Merge branch 'xgmac_mdio-preamble-suppression-and-custom-MDC-frequerncies'

Tobias Waldekranz says:

====================
net/fsl: xgmac_mdio: Preamble suppression and custom MDC frequencies

The first patch removes the docs for a binding that has never been
supported by the driver as far as I can see. This is a bit of a
mystery to me, maybe Freescale/NXP had/has support for it in an
internal version?

We then start working on the xgmac_mdio driver, converting the driver
to exclusively use managed resources, thereby simplifying the error
paths. Suggested by Andrew.

Preamble suppression is then added, followed by MDC frequency
customization. Neither code will change any bits if the corresponding
dt properties are not specified, so as to not trample on any setup
done by the bootloader, which boards might have relied on up to now.

Finally, we document the new bindings.

Tested on a T1023 based board.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/devicetree/bindings/net/fsl-fman.txt

@@ -388,14 +388,24 @@ PROPERTIES
 		Value type: <prop-encoded-array>
 		Definition: A standard property.
 
-- bus-frequency
+- clocks
+		Usage: optional
+		Value type: <phandle>
+		Definition: A reference to the input clock of the controller
+		from which the MDC frequency is derived.
+
+- clock-frequency
 		Usage: optional
 		Value type: <u32>
-		Definition: Specifies the external MDIO bus clock speed to
-		be used, if different from the standard 2.5 MHz.
-		This may be due to the standard speed being unsupported (e.g.
-		due to a hardware problem), or to advertise that all relevant
-		components in the system support a faster speed.
+		Definition: Specifies the external MDC frequency, in Hertz, to
+		be used. Requires that the input clock is specified in the
+		"clocks" property. See also: mdio.yaml.
+
+- suppress-preamble
+		Usage: optional
+		Value type: <boolean>
+		Definition: Disable generation of preamble bits. See also:
+		mdio.yaml.
 
 - interrupts
 		Usage: required for external MDIO

drivers/net/ethernet/freescale/xgmac_mdio.c

@@ -14,6 +14,7 @@
 
 #include <linux/acpi.h>
 #include <linux/acpi_mdio.h>
+#include <linux/clk.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/mdio.h>
@@ -36,9 +37,10 @@ struct tgec_mdio_controller {
 } __packed;
 
 #define MDIO_STAT_ENC		BIT(6)
-#define MDIO_STAT_CLKDIV(x)	(((x>>1) & 0xff) << 8)
+#define MDIO_STAT_CLKDIV(x)	(((x) & 0x1ff) << 7)
 #define MDIO_STAT_BSY		BIT(0)
 #define MDIO_STAT_RD_ER		BIT(1)
+#define MDIO_STAT_PRE_DIS	BIT(5)
 #define MDIO_CTL_DEV_ADDR(x) 	(x & 0x1f)
 #define MDIO_CTL_PORT_ADDR(x)	((x & 0x1f) << 5)
 #define MDIO_CTL_PRE_DIS	BIT(10)
@@ -50,6 +52,8 @@ struct tgec_mdio_controller {
 
 struct mdio_fsl_priv {
 	struct	tgec_mdio_controller __iomem *mdio_base;
+	struct	clk *enet_clk;
+	u32	mdc_freq;
 	bool	is_little_endian;
 	bool	has_a009885;
 	bool	has_a011043;
@@ -254,6 +258,50 @@ static int xgmac_mdio_read(struct mii_bus *bus, int phy_id, int regnum)
 	return ret;
 }
 
+static int xgmac_mdio_set_mdc_freq(struct mii_bus *bus)
+{
+	struct mdio_fsl_priv *priv = (struct mdio_fsl_priv *)bus->priv;
+	struct tgec_mdio_controller __iomem *regs = priv->mdio_base;
+	struct device *dev = bus->parent;
+	u32 mdio_stat, div;
+
+	if (device_property_read_u32(dev, "clock-frequency", &priv->mdc_freq))
+		return 0;
+
+	priv->enet_clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(priv->enet_clk)) {
+		dev_err(dev, "Input clock unknown, not changing MDC frequency");
+		return PTR_ERR(priv->enet_clk);
+	}
+
+	div = ((clk_get_rate(priv->enet_clk) / priv->mdc_freq) - 1) / 2;
+	if (div < 5 || div > 0x1ff) {
+		dev_err(dev, "Requested MDC frequecy is out of range, ignoring");
+		return -EINVAL;
+	}
+
+	mdio_stat = xgmac_read32(&regs->mdio_stat, priv->is_little_endian);
+	mdio_stat &= ~MDIO_STAT_CLKDIV(0x1ff);
+	mdio_stat |= MDIO_STAT_CLKDIV(div);
+	xgmac_write32(mdio_stat, &regs->mdio_stat, priv->is_little_endian);
+	return 0;
+}
+
+static void xgmac_mdio_set_suppress_preamble(struct mii_bus *bus)
+{
+	struct mdio_fsl_priv *priv = (struct mdio_fsl_priv *)bus->priv;
+	struct tgec_mdio_controller __iomem *regs = priv->mdio_base;
+	struct device *dev = bus->parent;
+	u32 mdio_stat;
+
+	if (!device_property_read_bool(dev, "suppress-preamble"))
+		return;
+
+	mdio_stat = xgmac_read32(&regs->mdio_stat, priv->is_little_endian);
+	mdio_stat |= MDIO_STAT_PRE_DIS;
+	xgmac_write32(mdio_stat, &regs->mdio_stat, priv->is_little_endian);
+}
+
 static int xgmac_mdio_probe(struct platform_device *pdev)
 {
 	struct fwnode_handle *fwnode;
@@ -273,7 +321,7 @@ static int xgmac_mdio_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	bus = mdiobus_alloc_size(sizeof(struct mdio_fsl_priv));
+	bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(struct mdio_fsl_priv));
 	if (!bus)
 		return -ENOMEM;
 
@@ -284,13 +332,11 @@ static int xgmac_mdio_probe(struct platform_device *pdev)
 	bus->probe_capabilities = MDIOBUS_C22_C45;
 	snprintf(bus->id, MII_BUS_ID_SIZE, "%pa", &res->start);
 
-	/* Set the PHY base address */
 	priv = bus->priv;
-	priv->mdio_base = ioremap(res->start, resource_size(res));
-	if (!priv->mdio_base) {
-		ret = -ENOMEM;
-		goto err_ioremap;
-	}
+	priv->mdio_base = devm_ioremap(&pdev->dev, res->start,
+				       resource_size(res));
+	if (IS_ERR(priv->mdio_base))
+		return PTR_ERR(priv->mdio_base);
 
 	/* For both ACPI and DT cases, endianness of MDIO controller
 	 * needs to be specified using "little-endian" property.
@@ -303,6 +349,12 @@ static int xgmac_mdio_probe(struct platform_device *pdev)
 	priv->has_a011043 = device_property_read_bool(&pdev->dev,
 						      "fsl,erratum-a011043");
 
+	xgmac_mdio_set_suppress_preamble(bus);
+
+	ret = xgmac_mdio_set_mdc_freq(bus);
+	if (ret)
+		return ret;
+
 	fwnode = pdev->dev.fwnode;
 	if (is_of_node(fwnode))
 		ret = of_mdiobus_register(bus, to_of_node(fwnode));
@@ -312,31 +364,11 @@ static int xgmac_mdio_probe(struct platform_device *pdev)
 		ret = -EINVAL;
 	if (ret) {
 		dev_err(&pdev->dev, "cannot register MDIO bus\n");
-		goto err_registration;
+		return ret;
 	}
 
 	platform_set_drvdata(pdev, bus);
 
-	return 0;
-
-err_registration:
-	iounmap(priv->mdio_base);
-
-err_ioremap:
-	mdiobus_free(bus);
-
-	return ret;
-}
-
-static int xgmac_mdio_remove(struct platform_device *pdev)
-{
-	struct mii_bus *bus = platform_get_drvdata(pdev);
-	struct mdio_fsl_priv *priv = bus->priv;
-
-	mdiobus_unregister(bus);
-	iounmap(priv->mdio_base);
-	mdiobus_free(bus);
-
 	return 0;
 }
 
@@ -364,7 +396,6 @@ static struct platform_driver xgmac_mdio_driver = {
 		.acpi_match_table = xgmac_acpi_match,
 	},
 	.probe = xgmac_mdio_probe,
-	.remove = xgmac_mdio_remove,
 };
 
 module_platform_driver(xgmac_mdio_driver);