xref: /openbmc/linux/drivers/media/rc/sunxi-cir.c (revision 703e7713)
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/module.h>
16 #include <linux/of_platform.h>
17 #include <linux/reset.h>
18 #include <media/rc-core.h>
19 
20 #define SUNXI_IR_DEV "sunxi-ir"
21 
22 /* Registers */
23 /* IR Control */
24 #define SUNXI_IR_CTL_REG      0x00
25 /* Global Enable */
26 #define REG_CTL_GEN			BIT(0)
27 /* RX block enable */
28 #define REG_CTL_RXEN			BIT(1)
29 /* CIR mode */
30 #define REG_CTL_MD			(BIT(4) | BIT(5))
31 
32 /* Rx Config */
33 #define SUNXI_IR_RXCTL_REG    0x10
34 /* Pulse Polarity Invert flag */
35 #define REG_RXCTL_RPPI			BIT(2)
36 
37 /* Rx Data */
38 #define SUNXI_IR_RXFIFO_REG   0x20
39 
40 /* Rx Interrupt Enable */
41 #define SUNXI_IR_RXINT_REG    0x2C
42 /* Rx FIFO Overflow Interrupt Enable */
43 #define REG_RXINT_ROI_EN		BIT(0)
44 /* Rx Packet End Interrupt Enable */
45 #define REG_RXINT_RPEI_EN		BIT(1)
46 /* Rx FIFO Data Available Interrupt Enable */
47 #define REG_RXINT_RAI_EN		BIT(4)
48 
49 /* Rx FIFO available byte level */
50 #define REG_RXINT_RAL(val)    ((val) << 8)
51 
52 /* Rx Interrupt Status */
53 #define SUNXI_IR_RXSTA_REG    0x30
54 /* Rx FIFO Overflow */
55 #define REG_RXSTA_ROI			REG_RXINT_ROI_EN
56 /* Rx Packet End */
57 #define REG_RXSTA_RPE			REG_RXINT_RPEI_EN
58 /* Rx FIFO Data Available */
59 #define REG_RXSTA_RA			REG_RXINT_RAI_EN
60 /* RX FIFO Get Available Counter */
61 #define REG_RXSTA_GET_AC(val) (((val) >> 8) & (ir->fifo_size * 2 - 1))
62 /* Clear all interrupt status value */
63 #define REG_RXSTA_CLEARALL    0xff
64 
65 /* IR Sample Config */
66 #define SUNXI_IR_CIR_REG      0x34
67 /* CIR_REG register noise threshold */
68 #define REG_CIR_NTHR(val)    (((val) << 2) & (GENMASK(7, 2)))
69 /* CIR_REG register idle threshold */
70 #define REG_CIR_ITHR(val)    (((val) << 8) & (GENMASK(15, 8)))
71 
72 /* Required frequency for IR0 or IR1 clock in CIR mode (default) */
73 #define SUNXI_IR_BASE_CLK     8000000
74 /* Noise threshold in samples  */
75 #define SUNXI_IR_RXNOISE      1
76 
77 /**
78  * struct sunxi_ir_quirks - Differences between SoC variants.
79  *
80  * @has_reset: SoC needs reset deasserted.
81  * @fifo_size: size of the fifo.
82  */
83 struct sunxi_ir_quirks {
84 	bool		has_reset;
85 	int		fifo_size;
86 };
87 
88 struct sunxi_ir {
89 	struct rc_dev   *rc;
90 	void __iomem    *base;
91 	int             irq;
92 	int		fifo_size;
93 	struct clk      *clk;
94 	struct clk      *apb_clk;
95 	struct reset_control *rst;
96 	const char      *map_name;
97 };
98 
99 static irqreturn_t sunxi_ir_irq(int irqno, void *dev_id)
100 {
101 	unsigned long status;
102 	unsigned char dt;
103 	unsigned int cnt, rc;
104 	struct sunxi_ir *ir = dev_id;
105 	struct ir_raw_event rawir = {};
106 
107 	status = readl(ir->base + SUNXI_IR_RXSTA_REG);
108 
109 	/* clean all pending statuses */
110 	writel(status | REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
111 
112 	if (status & (REG_RXSTA_RA | REG_RXSTA_RPE)) {
113 		/* How many messages in fifo */
114 		rc  = REG_RXSTA_GET_AC(status);
115 		/* Sanity check */
116 		rc = rc > ir->fifo_size ? ir->fifo_size : rc;
117 		/* If we have data */
118 		for (cnt = 0; cnt < rc; cnt++) {
119 			/* for each bit in fifo */
120 			dt = readb(ir->base + SUNXI_IR_RXFIFO_REG);
121 			rawir.pulse = (dt & 0x80) != 0;
122 			rawir.duration = ((dt & 0x7f) + 1) *
123 					 ir->rc->rx_resolution;
124 			ir_raw_event_store_with_filter(ir->rc, &rawir);
125 		}
126 	}
127 
128 	if (status & REG_RXSTA_ROI) {
129 		ir_raw_event_overflow(ir->rc);
130 	} else if (status & REG_RXSTA_RPE) {
131 		ir_raw_event_set_idle(ir->rc, true);
132 		ir_raw_event_handle(ir->rc);
133 	} else {
134 		ir_raw_event_handle(ir->rc);
135 	}
136 
137 	return IRQ_HANDLED;
138 }
139 
140 /* Convert idle threshold to usec */
141 static unsigned int sunxi_ithr_to_usec(unsigned int base_clk, unsigned int ithr)
142 {
143 	return DIV_ROUND_CLOSEST(USEC_PER_SEC * (ithr + 1),
144 				 base_clk / (128 * 64));
145 }
146 
147 /* Convert usec to idle threshold */
148 static unsigned int sunxi_usec_to_ithr(unsigned int base_clk, unsigned int usec)
149 {
150 	/* make sure we don't end up with a timeout less than requested */
151 	return DIV_ROUND_UP((base_clk / (128 * 64)) * usec,  USEC_PER_SEC) - 1;
152 }
153 
154 static int sunxi_ir_set_timeout(struct rc_dev *rc_dev, unsigned int timeout)
155 {
156 	struct sunxi_ir *ir = rc_dev->priv;
157 	unsigned int base_clk = clk_get_rate(ir->clk);
158 
159 	unsigned int ithr = sunxi_usec_to_ithr(base_clk, timeout);
160 
161 	dev_dbg(rc_dev->dev.parent, "setting idle threshold to %u\n", ithr);
162 
163 	/* Set noise threshold and idle threshold */
164 	writel(REG_CIR_NTHR(SUNXI_IR_RXNOISE) | REG_CIR_ITHR(ithr),
165 	       ir->base + SUNXI_IR_CIR_REG);
166 
167 	rc_dev->timeout = sunxi_ithr_to_usec(base_clk, ithr);
168 
169 	return 0;
170 }
171 
172 static int sunxi_ir_hw_init(struct device *dev)
173 {
174 	struct sunxi_ir *ir = dev_get_drvdata(dev);
175 	u32 tmp;
176 	int ret;
177 
178 	ret = reset_control_deassert(ir->rst);
179 	if (ret)
180 		return ret;
181 
182 	ret = clk_prepare_enable(ir->apb_clk);
183 	if (ret) {
184 		dev_err(dev, "failed to enable apb clk\n");
185 		goto exit_assert_reset;
186 	}
187 
188 	ret = clk_prepare_enable(ir->clk);
189 	if (ret) {
190 		dev_err(dev, "failed to enable ir clk\n");
191 		goto exit_disable_apb_clk;
192 	}
193 
194 	/* Enable CIR Mode */
195 	writel(REG_CTL_MD, ir->base + SUNXI_IR_CTL_REG);
196 
197 	/* Set noise threshold and idle threshold */
198 	sunxi_ir_set_timeout(ir->rc, ir->rc->timeout);
199 
200 	/* Invert Input Signal */
201 	writel(REG_RXCTL_RPPI, ir->base + SUNXI_IR_RXCTL_REG);
202 
203 	/* Clear All Rx Interrupt Status */
204 	writel(REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
205 
206 	/*
207 	 * Enable IRQ on overflow, packet end, FIFO available with trigger
208 	 * level
209 	 */
210 	writel(REG_RXINT_ROI_EN | REG_RXINT_RPEI_EN |
211 	       REG_RXINT_RAI_EN | REG_RXINT_RAL(ir->fifo_size / 2 - 1),
212 	       ir->base + SUNXI_IR_RXINT_REG);
213 
214 	/* Enable IR Module */
215 	tmp = readl(ir->base + SUNXI_IR_CTL_REG);
216 	writel(tmp | REG_CTL_GEN | REG_CTL_RXEN, ir->base + SUNXI_IR_CTL_REG);
217 
218 	return 0;
219 
220 exit_disable_apb_clk:
221 	clk_disable_unprepare(ir->apb_clk);
222 exit_assert_reset:
223 	reset_control_assert(ir->rst);
224 
225 	return ret;
226 }
227 
228 static void sunxi_ir_hw_exit(struct device *dev)
229 {
230 	struct sunxi_ir *ir = dev_get_drvdata(dev);
231 
232 	clk_disable_unprepare(ir->clk);
233 	clk_disable_unprepare(ir->apb_clk);
234 	reset_control_assert(ir->rst);
235 }
236 
237 static int __maybe_unused sunxi_ir_suspend(struct device *dev)
238 {
239 	sunxi_ir_hw_exit(dev);
240 
241 	return 0;
242 }
243 
244 static int __maybe_unused sunxi_ir_resume(struct device *dev)
245 {
246 	return sunxi_ir_hw_init(dev);
247 }
248 
249 static SIMPLE_DEV_PM_OPS(sunxi_ir_pm_ops, sunxi_ir_suspend, sunxi_ir_resume);
250 
251 static int sunxi_ir_probe(struct platform_device *pdev)
252 {
253 	int ret = 0;
254 
255 	struct device *dev = &pdev->dev;
256 	struct device_node *dn = dev->of_node;
257 	const struct sunxi_ir_quirks *quirks;
258 	struct sunxi_ir *ir;
259 	u32 b_clk_freq = SUNXI_IR_BASE_CLK;
260 
261 	ir = devm_kzalloc(dev, sizeof(struct sunxi_ir), GFP_KERNEL);
262 	if (!ir)
263 		return -ENOMEM;
264 
265 	quirks = of_device_get_match_data(&pdev->dev);
266 	if (!quirks) {
267 		dev_err(&pdev->dev, "Failed to determine the quirks to use\n");
268 		return -ENODEV;
269 	}
270 
271 	ir->fifo_size = quirks->fifo_size;
272 
273 	/* Clock */
274 	ir->apb_clk = devm_clk_get(dev, "apb");
275 	if (IS_ERR(ir->apb_clk)) {
276 		dev_err(dev, "failed to get a apb clock.\n");
277 		return PTR_ERR(ir->apb_clk);
278 	}
279 	ir->clk = devm_clk_get(dev, "ir");
280 	if (IS_ERR(ir->clk)) {
281 		dev_err(dev, "failed to get a ir clock.\n");
282 		return PTR_ERR(ir->clk);
283 	}
284 
285 	/* Base clock frequency (optional) */
286 	of_property_read_u32(dn, "clock-frequency", &b_clk_freq);
287 
288 	/* Reset */
289 	if (quirks->has_reset) {
290 		ir->rst = devm_reset_control_get_exclusive(dev, NULL);
291 		if (IS_ERR(ir->rst))
292 			return PTR_ERR(ir->rst);
293 	}
294 
295 	ret = clk_set_rate(ir->clk, b_clk_freq);
296 	if (ret) {
297 		dev_err(dev, "set ir base clock failed!\n");
298 		return ret;
299 	}
300 	dev_dbg(dev, "set base clock frequency to %d Hz.\n", b_clk_freq);
301 
302 	/* IO */
303 	ir->base = devm_platform_ioremap_resource(pdev, 0);
304 	if (IS_ERR(ir->base)) {
305 		return PTR_ERR(ir->base);
306 	}
307 
308 	ir->rc = rc_allocate_device(RC_DRIVER_IR_RAW);
309 	if (!ir->rc) {
310 		dev_err(dev, "failed to allocate device\n");
311 		return -ENOMEM;
312 	}
313 
314 	ir->rc->priv = ir;
315 	ir->rc->device_name = SUNXI_IR_DEV;
316 	ir->rc->input_phys = "sunxi-ir/input0";
317 	ir->rc->input_id.bustype = BUS_HOST;
318 	ir->rc->input_id.vendor = 0x0001;
319 	ir->rc->input_id.product = 0x0001;
320 	ir->rc->input_id.version = 0x0100;
321 	ir->map_name = of_get_property(dn, "linux,rc-map-name", NULL);
322 	ir->rc->map_name = ir->map_name ?: RC_MAP_EMPTY;
323 	ir->rc->dev.parent = dev;
324 	ir->rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
325 	/* Frequency after IR internal divider with sample period in us */
326 	ir->rc->rx_resolution = (USEC_PER_SEC / (b_clk_freq / 64));
327 	ir->rc->timeout = IR_DEFAULT_TIMEOUT;
328 	ir->rc->min_timeout = sunxi_ithr_to_usec(b_clk_freq, 0);
329 	ir->rc->max_timeout = sunxi_ithr_to_usec(b_clk_freq, 255);
330 	ir->rc->s_timeout = sunxi_ir_set_timeout;
331 	ir->rc->driver_name = SUNXI_IR_DEV;
332 
333 	ret = rc_register_device(ir->rc);
334 	if (ret) {
335 		dev_err(dev, "failed to register rc device\n");
336 		goto exit_free_dev;
337 	}
338 
339 	platform_set_drvdata(pdev, ir);
340 
341 	/* IRQ */
342 	ir->irq = platform_get_irq(pdev, 0);
343 	if (ir->irq < 0) {
344 		ret = ir->irq;
345 		goto exit_free_dev;
346 	}
347 
348 	ret = devm_request_irq(dev, ir->irq, sunxi_ir_irq, 0, SUNXI_IR_DEV, ir);
349 	if (ret) {
350 		dev_err(dev, "failed request irq\n");
351 		goto exit_free_dev;
352 	}
353 
354 	ret = sunxi_ir_hw_init(dev);
355 	if (ret)
356 		goto exit_free_dev;
357 
358 	dev_info(dev, "initialized sunXi IR driver\n");
359 	return 0;
360 
361 exit_free_dev:
362 	rc_free_device(ir->rc);
363 
364 	return ret;
365 }
366 
367 static void sunxi_ir_remove(struct platform_device *pdev)
368 {
369 	struct sunxi_ir *ir = platform_get_drvdata(pdev);
370 
371 	rc_unregister_device(ir->rc);
372 	sunxi_ir_hw_exit(&pdev->dev);
373 }
374 
375 static void sunxi_ir_shutdown(struct platform_device *pdev)
376 {
377 	sunxi_ir_hw_exit(&pdev->dev);
378 }
379 
380 static const struct sunxi_ir_quirks sun4i_a10_ir_quirks = {
381 	.has_reset = false,
382 	.fifo_size = 16,
383 };
384 
385 static const struct sunxi_ir_quirks sun5i_a13_ir_quirks = {
386 	.has_reset = false,
387 	.fifo_size = 64,
388 };
389 
390 static const struct sunxi_ir_quirks sun6i_a31_ir_quirks = {
391 	.has_reset = true,
392 	.fifo_size = 64,
393 };
394 
395 static const struct of_device_id sunxi_ir_match[] = {
396 	{
397 		.compatible = "allwinner,sun4i-a10-ir",
398 		.data = &sun4i_a10_ir_quirks,
399 	},
400 	{
401 		.compatible = "allwinner,sun5i-a13-ir",
402 		.data = &sun5i_a13_ir_quirks,
403 	},
404 	{
405 		.compatible = "allwinner,sun6i-a31-ir",
406 		.data = &sun6i_a31_ir_quirks,
407 	},
408 	{}
409 };
410 MODULE_DEVICE_TABLE(of, sunxi_ir_match);
411 
412 static struct platform_driver sunxi_ir_driver = {
413 	.probe          = sunxi_ir_probe,
414 	.remove_new     = sunxi_ir_remove,
415 	.shutdown       = sunxi_ir_shutdown,
416 	.driver = {
417 		.name = SUNXI_IR_DEV,
418 		.of_match_table = sunxi_ir_match,
419 		.pm = &sunxi_ir_pm_ops,
420 	},
421 };
422 
423 module_platform_driver(sunxi_ir_driver);
424 
425 MODULE_DESCRIPTION("Allwinner sunXi IR controller driver");
426 MODULE_AUTHOR("Alexsey Shestacov <wingrime@linux-sunxi.org>");
427 MODULE_LICENSE("GPL");
428