[PATCH] net: stmmac: Add OXNAS Glue Driver

[Neil Armstrong <narmstrong@baylibre.com>]

Add Synopsys Designware MAC Glue layer for the Oxford Semiconductor OX820.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 .../devicetree/bindings/net/oxnas-dwmac.txt        |  44 +++++
 drivers/net/ethernet/stmicro/stmmac/Kconfig        |  11 ++
 drivers/net/ethernet/stmicro/stmmac/Makefile       |   1 +
 drivers/net/ethernet/stmicro/stmmac/dwmac-oxnas.c  | 219 +++++++++++++++++++++
 4 files changed, 275 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/oxnas-dwmac.txt
 create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-oxnas.c

Changes since RFC at https://patchwork.kernel.org/patch/9387257 :
 - Drop init/exit callbacks
 - Implement proper remove and PM callback
 - Call init from probe
 - Disable/Unprepare clock if stmmac probe fails

diff --git a/Documentation/devicetree/bindings/net/oxnas-dwmac.txt b/Documentation/devicetree/bindings/net/oxnas-dwmac.txt
new file mode 100644
index 0000000..5d2696c
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/oxnas-dwmac.txt
@@ -0,0 +1,44 @@
+* Oxford Semiconductor OXNAS DWMAC Ethernet controller
+
+The device inherits all the properties of the dwmac/stmmac devices
+described in the file stmmac.txt in the current directory with the
+following changes.
+
+Required properties on all platforms:
+
+- compatible:	Depending on the platform this should be one of:
+			- "oxsemi,ox820-dwmac"
+		Additionally "snps,dwmac" and any applicable more
+		detailed version number described in net/stmmac.txt
+		should be used.
+
+- reg:	The first register range should be the one of the DWMAC
+	controller.
+
+- clocks: Should contain phandles to the following clocks
+- clock-names:	Should contain the following:
+		- "stmmaceth" - see stmmac.txt
+		- "gmac" - peripheral gate clock
+
+- oxsemi,sys-ctrl: a phandle to the system controller syscon node
+
+Example :
+
+etha: ethernet@40400000 {
+	compatible = "oxsemi,ox820-dwmac", "snps,dwmac";
+	reg = <0x40400000 0x2000>;
+	interrupts = <GIC_SPI 8 IRQ_TYPE_LEVEL_HIGH>,
+		     <GIC_SPI 17 IRQ_TYPE_LEVEL_HIGH>;
+	interrupt-names = "macirq", "eth_wake_irq";
+	mac-address = [000000000000]; /* Filled in by U-Boot */
+	phy-mode = "rgmii";
+
+	clocks = <&stdclk CLK_820_ETHA>, <&gmacclk>;
+	clock-names = "gmac", "stmmaceth";
+	resets = <&reset RESET_MAC>;
+
+	/* Regmap for sys registers */
+	oxsemi,sys-ctrl = <&sys>;
+
+	status = "disabled";
+};
diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
index 3818c5e..27ed913 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
+++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
@@ -62,6 +62,7 @@ config DWMAC_MESON
 	tristate "Amlogic Meson dwmac support"
 	default ARCH_MESON
 	depends on OF && COMMON_CLK && (ARCH_MESON || COMPILE_TEST)
+	select MFD_SYSCON
 	help
 	  Support for Ethernet controller on Amlogic Meson SoCs.
 
@@ -69,6 +70,16 @@ config DWMAC_MESON
 	  the stmmac device driver. This driver is used for Meson6,
 	  Meson8, Meson8b and GXBB SoCs.
 
+config DWMAC_OXNAS
+	tristate "Oxford Semiconductor OXNAS dwmac support"
+	default ARCH_OXNAS
+	depends on OF && COMMON_CLK && (ARCH_OXNAS || COMPILE_TEST)
+	help
+	  Support for Ethernet controller on Oxford Semiconductor OXNAS SoCs.
+
+	  This selects the Oxford Semiconductor OXNASSoC glue layer support for
+	  the stmmac device driver. This driver is used for OX820.
+
 config DWMAC_ROCKCHIP
 	tristate "Rockchip dwmac support"
 	default ARCH_ROCKCHIP
diff --git a/drivers/net/ethernet/stmicro/stmmac/Makefile b/drivers/net/ethernet/stmicro/stmmac/Makefile
index 5d6ece5..8f83a86 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Makefile
+++ b/drivers/net/ethernet/stmicro/stmmac/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_STMMAC_PLATFORM)	+= stmmac-platform.o
 obj-$(CONFIG_DWMAC_IPQ806X)	+= dwmac-ipq806x.o
 obj-$(CONFIG_DWMAC_LPC18XX)	+= dwmac-lpc18xx.o
 obj-$(CONFIG_DWMAC_MESON)	+= dwmac-meson.o dwmac-meson8b.o
+obj-$(CONFIG_DWMAC_OXNAS)	+= dwmac-oxnas.o
 obj-$(CONFIG_DWMAC_ROCKCHIP)	+= dwmac-rk.o
 obj-$(CONFIG_DWMAC_SOCFPGA)	+= dwmac-altr-socfpga.o
 obj-$(CONFIG_DWMAC_STI)		+= dwmac-sti.o
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-oxnas.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-oxnas.c
new file mode 100644
index 0000000..40fd845
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-oxnas.c
@@ -0,0 +1,219 @@
+/*
+ * Oxford Semiconductor OXNAS DWMAC glue layer
+ *
+ * Copyright (C) 2016 Neil Armstrong <narmstrong@baylibre.com>
+ * Copyright (C) 2014 Daniel Golle <daniel@makrotopia.org>
+ * Copyright (C) 2013 Ma Haijun <mahaijuns@gmail.com>
+ * Copyright (C) 2012 John Crispin <blogic@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+#include <linux/stmmac.h>
+
+#include "stmmac_platform.h"
+
+/* System Control regmap offsets */
+#define OXNAS_DWMAC_CTRL_REGOFFSET	0x78
+#define OXNAS_DWMAC_DELAY_REGOFFSET	0x100
+
+/* Control Register */
+#define DWMAC_CKEN_RX_IN        14
+#define DWMAC_CKEN_RXN_OUT      13
+#define DWMAC_CKEN_RX_OUT       12
+#define DWMAC_CKEN_TX_IN        10
+#define DWMAC_CKEN_TXN_OUT      9
+#define DWMAC_CKEN_TX_OUT       8
+#define DWMAC_RX_SOURCE         7
+#define DWMAC_TX_SOURCE         6
+#define DWMAC_LOW_TX_SOURCE     4
+#define DWMAC_AUTO_TX_SOURCE    3
+#define DWMAC_RGMII             2
+#define DWMAC_SIMPLE_MUX        1
+#define DWMAC_CKEN_GTX          0
+
+/* Delay register */
+#define DWMAC_TX_VARDELAY_SHIFT		0
+#define DWMAC_TXN_VARDELAY_SHIFT	8
+#define DWMAC_RX_VARDELAY_SHIFT		16
+#define DWMAC_RXN_VARDELAY_SHIFT	24
+#define DWMAC_TX_VARDELAY(d)		((d) << DWMAC_TX_VARDELAY_SHIFT)
+#define DWMAC_TXN_VARDELAY(d)		((d) << DWMAC_TXN_VARDELAY_SHIFT)
+#define DWMAC_RX_VARDELAY(d)		((d) << DWMAC_RX_VARDELAY_SHIFT)
+#define DWMAC_RXN_VARDELAY(d)		((d) << DWMAC_RXN_VARDELAY_SHIFT)
+
+struct oxnas_dwmac {
+	struct device	*dev;
+	struct clk	*clk;
+	struct regmap	*regmap;
+};
+
+static int oxnas_dwmac_init(struct oxnas_dwmac *dwmac)
+{
+	unsigned int value;
+	int ret;
+
+	/* Reset HW here before changing the glue configuration */
+	ret = device_reset(dwmac->dev);
+	if (ret)
+		return ret;
+
+	clk_prepare_enable(dwmac->clk);
+
+	ret = regmap_read(dwmac->regmap, OXNAS_DWMAC_CTRL_REGOFFSET, &value);
+	if (ret < 0)
+		return ret;
+
+	/* Enable GMII_GTXCLK to follow GMII_REFCLK, required for gigabit PHY */
+	value |= BIT(DWMAC_CKEN_GTX);
+	/* Use simple mux for 25/125 Mhz clock switching */
+	value |= BIT(DWMAC_SIMPLE_MUX);
+	/* set auto switch tx clock source */
+	value |= BIT(DWMAC_AUTO_TX_SOURCE);
+	/* enable tx & rx vardelay */
+	value |= BIT(DWMAC_CKEN_TX_OUT);
+	value |= BIT(DWMAC_CKEN_TXN_OUT);
+	value |= BIT(DWMAC_CKEN_TX_IN);
+	value |= BIT(DWMAC_CKEN_RX_OUT);
+	value |= BIT(DWMAC_CKEN_RXN_OUT);
+	value |= BIT(DWMAC_CKEN_RX_IN);
+	regmap_write(dwmac->regmap, OXNAS_DWMAC_CTRL_REGOFFSET, value);
+
+	/* set tx & rx vardelay */
+	value = DWMAC_TX_VARDELAY(4);
+	value |= DWMAC_TXN_VARDELAY(2);
+	value |= DWMAC_RX_VARDELAY(10);
+	value |= DWMAC_RXN_VARDELAY(8);
+	regmap_write(dwmac->regmap, OXNAS_DWMAC_DELAY_REGOFFSET, value);
+
+	return 0;
+}
+
+static int oxnas_dwmac_probe(struct platform_device *pdev)
+{
+	struct plat_stmmacenet_data *plat_dat;
+	struct stmmac_resources stmmac_res;
+	struct device_node *sysctrl;
+	struct oxnas_dwmac *dwmac;
+	int ret;
+
+	sysctrl = of_parse_phandle(pdev->dev.of_node, "oxsemi,sys-ctrl", 0);
+	if (!sysctrl) {
+		dev_err(&pdev->dev, "failed to get sys-ctrl node\n");
+		return -EINVAL;
+	}
+
+	ret = stmmac_get_platform_resources(pdev, &stmmac_res);
+	if (ret)
+		return ret;
+
+	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+	if (IS_ERR(plat_dat))
+		return PTR_ERR(plat_dat);
+
+	dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL);
+	if (!dwmac)
+		return -ENOMEM;
+
+	dwmac->dev = &pdev->dev;
+	plat_dat->bsp_priv = dwmac;
+
+	dwmac->regmap = syscon_node_to_regmap(sysctrl);
+	if (IS_ERR(dwmac->regmap)) {
+		dev_err(&pdev->dev, "failed to have sysctrl regmap\n");
+		return PTR_ERR(dwmac->regmap);
+	}
+
+	dwmac->clk = devm_clk_get(&pdev->dev, "gmac");
+	if (IS_ERR(dwmac->clk))
+		return PTR_ERR(dwmac->clk);
+
+	ret = oxnas_dwmac_init(dwmac);
+	if (ret)
+		return ret;
+
+	ret = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
+	if (ret)
+		clk_disable_unprepare(dwmac->clk);
+
+	return ret;
+}
+
+static int oxnas_dwmac_remove(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+	struct stmmac_priv *priv = netdev_priv(ndev);
+	struct oxnas_dwmac *dwmac = priv->plat->bsp_priv;
+	int ret = stmmac_dvr_remove(&pdev->dev);
+
+	clk_disable_unprepare(dwmac->clk);
+
+	return ret;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int oxnas_dwmac_suspend(struct device *dev)
+{
+	struct net_device *ndev = dev_get_drvdata(dev);
+	struct stmmac_priv *priv = netdev_priv(ndev);
+	struct oxnas_dwmac *dwmac = priv->plat->bsp_priv;
+	int ret;
+
+	ret = stmmac_suspend(dev);
+	clk_disable_unprepare(dwmac->clk);
+
+	return ret;
+}
+
+static int oxnas_dwmac_resume(struct device *dev)
+{
+	struct net_device *ndev = dev_get_drvdata(dev);
+	struct stmmac_priv *priv = netdev_priv(ndev);
+	struct oxnas_dwmac *dwmac = priv->plat->bsp_priv;
+	int ret;
+
+	ret = oxnas_dwmac_init(dwmac);
+	if (ret)
+		return ret;
+
+	ret = stmmac_resume(dev);
+
+	return ret;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static SIMPLE_DEV_PM_OPS(oxnas_dwmac_pm_ops,
+	oxnas_dwmac_suspend, oxnas_dwmac_resume);
+
+static const struct of_device_id oxnas_dwmac_match[] = {
+	{ .compatible = "oxsemi,ox820-dwmac" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, oxnas_dwmac_match);
+
+static struct platform_driver oxnas_dwmac_driver = {
+	.probe  = oxnas_dwmac_probe,
+	.remove = oxnas_dwmac_remove,
+	.driver = {
+		.name           = "oxnas-dwmac",
+		.pm		= &oxnas_dwmac_pm_ops,
+		.of_match_table = oxnas_dwmac_match,
+	},
+};
+module_platform_driver(oxnas_dwmac_driver);
+
+MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
+MODULE_DESCRIPTION("Oxford Semiconductor OXNAS DWMAC glue layer");
+MODULE_LICENSE("GPL v2");
-- 
2.7.0