[RFC PATCH 3/3] net: phy: at803x: add device tree binding
From: Michael Walle
Date: Wed Oct 30 2019 - 18:43:16 EST
Add support for configuring the CLK_25M pin as well as the RGMII I/O
voltage by the device tree.
Signed-off-by: Michael Walle <michael@xxxxxxxx>
---
drivers/net/phy/at803x.c | 156 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 154 insertions(+), 2 deletions(-)
diff --git a/drivers/net/phy/at803x.c b/drivers/net/phy/at803x.c
index 1eb5d4fb8925..32be4c72cf4b 100644
--- a/drivers/net/phy/at803x.c
+++ b/drivers/net/phy/at803x.c
@@ -13,7 +13,9 @@
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/of_gpio.h>
+#include <linux/bitfield.h>
#include <linux/gpio/consumer.h>
+#include <dt-bindings/net/atheros-at803x.h>
#define AT803X_SPECIFIC_STATUS 0x11
#define AT803X_SS_SPEED_MASK (3 << 14)
@@ -62,6 +64,37 @@
#define AT803X_DEBUG_REG_5 0x05
#define AT803X_DEBUG_TX_CLK_DLY_EN BIT(8)
+#define AT803X_DEBUG_REG_1F 0x1F
+#define AT803X_DEBUG_PLL_ON BIT(2)
+#define AT803X_DEBUG_RGMII_1V8 BIT(3)
+
+/* AT803x supports either the XTAL input pad, an internal PLL or the
+ * DSP as clock reference for the clock output pad. The XTAL reference
+ * is only used for 25 MHz output, all other frequencies need the PLL.
+ * The DSP as a clock reference is used in synchronous ethernet
+ * applications.
+ *
+ * By default the PLL is only enabled if there is a link. Otherwise
+ * the PHY will go into low power state and disabled the PLL. You can
+ * set the PLL_ON bit (see debug register 0x1f) to keep the PLL always
+ * enabled.
+ */
+#define AT803X_MMD7_CLK25M 0x8016
+#define AT803X_CLK_OUT_MASK GENMASK(4, 2)
+#define AT803X_CLK_OUT_25MHZ_XTAL 0
+#define AT803X_CLK_OUT_25MHZ_DSP 1
+#define AT803X_CLK_OUT_50MHZ_PLL 2
+#define AT803X_CLK_OUT_50MHZ_DSP 3
+#define AT803X_CLK_OUT_62_5MHZ_PLL 4
+#define AT803X_CLK_OUT_62_5MHZ_DSP 5
+#define AT803X_CLK_OUT_125MHZ_PLL 6
+#define AT803X_CLK_OUT_125MHZ_DSP 7
+
+#define AT803X_CLK_OUT_STRENGTH_MASK GENMASK(8, 7)
+#define AT803X_CLK_OUT_STRENGTH_FULL 0
+#define AT803X_CLK_OUT_STRENGTH_HALF 1
+#define AT803X_CLK_OUT_STRENGTH_QUARTER 2
+
#define ATH8030_PHY_ID 0x004dd076
#define ATH8031_PHY_ID 0x004dd074
#define ATH8035_PHY_ID 0x004dd072
@@ -73,6 +106,11 @@ MODULE_LICENSE("GPL");
struct at803x_priv {
bool phy_reset:1;
+ int flags;
+#define AT803X_KEEP_PLL_ENABLED BIT(0) /* don't turn off internal PLL */
+#define AT803X_RGMII_1V8 BIT(1) /* use 1.8V RGMII voltage */
+ u16 clk_25m_reg;
+ u16 clk_25m_mask;
};
struct at803x_context {
@@ -240,6 +278,74 @@ static int at803x_resume(struct phy_device *phydev)
return phy_modify(phydev, MII_BMCR, BMCR_PDOWN | BMCR_ISOLATE, 0);
}
+static int at803x_parse_dt(struct phy_device *phydev)
+{
+ struct device_node *node = phydev->mdio.dev.of_node;
+ struct at803x_priv *priv = phydev->priv;
+ u32 freq, strength;
+ unsigned int sel;
+ int ret;
+
+ if (!IS_ENABLED(CONFIG_OF_MDIO))
+ return 0;
+
+ if (!node)
+ return 0;
+
+ if (of_property_read_bool(node, "atheros,keep-pll-enabled"))
+ priv->flags |= AT803X_KEEP_PLL_ENABLED;
+
+ if (of_property_read_bool(node, "atheros,rgmii-io-1v8"))
+ priv->flags |= AT803X_RGMII_1V8;
+
+ ret = of_property_read_u32(node, "atheros,clk-out-frequency", &freq);
+ if (!ret) {
+ switch (freq) {
+ case 25000000:
+ sel = AT803X_CLK_OUT_25MHZ_XTAL;
+ break;
+ case 50000000:
+ sel = AT803X_CLK_OUT_50MHZ_PLL;
+ break;
+ case 62500000:
+ sel = AT803X_CLK_OUT_62_5MHZ_PLL;
+ break;
+ case 125000000:
+ sel = AT803X_CLK_OUT_125MHZ_PLL;
+ break;
+ default:
+ phydev_err(phydev,
+ "invalid atheros,clk-out-frequency\n");
+ return -EINVAL;
+ }
+
+ priv->clk_25m_reg |= FIELD_PREP(AT803X_CLK_OUT_MASK, sel);
+ priv->clk_25m_mask |= AT803X_CLK_OUT_MASK;
+ }
+
+ ret = of_property_read_u32(node, "atheros,clk-out-strength", &strength);
+ if (!ret) {
+ priv->clk_25m_mask |= AT803X_CLK_OUT_STRENGTH_MASK;
+ switch (strength) {
+ case AT803X_STRENGTH_FULL:
+ priv->clk_25m_reg |= AT803X_CLK_OUT_STRENGTH_FULL;
+ break;
+ case AT803X_STRENGTH_HALF:
+ priv->clk_25m_reg |= AT803X_CLK_OUT_STRENGTH_HALF;
+ break;
+ case AT803X_STRENGTH_QUARTER:
+ priv->clk_25m_reg |= AT803X_CLK_OUT_STRENGTH_QUARTER;
+ break;
+ default:
+ phydev_err(phydev,
+ "invalid atheros,clk-out-strength\n");
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
static int at803x_probe(struct phy_device *phydev)
{
struct device *dev = &phydev->mdio.dev;
@@ -251,11 +357,31 @@ static int at803x_probe(struct phy_device *phydev)
phydev->priv = priv;
- return 0;
+ return at803x_parse_dt(phydev);
+}
+
+static int at803x_clk_out_config(struct phy_device *phydev)
+{
+ struct at803x_priv *priv = phydev->priv;
+ int val;
+
+ if (!priv->clk_25m_mask)
+ return 0;
+
+ val = phy_read_mmd(phydev, MDIO_MMD_AN, AT803X_MMD7_CLK25M);
+ if (val < 0)
+ return val;
+
+ val &= ~priv->clk_25m_mask;
+ val |= priv->clk_25m_reg;
+
+ return phy_write_mmd(phydev, MDIO_MMD_AN, AT803X_MMD7_CLK25M, val);
}
static int at803x_config_init(struct phy_device *phydev)
{
+ struct at803x_priv *priv = phydev->priv;
+ u16 set = 0, clear = 0;
int ret;
/* The RX and TX delay default is:
@@ -276,8 +402,34 @@ static int at803x_config_init(struct phy_device *phydev)
ret = at803x_enable_tx_delay(phydev);
else
ret = at803x_disable_tx_delay(phydev);
+ if (ret < 0)
+ return ret;
- return ret;
+ ret = at803x_clk_out_config(phydev);
+ if (ret < 0)
+ return ret;
+
+ /* The default after hardware reset is:
+ * 1.5V RGMII I/O voltage
+ * PLL OFF (which means it is off if there is no link)
+ *
+ * After a soft reset, the values are retained.
+ */
+ if (priv->flags & AT803X_KEEP_PLL_ENABLED)
+ set |= AT803X_DEBUG_PLL_ON;
+ else
+ clear |= AT803X_DEBUG_PLL_ON;
+
+ if (priv->flags & AT803X_RGMII_1V8)
+ set |= AT803X_DEBUG_RGMII_1V8;
+ else
+ clear |= AT803X_DEBUG_RGMII_1V8;
+
+ ret = at803x_debug_reg_mask(phydev, AT803X_DEBUG_REG_1F, clear, set);
+ if (ret < 0)
+ return ret;
+
+ return 0;
}
static int at803x_ack_interrupt(struct phy_device *phydev)
--
2.20.1