1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Broadcom Northstar USB 3.0 PHY Driver
4  *
5  * Copyright (C) 2016 Rafał Miłecki <rafal@milecki.pl>
6  * Copyright (C) 2016 Broadcom
7  *
8  * All magic values used for initialization (and related comments) were obtained
9  * from Broadcom's SDK:
10  * Copyright (c) Broadcom Corp, 2012
11  */
12 
13 #include <linux/bcma/bcma.h>
14 #include <linux/delay.h>
15 #include <linux/err.h>
16 #include <linux/iopoll.h>
17 #include <linux/mdio.h>
18 #include <linux/module.h>
19 #include <linux/of_address.h>
20 #include <linux/of_platform.h>
21 #include <linux/platform_device.h>
22 #include <linux/phy/phy.h>
23 #include <linux/slab.h>
24 
25 #define BCM_NS_USB3_PHY_BASE_ADDR_REG	0x1f
26 #define BCM_NS_USB3_PHY_PLL30_BLOCK	0x8000
27 #define BCM_NS_USB3_PHY_TX_PMD_BLOCK	0x8040
28 #define BCM_NS_USB3_PHY_PIPE_BLOCK	0x8060
29 
30 /* Registers of PLL30 block */
31 #define BCM_NS_USB3_PLL_CONTROL		0x01
32 #define BCM_NS_USB3_PLLA_CONTROL0	0x0a
33 #define BCM_NS_USB3_PLLA_CONTROL1	0x0b
34 
35 /* Registers of TX PMD block */
36 #define BCM_NS_USB3_TX_PMD_CONTROL1	0x01
37 
38 /* Registers of PIPE block */
39 #define BCM_NS_USB3_LFPS_CMP		0x02
40 #define BCM_NS_USB3_LFPS_DEGLITCH	0x03
41 
42 enum bcm_ns_family {
43 	BCM_NS_UNKNOWN,
44 	BCM_NS_AX,
45 	BCM_NS_BX,
46 };
47 
48 struct bcm_ns_usb3 {
49 	struct device *dev;
50 	enum bcm_ns_family family;
51 	void __iomem *dmp;
52 	struct mdio_device *mdiodev;
53 	struct phy *phy;
54 };
55 
56 static const struct of_device_id bcm_ns_usb3_id_table[] = {
57 	{
58 		.compatible = "brcm,ns-ax-usb3-phy",
59 		.data = (int *)BCM_NS_AX,
60 	},
61 	{
62 		.compatible = "brcm,ns-bx-usb3-phy",
63 		.data = (int *)BCM_NS_BX,
64 	},
65 	{},
66 };
67 
68 static int bcm_ns_usb3_mdio_phy_write(struct bcm_ns_usb3 *usb3, u16 reg,
69 				      u16 value);
70 
bcm_ns_usb3_phy_init_ns_bx(struct bcm_ns_usb3 * usb3)71 static int bcm_ns_usb3_phy_init_ns_bx(struct bcm_ns_usb3 *usb3)
72 {
73 	int err;
74 
75 	/* USB3 PLL Block */
76 	err = bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PHY_BASE_ADDR_REG,
77 					 BCM_NS_USB3_PHY_PLL30_BLOCK);
78 	if (err < 0)
79 		return err;
80 
81 	/* Assert Ana_Pllseq start */
82 	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PLL_CONTROL, 0x1000);
83 
84 	/* Assert CML Divider ratio to 26 */
85 	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PLLA_CONTROL0, 0x6400);
86 
87 	/* Asserting PLL Reset */
88 	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PLLA_CONTROL1, 0xc000);
89 
90 	/* Deaaserting PLL Reset */
91 	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PLLA_CONTROL1, 0x8000);
92 
93 	/* Deasserting USB3 system reset */
94 	writel(0, usb3->dmp + BCMA_RESET_CTL);
95 
96 	/* PLL frequency monitor enable */
97 	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PLL_CONTROL, 0x9000);
98 
99 	/* PIPE Block */
100 	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PHY_BASE_ADDR_REG,
101 				   BCM_NS_USB3_PHY_PIPE_BLOCK);
102 
103 	/* CMPMAX & CMPMINTH setting */
104 	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_LFPS_CMP, 0xf30d);
105 
106 	/* DEGLITCH MIN & MAX setting */
107 	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_LFPS_DEGLITCH, 0x6302);
108 
109 	/* TXPMD block */
110 	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PHY_BASE_ADDR_REG,
111 				   BCM_NS_USB3_PHY_TX_PMD_BLOCK);
112 
113 	/* Enabling SSC */
114 	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_TX_PMD_CONTROL1, 0x1003);
115 
116 	return 0;
117 }
118 
bcm_ns_usb3_phy_init_ns_ax(struct bcm_ns_usb3 * usb3)119 static int bcm_ns_usb3_phy_init_ns_ax(struct bcm_ns_usb3 *usb3)
120 {
121 	int err;
122 
123 	/* PLL30 block */
124 	err = bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PHY_BASE_ADDR_REG,
125 					 BCM_NS_USB3_PHY_PLL30_BLOCK);
126 	if (err < 0)
127 		return err;
128 
129 	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PLLA_CONTROL0, 0x6400);
130 
131 	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PHY_BASE_ADDR_REG, 0x80e0);
132 
133 	bcm_ns_usb3_mdio_phy_write(usb3, 0x02, 0x009c);
134 
135 	/* Enable SSC */
136 	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_PHY_BASE_ADDR_REG,
137 				   BCM_NS_USB3_PHY_TX_PMD_BLOCK);
138 
139 	bcm_ns_usb3_mdio_phy_write(usb3, 0x02, 0x21d3);
140 
141 	bcm_ns_usb3_mdio_phy_write(usb3, BCM_NS_USB3_TX_PMD_CONTROL1, 0x1003);
142 
143 	/* Deasserting USB3 system reset */
144 	writel(0, usb3->dmp + BCMA_RESET_CTL);
145 
146 	return 0;
147 }
148 
bcm_ns_usb3_phy_init(struct phy * phy)149 static int bcm_ns_usb3_phy_init(struct phy *phy)
150 {
151 	struct bcm_ns_usb3 *usb3 = phy_get_drvdata(phy);
152 	int err;
153 
154 	/* Perform USB3 system soft reset */
155 	writel(BCMA_RESET_CTL_RESET, usb3->dmp + BCMA_RESET_CTL);
156 
157 	switch (usb3->family) {
158 	case BCM_NS_AX:
159 		err = bcm_ns_usb3_phy_init_ns_ax(usb3);
160 		break;
161 	case BCM_NS_BX:
162 		err = bcm_ns_usb3_phy_init_ns_bx(usb3);
163 		break;
164 	default:
165 		WARN_ON(1);
166 		err = -ENOTSUPP;
167 	}
168 
169 	return err;
170 }
171 
172 static const struct phy_ops ops = {
173 	.init		= bcm_ns_usb3_phy_init,
174 	.owner		= THIS_MODULE,
175 };
176 
177 /**************************************************
178  * MDIO driver code
179  **************************************************/
180 
bcm_ns_usb3_mdio_phy_write(struct bcm_ns_usb3 * usb3,u16 reg,u16 value)181 static int bcm_ns_usb3_mdio_phy_write(struct bcm_ns_usb3 *usb3, u16 reg,
182 				      u16 value)
183 {
184 	struct mdio_device *mdiodev = usb3->mdiodev;
185 
186 	return mdiodev_write(mdiodev, reg, value);
187 }
188 
bcm_ns_usb3_mdio_probe(struct mdio_device * mdiodev)189 static int bcm_ns_usb3_mdio_probe(struct mdio_device *mdiodev)
190 {
191 	struct device *dev = &mdiodev->dev;
192 	const struct of_device_id *of_id;
193 	struct phy_provider *phy_provider;
194 	struct device_node *syscon_np;
195 	struct bcm_ns_usb3 *usb3;
196 	struct resource res;
197 	int err;
198 
199 	usb3 = devm_kzalloc(dev, sizeof(*usb3), GFP_KERNEL);
200 	if (!usb3)
201 		return -ENOMEM;
202 
203 	usb3->dev = dev;
204 	usb3->mdiodev = mdiodev;
205 
206 	of_id = of_match_device(bcm_ns_usb3_id_table, dev);
207 	if (!of_id)
208 		return -EINVAL;
209 	usb3->family = (uintptr_t)of_id->data;
210 
211 	syscon_np = of_parse_phandle(dev->of_node, "usb3-dmp-syscon", 0);
212 	err = of_address_to_resource(syscon_np, 0, &res);
213 	of_node_put(syscon_np);
214 	if (err)
215 		return err;
216 
217 	usb3->dmp = devm_ioremap_resource(dev, &res);
218 	if (IS_ERR(usb3->dmp))
219 		return PTR_ERR(usb3->dmp);
220 
221 	usb3->phy = devm_phy_create(dev, NULL, &ops);
222 	if (IS_ERR(usb3->phy)) {
223 		dev_err(dev, "Failed to create PHY\n");
224 		return PTR_ERR(usb3->phy);
225 	}
226 
227 	phy_set_drvdata(usb3->phy, usb3);
228 
229 	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
230 
231 	return PTR_ERR_OR_ZERO(phy_provider);
232 }
233 
234 static struct mdio_driver bcm_ns_usb3_mdio_driver = {
235 	.mdiodrv = {
236 		.driver = {
237 			.name = "bcm_ns_mdio_usb3",
238 			.of_match_table = bcm_ns_usb3_id_table,
239 		},
240 	},
241 	.probe = bcm_ns_usb3_mdio_probe,
242 };
243 
244 mdio_module_driver(bcm_ns_usb3_mdio_driver);
245 
246 MODULE_LICENSE("GPL v2");
247 MODULE_DEVICE_TABLE(of, bcm_ns_usb3_id_table);
248