-----Original Message----- From: Leo Yan leo.yan@arm.com Sent: Monday, February 9, 2026 6:01 PM To: Suzuki Poulose Suzuki.Poulose@arm.com; Mike Leach Mike.Leach@arm.com; James Clark james.clark@linaro.org; Alexander Shishkin alexander.shishkin@linux.intel.com; Greg Kroah-Hartman gregkh@linuxfoundation.org; Mathieu Poirier mathieu.poirier@linaro.org; Tingwei Zhang quic_tingwei@quicinc.com; Yingchao Deng yingchao.deng@oss.qualcomm.com; Jie Gan jie.gan@oss.qualcomm.com Cc: coresight@lists.linaro.org; linux-arm-kernel@lists.infradead.org; linux- kernel@vger.kernel.org; Leo Yan Leo.Yan@arm.com Subject: [PATCH 3/8] coresight: cti: Access ASICCTL only when implemented
According to the Arm ARM (DDI 0487 L.b), ASICCTL is implemented only when CTIDEVID.EXTMUXNUM is non-zero.
Based on CTIDEVID.EXTMUXNUM, add a flag 'asicctl_impl' to indicate whether the register is implemented, and access ASICCTL conditionally based on the flag.
Allow the sysfs node to be visible only when the register is implemented.
Signed-off-by: Leo Yan leo.yan@arm.com
drivers/hwtracing/coresight/coresight-cti-core.c | 5 ++++- drivers/hwtracing/coresight/coresight-cti-sysfs.c | 13 +++++++++++++ drivers/hwtracing/coresight/coresight-cti.h | 2 ++ 3 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c b/drivers/hwtracing/coresight/coresight-cti-core.c index 2d8b1cbe5bf5c9ce0383dc90335f0085b22a7f61..1950e9b757ae4879a267 1ddaf5675c54aa7956d5 100644 --- a/drivers/hwtracing/coresight/coresight-cti-core.c +++ b/drivers/hwtracing/coresight/coresight-cti-core.c @@ -77,7 +77,8 @@ void cti_write_all_hw_regs(struct cti_drvdata *drvdata)
/* other regs */ writel_relaxed(config->ctigate, drvdata->base + CTIGATE);
- writel_relaxed(config->asicctl, drvdata->base + ASICCTL);
if (config->asicctl_impl)
writel_relaxed(config->asicctl, drvdata->base + ASICCTL);writel_relaxed(config->ctiappset, drvdata->base + CTIAPPSET);
/* re-enable CTI */
@@ -230,6 +231,8 @@ static void cti_set_default_config(struct device *dev, config->trig_filter_enable = true; config->ctigate = GENMASK(config->nr_ctm_channels - 1, 0); config->enable_req_count = 0;
- config->asicctl_impl = !!FIELD_GET(GENMASK(4, 0), devid);
}
/* diff --git a/drivers/hwtracing/coresight/coresight-cti-sysfs.c b/drivers/hwtracing/coresight/coresight-cti-sysfs.c index 9a997b2f090472761e9734fffc534663df8b06c6..c15a580f6e90f57b1376e0 b883a27700966feb1a 100644 --- a/drivers/hwtracing/coresight/coresight-cti-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-cti-sysfs.c @@ -537,6 +537,18 @@ static struct attribute *coresight_cti_regs_attrs[] = { NULL, };
+static umode_t coresight_cti_regs_is_visible(struct kobject *kobj,
struct attribute *attr, int idx)+{
- struct device *dev = kobj_to_dev(kobj);
- struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
- if (attr == &dev_attr_asicctl.attr && !drvdata->config.asicctl_impl)
return 0;- return attr->mode;
+}
/* CTI channel x-trigger programming */ static int cti_trig_op_parse(struct device *dev, enum cti_chan_op op, @@ -1174,6 +1186,7 @@ static const struct attribute_group coresight_cti_mgmt_group = {
static const struct attribute_group coresight_cti_regs_group = { .attrs = coresight_cti_regs_attrs,
- .is_visible = coresight_cti_regs_is_visible, .name = "regs",
};
diff --git a/drivers/hwtracing/coresight/coresight-cti.h b/drivers/hwtracing/coresight/coresight-cti.h index 64f7324f098e8b5f90c6554e3872e3bf01988717..7a3e7f806dcb093e504f1 aacb3b29564bea28f6c 100644 --- a/drivers/hwtracing/coresight/coresight-cti.h +++ b/drivers/hwtracing/coresight/coresight-cti.h @@ -119,6 +119,7 @@ struct cti_device {
- @nr_trig_max: Max number of trigger signals implemented on device.
(max of trig_in or trig_out) - from ID register.- @nr_ctm_channels: number of available CTM channels - from ID register.
- @asicctl_impl: true if asicctl is implemented.
- @enable_req_count: CTI is enabled alongside >=1 associated devices.
- @hw_enabled: true if hw is currently enabled.
- @hw_powered: true if associated cpu powered on, or no cpu.
@@ -140,6 +141,7 @@ struct cti_config { /* hardware description */ int nr_ctm_channels; int nr_trig_max;
bool asicctl_impl;
/* cti enable control */ int enable_req_count;
-- 2.34.1
Reviewed-by: Mike Leach mike.leach@arm.com