Re: [PATCH 7/9] coresight-tpdm: Add nodes for dsb element creation
From: Suzuki K Poulose
Date: Mon Oct 24 2022 - 13:14:33 EST
On 08/09/2022 09:45, Tao Zhang wrote:
Add the nodes to set value for DSB edge control and DSB edge
control mask. Each DSB subunit TPDM has n(n<16) EDCR resgisters
to configure edge control. And each DSB subunit TPDM has m(m<8)
ECDMR registers to configure edge control mask.
Please could you describe what these values represent ? Size of
the "value". Without the specs, it is really difficult to comprehend
the code.
Please add comments
Signed-off-by: Tao Zhang <quic_taozha@xxxxxxxxxxx>
---
drivers/hwtracing/coresight/coresight-tpdm.c | 130 ++++++++++++++++++++++++++-
drivers/hwtracing/coresight/coresight-tpdm.h | 11 +++
2 files changed, 140 insertions(+), 1 deletion(-)
diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
index 7265793..14bcf2b 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.c
+++ b/drivers/hwtracing/coresight/coresight-tpdm.c
@@ -22,7 +22,14 @@ DEFINE_CORESIGHT_DEVLIST(tpdm_devs, "tpdm");
static void tpdm_enable_dsb(struct tpdm_drvdata *drvdata)
{
- u32 val, mode;
+ u32 val, mode, i;
+
+ for (i = 0; i < TPDM_DSB_MAX_EDCR; i++)
+ writel_relaxed(drvdata->dsb->edge_ctrl[i],
+ drvdata->base + TPDM_DSB_EDCR(i));
+ for (i = 0; i < TPDM_DSB_MAX_EDCR / 2; i++)
Please use "TPDM_DSB_MAX_EDMCR" for consistency and ease of following
the code.
+ writel_relaxed(drvdata->dsb->edge_ctrl_mask[i],
+ drvdata->base + TPDM_DSB_EDCMR(i));
val = readl_relaxed(drvdata->base + TPDM_DSB_TIER);
/* Set trigger timestamp */
@@ -278,6 +285,125 @@ static ssize_t dsb_mode_store(struct device *dev,
}
static DEVICE_ATTR_RW(dsb_mode);
+static ssize_t dsb_edge_ctrl_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+ ssize_t size = 0;
+ int i;
+
+ if (!(drvdata->datasets & TPDM_PIDR0_DS_DSB))
+ return -EPERM;
+
+ spin_lock(&drvdata->spinlock);
+ for (i = 0; i < TPDM_DSB_MAX_EDCR; i++) {
+ size += scnprintf(buf + size, PAGE_SIZE - size,
+ "Index:0x%x Val:0x%x\n", i,
+ drvdata->dsb->edge_ctrl[i]);
+ }
+ spin_unlock(&drvdata->spinlock);
+ return size;
+}
+
+/*
+ * value 1: Start EDCR register number
+ * value 2: End EDCR register number
+ * value 3: The value need to be written
What are the constraints on these inputs ? Please add
a comment here. And may be also add a user scenario if possible to
describe the values and its effects on the unit ?
+ */
+static ssize_t dsb_edge_ctrl_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t size)
+{
+ struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+ unsigned long start, end, edge_ctrl;
+ uint32_t val;
+ int i, bit, reg;
+
+ if (sscanf(buf, "%lx %lx %lx", &start, &end, &edge_ctrl) != 3)
+ return -EINVAL;
+ if (!(drvdata->datasets & TPDM_PIDR0_DS_DSB) ||
+ (start >= TPDM_DSB_MAX_LINES) || (end >= TPDM_DSB_MAX_LINES) ||
+ edge_ctrl > 0x2)
+ return -EPERM;
+
+ spin_lock(&drvdata->spinlock);
+ for (i = start; i <= end; i++) {
+ reg = i / (NUM_OF_BITS / 2);
+ bit = i % (NUM_OF_BITS / 2);
NUM_OF_BITS in what ? That is too generic.
+ bit = bit * 2;
minor nit: Name "bit" is confusing here. s/bit/{index or even field}?
+
+ val = drvdata->dsb->edge_ctrl[reg];
+ val = val & ~GENMASK((bit + 1), bit);
+ val = val | (edge_ctrl << bit);
+ drvdata->dsb->edge_ctrl[reg] = val;
+ }
+ spin_unlock(&drvdata->spinlock);
+
+ return size;
+}
+static DEVICE_ATTR_RW(dsb_edge_ctrl);
+
+static ssize_t dsb_edge_ctrl_mask_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+ ssize_t size = 0;
+ int i;
+
+ if (!(drvdata->datasets & TPDM_PIDR0_DS_DSB))
+ return -EPERM;
+
+ spin_lock(&drvdata->spinlock);
+ for (i = 0; i < TPDM_DSB_MAX_EDCR / 2; i++) {
+ size += scnprintf(buf + size, PAGE_SIZE - size,
+ "Index:0x%x Val:0x%x\n", i,
+ drvdata->dsb->edge_ctrl_mask[i]);
+ }
+ spin_unlock(&drvdata->spinlock);
+ return size;
+}
+
+/*
+ * value 1: Start EDCMR register number
+ * value 2: End EDCMR register number
+ * value 3: The value need to be written
+ */
+static ssize_t dsb_edge_ctrl_mask_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t size)
+{
+ struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+ unsigned long start, end, val;
+ u32 set;
+ int i, bit, reg;
+
+ if (sscanf(buf, "%lx %lx %lx", &start, &end, &val) != 3)
+ return -EINVAL;
+ if (!(drvdata->datasets & TPDM_PIDR0_DS_DSB) ||
Please use is_visible() hook.
+ (start >= TPDM_DSB_MAX_LINES) || (end >= TPDM_DSB_MAX_LINES))
+ return -EPERM;
No constraints on "val"? 0 or 1 ?
+
+ spin_lock(&drvdata->spinlock);
+ for (i = start; i <= end; i++) {
+ reg = i / NUM_OF_BITS;
+ bit = (i % NUM_OF_BITS);
+
+ set = drvdata->dsb->edge_ctrl_mask[reg];
+ if (val)
+ set = set | BIT(bit);
minor nit:
set |= ..
+ else
+ set = set & ~BIT(bit);
set &= .. ?
+ drvdata->dsb->edge_ctrl_mask[reg] = set;
+ }
+ spin_unlock(&drvdata->spinlock);
+ return size;
+}
+static DEVICE_ATTR_RW(dsb_edge_ctrl_mask);
+
static ssize_t dsb_trig_type_show(struct device *dev,
struct device_attribute *attr,
char *buf)
@@ -359,6 +485,8 @@ static ssize_t dsb_trig_ts_store(struct device *dev,
static DEVICE_ATTR_RW(dsb_trig_ts);
static struct attribute *tpdm_dsb_attrs[] = {
&dev_attr_dsb_mode.attr,
+ &dev_attr_dsb_edge_ctrl.attr,
+ &dev_attr_dsb_edge_ctrl_mask.attr,
&dev_attr_dsb_trig_ts.attr,
&dev_attr_dsb_trig_type.attr,
NULL,
diff --git a/drivers/hwtracing/coresight/coresight-tpdm.h b/drivers/hwtracing/coresight/coresight-tpdm.h
index 4d57488..ed03c68 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.h
+++ b/drivers/hwtracing/coresight/coresight-tpdm.h
@@ -12,6 +12,8 @@
/* DSB Subunit Registers */
#define TPDM_DSB_CR (0x780)
#define TPDM_DSB_TIER (0x784)
+#define TPDM_DSB_EDCR(n) (0x808 + (n * 4))
+#define TPDM_DSB_EDCMR(n) (0x848 + (n * 4))
/* Enable bit for DSB subunit */
#define TPDM_DSB_CR_ENA BIT(0)
@@ -28,6 +30,8 @@
#define TPDM_DSB_MODE_HPBYTESEL(val) BMVAL(val, 4, 8)
#define TPDM_MODE_ALL (0xFFFFFFF)
+#define NUM_OF_BITS 32
+
/* TPDM integration test registers */
#define TPDM_ITATBCNTRL (0xEF0)
#define TPDM_ITCNTRL (0xF00)
@@ -54,14 +58,21 @@
#define TPDM_PIDR0_DS_IMPDEF BIT(0)
#define TPDM_PIDR0_DS_DSB BIT(1)
+#define TPDM_DSB_MAX_EDCR 16 > +#define TPDM_DSB_MAX_LINES 256
A comment here would help :
e.g, EDCR has 2 bits for each lines. Thus we can
support upto (16 * 32) / 2 lines.
May be, even use that math above instead of hard coding 256 ?
And explain what each bits would do ?
+
/**
* struct dsb_dataset - specifics associated to dsb dataset
* @mode: DSB programming mode
+ * @edge_ctrl: Save value for edge control
+ * @edge_ctrl_mask: Save value for edge control mask
* @trig_ts: Enable/Disable trigger timestamp.
* @trig_type: Enable/Disable trigger type.
*/
struct dsb_dataset {
u32 mode;
+ u32 edge_ctrl[TPDM_DSB_MAX_EDCR];
+ u32 edge_ctrl_mask[TPDM_DSB_MAX_EDCR / 2];
Please use TPDM_DSB_MAX_EDCMR instead.
Suzuki
bool trig_ts;
bool trig_type;
};