMEDOUT timeout occurred
* 16-bit data success
*/
-int ssp_read_word(void)
+int ssp_read_word(u16 *data)
{
- while (!(Ser4SSSR & SSSR_RNE))
+ int timeout = TIMEOUT;
+
+ while (!(Ser4SSSR & SSSR_RNE)) {
+ if (!--timeout)
+ return -ETIMEDOUT;
cpu_relax();
+ }
+
+ *data = (u16)Ser4SSDR;
- return Ser4SSDR;
+ return 0;
}
/**
@@ -93,14 +111,26 @@ int ssp_read_word(void)
* is empty.
*
* The caller is expected to perform the necessary locking.
+ *
+ * Returns:
+ * %-ETIMEDOUT timeout occurred
+ * 0 success
*/
-void ssp_flush(void)
+int ssp_flush(void)
{
+ int timeout = TIMEOUT * 2;
+
do {
while (Ser4SSSR & SSSR_RNE) {
+ if (!--timeout)
+ return -ETIMEDOUT;
(void) Ser4SSDR;
}
+ if (!--timeout)
+ return -ETIMEDOUT;
} while (Ser4SSSR & SSSR_BSY);
+
+ return 0;
}
/**