coresight: cti: Add sysfs trigger / channel programming API

Adds a user API to allow programming of CTI by trigger ID and
channel number. This will take the channel and trigger ID supplied
by the user and program the appropriate register values.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200320165303.13681-5-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 551 insertions, 0 deletions

diff --git a/drivers/hwtracing/coresight/coresight-cti-sysfs.c b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
index 40d31d73b27c..565e17680dea 100644
--- a/drivers/hwtracing/coresight/coresight-cti-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
@@ -474,6 +474,372 @@ static struct attribute *coresight_cti_regs_attrs[] = {
 	NULL,
 };
 
+/* CTI channel x-trigger programming */
+static int
+cti_trig_op_parse(struct device *dev, enum cti_chan_op op,
+		  enum cti_trig_dir dir, const char *buf, size_t size)
+{
+	u32 chan_idx;
+	u32 trig_idx;
+	int items, err = -EINVAL;
+
+	/* extract chan idx and trigger idx */
+	items = sscanf(buf, "%d %d", &chan_idx, &trig_idx);
+	if (items == 2) {
+		err = cti_channel_trig_op(dev, op, dir, chan_idx, trig_idx);
+		if (!err)
+			err = size;
+	}
+	return err;
+}
+
+static ssize_t trigin_attach_store(struct device *dev,
+				   struct device_attribute *attr,
+				   const char *buf, size_t size)
+{
+	return cti_trig_op_parse(dev, CTI_CHAN_ATTACH, CTI_TRIG_IN,
+				 buf, size);
+}
+static DEVICE_ATTR_WO(trigin_attach);
+
+static ssize_t trigin_detach_store(struct device *dev,
+				   struct device_attribute *attr,
+				   const char *buf, size_t size)
+{
+	return cti_trig_op_parse(dev, CTI_CHAN_DETACH, CTI_TRIG_IN,
+				 buf, size);
+}
+static DEVICE_ATTR_WO(trigin_detach);
+
+static ssize_t trigout_attach_store(struct device *dev,
+				    struct device_attribute *attr,
+				    const char *buf, size_t size)
+{
+	return cti_trig_op_parse(dev, CTI_CHAN_ATTACH, CTI_TRIG_OUT,
+				 buf, size);
+}
+static DEVICE_ATTR_WO(trigout_attach);
+
+static ssize_t trigout_detach_store(struct device *dev,
+				    struct device_attribute *attr,
+				    const char *buf, size_t size)
+{
+	return cti_trig_op_parse(dev, CTI_CHAN_DETACH, CTI_TRIG_OUT,
+				 buf, size);
+}
+static DEVICE_ATTR_WO(trigout_detach);
+
+
+static ssize_t chan_gate_enable_store(struct device *dev,
+				      struct device_attribute *attr,
+				      const char *buf, size_t size)
+{
+	int err = 0, channel = 0;
+
+	if (kstrtoint(buf, 0, &channel))
+		return -EINVAL;
+
+	err = cti_channel_gate_op(dev, CTI_GATE_CHAN_ENABLE, channel);
+	return err ? err : size;
+}
+
+static ssize_t chan_gate_enable_show(struct device *dev,
+				     struct device_attribute *attr,
+				     char *buf)
+{
+	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	struct cti_config *cfg = &drvdata->config;
+	unsigned long ctigate_bitmask = cfg->ctigate;
+	int size = 0;
+
+	if (cfg->ctigate == 0)
+		size = sprintf(buf, "\n");
+	else
+		size = bitmap_print_to_pagebuf(true, buf, &ctigate_bitmask,
+					       cfg->nr_ctm_channels);
+	return size;
+}
+static DEVICE_ATTR_RW(chan_gate_enable);
+
+static ssize_t chan_gate_disable_store(struct device *dev,
+				       struct device_attribute *attr,
+				       const char *buf, size_t size)
+{
+	int err = 0, channel = 0;
+
+	if (kstrtoint(buf, 0, &channel))
+		return -EINVAL;
+
+	err = cti_channel_gate_op(dev, CTI_GATE_CHAN_DISABLE, channel);
+	return err ? err : size;
+}
+static DEVICE_ATTR_WO(chan_gate_disable);
+
+static int
+chan_op_parse(struct device *dev, enum cti_chan_set_op op, const char *buf)
+{
+	int err = 0, channel = 0;
+
+	if (kstrtoint(buf, 0, &channel))
+		return -EINVAL;
+
+	err = cti_channel_setop(dev, op, channel);
+	return err;
+
+}
+
+static ssize_t chan_set_store(struct device *dev,
+			      struct device_attribute *attr,
+			      const char *buf, size_t size)
+{
+	int err = chan_op_parse(dev, CTI_CHAN_SET, buf);
+
+	return err ? err : size;
+}
+static DEVICE_ATTR_WO(chan_set);
+
+static ssize_t chan_clear_store(struct device *dev,
+				struct device_attribute *attr,
+				const char *buf, size_t size)
+{
+	int err = chan_op_parse(dev, CTI_CHAN_CLR, buf);
+
+	return err ? err : size;
+}
+static DEVICE_ATTR_WO(chan_clear);
+
+static ssize_t chan_pulse_store(struct device *dev,
+				struct device_attribute *attr,
+				const char *buf, size_t size)
+{
+	int err = chan_op_parse(dev, CTI_CHAN_PULSE, buf);
+
+	return err ? err : size;
+}
+static DEVICE_ATTR_WO(chan_pulse);
+
+static ssize_t trig_filter_enable_show(struct device *dev,
+				       struct device_attribute *attr,
+				       char *buf)
+{
+	u32 val;
+	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+	spin_lock(&drvdata->spinlock);
+	val = drvdata->config.trig_filter_enable;
+	spin_unlock(&drvdata->spinlock);
+	return sprintf(buf, "%d\n", val);
+}
+
+static ssize_t trig_filter_enable_store(struct device *dev,
+					struct device_attribute *attr,
+					const char *buf, size_t size)
+{
+	unsigned long val;
+	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+	if (kstrtoul(buf, 0, &val))
+		return -EINVAL;
+
+	spin_lock(&drvdata->spinlock);
+	drvdata->config.trig_filter_enable = !!val;
+	spin_unlock(&drvdata->spinlock);
+	return size;
+}
+static DEVICE_ATTR_RW(trig_filter_enable);
+
+static ssize_t trigout_filtered_show(struct device *dev,
+				     struct device_attribute *attr,
+				     char *buf)
+{
+	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	struct cti_config *cfg = &drvdata->config;
+	int size = 0, nr_trig_max = cfg->nr_trig_max;
+	unsigned long mask = cfg->trig_out_filter;
+
+	if (mask)
+		size = bitmap_print_to_pagebuf(true, buf, &mask, nr_trig_max);
+	return size;
+}
+static DEVICE_ATTR_RO(trigout_filtered);
+
+/* clear all xtrigger / channel programming */
+static ssize_t chan_xtrigs_reset_store(struct device *dev,
+				       struct device_attribute *attr,
+				       const char *buf, size_t size)
+{
+	int i;
+	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	struct cti_config *config = &drvdata->config;
+
+	spin_lock(&drvdata->spinlock);
+
+	/* clear the CTI trigger / channel programming registers */
+	for (i = 0; i < config->nr_trig_max; i++) {
+		config->ctiinen[i] = 0;
+		config->ctiouten[i] = 0;
+	}
+
+	/* clear the other regs */
+	config->ctigate = GENMASK(config->nr_ctm_channels - 1, 0);
+	config->asicctl = 0;
+	config->ctiappset = 0;
+	config->ctiinout_sel = 0;
+	config->xtrig_rchan_sel = 0;
+
+	/* if enabled then write through */
+	if (cti_active(config))
+		cti_write_all_hw_regs(drvdata);
+
+	spin_unlock(&drvdata->spinlock);
+	return size;
+}
+static DEVICE_ATTR_WO(chan_xtrigs_reset);
+
+/*
+ * Write to select a channel to view, read to display the
+ * cross triggers for the selected channel.
+ */
+static ssize_t chan_xtrigs_sel_store(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t size)
+{
+	unsigned long val;
+	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+	if (kstrtoul(buf, 0, &val))
+		return -EINVAL;
+	if (val > (drvdata->config.nr_ctm_channels - 1))
+		return -EINVAL;
+
+	spin_lock(&drvdata->spinlock);
+	drvdata->config.xtrig_rchan_sel = val;
+	spin_unlock(&drvdata->spinlock);
+	return size;
+}
+
+static ssize_t chan_xtrigs_sel_show(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
+	unsigned long val;
+	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+	spin_lock(&drvdata->spinlock);
+	val = drvdata->config.xtrig_rchan_sel;
+	spin_unlock(&drvdata->spinlock);
+
+	return sprintf(buf, "%ld\n", val);
+}
+static DEVICE_ATTR_RW(chan_xtrigs_sel);
+
+static ssize_t chan_xtrigs_in_show(struct device *dev,
+				   struct device_attribute *attr,
+				   char *buf)
+{
+	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	struct cti_config *cfg = &drvdata->config;
+	int used = 0, reg_idx;
+	int nr_trig_max = drvdata->config.nr_trig_max;
+	u32 chan_mask = BIT(cfg->xtrig_rchan_sel);
+
+	for (reg_idx = 0; reg_idx < nr_trig_max; reg_idx++) {
+		if (chan_mask & cfg->ctiinen[reg_idx])
+			used += sprintf(buf + used, "%d ", reg_idx);
+	}
+
+	used += sprintf(buf + used, "\n");
+	return used;
+}
+static DEVICE_ATTR_RO(chan_xtrigs_in);
+
+static ssize_t chan_xtrigs_out_show(struct device *dev,
+				    struct device_attribute *attr,
+				    char *buf)
+{
+	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	struct cti_config *cfg = &drvdata->config;
+	int used = 0, reg_idx;
+	int nr_trig_max = drvdata->config.nr_trig_max;
+	u32 chan_mask = BIT(cfg->xtrig_rchan_sel);
+
+	for (reg_idx = 0; reg_idx < nr_trig_max; reg_idx++) {
+		if (chan_mask & cfg->ctiouten[reg_idx])
+			used += sprintf(buf + used, "%d ", reg_idx);
+	}
+
+	used += sprintf(buf + used, "\n");
+	return used;
+}
+static DEVICE_ATTR_RO(chan_xtrigs_out);
+
+static ssize_t print_chan_list(struct device *dev,
+			       char *buf, bool inuse)
+{
+	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	struct cti_config *config = &drvdata->config;
+	int size, i;
+	unsigned long inuse_bits = 0, chan_mask;
+
+	/* scan regs to get bitmap of channels in use. */
+	spin_lock(&drvdata->spinlock);
+	for (i = 0; i < config->nr_trig_max; i++) {
+		inuse_bits |= config->ctiinen[i];
+		inuse_bits |= config->ctiouten[i];
+	}
+	spin_unlock(&drvdata->spinlock);
+
+	/* inverse bits if printing free channels */
+	if (!inuse)
+		inuse_bits = ~inuse_bits;
+
+	/* list of channels, or 'none' */
+	chan_mask = GENMASK(config->nr_ctm_channels - 1, 0);
+	if (inuse_bits & chan_mask)
+		size = bitmap_print_to_pagebuf(true, buf, &inuse_bits,
+					       config->nr_ctm_channels);
+	else
+		size = sprintf(buf, "\n");
+	return size;
+}
+
+static ssize_t chan_inuse_show(struct device *dev,
+			       struct device_attribute *attr,
+			       char *buf)
+{
+	return print_chan_list(dev, buf, true);
+}
+static DEVICE_ATTR_RO(chan_inuse);
+
+static ssize_t chan_free_show(struct device *dev,
+			      struct device_attribute *attr,
+			      char *buf)
+{
+	return print_chan_list(dev, buf, false);
+}
+static DEVICE_ATTR_RO(chan_free);
+
+static struct attribute *coresight_cti_channel_attrs[] = {
+	&dev_attr_trigin_attach.attr,
+	&dev_attr_trigin_detach.attr,
+	&dev_attr_trigout_attach.attr,
+	&dev_attr_trigout_detach.attr,
+	&dev_attr_trig_filter_enable.attr,
+	&dev_attr_trigout_filtered.attr,
+	&dev_attr_chan_gate_enable.attr,
+	&dev_attr_chan_gate_disable.attr,
+	&dev_attr_chan_set.attr,
+	&dev_attr_chan_clear.attr,
+	&dev_attr_chan_pulse.attr,
+	&dev_attr_chan_inuse.attr,
+	&dev_attr_chan_free.attr,
+	&dev_attr_chan_xtrigs_sel.attr,
+	&dev_attr_chan_xtrigs_in.attr,
+	&dev_attr_chan_xtrigs_out.attr,
+	&dev_attr_chan_xtrigs_reset.attr,
+	NULL,
+};
+
 /* sysfs groups */
 static const struct attribute_group coresight_cti_group = {
 	.attrs = coresight_cti_attrs,
@@ -489,9 +855,15 @@ static const struct attribute_group coresight_cti_regs_group = {
 	.name = "regs",
 };
 
+static const struct attribute_group coresight_cti_channels_group = {
+	.attrs = coresight_cti_channel_attrs,
+	.name = "channels",
+};
+
 const struct attribute_group *coresight_cti_groups[] = {
 	&coresight_cti_group,
 	&coresight_cti_mgmt_group,
 	&coresight_cti_regs_group,
+	&coresight_cti_channels_group,
 	NULL,
 };
diff --git a/drivers/hwtracing/coresight/coresight-cti.c b/drivers/hwtracing/coresight/coresight-cti.c
index e0748cc92384..b8c94027fed0 100644
--- a/drivers/hwtracing/coresight/coresight-cti.c
+++ b/drivers/hwtracing/coresight/coresight-cti.c
@@ -294,6 +294,153 @@ int cti_add_default_connection(struct device *dev, struct cti_drvdata *drvdata)
 	return ret;
 }
 
+/** cti channel api **/
+/* attach/detach channel from trigger - write through if enabled. */
+int cti_channel_trig_op(struct device *dev, enum cti_chan_op op,
+			enum cti_trig_dir direction, u32 channel_idx,
+			u32 trigger_idx)
+{
+	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	struct cti_config *config = &drvdata->config;
+	u32 trig_bitmask;
+	u32 chan_bitmask;
+	u32 reg_value;
+	int reg_offset;
+
+	/* ensure indexes in range */
+	if ((channel_idx >= config->nr_ctm_channels) ||
+	   (trigger_idx >= config->nr_trig_max))
+		return -EINVAL;
+
+	trig_bitmask = BIT(trigger_idx);
+
+	/* ensure registered triggers and not out filtered */
+	if (direction == CTI_TRIG_IN)	{
+		if (!(trig_bitmask & config->trig_in_use))
+			return -EINVAL;
+	} else {
+		if (!(trig_bitmask & config->trig_out_use))
+			return -EINVAL;
+
+		if ((config->trig_filter_enable) &&
+		    (config->trig_out_filter & trig_bitmask))
+			return -EINVAL;
+	}
+
+	/* update the local register values */
+	chan_bitmask = BIT(channel_idx);
+	reg_offset = (direction == CTI_TRIG_IN ? CTIINEN(trigger_idx) :
+		      CTIOUTEN(trigger_idx));
+
+	spin_lock(&drvdata->spinlock);
+
+	/* read - modify write - the trigger / channel enable value */
+	reg_value = direction == CTI_TRIG_IN ? config->ctiinen[trigger_idx] :
+		     config->ctiouten[trigger_idx];
+	if (op == CTI_CHAN_ATTACH)
+		reg_value |= chan_bitmask;
+	else
+		reg_value &= ~chan_bitmask;
+
+	/* write local copy */
+	if (direction == CTI_TRIG_IN)
+		config->ctiinen[trigger_idx] = reg_value;
+	else
+		config->ctiouten[trigger_idx] = reg_value;
+
+	/* write through if enabled */
+	if (cti_active(config))
+		cti_write_single_reg(drvdata, reg_offset, reg_value);
+	spin_unlock(&drvdata->spinlock);
+	return 0;
+}
+
+int cti_channel_gate_op(struct device *dev, enum cti_chan_gate_op op,
+			u32 channel_idx)
+{
+	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	struct cti_config *config = &drvdata->config;
+	u32 chan_bitmask;
+	u32 reg_value;
+	int err = 0;
+
+	if (channel_idx >= config->nr_ctm_channels)
+		return -EINVAL;
+
+	chan_bitmask = BIT(channel_idx);
+
+	spin_lock(&drvdata->spinlock);
+	reg_value = config->ctigate;
+	switch (op) {
+	case CTI_GATE_CHAN_ENABLE:
+		reg_value |= chan_bitmask;
+		break;
+
+	case CTI_GATE_CHAN_DISABLE:
+		reg_value &= ~chan_bitmask;
+		break;
+
+	default:
+		err = -EINVAL;
+		break;
+	}
+	if (err == 0) {
+		config->ctigate = reg_value;
+		if (cti_active(config))
+			cti_write_single_reg(drvdata, CTIGATE, reg_value);
+	}
+	spin_unlock(&drvdata->spinlock);
+	return err;
+}
+
+int cti_channel_setop(struct device *dev, enum cti_chan_set_op op,
+		      u32 channel_idx)
+{
+	struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	struct cti_config *config = &drvdata->config;
+	u32 chan_bitmask;
+	u32 reg_value;
+	u32 reg_offset;
+	int err = 0;
+
+	if (channel_idx >= config->nr_ctm_channels)
+		return -EINVAL;
+
+	chan_bitmask = BIT(channel_idx);
+
+	spin_lock(&drvdata->spinlock);
+	reg_value = config->ctiappset;
+	switch (op) {
+	case CTI_CHAN_SET:
+		config->ctiappset |= chan_bitmask;
+		reg_value  = config->ctiappset;
+		reg_offset = CTIAPPSET;
+		break;
+
+	case CTI_CHAN_CLR:
+		config->ctiappset &= ~chan_bitmask;
+		reg_value = chan_bitmask;
+		reg_offset = CTIAPPCLEAR;
+		break;
+
+	case CTI_CHAN_PULSE:
+		config->ctiappset &= ~chan_bitmask;
+		reg_value = chan_bitmask;
+		reg_offset = CTIAPPPULSE;
+		break;
+
+	default:
+		err = -EINVAL;
+		break;
+	}
+
+	if ((err == 0) && cti_active(config))
+		cti_write_single_reg(drvdata, reg_offset, reg_value);
+	spin_unlock(&drvdata->spinlock);
+
+	return err;
+}
+
 /** cti ect operations **/
 int cti_enable(struct coresight_device *csdev)
 {
diff --git a/drivers/hwtracing/coresight/coresight-cti.h b/drivers/hwtracing/coresight/coresight-cti.h
index 35eb77b276c4..f664b4bb4644 100644
--- a/drivers/hwtracing/coresight/coresight-cti.h
+++ b/drivers/hwtracing/coresight/coresight-cti.h
@@ -168,6 +168,30 @@ struct cti_drvdata {
 	void (*csdev_release)(struct device *dev);
 };
 
+/*
+ * Channel operation types.
+ */
+enum cti_chan_op {
+	CTI_CHAN_ATTACH,
+	CTI_CHAN_DETACH,
+};
+
+enum cti_trig_dir {
+	CTI_TRIG_IN,
+	CTI_TRIG_OUT,
+};
+
+enum cti_chan_gate_op {
+	CTI_GATE_CHAN_ENABLE,
+	CTI_GATE_CHAN_DISABLE,
+};
+
+enum cti_chan_set_op {
+	CTI_CHAN_SET,
+	CTI_CHAN_CLR,
+	CTI_CHAN_PULSE,
+};
+
 /* private cti driver fns & vars */
 extern const struct attribute_group *coresight_cti_groups[];
 int cti_add_default_connection(struct device *dev,
@@ -180,8 +204,16 @@ struct cti_trig_con *cti_allocate_trig_con(struct device *dev, int in_sigs,
 					   int out_sigs);
 int cti_enable(struct coresight_device *csdev);
 int cti_disable(struct coresight_device *csdev);
+void cti_write_all_hw_regs(struct cti_drvdata *drvdata);
 void cti_write_intack(struct device *dev, u32 ackval);
 void cti_write_single_reg(struct cti_drvdata *drvdata, int offset, u32 value);
+int cti_channel_trig_op(struct device *dev, enum cti_chan_op op,
+			enum cti_trig_dir direction, u32 channel_idx,
+			u32 trigger_idx);
+int cti_channel_gate_op(struct device *dev, enum cti_chan_gate_op op,
+			u32 channel_idx);
+int cti_channel_setop(struct device *dev, enum cti_chan_set_op op,
+		      u32 channel_idx);
 struct coresight_platform_data *
 coresight_cti_get_platform_data(struct device *dev);