Subject: [PATCH V2 4/5] stmmac: add ipq806x glue layer

From: Mathieu Olivari <[email-masked]>
Date: Wed, 27 May 2015 11:02:49 -0700

The ethernet controller available in IPQ806x is a Synopsys DesignWare
Gigabit MAC IP core, already supported by the stmmac driver.

This glue layer implements some platform specific settings required to
get the controller working on an IPQ806x based platform.

Signed-off-by: Mathieu Olivari <[email-masked]>
---

Notes:
    v2:
     *fix MODULE_LICENSE to "Dual BSD/GPL" as this file is using ISC license

 drivers/net/ethernet/stmicro/stmmac/Kconfig        |  14 +
 drivers/net/ethernet/stmicro/stmmac/Makefile       |   1 +
 .../net/ethernet/stmicro/stmmac/dwmac-ipq806x.c    | 365 +++++++++++++++++++++
 3 files changed, 380 insertions(+)
 create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c

diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
index 731e045..cec147d 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
+++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
@@ -16,6 +16,7 @@ if STMMAC_ETH
 config STMMAC_PLATFORM
 	tristate "STMMAC Platform bus support"
 	depends on STMMAC_ETH
+	select MFD_SYSCON
 	default y
 	---help---
 	  This selects the platform specific bus support for the stmmac driver.
@@ -36,6 +37,19 @@ config DWMAC_GENERIC
 	  platform specific code to function or is using platform
 	  data for setup.
 
+config DWMAC_IPQ806X
+	tristate "QCA IPQ806x DWMAC support"
+	default ARCH_QCOM
+	depends on OF
+	select MFD_SYSCON
+	help
+	  Support for QCA IPQ806X DWMAC Ethernet.
+
+	  This selects the IPQ806x SoC glue layer support for the stmmac
+	  device driver. This driver does not use any of the hardware
+	  acceleration features available on this SoC. Network devices
+	  will behave like standard non-accelerated ethernet interfaces.
+
 config DWMAC_LPC18XX
 	tristate "NXP LPC18xx/43xx DWMAC support"
 	default ARCH_LPC18XX
diff --git a/drivers/net/ethernet/stmicro/stmmac/Makefile b/drivers/net/ethernet/stmicro/stmmac/Makefile
index 92e714a..b390161 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Makefile
+++ b/drivers/net/ethernet/stmicro/stmmac/Makefile
@@ -6,6 +6,7 @@ stmmac-objs:= stmmac_main.o stmmac_ethtool.o stmmac_mdio.o ring_mode.o	\
 
 # Ordering matters. Generic driver must be last.
 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
 obj-$(CONFIG_DWMAC_ROCKCHIP)	+= dwmac-rk.o
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c
new file mode 100644
index 0000000..7e3129e
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-ipq806x.c
@@ -0,0 +1,365 @@
+/*
+ * Qualcomm Atheros IPQ806x GMAC glue layer
+ *
+ * Copyright (C) 2015 The Linux Foundation
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/phy.h>
+#include <linux/regmap.h>
+#include <linux/clk.h>
+#include <linux/reset.h>
+#include <linux/of_net.h>
+#include <linux/mfd/syscon.h>
+#include <linux/stmmac.h>
+#include <linux/of_mdio.h>
+#include <linux/module.h>
+
+#include "stmmac_platform.h"
+
+#define NSS_COMMON_CLK_GATE			0x8
+#define NSS_COMMON_CLK_GATE_PTP_EN(x)		BIT(0x10 + x)
+#define NSS_COMMON_CLK_GATE_RGMII_RX_EN(x)	BIT(0x9 + (x * 2))
+#define NSS_COMMON_CLK_GATE_RGMII_TX_EN(x)	BIT(0x8 + (x * 2))
+#define NSS_COMMON_CLK_GATE_GMII_RX_EN(x)	BIT(0x4 + x)
+#define NSS_COMMON_CLK_GATE_GMII_TX_EN(x)	BIT(0x0 + x)
+
+#define NSS_COMMON_CLK_DIV0			0xC
+#define NSS_COMMON_CLK_DIV_OFFSET(x)		(x * 8)
+#define NSS_COMMON_CLK_DIV_MASK			0x7f
+
+#define NSS_COMMON_CLK_SRC_CTRL			0x14
+#define NSS_COMMON_CLK_SRC_CTRL_OFFSET(x)	(1 << x)
+/* Mode is coded on 1 bit but is different depending on the MAC ID:
+ * MAC0: QSGMII=0 RGMII=1
+ * MAC1: QSGMII=0 SGMII=0 RGMII=1
+ * MAC2 & MAC3: QSGMII=0 SGMII=1
+ */
+#define NSS_COMMON_CLK_SRC_CTRL_RGMII(x)	1
+#define NSS_COMMON_CLK_SRC_CTRL_SGMII(x)	((x >= 2) ? 1 : 0)
+
+#define NSS_COMMON_MACSEC_CTL			0x28
+#define NSS_COMMON_MACSEC_CTL_EXT_BYPASS_EN(x)	(1 << x)
+
+#define NSS_COMMON_GMAC_CTL(x)			(0x30 + (x * 4))
+#define NSS_COMMON_GMAC_CTL_CSYS_REQ		BIT(19)
+#define NSS_COMMON_GMAC_CTL_PHY_IFACE_SEL	BIT(16)
+#define NSS_COMMON_GMAC_CTL_IFG_LIMIT_OFFSET	8
+#define NSS_COMMON_GMAC_CTL_IFG_OFFSET		0
+#define NSS_COMMON_GMAC_CTL_IFG_MASK		0x3f
+
+#define NSS_COMMON_CLK_DIV_RGMII_1000		1
+#define NSS_COMMON_CLK_DIV_RGMII_100		9
+#define NSS_COMMON_CLK_DIV_RGMII_10		99
+#define NSS_COMMON_CLK_DIV_SGMII_1000		0
+#define NSS_COMMON_CLK_DIV_SGMII_100		4
+#define NSS_COMMON_CLK_DIV_SGMII_10		49
+
+#define QSGMII_PCS_MODE_CTL			0x68
+#define QSGMII_PCS_MODE_CTL_AUTONEG_EN(x)	BIT((x * 8) + 7)
+
+#define QSGMII_PCS_CAL_LCKDT_CTL		0x120
+#define QSGMII_PCS_CAL_LCKDT_CTL_RST		BIT(19)
+
+/* Only GMAC1/2/3 support SGMII and their CTL register are not contiguous */
+#define QSGMII_PHY_SGMII_CTL(x)			((x == 1) ? 0x134 : \
+						 (0x13c + (4 * (x - 2))))
+#define QSGMII_PHY_CDR_EN			BIT(0)
+#define QSGMII_PHY_RX_FRONT_EN			BIT(1)
+#define QSGMII_PHY_RX_SIGNAL_DETECT_EN		BIT(2)
+#define QSGMII_PHY_TX_DRIVER_EN			BIT(3)
+#define QSGMII_PHY_QSGMII_EN			BIT(7)
+#define QSGMII_PHY_PHASE_LOOP_GAIN_OFFSET	12
+#define QSGMII_PHY_PHASE_LOOP_GAIN_MASK		0x7
+#define QSGMII_PHY_RX_DC_BIAS_OFFSET		18
+#define QSGMII_PHY_RX_DC_BIAS_MASK		0x3
+#define QSGMII_PHY_RX_INPUT_EQU_OFFSET		20
+#define QSGMII_PHY_RX_INPUT_EQU_MASK		0x3
+#define QSGMII_PHY_CDR_PI_SLEW_OFFSET		22
+#define QSGMII_PHY_CDR_PI_SLEW_MASK		0x3
+#define QSGMII_PHY_TX_DRV_AMP_OFFSET		28
+#define QSGMII_PHY_TX_DRV_AMP_MASK		0xf
+
+struct ipq806x_gmac {
+	struct platform_device *pdev;
+	struct regmap *nss_common;
+	struct regmap *qsgmii_csr;
+	uint32_t id;
+	struct clk *core_clk;
+	phy_interface_t phy_mode;
+};
+
+static int get_clk_div_sgmii(struct ipq806x_gmac *gmac, unsigned int speed)
+{
+	struct device *dev = &gmac->pdev->dev;
+	int div;
+
+	switch (speed) {
+	case SPEED_1000:
+		div = NSS_COMMON_CLK_DIV_SGMII_1000;
+		break;
+
+	case SPEED_100:
+		div = NSS_COMMON_CLK_DIV_SGMII_100;
+		break;
+
+	case SPEED_10:
+		div = NSS_COMMON_CLK_DIV_SGMII_10;
+		break;
+
+	default:
+		dev_err(dev, "Speed %dMbps not supported in SGMII\n", speed);
+		return -EINVAL;
+	}
+
+	return div;
+}
+
+static int get_clk_div_rgmii(struct ipq806x_gmac *gmac, unsigned int speed)
+{
+	struct device *dev = &gmac->pdev->dev;
+	int div;
+
+	switch (speed) {
+	case SPEED_1000:
+		div = NSS_COMMON_CLK_DIV_RGMII_1000;
+		break;
+
+	case SPEED_100:
+		div = NSS_COMMON_CLK_DIV_RGMII_100;
+		break;
+
+	case SPEED_10:
+		div = NSS_COMMON_CLK_DIV_RGMII_10;
+		break;
+
+	default:
+		dev_err(dev, "Speed %dMbps not supported in RGMII\n", speed);
+		return -EINVAL;
+	}
+
+	return div;
+}
+
+static int ipq806x_gmac_set_speed(struct ipq806x_gmac *gmac, unsigned int speed)
+{
+	uint32_t clk_bits, val;
+	int div;
+
+	switch (gmac->phy_mode) {
+	case PHY_INTERFACE_MODE_RGMII:
+		div = get_clk_div_rgmii(gmac, speed);
+		clk_bits = NSS_COMMON_CLK_GATE_RGMII_RX_EN(gmac->id) |
+			   NSS_COMMON_CLK_GATE_RGMII_TX_EN(gmac->id);
+		break;
+
+	case PHY_INTERFACE_MODE_SGMII:
+		div = get_clk_div_sgmii(gmac, speed);
+		clk_bits = NSS_COMMON_CLK_GATE_GMII_RX_EN(gmac->id) |
+			   NSS_COMMON_CLK_GATE_GMII_TX_EN(gmac->id);
+		break;
+
+	default:
+		dev_err(&gmac->pdev->dev, "Unsupported PHY mode: \"%s\"\n",
+			phy_modes(gmac->phy_mode));
+		return -EINVAL;
+	}
+
+	/* Disable the clocks */
+	regmap_read(gmac->nss_common, NSS_COMMON_CLK_GATE, &val);
+	val &= ~clk_bits;
+	regmap_write(gmac->nss_common, NSS_COMMON_CLK_GATE, val);
+
+	/* Set the divider */
+	regmap_read(gmac->nss_common, NSS_COMMON_CLK_DIV0, &val);
+	val &= ~(NSS_COMMON_CLK_DIV_MASK
+		 << NSS_COMMON_CLK_DIV_OFFSET(gmac->id));
+	val |= div << NSS_COMMON_CLK_DIV_OFFSET(gmac->id);
+	regmap_write(gmac->nss_common, NSS_COMMON_CLK_DIV0, val);
+
+	/* Enable the clock back */
+	regmap_read(gmac->nss_common, NSS_COMMON_CLK_GATE, &val);
+	val |= clk_bits;
+	regmap_write(gmac->nss_common, NSS_COMMON_CLK_GATE, val);
+
+	return 0;
+}
+
+static void *ipq806x_gmac_of_parse(struct ipq806x_gmac *gmac)
+{
+	struct device *dev = &gmac->pdev->dev;
+
+	gmac->phy_mode = of_get_phy_mode(dev->of_node);
+	if (gmac->phy_mode < 0) {
+		dev_err(dev, "missing phy mode property\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (of_property_read_u32(dev->of_node, "qcom,id", &gmac->id) < 0) {
+		dev_err(dev, "missing qcom id property\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	/* The GMACs are called 1 to 4 in the documentation, but to simplify the
+	 * code and keep it consistent with the Linux convention, we'll number
+	 * them from 0 to 3 here.
+	 */
+	if (gmac->id < 0 || gmac->id > 3) {
+		dev_err(dev, "invalid gmac id\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	gmac->core_clk = devm_clk_get(dev, "stmmaceth");
+	if (IS_ERR(gmac->core_clk)) {
+		dev_err(dev, "missing stmmaceth clk property\n");
+		return gmac->core_clk;
+	}
+	clk_set_rate(gmac->core_clk, 266000000);
+
+	/* Setup the register map for the nss common registers */
+	gmac->nss_common = syscon_regmap_lookup_by_phandle(dev->of_node,
+							   "qcom,nss-common");
+	if (IS_ERR(gmac->nss_common)) {
+		dev_err(dev, "missing nss-common node\n");
+		return gmac->nss_common;
+	}
+
+	/* Setup the register map for the qsgmii csr registers */
+	gmac->qsgmii_csr = syscon_regmap_lookup_by_phandle(dev->of_node,
+							   "qcom,qsgmii-csr");
+	if (IS_ERR(gmac->qsgmii_csr)) {
+		dev_err(dev, "missing qsgmii-csr node\n");
+		return gmac->qsgmii_csr;
+	}
+
+	return NULL;
+}
+
+static void *ipq806x_gmac_setup(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct ipq806x_gmac *gmac;
+	int val;
+	void *err;
+
+	gmac = devm_kzalloc(dev, sizeof(*gmac), GFP_KERNEL);
+	if (!gmac)
+		return ERR_PTR(-ENOMEM);
+
+	gmac->pdev = pdev;
+
+	err = ipq806x_gmac_of_parse(gmac);
+	if (err) {
+		dev_err(dev, "device tree parsing error\n");
+		return err;
+	}
+
+	regmap_write(gmac->qsgmii_csr, QSGMII_PCS_CAL_LCKDT_CTL,
+		     QSGMII_PCS_CAL_LCKDT_CTL_RST);
+
+	/* Inter frame gap is set to 12 */
+	val = 12 << NSS_COMMON_GMAC_CTL_IFG_OFFSET |
+	      12 << NSS_COMMON_GMAC_CTL_IFG_LIMIT_OFFSET;
+	/* We also initiate an AXI low power exit request */
+	val |= NSS_COMMON_GMAC_CTL_CSYS_REQ;
+	switch (gmac->phy_mode) {
+	case PHY_INTERFACE_MODE_RGMII:
+		val |= NSS_COMMON_GMAC_CTL_PHY_IFACE_SEL;
+		break;
+	case PHY_INTERFACE_MODE_SGMII:
+		val &= ~NSS_COMMON_GMAC_CTL_PHY_IFACE_SEL;
+		break;
+	default:
+		dev_err(&pdev->dev, "Unsupported PHY mode: \"%s\"\n",
+			phy_modes(gmac->phy_mode));
+		return NULL;
+	}
+	regmap_write(gmac->nss_common, NSS_COMMON_GMAC_CTL(gmac->id), val);
+
+	/* Configure the clock src according to the mode */
+	regmap_read(gmac->nss_common, NSS_COMMON_CLK_SRC_CTRL, &val);
+	val &= ~NSS_COMMON_CLK_SRC_CTRL_OFFSET(gmac->id);
+	switch (gmac->phy_mode) {
+	case PHY_INTERFACE_MODE_RGMII:
+		val |= NSS_COMMON_CLK_SRC_CTRL_RGMII(gmac->id) <<
+			NSS_COMMON_CLK_SRC_CTRL_OFFSET(gmac->id);
+		break;
+	case PHY_INTERFACE_MODE_SGMII:
+		val |= NSS_COMMON_CLK_SRC_CTRL_SGMII(gmac->id) <<
+			NSS_COMMON_CLK_SRC_CTRL_OFFSET(gmac->id);
+		break;
+	default:
+		dev_err(&pdev->dev, "Unsupported PHY mode: \"%s\"\n",
+			phy_modes(gmac->phy_mode));
+		return NULL;
+	}
+	regmap_write(gmac->nss_common, NSS_COMMON_CLK_SRC_CTRL, val);
+
+	/* Enable PTP clock */
+	regmap_read(gmac->nss_common, NSS_COMMON_CLK_GATE, &val);
+	val |= NSS_COMMON_CLK_GATE_PTP_EN(gmac->id);
+	regmap_write(gmac->nss_common, NSS_COMMON_CLK_GATE, val);
+
+	if (gmac->phy_mode == PHY_INTERFACE_MODE_SGMII) {
+		regmap_write(gmac->qsgmii_csr, QSGMII_PHY_SGMII_CTL(gmac->id),
+			     QSGMII_PHY_CDR_EN |
+			     QSGMII_PHY_RX_FRONT_EN |
+			     QSGMII_PHY_RX_SIGNAL_DETECT_EN |
+			     QSGMII_PHY_TX_DRIVER_EN |
+			     QSGMII_PHY_QSGMII_EN |
+			     0x4 << QSGMII_PHY_PHASE_LOOP_GAIN_OFFSET |
+			     0x3 << QSGMII_PHY_RX_DC_BIAS_OFFSET |
+			     0x1 << QSGMII_PHY_RX_INPUT_EQU_OFFSET |
+			     0x2 << QSGMII_PHY_CDR_PI_SLEW_OFFSET |
+			     0xC << QSGMII_PHY_TX_DRV_AMP_OFFSET);
+	}
+
+	return gmac;
+}
+
+static void ipq806x_gmac_fix_mac_speed(void *priv, unsigned int speed)
+{
+	struct ipq806x_gmac *gmac = priv;
+
+	ipq806x_gmac_set_speed(gmac, speed);
+}
+
+static const struct stmmac_of_data ipq806x_gmac_data = {
+	.has_gmac	= 1,
+	.setup		= ipq806x_gmac_setup,
+	.fix_mac_speed	= ipq806x_gmac_fix_mac_speed,
+};
+
+static const struct of_device_id ipq806x_gmac_dwmac_match[] = {
+	{ .compatible = "qcom,ipq806x-gmac", .data = &ipq806x_gmac_data },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ipq806x_gmac_dwmac_match);
+
+static struct platform_driver ipq806x_gmac_dwmac_driver = {
+	.probe = stmmac_pltfr_probe,
+	.remove = stmmac_pltfr_remove,
+	.driver = {
+		.name		= "ipq806x-gmac-dwmac",
+		.pm		= &stmmac_pltfr_pm_ops,
+		.of_match_table	= ipq806x_gmac_dwmac_match,
+	},
+};
+module_platform_driver(ipq806x_gmac_dwmac_driver);
+
+MODULE_AUTHOR("Mathieu Olivari <[email-masked]>");
+MODULE_DESCRIPTION("Qualcomm Atheros IPQ806x DWMAC specific glue layer");
+MODULE_LICENSE("Dual BSD/GPL");
-- 
2.1.4

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