1 // SPDX-License-Identifier: GPL-2.0-only
3 * Designware HDMI CEC driver
5 * Copyright (C) 2015-2017 Russell King.
7 #include <linux/interrupt.h>
9 #include <linux/module.h>
10 #include <linux/platform_device.h>
11 #include <linux/sched.h>
12 #include <linux/slab.h>
14 #include <drm/drm_edid.h>
16 #include <media/cec.h>
17 #include <media/cec-notifier.h>
19 #include "dw-hdmi-cec.h"
22 HDMI_IH_CEC_STAT0 = 0x0106,
23 HDMI_IH_MUTE_CEC_STAT0 = 0x0186,
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,
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),
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,
56 const struct dw_hdmi_cec_ops *ops;
58 struct cec_adapter *adap;
59 struct cec_msg rx_msg;
60 unsigned int tx_status;
63 struct cec_notifier *notify;
67 static void dw_hdmi_write(struct dw_hdmi_cec *cec, u8 val, int offset)
69 cec->ops->write(cec->hdmi, val, offset);
72 static u8 dw_hdmi_read(struct dw_hdmi_cec *cec, int offset)
74 return cec->ops->read(cec->hdmi, offset);
77 static int dw_hdmi_cec_log_addr(struct cec_adapter *adap, u8 logical_addr)
79 struct dw_hdmi_cec *cec = cec_get_drvdata(adap);
81 if (logical_addr == CEC_LOG_ADDR_INVALID)
84 cec->addresses |= BIT(logical_addr) | BIT(15);
86 dw_hdmi_write(cec, cec->addresses & 255, HDMI_CEC_ADDR_L);
87 dw_hdmi_write(cec, cec->addresses >> 8, HDMI_CEC_ADDR_H);
92 static int dw_hdmi_cec_transmit(struct cec_adapter *adap, u8 attempts,
93 u32 signal_free_time, struct cec_msg *msg)
95 struct dw_hdmi_cec *cec = cec_get_drvdata(adap);
98 switch (signal_free_time) {
99 case CEC_SIGNAL_FREE_TIME_RETRY:
100 ctrl = CEC_CTRL_RETRY;
102 case CEC_SIGNAL_FREE_TIME_NEW_INITIATOR:
104 ctrl = CEC_CTRL_NORMAL;
106 case CEC_SIGNAL_FREE_TIME_NEXT_XFER:
107 ctrl = CEC_CTRL_IMMED;
111 for (i = 0; i < msg->len; i++)
112 dw_hdmi_write(cec, msg->msg[i], HDMI_CEC_TX_DATA0 + i);
114 dw_hdmi_write(cec, msg->len, HDMI_CEC_TX_CNT);
115 dw_hdmi_write(cec, ctrl | CEC_CTRL_START, HDMI_CEC_CTRL);
120 static irqreturn_t dw_hdmi_cec_hardirq(int irq, void *data)
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;
130 dw_hdmi_write(cec, stat, HDMI_IH_CEC_STAT0);
132 if (stat & CEC_STAT_ERROR_INIT) {
133 cec->tx_status = CEC_TX_STATUS_ERROR;
135 ret = IRQ_WAKE_THREAD;
136 } else if (stat & CEC_STAT_DONE) {
137 cec->tx_status = CEC_TX_STATUS_OK;
139 ret = IRQ_WAKE_THREAD;
140 } else if (stat & CEC_STAT_NACK) {
141 cec->tx_status = CEC_TX_STATUS_NACK;
143 ret = IRQ_WAKE_THREAD;
146 if (stat & CEC_STAT_EOM) {
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);
153 for (i = 0; i < len; i++)
155 dw_hdmi_read(cec, HDMI_CEC_RX_DATA0 + i);
157 dw_hdmi_write(cec, 0, HDMI_CEC_LOCK);
159 cec->rx_msg.len = len;
163 ret = IRQ_WAKE_THREAD;
169 static irqreturn_t dw_hdmi_cec_thread(int irq, void *data)
171 struct cec_adapter *adap = data;
172 struct dw_hdmi_cec *cec = cec_get_drvdata(adap);
175 cec->tx_done = false;
176 cec_transmit_attempt_done(adap, cec->tx_status);
179 cec->rx_done = false;
181 cec_received_msg(adap, &cec->rx_msg);
186 static int dw_hdmi_cec_enable(struct cec_adapter *adap, bool enable)
188 struct dw_hdmi_cec *cec = cec_get_drvdata(adap);
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);
195 cec->ops->disable(cec->hdmi);
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);
203 dw_hdmi_cec_log_addr(cec->adap, CEC_LOG_ADDR_INVALID);
205 cec->ops->enable(cec->hdmi);
207 irqs = CEC_STAT_ERROR_INIT | CEC_STAT_NACK | CEC_STAT_EOM |
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);
216 static 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,
222 static void dw_hdmi_cec_del(void *data)
224 struct dw_hdmi_cec *cec = data;
226 cec_delete_adapter(cec->adap);
229 static int dw_hdmi_cec_probe(struct platform_device *pdev)
231 struct dw_hdmi_cec_data *data = dev_get_platdata(&pdev->dev);
232 struct dw_hdmi_cec *cec;
239 * Our device is just a convenience - we want to link to the real
240 * hardware device here, so that userspace can see the association
241 * between the HDMI hardware and its associated CEC chardev.
243 cec = devm_kzalloc(&pdev->dev, sizeof(*cec), GFP_KERNEL);
247 cec->irq = data->irq;
248 cec->ops = data->ops;
249 cec->hdmi = data->hdmi;
251 platform_set_drvdata(pdev, cec);
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);
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,
262 if (IS_ERR(cec->adap))
263 return PTR_ERR(cec->adap);
265 /* override the module pointer */
266 cec->adap->owner = THIS_MODULE;
268 ret = devm_add_action(&pdev->dev, dw_hdmi_cec_del, cec);
270 cec_delete_adapter(cec->adap);
274 ret = devm_request_threaded_irq(&pdev->dev, cec->irq,
276 dw_hdmi_cec_thread, IRQF_SHARED,
277 "dw-hdmi-cec", cec->adap);
281 cec->notify = cec_notifier_get(pdev->dev.parent);
285 ret = cec_register_adapter(cec->adap, pdev->dev.parent);
287 cec_notifier_put(cec->notify);
292 * CEC documentation says we must not call cec_delete_adapter
293 * after a successful call to cec_register_adapter().
295 devm_remove_action(&pdev->dev, dw_hdmi_cec_del, cec);
297 cec_register_cec_notifier(cec->adap, cec->notify);
302 static int dw_hdmi_cec_remove(struct platform_device *pdev)
304 struct dw_hdmi_cec *cec = platform_get_drvdata(pdev);
306 cec_unregister_adapter(cec->adap);
307 cec_notifier_put(cec->notify);
312 static struct platform_driver dw_hdmi_cec_driver = {
313 .probe = dw_hdmi_cec_probe,
314 .remove = dw_hdmi_cec_remove,
316 .name = "dw-hdmi-cec",
319 module_platform_driver(dw_hdmi_cec_driver);
321 MODULE_AUTHOR("Russell King <rmk+kernel@armlinux.org.uk>");
322 MODULE_DESCRIPTION("Synopsys Designware HDMI CEC driver for i.MX");
323 MODULE_LICENSE("GPL");
324 MODULE_ALIAS(PLATFORM_MODULE_PREFIX "dw-hdmi-cec");