[PATCH 1/2] net: dsa: mv88e6xxx: add write access to debugfs regs file

From: Vivien Didelot
Date: Wed Jul 08 2015 - 16:36:43 EST


Allow write access to the regs file in the debugfs interface, with the
following parameters:

echo <name> <reg> <value> > regs

Where "name" is the register name (as shown in the header row), "reg" is
the register address (as shown in the first column) and "value" is the
16-bit value. e.g.:

echo GLOBAL 1a 5550 > regs

Signed-off-by: Vivien Didelot <vivien.didelot@xxxxxxxxxxxxxxxxxxxx>
---
drivers/net/dsa/mv88e6xxx.c | 32 +++++++++++++++++++++++++++++++-
1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/mv88e6xxx.c b/drivers/net/dsa/mv88e6xxx.c
index 8c130c0..04e6eb6 100644
--- a/drivers/net/dsa/mv88e6xxx.c
+++ b/drivers/net/dsa/mv88e6xxx.c
@@ -1648,6 +1648,35 @@ static int mv88e6xxx_regs_show(struct seq_file *s, void *p)
return 0;
}

+static ssize_t mv88e6xxx_regs_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct seq_file *s = file->private_data;
+ struct dsa_switch *ds = s->private;
+ struct mv88e6xxx_priv_state *ps = ds_to_priv(ds);
+ char name[count];
+ unsigned int port, reg, val;
+ int ret;
+
+ ret = sscanf(buf, "%s %x %x", name, &reg, &val);
+ if (ret != 3)
+ return -EINVAL;
+
+ if (reg > 0x1f || val > 0xffff)
+ return -ERANGE;
+
+ if (strcasecmp(name, "GLOBAL") == 0)
+ ret = mv88e6xxx_reg_write(ds, REG_GLOBAL, reg, val);
+ else if (strcasecmp(name, "GLOBAL2") == 0)
+ ret = mv88e6xxx_reg_write(ds, REG_GLOBAL2, reg, val);
+ else if (kstrtouint(name, 10, &port) == 0 && port < ps->num_ports)
+ ret = mv88e6xxx_reg_write(ds, REG_PORT(port), reg, val);
+ else
+ return -EINVAL;
+
+ return ret < 0 ? ret : count;
+}
+
static int mv88e6xxx_regs_open(struct inode *inode, struct file *file)
{
return single_open(file, mv88e6xxx_regs_show, inode->i_private);
@@ -1656,6 +1685,7 @@ static int mv88e6xxx_regs_open(struct inode *inode, struct file *file)
static const struct file_operations mv88e6xxx_regs_fops = {
.open = mv88e6xxx_regs_open,
.read = seq_read,
+ .write = mv88e6xxx_regs_write,
.llseek = no_llseek,
.release = single_release,
.owner = THIS_MODULE,
@@ -1895,7 +1925,7 @@ int mv88e6xxx_setup_common(struct dsa_switch *ds)
ps->dbgfs = debugfs_create_dir(name, NULL);
kfree(name);

- debugfs_create_file("regs", S_IRUGO, ps->dbgfs, ds,
+ debugfs_create_file("regs", S_IRUGO | S_IWUSR, ps->dbgfs, ds,
&mv88e6xxx_regs_fops);

debugfs_create_file("atu", S_IRUGO, ps->dbgfs, ds,
--
2.4.5

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