On 25.01.19 10:38, Philippe Gerum wrote:
On 1/25/19 10:33 AM, Jan Kiszka wrote:
On 25.01.19 10:31, Philippe Gerum wrote:
On 1/25/19 10:23 AM, Jan Kiszka wrote:
On 25.01.19 10:15, Philippe Gerum wrote:
On 1/24/19 7:17 PM, Jan Kiszka wrote:
On 24.01.19 16:34, Philippe Gerum wrote:
In timestamping mode, read() returns the timestamp of the latest
event
receipt on the pin based on CLOCK_MONOTONIC, along with the pin
state. This is an optional pin readout mode controlled by the
GPIO_RTIOC_TS request, e.g.:

struct rtdm_gpio_readout rdo;
int ret, on, val;

on = 1;
ret = ioctl(pinfd, GPIO_RTIOC_TS, &on);
ret = read(pinfd, &rdo, sizeof(rdo));
/* pin state changed to rdo.value at time rdo.timestamp */

on = 0;
ret = ioctl(pinfd, GPIO_RTIOC_TS, &on);
ret = read(pinfd, &val, sizeof(val));
/* pin state changed to value (time of change unspecified) */

By default, timestamping mode is disabled, which corresponds to the
original behavior.

Signed-off-by: Philippe Gerum <[email protected]>
---
     include/cobalt/kernel/rtdm/gpio.h |  1 +
     include/rtdm/uapi/gpio.h          | 18 +++++++----
     kernel/drivers/gpio/gpio-core.c   | 54
+++++++++++++++++++++++--------
     3 files changed, 54 insertions(+), 19 deletions(-)

diff --git a/include/cobalt/kernel/rtdm/gpio.h
b/include/cobalt/kernel/rtdm/gpio.h
index cdb472f8a..00055ec0a 100644
--- a/include/cobalt/kernel/rtdm/gpio.h
+++ b/include/cobalt/kernel/rtdm/gpio.h
@@ -33,6 +33,7 @@ struct rtdm_gpio_pin {
         rtdm_event_t event;
         char *name;
         struct gpio_desc *desc;
+    nanosecs_abs_t timestamp;
     };
       struct rtdm_gpio_chip {
diff --git a/include/rtdm/uapi/gpio.h b/include/rtdm/uapi/gpio.h
index b745f156c..ac14be66c 100644
--- a/include/rtdm/uapi/gpio.h
+++ b/include/rtdm/uapi/gpio.h
@@ -18,12 +18,18 @@
     #ifndef _RTDM_UAPI_GPIO_H
     #define _RTDM_UAPI_GPIO_H
     -#define GPIO_RTIOC_DIR_OUT        _IOW(RTDM_CLASS_GPIO, 0, int)
-#define GPIO_RTIOC_DIR_IN        _IO(RTDM_CLASS_GPIO, 1)
-#define GPIO_RTIOC_IRQEN        _IOW(RTDM_CLASS_GPIO, 2, int) /*
GPIO
trigger */
-#define GPIO_RTIOC_IRQDIS        _IO(RTDM_CLASS_GPIO, 3)
-#define GPIO_RTIOC_REQS                _IO(RTDM_CLASS_GPIO, 4)
-#define GPIO_RTIOC_RELS                _IO(RTDM_CLASS_GPIO, 5)
+struct rtdm_gpio_readout {
+    __u64 timestamp;

nanosecs_abs_t - we use this type also in to userspace interface.


Nope. This is ABI stuff, nanosecs_abs_t is not guaranteed to have the
same size regardless of the ABI models, which is unsafe in mixed 32/64
model configurations. OTOH, __u64 is safe.

If nanosecs_abs_t is alread an ABI, and it is used as such for a long
time (see include/rtdm/uapi/serial.h). If you see a bug in its
definition, that needs to be fixed. We should not resolve that by
choosing open-coded local workarounds.


nanosecs_t is not defined in the Xenomai ABI, never has been. Using
nanosecs_t in structs actually abuses such ABI. So we may either keep
adding even more nanosecs, or fix the spots where it should be replaced
with __u64.

Xenomai ABI includes the driver ABI - so your assumption might have been
it's not while it was de facto.

Again, let's address the issue, not work around it.


__u64 is the fix, using nanosecs*_t in uapi/ is wrong. So please merge
this fix, and we'll see how we can progress fixing other abuses.

Nope: Adjust nanosecs_*_t if it has a problem ([u]int64_t vs. __u/s64 - what's the problem exactly?), and use that. That will both address existing users and future ones. No special solution for the GPIO driver here.

Jan

--
Siemens AG, Corporate Technology, CT RDA IOT SES-DE
Corporate Competence Center Embedded Linux

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