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
cec_gpio_free(struct cec_adapter * adap)162 static void cec_gpio_free(struct cec_adapter *adap)
163 {
164 cec_gpio_disable_irq(adap);
165 }
166
167 static const struct cec_pin_ops cec_gpio_pin_ops = {
168 .read = cec_gpio_read,
169 .low = cec_gpio_low,
170 .high = cec_gpio_high,
171 .enable_irq = cec_gpio_enable_irq,
172 .disable_irq = cec_gpio_disable_irq,
173 .status = cec_gpio_status,
174 .free = cec_gpio_free,
175 .read_hpd = cec_gpio_read_hpd,
176 .read_5v = cec_gpio_read_5v,
177 };
178
cec_gpio_probe(struct platform_device * pdev)179 static int cec_gpio_probe(struct platform_device *pdev)
180 {
181 struct device *dev = &pdev->dev;
182 struct device *hdmi_dev;
183 struct cec_gpio *cec;
184 u32 caps = CEC_CAP_DEFAULTS | CEC_CAP_MONITOR_ALL | CEC_CAP_MONITOR_PIN;
185 int ret;
186
187 hdmi_dev = cec_notifier_parse_hdmi_phandle(dev);
188 if (PTR_ERR(hdmi_dev) == -EPROBE_DEFER)
189 return PTR_ERR(hdmi_dev);
190 if (IS_ERR(hdmi_dev))
191 caps |= CEC_CAP_PHYS_ADDR;
192
193 cec = devm_kzalloc(dev, sizeof(*cec), GFP_KERNEL);
194 if (!cec)
195 return -ENOMEM;
196
197 cec->dev = dev;
198
199 cec->cec_gpio = devm_gpiod_get(dev, "cec", GPIOD_OUT_HIGH_OPEN_DRAIN);
200 if (IS_ERR(cec->cec_gpio))
201 return PTR_ERR(cec->cec_gpio);
202 cec->cec_irq = gpiod_to_irq(cec->cec_gpio);
203
204 cec->hpd_gpio = devm_gpiod_get_optional(dev, "hpd", GPIOD_IN);
205 if (IS_ERR(cec->hpd_gpio))
206 return PTR_ERR(cec->hpd_gpio);
207
208 cec->v5_gpio = devm_gpiod_get_optional(dev, "v5", GPIOD_IN);
209 if (IS_ERR(cec->v5_gpio))
210 return PTR_ERR(cec->v5_gpio);
211
212 cec->adap = cec_pin_allocate_adapter(&cec_gpio_pin_ops,
213 cec, pdev->name, caps);
214 if (IS_ERR(cec->adap))
215 return PTR_ERR(cec->adap);
216
217 ret = devm_request_irq(dev, cec->cec_irq, cec_gpio_irq_handler,
218 IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
219 cec->adap->name, cec);
220 if (ret)
221 goto del_adap;
222
223 cec_gpio_disable_irq(cec->adap);
224
225 if (cec->hpd_gpio) {
226 cec->hpd_irq = gpiod_to_irq(cec->hpd_gpio);
227 ret = devm_request_threaded_irq(dev, cec->hpd_irq,
228 cec_hpd_gpio_irq_handler,
229 cec_hpd_gpio_irq_handler_thread,
230 IRQF_ONESHOT |
231 IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
232 "hpd-gpio", cec);
233 if (ret)
234 goto del_adap;
235 }
236
237 if (cec->v5_gpio) {
238 cec->v5_irq = gpiod_to_irq(cec->v5_gpio);
239 ret = devm_request_threaded_irq(dev, cec->v5_irq,
240 cec_5v_gpio_irq_handler,
241 cec_5v_gpio_irq_handler_thread,
242 IRQF_ONESHOT |
243 IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
244 "v5-gpio", cec);
245 if (ret)
246 goto del_adap;
247 }
248
249 if (!IS_ERR(hdmi_dev)) {
250 cec->notifier = cec_notifier_cec_adap_register(hdmi_dev, NULL,
251 cec->adap);
252 if (!cec->notifier) {
253 ret = -ENOMEM;
254 goto del_adap;
255 }
256 }
257
258 ret = cec_register_adapter(cec->adap, &pdev->dev);
259 if (ret)
260 goto unreg_notifier;
261
262 platform_set_drvdata(pdev, cec);
263 return 0;
264
265 unreg_notifier:
266 cec_notifier_cec_adap_unregister(cec->notifier, cec->adap);
267 del_adap:
268 cec_delete_adapter(cec->adap);
269 return ret;
270 }
271
cec_gpio_remove(struct platform_device * pdev)272 static int cec_gpio_remove(struct platform_device *pdev)
273 {
274 struct cec_gpio *cec = platform_get_drvdata(pdev);
275
276 cec_notifier_cec_adap_unregister(cec->notifier, cec->adap);
277 cec_unregister_adapter(cec->adap);
278 return 0;
279 }
280
281 static const struct of_device_id cec_gpio_match[] = {
282 {
283 .compatible = "cec-gpio",
284 },
285 {},
286 };
287 MODULE_DEVICE_TABLE(of, cec_gpio_match);
288
289 static struct platform_driver cec_gpio_pdrv = {
290 .probe = cec_gpio_probe,
291 .remove = cec_gpio_remove,
292 .driver = {
293 .name = "cec-gpio",
294 .of_match_table = cec_gpio_match,
295 },
296 };
297
298 module_platform_driver(cec_gpio_pdrv);
299
300 MODULE_AUTHOR("Hans Verkuil <hans.verkuil@cisco.com>");
301 MODULE_LICENSE("GPL v2");
302 MODULE_DESCRIPTION("CEC GPIO driver");
303