staging: mt7621-pci-phy: add new driver for phy part of mt7621-pci

Phy part of the pci for this SoC can be handled using a generic phy
driver. This commit extracts phy part of the mt7621-pci into a new
'mt7621-pci-phy' driver.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/Kconfig

@@ -104,6 +104,8 @@ source "drivers/staging/pi433/Kconfig"
 
 source "drivers/staging/mt7621-pci/Kconfig"
 
+source "drivers/staging/mt7621-pci-phy/Kconfig"
+
 source "drivers/staging/mt7621-pinctrl/Kconfig"
 
 source "drivers/staging/mt7621-spi/Kconfig"

drivers/staging/Makefile

@@ -42,6 +42,7 @@ obj-$(CONFIG_BCM2835_VCHIQ)	+= vc04_services/
 obj-$(CONFIG_DRM_VBOXVIDEO)	+= vboxvideo/
 obj-$(CONFIG_PI433)		+= pi433/
 obj-$(CONFIG_SOC_MT7621)	+= mt7621-pci/
+obj-$(CONFIG_SOC_MT7621)	+= mt7621-pci-phy/
 obj-$(CONFIG_SOC_MT7621)	+= mt7621-pinctrl/
 obj-$(CONFIG_SOC_MT7621)	+= mt7621-spi/
 obj-$(CONFIG_SOC_MT7621)	+= mt7621-dma/

drivers/staging/mt7621-pci-phy/Kconfig

@@ -0,0 +1,7 @@
+config PCI_MT7621_PHY
+	tristate "MediaTek MT7621 PCI PHY Driver"
+	depends on RALINK && OF
+	select GENERIC_PHY
+	help
+	  Say 'Y' here to add support for MediaTek MT7621 PCI PHY driver,
+

drivers/staging/mt7621-pci-phy/Makefile

@@ -0,0 +1 @@
+obj-$(CONFIG_SOC_MT7621)       += pci-mt7621-phy.o

drivers/staging/mt7621-pci-phy/TODO

@@ -0,0 +1,4 @@
+
+- general code review and cleanup
+
+Cc:  NeilBrown <neil@brown.name> and Sergio Paracuellos <sergio.paracuellos@gmail.com>

drivers/staging/mt7621-pci-phy/pci-mt7621-phy.c

@@ -0,0 +1,387 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Mediatek MT7621 PCI PHY Driver
+ * Author: Sergio Paracuellos <sergio.paracuellos@gmail.com>
+ */
+
+#include <dt-bindings/phy/phy.h>
+#include <linux/bitops.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <mt7621.h>
+#include <ralink_regs.h>
+
+#define RALINK_CLKCFG1			0x30
+#define CHIP_REV_MT7621_E2		0x0101
+
+#define PCIE_PORT_CLK_EN(x)		BIT(24 + (x))
+
+#define RG_PE1_PIPE_REG			0x02c
+#define RG_PE1_PIPE_RST			BIT(12)
+#define RG_PE1_PIPE_CMD_FRC		BIT(4)
+
+#define RG_P0_TO_P1_WIDTH		0x100
+#define RG_PE1_H_LCDDS_REG		0x49c
+#define RG_PE1_H_LCDDS_PCW		GENMASK(30, 0)
+#define RG_PE1_H_LCDDS_PCW_VAL(x)	((0x7fffffff & (x)) << 0)
+
+#define RG_PE1_FRC_H_XTAL_REG		0x400
+#define RG_PE1_FRC_H_XTAL_TYPE          BIT(8)
+#define RG_PE1_H_XTAL_TYPE              GENMASK(10, 9)
+#define RG_PE1_H_XTAL_TYPE_VAL(x)       ((0x3 & (x)) << 9)
+
+#define RG_PE1_FRC_PHY_REG		0x000
+#define RG_PE1_FRC_PHY_EN               BIT(4)
+#define RG_PE1_PHY_EN                   BIT(5)
+
+#define RG_PE1_H_PLL_REG		0x490
+#define RG_PE1_H_PLL_BC			GENMASK(23, 22)
+#define RG_PE1_H_PLL_BC_VAL(x)		((0x3 & (x)) << 22)
+#define RG_PE1_H_PLL_BP			GENMASK(21, 18)
+#define RG_PE1_H_PLL_BP_VAL(x)		((0xf & (x)) << 18)
+#define RG_PE1_H_PLL_IR			GENMASK(15, 12)
+#define RG_PE1_H_PLL_IR_VAL(x)		((0xf & (x)) << 12)
+#define RG_PE1_H_PLL_IC			GENMASK(11, 8)
+#define RG_PE1_H_PLL_IC_VAL(x)		((0xf & (x)) << 8)
+#define RG_PE1_H_PLL_PREDIV             GENMASK(7, 6)
+#define RG_PE1_H_PLL_PREDIV_VAL(x)      ((0x3 & (x)) << 6)
+#define RG_PE1_PLL_DIVEN		GENMASK(3, 1)
+#define RG_PE1_PLL_DIVEN_VAL(x)		((0x7 & (x)) << 1)
+
+#define RG_PE1_H_PLL_FBKSEL_REG		0x4bc
+#define RG_PE1_H_PLL_FBKSEL             GENMASK(5, 4)
+#define RG_PE1_H_PLL_FBKSEL_VAL(x)      ((0x3 & (x)) << 4)
+
+#define	RG_PE1_H_LCDDS_SSC_PRD_REG	0x4a4
+#define RG_PE1_H_LCDDS_SSC_PRD          GENMASK(15, 0)
+#define RG_PE1_H_LCDDS_SSC_PRD_VAL(x)   ((0xffff & (x)) << 0)
+
+#define RG_PE1_H_LCDDS_SSC_DELTA_REG	0x4a8
+#define RG_PE1_H_LCDDS_SSC_DELTA        GENMASK(11, 0)
+#define RG_PE1_H_LCDDS_SSC_DELTA_VAL(x) ((0xfff & (x)) << 0)
+#define RG_PE1_H_LCDDS_SSC_DELTA1       GENMASK(27, 16)
+#define RG_PE1_H_LCDDS_SSC_DELTA1_VAL(x) ((0xff & (x)) << 16)
+
+#define RG_PE1_LCDDS_CLK_PH_INV_REG	0x4a0
+#define RG_PE1_LCDDS_CLK_PH_INV		BIT(5)
+
+#define RG_PE1_H_PLL_BR_REG		0x4ac
+#define RG_PE1_H_PLL_BR			GENMASK(18, 16)
+#define RG_PE1_H_PLL_BR_VAL(x)		((0x7 & (x)) << 16)
+
+#define	RG_PE1_MSTCKDIV_REG		0x414
+#define RG_PE1_MSTCKDIV			GENMASK(7, 6)
+#define RG_PE1_MSTCKDIV_VAL(x)		((0x3 & (x)) << 6)
+
+#define RG_PE1_FRC_MSTCKDIV		BIT(5)
+
+/**
+ * struct mt7621_pci_phy_instance - Mt7621 Pcie PHY device
+ * @phy: pointer to the kernel PHY device
+ * @port_base: base register
+ * @index: internal ID to identify the Mt7621 PCIe PHY
+ */
+struct mt7621_pci_phy_instance {
+	struct phy *phy;
+	void __iomem *port_base;
+	u32 index;
+};
+
+/**
+ * struct mt7621_pci_phy - Mt7621 Pcie PHY core
+ * @dev: pointer to device
+ * @phys: pointer to Mt7621 PHY device
+ * @nphys: number of PHY devices for this core
+ */
+struct mt7621_pci_phy {
+	struct device *dev;
+	struct mt7621_pci_phy_instance **phys;
+	int nphys;
+};
+
+static inline u32 phy_read(struct mt7621_pci_phy_instance *instance, u32 reg)
+{
+	return readl(instance->port_base + reg);
+}
+
+static inline void phy_write(struct mt7621_pci_phy_instance *instance,
+			     u32 val, u32 reg)
+{
+	writel(val, instance->port_base + reg);
+}
+
+static void mt7621_bypass_pipe_rst(struct mt7621_pci_phy *phy,
+				   struct mt7621_pci_phy_instance *instance)
+{
+	u32 offset = (instance->index != 1) ?
+		RG_PE1_PIPE_REG : RG_PE1_PIPE_REG + RG_P0_TO_P1_WIDTH;
+	u32 reg;
+
+	reg = phy_read(instance, offset);
+	reg &= ~(RG_PE1_PIPE_RST | RG_PE1_PIPE_CMD_FRC);
+	reg |= (RG_PE1_PIPE_RST | RG_PE1_PIPE_CMD_FRC);
+	phy_write(instance, reg, offset);
+}
+
+static void mt7621_set_phy_for_ssc(struct mt7621_pci_phy *phy,
+				   struct mt7621_pci_phy_instance *instance)
+{
+	struct device *dev = phy->dev;
+	u32 reg = rt_sysc_r32(SYSC_REG_SYSTEM_CONFIG0);
+	u32 offset;
+	u32 val;
+
+	reg = (reg >> 6) & 0x7;
+	/* Set PCIe Port PHY to disable SSC */
+	/* Debug Xtal Type */
+	val = phy_read(instance, RG_PE1_FRC_H_XTAL_REG);
+	val &= ~(RG_PE1_FRC_H_XTAL_TYPE | RG_PE1_H_XTAL_TYPE);
+	val |= RG_PE1_FRC_H_XTAL_TYPE;
+	val |= RG_PE1_H_XTAL_TYPE_VAL(0x00);
+	phy_write(instance, val, RG_PE1_FRC_H_XTAL_REG);
+
+	/* disable port */
+	offset = (instance->index != 1) ?
+		RG_PE1_FRC_PHY_REG : RG_PE1_FRC_PHY_REG + RG_P0_TO_P1_WIDTH;
+	val = phy_read(instance, offset);
+	val &= ~(RG_PE1_FRC_PHY_EN | RG_PE1_PHY_EN);
+	val |= RG_PE1_FRC_PHY_EN;
+	phy_write(instance, val, offset);
+
+	/* Set Pre-divider ratio (for host mode) */
+	val = phy_read(instance, RG_PE1_H_PLL_REG);
+	val &= ~(RG_PE1_H_PLL_PREDIV);
+
+	if (reg <= 5 && reg >= 3) { /* 40MHz Xtal */
+		val |= RG_PE1_H_PLL_PREDIV_VAL(0x01);
+		phy_write(instance, val, RG_PE1_H_PLL_REG);
+		dev_info(dev, "Xtal is 40MHz\n");
+	} else { /* 25MHz | 20MHz Xtal */
+		val |= RG_PE1_H_PLL_PREDIV_VAL(0x00);
+		phy_write(instance, val, RG_PE1_H_PLL_REG);
+		if (reg >= 6) {
+			dev_info(dev, "Xtal is 25MHz\n");
+
+			/* Select feedback clock */
+			val = phy_read(instance, RG_PE1_H_PLL_FBKSEL_REG);
+			val &= ~(RG_PE1_H_PLL_FBKSEL);
+			val |= RG_PE1_H_PLL_FBKSEL_VAL(0x01);
+			phy_write(instance, val, RG_PE1_H_PLL_FBKSEL_REG);
+
+			/* DDS NCPO PCW (for host mode) */
+			val = phy_read(instance, RG_PE1_H_LCDDS_SSC_PRD_REG);
+			val &= ~(RG_PE1_H_LCDDS_SSC_PRD);
+			val |= RG_PE1_H_LCDDS_SSC_PRD_VAL(0x18000000);
+			phy_write(instance, val, RG_PE1_H_LCDDS_SSC_PRD_REG);
+
+			/* DDS SSC dither period control */
+			val = phy_read(instance, RG_PE1_H_LCDDS_SSC_PRD_REG);
+			val &= ~(RG_PE1_H_LCDDS_SSC_PRD);
+			val |= RG_PE1_H_LCDDS_SSC_PRD_VAL(0x18d);
+			phy_write(instance, val, RG_PE1_H_LCDDS_SSC_PRD_REG);
+
+			/* DDS SSC dither amplitude control */
+			val = phy_read(instance, RG_PE1_H_LCDDS_SSC_DELTA_REG);
+			val &= ~(RG_PE1_H_LCDDS_SSC_DELTA |
+				 RG_PE1_H_LCDDS_SSC_DELTA1);
+			val |= RG_PE1_H_LCDDS_SSC_DELTA_VAL(0x4a);
+			val |= RG_PE1_H_LCDDS_SSC_DELTA1_VAL(0x4a);
+			phy_write(instance, val, RG_PE1_H_LCDDS_SSC_DELTA_REG);
+		} else {
+			dev_info(dev, "Xtal is 20MHz\n");
+		}
+	}
+
+	/* DDS clock inversion */
+	val = phy_read(instance, RG_PE1_LCDDS_CLK_PH_INV_REG);
+	val &= ~(RG_PE1_LCDDS_CLK_PH_INV);
+	val |= RG_PE1_LCDDS_CLK_PH_INV;
+	phy_write(instance, val, RG_PE1_LCDDS_CLK_PH_INV_REG);
+
+	/* Set PLL bits */
+	val = phy_read(instance, RG_PE1_H_PLL_REG);
+	val &= ~(RG_PE1_H_PLL_BC | RG_PE1_H_PLL_BP | RG_PE1_H_PLL_IR |
+		 RG_PE1_H_PLL_IC | RG_PE1_PLL_DIVEN);
+	val |= RG_PE1_H_PLL_BC_VAL(0x02);
+	val |= RG_PE1_H_PLL_BP_VAL(0x06);
+	val |= RG_PE1_H_PLL_IR_VAL(0x02);
+	val |= RG_PE1_H_PLL_IC_VAL(0x01);
+	val |= RG_PE1_PLL_DIVEN_VAL(0x02);
+	phy_write(instance, val, RG_PE1_H_PLL_REG);
+
+	val = phy_read(instance, RG_PE1_H_PLL_BR_REG);
+	val &= ~(RG_PE1_H_PLL_BR);
+	val |= RG_PE1_H_PLL_BR_VAL(0x00);
+	phy_write(instance, val, RG_PE1_H_PLL_BR_REG);
+
+	if (reg <= 5 && reg >= 3) { /* 40MHz Xtal */
+		/* set force mode enable of da_pe1_mstckdiv */
+		val = phy_read(instance, RG_PE1_MSTCKDIV_REG);
+		val &= ~(RG_PE1_MSTCKDIV | RG_PE1_FRC_MSTCKDIV);
+		val |= (RG_PE1_MSTCKDIV_VAL(0x01) | RG_PE1_FRC_MSTCKDIV);
+		phy_write(instance, val, RG_PE1_MSTCKDIV_REG);
+	}
+}
+
+static int mt7621_pci_phy_init(struct phy *phy)
+{
+	struct mt7621_pci_phy_instance *instance = phy_get_drvdata(phy);
+	struct mt7621_pci_phy *mphy = dev_get_drvdata(phy->dev.parent);
+	u32 chip_rev_id = rt_sysc_r32(SYSC_REG_CHIP_REV);
+
+	if ((chip_rev_id & 0xFFFF) == CHIP_REV_MT7621_E2)
+		mt7621_bypass_pipe_rst(mphy, instance);
+
+	mt7621_set_phy_for_ssc(mphy, instance);
+
+	return 0;
+}
+
+static int mt7621_pci_phy_power_on(struct phy *phy)
+{
+	struct mt7621_pci_phy_instance *instance = phy_get_drvdata(phy);
+	u32 offset = (instance->index != 1) ?
+		RG_PE1_FRC_PHY_REG : RG_PE1_FRC_PHY_REG + RG_P0_TO_P1_WIDTH;
+	u32 val;
+
+	/* Enable PHY and disable force mode */
+	val = phy_read(instance, offset);
+	val &= ~(RG_PE1_FRC_PHY_EN | RG_PE1_PHY_EN);
+	val |= (RG_PE1_FRC_PHY_EN | RG_PE1_PHY_EN);
+	phy_write(instance, val, offset);
+
+	return 0;
+}
+
+static int mt7621_pci_phy_power_off(struct phy *phy)
+{
+	struct mt7621_pci_phy_instance *instance = phy_get_drvdata(phy);
+	u32 offset = (instance->index != 1) ?
+		RG_PE1_FRC_PHY_REG : RG_PE1_FRC_PHY_REG + RG_P0_TO_P1_WIDTH;
+	u32 val;
+
+	/* Disable PHY */
+	val = phy_read(instance, offset);
+	val &= ~(RG_PE1_FRC_PHY_EN | RG_PE1_PHY_EN);
+	val |= RG_PE1_FRC_PHY_EN;
+	phy_write(instance, val, offset);
+
+	return 0;
+}
+
+static int mt7621_pci_phy_exit(struct phy *phy)
+{
+	struct mt7621_pci_phy_instance *instance = phy_get_drvdata(phy);
+
+	rt_sysc_m32(PCIE_PORT_CLK_EN(instance->index), 0, RALINK_CLKCFG1);
+
+	return 0;
+}
+
+static const struct phy_ops mt7621_pci_phy_ops = {
+	.init		= mt7621_pci_phy_init,
+	.exit		= mt7621_pci_phy_exit,
+	.power_on	= mt7621_pci_phy_power_on,
+	.power_off	= mt7621_pci_phy_power_off,
+	.owner		= THIS_MODULE,
+};
+
+static int mt7621_pci_phy_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct device_node *child_np;
+	struct phy_provider *provider;
+	struct mt7621_pci_phy *phy;
+	struct resource res;
+	int port, ret;
+	void __iomem *port_base;
+
+	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
+	if (!phy)
+		return -ENOMEM;
+
+	phy->nphys = of_get_child_count(np);
+	phy->phys = devm_kcalloc(dev, phy->nphys,
+				 sizeof(*phy->phys), GFP_KERNEL);
+	if (!phy->phys)
+		return -ENOMEM;
+
+	phy->dev = dev;
+	platform_set_drvdata(pdev, phy);
+
+	ret = of_address_to_resource(np, 0, &res);
+	if (ret) {
+		dev_err(dev, "failed to get address resource(id-%d)\n", port);
+		return ret;
+	}
+
+	port_base = devm_ioremap_resource(dev, &res);
+	if (IS_ERR(port_base)) {
+		dev_err(dev, "failed to remap phy regs\n");
+		return PTR_ERR(port_base);
+	}
+
+	port = 0;
+	for_each_child_of_node(np, child_np) {
+		struct mt7621_pci_phy_instance *instance;
+		struct phy *pphy;
+
+		instance = devm_kzalloc(dev, sizeof(*instance), GFP_KERNEL);
+		if (!instance) {
+			ret = -ENOMEM;
+			goto put_child;
+		}
+
+		phy->phys[port] = instance;
+
+		pphy = devm_phy_create(dev, child_np, &mt7621_pci_phy_ops);
+		if (IS_ERR(phy)) {
+			dev_err(dev, "failed to create phy\n");
+			ret = PTR_ERR(phy);
+			goto put_child;
+		}
+
+		instance->port_base = port_base;
+		instance->phy = pphy;
+		instance->index = port;
+		phy_set_drvdata(pphy, instance);
+		port++;
+	}
+
+	provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+
+	return PTR_ERR_OR_ZERO(provider);
+
+put_child:
+	of_node_put(child_np);
+	return ret;
+}
+
+static const struct of_device_id mt7621_pci_phy_ids[] = {
+	{ .compatible = "mediatek,mt7621-pci-phy" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mt7621_pci_ids);
+
+static struct platform_driver mt7621_pci_phy_driver = {
+	.probe = mt7621_pci_phy_probe,
+	.driver = {
+		.name = "mt7621-pci-phy",
+		.of_match_table = of_match_ptr(mt7621_pci_phy_ids),
+	},
+};
+
+static int __init mt7621_pci_phy_drv_init(void)
+{
+	return platform_driver_register(&mt7621_pci_phy_driver);
+}
+
+arch_initcall(mt7621_pci_phy_drv_init);
+
+MODULE_AUTHOR("Sergio Paracuellos <sergio.paracuellos@gmail.com>");
+MODULE_DESCRIPTION("MediaTek MT7621 PCIe PHY driver");
+MODULE_LICENSE("GPL v2");