1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright 2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
4 */
5
6 #include <linux/module.h>
7 #include <linux/interrupt.h>
8 #include <linux/delay.h>
9 #include <linux/platform_device.h>
10 #include <linux/gpio/consumer.h>
11 #include <media/cec-notifier.h>
12 #include <media/cec-pin.h>
13
14 struct cec_gpio {
15 struct cec_adapter *adap;
16 struct cec_notifier *notifier;
17 struct device *dev;
18
19 struct gpio_desc *cec_gpio;
20 int cec_irq;
21 bool cec_is_low;
22
23 struct gpio_desc *hpd_gpio;
24 int hpd_irq;
25 bool hpd_is_high;
26 ktime_t hpd_ts;
27
28 struct gpio_desc *v5_gpio;
29 int v5_irq;
30 bool v5_is_high;
31 ktime_t v5_ts;
32 };
33
cec_gpio_read(struct cec_adapter * adap)34 static int cec_gpio_read(struct cec_adapter *adap)
35 {
36 struct cec_gpio *cec = cec_get_drvdata(adap);
37
38 if (cec->cec_is_low)
39 return 0;
40 return gpiod_get_value(cec->cec_gpio);
41 }
42
cec_gpio_high(struct cec_adapter * adap)43 static void cec_gpio_high(struct cec_adapter *adap)
44 {
45 struct cec_gpio *cec = cec_get_drvdata(adap);
46
47 if (!cec->cec_is_low)
48 return;
49 cec->cec_is_low = false;
50 gpiod_set_value(cec->cec_gpio, 1);
51 }
52
cec_gpio_low(struct cec_adapter * adap)53 static void cec_gpio_low(struct cec_adapter *adap)
54 {
55 struct cec_gpio *cec = cec_get_drvdata(adap);
56
57 if (cec->cec_is_low)
58 return;
59 cec->cec_is_low = true;
60 gpiod_set_value(cec->cec_gpio, 0);
61 }
62
cec_hpd_gpio_irq_handler_thread(int irq,void * priv)63 static irqreturn_t cec_hpd_gpio_irq_handler_thread(int irq, void *priv)
64 {
65 struct cec_gpio *cec = priv;
66
67 cec_queue_pin_hpd_event(cec->adap, cec->hpd_is_high, cec->hpd_ts);
68 return IRQ_HANDLED;
69 }
70
cec_5v_gpio_irq_handler(int irq,void * priv)71 static irqreturn_t cec_5v_gpio_irq_handler(int irq, void *priv)
72 {
73 struct cec_gpio *cec = priv;
74 int val = gpiod_get_value(cec->v5_gpio);
75 bool is_high = val > 0;
76
77 if (val < 0 || is_high == cec->v5_is_high)
78 return IRQ_HANDLED;
79 cec->v5_ts = ktime_get();
80 cec->v5_is_high = is_high;
81 return IRQ_WAKE_THREAD;
82 }
83
cec_5v_gpio_irq_handler_thread(int irq,void * priv)84 static irqreturn_t cec_5v_gpio_irq_handler_thread(int irq, void *priv)
85 {
86 struct cec_gpio *cec = priv;
87
88 cec_queue_pin_5v_event(cec->adap, cec->v5_is_high, cec->v5_ts);
89 return IRQ_HANDLED;
90 }
91
cec_hpd_gpio_irq_handler(int irq,void * priv)92 static irqreturn_t cec_hpd_gpio_irq_handler(int irq, void *priv)
93 {
94 struct cec_gpio *cec = priv;
95 int val = gpiod_get_value(cec->hpd_gpio);
96 bool is_high = val > 0;
97
98 if (val < 0 || is_high == cec->hpd_is_high)
99 return IRQ_HANDLED;
100 cec->hpd_ts = ktime_get();
101 cec->hpd_is_high = is_high;
102 return IRQ_WAKE_THREAD;
103 }
104
cec_gpio_irq_handler(int irq,void * priv)105 static irqreturn_t cec_gpio_irq_handler(int irq, void *priv)
106 {
107 struct cec_gpio *cec = priv;
108 int val = gpiod_get_value(cec->cec_gpio);
109
110 if (val >= 0)
111 cec_pin_changed(cec->adap, val > 0);
112 return IRQ_HANDLED;
113 }
114
cec_gpio_enable_irq(struct cec_adapter * adap)115 static bool cec_gpio_enable_irq(struct cec_adapter *adap)
116 {
117 struct cec_gpio *cec = cec_get_drvdata(adap);
118
119 enable_irq(cec->cec_irq);
120 return true;
121 }
122
cec_gpio_disable_irq(struct cec_adapter * adap)123 static void cec_gpio_disable_irq(struct cec_adapter *adap)
124 {
125 struct cec_gpio *cec = cec_get_drvdata(adap);
126
127 disable_irq(cec->cec_irq);
128 }
129
cec_gpio_status(struct cec_adapter * adap,struct seq_file * file)130 static void cec_gpio_status(struct cec_adapter *adap, struct seq_file *file)
131 {
132 struct cec_gpio *cec = cec_get_drvdata(adap);
133
134 seq_printf(file, "mode: %s\n", cec->cec_is_low ? "low-drive" : "read");
135 seq_printf(file, "using irq: %d\n", cec->cec_irq);
136 if (cec->hpd_gpio)
137 seq_printf(file, "hpd: %s\n",
138 cec->hpd_is_high ? "high" : "low");
139 if (cec->v5_gpio)
140 seq_printf(file, "5V: %s\n",
141 cec->v5_is_high ? "high" : "low");
142 }
143
cec_gpio_read_hpd(struct cec_adapter * adap)144 static int cec_gpio_read_hpd(struct cec_adapter *adap)
145 {
146 struct cec_gpio *cec = cec_get_drvdata(adap);
147
148 if (!cec->hpd_gpio)
149 return -ENOTTY;
150 return gpiod_get_value(cec->hpd_gpio);
151 }
152
cec_gpio_read_5v(struct cec_adapter * adap)153 static int cec_gpio_read_5v(struct cec_adapter *adap)
154 {
155 struct cec_gpio *cec = cec_get_drvdata(adap);
156
157 if (!cec->v5_gpio)
158 return -ENOTTY;
159 return gpiod_get_value(cec->v5_gpio);
160 }
161
162 static const struct cec_pin_ops cec_gpio_pin_ops = {
163 .read = cec_gpio_read,
164 .low = cec_gpio_low,
165 .high = cec_gpio_high,
166 .enable_irq = cec_gpio_enable_irq,
167 .disable_irq = cec_gpio_disable_irq,
168 .status = cec_gpio_status,
169 .read_hpd = cec_gpio_read_hpd,
170 .read_5v = cec_gpio_read_5v,
171 };
172
cec_gpio_probe(struct platform_device * pdev)173 static int cec_gpio_probe(struct platform_device *pdev)
174 {
175 struct device *dev = &pdev->dev;
176 struct device *hdmi_dev;
177 struct cec_gpio *cec;
178 u32 caps = CEC_CAP_DEFAULTS | CEC_CAP_MONITOR_ALL | CEC_CAP_MONITOR_PIN;
179 int ret;
180
181 hdmi_dev = cec_notifier_parse_hdmi_phandle(dev);
182 if (PTR_ERR(hdmi_dev) == -EPROBE_DEFER)
183 return PTR_ERR(hdmi_dev);
184 if (IS_ERR(hdmi_dev))
185 caps |= CEC_CAP_PHYS_ADDR;
186
187 cec = devm_kzalloc(dev, sizeof(*cec), GFP_KERNEL);
188 if (!cec)
189 return -ENOMEM;
190
191 cec->dev = dev;
192
193 cec->cec_gpio = devm_gpiod_get(dev, "cec", GPIOD_OUT_HIGH_OPEN_DRAIN);
194 if (IS_ERR(cec->cec_gpio))
195 return PTR_ERR(cec->cec_gpio);
196 cec->cec_irq = gpiod_to_irq(cec->cec_gpio);
197
198 cec->hpd_gpio = devm_gpiod_get_optional(dev, "hpd", GPIOD_IN);
199 if (IS_ERR(cec->hpd_gpio))
200 return PTR_ERR(cec->hpd_gpio);
201
202 cec->v5_gpio = devm_gpiod_get_optional(dev, "v5", GPIOD_IN);
203 if (IS_ERR(cec->v5_gpio))
204 return PTR_ERR(cec->v5_gpio);
205
206 cec->adap = cec_pin_allocate_adapter(&cec_gpio_pin_ops,
207 cec, pdev->name, caps);
208 if (IS_ERR(cec->adap))
209 return PTR_ERR(cec->adap);
210
211 ret = devm_request_irq(dev, cec->cec_irq, cec_gpio_irq_handler,
212 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_NO_AUTOEN,
213 cec->adap->name, cec);
214 if (ret)
215 goto del_adap;
216
217 if (cec->hpd_gpio) {
218 cec->hpd_irq = gpiod_to_irq(cec->hpd_gpio);
219 ret = devm_request_threaded_irq(dev, cec->hpd_irq,
220 cec_hpd_gpio_irq_handler,
221 cec_hpd_gpio_irq_handler_thread,
222 IRQF_ONESHOT |
223 IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
224 "hpd-gpio", cec);
225 if (ret)
226 goto del_adap;
227 }
228
229 if (cec->v5_gpio) {
230 cec->v5_irq = gpiod_to_irq(cec->v5_gpio);
231 ret = devm_request_threaded_irq(dev, cec->v5_irq,
232 cec_5v_gpio_irq_handler,
233 cec_5v_gpio_irq_handler_thread,
234 IRQF_ONESHOT |
235 IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
236 "v5-gpio", cec);
237 if (ret)
238 goto del_adap;
239 }
240
241 if (!IS_ERR(hdmi_dev)) {
242 cec->notifier = cec_notifier_cec_adap_register(hdmi_dev, NULL,
243 cec->adap);
244 if (!cec->notifier) {
245 ret = -ENOMEM;
246 goto del_adap;
247 }
248 }
249
250 ret = cec_register_adapter(cec->adap, &pdev->dev);
251 if (ret)
252 goto unreg_notifier;
253
254 platform_set_drvdata(pdev, cec);
255 return 0;
256
257 unreg_notifier:
258 cec_notifier_cec_adap_unregister(cec->notifier, cec->adap);
259 del_adap:
260 cec_delete_adapter(cec->adap);
261 return ret;
262 }
263
cec_gpio_remove(struct platform_device * pdev)264 static void cec_gpio_remove(struct platform_device *pdev)
265 {
266 struct cec_gpio *cec = platform_get_drvdata(pdev);
267
268 cec_notifier_cec_adap_unregister(cec->notifier, cec->adap);
269 cec_unregister_adapter(cec->adap);
270 }
271
272 static const struct of_device_id cec_gpio_match[] = {
273 {
274 .compatible = "cec-gpio",
275 },
276 {},
277 };
278 MODULE_DEVICE_TABLE(of, cec_gpio_match);
279
280 static struct platform_driver cec_gpio_pdrv = {
281 .probe = cec_gpio_probe,
282 .remove_new = cec_gpio_remove,
283 .driver = {
284 .name = "cec-gpio",
285 .of_match_table = cec_gpio_match,
286 },
287 };
288
289 module_platform_driver(cec_gpio_pdrv);
290
291 MODULE_AUTHOR("Hans Verkuil <hans.verkuil@cisco.com>");
292 MODULE_LICENSE("GPL v2");
293 MODULE_DESCRIPTION("CEC GPIO driver");
294