1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Copyright (c) 2015-2021, The Linux Foundation. All rights reserved. |
4 | */ |
5 | |
6 | #include <linux/bitops.h> |
7 | #include <linux/err.h> |
8 | #include <linux/interrupt.h> |
9 | #include <linux/io.h> |
10 | #include <linux/iopoll.h> |
11 | #include <linux/kernel.h> |
12 | #include <linux/module.h> |
13 | #include <linux/of.h> |
14 | #include <linux/platform_device.h> |
15 | #include <linux/slab.h> |
16 | #include <linux/sysfs.h> |
17 | #include <linux/usb/role.h> |
18 | |
19 | #define EUD_REG_INT1_EN_MASK 0x0024 |
20 | #define EUD_REG_INT_STATUS_1 0x0044 |
21 | #define EUD_REG_CTL_OUT_1 0x0074 |
22 | #define EUD_REG_VBUS_INT_CLR 0x0080 |
23 | #define EUD_REG_CSR_EUD_EN 0x1014 |
24 | #define EUD_REG_SW_ATTACH_DET 0x1018 |
25 | #define EUD_REG_EUD_EN2 0x0000 |
26 | |
27 | #define EUD_ENABLE BIT(0) |
28 | #define EUD_INT_PET_EUD BIT(0) |
29 | #define EUD_INT_VBUS BIT(2) |
30 | #define EUD_INT_SAFE_MODE BIT(4) |
31 | #define EUD_INT_ALL (EUD_INT_VBUS | EUD_INT_SAFE_MODE) |
32 | |
33 | struct eud_chip { |
34 | struct device *dev; |
35 | struct usb_role_switch *role_sw; |
36 | void __iomem *base; |
37 | void __iomem *mode_mgr; |
38 | unsigned int int_status; |
39 | int irq; |
40 | bool enabled; |
41 | bool usb_attached; |
42 | }; |
43 | |
44 | static int enable_eud(struct eud_chip *priv) |
45 | { |
46 | writel(EUD_ENABLE, addr: priv->base + EUD_REG_CSR_EUD_EN); |
47 | writel(EUD_INT_VBUS | EUD_INT_SAFE_MODE, |
48 | addr: priv->base + EUD_REG_INT1_EN_MASK); |
49 | writel(val: 1, addr: priv->mode_mgr + EUD_REG_EUD_EN2); |
50 | |
51 | return usb_role_switch_set_role(sw: priv->role_sw, role: USB_ROLE_DEVICE); |
52 | } |
53 | |
54 | static void disable_eud(struct eud_chip *priv) |
55 | { |
56 | writel(val: 0, addr: priv->base + EUD_REG_CSR_EUD_EN); |
57 | writel(val: 0, addr: priv->mode_mgr + EUD_REG_EUD_EN2); |
58 | } |
59 | |
60 | static ssize_t enable_show(struct device *dev, |
61 | struct device_attribute *attr, char *buf) |
62 | { |
63 | struct eud_chip *chip = dev_get_drvdata(dev); |
64 | |
65 | return sysfs_emit(buf, fmt: "%d\n" , chip->enabled); |
66 | } |
67 | |
68 | static ssize_t enable_store(struct device *dev, |
69 | struct device_attribute *attr, |
70 | const char *buf, size_t count) |
71 | { |
72 | struct eud_chip *chip = dev_get_drvdata(dev); |
73 | bool enable; |
74 | int ret; |
75 | |
76 | if (kstrtobool(s: buf, res: &enable)) |
77 | return -EINVAL; |
78 | |
79 | if (enable) { |
80 | ret = enable_eud(priv: chip); |
81 | if (!ret) |
82 | chip->enabled = enable; |
83 | else |
84 | disable_eud(priv: chip); |
85 | } else { |
86 | disable_eud(priv: chip); |
87 | } |
88 | |
89 | return count; |
90 | } |
91 | |
92 | static DEVICE_ATTR_RW(enable); |
93 | |
94 | static struct attribute *eud_attrs[] = { |
95 | &dev_attr_enable.attr, |
96 | NULL, |
97 | }; |
98 | ATTRIBUTE_GROUPS(eud); |
99 | |
100 | static void usb_attach_detach(struct eud_chip *chip) |
101 | { |
102 | u32 reg; |
103 | |
104 | /* read ctl_out_1[4] to find USB attach or detach event */ |
105 | reg = readl(addr: chip->base + EUD_REG_CTL_OUT_1); |
106 | chip->usb_attached = reg & EUD_INT_SAFE_MODE; |
107 | } |
108 | |
109 | static void pet_eud(struct eud_chip *chip) |
110 | { |
111 | u32 reg; |
112 | int ret; |
113 | |
114 | /* When the EUD_INT_PET_EUD in SW_ATTACH_DET is set, the cable has been |
115 | * disconnected and we need to detach the pet to check if EUD is in safe |
116 | * mode before attaching again. |
117 | */ |
118 | reg = readl(addr: chip->base + EUD_REG_SW_ATTACH_DET); |
119 | if (reg & EUD_INT_PET_EUD) { |
120 | /* Detach & Attach pet for EUD */ |
121 | writel(val: 0, addr: chip->base + EUD_REG_SW_ATTACH_DET); |
122 | /* Delay to make sure detach pet is done before attach pet */ |
123 | ret = readl_poll_timeout(chip->base + EUD_REG_SW_ATTACH_DET, |
124 | reg, (reg == 0), 1, 100); |
125 | if (ret) { |
126 | dev_err(chip->dev, "Detach pet failed\n" ); |
127 | return; |
128 | } |
129 | } |
130 | /* Attach pet for EUD */ |
131 | writel(EUD_INT_PET_EUD, addr: chip->base + EUD_REG_SW_ATTACH_DET); |
132 | } |
133 | |
134 | static irqreturn_t handle_eud_irq(int irq, void *data) |
135 | { |
136 | struct eud_chip *chip = data; |
137 | u32 reg; |
138 | |
139 | reg = readl(addr: chip->base + EUD_REG_INT_STATUS_1); |
140 | switch (reg & EUD_INT_ALL) { |
141 | case EUD_INT_VBUS: |
142 | usb_attach_detach(chip); |
143 | return IRQ_WAKE_THREAD; |
144 | case EUD_INT_SAFE_MODE: |
145 | pet_eud(chip); |
146 | return IRQ_HANDLED; |
147 | default: |
148 | return IRQ_NONE; |
149 | } |
150 | } |
151 | |
152 | static irqreturn_t handle_eud_irq_thread(int irq, void *data) |
153 | { |
154 | struct eud_chip *chip = data; |
155 | int ret; |
156 | |
157 | if (chip->usb_attached) |
158 | ret = usb_role_switch_set_role(sw: chip->role_sw, role: USB_ROLE_DEVICE); |
159 | else |
160 | ret = usb_role_switch_set_role(sw: chip->role_sw, role: USB_ROLE_HOST); |
161 | if (ret) |
162 | dev_err(chip->dev, "failed to set role switch\n" ); |
163 | |
164 | /* set and clear vbus_int_clr[0] to clear interrupt */ |
165 | writel(BIT(0), addr: chip->base + EUD_REG_VBUS_INT_CLR); |
166 | writel(val: 0, addr: chip->base + EUD_REG_VBUS_INT_CLR); |
167 | |
168 | return IRQ_HANDLED; |
169 | } |
170 | |
171 | static void eud_role_switch_release(void *data) |
172 | { |
173 | struct eud_chip *chip = data; |
174 | |
175 | usb_role_switch_put(sw: chip->role_sw); |
176 | } |
177 | |
178 | static int eud_probe(struct platform_device *pdev) |
179 | { |
180 | struct eud_chip *chip; |
181 | int ret; |
182 | |
183 | chip = devm_kzalloc(dev: &pdev->dev, size: sizeof(*chip), GFP_KERNEL); |
184 | if (!chip) |
185 | return -ENOMEM; |
186 | |
187 | chip->dev = &pdev->dev; |
188 | |
189 | chip->role_sw = usb_role_switch_get(dev: &pdev->dev); |
190 | if (IS_ERR(ptr: chip->role_sw)) |
191 | return dev_err_probe(dev: chip->dev, err: PTR_ERR(ptr: chip->role_sw), |
192 | fmt: "failed to get role switch\n" ); |
193 | |
194 | ret = devm_add_action_or_reset(chip->dev, eud_role_switch_release, chip); |
195 | if (ret) |
196 | return dev_err_probe(dev: chip->dev, err: ret, |
197 | fmt: "failed to add role switch release action\n" ); |
198 | |
199 | chip->base = devm_platform_ioremap_resource(pdev, index: 0); |
200 | if (IS_ERR(ptr: chip->base)) |
201 | return PTR_ERR(ptr: chip->base); |
202 | |
203 | chip->mode_mgr = devm_platform_ioremap_resource(pdev, index: 1); |
204 | if (IS_ERR(ptr: chip->mode_mgr)) |
205 | return PTR_ERR(ptr: chip->mode_mgr); |
206 | |
207 | chip->irq = platform_get_irq(pdev, 0); |
208 | if (chip->irq < 0) |
209 | return chip->irq; |
210 | |
211 | ret = devm_request_threaded_irq(dev: &pdev->dev, irq: chip->irq, handler: handle_eud_irq, |
212 | thread_fn: handle_eud_irq_thread, IRQF_ONESHOT, NULL, dev_id: chip); |
213 | if (ret) |
214 | return dev_err_probe(dev: chip->dev, err: ret, fmt: "failed to allocate irq\n" ); |
215 | |
216 | enable_irq_wake(irq: chip->irq); |
217 | |
218 | platform_set_drvdata(pdev, data: chip); |
219 | |
220 | return 0; |
221 | } |
222 | |
223 | static void eud_remove(struct platform_device *pdev) |
224 | { |
225 | struct eud_chip *chip = platform_get_drvdata(pdev); |
226 | |
227 | if (chip->enabled) |
228 | disable_eud(priv: chip); |
229 | |
230 | device_init_wakeup(dev: &pdev->dev, enable: false); |
231 | disable_irq_wake(irq: chip->irq); |
232 | } |
233 | |
234 | static const struct of_device_id eud_dt_match[] = { |
235 | { .compatible = "qcom,sc7280-eud" }, |
236 | { } |
237 | }; |
238 | MODULE_DEVICE_TABLE(of, eud_dt_match); |
239 | |
240 | static struct platform_driver eud_driver = { |
241 | .probe = eud_probe, |
242 | .remove_new = eud_remove, |
243 | .driver = { |
244 | .name = "qcom_eud" , |
245 | .dev_groups = eud_groups, |
246 | .of_match_table = eud_dt_match, |
247 | }, |
248 | }; |
249 | module_platform_driver(eud_driver); |
250 | |
251 | MODULE_DESCRIPTION("QTI EUD driver" ); |
252 | MODULE_LICENSE("GPL v2" ); |
253 | |