xref: /linux/drivers/media/rc/sunxi-cir.c (revision 3f41368fbfe1b3d5922d317fe1a0a0cab6846802)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Driver for Allwinner sunXi IR controller
4  *
5  * Copyright (C) 2014 Alexsey Shestacov <wingrime@linux-sunxi.org>
6  * Copyright (C) 2014 Alexander Bersenev <bay@hackerdom.ru>
7  *
8  * Based on sun5i-ir.c:
9  * Copyright (C) 2007-2012 Daniel Wang
10  * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
11  */
12 
13 #include <linux/clk.h>
14 #include <linux/interrupt.h>
15 #include <linux/io.h>
16 #include <linux/module.h>
17 #include <linux/of.h>
18 #include <linux/platform_device.h>
19 #include <linux/reset.h>
20 #include <media/rc-core.h>
21 
22 #define SUNXI_IR_DEV "sunxi-ir"
23 
24 /* Registers */
25 /* IR Control */
26 #define SUNXI_IR_CTL_REG      0x00
27 /* Global Enable */
28 #define REG_CTL_GEN			BIT(0)
29 /* RX block enable */
30 #define REG_CTL_RXEN			BIT(1)
31 /* CIR mode */
32 #define REG_CTL_MD			(BIT(4) | BIT(5))
33 
34 /* Rx Config */
35 #define SUNXI_IR_RXCTL_REG    0x10
36 /* Pulse Polarity Invert flag */
37 #define REG_RXCTL_RPPI			BIT(2)
38 
39 /* Rx Data */
40 #define SUNXI_IR_RXFIFO_REG   0x20
41 
42 /* Rx Interrupt Enable */
43 #define SUNXI_IR_RXINT_REG    0x2C
44 /* Rx FIFO Overflow Interrupt Enable */
45 #define REG_RXINT_ROI_EN		BIT(0)
46 /* Rx Packet End Interrupt Enable */
47 #define REG_RXINT_RPEI_EN		BIT(1)
48 /* Rx FIFO Data Available Interrupt Enable */
49 #define REG_RXINT_RAI_EN		BIT(4)
50 
51 /* Rx FIFO available byte level */
52 #define REG_RXINT_RAL(val)    ((val) << 8)
53 
54 /* Rx Interrupt Status */
55 #define SUNXI_IR_RXSTA_REG    0x30
56 /* Rx FIFO Overflow */
57 #define REG_RXSTA_ROI			REG_RXINT_ROI_EN
58 /* Rx Packet End */
59 #define REG_RXSTA_RPE			REG_RXINT_RPEI_EN
60 /* Rx FIFO Data Available */
61 #define REG_RXSTA_RA			REG_RXINT_RAI_EN
62 /* RX FIFO Get Available Counter */
63 #define REG_RXSTA_GET_AC(val) (((val) >> 8) & (ir->fifo_size * 2 - 1))
64 /* Clear all interrupt status value */
65 #define REG_RXSTA_CLEARALL    0xff
66 
67 /* IR Sample Config */
68 #define SUNXI_IR_CIR_REG      0x34
69 /* CIR_REG register noise threshold */
70 #define REG_CIR_NTHR(val)    (((val) << 2) & (GENMASK(7, 2)))
71 /* CIR_REG register idle threshold */
72 #define REG_CIR_ITHR(val)    (((val) << 8) & (GENMASK(15, 8)))
73 
74 /* Required frequency for IR0 or IR1 clock in CIR mode (default) */
75 #define SUNXI_IR_BASE_CLK     8000000
76 /* Noise threshold in samples  */
77 #define SUNXI_IR_RXNOISE      1
78 
79 /**
80  * struct sunxi_ir_quirks - Differences between SoC variants.
81  *
82  * @has_reset: SoC needs reset deasserted.
83  * @fifo_size: size of the fifo.
84  */
85 struct sunxi_ir_quirks {
86 	bool		has_reset;
87 	int		fifo_size;
88 };
89 
90 struct sunxi_ir {
91 	struct rc_dev   *rc;
92 	void __iomem    *base;
93 	int             irq;
94 	int		fifo_size;
95 	struct clk      *clk;
96 	struct clk      *apb_clk;
97 	struct reset_control *rst;
98 	const char      *map_name;
99 };
100 
101 static irqreturn_t sunxi_ir_irq(int irqno, void *dev_id)
102 {
103 	unsigned long status;
104 	unsigned char dt;
105 	unsigned int cnt, rc;
106 	struct sunxi_ir *ir = dev_id;
107 	struct ir_raw_event rawir = {};
108 
109 	status = readl(ir->base + SUNXI_IR_RXSTA_REG);
110 
111 	/* clean all pending statuses */
112 	writel(status | REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
113 
114 	if (status & (REG_RXSTA_RA | REG_RXSTA_RPE)) {
115 		/* How many messages in fifo */
116 		rc  = REG_RXSTA_GET_AC(status);
117 		/* Sanity check */
118 		rc = rc > ir->fifo_size ? ir->fifo_size : rc;
119 		/* If we have data */
120 		for (cnt = 0; cnt < rc; cnt++) {
121 			/* for each bit in fifo */
122 			dt = readb(ir->base + SUNXI_IR_RXFIFO_REG);
123 			rawir.pulse = (dt & 0x80) != 0;
124 			rawir.duration = ((dt & 0x7f) + 1) *
125 					 ir->rc->rx_resolution;
126 			ir_raw_event_store_with_filter(ir->rc, &rawir);
127 		}
128 	}
129 
130 	if (status & REG_RXSTA_ROI) {
131 		ir_raw_event_overflow(ir->rc);
132 	} else if (status & REG_RXSTA_RPE) {
133 		ir_raw_event_set_idle(ir->rc, true);
134 		ir_raw_event_handle(ir->rc);
135 	} else {
136 		ir_raw_event_handle(ir->rc);
137 	}
138 
139 	return IRQ_HANDLED;
140 }
141 
142 /* Convert idle threshold to usec */
143 static unsigned int sunxi_ithr_to_usec(unsigned int base_clk, unsigned int ithr)
144 {
145 	return DIV_ROUND_CLOSEST(USEC_PER_SEC * (ithr + 1),
146 				 base_clk / (128 * 64));
147 }
148 
149 /* Convert usec to idle threshold */
150 static unsigned int sunxi_usec_to_ithr(unsigned int base_clk, unsigned int usec)
151 {
152 	/* make sure we don't end up with a timeout less than requested */
153 	return DIV_ROUND_UP((base_clk / (128 * 64)) * usec,  USEC_PER_SEC) - 1;
154 }
155 
156 static int sunxi_ir_set_timeout(struct rc_dev *rc_dev, unsigned int timeout)
157 {
158 	struct sunxi_ir *ir = rc_dev->priv;
159 	unsigned int base_clk = clk_get_rate(ir->clk);
160 
161 	unsigned int ithr = sunxi_usec_to_ithr(base_clk, timeout);
162 
163 	dev_dbg(rc_dev->dev.parent, "setting idle threshold to %u\n", ithr);
164 
165 	/* Set noise threshold and idle threshold */
166 	writel(REG_CIR_NTHR(SUNXI_IR_RXNOISE) | REG_CIR_ITHR(ithr),
167 	       ir->base + SUNXI_IR_CIR_REG);
168 
169 	rc_dev->timeout = sunxi_ithr_to_usec(base_clk, ithr);
170 
171 	return 0;
172 }
173 
174 static int sunxi_ir_hw_init(struct device *dev)
175 {
176 	struct sunxi_ir *ir = dev_get_drvdata(dev);
177 	u32 tmp;
178 	int ret;
179 
180 	ret = reset_control_deassert(ir->rst);
181 	if (ret)
182 		return ret;
183 
184 	ret = clk_prepare_enable(ir->apb_clk);
185 	if (ret) {
186 		dev_err(dev, "failed to enable apb clk\n");
187 		goto exit_assert_reset;
188 	}
189 
190 	ret = clk_prepare_enable(ir->clk);
191 	if (ret) {
192 		dev_err(dev, "failed to enable ir clk\n");
193 		goto exit_disable_apb_clk;
194 	}
195 
196 	/* Enable CIR Mode */
197 	writel(REG_CTL_MD, ir->base + SUNXI_IR_CTL_REG);
198 
199 	/* Set noise threshold and idle threshold */
200 	sunxi_ir_set_timeout(ir->rc, ir->rc->timeout);
201 
202 	/* Invert Input Signal */
203 	writel(REG_RXCTL_RPPI, ir->base + SUNXI_IR_RXCTL_REG);
204 
205 	/* Clear All Rx Interrupt Status */
206 	writel(REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
207 
208 	/*
209 	 * Enable IRQ on overflow, packet end, FIFO available with trigger
210 	 * level
211 	 */
212 	writel(REG_RXINT_ROI_EN | REG_RXINT_RPEI_EN |
213 	       REG_RXINT_RAI_EN | REG_RXINT_RAL(ir->fifo_size / 2 - 1),
214 	       ir->base + SUNXI_IR_RXINT_REG);
215 
216 	/* Enable IR Module */
217 	tmp = readl(ir->base + SUNXI_IR_CTL_REG);
218 	writel(tmp | REG_CTL_GEN | REG_CTL_RXEN, ir->base + SUNXI_IR_CTL_REG);
219 
220 	return 0;
221 
222 exit_disable_apb_clk:
223 	clk_disable_unprepare(ir->apb_clk);
224 exit_assert_reset:
225 	reset_control_assert(ir->rst);
226 
227 	return ret;
228 }
229 
230 static void sunxi_ir_hw_exit(struct device *dev)
231 {
232 	struct sunxi_ir *ir = dev_get_drvdata(dev);
233 
234 	clk_disable_unprepare(ir->clk);
235 	clk_disable_unprepare(ir->apb_clk);
236 	reset_control_assert(ir->rst);
237 }
238 
239 static int __maybe_unused sunxi_ir_suspend(struct device *dev)
240 {
241 	sunxi_ir_hw_exit(dev);
242 
243 	return 0;
244 }
245 
246 static int __maybe_unused sunxi_ir_resume(struct device *dev)
247 {
248 	return sunxi_ir_hw_init(dev);
249 }
250 
251 static SIMPLE_DEV_PM_OPS(sunxi_ir_pm_ops, sunxi_ir_suspend, sunxi_ir_resume);
252 
253 static int sunxi_ir_probe(struct platform_device *pdev)
254 {
255 	int ret = 0;
256 
257 	struct device *dev = &pdev->dev;
258 	struct device_node *dn = dev->of_node;
259 	const struct sunxi_ir_quirks *quirks;
260 	struct sunxi_ir *ir;
261 	u32 b_clk_freq = SUNXI_IR_BASE_CLK;
262 
263 	ir = devm_kzalloc(dev, sizeof(struct sunxi_ir), GFP_KERNEL);
264 	if (!ir)
265 		return -ENOMEM;
266 
267 	quirks = of_device_get_match_data(&pdev->dev);
268 	if (!quirks) {
269 		dev_err(&pdev->dev, "Failed to determine the quirks to use\n");
270 		return -ENODEV;
271 	}
272 
273 	ir->fifo_size = quirks->fifo_size;
274 
275 	/* Clock */
276 	ir->apb_clk = devm_clk_get(dev, "apb");
277 	if (IS_ERR(ir->apb_clk)) {
278 		dev_err(dev, "failed to get a apb clock.\n");
279 		return PTR_ERR(ir->apb_clk);
280 	}
281 	ir->clk = devm_clk_get(dev, "ir");
282 	if (IS_ERR(ir->clk)) {
283 		dev_err(dev, "failed to get a ir clock.\n");
284 		return PTR_ERR(ir->clk);
285 	}
286 
287 	/* Base clock frequency (optional) */
288 	of_property_read_u32(dn, "clock-frequency", &b_clk_freq);
289 
290 	/* Reset */
291 	if (quirks->has_reset) {
292 		ir->rst = devm_reset_control_get_exclusive(dev, NULL);
293 		if (IS_ERR(ir->rst))
294 			return PTR_ERR(ir->rst);
295 	}
296 
297 	ret = clk_set_rate(ir->clk, b_clk_freq);
298 	if (ret) {
299 		dev_err(dev, "set ir base clock failed!\n");
300 		return ret;
301 	}
302 	dev_dbg(dev, "set base clock frequency to %d Hz.\n", b_clk_freq);
303 
304 	/* IO */
305 	ir->base = devm_platform_ioremap_resource(pdev, 0);
306 	if (IS_ERR(ir->base)) {
307 		return PTR_ERR(ir->base);
308 	}
309 
310 	ir->rc = rc_allocate_device(RC_DRIVER_IR_RAW);
311 	if (!ir->rc) {
312 		dev_err(dev, "failed to allocate device\n");
313 		return -ENOMEM;
314 	}
315 
316 	ir->rc->priv = ir;
317 	ir->rc->device_name = SUNXI_IR_DEV;
318 	ir->rc->input_phys = "sunxi-ir/input0";
319 	ir->rc->input_id.bustype = BUS_HOST;
320 	ir->rc->input_id.vendor = 0x0001;
321 	ir->rc->input_id.product = 0x0001;
322 	ir->rc->input_id.version = 0x0100;
323 	ir->map_name = of_get_property(dn, "linux,rc-map-name", NULL);
324 	ir->rc->map_name = ir->map_name ?: RC_MAP_EMPTY;
325 	ir->rc->dev.parent = dev;
326 	ir->rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
327 	/* Frequency after IR internal divider with sample period in us */
328 	ir->rc->rx_resolution = (USEC_PER_SEC / (b_clk_freq / 64));
329 	ir->rc->timeout = IR_DEFAULT_TIMEOUT;
330 	ir->rc->min_timeout = sunxi_ithr_to_usec(b_clk_freq, 0);
331 	ir->rc->max_timeout = sunxi_ithr_to_usec(b_clk_freq, 255);
332 	ir->rc->s_timeout = sunxi_ir_set_timeout;
333 	ir->rc->driver_name = SUNXI_IR_DEV;
334 
335 	ret = rc_register_device(ir->rc);
336 	if (ret) {
337 		dev_err(dev, "failed to register rc device\n");
338 		goto exit_free_dev;
339 	}
340 
341 	platform_set_drvdata(pdev, ir);
342 
343 	/* IRQ */
344 	ir->irq = platform_get_irq(pdev, 0);
345 	if (ir->irq < 0) {
346 		ret = ir->irq;
347 		goto exit_free_dev;
348 	}
349 
350 	ret = devm_request_irq(dev, ir->irq, sunxi_ir_irq, 0, SUNXI_IR_DEV, ir);
351 	if (ret) {
352 		dev_err(dev, "failed request irq\n");
353 		goto exit_free_dev;
354 	}
355 
356 	ret = sunxi_ir_hw_init(dev);
357 	if (ret)
358 		goto exit_free_dev;
359 
360 	dev_info(dev, "initialized sunXi IR driver\n");
361 	return 0;
362 
363 exit_free_dev:
364 	rc_free_device(ir->rc);
365 
366 	return ret;
367 }
368 
369 static void sunxi_ir_remove(struct platform_device *pdev)
370 {
371 	struct sunxi_ir *ir = platform_get_drvdata(pdev);
372 
373 	rc_unregister_device(ir->rc);
374 	sunxi_ir_hw_exit(&pdev->dev);
375 }
376 
377 static void sunxi_ir_shutdown(struct platform_device *pdev)
378 {
379 	sunxi_ir_hw_exit(&pdev->dev);
380 }
381 
382 static const struct sunxi_ir_quirks sun4i_a10_ir_quirks = {
383 	.has_reset = false,
384 	.fifo_size = 16,
385 };
386 
387 static const struct sunxi_ir_quirks sun5i_a13_ir_quirks = {
388 	.has_reset = false,
389 	.fifo_size = 64,
390 };
391 
392 static const struct sunxi_ir_quirks sun6i_a31_ir_quirks = {
393 	.has_reset = true,
394 	.fifo_size = 64,
395 };
396 
397 static const struct of_device_id sunxi_ir_match[] = {
398 	{
399 		.compatible = "allwinner,sun4i-a10-ir",
400 		.data = &sun4i_a10_ir_quirks,
401 	},
402 	{
403 		.compatible = "allwinner,sun5i-a13-ir",
404 		.data = &sun5i_a13_ir_quirks,
405 	},
406 	{
407 		.compatible = "allwinner,sun6i-a31-ir",
408 		.data = &sun6i_a31_ir_quirks,
409 	},
410 	{}
411 };
412 MODULE_DEVICE_TABLE(of, sunxi_ir_match);
413 
414 static struct platform_driver sunxi_ir_driver = {
415 	.probe          = sunxi_ir_probe,
416 	.remove_new     = sunxi_ir_remove,
417 	.shutdown       = sunxi_ir_shutdown,
418 	.driver = {
419 		.name = SUNXI_IR_DEV,
420 		.of_match_table = sunxi_ir_match,
421 		.pm = &sunxi_ir_pm_ops,
422 	},
423 };
424 
425 module_platform_driver(sunxi_ir_driver);
426 
427 MODULE_DESCRIPTION("Allwinner sunXi IR controller driver");
428 MODULE_AUTHOR("Alexsey Shestacov <wingrime@linux-sunxi.org>");
429 MODULE_LICENSE("GPL");
430