When i debug mcp2518fd, some method to track registers is
needed. This easy debug interface will be ok.
For example,
read a register at 0xe00:
echo 0xe00 > can_get_reg
cat can_get_reg
write a register at 0xe00:
echo 0xe00,0x60 > can_set_reg
Signed-off-by: Su Yanjun <suyanjun218@xxxxxxxxx>
---
.../net/can/spi/mcp251xfd/mcp251xfd-core.c | 132 ++++++++++++++++++
1 file changed, 132 insertions(+)
diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
index ab8aad0a7594..d65abe5505d5 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
@@ -27,6 +27,131 @@
#define DEVICE_NAME "mcp251xfd"
+/* Add sysfs debug interface for easy to debug
+ *
+ * For example,
+ *
+ * - read a register
+ * echo 0xe00 > can_get_reg
+ * cat can_get_reg
+ *
+ * - write a register
+ * echo 0xe00,0x1 > can_set_reg
+ *
+ */
+static int reg_offset;
+
+static int __get_param(const char *buf, char *off, char *val)
+{
+ int len;
+
+ if (!buf || !off || !val)
+ return -EINVAL;
+
+ len = 0;
+ while (*buf != ',') {
+ *off++ = *buf++;
+ len++;
+
+ if (len >= 16)
+ return -EINVAL;
+ }
+
+ buf++;
+
+ *off = '\0';
+
+ len = 0;
+ while (*buf) {
+ *val++ = *buf++;
+ len++;
+
+ if (len >= 16)
+ return -EINVAL;
+ }
+
+ *val = '\0';
+
+ return 0;
+}
+
+static ssize_t can_get_reg_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ int err;
+ u32 val;
+ struct mcp251xfd_priv *priv;
+
+ priv = dev_get_drvdata(dev);
+
+ err = regmap_read(priv->map_reg, reg_offset, &val);
+ if (err)
+ return 0;
+
+ return sprintf(buf, "reg = 0x%08x, val = 0x%08x\n", reg_offset, val);
+}
+
+static ssize_t can_get_reg_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t len)
+{
+ u32 off;
+
+ reg_offset = 0;
+
+ if (kstrtouint(buf, 0, &off) || (off % 4))
+ return -EINVAL;
+
+ reg_offset = off;
+
+ return len;
+}
+
+static ssize_t can_set_reg_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return 0;
+}
+
+static ssize_t can_set_reg_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t len)
+{
+ struct mcp251xfd_priv *priv;
+ u32 off, val;
+ int err;
+
+ char s1[16];
+ char s2[16];
+
+ if (__get_param(buf, s1, s2))
+ return -EINVAL;
+
+ if (kstrtouint(s1, 0, &off) || (off % 4))
+ return -EINVAL;
+
+ if (kstrtouint(s2, 0, &val))
+ return -EINVAL;
+
+ err = regmap_write(priv->map_reg, off, val);
+ if (err)
+ return -EINVAL;
+
+ return len;
+}
+
+static DEVICE_ATTR_RW(can_get_reg);
+static DEVICE_ATTR_RW(can_set_reg);
+
+static struct attribute *can_attributes[] = {
+ &dev_attr_can_get_reg.attr,
+ &dev_attr_can_set_reg.attr,
+ NULL
+};
+
+static const struct attribute_group can_group = {
+ .attrs = can_attributes,
+ NULL
+};
+
static const struct mcp251xfd_devtype_data mcp251xfd_devtype_data_mcp2517fd = {
.quirks = MCP251XFD_QUIRK_MAB_NO_WARN | MCP251XFD_QUIRK_CRC_REG |
MCP251XFD_QUIRK_CRC_RX | MCP251XFD_QUIRK_CRC_TX |
@@ -2944,6 +3069,12 @@ static int mcp251xfd_probe(struct spi_device *spi)
if (err)
goto out_free_candev;
+ err = sysfs_create_group(&spi->dev.kobj, &can_group);
+ if (err) {
+ netdev_err(priv->ndev, "Create can group fail.\n");
+ goto out_free_candev;
+ }
+
err = can_rx_offload_add_manual(ndev, &priv->offload,
MCP251XFD_NAPI_WEIGHT);
if (err)
@@ -2972,6 +3103,7 @@ static int mcp251xfd_remove(struct spi_device *spi)
mcp251xfd_unregister(priv);
spi->max_speed_hz = priv->spi_max_speed_hz_orig;
free_candev(ndev);
+ sysfs_remove_group(&spi->dev.kobj, &can_group);
return 0;
}
--
2.25.1
