On Fri, 21 Jul 2023 20:00:16 +0300
Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> wrote:
> Use sysfs_match_string() helper instead of open coded variant.
>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Reviewed-by: Nuno Sa <nuno.sa@xxxxxxxxxx>
It 'should' be impossible to end up with one of the clocks
that we reject for the store..
So I wonder if it would be cleaner to only add the clocks we
actually use to the clock_names[] array and use the failure to match
(-EINVAL) to call BUG() which then matches the existing behaviour.
If the clock matching was a generic function I'd be fine with doing what
you have here, but it's local to IIO so we don't have to play nice with
clocks we don't understand.
Jonathan
> ---
> drivers/iio/industrialio-core.c | 81 +++++++++++++--------------------
> 1 file changed, 31 insertions(+), 50 deletions(-)
>
> diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
> index 6cca86fd0ef9..4e45740331ee 100644
> --- a/drivers/iio/industrialio-core.c
> +++ b/drivers/iio/industrialio-core.c
> @@ -1400,50 +1400,32 @@ static ssize_t label_show(struct device *dev, struct device_attribute *attr,
>
> static DEVICE_ATTR_RO(label);
>
> +static const char * const clock_names[] = {
> + [CLOCK_REALTIME] = "realtime",
> + [CLOCK_MONOTONIC] = "monotonic",
> + [CLOCK_PROCESS_CPUTIME_ID] = "process_cputime_id",
> + [CLOCK_THREAD_CPUTIME_ID] = "thread_cputime_id",
> + [CLOCK_MONOTONIC_RAW] = "monotonic_raw",
> + [CLOCK_REALTIME_COARSE] = "realtime_coarse",
> + [CLOCK_MONOTONIC_COARSE] = "monotonic_coarse",
> + [CLOCK_BOOTTIME] = "boottime",
> + [CLOCK_REALTIME_ALARM] = "realtime_alarm",
> + [CLOCK_BOOTTIME_ALARM] = "boottime_alarm",
> + [CLOCK_SGI_CYCLE] = "sgi_cycle",
> + [CLOCK_TAI] = "tai",
> +};
> +
> static ssize_t current_timestamp_clock_show(struct device *dev,
> struct device_attribute *attr,
> char *buf)
> {
> const struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> const clockid_t clk = iio_device_get_clock(indio_dev);
> - const char *name;
> - ssize_t sz;
>
> - switch (clk) {
> - case CLOCK_REALTIME:
> - name = "realtime\n";
> - sz = sizeof("realtime\n");
> - break;
> - case CLOCK_MONOTONIC:
> - name = "monotonic\n";
> - sz = sizeof("monotonic\n");
> - break;
> - case CLOCK_MONOTONIC_RAW:
> - name = "monotonic_raw\n";
> - sz = sizeof("monotonic_raw\n");
> - break;
> - case CLOCK_REALTIME_COARSE:
> - name = "realtime_coarse\n";
> - sz = sizeof("realtime_coarse\n");
> - break;
> - case CLOCK_MONOTONIC_COARSE:
> - name = "monotonic_coarse\n";
> - sz = sizeof("monotonic_coarse\n");
> - break;
> - case CLOCK_BOOTTIME:
> - name = "boottime\n";
> - sz = sizeof("boottime\n");
> - break;
> - case CLOCK_TAI:
> - name = "tai\n";
> - sz = sizeof("tai\n");
> - break;
> - default:
> + if (clk < 0 && clk >= ARRAY_SIZE(clock_names))
> BUG();
This is a functional change as more clocks are allowed without
things going boom.
> - }
>
> - memcpy(buf, name, sz);
> - return sz;
> + return sysfs_emit(buf, "%s\n", clock_names[clk]);
> }
>
> static ssize_t current_timestamp_clock_store(struct device *dev,
> @@ -1453,22 +1435,21 @@ static ssize_t current_timestamp_clock_store(struct device *dev,
> clockid_t clk;
> int ret;
>
> - if (sysfs_streq(buf, "realtime"))
> - clk = CLOCK_REALTIME;
> - else if (sysfs_streq(buf, "monotonic"))
> - clk = CLOCK_MONOTONIC;
> - else if (sysfs_streq(buf, "monotonic_raw"))
> - clk = CLOCK_MONOTONIC_RAW;
> - else if (sysfs_streq(buf, "realtime_coarse"))
> - clk = CLOCK_REALTIME_COARSE;
> - else if (sysfs_streq(buf, "monotonic_coarse"))
> - clk = CLOCK_MONOTONIC_COARSE;
> - else if (sysfs_streq(buf, "boottime"))
> - clk = CLOCK_BOOTTIME;
> - else if (sysfs_streq(buf, "tai"))
> - clk = CLOCK_TAI;
> - else
> + ret = sysfs_match_string(clock_names, buf);
> + if (ret < 0)
> + return ret;
> +
> + switch (ret) {
> + case CLOCK_PROCESS_CPUTIME_ID:
> + case CLOCK_THREAD_CPUTIME_ID:
> + case CLOCK_REALTIME_ALARM:
> + case CLOCK_BOOTTIME_ALARM:
> + case CLOCK_SGI_CYCLE:
> return -EINVAL;
> + default:
> + clk = ret;
> + break;
> + }
>
> ret = iio_device_set_clock(dev_to_iio_dev(dev), clk);
> if (ret)
