1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Renesas USB driver R-Car Gen. 3 initialization and power control
4  *
5  * Copyright (C) 2016 Renesas Electronics Corporation
6  */
7 
8 #include <linux/delay.h>
9 #include <linux/io.h>
10 #include "common.h"
11 #include "rcar3.h"
12 
13 #define LPSTS		0x102
14 #define UGCTRL		0x180	/* 32-bit register */
15 #define UGCTRL2		0x184	/* 32-bit register */
16 #define UGSTS		0x188	/* 32-bit register */
17 
18 /* Low Power Status register (LPSTS) */
19 #define LPSTS_SUSPM	0x4000
20 
21 /* R-Car D3 only: USB General control register (UGCTRL) */
22 #define UGCTRL_PLLRESET		0x00000001
23 #define UGCTRL_CONNECT		0x00000004
24 
25 /*
26  * USB General control register 2 (UGCTRL2)
27  * Remarks: bit[31:11] and bit[9:6] should be 0
28  */
29 #define UGCTRL2_RESERVED_3	0x00000001	/* bit[3:0] should be B'0001 */
30 #define UGCTRL2_USB0SEL_EHCI	0x00000010
31 #define UGCTRL2_USB0SEL_HSUSB	0x00000020
32 #define UGCTRL2_USB0SEL_OTG	0x00000030
33 #define UGCTRL2_VBUSSEL		0x00000400
34 
35 /* R-Car D3 only: USB General status register (UGSTS) */
36 #define UGSTS_LOCK		0x00000100
37 
38 static void usbhs_write32(struct usbhs_priv *priv, u32 reg, u32 data)
39 {
40 	iowrite32(data, priv->base + reg);
41 }
42 
43 static u32 usbhs_read32(struct usbhs_priv *priv, u32 reg)
44 {
45 	return ioread32(priv->base + reg);
46 }
47 
48 static void usbhs_rcar3_set_ugctrl2(struct usbhs_priv *priv, u32 val)
49 {
50 	usbhs_write32(priv, UGCTRL2, val | UGCTRL2_RESERVED_3);
51 }
52 
53 static void usbhs_rcar3_set_usbsel(struct usbhs_priv *priv, bool ehci)
54 {
55 	if (ehci)
56 		usbhs_rcar3_set_ugctrl2(priv, UGCTRL2_USB0SEL_EHCI);
57 	else
58 		usbhs_rcar3_set_ugctrl2(priv, UGCTRL2_USB0SEL_HSUSB);
59 }
60 
61 static int usbhs_rcar3_power_ctrl(struct platform_device *pdev,
62 				void __iomem *base, int enable)
63 {
64 	struct usbhs_priv *priv = usbhs_pdev_to_priv(pdev);
65 
66 	usbhs_rcar3_set_ugctrl2(priv, UGCTRL2_USB0SEL_OTG | UGCTRL2_VBUSSEL);
67 
68 	if (enable) {
69 		usbhs_bset(priv, LPSTS, LPSTS_SUSPM, LPSTS_SUSPM);
70 		/* The controller on R-Car Gen3 needs to wait up to 45 usec */
71 		udelay(45);
72 	} else {
73 		usbhs_bset(priv, LPSTS, LPSTS_SUSPM, 0);
74 	}
75 
76 	return 0;
77 }
78 
79 /* R-Car D3 needs to release UGCTRL.PLLRESET */
80 static int usbhs_rcar3_power_and_pll_ctrl(struct platform_device *pdev,
81 					  void __iomem *base, int enable)
82 {
83 	struct usbhs_priv *priv = usbhs_pdev_to_priv(pdev);
84 	u32 val;
85 	int timeout = 1000;
86 	bool is_host = false;
87 
88 	if (enable) {
89 		usbhs_write32(priv, UGCTRL, 0);	/* release PLLRESET */
90 		if (priv->edev)
91 			is_host = extcon_get_state(priv->edev, EXTCON_USB_HOST);
92 
93 		usbhs_rcar3_set_usbsel(priv, is_host);
94 
95 		usbhs_bset(priv, LPSTS, LPSTS_SUSPM, LPSTS_SUSPM);
96 		do {
97 			val = usbhs_read32(priv, UGSTS);
98 			udelay(1);
99 		} while (!(val & UGSTS_LOCK) && timeout--);
100 		usbhs_write32(priv, UGCTRL, UGCTRL_CONNECT);
101 	} else {
102 		usbhs_write32(priv, UGCTRL, 0);
103 		usbhs_bset(priv, LPSTS, LPSTS_SUSPM, 0);
104 		usbhs_write32(priv, UGCTRL, UGCTRL_PLLRESET);
105 	}
106 
107 	return 0;
108 }
109 
110 static int usbhs_rcar3_get_id(struct platform_device *pdev)
111 {
112 	return USBHS_GADGET;
113 }
114 
115 static int usbhs_rcar3_notifier(struct notifier_block *nb, unsigned long event,
116 				void *data)
117 {
118 	struct usbhs_priv *priv = container_of(nb, struct usbhs_priv, nb);
119 
120 	usbhs_rcar3_set_usbsel(priv, !!event);
121 
122 	return NOTIFY_DONE;
123 }
124 
125 const struct renesas_usbhs_platform_callback usbhs_rcar3_ops = {
126 	.power_ctrl = usbhs_rcar3_power_ctrl,
127 	.get_id = usbhs_rcar3_get_id,
128 };
129 
130 const struct renesas_usbhs_platform_callback usbhs_rcar3_with_pll_ops = {
131 	.power_ctrl = usbhs_rcar3_power_and_pll_ctrl,
132 	.get_id = usbhs_rcar3_get_id,
133 	.notifier = usbhs_rcar3_notifier,
134 };
135