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treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / drivers / media / rc / st_rc.c
blob1dc4e2e337054e1f3128227ec1844e836c75b52f
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2013 STMicroelectronics Limited
4 * Author: Srinivas Kandagatla <srinivas.kandagatla@st.com>
5 */
6 #include <linux/kernel.h>
7 #include <linux/clk.h>
8 #include <linux/interrupt.h>
9 #include <linux/module.h>
10 #include <linux/of.h>
11 #include <linux/platform_device.h>
12 #include <linux/reset.h>
13 #include <media/rc-core.h>
14 #include <linux/pinctrl/consumer.h>
15 #include <linux/pm_wakeirq.h>
16
17 struct st_rc_device {
18 struct device *dev;
19 int irq;
20 int irq_wake;
21 struct clk *sys_clock;
22 void __iomem *base; /* Register base address */
23 void __iomem *rx_base;/* RX Register base address */
24 struct rc_dev *rdev;
25 bool overclocking;
26 int sample_mult;
27 int sample_div;
28 bool rxuhfmode;
29 struct reset_control *rstc;
30 };
31
32 /* Registers */
33 #define IRB_SAMPLE_RATE_COMM 0x64 /* sample freq divisor*/
34 #define IRB_CLOCK_SEL 0x70 /* clock select */
35 #define IRB_CLOCK_SEL_STATUS 0x74 /* clock status */
36 /* IRB IR/UHF receiver registers */
37 #define IRB_RX_ON 0x40 /* pulse time capture */
38 #define IRB_RX_SYS 0X44 /* sym period capture */
39 #define IRB_RX_INT_EN 0x48 /* IRQ enable (R/W) */
40 #define IRB_RX_INT_STATUS 0x4c /* IRQ status (R/W) */
41 #define IRB_RX_EN 0x50 /* Receive enable */
42 #define IRB_MAX_SYM_PERIOD 0x54 /* max sym value */
43 #define IRB_RX_INT_CLEAR 0x58 /* overrun status */
44 #define IRB_RX_STATUS 0x6c /* receive status */
45 #define IRB_RX_NOISE_SUPPR 0x5c /* noise suppression */
46 #define IRB_RX_POLARITY_INV 0x68 /* polarity inverter */
47
48 /*
49 * IRQ set: Enable full FIFO 1 -> bit 3;
50 * Enable overrun IRQ 1 -> bit 2;
51 * Enable last symbol IRQ 1 -> bit 1:
52 * Enable RX interrupt 1 -> bit 0;
53 */
54 #define IRB_RX_INTS 0x0f
55 #define IRB_RX_OVERRUN_INT 0x04
56 /* maximum symbol period (microsecs),timeout to detect end of symbol train */
57 #define MAX_SYMB_TIME 0x5000
58 #define IRB_SAMPLE_FREQ 10000000
59 #define IRB_FIFO_NOT_EMPTY 0xff00
60 #define IRB_OVERFLOW 0x4
61 #define IRB_TIMEOUT 0xffff
62 #define IR_ST_NAME "st-rc"
63
64 static void st_rc_send_lirc_timeout(struct rc_dev *rdev)
65 {
66 struct ir_raw_event ev = { .timeout = true, .duration = rdev->timeout };
67 ir_raw_event_store(rdev, &ev);
68 }
69
70 /*
71 * RX graphical example to better understand the difference between ST IR block
72 * output and standard definition used by LIRC (and most of the world!)
73 *
74 * mark mark
75 * |-IRB_RX_ON-| |-IRB_RX_ON-|
76 * ___ ___ ___ ___ ___ ___ _
77 * | | | | | | | | | | | | |
78 * | | | | | | space 0 | | | | | | space 1 |
79 * _____| |__| |__| |____________________________| |__| |__| |_____________|
80 *
81 * |--------------- IRB_RX_SYS -------------|------ IRB_RX_SYS -------|
82 *
83 * |------------- encoding bit 0 -----------|---- encoding bit 1 -----|
84 *
85 * ST hardware returns mark (IRB_RX_ON) and total symbol time (IRB_RX_SYS), so
86 * convert to standard mark/space we have to calculate space=(IRB_RX_SYS-mark)
87 * The mark time represents the amount of time the carrier (usually 36-40kHz)
88 * is detected.The above examples shows Pulse Width Modulation encoding where
89 * bit 0 is represented by space>mark.
90 */
91
92 static irqreturn_t st_rc_rx_interrupt(int irq, void *data)
93 {
94 unsigned long timeout;
95 unsigned int symbol, mark = 0;
96 struct st_rc_device *dev = data;
97 int last_symbol = 0;
98 u32 status, int_status;
99 struct ir_raw_event ev = {};
100
101 if (dev->irq_wake)
102 pm_wakeup_event(dev->dev, 0);
103
104 /* FIXME: is 10ms good enough ? */
105 timeout = jiffies + msecs_to_jiffies(10);
106 do {
107 status = readl(dev->rx_base + IRB_RX_STATUS);
108 if (!(status & (IRB_FIFO_NOT_EMPTY | IRB_OVERFLOW)))
109 break;
110
111 int_status = readl(dev->rx_base + IRB_RX_INT_STATUS);
112 if (unlikely(int_status & IRB_RX_OVERRUN_INT)) {
113 /* discard the entire collection in case of errors! */
114 ir_raw_event_reset(dev->rdev);
115 dev_info(dev->dev, "IR RX overrun\n");
116 writel(IRB_RX_OVERRUN_INT,
117 dev->rx_base + IRB_RX_INT_CLEAR);
118 continue;
119 }
120
121 symbol = readl(dev->rx_base + IRB_RX_SYS);
122 mark = readl(dev->rx_base + IRB_RX_ON);
123
124 if (symbol == IRB_TIMEOUT)
125 last_symbol = 1;
126
127 /* Ignore any noise */
128 if ((mark > 2) && (symbol > 1)) {
129 symbol -= mark;
130 if (dev->overclocking) { /* adjustments to timings */
131 symbol *= dev->sample_mult;
132 symbol /= dev->sample_div;
133 mark *= dev->sample_mult;
134 mark /= dev->sample_div;
135 }
136
137 ev.duration = US_TO_NS(mark);
138 ev.pulse = true;
139 ir_raw_event_store(dev->rdev, &ev);
140
141 if (!last_symbol) {
142 ev.duration = US_TO_NS(symbol);
143 ev.pulse = false;
144 ir_raw_event_store(dev->rdev, &ev);
145 } else {
146 st_rc_send_lirc_timeout(dev->rdev);
147 }
148
149 }
150 last_symbol = 0;
151 } while (time_is_after_jiffies(timeout));
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 reset_control_deassert(dev->rstc);
168
169 clk_prepare_enable(dev->sys_clock);
170 baseclock = clk_get_rate(dev->sys_clock);
171
172 /* IRB input pins are inverted internally from high to low. */
173 writel(1, dev->rx_base + IRB_RX_POLARITY_INV);
174
175 rx_sampling_freq_div = baseclock / IRB_SAMPLE_FREQ;
176 writel(rx_sampling_freq_div, dev->base + IRB_SAMPLE_RATE_COMM);
177
178 freqdiff = baseclock - (rx_sampling_freq_div * IRB_SAMPLE_FREQ);
179 if (freqdiff) { /* over clocking, workout the adjustment factors */
180 dev->overclocking = true;
181 dev->sample_mult = 1000;
182 dev->sample_div = baseclock / (10000 * rx_sampling_freq_div);
183 rx_max_symbol_per = (rx_max_symbol_per * 1000)/dev->sample_div;
184 }
185
186 writel(rx_max_symbol_per, dev->rx_base + IRB_MAX_SYM_PERIOD);
187 }
188
189 static int st_rc_remove(struct platform_device *pdev)
190 {
191 struct st_rc_device *rc_dev = platform_get_drvdata(pdev);
192
193 dev_pm_clear_wake_irq(&pdev->dev);
194 device_init_wakeup(&pdev->dev, false);
195 clk_disable_unprepare(rc_dev->sys_clock);
196 rc_unregister_device(rc_dev->rdev);
197 return 0;
198 }
199
200 static int st_rc_open(struct rc_dev *rdev)
201 {
202 struct st_rc_device *dev = rdev->priv;
203 unsigned long flags;
204 local_irq_save(flags);
205 /* enable interrupts and receiver */
206 writel(IRB_RX_INTS, dev->rx_base + IRB_RX_INT_EN);
207 writel(0x01, dev->rx_base + IRB_RX_EN);
208 local_irq_restore(flags);
209
210 return 0;
211 }
212
213 static void st_rc_close(struct rc_dev *rdev)
214 {
215 struct st_rc_device *dev = rdev->priv;
216 /* disable interrupts and receiver */
217 writel(0x00, dev->rx_base + IRB_RX_EN);
218 writel(0x00, dev->rx_base + IRB_RX_INT_EN);
219 }
220
221 static int st_rc_probe(struct platform_device *pdev)
222 {
223 int ret = -EINVAL;
224 struct rc_dev *rdev;
225 struct device *dev = &pdev->dev;
226 struct resource *res;
227 struct st_rc_device *rc_dev;
228 struct device_node *np = pdev->dev.of_node;
229 const char *rx_mode;
230
231 rc_dev = devm_kzalloc(dev, sizeof(struct st_rc_device), GFP_KERNEL);
232
233 if (!rc_dev)
234 return -ENOMEM;
235
236 rdev = rc_allocate_device(RC_DRIVER_IR_RAW);
237
238 if (!rdev)
239 return -ENOMEM;
240
241 if (np && !of_property_read_string(np, "rx-mode", &rx_mode)) {
242
243 if (!strcmp(rx_mode, "uhf")) {
244 rc_dev->rxuhfmode = true;
245 } else if (!strcmp(rx_mode, "infrared")) {
246 rc_dev->rxuhfmode = false;
247 } else {
248 dev_err(dev, "Unsupported rx mode [%s]\n", rx_mode);
249 goto err;
250 }
251
252 } else {
253 goto err;
254 }
255
256 rc_dev->sys_clock = devm_clk_get(dev, NULL);
257 if (IS_ERR(rc_dev->sys_clock)) {
258 dev_err(dev, "System clock not found\n");
259 ret = PTR_ERR(rc_dev->sys_clock);
260 goto err;
261 }
262
263 rc_dev->irq = platform_get_irq(pdev, 0);
264 if (rc_dev->irq < 0) {
265 ret = rc_dev->irq;
266 goto err;
267 }
268
269 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
270
271 rc_dev->base = devm_ioremap_resource(dev, res);
272 if (IS_ERR(rc_dev->base)) {
273 ret = PTR_ERR(rc_dev->base);
274 goto err;
275 }
276
277 if (rc_dev->rxuhfmode)
278 rc_dev->rx_base = rc_dev->base + 0x40;
279 else
280 rc_dev->rx_base = rc_dev->base;
281
282 rc_dev->rstc = reset_control_get_optional_exclusive(dev, NULL);
283 if (IS_ERR(rc_dev->rstc)) {
284 ret = PTR_ERR(rc_dev->rstc);
285 goto err;
286 }
287
288 rc_dev->dev = dev;
289 platform_set_drvdata(pdev, rc_dev);
290 st_rc_hardware_init(rc_dev);
291
292 rdev->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
293 /* rx sampling rate is 10Mhz */
294 rdev->rx_resolution = 100;
295 rdev->timeout = US_TO_NS(MAX_SYMB_TIME);
296 rdev->priv = rc_dev;
297 rdev->open = st_rc_open;
298 rdev->close = st_rc_close;
299 rdev->driver_name = IR_ST_NAME;
300 rdev->map_name = RC_MAP_EMPTY;
301 rdev->device_name = "ST Remote Control Receiver";
302
303 ret = rc_register_device(rdev);
304 if (ret < 0)
305 goto clkerr;
306
307 rc_dev->rdev = rdev;
308 if (devm_request_irq(dev, rc_dev->irq, st_rc_rx_interrupt,
309 0, IR_ST_NAME, rc_dev) < 0) {
310 dev_err(dev, "IRQ %d register failed\n", rc_dev->irq);
311 ret = -EINVAL;
312 goto rcerr;
313 }
314
315 /* enable wake via this device */
316 device_init_wakeup(dev, true);
317 dev_pm_set_wake_irq(dev, rc_dev->irq);
318
319 /*
320 * for LIRC_MODE_MODE2 or LIRC_MODE_PULSE or LIRC_MODE_RAW
321 * lircd expects a long space first before a signal train to sync.
322 */
323 st_rc_send_lirc_timeout(rdev);
324
325 dev_info(dev, "setup in %s mode\n", rc_dev->rxuhfmode ? "UHF" : "IR");
326
327 return ret;
328 rcerr:
329 rc_unregister_device(rdev);
330 rdev = NULL;
331 clkerr:
332 clk_disable_unprepare(rc_dev->sys_clock);
333 err:
334 rc_free_device(rdev);
335 dev_err(dev, "Unable to register device (%d)\n", ret);
336 return ret;
337 }
338
339 #ifdef CONFIG_PM_SLEEP
340 static int st_rc_suspend(struct device *dev)
341 {
342 struct st_rc_device *rc_dev = dev_get_drvdata(dev);
343
344 if (device_may_wakeup(dev)) {
345 if (!enable_irq_wake(rc_dev->irq))
346 rc_dev->irq_wake = 1;
347 else
348 return -EINVAL;
349 } else {
350 pinctrl_pm_select_sleep_state(dev);
351 writel(0x00, rc_dev->rx_base + IRB_RX_EN);
352 writel(0x00, rc_dev->rx_base + IRB_RX_INT_EN);
353 clk_disable_unprepare(rc_dev->sys_clock);
354 reset_control_assert(rc_dev->rstc);
355 }
356
357 return 0;
358 }
359
360 static int st_rc_resume(struct device *dev)
361 {
362 struct st_rc_device *rc_dev = dev_get_drvdata(dev);
363 struct rc_dev *rdev = rc_dev->rdev;
364
365 if (rc_dev->irq_wake) {
366 disable_irq_wake(rc_dev->irq);
367 rc_dev->irq_wake = 0;
368 } else {
369 pinctrl_pm_select_default_state(dev);
370 st_rc_hardware_init(rc_dev);
371 if (rdev->users) {
372 writel(IRB_RX_INTS, rc_dev->rx_base + IRB_RX_INT_EN);
373 writel(0x01, rc_dev->rx_base + IRB_RX_EN);
374 }
375 }
376
377 return 0;
378 }
379
380 #endif
381
382 static SIMPLE_DEV_PM_OPS(st_rc_pm_ops, st_rc_suspend, st_rc_resume);
383
384 #ifdef CONFIG_OF
385 static const struct of_device_id st_rc_match[] = {
386 { .compatible = "st,comms-irb", },
387 {},
388 };
389
390 MODULE_DEVICE_TABLE(of, st_rc_match);
391 #endif
392
393 static struct platform_driver st_rc_driver = {
394 .driver = {
395 .name = IR_ST_NAME,
396 .of_match_table = of_match_ptr(st_rc_match),
397 .pm = &st_rc_pm_ops,
398 },
399 .probe = st_rc_probe,
400 .remove = st_rc_remove,
401 };
402
403 module_platform_driver(st_rc_driver);
404
405 MODULE_DESCRIPTION("RC Transceiver driver for STMicroelectronics platforms");
406 MODULE_AUTHOR("STMicroelectronics (R&D) Ltd");
407 MODULE_LICENSE("GPL");
Linux with added FPC-III support