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 */
87struct sunxi_ir_quirks {
88	bool		has_reset;
89	int		fifo_size;
90};
91
92struct 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
104static 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	} else {
141		ir_raw_event_handle(ir->rc);
142	}
143
144	spin_unlock(&ir->ir_lock);
145
146	return IRQ_HANDLED;
147}
148
149static int sunxi_ir_probe(struct platform_device *pdev)
150{
151	int ret = 0;
152	unsigned long tmp = 0;
153
154	struct device *dev = &pdev->dev;
155	struct device_node *dn = dev->of_node;
156	const struct sunxi_ir_quirks *quirks;
157	struct resource *res;
158	struct sunxi_ir *ir;
159	u32 b_clk_freq = SUNXI_IR_BASE_CLK;
160
161	ir = devm_kzalloc(dev, sizeof(struct sunxi_ir), GFP_KERNEL);
162	if (!ir)
163		return -ENOMEM;
164
165	quirks = of_device_get_match_data(&pdev->dev);
166	if (!quirks) {
167		dev_err(&pdev->dev, "Failed to determine the quirks to use\n");
168		return -ENODEV;
169	}
170
171	spin_lock_init(&ir->ir_lock);
172
173	ir->fifo_size = quirks->fifo_size;
174
175	/* Clock */
176	ir->apb_clk = devm_clk_get(dev, "apb");
177	if (IS_ERR(ir->apb_clk)) {
178		dev_err(dev, "failed to get a apb clock.\n");
179		return PTR_ERR(ir->apb_clk);
180	}
181	ir->clk = devm_clk_get(dev, "ir");
182	if (IS_ERR(ir->clk)) {
183		dev_err(dev, "failed to get a ir clock.\n");
184		return PTR_ERR(ir->clk);
185	}
186
187	/* Base clock frequency (optional) */
188	of_property_read_u32(dn, "clock-frequency", &b_clk_freq);
189
190	/* Reset */
191	if (quirks->has_reset) {
192		ir->rst = devm_reset_control_get_exclusive(dev, NULL);
193		if (IS_ERR(ir->rst))
194			return PTR_ERR(ir->rst);
195		ret = reset_control_deassert(ir->rst);
196		if (ret)
197			return ret;
198	}
199
200	ret = clk_set_rate(ir->clk, b_clk_freq);
201	if (ret) {
202		dev_err(dev, "set ir base clock failed!\n");
203		goto exit_reset_assert;
204	}
205	dev_dbg(dev, "set base clock frequency to %d Hz.\n", b_clk_freq);
206
207	if (clk_prepare_enable(ir->apb_clk)) {
208		dev_err(dev, "try to enable apb_ir_clk failed\n");
209		ret = -EINVAL;
210		goto exit_reset_assert;
211	}
212
213	if (clk_prepare_enable(ir->clk)) {
214		dev_err(dev, "try to enable ir_clk failed\n");
215		ret = -EINVAL;
216		goto exit_clkdisable_apb_clk;
217	}
218
219	/* IO */
220	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
221	ir->base = devm_ioremap_resource(dev, res);
222	if (IS_ERR(ir->base)) {
223		ret = PTR_ERR(ir->base);
224		goto exit_clkdisable_clk;
225	}
226
227	ir->rc = rc_allocate_device(RC_DRIVER_IR_RAW);
228	if (!ir->rc) {
229		dev_err(dev, "failed to allocate device\n");
230		ret = -ENOMEM;
231		goto exit_clkdisable_clk;
232	}
233
234	ir->rc->priv = ir;
235	ir->rc->device_name = SUNXI_IR_DEV;
236	ir->rc->input_phys = "sunxi-ir/input0";
237	ir->rc->input_id.bustype = BUS_HOST;
238	ir->rc->input_id.vendor = 0x0001;
239	ir->rc->input_id.product = 0x0001;
240	ir->rc->input_id.version = 0x0100;
241	ir->map_name = of_get_property(dn, "linux,rc-map-name", NULL);
242	ir->rc->map_name = ir->map_name ?: RC_MAP_EMPTY;
243	ir->rc->dev.parent = dev;
244	ir->rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
245	/* Frequency after IR internal divider with sample period in ns */
246	ir->rc->rx_resolution = (USEC_PER_SEC / (b_clk_freq / 64));
247	ir->rc->timeout = MS_TO_US(SUNXI_IR_TIMEOUT);
248	ir->rc->driver_name = SUNXI_IR_DEV;
249
250	ret = rc_register_device(ir->rc);
251	if (ret) {
252		dev_err(dev, "failed to register rc device\n");
253		goto exit_free_dev;
254	}
255
256	platform_set_drvdata(pdev, ir);
257
258	/* IRQ */
259	ir->irq = platform_get_irq(pdev, 0);
260	if (ir->irq < 0) {
261		ret = ir->irq;
262		goto exit_free_dev;
263	}
264
265	ret = devm_request_irq(dev, ir->irq, sunxi_ir_irq, 0, SUNXI_IR_DEV, ir);
266	if (ret) {
267		dev_err(dev, "failed request irq\n");
268		goto exit_free_dev;
269	}
270
271	/* Enable CIR Mode */
272	writel(REG_CTL_MD, ir->base+SUNXI_IR_CTL_REG);
273
274	/* Set noise threshold and idle threshold */
275	writel(REG_CIR_NTHR(SUNXI_IR_RXNOISE)|REG_CIR_ITHR(SUNXI_IR_RXIDLE),
276	       ir->base + SUNXI_IR_CIR_REG);
277
278	/* Invert Input Signal */
279	writel(REG_RXCTL_RPPI, ir->base + SUNXI_IR_RXCTL_REG);
280
281	/* Clear All Rx Interrupt Status */
282	writel(REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
283
284	/*
285	 * Enable IRQ on overflow, packet end, FIFO available with trigger
286	 * level
287	 */
288	writel(REG_RXINT_ROI_EN | REG_RXINT_RPEI_EN |
289	       REG_RXINT_RAI_EN | REG_RXINT_RAL(ir->fifo_size / 2 - 1),
290	       ir->base + SUNXI_IR_RXINT_REG);
291
292	/* Enable IR Module */
293	tmp = readl(ir->base + SUNXI_IR_CTL_REG);
294	writel(tmp | REG_CTL_GEN | REG_CTL_RXEN, ir->base + SUNXI_IR_CTL_REG);
295
296	dev_info(dev, "initialized sunXi IR driver\n");
297	return 0;
298
299exit_free_dev:
300	rc_free_device(ir->rc);
301exit_clkdisable_clk:
302	clk_disable_unprepare(ir->clk);
303exit_clkdisable_apb_clk:
304	clk_disable_unprepare(ir->apb_clk);
305exit_reset_assert:
306	reset_control_assert(ir->rst);
307
308	return ret;
309}
310
311static int sunxi_ir_remove(struct platform_device *pdev)
312{
313	unsigned long flags;
314	struct sunxi_ir *ir = platform_get_drvdata(pdev);
315
316	clk_disable_unprepare(ir->clk);
317	clk_disable_unprepare(ir->apb_clk);
318	reset_control_assert(ir->rst);
319
320	spin_lock_irqsave(&ir->ir_lock, flags);
321	/* disable IR IRQ */
322	writel(0, ir->base + SUNXI_IR_RXINT_REG);
323	/* clear All Rx Interrupt Status */
324	writel(REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
325	/* disable IR */
326	writel(0, ir->base + SUNXI_IR_CTL_REG);
327	spin_unlock_irqrestore(&ir->ir_lock, flags);
328
329	rc_unregister_device(ir->rc);
330	return 0;
331}
332
333static const struct sunxi_ir_quirks sun4i_a10_ir_quirks = {
334	.has_reset = false,
335	.fifo_size = 16,
336};
337
338static const struct sunxi_ir_quirks sun5i_a13_ir_quirks = {
339	.has_reset = false,
340	.fifo_size = 64,
341};
342
343static const struct sunxi_ir_quirks sun6i_a31_ir_quirks = {
344	.has_reset = true,
345	.fifo_size = 64,
346};
347
348static const struct of_device_id sunxi_ir_match[] = {
349	{
350		.compatible = "allwinner,sun4i-a10-ir",
351		.data = &sun4i_a10_ir_quirks,
352	},
353	{
354		.compatible = "allwinner,sun5i-a13-ir",
355		.data = &sun5i_a13_ir_quirks,
356	},
357	{
358		.compatible = "allwinner,sun6i-a31-ir",
359		.data = &sun6i_a31_ir_quirks,
360	},
361	{}
362};
363MODULE_DEVICE_TABLE(of, sunxi_ir_match);
364
365static struct platform_driver sunxi_ir_driver = {
366	.probe          = sunxi_ir_probe,
367	.remove         = sunxi_ir_remove,
368	.driver = {
369		.name = SUNXI_IR_DEV,
370		.of_match_table = sunxi_ir_match,
371	},
372};
373
374module_platform_driver(sunxi_ir_driver);
375
376MODULE_DESCRIPTION("Allwinner sunXi IR controller driver");
377MODULE_AUTHOR("Alexsey Shestacov <wingrime@linux-sunxi.org>");
378MODULE_LICENSE("GPL");
379