Re: [net-next PATCH v5 03/14] net: dsa: qca8k: add support for sgmii falling edge

From: Florian Fainelli
Date: Sun Oct 10 2021 - 21:49:54 EST




On 10/10/2021 6:30 PM, Ansuel Smith wrote:
Add support for this in the qca8k driver. Also add support for SGMII
rx/tx clock falling edge. This is only present for pad0, pad5 and
pad6 have these bit reserved from Documentation. Add a comment that this
is hardcoded to PAD0 as qca8327/28/34/37 have an unique sgmii line and
setting falling in port0 applies to both configuration with sgmii used
for port0 or port6.

Signed-off-by: Matthew Hagan <mnhagan88@xxxxxxxxx>
Signed-off-by: Ansuel Smith <ansuelsmth@xxxxxxxxx>
---
drivers/net/dsa/qca8k.c | 57 +++++++++++++++++++++++++++++++++++++++++
drivers/net/dsa/qca8k.h | 4 +++
2 files changed, 61 insertions(+)

diff --git a/drivers/net/dsa/qca8k.c b/drivers/net/dsa/qca8k.c
index a892b897cd0d..e335a4cfcb75 100644
--- a/drivers/net/dsa/qca8k.c
+++ b/drivers/net/dsa/qca8k.c
@@ -977,6 +977,36 @@ qca8k_setup_mac_pwr_sel(struct qca8k_priv *priv)
return ret;
}
+static int
+qca8k_parse_port_config(struct qca8k_priv *priv)
+{
+ struct device_node *port_dn;
+ phy_interface_t mode;
+ struct dsa_port *dp;
+ int port;
+
+ /* We have 2 CPU port. Check them */
+ for (port = 0; port < QCA8K_NUM_PORTS; port++) {
+ /* Skip every other port */
+ if (port != 0 && port != 6)
+ continue;
+
+ dp = dsa_to_port(priv->ds, port);
+ port_dn = dp->dn;

You should probably have an:

if (!of_device_is_available(port_dn))
continue

to skip over ports being disabled, which could presumably happen in a sparsely populated switch for instance.

+
+ of_get_phy_mode(port_dn, &mode);

This function returns an error that you are not checking.

+ if (mode == PHY_INTERFACE_MODE_SGMII) {
+ if (of_property_read_bool(port_dn, "qca,sgmii-txclk-falling-edge"))
+ priv->sgmii_tx_clk_falling_edge = true;
+
+ if (of_property_read_bool(port_dn, "qca,sgmii-rxclk-falling-edge"))
+ priv->sgmii_rx_clk_falling_edge = true;
+ }
+ }
+
+ return 0;
+}
+
static int
qca8k_setup(struct dsa_switch *ds)
{
@@ -990,6 +1020,11 @@ qca8k_setup(struct dsa_switch *ds)
return -EINVAL;
}
+ /* Parse CPU port config to be later used in phy_link mac_config */
+ ret = qca8k_parse_port_config(priv);
+ if (ret)
+ return ret;
+
mutex_init(&priv->reg_mutex);
/* Start by setting up the register mapping */
@@ -1274,6 +1309,28 @@ qca8k_phylink_mac_config(struct dsa_switch *ds, int port, unsigned int mode,
}
qca8k_write(priv, QCA8K_REG_SGMII_CTRL, val);
+
+ /* For qca8327/qca8328/qca8334/qca8338 sgmii is unique and
+ * falling edge is set writing in the PORT0 PAD reg
+ */
+ if (priv->switch_id == QCA8K_ID_QCA8327 ||
+ priv->switch_id == QCA8K_ID_QCA8337)
+ reg = QCA8K_REG_PORT0_PAD_CTRL;
+
+ val = 0;
+
+ /* SGMII Clock phase configuration */
+ if (priv->sgmii_rx_clk_falling_edge)
+ val |= QCA8K_PORT0_PAD_SGMII_RXCLK_FALLING_EDGE;
+
+ if (priv->sgmii_tx_clk_falling_edge)
+ val |= QCA8K_PORT0_PAD_SGMII_TXCLK_FALLING_EDGE;
+
+ if (val)
+ ret = qca8k_rmw(priv, reg,
+ QCA8K_PORT0_PAD_SGMII_RXCLK_FALLING_EDGE |
+ QCA8K_PORT0_PAD_SGMII_TXCLK_FALLING_EDGE,
+ val);
break;
default:
dev_err(ds->dev, "xMII mode %s not supported for port %d\n",
diff --git a/drivers/net/dsa/qca8k.h b/drivers/net/dsa/qca8k.h
index fc7db94cc0c9..bc9c89dd7e71 100644
--- a/drivers/net/dsa/qca8k.h
+++ b/drivers/net/dsa/qca8k.h
@@ -35,6 +35,8 @@
#define QCA8K_MASK_CTRL_DEVICE_ID_MASK GENMASK(15, 8)
#define QCA8K_MASK_CTRL_DEVICE_ID(x) ((x) >> 8)
#define QCA8K_REG_PORT0_PAD_CTRL 0x004
+#define QCA8K_PORT0_PAD_SGMII_RXCLK_FALLING_EDGE BIT(19)
+#define QCA8K_PORT0_PAD_SGMII_TXCLK_FALLING_EDGE BIT(18)
#define QCA8K_REG_PORT5_PAD_CTRL 0x008
#define QCA8K_REG_PORT6_PAD_CTRL 0x00c
#define QCA8K_PORT_PAD_RGMII_EN BIT(26)
@@ -260,6 +262,8 @@ struct qca8k_priv {
u8 switch_revision;
u8 rgmii_tx_delay;
u8 rgmii_rx_delay;
+ bool sgmii_rx_clk_falling_edge;
+ bool sgmii_tx_clk_falling_edge;
bool legacy_phy_port_mapping;
struct regmap *regmap;
struct mii_bus *bus;


--
Florian