In case some transactions to the Serial Power Controller (SPC) are lost owing
to multiple operations handled at once by the M3 controller the OS needs to
rely on a configuration API that can time out so that failures do not result
in an unusable system.
This patch adds a timeout API to the vexpress config programming interface,
and refactors the existing read/write functions so that they can be reused
seamlessly on top of the newly defined API.
Cc: Samuel Ortiz <sa...@linux.intel.com>
Cc: Achin Gupta <achin.gu...@arm.com>
Cc: Sudeep KarkadaNagesha <sudeep.karkadanage...@arm.com>
Cc: Pawel Moll <pawel.m...@arm.com>
Cc: Nicolas Pitre <nicolas.pi...@linaro.org>
Cc: Amit Kucheria <amit.kuche...@linaro.org>
Cc: Jon Medhurst <t...@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieral...@arm.com>
---
drivers/mfd/vexpress-config.c | 26 +++++++---
include/linux/vexpress.h | 23 ++++++--
2 files changed, 37 insertions(+), 12 deletions(-)
diff --git a/drivers/mfd/vexpress-config.c b/drivers/mfd/vexpress-config.c
index 1af2b0e..6f4aa5a 100644
--- a/drivers/mfd/vexpress-config.c
+++ b/drivers/mfd/vexpress-config.c
@@ -266,8 +266,18 @@ int vexpress_config_wait(struct vexpress_config_trans
*trans)
}
EXPORT_SYMBOL(vexpress_config_wait);
-int vexpress_config_read(struct vexpress_config_func *func, int offset,
- u32 *data)
+int vexpress_config_wait_timeout(struct vexpress_config_trans *trans,
+ long jiffies)
+{
+ int ret;
+ ret = wait_for_completion_timeout(&trans->completion, jiffies);
+
+ return ret ? trans->status : -ETIMEDOUT;
+}
+EXPORT_SYMBOL(vexpress_config_wait_timeout);
+
+int vexpress_config_read_timeout(struct vexpress_config_func *func, int offset,
+ u32 *data, long jiffies)
{
struct vexpress_config_trans trans = {
.func = func,
@@ -279,14 +289,14 @@ int vexpress_config_read(struct vexpress_config_func
*func, int offset,
int status = vexpress_config_schedule(&trans);
if (status == VEXPRESS_CONFIG_STATUS_WAIT)
- status = vexpress_config_wait(&trans);
+ status = vexpress_config_wait_timeout(&trans, jiffies);
return status;
}
-EXPORT_SYMBOL(vexpress_config_read);
+EXPORT_SYMBOL(vexpress_config_read_timeout);
-int vexpress_config_write(struct vexpress_config_func *func, int offset,
- u32 data)
+int vexpress_config_write_timeout(struct vexpress_config_func *func,
+ int offset, u32 data, long jiffies)
{
struct vexpress_config_trans trans = {
.func = func,
@@ -298,8 +308,8 @@ int vexpress_config_write(struct vexpress_config_func
*func, int offset,
int status = vexpress_config_schedule(&trans);
if (status == VEXPRESS_CONFIG_STATUS_WAIT)
- status = vexpress_config_wait(&trans);
+ status = vexpress_config_wait_timeout(&trans, jiffies);
return status;
}
-EXPORT_SYMBOL(vexpress_config_write);
+EXPORT_SYMBOL(vexpress_config_write_timeout);
diff --git a/include/linux/vexpress.h b/include/linux/vexpress.h
index 50368e0..e5015d8 100644
--- a/include/linux/vexpress.h
+++ b/include/linux/vexpress.h
@@ -15,6 +15,7 @@
#define _LINUX_VEXPRESS_H
#include <linux/device.h>
+#include <linux/sched.h>
#define VEXPRESS_SITE_MB 0
#define VEXPRESS_SITE_DB1 1
@@ -102,10 +103,24 @@ struct vexpress_config_func *__vexpress_config_func_get(
void vexpress_config_func_put(struct vexpress_config_func *func);
/* Both may sleep! */
-int vexpress_config_read(struct vexpress_config_func *func, int offset,
- u32 *data);
-int vexpress_config_write(struct vexpress_config_func *func, int offset,
- u32 data);
+int vexpress_config_read_timeout(struct vexpress_config_func *func, int offset,
+ u32 *data, long jiffies);
+int vexpress_config_write_timeout(struct vexpress_config_func *func,
+ int offset, u32 data, long jiffies);
+
+static inline int vexpress_config_read(struct vexpress_config_func *func,
+ int offset, u32 *data)
+{
+ return vexpress_config_read_timeout(func, offset, data,
+ MAX_SCHEDULE_TIMEOUT);
+}
+
+static inline int vexpress_config_write(struct vexpress_config_func *func,
+ int offset, u32 data)
+{
+ return vexpress_config_write_timeout(func, offset, data,
+ MAX_SCHEDULE_TIMEOUT);
+}
/* Platform control */
--
1.8.2.2
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
