amd-xgbe: Add I2C support for sideband communication

Add support to initialize and use the I2C controller within the hardware
in order to perform sideband communication, e.g. determine the SFP media
type that is installed.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 76 insertions, 0 deletions

diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-debugfs.c b/drivers/net/ethernet/amd/xgbe/xgbe-debugfs.c
index 951b5abd9be7..0c0140decbc2 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-debugfs.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-debugfs.c
@@ -376,6 +376,66 @@ static const struct file_operations xprop_reg_value_fops = {
 	.write = xprop_reg_value_write,
 };
 
+static ssize_t xi2c_reg_addr_read(struct file *filp, char __user *buffer,
+				  size_t count, loff_t *ppos)
+{
+	struct xgbe_prv_data *pdata = filp->private_data;
+
+	return xgbe_common_read(buffer, count, ppos, pdata->debugfs_xi2c_reg);
+}
+
+static ssize_t xi2c_reg_addr_write(struct file *filp,
+				   const char __user *buffer,
+				   size_t count, loff_t *ppos)
+{
+	struct xgbe_prv_data *pdata = filp->private_data;
+
+	return xgbe_common_write(buffer, count, ppos,
+				 &pdata->debugfs_xi2c_reg);
+}
+
+static ssize_t xi2c_reg_value_read(struct file *filp, char __user *buffer,
+				   size_t count, loff_t *ppos)
+{
+	struct xgbe_prv_data *pdata = filp->private_data;
+	unsigned int value;
+
+	value = XI2C_IOREAD(pdata, pdata->debugfs_xi2c_reg);
+
+	return xgbe_common_read(buffer, count, ppos, value);
+}
+
+static ssize_t xi2c_reg_value_write(struct file *filp,
+				    const char __user *buffer,
+				    size_t count, loff_t *ppos)
+{
+	struct xgbe_prv_data *pdata = filp->private_data;
+	unsigned int value;
+	ssize_t len;
+
+	len = xgbe_common_write(buffer, count, ppos, &value);
+	if (len < 0)
+		return len;
+
+	XI2C_IOWRITE(pdata, pdata->debugfs_xi2c_reg, value);
+
+	return len;
+}
+
+static const struct file_operations xi2c_reg_addr_fops = {
+	.owner = THIS_MODULE,
+	.open = simple_open,
+	.read =  xi2c_reg_addr_read,
+	.write = xi2c_reg_addr_write,
+};
+
+static const struct file_operations xi2c_reg_value_fops = {
+	.owner = THIS_MODULE,
+	.open = simple_open,
+	.read =  xi2c_reg_value_read,
+	.write = xi2c_reg_value_write,
+};
+
 void xgbe_debugfs_init(struct xgbe_prv_data *pdata)
 {
 	struct dentry *pfile;
@@ -443,6 +503,22 @@ void xgbe_debugfs_init(struct xgbe_prv_data *pdata)
 				   "debugfs_create_file failed\n");
 	}
 
+	if (pdata->xi2c_regs) {
+		pfile = debugfs_create_file("xi2c_register", 0600,
+					    pdata->xgbe_debugfs, pdata,
+					    &xi2c_reg_addr_fops);
+		if (!pfile)
+			netdev_err(pdata->netdev,
+				   "debugfs_create_file failed\n");
+
+		pfile = debugfs_create_file("xi2c_register_value", 0600,
+					    pdata->xgbe_debugfs, pdata,
+					    &xi2c_reg_value_fops);
+		if (!pfile)
+			netdev_err(pdata->netdev,
+				   "debugfs_create_file failed\n");
+	}
+
 	kfree(buf);
 }