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7#include <linux/clk.h>
8#include <linux/interrupt.h>
9#include <linux/kernel.h>
10#include <linux/mfd/syscon.h>
11#include <linux/module.h>
12#include <linux/of.h>
13#include <linux/of_platform.h>
14#include <linux/platform_device.h>
15
16#include <media/cec.h>
17#include <media/cec-notifier.h>
18
19#define CEC_NAME "stih-cec"
20
21
22#define CEC_CLK_DIV 0x0
23#define CEC_CTRL 0x4
24#define CEC_IRQ_CTRL 0x8
25#define CEC_STATUS 0xC
26#define CEC_EXT_STATUS 0x10
27#define CEC_TX_CTRL 0x14
28#define CEC_FREE_TIME_THRESH 0x18
29#define CEC_BIT_TOUT_THRESH 0x1C
30#define CEC_BIT_PULSE_THRESH 0x20
31#define CEC_DATA 0x24
32#define CEC_TX_ARRAY_CTRL 0x28
33#define CEC_CTRL2 0x2C
34#define CEC_TX_ERROR_STS 0x30
35#define CEC_ADDR_TABLE 0x34
36#define CEC_DATA_ARRAY_CTRL 0x38
37#define CEC_DATA_ARRAY_STATUS 0x3C
38#define CEC_TX_DATA_BASE 0x40
39#define CEC_TX_DATA_TOP 0x50
40#define CEC_TX_DATA_SIZE 0x1
41#define CEC_RX_DATA_BASE 0x54
42#define CEC_RX_DATA_TOP 0x64
43#define CEC_RX_DATA_SIZE 0x1
44
45
46#define CEC_LINE_INACTIVE_EN BIT(0)
47#define CEC_AUTO_BUS_ERR_EN BIT(1)
48#define CEC_STOP_ON_ARB_ERR_EN BIT(2)
49#define CEC_TX_REQ_WAIT_EN BIT(3)
50
51
52#define CEC_TX_ARRAY_EN BIT(0)
53#define CEC_RX_ARRAY_EN BIT(1)
54#define CEC_TX_ARRAY_RESET BIT(2)
55#define CEC_RX_ARRAY_RESET BIT(3)
56#define CEC_TX_N_OF_BYTES_IRQ_EN BIT(4)
57#define CEC_TX_STOP_ON_NACK BIT(7)
58
59
60#define CEC_TX_N_OF_BYTES 0x1F
61#define CEC_TX_START BIT(5)
62#define CEC_TX_AUTO_SOM_EN BIT(6)
63#define CEC_TX_AUTO_EOM_EN BIT(7)
64
65
66#define CEC_TX_DONE_IRQ_EN BIT(0)
67#define CEC_ERROR_IRQ_EN BIT(2)
68#define CEC_RX_DONE_IRQ_EN BIT(3)
69#define CEC_RX_SOM_IRQ_EN BIT(4)
70#define CEC_RX_EOM_IRQ_EN BIT(5)
71#define CEC_FREE_TIME_IRQ_EN BIT(6)
72#define CEC_PIN_STS_IRQ_EN BIT(7)
73
74
75#define CEC_IN_FILTER_EN BIT(0)
76#define CEC_PWR_SAVE_EN BIT(1)
77#define CEC_EN BIT(4)
78#define CEC_ACK_CTRL BIT(5)
79#define CEC_RX_RESET_EN BIT(6)
80#define CEC_IGNORE_RX_ERROR BIT(7)
81
82
83#define CEC_TX_DONE_STS BIT(0)
84#define CEC_TX_ACK_GET_STS BIT(1)
85#define CEC_ERROR_STS BIT(2)
86#define CEC_RX_DONE_STS BIT(3)
87#define CEC_RX_SOM_STS BIT(4)
88#define CEC_RX_EOM_STS BIT(5)
89#define CEC_FREE_TIME_IRQ_STS BIT(6)
90#define CEC_PIN_STS BIT(7)
91#define CEC_SBIT_TOUT_STS BIT(8)
92#define CEC_DBIT_TOUT_STS BIT(9)
93#define CEC_LPULSE_ERROR_STS BIT(10)
94#define CEC_HPULSE_ERROR_STS BIT(11)
95#define CEC_TX_ERROR BIT(12)
96#define CEC_TX_ARB_ERROR BIT(13)
97#define CEC_RX_ERROR_MIN BIT(14)
98#define CEC_RX_ERROR_MAX BIT(15)
99
100
101#define CEC_PRESENT_INIT_SFT 7
102#define CEC_NEW_INIT_SFT 5
103#define CEC_RETRANSMIT_SFT 3
104
105
106#define CEC_SBIT_TOUT_47MS BIT(1)
107#define CEC_SBIT_TOUT_48MS (BIT(0) | BIT(1))
108#define CEC_SBIT_TOUT_50MS BIT(2)
109#define CEC_DBIT_TOUT_27MS BIT(0)
110#define CEC_DBIT_TOUT_28MS BIT(1)
111#define CEC_DBIT_TOUT_29MS (BIT(0) | BIT(1))
112
113
114#define CEC_BIT_LPULSE_03MS BIT(1)
115#define CEC_BIT_HPULSE_03MS BIT(3)
116
117
118#define CEC_RX_N_OF_BYTES 0x1F
119#define CEC_TX_N_OF_BYTES_SENT BIT(5)
120#define CEC_RX_OVERRUN BIT(6)
121
122struct stih_cec {
123 struct cec_adapter *adap;
124 struct device *dev;
125 struct clk *clk;
126 void __iomem *regs;
127 int irq;
128 u32 irq_status;
129 struct cec_notifier *notifier;
130};
131
132static int stih_cec_adap_enable(struct cec_adapter *adap, bool enable)
133{
134 struct stih_cec *cec = cec_get_drvdata(adap);
135
136 if (enable) {
137
138 unsigned long clk_freq = clk_get_rate(cec->clk);
139 u32 cec_clk_div = clk_freq / 10000;
140
141 writel(cec_clk_div, cec->regs + CEC_CLK_DIV);
142
143
144 writel(CEC_SBIT_TOUT_47MS | (CEC_DBIT_TOUT_28MS << 4),
145 cec->regs + CEC_BIT_TOUT_THRESH);
146
147
148 writel(CEC_BIT_LPULSE_03MS | CEC_BIT_HPULSE_03MS,
149 cec->regs + CEC_BIT_PULSE_THRESH);
150
151
152 writel(BIT(5) | BIT(7), cec->regs + CEC_TX_CTRL);
153
154
155 writel(CEC_TX_ARRAY_EN | CEC_RX_ARRAY_EN | CEC_TX_STOP_ON_NACK,
156 cec->regs + CEC_DATA_ARRAY_CTRL);
157
158
159 writel(CEC_IN_FILTER_EN | CEC_EN | CEC_RX_RESET_EN,
160 cec->regs + CEC_CTRL);
161
162
163 writel(0, cec->regs + CEC_ADDR_TABLE);
164
165
166 writel(0x0, cec->regs + CEC_STATUS);
167
168
169 writel(CEC_TX_DONE_IRQ_EN | CEC_RX_DONE_IRQ_EN |
170 CEC_RX_SOM_IRQ_EN | CEC_RX_EOM_IRQ_EN |
171 CEC_ERROR_IRQ_EN,
172 cec->regs + CEC_IRQ_CTRL);
173
174 } else {
175
176 writel(0, cec->regs + CEC_ADDR_TABLE);
177
178
179 writel(0x0, cec->regs + CEC_STATUS);
180
181
182 writel(0, cec->regs + CEC_IRQ_CTRL);
183 }
184
185 return 0;
186}
187
188static int stih_cec_adap_log_addr(struct cec_adapter *adap, u8 logical_addr)
189{
190 struct stih_cec *cec = cec_get_drvdata(adap);
191 u32 reg = readl(cec->regs + CEC_ADDR_TABLE);
192
193 reg |= 1 << logical_addr;
194
195 if (logical_addr == CEC_LOG_ADDR_INVALID)
196 reg = 0;
197
198 writel(reg, cec->regs + CEC_ADDR_TABLE);
199
200 return 0;
201}
202
203static int stih_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
204 u32 signal_free_time, struct cec_msg *msg)
205{
206 struct stih_cec *cec = cec_get_drvdata(adap);
207 int i;
208
209
210 for (i = 0; i < msg->len; i++)
211 writeb(msg->msg[i], cec->regs + CEC_TX_DATA_BASE + i);
212
213
214
215
216
217 writel(CEC_TX_AUTO_SOM_EN | CEC_TX_AUTO_EOM_EN | CEC_TX_START |
218 msg->len, cec->regs + CEC_TX_ARRAY_CTRL);
219
220 return 0;
221}
222
223static void stih_tx_done(struct stih_cec *cec, u32 status)
224{
225 if (status & CEC_TX_ERROR) {
226 cec_transmit_attempt_done(cec->adap, CEC_TX_STATUS_ERROR);
227 return;
228 }
229
230 if (status & CEC_TX_ARB_ERROR) {
231 cec_transmit_attempt_done(cec->adap, CEC_TX_STATUS_ARB_LOST);
232 return;
233 }
234
235 if (!(status & CEC_TX_ACK_GET_STS)) {
236 cec_transmit_attempt_done(cec->adap, CEC_TX_STATUS_NACK);
237 return;
238 }
239
240 cec_transmit_attempt_done(cec->adap, CEC_TX_STATUS_OK);
241}
242
243static void stih_rx_done(struct stih_cec *cec, u32 status)
244{
245 struct cec_msg msg = {};
246 u8 i;
247
248 if (status & CEC_RX_ERROR_MIN)
249 return;
250
251 if (status & CEC_RX_ERROR_MAX)
252 return;
253
254 msg.len = readl(cec->regs + CEC_DATA_ARRAY_STATUS) & 0x1f;
255
256 if (!msg.len)
257 return;
258
259 if (msg.len > 16)
260 msg.len = 16;
261
262 for (i = 0; i < msg.len; i++)
263 msg.msg[i] = readl(cec->regs + CEC_RX_DATA_BASE + i);
264
265 cec_received_msg(cec->adap, &msg);
266}
267
268static irqreturn_t stih_cec_irq_handler_thread(int irq, void *priv)
269{
270 struct stih_cec *cec = priv;
271
272 if (cec->irq_status & CEC_TX_DONE_STS)
273 stih_tx_done(cec, cec->irq_status);
274
275 if (cec->irq_status & CEC_RX_DONE_STS)
276 stih_rx_done(cec, cec->irq_status);
277
278 cec->irq_status = 0;
279
280 return IRQ_HANDLED;
281}
282
283static irqreturn_t stih_cec_irq_handler(int irq, void *priv)
284{
285 struct stih_cec *cec = priv;
286
287 cec->irq_status = readl(cec->regs + CEC_STATUS);
288 writel(cec->irq_status, cec->regs + CEC_STATUS);
289
290 return IRQ_WAKE_THREAD;
291}
292
293static const struct cec_adap_ops sti_cec_adap_ops = {
294 .adap_enable = stih_cec_adap_enable,
295 .adap_log_addr = stih_cec_adap_log_addr,
296 .adap_transmit = stih_cec_adap_transmit,
297};
298
299static int stih_cec_probe(struct platform_device *pdev)
300{
301 struct device *dev = &pdev->dev;
302 struct resource *res;
303 struct stih_cec *cec;
304 struct device_node *np;
305 struct platform_device *hdmi_dev;
306 int ret;
307
308 cec = devm_kzalloc(dev, sizeof(*cec), GFP_KERNEL);
309 if (!cec)
310 return -ENOMEM;
311
312 np = of_parse_phandle(pdev->dev.of_node, "hdmi-phandle", 0);
313
314 if (!np) {
315 dev_err(&pdev->dev, "Failed to find hdmi node in device tree\n");
316 return -ENODEV;
317 }
318
319 hdmi_dev = of_find_device_by_node(np);
320 if (!hdmi_dev)
321 return -EPROBE_DEFER;
322
323 cec->notifier = cec_notifier_get(&hdmi_dev->dev);
324 if (!cec->notifier)
325 return -ENOMEM;
326
327 cec->dev = dev;
328
329 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
330 cec->regs = devm_ioremap_resource(dev, res);
331 if (IS_ERR(cec->regs))
332 return PTR_ERR(cec->regs);
333
334 cec->irq = platform_get_irq(pdev, 0);
335 if (cec->irq < 0)
336 return cec->irq;
337
338 ret = devm_request_threaded_irq(dev, cec->irq, stih_cec_irq_handler,
339 stih_cec_irq_handler_thread, 0,
340 pdev->name, cec);
341 if (ret)
342 return ret;
343
344 cec->clk = devm_clk_get(dev, "cec-clk");
345 if (IS_ERR(cec->clk)) {
346 dev_err(dev, "Cannot get cec clock\n");
347 return PTR_ERR(cec->clk);
348 }
349
350 cec->adap = cec_allocate_adapter(&sti_cec_adap_ops, cec,
351 CEC_NAME, CEC_CAP_DEFAULTS, CEC_MAX_LOG_ADDRS);
352 ret = PTR_ERR_OR_ZERO(cec->adap);
353 if (ret)
354 return ret;
355
356 ret = cec_register_adapter(cec->adap, &pdev->dev);
357 if (ret) {
358 cec_delete_adapter(cec->adap);
359 return ret;
360 }
361
362 cec_register_cec_notifier(cec->adap, cec->notifier);
363
364 platform_set_drvdata(pdev, cec);
365 return 0;
366}
367
368static int stih_cec_remove(struct platform_device *pdev)
369{
370 struct stih_cec *cec = platform_get_drvdata(pdev);
371
372 cec_unregister_adapter(cec->adap);
373 cec_notifier_put(cec->notifier);
374
375 return 0;
376}
377
378static const struct of_device_id stih_cec_match[] = {
379 {
380 .compatible = "st,stih-cec",
381 },
382 {},
383};
384MODULE_DEVICE_TABLE(of, stih_cec_match);
385
386static struct platform_driver stih_cec_pdrv = {
387 .probe = stih_cec_probe,
388 .remove = stih_cec_remove,
389 .driver = {
390 .name = CEC_NAME,
391 .of_match_table = stih_cec_match,
392 },
393};
394
395module_platform_driver(stih_cec_pdrv);
396
397MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@linaro.org>");
398MODULE_LICENSE("GPL");
399MODULE_DESCRIPTION("STIH4xx CEC driver");
400
