xref: /openbmc/linux/drivers/media/rc/sunxi-cir.c (revision 84b102f5)
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 	spinlock_t      ir_lock;
90 	struct rc_dev   *rc;
91 	void __iomem    *base;
92 	int             irq;
93 	int		fifo_size;
94 	struct clk      *clk;
95 	struct clk      *apb_clk;
96 	struct reset_control *rst;
97 	const char      *map_name;
98 };
99 
100 static irqreturn_t sunxi_ir_irq(int irqno, void *dev_id)
101 {
102 	unsigned long status;
103 	unsigned char dt;
104 	unsigned int cnt, rc;
105 	struct sunxi_ir *ir = dev_id;
106 	struct ir_raw_event rawir = {};
107 
108 	spin_lock(&ir->ir_lock);
109 
110 	status = readl(ir->base + SUNXI_IR_RXSTA_REG);
111 
112 	/* clean all pending statuses */
113 	writel(status | REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
114 
115 	if (status & (REG_RXSTA_RA | REG_RXSTA_RPE)) {
116 		/* How many messages in fifo */
117 		rc  = REG_RXSTA_GET_AC(status);
118 		/* Sanity check */
119 		rc = rc > ir->fifo_size ? ir->fifo_size : rc;
120 		/* If we have data */
121 		for (cnt = 0; cnt < rc; cnt++) {
122 			/* for each bit in fifo */
123 			dt = readb(ir->base + SUNXI_IR_RXFIFO_REG);
124 			rawir.pulse = (dt & 0x80) != 0;
125 			rawir.duration = ((dt & 0x7f) + 1) *
126 					 ir->rc->rx_resolution;
127 			ir_raw_event_store_with_filter(ir->rc, &rawir);
128 		}
129 	}
130 
131 	if (status & REG_RXSTA_ROI) {
132 		ir_raw_event_reset(ir->rc);
133 	} else if (status & REG_RXSTA_RPE) {
134 		ir_raw_event_set_idle(ir->rc, true);
135 		ir_raw_event_handle(ir->rc);
136 	} else {
137 		ir_raw_event_handle(ir->rc);
138 	}
139 
140 	spin_unlock(&ir->ir_lock);
141 
142 	return IRQ_HANDLED;
143 }
144 
145 /* Convert idle threshold to usec */
146 static unsigned int sunxi_ithr_to_usec(unsigned int base_clk, unsigned int ithr)
147 {
148 	return DIV_ROUND_CLOSEST(USEC_PER_SEC * (ithr + 1),
149 				 base_clk / (128 * 64));
150 }
151 
152 /* Convert usec to idle threshold */
153 static unsigned int sunxi_usec_to_ithr(unsigned int base_clk, unsigned int usec)
154 {
155 	/* make sure we don't end up with a timeout less than requested */
156 	return DIV_ROUND_UP((base_clk / (128 * 64)) * usec,  USEC_PER_SEC) - 1;
157 }
158 
159 static int sunxi_ir_set_timeout(struct rc_dev *rc_dev, unsigned int timeout)
160 {
161 	struct sunxi_ir *ir = rc_dev->priv;
162 	unsigned int base_clk = clk_get_rate(ir->clk);
163 	unsigned long flags;
164 
165 	unsigned int ithr = sunxi_usec_to_ithr(base_clk, timeout);
166 
167 	dev_dbg(rc_dev->dev.parent, "setting idle threshold to %u\n", ithr);
168 
169 	spin_lock_irqsave(&ir->ir_lock, flags);
170 	/* Set noise threshold and idle threshold */
171 	writel(REG_CIR_NTHR(SUNXI_IR_RXNOISE) | REG_CIR_ITHR(ithr),
172 	       ir->base + SUNXI_IR_CIR_REG);
173 	spin_unlock_irqrestore(&ir->ir_lock, flags);
174 
175 	rc_dev->timeout = sunxi_ithr_to_usec(base_clk, ithr);
176 
177 	return 0;
178 }
179 
180 static int sunxi_ir_probe(struct platform_device *pdev)
181 {
182 	int ret = 0;
183 	unsigned long tmp = 0;
184 
185 	struct device *dev = &pdev->dev;
186 	struct device_node *dn = dev->of_node;
187 	const struct sunxi_ir_quirks *quirks;
188 	struct resource *res;
189 	struct sunxi_ir *ir;
190 	u32 b_clk_freq = SUNXI_IR_BASE_CLK;
191 
192 	ir = devm_kzalloc(dev, sizeof(struct sunxi_ir), GFP_KERNEL);
193 	if (!ir)
194 		return -ENOMEM;
195 
196 	quirks = of_device_get_match_data(&pdev->dev);
197 	if (!quirks) {
198 		dev_err(&pdev->dev, "Failed to determine the quirks to use\n");
199 		return -ENODEV;
200 	}
201 
202 	spin_lock_init(&ir->ir_lock);
203 
204 	ir->fifo_size = quirks->fifo_size;
205 
206 	/* Clock */
207 	ir->apb_clk = devm_clk_get(dev, "apb");
208 	if (IS_ERR(ir->apb_clk)) {
209 		dev_err(dev, "failed to get a apb clock.\n");
210 		return PTR_ERR(ir->apb_clk);
211 	}
212 	ir->clk = devm_clk_get(dev, "ir");
213 	if (IS_ERR(ir->clk)) {
214 		dev_err(dev, "failed to get a ir clock.\n");
215 		return PTR_ERR(ir->clk);
216 	}
217 
218 	/* Base clock frequency (optional) */
219 	of_property_read_u32(dn, "clock-frequency", &b_clk_freq);
220 
221 	/* Reset */
222 	if (quirks->has_reset) {
223 		ir->rst = devm_reset_control_get_exclusive(dev, NULL);
224 		if (IS_ERR(ir->rst))
225 			return PTR_ERR(ir->rst);
226 		ret = reset_control_deassert(ir->rst);
227 		if (ret)
228 			return ret;
229 	}
230 
231 	ret = clk_set_rate(ir->clk, b_clk_freq);
232 	if (ret) {
233 		dev_err(dev, "set ir base clock failed!\n");
234 		goto exit_reset_assert;
235 	}
236 	dev_dbg(dev, "set base clock frequency to %d Hz.\n", b_clk_freq);
237 
238 	if (clk_prepare_enable(ir->apb_clk)) {
239 		dev_err(dev, "try to enable apb_ir_clk failed\n");
240 		ret = -EINVAL;
241 		goto exit_reset_assert;
242 	}
243 
244 	if (clk_prepare_enable(ir->clk)) {
245 		dev_err(dev, "try to enable ir_clk failed\n");
246 		ret = -EINVAL;
247 		goto exit_clkdisable_apb_clk;
248 	}
249 
250 	/* IO */
251 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
252 	ir->base = devm_ioremap_resource(dev, res);
253 	if (IS_ERR(ir->base)) {
254 		ret = PTR_ERR(ir->base);
255 		goto exit_clkdisable_clk;
256 	}
257 
258 	ir->rc = rc_allocate_device(RC_DRIVER_IR_RAW);
259 	if (!ir->rc) {
260 		dev_err(dev, "failed to allocate device\n");
261 		ret = -ENOMEM;
262 		goto exit_clkdisable_clk;
263 	}
264 
265 	ir->rc->priv = ir;
266 	ir->rc->device_name = SUNXI_IR_DEV;
267 	ir->rc->input_phys = "sunxi-ir/input0";
268 	ir->rc->input_id.bustype = BUS_HOST;
269 	ir->rc->input_id.vendor = 0x0001;
270 	ir->rc->input_id.product = 0x0001;
271 	ir->rc->input_id.version = 0x0100;
272 	ir->map_name = of_get_property(dn, "linux,rc-map-name", NULL);
273 	ir->rc->map_name = ir->map_name ?: RC_MAP_EMPTY;
274 	ir->rc->dev.parent = dev;
275 	ir->rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
276 	/* Frequency after IR internal divider with sample period in us */
277 	ir->rc->rx_resolution = (USEC_PER_SEC / (b_clk_freq / 64));
278 	ir->rc->min_timeout = sunxi_ithr_to_usec(b_clk_freq, 0);
279 	ir->rc->max_timeout = sunxi_ithr_to_usec(b_clk_freq, 255);
280 	ir->rc->s_timeout = sunxi_ir_set_timeout;
281 	ir->rc->driver_name = SUNXI_IR_DEV;
282 
283 	ret = rc_register_device(ir->rc);
284 	if (ret) {
285 		dev_err(dev, "failed to register rc device\n");
286 		goto exit_free_dev;
287 	}
288 
289 	platform_set_drvdata(pdev, ir);
290 
291 	/* IRQ */
292 	ir->irq = platform_get_irq(pdev, 0);
293 	if (ir->irq < 0) {
294 		ret = ir->irq;
295 		goto exit_free_dev;
296 	}
297 
298 	ret = devm_request_irq(dev, ir->irq, sunxi_ir_irq, 0, SUNXI_IR_DEV, ir);
299 	if (ret) {
300 		dev_err(dev, "failed request irq\n");
301 		goto exit_free_dev;
302 	}
303 
304 	/* Enable CIR Mode */
305 	writel(REG_CTL_MD, ir->base+SUNXI_IR_CTL_REG);
306 
307 	/* Set noise threshold and idle threshold */
308 	sunxi_ir_set_timeout(ir->rc, IR_DEFAULT_TIMEOUT);
309 
310 	/* Invert Input Signal */
311 	writel(REG_RXCTL_RPPI, ir->base + SUNXI_IR_RXCTL_REG);
312 
313 	/* Clear All Rx Interrupt Status */
314 	writel(REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
315 
316 	/*
317 	 * Enable IRQ on overflow, packet end, FIFO available with trigger
318 	 * level
319 	 */
320 	writel(REG_RXINT_ROI_EN | REG_RXINT_RPEI_EN |
321 	       REG_RXINT_RAI_EN | REG_RXINT_RAL(ir->fifo_size / 2 - 1),
322 	       ir->base + SUNXI_IR_RXINT_REG);
323 
324 	/* Enable IR Module */
325 	tmp = readl(ir->base + SUNXI_IR_CTL_REG);
326 	writel(tmp | REG_CTL_GEN | REG_CTL_RXEN, ir->base + SUNXI_IR_CTL_REG);
327 
328 	dev_info(dev, "initialized sunXi IR driver\n");
329 	return 0;
330 
331 exit_free_dev:
332 	rc_free_device(ir->rc);
333 exit_clkdisable_clk:
334 	clk_disable_unprepare(ir->clk);
335 exit_clkdisable_apb_clk:
336 	clk_disable_unprepare(ir->apb_clk);
337 exit_reset_assert:
338 	reset_control_assert(ir->rst);
339 
340 	return ret;
341 }
342 
343 static int sunxi_ir_remove(struct platform_device *pdev)
344 {
345 	unsigned long flags;
346 	struct sunxi_ir *ir = platform_get_drvdata(pdev);
347 
348 	clk_disable_unprepare(ir->clk);
349 	clk_disable_unprepare(ir->apb_clk);
350 	reset_control_assert(ir->rst);
351 
352 	spin_lock_irqsave(&ir->ir_lock, flags);
353 	/* disable IR IRQ */
354 	writel(0, ir->base + SUNXI_IR_RXINT_REG);
355 	/* clear All Rx Interrupt Status */
356 	writel(REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
357 	/* disable IR */
358 	writel(0, ir->base + SUNXI_IR_CTL_REG);
359 	spin_unlock_irqrestore(&ir->ir_lock, flags);
360 
361 	rc_unregister_device(ir->rc);
362 	return 0;
363 }
364 
365 static const struct sunxi_ir_quirks sun4i_a10_ir_quirks = {
366 	.has_reset = false,
367 	.fifo_size = 16,
368 };
369 
370 static const struct sunxi_ir_quirks sun5i_a13_ir_quirks = {
371 	.has_reset = false,
372 	.fifo_size = 64,
373 };
374 
375 static const struct sunxi_ir_quirks sun6i_a31_ir_quirks = {
376 	.has_reset = true,
377 	.fifo_size = 64,
378 };
379 
380 static const struct of_device_id sunxi_ir_match[] = {
381 	{
382 		.compatible = "allwinner,sun4i-a10-ir",
383 		.data = &sun4i_a10_ir_quirks,
384 	},
385 	{
386 		.compatible = "allwinner,sun5i-a13-ir",
387 		.data = &sun5i_a13_ir_quirks,
388 	},
389 	{
390 		.compatible = "allwinner,sun6i-a31-ir",
391 		.data = &sun6i_a31_ir_quirks,
392 	},
393 	{}
394 };
395 MODULE_DEVICE_TABLE(of, sunxi_ir_match);
396 
397 static struct platform_driver sunxi_ir_driver = {
398 	.probe          = sunxi_ir_probe,
399 	.remove         = sunxi_ir_remove,
400 	.driver = {
401 		.name = SUNXI_IR_DEV,
402 		.of_match_table = sunxi_ir_match,
403 	},
404 };
405 
406 module_platform_driver(sunxi_ir_driver);
407 
408 MODULE_DESCRIPTION("Allwinner sunXi IR controller driver");
409 MODULE_AUTHOR("Alexsey Shestacov <wingrime@linux-sunxi.org>");
410 MODULE_LICENSE("GPL");
411