1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2016 Linaro Ltd
4  */
5 #include <linux/module.h>
6 #include <linux/ulpi/driver.h>
7 #include <linux/ulpi/regs.h>
8 #include <linux/phy/phy.h>
9 #include <linux/pinctrl/consumer.h>
10 #include <linux/pinctrl/pinctrl-state.h>
11 #include <linux/delay.h>
12 #include <linux/clk.h>
13 
14 #define ULPI_HSIC_CFG		0x30
15 #define ULPI_HSIC_IO_CAL	0x33
16 
17 struct qcom_usb_hsic_phy {
18 	struct ulpi *ulpi;
19 	struct phy *phy;
20 	struct pinctrl *pctl;
21 	struct clk *phy_clk;
22 	struct clk *cal_clk;
23 	struct clk *cal_sleep_clk;
24 };
25 
qcom_usb_hsic_phy_power_on(struct phy * phy)26 static int qcom_usb_hsic_phy_power_on(struct phy *phy)
27 {
28 	struct qcom_usb_hsic_phy *uphy = phy_get_drvdata(phy);
29 	struct ulpi *ulpi = uphy->ulpi;
30 	struct pinctrl_state *pins_default;
31 	int ret;
32 
33 	ret = clk_prepare_enable(uphy->phy_clk);
34 	if (ret)
35 		return ret;
36 
37 	ret = clk_prepare_enable(uphy->cal_clk);
38 	if (ret)
39 		goto err_cal;
40 
41 	ret = clk_prepare_enable(uphy->cal_sleep_clk);
42 	if (ret)
43 		goto err_sleep;
44 
45 	/* Set periodic calibration interval to ~2.048sec in HSIC_IO_CAL_REG */
46 	ret = ulpi_write(ulpi, ULPI_HSIC_IO_CAL, 0xff);
47 	if (ret)
48 		goto err_ulpi;
49 
50 	/* Enable periodic IO calibration in HSIC_CFG register */
51 	ret = ulpi_write(ulpi, ULPI_HSIC_CFG, 0xa8);
52 	if (ret)
53 		goto err_ulpi;
54 
55 	/* Configure pins for HSIC functionality */
56 	pins_default = pinctrl_lookup_state(uphy->pctl, PINCTRL_STATE_DEFAULT);
57 	if (IS_ERR(pins_default)) {
58 		ret = PTR_ERR(pins_default);
59 		goto err_ulpi;
60 	}
61 
62 	ret = pinctrl_select_state(uphy->pctl, pins_default);
63 	if (ret)
64 		goto err_ulpi;
65 
66 	 /* Enable HSIC mode in HSIC_CFG register */
67 	ret = ulpi_write(ulpi, ULPI_SET(ULPI_HSIC_CFG), 0x01);
68 	if (ret)
69 		goto err_ulpi;
70 
71 	/* Disable auto-resume */
72 	ret = ulpi_write(ulpi, ULPI_CLR(ULPI_IFC_CTRL),
73 			 ULPI_IFC_CTRL_AUTORESUME);
74 	if (ret)
75 		goto err_ulpi;
76 
77 	return ret;
78 err_ulpi:
79 	clk_disable_unprepare(uphy->cal_sleep_clk);
80 err_sleep:
81 	clk_disable_unprepare(uphy->cal_clk);
82 err_cal:
83 	clk_disable_unprepare(uphy->phy_clk);
84 	return ret;
85 }
86 
qcom_usb_hsic_phy_power_off(struct phy * phy)87 static int qcom_usb_hsic_phy_power_off(struct phy *phy)
88 {
89 	struct qcom_usb_hsic_phy *uphy = phy_get_drvdata(phy);
90 
91 	clk_disable_unprepare(uphy->cal_sleep_clk);
92 	clk_disable_unprepare(uphy->cal_clk);
93 	clk_disable_unprepare(uphy->phy_clk);
94 
95 	return 0;
96 }
97 
98 static const struct phy_ops qcom_usb_hsic_phy_ops = {
99 	.power_on = qcom_usb_hsic_phy_power_on,
100 	.power_off = qcom_usb_hsic_phy_power_off,
101 	.owner = THIS_MODULE,
102 };
103 
qcom_usb_hsic_phy_probe(struct ulpi * ulpi)104 static int qcom_usb_hsic_phy_probe(struct ulpi *ulpi)
105 {
106 	struct qcom_usb_hsic_phy *uphy;
107 	struct phy_provider *p;
108 	struct clk *clk;
109 
110 	uphy = devm_kzalloc(&ulpi->dev, sizeof(*uphy), GFP_KERNEL);
111 	if (!uphy)
112 		return -ENOMEM;
113 	ulpi_set_drvdata(ulpi, uphy);
114 
115 	uphy->ulpi = ulpi;
116 	uphy->pctl = devm_pinctrl_get(&ulpi->dev);
117 	if (IS_ERR(uphy->pctl))
118 		return PTR_ERR(uphy->pctl);
119 
120 	uphy->phy_clk = clk = devm_clk_get(&ulpi->dev, "phy");
121 	if (IS_ERR(clk))
122 		return PTR_ERR(clk);
123 
124 	uphy->cal_clk = clk = devm_clk_get(&ulpi->dev, "cal");
125 	if (IS_ERR(clk))
126 		return PTR_ERR(clk);
127 
128 	uphy->cal_sleep_clk = clk = devm_clk_get(&ulpi->dev, "cal_sleep");
129 	if (IS_ERR(clk))
130 		return PTR_ERR(clk);
131 
132 	uphy->phy = devm_phy_create(&ulpi->dev, ulpi->dev.of_node,
133 				    &qcom_usb_hsic_phy_ops);
134 	if (IS_ERR(uphy->phy))
135 		return PTR_ERR(uphy->phy);
136 	phy_set_drvdata(uphy->phy, uphy);
137 
138 	p = devm_of_phy_provider_register(&ulpi->dev, of_phy_simple_xlate);
139 	return PTR_ERR_OR_ZERO(p);
140 }
141 
142 static const struct of_device_id qcom_usb_hsic_phy_match[] = {
143 	{ .compatible = "qcom,usb-hsic-phy", },
144 	{ }
145 };
146 MODULE_DEVICE_TABLE(of, qcom_usb_hsic_phy_match);
147 
148 static struct ulpi_driver qcom_usb_hsic_phy_driver = {
149 	.probe = qcom_usb_hsic_phy_probe,
150 	.driver = {
151 		.name = "qcom_usb_hsic_phy",
152 		.of_match_table = qcom_usb_hsic_phy_match,
153 	},
154 };
155 module_ulpi_driver(qcom_usb_hsic_phy_driver);
156 
157 MODULE_DESCRIPTION("Qualcomm USB HSIC phy");
158 MODULE_LICENSE("GPL v2");
159