xref: /openbmc/linux/drivers/media/rc/sunxi-cir.c (revision aac5987a)
1 /*
2  * Driver for Allwinner sunXi IR controller
3  *
4  * Copyright (C) 2014 Alexsey Shestacov <wingrime@linux-sunxi.org>
5  * Copyright (C) 2014 Alexander Bersenev <bay@hackerdom.ru>
6  *
7  * Based on sun5i-ir.c:
8  * Copyright (C) 2007-2012 Daniel Wang
9  * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
10  *
11  * This program is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU General Public License as
13  * published by the Free Software Foundation; either version 2 of
14  * the License, or (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19  * GNU General Public License for more details.
20  */
21 
22 #include <linux/clk.h>
23 #include <linux/interrupt.h>
24 #include <linux/module.h>
25 #include <linux/of_platform.h>
26 #include <linux/reset.h>
27 #include <media/rc-core.h>
28 
29 #define SUNXI_IR_DEV "sunxi-ir"
30 
31 /* Registers */
32 /* IR Control */
33 #define SUNXI_IR_CTL_REG      0x00
34 /* Global Enable */
35 #define REG_CTL_GEN			BIT(0)
36 /* RX block enable */
37 #define REG_CTL_RXEN			BIT(1)
38 /* CIR mode */
39 #define REG_CTL_MD			(BIT(4) | BIT(5))
40 
41 /* Rx Config */
42 #define SUNXI_IR_RXCTL_REG    0x10
43 /* Pulse Polarity Invert flag */
44 #define REG_RXCTL_RPPI			BIT(2)
45 
46 /* Rx Data */
47 #define SUNXI_IR_RXFIFO_REG   0x20
48 
49 /* Rx Interrupt Enable */
50 #define SUNXI_IR_RXINT_REG    0x2C
51 /* Rx FIFO Overflow */
52 #define REG_RXINT_ROI_EN		BIT(0)
53 /* Rx Packet End */
54 #define REG_RXINT_RPEI_EN		BIT(1)
55 /* Rx FIFO Data Available */
56 #define REG_RXINT_RAI_EN		BIT(4)
57 
58 /* Rx FIFO available byte level */
59 #define REG_RXINT_RAL(val)    ((val) << 8)
60 
61 /* Rx Interrupt Status */
62 #define SUNXI_IR_RXSTA_REG    0x30
63 /* RX FIFO Get Available Counter */
64 #define REG_RXSTA_GET_AC(val) (((val) >> 8) & (ir->fifo_size * 2 - 1))
65 /* Clear all interrupt status value */
66 #define REG_RXSTA_CLEARALL    0xff
67 
68 /* IR Sample Config */
69 #define SUNXI_IR_CIR_REG      0x34
70 /* CIR_REG register noise threshold */
71 #define REG_CIR_NTHR(val)    (((val) << 2) & (GENMASK(7, 2)))
72 /* CIR_REG register idle threshold */
73 #define REG_CIR_ITHR(val)    (((val) << 8) & (GENMASK(15, 8)))
74 
75 /* Required frequency for IR0 or IR1 clock in CIR mode */
76 #define SUNXI_IR_BASE_CLK     8000000
77 /* Frequency after IR internal divider  */
78 #define SUNXI_IR_CLK          (SUNXI_IR_BASE_CLK / 64)
79 /* Sample period in ns */
80 #define SUNXI_IR_SAMPLE       (1000000000ul / SUNXI_IR_CLK)
81 /* Noise threshold in samples  */
82 #define SUNXI_IR_RXNOISE      1
83 /* Idle Threshold in samples */
84 #define SUNXI_IR_RXIDLE       20
85 /* Time after which device stops sending data in ms */
86 #define SUNXI_IR_TIMEOUT      120
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 	DEFINE_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_RXINT_RAI_EN | REG_RXINT_RPEI_EN)) {
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) * SUNXI_IR_SAMPLE;
126 			ir_raw_event_store_with_filter(ir->rc, &rawir);
127 		}
128 	}
129 
130 	if (status & REG_RXINT_ROI_EN) {
131 		ir_raw_event_reset(ir->rc);
132 	} else if (status & REG_RXINT_RPEI_EN) {
133 		ir_raw_event_set_idle(ir->rc, true);
134 		ir_raw_event_handle(ir->rc);
135 	}
136 
137 	spin_unlock(&ir->ir_lock);
138 
139 	return IRQ_HANDLED;
140 }
141 
142 static int sunxi_ir_probe(struct platform_device *pdev)
143 {
144 	int ret = 0;
145 	unsigned long tmp = 0;
146 
147 	struct device *dev = &pdev->dev;
148 	struct device_node *dn = dev->of_node;
149 	struct resource *res;
150 	struct sunxi_ir *ir;
151 
152 	ir = devm_kzalloc(dev, sizeof(struct sunxi_ir), GFP_KERNEL);
153 	if (!ir)
154 		return -ENOMEM;
155 
156 	spin_lock_init(&ir->ir_lock);
157 
158 	if (of_device_is_compatible(dn, "allwinner,sun5i-a13-ir"))
159 		ir->fifo_size = 64;
160 	else
161 		ir->fifo_size = 16;
162 
163 	/* Clock */
164 	ir->apb_clk = devm_clk_get(dev, "apb");
165 	if (IS_ERR(ir->apb_clk)) {
166 		dev_err(dev, "failed to get a apb clock.\n");
167 		return PTR_ERR(ir->apb_clk);
168 	}
169 	ir->clk = devm_clk_get(dev, "ir");
170 	if (IS_ERR(ir->clk)) {
171 		dev_err(dev, "failed to get a ir clock.\n");
172 		return PTR_ERR(ir->clk);
173 	}
174 
175 	/* Reset (optional) */
176 	ir->rst = devm_reset_control_get_optional(dev, NULL);
177 	if (IS_ERR(ir->rst)) {
178 		ret = PTR_ERR(ir->rst);
179 		if (ret == -EPROBE_DEFER)
180 			return ret;
181 		ir->rst = NULL;
182 	} else {
183 		ret = reset_control_deassert(ir->rst);
184 		if (ret)
185 			return ret;
186 	}
187 
188 	ret = clk_set_rate(ir->clk, SUNXI_IR_BASE_CLK);
189 	if (ret) {
190 		dev_err(dev, "set ir base clock failed!\n");
191 		goto exit_reset_assert;
192 	}
193 
194 	if (clk_prepare_enable(ir->apb_clk)) {
195 		dev_err(dev, "try to enable apb_ir_clk failed\n");
196 		ret = -EINVAL;
197 		goto exit_reset_assert;
198 	}
199 
200 	if (clk_prepare_enable(ir->clk)) {
201 		dev_err(dev, "try to enable ir_clk failed\n");
202 		ret = -EINVAL;
203 		goto exit_clkdisable_apb_clk;
204 	}
205 
206 	/* IO */
207 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
208 	ir->base = devm_ioremap_resource(dev, res);
209 	if (IS_ERR(ir->base)) {
210 		dev_err(dev, "failed to map registers\n");
211 		ret = PTR_ERR(ir->base);
212 		goto exit_clkdisable_clk;
213 	}
214 
215 	ir->rc = rc_allocate_device(RC_DRIVER_IR_RAW);
216 	if (!ir->rc) {
217 		dev_err(dev, "failed to allocate device\n");
218 		ret = -ENOMEM;
219 		goto exit_clkdisable_clk;
220 	}
221 
222 	ir->rc->priv = ir;
223 	ir->rc->input_name = SUNXI_IR_DEV;
224 	ir->rc->input_phys = "sunxi-ir/input0";
225 	ir->rc->input_id.bustype = BUS_HOST;
226 	ir->rc->input_id.vendor = 0x0001;
227 	ir->rc->input_id.product = 0x0001;
228 	ir->rc->input_id.version = 0x0100;
229 	ir->map_name = of_get_property(dn, "linux,rc-map-name", NULL);
230 	ir->rc->map_name = ir->map_name ?: RC_MAP_EMPTY;
231 	ir->rc->dev.parent = dev;
232 	ir->rc->allowed_protocols = RC_BIT_ALL_IR_DECODER;
233 	ir->rc->rx_resolution = SUNXI_IR_SAMPLE;
234 	ir->rc->timeout = MS_TO_NS(SUNXI_IR_TIMEOUT);
235 	ir->rc->driver_name = SUNXI_IR_DEV;
236 
237 	ret = rc_register_device(ir->rc);
238 	if (ret) {
239 		dev_err(dev, "failed to register rc device\n");
240 		goto exit_free_dev;
241 	}
242 
243 	platform_set_drvdata(pdev, ir);
244 
245 	/* IRQ */
246 	ir->irq = platform_get_irq(pdev, 0);
247 	if (ir->irq < 0) {
248 		dev_err(dev, "no irq resource\n");
249 		ret = ir->irq;
250 		goto exit_free_dev;
251 	}
252 
253 	ret = devm_request_irq(dev, ir->irq, sunxi_ir_irq, 0, SUNXI_IR_DEV, ir);
254 	if (ret) {
255 		dev_err(dev, "failed request irq\n");
256 		goto exit_free_dev;
257 	}
258 
259 	/* Enable CIR Mode */
260 	writel(REG_CTL_MD, ir->base+SUNXI_IR_CTL_REG);
261 
262 	/* Set noise threshold and idle threshold */
263 	writel(REG_CIR_NTHR(SUNXI_IR_RXNOISE)|REG_CIR_ITHR(SUNXI_IR_RXIDLE),
264 	       ir->base + SUNXI_IR_CIR_REG);
265 
266 	/* Invert Input Signal */
267 	writel(REG_RXCTL_RPPI, ir->base + SUNXI_IR_RXCTL_REG);
268 
269 	/* Clear All Rx Interrupt Status */
270 	writel(REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
271 
272 	/*
273 	 * Enable IRQ on overflow, packet end, FIFO available with trigger
274 	 * level
275 	 */
276 	writel(REG_RXINT_ROI_EN | REG_RXINT_RPEI_EN |
277 	       REG_RXINT_RAI_EN | REG_RXINT_RAL(ir->fifo_size / 2 - 1),
278 	       ir->base + SUNXI_IR_RXINT_REG);
279 
280 	/* Enable IR Module */
281 	tmp = readl(ir->base + SUNXI_IR_CTL_REG);
282 	writel(tmp | REG_CTL_GEN | REG_CTL_RXEN, ir->base + SUNXI_IR_CTL_REG);
283 
284 	dev_info(dev, "initialized sunXi IR driver\n");
285 	return 0;
286 
287 exit_free_dev:
288 	rc_free_device(ir->rc);
289 exit_clkdisable_clk:
290 	clk_disable_unprepare(ir->clk);
291 exit_clkdisable_apb_clk:
292 	clk_disable_unprepare(ir->apb_clk);
293 exit_reset_assert:
294 	if (ir->rst)
295 		reset_control_assert(ir->rst);
296 
297 	return ret;
298 }
299 
300 static int sunxi_ir_remove(struct platform_device *pdev)
301 {
302 	unsigned long flags;
303 	struct sunxi_ir *ir = platform_get_drvdata(pdev);
304 
305 	clk_disable_unprepare(ir->clk);
306 	clk_disable_unprepare(ir->apb_clk);
307 	if (ir->rst)
308 		reset_control_assert(ir->rst);
309 
310 	spin_lock_irqsave(&ir->ir_lock, flags);
311 	/* disable IR IRQ */
312 	writel(0, ir->base + SUNXI_IR_RXINT_REG);
313 	/* clear All Rx Interrupt Status */
314 	writel(REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
315 	/* disable IR */
316 	writel(0, ir->base + SUNXI_IR_CTL_REG);
317 	spin_unlock_irqrestore(&ir->ir_lock, flags);
318 
319 	rc_unregister_device(ir->rc);
320 	return 0;
321 }
322 
323 static const struct of_device_id sunxi_ir_match[] = {
324 	{ .compatible = "allwinner,sun4i-a10-ir", },
325 	{ .compatible = "allwinner,sun5i-a13-ir", },
326 	{},
327 };
328 MODULE_DEVICE_TABLE(of, sunxi_ir_match);
329 
330 static struct platform_driver sunxi_ir_driver = {
331 	.probe          = sunxi_ir_probe,
332 	.remove         = sunxi_ir_remove,
333 	.driver = {
334 		.name = SUNXI_IR_DEV,
335 		.of_match_table = sunxi_ir_match,
336 	},
337 };
338 
339 module_platform_driver(sunxi_ir_driver);
340 
341 MODULE_DESCRIPTION("Allwinner sunXi IR controller driver");
342 MODULE_AUTHOR("Alexsey Shestacov <wingrime@linux-sunxi.org>");
343 MODULE_LICENSE("GPL");
344