1
2
3
4
5
6
7#include <linux/interrupt.h>
8#include <linux/io.h>
9#include <linux/module.h>
10#include <linux/platform_device.h>
11#include <linux/sched.h>
12#include <linux/slab.h>
13
14#include <drm/drm_edid.h>
15
16#include <media/cec.h>
17#include <media/cec-notifier.h>
18
19#include "dw-hdmi-cec.h"
20
21enum {
22 HDMI_IH_CEC_STAT0 = 0x0106,
23 HDMI_IH_MUTE_CEC_STAT0 = 0x0186,
24
25 HDMI_CEC_CTRL = 0x7d00,
26 CEC_CTRL_START = BIT(0),
27 CEC_CTRL_FRAME_TYP = 3 << 1,
28 CEC_CTRL_RETRY = 0 << 1,
29 CEC_CTRL_NORMAL = 1 << 1,
30 CEC_CTRL_IMMED = 2 << 1,
31
32 HDMI_CEC_STAT = 0x7d01,
33 CEC_STAT_DONE = BIT(0),
34 CEC_STAT_EOM = BIT(1),
35 CEC_STAT_NACK = BIT(2),
36 CEC_STAT_ARBLOST = BIT(3),
37 CEC_STAT_ERROR_INIT = BIT(4),
38 CEC_STAT_ERROR_FOLL = BIT(5),
39 CEC_STAT_WAKEUP = BIT(6),
40
41 HDMI_CEC_MASK = 0x7d02,
42 HDMI_CEC_POLARITY = 0x7d03,
43 HDMI_CEC_INT = 0x7d04,
44 HDMI_CEC_ADDR_L = 0x7d05,
45 HDMI_CEC_ADDR_H = 0x7d06,
46 HDMI_CEC_TX_CNT = 0x7d07,
47 HDMI_CEC_RX_CNT = 0x7d08,
48 HDMI_CEC_TX_DATA0 = 0x7d10,
49 HDMI_CEC_RX_DATA0 = 0x7d20,
50 HDMI_CEC_LOCK = 0x7d30,
51 HDMI_CEC_WKUPCTRL = 0x7d31,
52};
53
54struct dw_hdmi_cec {
55 struct dw_hdmi *hdmi;
56 const struct dw_hdmi_cec_ops *ops;
57 u32 addresses;
58 struct cec_adapter *adap;
59 struct cec_msg rx_msg;
60 unsigned int tx_status;
61 bool tx_done;
62 bool rx_done;
63 struct cec_notifier *notify;
64 int irq;
65};
66
67static void dw_hdmi_write(struct dw_hdmi_cec *cec, u8 val, int offset)
68{
69 cec->ops->write(cec->hdmi, val, offset);
70}
71
72static u8 dw_hdmi_read(struct dw_hdmi_cec *cec, int offset)
73{
74 return cec->ops->read(cec->hdmi, offset);
75}
76
77static int dw_hdmi_cec_log_addr(struct cec_adapter *adap, u8 logical_addr)
78{
79 struct dw_hdmi_cec *cec = cec_get_drvdata(adap);
80
81 if (logical_addr == CEC_LOG_ADDR_INVALID)
82 cec->addresses = 0;
83 else
84 cec->addresses |= BIT(logical_addr) | BIT(15);
85
86 dw_hdmi_write(cec, cec->addresses & 255, HDMI_CEC_ADDR_L);
87 dw_hdmi_write(cec, cec->addresses >> 8, HDMI_CEC_ADDR_H);
88
89 return 0;
90}
91
92static int dw_hdmi_cec_transmit(struct cec_adapter *adap, u8 attempts,
93 u32 signal_free_time, struct cec_msg *msg)
94{
95 struct dw_hdmi_cec *cec = cec_get_drvdata(adap);
96 unsigned int i, ctrl;
97
98 switch (signal_free_time) {
99 case CEC_SIGNAL_FREE_TIME_RETRY:
100 ctrl = CEC_CTRL_RETRY;
101 break;
102 case CEC_SIGNAL_FREE_TIME_NEW_INITIATOR:
103 default:
104 ctrl = CEC_CTRL_NORMAL;
105 break;
106 case CEC_SIGNAL_FREE_TIME_NEXT_XFER:
107 ctrl = CEC_CTRL_IMMED;
108 break;
109 }
110
111 for (i = 0; i < msg->len; i++)
112 dw_hdmi_write(cec, msg->msg[i], HDMI_CEC_TX_DATA0 + i);
113
114 dw_hdmi_write(cec, msg->len, HDMI_CEC_TX_CNT);
115 dw_hdmi_write(cec, ctrl | CEC_CTRL_START, HDMI_CEC_CTRL);
116
117 return 0;
118}
119
120static irqreturn_t dw_hdmi_cec_hardirq(int irq, void *data)
121{
122 struct cec_adapter *adap = data;
123 struct dw_hdmi_cec *cec = cec_get_drvdata(adap);
124 unsigned int stat = dw_hdmi_read(cec, HDMI_IH_CEC_STAT0);
125 irqreturn_t ret = IRQ_HANDLED;
126
127 if (stat == 0)
128 return IRQ_NONE;
129
130 dw_hdmi_write(cec, stat, HDMI_IH_CEC_STAT0);
131
132 if (stat & CEC_STAT_ERROR_INIT) {
133 cec->tx_status = CEC_TX_STATUS_ERROR;
134 cec->tx_done = true;
135 ret = IRQ_WAKE_THREAD;
136 } else if (stat & CEC_STAT_DONE) {
137 cec->tx_status = CEC_TX_STATUS_OK;
138 cec->tx_done = true;
139 ret = IRQ_WAKE_THREAD;
140 } else if (stat & CEC_STAT_NACK) {
141 cec->tx_status = CEC_TX_STATUS_NACK;
142 cec->tx_done = true;
143 ret = IRQ_WAKE_THREAD;
144 }
145
146 if (stat & CEC_STAT_EOM) {
147 unsigned int len, i;
148
149 len = dw_hdmi_read(cec, HDMI_CEC_RX_CNT);
150 if (len > sizeof(cec->rx_msg.msg))
151 len = sizeof(cec->rx_msg.msg);
152
153 for (i = 0; i < len; i++)
154 cec->rx_msg.msg[i] =
155 dw_hdmi_read(cec, HDMI_CEC_RX_DATA0 + i);
156
157 dw_hdmi_write(cec, 0, HDMI_CEC_LOCK);
158
159 cec->rx_msg.len = len;
160 smp_wmb();
161 cec->rx_done = true;
162
163 ret = IRQ_WAKE_THREAD;
164 }
165
166 return ret;
167}
168
169static irqreturn_t dw_hdmi_cec_thread(int irq, void *data)
170{
171 struct cec_adapter *adap = data;
172 struct dw_hdmi_cec *cec = cec_get_drvdata(adap);
173
174 if (cec->tx_done) {
175 cec->tx_done = false;
176 cec_transmit_attempt_done(adap, cec->tx_status);
177 }
178 if (cec->rx_done) {
179 cec->rx_done = false;
180 smp_rmb();
181 cec_received_msg(adap, &cec->rx_msg);
182 }
183 return IRQ_HANDLED;
184}
185
186static int dw_hdmi_cec_enable(struct cec_adapter *adap, bool enable)
187{
188 struct dw_hdmi_cec *cec = cec_get_drvdata(adap);
189
190 if (!enable) {
191 dw_hdmi_write(cec, ~0, HDMI_CEC_MASK);
192 dw_hdmi_write(cec, ~0, HDMI_IH_MUTE_CEC_STAT0);
193 dw_hdmi_write(cec, 0, HDMI_CEC_POLARITY);
194
195 cec->ops->disable(cec->hdmi);
196 } else {
197 unsigned int irqs;
198
199 dw_hdmi_write(cec, 0, HDMI_CEC_CTRL);
200 dw_hdmi_write(cec, ~0, HDMI_IH_CEC_STAT0);
201 dw_hdmi_write(cec, 0, HDMI_CEC_LOCK);
202
203 dw_hdmi_cec_log_addr(cec->adap, CEC_LOG_ADDR_INVALID);
204
205 cec->ops->enable(cec->hdmi);
206
207 irqs = CEC_STAT_ERROR_INIT | CEC_STAT_NACK | CEC_STAT_EOM |
208 CEC_STAT_DONE;
209 dw_hdmi_write(cec, irqs, HDMI_CEC_POLARITY);
210 dw_hdmi_write(cec, ~irqs, HDMI_CEC_MASK);
211 dw_hdmi_write(cec, ~irqs, HDMI_IH_MUTE_CEC_STAT0);
212 }
213 return 0;
214}
215
216static const struct cec_adap_ops dw_hdmi_cec_ops = {
217 .adap_enable = dw_hdmi_cec_enable,
218 .adap_log_addr = dw_hdmi_cec_log_addr,
219 .adap_transmit = dw_hdmi_cec_transmit,
220};
221
222static void dw_hdmi_cec_del(void *data)
223{
224 struct dw_hdmi_cec *cec = data;
225
226 cec_delete_adapter(cec->adap);
227}
228
229static int dw_hdmi_cec_probe(struct platform_device *pdev)
230{
231 struct dw_hdmi_cec_data *data = dev_get_platdata(&pdev->dev);
232 struct dw_hdmi_cec *cec;
233 int ret;
234
235 if (!data)
236 return -ENXIO;
237
238
239
240
241
242
243 cec = devm_kzalloc(&pdev->dev, sizeof(*cec), GFP_KERNEL);
244 if (!cec)
245 return -ENOMEM;
246
247 cec->irq = data->irq;
248 cec->ops = data->ops;
249 cec->hdmi = data->hdmi;
250
251 platform_set_drvdata(pdev, cec);
252
253 dw_hdmi_write(cec, 0, HDMI_CEC_TX_CNT);
254 dw_hdmi_write(cec, ~0, HDMI_CEC_MASK);
255 dw_hdmi_write(cec, ~0, HDMI_IH_MUTE_CEC_STAT0);
256 dw_hdmi_write(cec, 0, HDMI_CEC_POLARITY);
257
258 cec->adap = cec_allocate_adapter(&dw_hdmi_cec_ops, cec, "dw_hdmi",
259 CEC_CAP_LOG_ADDRS | CEC_CAP_TRANSMIT |
260 CEC_CAP_RC | CEC_CAP_PASSTHROUGH,
261 CEC_MAX_LOG_ADDRS);
262 if (IS_ERR(cec->adap))
263 return PTR_ERR(cec->adap);
264
265
266 cec->adap->owner = THIS_MODULE;
267
268 ret = devm_add_action(&pdev->dev, dw_hdmi_cec_del, cec);
269 if (ret) {
270 cec_delete_adapter(cec->adap);
271 return ret;
272 }
273
274 ret = devm_request_threaded_irq(&pdev->dev, cec->irq,
275 dw_hdmi_cec_hardirq,
276 dw_hdmi_cec_thread, IRQF_SHARED,
277 "dw-hdmi-cec", cec->adap);
278 if (ret < 0)
279 return ret;
280
281 cec->notify = cec_notifier_get(pdev->dev.parent);
282 if (!cec->notify)
283 return -ENOMEM;
284
285 ret = cec_register_adapter(cec->adap, pdev->dev.parent);
286 if (ret < 0) {
287 cec_notifier_put(cec->notify);
288 return ret;
289 }
290
291
292
293
294
295 devm_remove_action(&pdev->dev, dw_hdmi_cec_del, cec);
296
297 cec_register_cec_notifier(cec->adap, cec->notify);
298
299 return 0;
300}
301
302static int dw_hdmi_cec_remove(struct platform_device *pdev)
303{
304 struct dw_hdmi_cec *cec = platform_get_drvdata(pdev);
305
306 cec_unregister_adapter(cec->adap);
307 cec_notifier_put(cec->notify);
308
309 return 0;
310}
311
312static struct platform_driver dw_hdmi_cec_driver = {
313 .probe = dw_hdmi_cec_probe,
314 .remove = dw_hdmi_cec_remove,
315 .driver = {
316 .name = "dw-hdmi-cec",
317 },
318};
319module_platform_driver(dw_hdmi_cec_driver);
320
321MODULE_AUTHOR("Russell King <rmk+kernel@armlinux.org.uk>");
322MODULE_DESCRIPTION("Synopsys Designware HDMI CEC driver for i.MX");
323MODULE_LICENSE("GPL");
324MODULE_ALIAS(PLATFORM_MODULE_PREFIX "dw-hdmi-cec");
325
