xref: /linux/drivers/media/rc/sunxi-cir.c (revision e9f0878c4b2004ac19581274c1ae4c61ae3ca70e)
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 (default) */
76 #define SUNXI_IR_BASE_CLK     8000000
77 /* Noise threshold in samples  */
78 #define SUNXI_IR_RXNOISE      1
79 /* Idle Threshold in samples */
80 #define SUNXI_IR_RXIDLE       20
81 /* Time after which device stops sending data in ms */
82 #define SUNXI_IR_TIMEOUT      120
83 
84 struct sunxi_ir {
85 	spinlock_t      ir_lock;
86 	struct rc_dev   *rc;
87 	void __iomem    *base;
88 	int             irq;
89 	int		fifo_size;
90 	struct clk      *clk;
91 	struct clk      *apb_clk;
92 	struct reset_control *rst;
93 	const char      *map_name;
94 };
95 
96 static irqreturn_t sunxi_ir_irq(int irqno, void *dev_id)
97 {
98 	unsigned long status;
99 	unsigned char dt;
100 	unsigned int cnt, rc;
101 	struct sunxi_ir *ir = dev_id;
102 	DEFINE_IR_RAW_EVENT(rawir);
103 
104 	spin_lock(&ir->ir_lock);
105 
106 	status = readl(ir->base + SUNXI_IR_RXSTA_REG);
107 
108 	/* clean all pending statuses */
109 	writel(status | REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
110 
111 	if (status & (REG_RXINT_RAI_EN | REG_RXINT_RPEI_EN)) {
112 		/* How many messages in fifo */
113 		rc  = REG_RXSTA_GET_AC(status);
114 		/* Sanity check */
115 		rc = rc > ir->fifo_size ? ir->fifo_size : rc;
116 		/* If we have data */
117 		for (cnt = 0; cnt < rc; cnt++) {
118 			/* for each bit in fifo */
119 			dt = readb(ir->base + SUNXI_IR_RXFIFO_REG);
120 			rawir.pulse = (dt & 0x80) != 0;
121 			rawir.duration = ((dt & 0x7f) + 1) *
122 					 ir->rc->rx_resolution;
123 			ir_raw_event_store_with_filter(ir->rc, &rawir);
124 		}
125 	}
126 
127 	if (status & REG_RXINT_ROI_EN) {
128 		ir_raw_event_reset(ir->rc);
129 	} else if (status & REG_RXINT_RPEI_EN) {
130 		ir_raw_event_set_idle(ir->rc, true);
131 		ir_raw_event_handle(ir->rc);
132 	}
133 
134 	spin_unlock(&ir->ir_lock);
135 
136 	return IRQ_HANDLED;
137 }
138 
139 static int sunxi_ir_probe(struct platform_device *pdev)
140 {
141 	int ret = 0;
142 	unsigned long tmp = 0;
143 
144 	struct device *dev = &pdev->dev;
145 	struct device_node *dn = dev->of_node;
146 	struct resource *res;
147 	struct sunxi_ir *ir;
148 	u32 b_clk_freq = SUNXI_IR_BASE_CLK;
149 
150 	ir = devm_kzalloc(dev, sizeof(struct sunxi_ir), GFP_KERNEL);
151 	if (!ir)
152 		return -ENOMEM;
153 
154 	spin_lock_init(&ir->ir_lock);
155 
156 	if (of_device_is_compatible(dn, "allwinner,sun5i-a13-ir"))
157 		ir->fifo_size = 64;
158 	else
159 		ir->fifo_size = 16;
160 
161 	/* Clock */
162 	ir->apb_clk = devm_clk_get(dev, "apb");
163 	if (IS_ERR(ir->apb_clk)) {
164 		dev_err(dev, "failed to get a apb clock.\n");
165 		return PTR_ERR(ir->apb_clk);
166 	}
167 	ir->clk = devm_clk_get(dev, "ir");
168 	if (IS_ERR(ir->clk)) {
169 		dev_err(dev, "failed to get a ir clock.\n");
170 		return PTR_ERR(ir->clk);
171 	}
172 
173 	/* Base clock frequency (optional) */
174 	of_property_read_u32(dn, "clock-frequency", &b_clk_freq);
175 
176 	/* Reset (optional) */
177 	ir->rst = devm_reset_control_get_optional_exclusive(dev, NULL);
178 	if (IS_ERR(ir->rst))
179 		return PTR_ERR(ir->rst);
180 	ret = reset_control_deassert(ir->rst);
181 	if (ret)
182 		return ret;
183 
184 	ret = clk_set_rate(ir->clk, b_clk_freq);
185 	if (ret) {
186 		dev_err(dev, "set ir base clock failed!\n");
187 		goto exit_reset_assert;
188 	}
189 	dev_dbg(dev, "set base clock frequency to %d Hz.\n", b_clk_freq);
190 
191 	if (clk_prepare_enable(ir->apb_clk)) {
192 		dev_err(dev, "try to enable apb_ir_clk failed\n");
193 		ret = -EINVAL;
194 		goto exit_reset_assert;
195 	}
196 
197 	if (clk_prepare_enable(ir->clk)) {
198 		dev_err(dev, "try to enable ir_clk failed\n");
199 		ret = -EINVAL;
200 		goto exit_clkdisable_apb_clk;
201 	}
202 
203 	/* IO */
204 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
205 	ir->base = devm_ioremap_resource(dev, res);
206 	if (IS_ERR(ir->base)) {
207 		dev_err(dev, "failed to map registers\n");
208 		ret = PTR_ERR(ir->base);
209 		goto exit_clkdisable_clk;
210 	}
211 
212 	ir->rc = rc_allocate_device(RC_DRIVER_IR_RAW);
213 	if (!ir->rc) {
214 		dev_err(dev, "failed to allocate device\n");
215 		ret = -ENOMEM;
216 		goto exit_clkdisable_clk;
217 	}
218 
219 	ir->rc->priv = ir;
220 	ir->rc->device_name = SUNXI_IR_DEV;
221 	ir->rc->input_phys = "sunxi-ir/input0";
222 	ir->rc->input_id.bustype = BUS_HOST;
223 	ir->rc->input_id.vendor = 0x0001;
224 	ir->rc->input_id.product = 0x0001;
225 	ir->rc->input_id.version = 0x0100;
226 	ir->map_name = of_get_property(dn, "linux,rc-map-name", NULL);
227 	ir->rc->map_name = ir->map_name ?: RC_MAP_EMPTY;
228 	ir->rc->dev.parent = dev;
229 	ir->rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
230 	/* Frequency after IR internal divider with sample period in ns */
231 	ir->rc->rx_resolution = (1000000000ul / (b_clk_freq / 64));
232 	ir->rc->timeout = MS_TO_NS(SUNXI_IR_TIMEOUT);
233 	ir->rc->driver_name = SUNXI_IR_DEV;
234 
235 	ret = rc_register_device(ir->rc);
236 	if (ret) {
237 		dev_err(dev, "failed to register rc device\n");
238 		goto exit_free_dev;
239 	}
240 
241 	platform_set_drvdata(pdev, ir);
242 
243 	/* IRQ */
244 	ir->irq = platform_get_irq(pdev, 0);
245 	if (ir->irq < 0) {
246 		dev_err(dev, "no irq resource\n");
247 		ret = ir->irq;
248 		goto exit_free_dev;
249 	}
250 
251 	ret = devm_request_irq(dev, ir->irq, sunxi_ir_irq, 0, SUNXI_IR_DEV, ir);
252 	if (ret) {
253 		dev_err(dev, "failed request irq\n");
254 		goto exit_free_dev;
255 	}
256 
257 	/* Enable CIR Mode */
258 	writel(REG_CTL_MD, ir->base+SUNXI_IR_CTL_REG);
259 
260 	/* Set noise threshold and idle threshold */
261 	writel(REG_CIR_NTHR(SUNXI_IR_RXNOISE)|REG_CIR_ITHR(SUNXI_IR_RXIDLE),
262 	       ir->base + SUNXI_IR_CIR_REG);
263 
264 	/* Invert Input Signal */
265 	writel(REG_RXCTL_RPPI, ir->base + SUNXI_IR_RXCTL_REG);
266 
267 	/* Clear All Rx Interrupt Status */
268 	writel(REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
269 
270 	/*
271 	 * Enable IRQ on overflow, packet end, FIFO available with trigger
272 	 * level
273 	 */
274 	writel(REG_RXINT_ROI_EN | REG_RXINT_RPEI_EN |
275 	       REG_RXINT_RAI_EN | REG_RXINT_RAL(ir->fifo_size / 2 - 1),
276 	       ir->base + SUNXI_IR_RXINT_REG);
277 
278 	/* Enable IR Module */
279 	tmp = readl(ir->base + SUNXI_IR_CTL_REG);
280 	writel(tmp | REG_CTL_GEN | REG_CTL_RXEN, ir->base + SUNXI_IR_CTL_REG);
281 
282 	dev_info(dev, "initialized sunXi IR driver\n");
283 	return 0;
284 
285 exit_free_dev:
286 	rc_free_device(ir->rc);
287 exit_clkdisable_clk:
288 	clk_disable_unprepare(ir->clk);
289 exit_clkdisable_apb_clk:
290 	clk_disable_unprepare(ir->apb_clk);
291 exit_reset_assert:
292 	reset_control_assert(ir->rst);
293 
294 	return ret;
295 }
296 
297 static int sunxi_ir_remove(struct platform_device *pdev)
298 {
299 	unsigned long flags;
300 	struct sunxi_ir *ir = platform_get_drvdata(pdev);
301 
302 	clk_disable_unprepare(ir->clk);
303 	clk_disable_unprepare(ir->apb_clk);
304 	reset_control_assert(ir->rst);
305 
306 	spin_lock_irqsave(&ir->ir_lock, flags);
307 	/* disable IR IRQ */
308 	writel(0, ir->base + SUNXI_IR_RXINT_REG);
309 	/* clear All Rx Interrupt Status */
310 	writel(REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
311 	/* disable IR */
312 	writel(0, ir->base + SUNXI_IR_CTL_REG);
313 	spin_unlock_irqrestore(&ir->ir_lock, flags);
314 
315 	rc_unregister_device(ir->rc);
316 	return 0;
317 }
318 
319 static const struct of_device_id sunxi_ir_match[] = {
320 	{ .compatible = "allwinner,sun4i-a10-ir", },
321 	{ .compatible = "allwinner,sun5i-a13-ir", },
322 	{},
323 };
324 MODULE_DEVICE_TABLE(of, sunxi_ir_match);
325 
326 static struct platform_driver sunxi_ir_driver = {
327 	.probe          = sunxi_ir_probe,
328 	.remove         = sunxi_ir_remove,
329 	.driver = {
330 		.name = SUNXI_IR_DEV,
331 		.of_match_table = sunxi_ir_match,
332 	},
333 };
334 
335 module_platform_driver(sunxi_ir_driver);
336 
337 MODULE_DESCRIPTION("Allwinner sunXi IR controller driver");
338 MODULE_AUTHOR("Alexsey Shestacov <wingrime@linux-sunxi.org>");
339 MODULE_LICENSE("GPL");
340