xref: /openbmc/linux/drivers/media/rc/sunxi-cir.c (revision 6c33a6f4)
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 /* Idle Threshold in samples */
77 #define SUNXI_IR_RXIDLE       20
78 /* Time after which device stops sending data in ms */
79 #define SUNXI_IR_TIMEOUT      120
80 
81 /**
82  * struct sunxi_ir_quirks - Differences between SoC variants.
83  *
84  * @has_reset: SoC needs reset deasserted.
85  * @fifo_size: size of the fifo.
86  */
87 struct sunxi_ir_quirks {
88 	bool		has_reset;
89 	int		fifo_size;
90 };
91 
92 struct sunxi_ir {
93 	spinlock_t      ir_lock;
94 	struct rc_dev   *rc;
95 	void __iomem    *base;
96 	int             irq;
97 	int		fifo_size;
98 	struct clk      *clk;
99 	struct clk      *apb_clk;
100 	struct reset_control *rst;
101 	const char      *map_name;
102 };
103 
104 static irqreturn_t sunxi_ir_irq(int irqno, void *dev_id)
105 {
106 	unsigned long status;
107 	unsigned char dt;
108 	unsigned int cnt, rc;
109 	struct sunxi_ir *ir = dev_id;
110 	struct ir_raw_event rawir = {};
111 
112 	spin_lock(&ir->ir_lock);
113 
114 	status = readl(ir->base + SUNXI_IR_RXSTA_REG);
115 
116 	/* clean all pending statuses */
117 	writel(status | REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
118 
119 	if (status & (REG_RXSTA_RA | REG_RXSTA_RPE)) {
120 		/* How many messages in fifo */
121 		rc  = REG_RXSTA_GET_AC(status);
122 		/* Sanity check */
123 		rc = rc > ir->fifo_size ? ir->fifo_size : rc;
124 		/* If we have data */
125 		for (cnt = 0; cnt < rc; cnt++) {
126 			/* for each bit in fifo */
127 			dt = readb(ir->base + SUNXI_IR_RXFIFO_REG);
128 			rawir.pulse = (dt & 0x80) != 0;
129 			rawir.duration = ((dt & 0x7f) + 1) *
130 					 ir->rc->rx_resolution;
131 			ir_raw_event_store_with_filter(ir->rc, &rawir);
132 		}
133 	}
134 
135 	if (status & REG_RXSTA_ROI) {
136 		ir_raw_event_reset(ir->rc);
137 	} else if (status & REG_RXSTA_RPE) {
138 		ir_raw_event_set_idle(ir->rc, true);
139 		ir_raw_event_handle(ir->rc);
140 	}
141 
142 	spin_unlock(&ir->ir_lock);
143 
144 	return IRQ_HANDLED;
145 }
146 
147 static int sunxi_ir_probe(struct platform_device *pdev)
148 {
149 	int ret = 0;
150 	unsigned long tmp = 0;
151 
152 	struct device *dev = &pdev->dev;
153 	struct device_node *dn = dev->of_node;
154 	const struct sunxi_ir_quirks *quirks;
155 	struct resource *res;
156 	struct sunxi_ir *ir;
157 	u32 b_clk_freq = SUNXI_IR_BASE_CLK;
158 
159 	ir = devm_kzalloc(dev, sizeof(struct sunxi_ir), GFP_KERNEL);
160 	if (!ir)
161 		return -ENOMEM;
162 
163 	quirks = of_device_get_match_data(&pdev->dev);
164 	if (!quirks) {
165 		dev_err(&pdev->dev, "Failed to determine the quirks to use\n");
166 		return -ENODEV;
167 	}
168 
169 	spin_lock_init(&ir->ir_lock);
170 
171 	ir->fifo_size = quirks->fifo_size;
172 
173 	/* Clock */
174 	ir->apb_clk = devm_clk_get(dev, "apb");
175 	if (IS_ERR(ir->apb_clk)) {
176 		dev_err(dev, "failed to get a apb clock.\n");
177 		return PTR_ERR(ir->apb_clk);
178 	}
179 	ir->clk = devm_clk_get(dev, "ir");
180 	if (IS_ERR(ir->clk)) {
181 		dev_err(dev, "failed to get a ir clock.\n");
182 		return PTR_ERR(ir->clk);
183 	}
184 
185 	/* Base clock frequency (optional) */
186 	of_property_read_u32(dn, "clock-frequency", &b_clk_freq);
187 
188 	/* Reset */
189 	if (quirks->has_reset) {
190 		ir->rst = devm_reset_control_get_exclusive(dev, NULL);
191 		if (IS_ERR(ir->rst))
192 			return PTR_ERR(ir->rst);
193 		ret = reset_control_deassert(ir->rst);
194 		if (ret)
195 			return ret;
196 	}
197 
198 	ret = clk_set_rate(ir->clk, b_clk_freq);
199 	if (ret) {
200 		dev_err(dev, "set ir base clock failed!\n");
201 		goto exit_reset_assert;
202 	}
203 	dev_dbg(dev, "set base clock frequency to %d Hz.\n", b_clk_freq);
204 
205 	if (clk_prepare_enable(ir->apb_clk)) {
206 		dev_err(dev, "try to enable apb_ir_clk failed\n");
207 		ret = -EINVAL;
208 		goto exit_reset_assert;
209 	}
210 
211 	if (clk_prepare_enable(ir->clk)) {
212 		dev_err(dev, "try to enable ir_clk failed\n");
213 		ret = -EINVAL;
214 		goto exit_clkdisable_apb_clk;
215 	}
216 
217 	/* IO */
218 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
219 	ir->base = devm_ioremap_resource(dev, res);
220 	if (IS_ERR(ir->base)) {
221 		ret = PTR_ERR(ir->base);
222 		goto exit_clkdisable_clk;
223 	}
224 
225 	ir->rc = rc_allocate_device(RC_DRIVER_IR_RAW);
226 	if (!ir->rc) {
227 		dev_err(dev, "failed to allocate device\n");
228 		ret = -ENOMEM;
229 		goto exit_clkdisable_clk;
230 	}
231 
232 	ir->rc->priv = ir;
233 	ir->rc->device_name = SUNXI_IR_DEV;
234 	ir->rc->input_phys = "sunxi-ir/input0";
235 	ir->rc->input_id.bustype = BUS_HOST;
236 	ir->rc->input_id.vendor = 0x0001;
237 	ir->rc->input_id.product = 0x0001;
238 	ir->rc->input_id.version = 0x0100;
239 	ir->map_name = of_get_property(dn, "linux,rc-map-name", NULL);
240 	ir->rc->map_name = ir->map_name ?: RC_MAP_EMPTY;
241 	ir->rc->dev.parent = dev;
242 	ir->rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
243 	/* Frequency after IR internal divider with sample period in ns */
244 	ir->rc->rx_resolution = (1000000000ul / (b_clk_freq / 64));
245 	ir->rc->timeout = MS_TO_NS(SUNXI_IR_TIMEOUT);
246 	ir->rc->driver_name = SUNXI_IR_DEV;
247 
248 	ret = rc_register_device(ir->rc);
249 	if (ret) {
250 		dev_err(dev, "failed to register rc device\n");
251 		goto exit_free_dev;
252 	}
253 
254 	platform_set_drvdata(pdev, ir);
255 
256 	/* IRQ */
257 	ir->irq = platform_get_irq(pdev, 0);
258 	if (ir->irq < 0) {
259 		ret = ir->irq;
260 		goto exit_free_dev;
261 	}
262 
263 	ret = devm_request_irq(dev, ir->irq, sunxi_ir_irq, 0, SUNXI_IR_DEV, ir);
264 	if (ret) {
265 		dev_err(dev, "failed request irq\n");
266 		goto exit_free_dev;
267 	}
268 
269 	/* Enable CIR Mode */
270 	writel(REG_CTL_MD, ir->base+SUNXI_IR_CTL_REG);
271 
272 	/* Set noise threshold and idle threshold */
273 	writel(REG_CIR_NTHR(SUNXI_IR_RXNOISE)|REG_CIR_ITHR(SUNXI_IR_RXIDLE),
274 	       ir->base + SUNXI_IR_CIR_REG);
275 
276 	/* Invert Input Signal */
277 	writel(REG_RXCTL_RPPI, ir->base + SUNXI_IR_RXCTL_REG);
278 
279 	/* Clear All Rx Interrupt Status */
280 	writel(REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
281 
282 	/*
283 	 * Enable IRQ on overflow, packet end, FIFO available with trigger
284 	 * level
285 	 */
286 	writel(REG_RXINT_ROI_EN | REG_RXINT_RPEI_EN |
287 	       REG_RXINT_RAI_EN | REG_RXINT_RAL(ir->fifo_size / 2 - 1),
288 	       ir->base + SUNXI_IR_RXINT_REG);
289 
290 	/* Enable IR Module */
291 	tmp = readl(ir->base + SUNXI_IR_CTL_REG);
292 	writel(tmp | REG_CTL_GEN | REG_CTL_RXEN, ir->base + SUNXI_IR_CTL_REG);
293 
294 	dev_info(dev, "initialized sunXi IR driver\n");
295 	return 0;
296 
297 exit_free_dev:
298 	rc_free_device(ir->rc);
299 exit_clkdisable_clk:
300 	clk_disable_unprepare(ir->clk);
301 exit_clkdisable_apb_clk:
302 	clk_disable_unprepare(ir->apb_clk);
303 exit_reset_assert:
304 	reset_control_assert(ir->rst);
305 
306 	return ret;
307 }
308 
309 static int sunxi_ir_remove(struct platform_device *pdev)
310 {
311 	unsigned long flags;
312 	struct sunxi_ir *ir = platform_get_drvdata(pdev);
313 
314 	clk_disable_unprepare(ir->clk);
315 	clk_disable_unprepare(ir->apb_clk);
316 	reset_control_assert(ir->rst);
317 
318 	spin_lock_irqsave(&ir->ir_lock, flags);
319 	/* disable IR IRQ */
320 	writel(0, ir->base + SUNXI_IR_RXINT_REG);
321 	/* clear All Rx Interrupt Status */
322 	writel(REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
323 	/* disable IR */
324 	writel(0, ir->base + SUNXI_IR_CTL_REG);
325 	spin_unlock_irqrestore(&ir->ir_lock, flags);
326 
327 	rc_unregister_device(ir->rc);
328 	return 0;
329 }
330 
331 static const struct sunxi_ir_quirks sun4i_a10_ir_quirks = {
332 	.has_reset = false,
333 	.fifo_size = 16,
334 };
335 
336 static const struct sunxi_ir_quirks sun5i_a13_ir_quirks = {
337 	.has_reset = false,
338 	.fifo_size = 64,
339 };
340 
341 static const struct sunxi_ir_quirks sun6i_a31_ir_quirks = {
342 	.has_reset = true,
343 	.fifo_size = 64,
344 };
345 
346 static const struct of_device_id sunxi_ir_match[] = {
347 	{
348 		.compatible = "allwinner,sun4i-a10-ir",
349 		.data = &sun4i_a10_ir_quirks,
350 	},
351 	{
352 		.compatible = "allwinner,sun5i-a13-ir",
353 		.data = &sun5i_a13_ir_quirks,
354 	},
355 	{
356 		.compatible = "allwinner,sun6i-a31-ir",
357 		.data = &sun6i_a31_ir_quirks,
358 	},
359 	{}
360 };
361 MODULE_DEVICE_TABLE(of, sunxi_ir_match);
362 
363 static struct platform_driver sunxi_ir_driver = {
364 	.probe          = sunxi_ir_probe,
365 	.remove         = sunxi_ir_remove,
366 	.driver = {
367 		.name = SUNXI_IR_DEV,
368 		.of_match_table = sunxi_ir_match,
369 	},
370 };
371 
372 module_platform_driver(sunxi_ir_driver);
373 
374 MODULE_DESCRIPTION("Allwinner sunXi IR controller driver");
375 MODULE_AUTHOR("Alexsey Shestacov <wingrime@linux-sunxi.org>");
376 MODULE_LICENSE("GPL");
377