There is already an interface of set_options, but no get_options yet.
Before setting any options, one would may want to see the current
status of that option by means of get_options interface. This
interface has been used in CoreSight STM driver.
Signed-off-by: Chunyan Zhang <zhang.chunyan@xxxxxxxxxx>
---
drivers/hwtracing/stm/core.c | 11 +++++++++++
include/linux/stm.h | 3 +++
include/uapi/linux/stm.h | 1 +
3 files changed, 15 insertions(+)
diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
index b6445d9..86bb4e3 100644
--- a/drivers/hwtracing/stm/core.c
+++ b/drivers/hwtracing/stm/core.c
@@ -571,6 +571,17 @@ stm_char_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
options);
break;
+
+ case STP_GET_OPTIONS:
+ if (stm_data->get_options)
+ err = stm_data->get_options(stm_data,
+ stmf->output.master,
+ stmf->output.channel,
+ stmf->output.nr_chans,
+ &options);
+
+ return copy_to_user((void __user *)arg, &options, sizeof(u64));
+
default:
break;
}
diff --git a/include/linux/stm.h b/include/linux/stm.h
index 9d0083d..f351d62 100644
--- a/include/linux/stm.h
+++ b/include/linux/stm.h
@@ -88,6 +88,9 @@ struct stm_data {
long (*set_options)(struct stm_data *, unsigned int,
unsigned int, unsigned int,
unsigned long);
+ long (*get_options)(struct stm_data *, unsigned int,
+ unsigned int, unsigned int,
+ u64 *);
};
int stm_register_device(struct device *parent, struct stm_data *stm_data,
diff --git a/include/uapi/linux/stm.h b/include/uapi/linux/stm.h
index 626a8d3..0dab16e 100644
--- a/include/uapi/linux/stm.h
+++ b/include/uapi/linux/stm.h
@@ -46,5 +46,6 @@ struct stp_policy_id {
#define STP_POLICY_ID_SET _IOWR('%', 0, struct stp_policy_id)
#define STP_POLICY_ID_GET _IOR('%', 1, struct stp_policy_id)
#define STP_SET_OPTIONS _IOW('%', 2, __u64)
+#define STP_GET_OPTIONS _IOR('%', 3, __u64)
#endif /* _UAPI_LINUX_STM_H */
--
1.9.1
--
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