1 /*
2 * Copyright (C) 2013 STMicroelectronics Limited
3 * Author: Srinivas Kandagatla <srinivas.kandagatla@st.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 */
10 #include <linux/kernel.h>
11 #include <linux/clk.h>
12 #include <linux/interrupt.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/platform_device.h>
16 #include <linux/reset.h>
17 #include <media/rc-core.h>
18 #include <linux/pinctrl/consumer.h>
19 #include <linux/pm_wakeirq.h>
20
21 struct st_rc_device {
22 struct device *dev;
23 int irq;
24 int irq_wake;
25 struct clk *sys_clock;
26 void __iomem *base; /* Register base address */
27 void __iomem *rx_base;/* RX Register base address */
28 struct rc_dev *rdev;
29 bool overclocking;
30 int sample_mult;
31 int sample_div;
32 bool rxuhfmode;
33 struct reset_control *rstc;
34 };
35
36 /* Registers */
37 #define IRB_SAMPLE_RATE_COMM 0x64 /* sample freq divisor*/
38 #define IRB_CLOCK_SEL 0x70 /* clock select */
39 #define IRB_CLOCK_SEL_STATUS 0x74 /* clock status */
40 /* IRB IR/UHF receiver registers */
41 #define IRB_RX_ON 0x40 /* pulse time capture */
42 #define IRB_RX_SYS 0X44 /* sym period capture */
43 #define IRB_RX_INT_EN 0x48 /* IRQ enable (R/W) */
44 #define IRB_RX_INT_STATUS 0x4c /* IRQ status (R/W) */
45 #define IRB_RX_EN 0x50 /* Receive enable */
46 #define IRB_MAX_SYM_PERIOD 0x54 /* max sym value */
47 #define IRB_RX_INT_CLEAR 0x58 /* overrun status */
48 #define IRB_RX_STATUS 0x6c /* receive status */
49 #define IRB_RX_NOISE_SUPPR 0x5c /* noise suppression */
50 #define IRB_RX_POLARITY_INV 0x68 /* polarity inverter */
51
52 /*
53 * IRQ set: Enable full FIFO 1 -> bit 3;
54 * Enable overrun IRQ 1 -> bit 2;
55 * Enable last symbol IRQ 1 -> bit 1:
56 * Enable RX interrupt 1 -> bit 0;
57 */
58 #define IRB_RX_INTS 0x0f
59 #define IRB_RX_OVERRUN_INT 0x04
60 /* maximum symbol period (microsecs),timeout to detect end of symbol train */
61 #define MAX_SYMB_TIME 0x5000
62 #define IRB_SAMPLE_FREQ 10000000
63 #define IRB_FIFO_NOT_EMPTY 0xff00
64 #define IRB_OVERFLOW 0x4
65 #define IRB_TIMEOUT 0xffff
66 #define IR_ST_NAME "st-rc"
67
st_rc_send_lirc_timeout(struct rc_dev * rdev)68 static void st_rc_send_lirc_timeout(struct rc_dev *rdev)
69 {
70 DEFINE_IR_RAW_EVENT(ev);
71 ev.timeout = true;
72 ir_raw_event_store(rdev, &ev);
73 }
74
75 /*
76 * RX graphical example to better understand the difference between ST IR block
77 * output and standard definition used by LIRC (and most of the world!)
78 *
79 * mark mark
80 * |-IRB_RX_ON-| |-IRB_RX_ON-|
81 * ___ ___ ___ ___ ___ ___ _
82 * | | | | | | | | | | | | |
83 * | | | | | | space 0 | | | | | | space 1 |
84 * _____| |__| |__| |____________________________| |__| |__| |_____________|
85 *
86 * |--------------- IRB_RX_SYS -------------|------ IRB_RX_SYS -------|
87 *
88 * |------------- encoding bit 0 -----------|---- encoding bit 1 -----|
89 *
90 * ST hardware returns mark (IRB_RX_ON) and total symbol time (IRB_RX_SYS), so
91 * convert to standard mark/space we have to calculate space=(IRB_RX_SYS-mark)
92 * The mark time represents the amount of time the carrier (usually 36-40kHz)
93 * is detected.The above examples shows Pulse Width Modulation encoding where
94 * bit 0 is represented by space>mark.
95 */
96
st_rc_rx_interrupt(int irq,void * data)97 static irqreturn_t st_rc_rx_interrupt(int irq, void *data)
98 {
99 unsigned long timeout;
100 unsigned int symbol, mark = 0;
101 struct st_rc_device *dev = data;
102 int last_symbol = 0;
103 u32 status, int_status;
104 DEFINE_IR_RAW_EVENT(ev);
105
106 if (dev->irq_wake)
107 pm_wakeup_event(dev->dev, 0);
108
109 /* FIXME: is 10ms good enough ? */
110 timeout = jiffies + msecs_to_jiffies(10);
111 do {
112 status = readl(dev->rx_base + IRB_RX_STATUS);
113 if (!(status & (IRB_FIFO_NOT_EMPTY | IRB_OVERFLOW)))
114 break;
115
116 int_status = readl(dev->rx_base + IRB_RX_INT_STATUS);
117 if (unlikely(int_status & IRB_RX_OVERRUN_INT)) {
118 /* discard the entire collection in case of errors! */
119 ir_raw_event_reset(dev->rdev);
120 dev_info(dev->dev, "IR RX overrun\n");
121 writel(IRB_RX_OVERRUN_INT,
122 dev->rx_base + IRB_RX_INT_CLEAR);
123 continue;
124 }
125
126 symbol = readl(dev->rx_base + IRB_RX_SYS);
127 mark = readl(dev->rx_base + IRB_RX_ON);
128
129 if (symbol == IRB_TIMEOUT)
130 last_symbol = 1;
131
132 /* Ignore any noise */
133 if ((mark > 2) && (symbol > 1)) {
134 symbol -= mark;
135 if (dev->overclocking) { /* adjustments to timings */
136 symbol *= dev->sample_mult;
137 symbol /= dev->sample_div;
138 mark *= dev->sample_mult;
139 mark /= dev->sample_div;
140 }
141
142 ev.duration = US_TO_NS(mark);
143 ev.pulse = true;
144 ir_raw_event_store(dev->rdev, &ev);
145
146 if (!last_symbol) {
147 ev.duration = US_TO_NS(symbol);
148 ev.pulse = false;
149 ir_raw_event_store(dev->rdev, &ev);
150 } else {
151 st_rc_send_lirc_timeout(dev->rdev);
152 }
153
154 }
155 last_symbol = 0;
156 } while (time_is_after_jiffies(timeout));
157
158 writel(IRB_RX_INTS, dev->rx_base + IRB_RX_INT_CLEAR);
159
160 /* Empty software fifo */
161 ir_raw_event_handle(dev->rdev);
162 return IRQ_HANDLED;
163 }
164
st_rc_hardware_init(struct st_rc_device * dev)165 static void st_rc_hardware_init(struct st_rc_device *dev)
166 {
167 int baseclock, freqdiff;
168 unsigned int rx_max_symbol_per = MAX_SYMB_TIME;
169 unsigned int rx_sampling_freq_div;
170
171 /* Enable the IP */
172 reset_control_deassert(dev->rstc);
173
174 clk_prepare_enable(dev->sys_clock);
175 baseclock = clk_get_rate(dev->sys_clock);
176
177 /* IRB input pins are inverted internally from high to low. */
178 writel(1, dev->rx_base + IRB_RX_POLARITY_INV);
179
180 rx_sampling_freq_div = baseclock / IRB_SAMPLE_FREQ;
181 writel(rx_sampling_freq_div, dev->base + IRB_SAMPLE_RATE_COMM);
182
183 freqdiff = baseclock - (rx_sampling_freq_div * IRB_SAMPLE_FREQ);
184 if (freqdiff) { /* over clocking, workout the adjustment factors */
185 dev->overclocking = true;
186 dev->sample_mult = 1000;
187 dev->sample_div = baseclock / (10000 * rx_sampling_freq_div);
188 rx_max_symbol_per = (rx_max_symbol_per * 1000)/dev->sample_div;
189 }
190
191 writel(rx_max_symbol_per, dev->rx_base + IRB_MAX_SYM_PERIOD);
192 }
193
st_rc_remove(struct platform_device * pdev)194 static int st_rc_remove(struct platform_device *pdev)
195 {
196 struct st_rc_device *rc_dev = platform_get_drvdata(pdev);
197
198 dev_pm_clear_wake_irq(&pdev->dev);
199 device_init_wakeup(&pdev->dev, false);
200 clk_disable_unprepare(rc_dev->sys_clock);
201 rc_unregister_device(rc_dev->rdev);
202 return 0;
203 }
204
st_rc_open(struct rc_dev * rdev)205 static int st_rc_open(struct rc_dev *rdev)
206 {
207 struct st_rc_device *dev = rdev->priv;
208 unsigned long flags;
209 local_irq_save(flags);
210 /* enable interrupts and receiver */
211 writel(IRB_RX_INTS, dev->rx_base + IRB_RX_INT_EN);
212 writel(0x01, dev->rx_base + IRB_RX_EN);
213 local_irq_restore(flags);
214
215 return 0;
216 }
217
st_rc_close(struct rc_dev * rdev)218 static void st_rc_close(struct rc_dev *rdev)
219 {
220 struct st_rc_device *dev = rdev->priv;
221 /* disable interrupts and receiver */
222 writel(0x00, dev->rx_base + IRB_RX_EN);
223 writel(0x00, dev->rx_base + IRB_RX_INT_EN);
224 }
225
st_rc_probe(struct platform_device * pdev)226 static int st_rc_probe(struct platform_device *pdev)
227 {
228 int ret = -EINVAL;
229 struct rc_dev *rdev;
230 struct device *dev = &pdev->dev;
231 struct resource *res;
232 struct st_rc_device *rc_dev;
233 struct device_node *np = pdev->dev.of_node;
234 const char *rx_mode;
235
236 rc_dev = devm_kzalloc(dev, sizeof(struct st_rc_device), GFP_KERNEL);
237
238 if (!rc_dev)
239 return -ENOMEM;
240
241 rdev = rc_allocate_device(RC_DRIVER_IR_RAW);
242
243 if (!rdev)
244 return -ENOMEM;
245
246 if (np && !of_property_read_string(np, "rx-mode", &rx_mode)) {
247
248 if (!strcmp(rx_mode, "uhf")) {
249 rc_dev->rxuhfmode = true;
250 } else if (!strcmp(rx_mode, "infrared")) {
251 rc_dev->rxuhfmode = false;
252 } else {
253 dev_err(dev, "Unsupported rx mode [%s]\n", rx_mode);
254 goto err;
255 }
256
257 } else {
258 goto err;
259 }
260
261 rc_dev->sys_clock = devm_clk_get(dev, NULL);
262 if (IS_ERR(rc_dev->sys_clock)) {
263 dev_err(dev, "System clock not found\n");
264 ret = PTR_ERR(rc_dev->sys_clock);
265 goto err;
266 }
267
268 rc_dev->irq = platform_get_irq(pdev, 0);
269 if (rc_dev->irq < 0) {
270 ret = rc_dev->irq;
271 goto err;
272 }
273
274 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
275
276 rc_dev->base = devm_ioremap_resource(dev, res);
277 if (IS_ERR(rc_dev->base)) {
278 ret = PTR_ERR(rc_dev->base);
279 goto err;
280 }
281
282 if (rc_dev->rxuhfmode)
283 rc_dev->rx_base = rc_dev->base + 0x40;
284 else
285 rc_dev->rx_base = rc_dev->base;
286
287 rc_dev->rstc = reset_control_get_optional_exclusive(dev, NULL);
288 if (IS_ERR(rc_dev->rstc)) {
289 ret = PTR_ERR(rc_dev->rstc);
290 goto err;
291 }
292
293 rc_dev->dev = dev;
294 platform_set_drvdata(pdev, rc_dev);
295 st_rc_hardware_init(rc_dev);
296
297 rdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
298 /* rx sampling rate is 10Mhz */
299 rdev->rx_resolution = 100;
300 rdev->timeout = US_TO_NS(MAX_SYMB_TIME);
301 rdev->priv = rc_dev;
302 rdev->open = st_rc_open;
303 rdev->close = st_rc_close;
304 rdev->driver_name = IR_ST_NAME;
305 rdev->map_name = RC_MAP_EMPTY;
306 rdev->device_name = "ST Remote Control Receiver";
307
308 ret = rc_register_device(rdev);
309 if (ret < 0)
310 goto clkerr;
311
312 rc_dev->rdev = rdev;
313 if (devm_request_irq(dev, rc_dev->irq, st_rc_rx_interrupt,
314 0, IR_ST_NAME, rc_dev) < 0) {
315 dev_err(dev, "IRQ %d register failed\n", rc_dev->irq);
316 ret = -EINVAL;
317 goto rcerr;
318 }
319
320 /* enable wake via this device */
321 device_init_wakeup(dev, true);
322 dev_pm_set_wake_irq(dev, rc_dev->irq);
323
324 /*
325 * for LIRC_MODE_MODE2 or LIRC_MODE_PULSE or LIRC_MODE_RAW
326 * lircd expects a long space first before a signal train to sync.
327 */
328 st_rc_send_lirc_timeout(rdev);
329
330 dev_info(dev, "setup in %s mode\n", rc_dev->rxuhfmode ? "UHF" : "IR");
331
332 return ret;
333 rcerr:
334 rc_unregister_device(rdev);
335 rdev = NULL;
336 clkerr:
337 clk_disable_unprepare(rc_dev->sys_clock);
338 err:
339 rc_free_device(rdev);
340 dev_err(dev, "Unable to register device (%d)\n", ret);
341 return ret;
342 }
343
344 #ifdef CONFIG_PM_SLEEP
st_rc_suspend(struct device * dev)345 static int st_rc_suspend(struct device *dev)
346 {
347 struct st_rc_device *rc_dev = dev_get_drvdata(dev);
348
349 if (device_may_wakeup(dev)) {
350 if (!enable_irq_wake(rc_dev->irq))
351 rc_dev->irq_wake = 1;
352 else
353 return -EINVAL;
354 } else {
355 pinctrl_pm_select_sleep_state(dev);
356 writel(0x00, rc_dev->rx_base + IRB_RX_EN);
357 writel(0x00, rc_dev->rx_base + IRB_RX_INT_EN);
358 clk_disable_unprepare(rc_dev->sys_clock);
359 reset_control_assert(rc_dev->rstc);
360 }
361
362 return 0;
363 }
364
st_rc_resume(struct device * dev)365 static int st_rc_resume(struct device *dev)
366 {
367 struct st_rc_device *rc_dev = dev_get_drvdata(dev);
368 struct rc_dev *rdev = rc_dev->rdev;
369
370 if (rc_dev->irq_wake) {
371 disable_irq_wake(rc_dev->irq);
372 rc_dev->irq_wake = 0;
373 } else {
374 pinctrl_pm_select_default_state(dev);
375 st_rc_hardware_init(rc_dev);
376 if (rdev->users) {
377 writel(IRB_RX_INTS, rc_dev->rx_base + IRB_RX_INT_EN);
378 writel(0x01, rc_dev->rx_base + IRB_RX_EN);
379 }
380 }
381
382 return 0;
383 }
384
385 #endif
386
387 static SIMPLE_DEV_PM_OPS(st_rc_pm_ops, st_rc_suspend, st_rc_resume);
388
389 #ifdef CONFIG_OF
390 static const struct of_device_id st_rc_match[] = {
391 { .compatible = "st,comms-irb", },
392 {},
393 };
394
395 MODULE_DEVICE_TABLE(of, st_rc_match);
396 #endif
397
398 static struct platform_driver st_rc_driver = {
399 .driver = {
400 .name = IR_ST_NAME,
401 .of_match_table = of_match_ptr(st_rc_match),
402 .pm = &st_rc_pm_ops,
403 },
404 .probe = st_rc_probe,
405 .remove = st_rc_remove,
406 };
407
408 module_platform_driver(st_rc_driver);
409
410 MODULE_DESCRIPTION("RC Transceiver driver for STMicroelectronics platforms");
411 MODULE_AUTHOR("STMicroelectronics (R&D) Ltd");
412 MODULE_LICENSE("GPL");
413
