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PM / sleep: Asynchronous threads for suspend_noirq
[linux/fpc-iii.git] / drivers / media / rc / st_rc.c
blob8f0cddb9e8f2f4ce0076a9f7a4d4ba0cada0d7b4
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
20 struct st_rc_device {
21 struct device *dev;
22 int irq;
23 int irq_wake;
24 struct clk *sys_clock;
25 void *base; /* Register base address */
26 void *rx_base;/* RX Register base address */
27 struct rc_dev *rdev;
28 bool overclocking;
29 int sample_mult;
30 int sample_div;
31 bool rxuhfmode;
32 struct reset_control *rstc;
33 };
34
35 /* Registers */
36 #define IRB_SAMPLE_RATE_COMM 0x64 /* sample freq divisor*/
37 #define IRB_CLOCK_SEL 0x70 /* clock select */
38 #define IRB_CLOCK_SEL_STATUS 0x74 /* clock status */
39 /* IRB IR/UHF receiver registers */
40 #define IRB_RX_ON 0x40 /* pulse time capture */
41 #define IRB_RX_SYS 0X44 /* sym period capture */
42 #define IRB_RX_INT_EN 0x48 /* IRQ enable (R/W) */
43 #define IRB_RX_INT_STATUS 0x4c /* IRQ status (R/W) */
44 #define IRB_RX_EN 0x50 /* Receive enable */
45 #define IRB_MAX_SYM_PERIOD 0x54 /* max sym value */
46 #define IRB_RX_INT_CLEAR 0x58 /* overrun status */
47 #define IRB_RX_STATUS 0x6c /* receive status */
48 #define IRB_RX_NOISE_SUPPR 0x5c /* noise suppression */
49 #define IRB_RX_POLARITY_INV 0x68 /* polarity inverter */
50
51 /**
52 * IRQ set: Enable full FIFO 1 -> bit 3;
53 * Enable overrun IRQ 1 -> bit 2;
54 * Enable last symbol IRQ 1 -> bit 1:
55 * Enable RX interrupt 1 -> bit 0;
56 */
57 #define IRB_RX_INTS 0x0f
58 #define IRB_RX_OVERRUN_INT 0x04
59 /* maximum symbol period (microsecs),timeout to detect end of symbol train */
60 #define MAX_SYMB_TIME 0x5000
61 #define IRB_SAMPLE_FREQ 10000000
62 #define IRB_FIFO_NOT_EMPTY 0xff00
63 #define IRB_OVERFLOW 0x4
64 #define IRB_TIMEOUT 0xffff
65 #define IR_ST_NAME "st-rc"
66
67 static void st_rc_send_lirc_timeout(struct rc_dev *rdev)
68 {
69 DEFINE_IR_RAW_EVENT(ev);
70 ev.timeout = true;
71 ir_raw_event_store(rdev, &ev);
72 }
73
74 /**
75 * RX graphical example to better understand the difference between ST IR block
76 * output and standard definition used by LIRC (and most of the world!)
77 *
78 * mark mark
79 * |-IRB_RX_ON-| |-IRB_RX_ON-|
80 * ___ ___ ___ ___ ___ ___ _
81 * | | | | | | | | | | | | |
82 * | | | | | | space 0 | | | | | | space 1 |
83 * _____| |__| |__| |____________________________| |__| |__| |_____________|
84 *
85 * |--------------- IRB_RX_SYS -------------|------ IRB_RX_SYS -------|
86 *
87 * |------------- encoding bit 0 -----------|---- encoding bit 1 -----|
88 *
89 * ST hardware returns mark (IRB_RX_ON) and total symbol time (IRB_RX_SYS), so
90 * convert to standard mark/space we have to calculate space=(IRB_RX_SYS-mark)
91 * The mark time represents the amount of time the carrier (usually 36-40kHz)
92 * is detected.The above examples shows Pulse Width Modulation encoding where
93 * bit 0 is represented by space>mark.
94 */
95
96 static irqreturn_t st_rc_rx_interrupt(int irq, void *data)
97 {
98 unsigned int symbol, mark = 0;
99 struct st_rc_device *dev = data;
100 int last_symbol = 0;
101 u32 status;
102 DEFINE_IR_RAW_EVENT(ev);
103
104 if (dev->irq_wake)
105 pm_wakeup_event(dev->dev, 0);
106
107 status = readl(dev->rx_base + IRB_RX_STATUS);
108
109 while (status & (IRB_FIFO_NOT_EMPTY | IRB_OVERFLOW)) {
110 u32 int_status = readl(dev->rx_base + IRB_RX_INT_STATUS);
111 if (unlikely(int_status & IRB_RX_OVERRUN_INT)) {
112 /* discard the entire collection in case of errors! */
113 ir_raw_event_reset(dev->rdev);
114 dev_info(dev->dev, "IR RX overrun\n");
115 writel(IRB_RX_OVERRUN_INT,
116 dev->rx_base + IRB_RX_INT_CLEAR);
117 continue;
118 }
119
120 symbol = readl(dev->rx_base + IRB_RX_SYS);
121 mark = readl(dev->rx_base + IRB_RX_ON);
122
123 if (symbol == IRB_TIMEOUT)
124 last_symbol = 1;
125
126 /* Ignore any noise */
127 if ((mark > 2) && (symbol > 1)) {
128 symbol -= mark;
129 if (dev->overclocking) { /* adjustments to timings */
130 symbol *= dev->sample_mult;
131 symbol /= dev->sample_div;
132 mark *= dev->sample_mult;
133 mark /= dev->sample_div;
134 }
135
136 ev.duration = US_TO_NS(mark);
137 ev.pulse = true;
138 ir_raw_event_store(dev->rdev, &ev);
139
140 if (!last_symbol) {
141 ev.duration = US_TO_NS(symbol);
142 ev.pulse = false;
143 ir_raw_event_store(dev->rdev, &ev);
144 } else {
145 st_rc_send_lirc_timeout(dev->rdev);
146 }
147
148 }
149 last_symbol = 0;
150 status = readl(dev->rx_base + IRB_RX_STATUS);
151 }
152
153 writel(IRB_RX_INTS, dev->rx_base + IRB_RX_INT_CLEAR);
154
155 /* Empty software fifo */
156 ir_raw_event_handle(dev->rdev);
157 return IRQ_HANDLED;
158 }
159
160 static void st_rc_hardware_init(struct st_rc_device *dev)
161 {
162 int baseclock, freqdiff;
163 unsigned int rx_max_symbol_per = MAX_SYMB_TIME;
164 unsigned int rx_sampling_freq_div;
165
166 /* Enable the IP */
167 if (dev->rstc)
168 reset_control_deassert(dev->rstc);
169
170 clk_prepare_enable(dev->sys_clock);
171 baseclock = clk_get_rate(dev->sys_clock);
172
173 /* IRB input pins are inverted internally from high to low. */
174 writel(1, dev->rx_base + IRB_RX_POLARITY_INV);
175
176 rx_sampling_freq_div = baseclock / IRB_SAMPLE_FREQ;
177 writel(rx_sampling_freq_div, dev->base + IRB_SAMPLE_RATE_COMM);
178
179 freqdiff = baseclock - (rx_sampling_freq_div * IRB_SAMPLE_FREQ);
180 if (freqdiff) { /* over clocking, workout the adjustment factors */
181 dev->overclocking = true;
182 dev->sample_mult = 1000;
183 dev->sample_div = baseclock / (10000 * rx_sampling_freq_div);
184 rx_max_symbol_per = (rx_max_symbol_per * 1000)/dev->sample_div;
185 }
186
187 writel(rx_max_symbol_per, dev->rx_base + IRB_MAX_SYM_PERIOD);
188 }
189
190 static int st_rc_remove(struct platform_device *pdev)
191 {
192 struct st_rc_device *rc_dev = platform_get_drvdata(pdev);
193 clk_disable_unprepare(rc_dev->sys_clock);
194 rc_unregister_device(rc_dev->rdev);
195 return 0;
196 }
197
198 static int st_rc_open(struct rc_dev *rdev)
199 {
200 struct st_rc_device *dev = rdev->priv;
201 unsigned long flags;
202 local_irq_save(flags);
203 /* enable interrupts and receiver */
204 writel(IRB_RX_INTS, dev->rx_base + IRB_RX_INT_EN);
205 writel(0x01, dev->rx_base + IRB_RX_EN);
206 local_irq_restore(flags);
207
208 return 0;
209 }
210
211 static void st_rc_close(struct rc_dev *rdev)
212 {
213 struct st_rc_device *dev = rdev->priv;
214 /* disable interrupts and receiver */
215 writel(0x00, dev->rx_base + IRB_RX_EN);
216 writel(0x00, dev->rx_base + IRB_RX_INT_EN);
217 }
218
219 static int st_rc_probe(struct platform_device *pdev)
220 {
221 int ret = -EINVAL;
222 struct rc_dev *rdev;
223 struct device *dev = &pdev->dev;
224 struct resource *res;
225 struct st_rc_device *rc_dev;
226 struct device_node *np = pdev->dev.of_node;
227 const char *rx_mode;
228
229 rc_dev = devm_kzalloc(dev, sizeof(struct st_rc_device), GFP_KERNEL);
230
231 if (!rc_dev)
232 return -ENOMEM;
233
234 rdev = rc_allocate_device();
235
236 if (!rdev)
237 return -ENOMEM;
238
239 if (np && !of_property_read_string(np, "rx-mode", &rx_mode)) {
240
241 if (!strcmp(rx_mode, "uhf")) {
242 rc_dev->rxuhfmode = true;
243 } else if (!strcmp(rx_mode, "infrared")) {
244 rc_dev->rxuhfmode = false;
245 } else {
246 dev_err(dev, "Unsupported rx mode [%s]\n", rx_mode);
247 goto err;
248 }
249
250 } else {
251 goto err;
252 }
253
254 rc_dev->sys_clock = devm_clk_get(dev, NULL);
255 if (IS_ERR(rc_dev->sys_clock)) {
256 dev_err(dev, "System clock not found\n");
257 ret = PTR_ERR(rc_dev->sys_clock);
258 goto err;
259 }
260
261 rc_dev->irq = platform_get_irq(pdev, 0);
262 if (rc_dev->irq < 0) {
263 ret = rc_dev->irq;
264 goto err;
265 }
266
267 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
268
269 rc_dev->base = devm_ioremap_resource(dev, res);
270 if (IS_ERR(rc_dev->base)) {
271 ret = PTR_ERR(rc_dev->base);
272 goto err;
273 }
274
275 if (rc_dev->rxuhfmode)
276 rc_dev->rx_base = rc_dev->base + 0x40;
277 else
278 rc_dev->rx_base = rc_dev->base;
279
280
281 rc_dev->rstc = reset_control_get(dev, NULL);
282 if (IS_ERR(rc_dev->rstc))
283 rc_dev->rstc = NULL;
284
285 rc_dev->dev = dev;
286 platform_set_drvdata(pdev, rc_dev);
287 st_rc_hardware_init(rc_dev);
288
289 rdev->driver_type = RC_DRIVER_IR_RAW;
290 rdev->allowed_protos = RC_BIT_ALL;
291 /* rx sampling rate is 10Mhz */
292 rdev->rx_resolution = 100;
293 rdev->timeout = US_TO_NS(MAX_SYMB_TIME);
294 rdev->priv = rc_dev;
295 rdev->open = st_rc_open;
296 rdev->close = st_rc_close;
297 rdev->driver_name = IR_ST_NAME;
298 rdev->map_name = RC_MAP_LIRC;
299 rdev->input_name = "ST Remote Control Receiver";
300
301 /* enable wake via this device */
302 device_set_wakeup_capable(dev, true);
303 device_set_wakeup_enable(dev, true);
304
305 ret = rc_register_device(rdev);
306 if (ret < 0)
307 goto clkerr;
308
309 rc_dev->rdev = rdev;
310 if (devm_request_irq(dev, rc_dev->irq, st_rc_rx_interrupt,
311 IRQF_NO_SUSPEND, IR_ST_NAME, rc_dev) < 0) {
312 dev_err(dev, "IRQ %d register failed\n", rc_dev->irq);
313 ret = -EINVAL;
314 goto rcerr;
315 }
316
317 /**
318 * for LIRC_MODE_MODE2 or LIRC_MODE_PULSE or LIRC_MODE_RAW
319 * lircd expects a long space first before a signal train to sync.
320 */
321 st_rc_send_lirc_timeout(rdev);
322
323 dev_info(dev, "setup in %s mode\n", rc_dev->rxuhfmode ? "UHF" : "IR");
324
325 return ret;
326 rcerr:
327 rc_unregister_device(rdev);
328 rdev = NULL;
329 clkerr:
330 clk_disable_unprepare(rc_dev->sys_clock);
331 err:
332 rc_free_device(rdev);
333 dev_err(dev, "Unable to register device (%d)\n", ret);
334 return ret;
335 }
336
337 #ifdef CONFIG_PM
338 static int st_rc_suspend(struct device *dev)
339 {
340 struct st_rc_device *rc_dev = dev_get_drvdata(dev);
341
342 if (device_may_wakeup(dev)) {
343 if (!enable_irq_wake(rc_dev->irq))
344 rc_dev->irq_wake = 1;
345 else
346 return -EINVAL;
347 } else {
348 pinctrl_pm_select_sleep_state(dev);
349 writel(0x00, rc_dev->rx_base + IRB_RX_EN);
350 writel(0x00, rc_dev->rx_base + IRB_RX_INT_EN);
351 clk_disable_unprepare(rc_dev->sys_clock);
352 if (rc_dev->rstc)
353 reset_control_assert(rc_dev->rstc);
354 }
355
356 return 0;
357 }
358
359 static int st_rc_resume(struct device *dev)
360 {
361 struct st_rc_device *rc_dev = dev_get_drvdata(dev);
362 struct rc_dev *rdev = rc_dev->rdev;
363
364 if (rc_dev->irq_wake) {
365 disable_irq_wake(rc_dev->irq);
366 rc_dev->irq_wake = 0;
367 } else {
368 pinctrl_pm_select_default_state(dev);
369 st_rc_hardware_init(rc_dev);
370 if (rdev->users) {
371 writel(IRB_RX_INTS, rc_dev->rx_base + IRB_RX_INT_EN);
372 writel(0x01, rc_dev->rx_base + IRB_RX_EN);
373 }
374 }
375
376 return 0;
377 }
378
379 static SIMPLE_DEV_PM_OPS(st_rc_pm_ops, st_rc_suspend, st_rc_resume);
380 #endif
381
382 #ifdef CONFIG_OF
383 static struct of_device_id st_rc_match[] = {
384 { .compatible = "st,comms-irb", },
385 {},
386 };
387
388 MODULE_DEVICE_TABLE(of, st_rc_match);
389 #endif
390
391 static struct platform_driver st_rc_driver = {
392 .driver = {
393 .name = IR_ST_NAME,
394 .owner = THIS_MODULE,
395 .of_match_table = of_match_ptr(st_rc_match),
396 #ifdef CONFIG_PM
397 .pm = &st_rc_pm_ops,
398 #endif
399 },
400 .probe = st_rc_probe,
401 .remove = st_rc_remove,
402 };
403
404 module_platform_driver(st_rc_driver);
405
406 MODULE_DESCRIPTION("RC Transceiver driver for STMicroelectronics platforms");
407 MODULE_AUTHOR("STMicroelectronics (R&D) Ltd");
408 MODULE_LICENSE("GPL");
Linux with added FPC-III support