1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2018 Marvell
4  *
5  * Authors:
6  *   Igal Liberman <igall@marvell.com>
7  *   Miquèl Raynal <miquel.raynal@bootlin.com>
8  *
9  * Marvell A3700 UTMI PHY driver
10  */
11 
12 #include <linux/io.h>
13 #include <linux/iopoll.h>
14 #include <linux/mfd/syscon.h>
15 #include <linux/module.h>
16 #include <linux/of.h>
17 #include <linux/phy/phy.h>
18 #include <linux/platform_device.h>
19 #include <linux/regmap.h>
20 
21 /* Armada 3700 UTMI PHY registers */
22 #define USB2_PHY_PLL_CTRL_REG0			0x0
23 #define   PLL_REF_DIV_OFF			0
24 #define   PLL_REF_DIV_MASK			GENMASK(6, 0)
25 #define   PLL_REF_DIV_5				5
26 #define   PLL_FB_DIV_OFF			16
27 #define   PLL_FB_DIV_MASK			GENMASK(24, 16)
28 #define   PLL_FB_DIV_96				96
29 #define   PLL_SEL_LPFR_OFF			28
30 #define   PLL_SEL_LPFR_MASK			GENMASK(29, 28)
31 #define   PLL_READY				BIT(31)
32 #define USB2_PHY_CAL_CTRL			0x8
33 #define   PHY_PLLCAL_DONE			BIT(31)
34 #define   PHY_IMPCAL_DONE			BIT(23)
35 #define USB2_RX_CHAN_CTRL1			0x18
36 #define   USB2PHY_SQCAL_DONE			BIT(31)
37 #define USB2_PHY_OTG_CTRL			0x34
38 #define   PHY_PU_OTG				BIT(4)
39 #define USB2_PHY_CHRGR_DETECT			0x38
40 #define   PHY_CDP_EN				BIT(2)
41 #define   PHY_DCP_EN				BIT(3)
42 #define   PHY_PD_EN				BIT(4)
43 #define   PHY_PU_CHRG_DTC			BIT(5)
44 #define   PHY_CDP_DM_AUTO			BIT(7)
45 #define   PHY_ENSWITCH_DP			BIT(12)
46 #define   PHY_ENSWITCH_DM			BIT(13)
47 
48 /* Armada 3700 USB miscellaneous registers */
49 #define USB2_PHY_CTRL(usb32)			(usb32 ? 0x20 : 0x4)
50 #define   RB_USB2PHY_PU				BIT(0)
51 #define   USB2_DP_PULLDN_DEV_MODE		BIT(5)
52 #define   USB2_DM_PULLDN_DEV_MODE		BIT(6)
53 #define   RB_USB2PHY_SUSPM(usb32)		(usb32 ? BIT(14) : BIT(7))
54 
55 #define PLL_LOCK_DELAY_US			10000
56 #define PLL_LOCK_TIMEOUT_US			1000000
57 
58 /**
59  * struct mvebu_a3700_utmi_caps - PHY capabilities
60  *
61  * @usb32: Flag indicating which PHY is in use (impacts the register map):
62  *           - The UTMI PHY wired to the USB3/USB2 controller (otg)
63  *           - The UTMI PHY wired to the USB2 controller (host only)
64  * @ops: PHY operations
65  */
66 struct mvebu_a3700_utmi_caps {
67 	int usb32;
68 	const struct phy_ops *ops;
69 };
70 
71 /**
72  * struct mvebu_a3700_utmi - PHY driver data
73  *
74  * @regs: PHY registers
75  * @usb_misc: Regmap with USB miscellaneous registers including PHY ones
76  * @caps: PHY capabilities
77  * @phy: PHY handle
78  */
79 struct mvebu_a3700_utmi {
80 	void __iomem *regs;
81 	struct regmap *usb_misc;
82 	const struct mvebu_a3700_utmi_caps *caps;
83 	struct phy *phy;
84 };
85 
mvebu_a3700_utmi_phy_power_on(struct phy * phy)86 static int mvebu_a3700_utmi_phy_power_on(struct phy *phy)
87 {
88 	struct mvebu_a3700_utmi *utmi = phy_get_drvdata(phy);
89 	struct device *dev = &phy->dev;
90 	int usb32 = utmi->caps->usb32;
91 	int ret = 0;
92 	u32 reg;
93 
94 	/*
95 	 * Setup PLL. 40MHz clock used to be the default, being 25MHz now.
96 	 * See "PLL Settings for Typical REFCLK" table.
97 	 */
98 	reg = readl(utmi->regs + USB2_PHY_PLL_CTRL_REG0);
99 	reg &= ~(PLL_REF_DIV_MASK | PLL_FB_DIV_MASK | PLL_SEL_LPFR_MASK);
100 	reg |= (PLL_REF_DIV_5 << PLL_REF_DIV_OFF) |
101 	       (PLL_FB_DIV_96 << PLL_FB_DIV_OFF);
102 	writel(reg, utmi->regs + USB2_PHY_PLL_CTRL_REG0);
103 
104 	/* Enable PHY pull up and disable USB2 suspend */
105 	regmap_update_bits(utmi->usb_misc, USB2_PHY_CTRL(usb32),
106 			   RB_USB2PHY_SUSPM(usb32) | RB_USB2PHY_PU,
107 			   RB_USB2PHY_SUSPM(usb32) | RB_USB2PHY_PU);
108 
109 	if (usb32) {
110 		/* Power up OTG module */
111 		reg = readl(utmi->regs + USB2_PHY_OTG_CTRL);
112 		reg |= PHY_PU_OTG;
113 		writel(reg, utmi->regs + USB2_PHY_OTG_CTRL);
114 
115 		/* Disable PHY charger detection */
116 		reg = readl(utmi->regs + USB2_PHY_CHRGR_DETECT);
117 		reg &= ~(PHY_CDP_EN | PHY_DCP_EN | PHY_PD_EN | PHY_PU_CHRG_DTC |
118 			 PHY_CDP_DM_AUTO | PHY_ENSWITCH_DP | PHY_ENSWITCH_DM);
119 		writel(reg, utmi->regs + USB2_PHY_CHRGR_DETECT);
120 
121 		/* Disable PHY DP/DM pull-down (used for device mode) */
122 		regmap_update_bits(utmi->usb_misc, USB2_PHY_CTRL(usb32),
123 				   USB2_DP_PULLDN_DEV_MODE |
124 				   USB2_DM_PULLDN_DEV_MODE, 0);
125 	}
126 
127 	/* Wait for PLL calibration */
128 	ret = readl_poll_timeout(utmi->regs + USB2_PHY_CAL_CTRL, reg,
129 				 reg & PHY_PLLCAL_DONE,
130 				 PLL_LOCK_DELAY_US, PLL_LOCK_TIMEOUT_US);
131 	if (ret) {
132 		dev_err(dev, "Failed to end USB2 PLL calibration\n");
133 		return ret;
134 	}
135 
136 	/* Wait for impedance calibration */
137 	ret = readl_poll_timeout(utmi->regs + USB2_PHY_CAL_CTRL, reg,
138 				 reg & PHY_IMPCAL_DONE,
139 				 PLL_LOCK_DELAY_US, PLL_LOCK_TIMEOUT_US);
140 	if (ret) {
141 		dev_err(dev, "Failed to end USB2 impedance calibration\n");
142 		return ret;
143 	}
144 
145 	/* Wait for squelch calibration */
146 	ret = readl_poll_timeout(utmi->regs + USB2_RX_CHAN_CTRL1, reg,
147 				 reg & USB2PHY_SQCAL_DONE,
148 				 PLL_LOCK_DELAY_US, PLL_LOCK_TIMEOUT_US);
149 	if (ret) {
150 		dev_err(dev, "Failed to end USB2 unknown calibration\n");
151 		return ret;
152 	}
153 
154 	/* Wait for PLL to be locked */
155 	ret = readl_poll_timeout(utmi->regs + USB2_PHY_PLL_CTRL_REG0, reg,
156 				 reg & PLL_READY,
157 				 PLL_LOCK_DELAY_US, PLL_LOCK_TIMEOUT_US);
158 	if (ret)
159 		dev_err(dev, "Failed to lock USB2 PLL\n");
160 
161 	return ret;
162 }
163 
mvebu_a3700_utmi_phy_power_off(struct phy * phy)164 static int mvebu_a3700_utmi_phy_power_off(struct phy *phy)
165 {
166 	struct mvebu_a3700_utmi *utmi = phy_get_drvdata(phy);
167 	int usb32 = utmi->caps->usb32;
168 	u32 reg;
169 
170 	/* Disable PHY pull-up and enable USB2 suspend */
171 	reg = readl(utmi->regs + USB2_PHY_CTRL(usb32));
172 	reg &= ~(RB_USB2PHY_PU | RB_USB2PHY_SUSPM(usb32));
173 	writel(reg, utmi->regs + USB2_PHY_CTRL(usb32));
174 
175 	/* Power down OTG module */
176 	if (usb32) {
177 		reg = readl(utmi->regs + USB2_PHY_OTG_CTRL);
178 		reg &= ~PHY_PU_OTG;
179 		writel(reg, utmi->regs + USB2_PHY_OTG_CTRL);
180 	}
181 
182 	return 0;
183 }
184 
185 static const struct phy_ops mvebu_a3700_utmi_phy_ops = {
186 	.power_on = mvebu_a3700_utmi_phy_power_on,
187 	.power_off = mvebu_a3700_utmi_phy_power_off,
188 	.owner = THIS_MODULE,
189 };
190 
191 static const struct mvebu_a3700_utmi_caps mvebu_a3700_utmi_otg_phy_caps = {
192 	.usb32 = true,
193 	.ops = &mvebu_a3700_utmi_phy_ops,
194 };
195 
196 static const struct mvebu_a3700_utmi_caps mvebu_a3700_utmi_host_phy_caps = {
197 	.usb32 = false,
198 	.ops = &mvebu_a3700_utmi_phy_ops,
199 };
200 
201 static const struct of_device_id mvebu_a3700_utmi_of_match[] = {
202 	{
203 		.compatible = "marvell,a3700-utmi-otg-phy",
204 		.data = &mvebu_a3700_utmi_otg_phy_caps,
205 	},
206 	{
207 		.compatible = "marvell,a3700-utmi-host-phy",
208 		.data = &mvebu_a3700_utmi_host_phy_caps,
209 	},
210 	{},
211 };
212 MODULE_DEVICE_TABLE(of, mvebu_a3700_utmi_of_match);
213 
mvebu_a3700_utmi_phy_probe(struct platform_device * pdev)214 static int mvebu_a3700_utmi_phy_probe(struct platform_device *pdev)
215 {
216 	struct device *dev = &pdev->dev;
217 	struct mvebu_a3700_utmi *utmi;
218 	struct phy_provider *provider;
219 
220 	utmi = devm_kzalloc(dev, sizeof(*utmi), GFP_KERNEL);
221 	if (!utmi)
222 		return -ENOMEM;
223 
224 	/* Get UTMI memory region */
225 	utmi->regs = devm_platform_ioremap_resource(pdev, 0);
226 	if (IS_ERR(utmi->regs))
227 		return PTR_ERR(utmi->regs);
228 
229 	/* Get miscellaneous Host/PHY region */
230 	utmi->usb_misc = syscon_regmap_lookup_by_phandle(dev->of_node,
231 							 "marvell,usb-misc-reg");
232 	if (IS_ERR(utmi->usb_misc)) {
233 		dev_err(dev,
234 			"Missing USB misc purpose system controller\n");
235 		return PTR_ERR(utmi->usb_misc);
236 	}
237 
238 	/* Retrieve PHY capabilities */
239 	utmi->caps = of_device_get_match_data(dev);
240 
241 	/* Instantiate the PHY */
242 	utmi->phy = devm_phy_create(dev, NULL, utmi->caps->ops);
243 	if (IS_ERR(utmi->phy)) {
244 		dev_err(dev, "Failed to create the UTMI PHY\n");
245 		return PTR_ERR(utmi->phy);
246 	}
247 
248 	phy_set_drvdata(utmi->phy, utmi);
249 
250 	/* Ensure the PHY is powered off */
251 	utmi->caps->ops->power_off(utmi->phy);
252 
253 	provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
254 
255 	return PTR_ERR_OR_ZERO(provider);
256 }
257 
258 static struct platform_driver mvebu_a3700_utmi_driver = {
259 	.probe	= mvebu_a3700_utmi_phy_probe,
260 	.driver	= {
261 		.name		= "mvebu-a3700-utmi-phy",
262 		.of_match_table	= mvebu_a3700_utmi_of_match,
263 	 },
264 };
265 module_platform_driver(mvebu_a3700_utmi_driver);
266 
267 MODULE_AUTHOR("Igal Liberman <igall@marvell.com>");
268 MODULE_AUTHOR("Miquel Raynal <miquel.raynal@bootlin.com>");
269 MODULE_DESCRIPTION("Marvell EBU A3700 UTMI PHY driver");
270 MODULE_LICENSE("GPL v2");
271