1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* drivers/media/platform/s5p-cec/s5p_cec.c
3 *
4 * Samsung S5P CEC driver
5 *
6 * Copyright (c) 2014 Samsung Electronics Co., Ltd.
7 *
8 * This driver is based on the "cec interface driver for exynos soc" by
9 * SangPil Moon.
10 */
11
12 #include <linux/clk.h>
13 #include <linux/interrupt.h>
14 #include <linux/kernel.h>
15 #include <linux/mfd/syscon.h>
16 #include <linux/module.h>
17 #include <linux/of.h>
18 #include <linux/of_platform.h>
19 #include <linux/platform_device.h>
20 #include <linux/pm_runtime.h>
21 #include <linux/timer.h>
22 #include <linux/workqueue.h>
23 #include <media/cec.h>
24 #include <media/cec-notifier.h>
25
26 #include "exynos_hdmi_cec.h"
27 #include "regs-cec.h"
28 #include "s5p_cec.h"
29
30 #define CEC_NAME "s5p-cec"
31
32 static int debug;
33 module_param(debug, int, 0644);
34 MODULE_PARM_DESC(debug, "debug level (0-2)");
35
s5p_cec_adap_enable(struct cec_adapter * adap,bool enable)36 static int s5p_cec_adap_enable(struct cec_adapter *adap, bool enable)
37 {
38 int ret;
39 struct s5p_cec_dev *cec = cec_get_drvdata(adap);
40
41 if (enable) {
42 ret = pm_runtime_resume_and_get(cec->dev);
43 if (ret < 0)
44 return ret;
45
46 s5p_cec_reset(cec);
47
48 s5p_cec_set_divider(cec);
49 s5p_cec_threshold(cec);
50
51 s5p_cec_unmask_tx_interrupts(cec);
52 s5p_cec_unmask_rx_interrupts(cec);
53 s5p_cec_enable_rx(cec);
54 } else {
55 s5p_cec_mask_tx_interrupts(cec);
56 s5p_cec_mask_rx_interrupts(cec);
57 pm_runtime_put(cec->dev);
58 }
59
60 return 0;
61 }
62
s5p_cec_adap_log_addr(struct cec_adapter * adap,u8 addr)63 static int s5p_cec_adap_log_addr(struct cec_adapter *adap, u8 addr)
64 {
65 struct s5p_cec_dev *cec = cec_get_drvdata(adap);
66
67 s5p_cec_set_addr(cec, addr);
68 return 0;
69 }
70
s5p_cec_adap_transmit(struct cec_adapter * adap,u8 attempts,u32 signal_free_time,struct cec_msg * msg)71 static int s5p_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
72 u32 signal_free_time, struct cec_msg *msg)
73 {
74 struct s5p_cec_dev *cec = cec_get_drvdata(adap);
75
76 /*
77 * Unclear if 0 retries are allowed by the hardware, so have 1 as
78 * the minimum.
79 */
80 s5p_cec_copy_packet(cec, msg->msg, msg->len, max(1, attempts - 1));
81 return 0;
82 }
83
s5p_cec_irq_handler(int irq,void * priv)84 static irqreturn_t s5p_cec_irq_handler(int irq, void *priv)
85 {
86 struct s5p_cec_dev *cec = priv;
87 u32 status = 0;
88
89 status = s5p_cec_get_status(cec);
90
91 dev_dbg(cec->dev, "irq received\n");
92
93 if (status & CEC_STATUS_TX_DONE) {
94 if (status & CEC_STATUS_TX_NACK) {
95 dev_dbg(cec->dev, "CEC_STATUS_TX_NACK set\n");
96 cec->tx = STATE_NACK;
97 } else if (status & CEC_STATUS_TX_ERROR) {
98 dev_dbg(cec->dev, "CEC_STATUS_TX_ERROR set\n");
99 cec->tx = STATE_ERROR;
100 } else {
101 dev_dbg(cec->dev, "CEC_STATUS_TX_DONE\n");
102 cec->tx = STATE_DONE;
103 }
104 s5p_clr_pending_tx(cec);
105 }
106
107 if (status & CEC_STATUS_RX_DONE) {
108 if (status & CEC_STATUS_RX_ERROR) {
109 dev_dbg(cec->dev, "CEC_STATUS_RX_ERROR set\n");
110 s5p_cec_rx_reset(cec);
111 s5p_cec_enable_rx(cec);
112 } else {
113 dev_dbg(cec->dev, "CEC_STATUS_RX_DONE set\n");
114 if (cec->rx != STATE_IDLE)
115 dev_dbg(cec->dev, "Buffer overrun (worker did not process previous message)\n");
116 cec->rx = STATE_BUSY;
117 cec->msg.len = status >> 24;
118 cec->msg.rx_status = CEC_RX_STATUS_OK;
119 s5p_cec_get_rx_buf(cec, cec->msg.len,
120 cec->msg.msg);
121 cec->rx = STATE_DONE;
122 s5p_cec_enable_rx(cec);
123 }
124 /* Clear interrupt pending bit */
125 s5p_clr_pending_rx(cec);
126 }
127 return IRQ_WAKE_THREAD;
128 }
129
s5p_cec_irq_handler_thread(int irq,void * priv)130 static irqreturn_t s5p_cec_irq_handler_thread(int irq, void *priv)
131 {
132 struct s5p_cec_dev *cec = priv;
133
134 dev_dbg(cec->dev, "irq processing thread\n");
135 switch (cec->tx) {
136 case STATE_DONE:
137 cec_transmit_done(cec->adap, CEC_TX_STATUS_OK, 0, 0, 0, 0);
138 cec->tx = STATE_IDLE;
139 break;
140 case STATE_NACK:
141 cec_transmit_done(cec->adap,
142 CEC_TX_STATUS_MAX_RETRIES | CEC_TX_STATUS_NACK,
143 0, 1, 0, 0);
144 cec->tx = STATE_IDLE;
145 break;
146 case STATE_ERROR:
147 cec_transmit_done(cec->adap,
148 CEC_TX_STATUS_MAX_RETRIES | CEC_TX_STATUS_ERROR,
149 0, 0, 0, 1);
150 cec->tx = STATE_IDLE;
151 break;
152 case STATE_BUSY:
153 dev_err(cec->dev, "state set to busy, this should not occur here\n");
154 break;
155 default:
156 break;
157 }
158
159 switch (cec->rx) {
160 case STATE_DONE:
161 cec_received_msg(cec->adap, &cec->msg);
162 cec->rx = STATE_IDLE;
163 break;
164 default:
165 break;
166 }
167
168 return IRQ_HANDLED;
169 }
170
171 static const struct cec_adap_ops s5p_cec_adap_ops = {
172 .adap_enable = s5p_cec_adap_enable,
173 .adap_log_addr = s5p_cec_adap_log_addr,
174 .adap_transmit = s5p_cec_adap_transmit,
175 };
176
s5p_cec_probe(struct platform_device * pdev)177 static int s5p_cec_probe(struct platform_device *pdev)
178 {
179 struct device *dev = &pdev->dev;
180 struct device *hdmi_dev;
181 struct s5p_cec_dev *cec;
182 bool needs_hpd = of_property_read_bool(pdev->dev.of_node, "needs-hpd");
183 int ret;
184
185 hdmi_dev = cec_notifier_parse_hdmi_phandle(dev);
186
187 if (IS_ERR(hdmi_dev))
188 return PTR_ERR(hdmi_dev);
189
190 cec = devm_kzalloc(&pdev->dev, sizeof(*cec), GFP_KERNEL);
191 if (!cec)
192 return -ENOMEM;
193
194 cec->dev = dev;
195
196 cec->irq = platform_get_irq(pdev, 0);
197 if (cec->irq < 0)
198 return cec->irq;
199
200 ret = devm_request_threaded_irq(dev, cec->irq, s5p_cec_irq_handler,
201 s5p_cec_irq_handler_thread, 0, pdev->name, cec);
202 if (ret)
203 return ret;
204
205 cec->clk = devm_clk_get(dev, "hdmicec");
206 if (IS_ERR(cec->clk))
207 return PTR_ERR(cec->clk);
208
209 cec->pmu = syscon_regmap_lookup_by_phandle(dev->of_node,
210 "samsung,syscon-phandle");
211 if (IS_ERR(cec->pmu))
212 return -EPROBE_DEFER;
213
214 cec->reg = devm_platform_ioremap_resource(pdev, 0);
215 if (IS_ERR(cec->reg))
216 return PTR_ERR(cec->reg);
217
218 cec->adap = cec_allocate_adapter(&s5p_cec_adap_ops, cec, CEC_NAME,
219 CEC_CAP_DEFAULTS | (needs_hpd ? CEC_CAP_NEEDS_HPD : 0) |
220 CEC_CAP_CONNECTOR_INFO, 1);
221 ret = PTR_ERR_OR_ZERO(cec->adap);
222 if (ret)
223 return ret;
224
225 cec->notifier = cec_notifier_cec_adap_register(hdmi_dev, NULL,
226 cec->adap);
227 if (!cec->notifier) {
228 ret = -ENOMEM;
229 goto err_delete_adapter;
230 }
231
232 ret = cec_register_adapter(cec->adap, &pdev->dev);
233 if (ret)
234 goto err_notifier;
235
236 platform_set_drvdata(pdev, cec);
237 pm_runtime_enable(dev);
238
239 dev_dbg(dev, "successfully probed\n");
240 return 0;
241
242 err_notifier:
243 cec_notifier_cec_adap_unregister(cec->notifier, cec->adap);
244
245 err_delete_adapter:
246 cec_delete_adapter(cec->adap);
247 return ret;
248 }
249
s5p_cec_remove(struct platform_device * pdev)250 static int s5p_cec_remove(struct platform_device *pdev)
251 {
252 struct s5p_cec_dev *cec = platform_get_drvdata(pdev);
253
254 cec_notifier_cec_adap_unregister(cec->notifier, cec->adap);
255 cec_unregister_adapter(cec->adap);
256 pm_runtime_disable(&pdev->dev);
257 return 0;
258 }
259
s5p_cec_runtime_suspend(struct device * dev)260 static int __maybe_unused s5p_cec_runtime_suspend(struct device *dev)
261 {
262 struct s5p_cec_dev *cec = dev_get_drvdata(dev);
263
264 clk_disable_unprepare(cec->clk);
265 return 0;
266 }
267
s5p_cec_runtime_resume(struct device * dev)268 static int __maybe_unused s5p_cec_runtime_resume(struct device *dev)
269 {
270 struct s5p_cec_dev *cec = dev_get_drvdata(dev);
271 int ret;
272
273 ret = clk_prepare_enable(cec->clk);
274 if (ret < 0)
275 return ret;
276 return 0;
277 }
278
279 static const struct dev_pm_ops s5p_cec_pm_ops = {
280 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
281 pm_runtime_force_resume)
282 SET_RUNTIME_PM_OPS(s5p_cec_runtime_suspend, s5p_cec_runtime_resume,
283 NULL)
284 };
285
286 static const struct of_device_id s5p_cec_match[] = {
287 {
288 .compatible = "samsung,s5p-cec",
289 },
290 {},
291 };
292 MODULE_DEVICE_TABLE(of, s5p_cec_match);
293
294 static struct platform_driver s5p_cec_pdrv = {
295 .probe = s5p_cec_probe,
296 .remove = s5p_cec_remove,
297 .driver = {
298 .name = CEC_NAME,
299 .of_match_table = s5p_cec_match,
300 .pm = &s5p_cec_pm_ops,
301 },
302 };
303
304 module_platform_driver(s5p_cec_pdrv);
305
306 MODULE_AUTHOR("Kamil Debski <kamil@wypas.org>");
307 MODULE_LICENSE("GPL");
308 MODULE_DESCRIPTION("Samsung S5P CEC driver");
309