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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 <media/rc-core.h>
27
28#define SUNXI_IR_DEV "sunxi-ir"
29
30/* Registers */
31/* IR Control */
32#define SUNXI_IR_CTL_REG      0x00
33/* Global Enable */
34#define REG_CTL_GEN			BIT(0)
35/* RX block enable */
36#define REG_CTL_RXEN			BIT(1)
37/* CIR mode */
38#define REG_CTL_MD			(BIT(4) | BIT(5))
39
40/* Rx Config */
41#define SUNXI_IR_RXCTL_REG    0x10
42/* Pulse Polarity Invert flag */
43#define REG_RXCTL_RPPI			BIT(2)
44
45/* Rx Data */
46#define SUNXI_IR_RXFIFO_REG   0x20
47
48/* Rx Interrupt Enable */
49#define SUNXI_IR_RXINT_REG    0x2C
50/* Rx FIFO Overflow */
51#define REG_RXINT_ROI_EN		BIT(0)
52/* Rx Packet End */
53#define REG_RXINT_RPEI_EN		BIT(1)
54/* Rx FIFO Data Available */
55#define REG_RXINT_RAI_EN		BIT(4)
56
57/* Rx FIFO available byte level */
58#define REG_RXINT_RAL(val)    (((val) << 8) & (GENMASK(11, 8)))
59
60/* Rx Interrupt Status */
61#define SUNXI_IR_RXSTA_REG    0x30
62/* RX FIFO Get Available Counter */
63#define REG_RXSTA_GET_AC(val) (((val) >> 8) & (GENMASK(5, 0)))
64/* Clear all interrupt status value */
65#define REG_RXSTA_CLEARALL    0xff
66
67/* IR Sample Config */
68#define SUNXI_IR_CIR_REG      0x34
69/* CIR_REG register noise threshold */
70#define REG_CIR_NTHR(val)    (((val) << 2) & (GENMASK(7, 2)))
71/* CIR_REG register idle threshold */
72#define REG_CIR_ITHR(val)    (((val) << 8) & (GENMASK(15, 8)))
73
74/* Hardware supported fifo size */
75#define SUNXI_IR_FIFO_SIZE    16
76/* How many messages in FIFO trigger IRQ */
77#define TRIGGER_LEVEL         8
78/* Required frequency for IR0 or IR1 clock in CIR mode */
79#define SUNXI_IR_BASE_CLK     8000000
80/* Frequency after IR internal divider  */
81#define SUNXI_IR_CLK          (SUNXI_IR_BASE_CLK / 64)
82/* Sample period in ns */
83#define SUNXI_IR_SAMPLE       (1000000000ul / SUNXI_IR_CLK)
84/* Noise threshold in samples  */
85#define SUNXI_IR_RXNOISE      1
86/* Idle Threshold in samples */
87#define SUNXI_IR_RXIDLE       20
88/* Time after which device stops sending data in ms */
89#define SUNXI_IR_TIMEOUT      120
90
91struct sunxi_ir {
92	spinlock_t      ir_lock;
93	struct rc_dev   *rc;
94	void __iomem    *base;
95	int             irq;
96	struct clk      *clk;
97	struct clk      *apb_clk;
98	const char      *map_name;
99};
100
101static irqreturn_t sunxi_ir_irq(int irqno, void *dev_id)
102{
103	unsigned long status;
104	unsigned char dt;
105	unsigned int cnt, rc;
106	struct sunxi_ir *ir = dev_id;
107	DEFINE_IR_RAW_EVENT(rawir);
108
109	spin_lock(&ir->ir_lock);
110
111	status = readl(ir->base + SUNXI_IR_RXSTA_REG);
112
113	/* clean all pending statuses */
114	writel(status | REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
115
116	if (status & REG_RXINT_RAI_EN) {
117		/* How many messages in fifo */
118		rc  = REG_RXSTA_GET_AC(status);
119		/* Sanity check */
120		rc = rc > SUNXI_IR_FIFO_SIZE ? SUNXI_IR_FIFO_SIZE : rc;
121		/* If we have data */
122		for (cnt = 0; cnt < rc; cnt++) {
123			/* for each bit in fifo */
124			dt = readb(ir->base + SUNXI_IR_RXFIFO_REG);
125			rawir.pulse = (dt & 0x80) != 0;
126			rawir.duration = ((dt & 0x7f) + 1) * SUNXI_IR_SAMPLE;
127			ir_raw_event_store_with_filter(ir->rc, &rawir);
128		}
129	}
130
131	if (status & REG_RXINT_ROI_EN) {
132		ir_raw_event_reset(ir->rc);
133	} else if (status & REG_RXINT_RPEI_EN) {
134		ir_raw_event_set_idle(ir->rc, true);
135		ir_raw_event_handle(ir->rc);
136	}
137
138	spin_unlock(&ir->ir_lock);
139
140	return IRQ_HANDLED;
141}
142
143static int sunxi_ir_probe(struct platform_device *pdev)
144{
145	int ret = 0;
146	unsigned long tmp = 0;
147
148	struct device *dev = &pdev->dev;
149	struct device_node *dn = dev->of_node;
150	struct resource *res;
151	struct sunxi_ir *ir;
152
153	ir = devm_kzalloc(dev, sizeof(struct sunxi_ir), GFP_KERNEL);
154	if (!ir)
155		return -ENOMEM;
156
157	/* Clock */
158	ir->apb_clk = devm_clk_get(dev, "apb");
159	if (IS_ERR(ir->apb_clk)) {
160		dev_err(dev, "failed to get a apb clock.\n");
161		return PTR_ERR(ir->apb_clk);
162	}
163	ir->clk = devm_clk_get(dev, "ir");
164	if (IS_ERR(ir->clk)) {
165		dev_err(dev, "failed to get a ir clock.\n");
166		return PTR_ERR(ir->clk);
167	}
168
169	ret = clk_set_rate(ir->clk, SUNXI_IR_BASE_CLK);
170	if (ret) {
171		dev_err(dev, "set ir base clock failed!\n");
172		return ret;
173	}
174
175	if (clk_prepare_enable(ir->apb_clk)) {
176		dev_err(dev, "try to enable apb_ir_clk failed\n");
177		return -EINVAL;
178	}
179
180	if (clk_prepare_enable(ir->clk)) {
181		dev_err(dev, "try to enable ir_clk failed\n");
182		ret = -EINVAL;
183		goto exit_clkdisable_apb_clk;
184	}
185
186	/* IO */
187	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
188	ir->base = devm_ioremap_resource(dev, res);
189	if (IS_ERR(ir->base)) {
190		dev_err(dev, "failed to map registers\n");
191		ret = PTR_ERR(ir->base);
192		goto exit_clkdisable_clk;
193	}
194
195	ir->rc = rc_allocate_device();
196	if (!ir->rc) {
197		dev_err(dev, "failed to allocate device\n");
198		ret = -ENOMEM;
199		goto exit_clkdisable_clk;
200	}
201
202	ir->rc->priv = ir;
203	ir->rc->input_name = SUNXI_IR_DEV;
204	ir->rc->input_phys = "sunxi-ir/input0";
205	ir->rc->input_id.bustype = BUS_HOST;
206	ir->rc->input_id.vendor = 0x0001;
207	ir->rc->input_id.product = 0x0001;
208	ir->rc->input_id.version = 0x0100;
209	ir->map_name = of_get_property(dn, "linux,rc-map-name", NULL);
210	ir->rc->map_name = ir->map_name ?: RC_MAP_EMPTY;
211	ir->rc->dev.parent = dev;
212	ir->rc->driver_type = RC_DRIVER_IR_RAW;
213	ir->rc->allowed_protocols = RC_BIT_ALL;
214	ir->rc->rx_resolution = SUNXI_IR_SAMPLE;
215	ir->rc->timeout = MS_TO_NS(SUNXI_IR_TIMEOUT);
216	ir->rc->driver_name = SUNXI_IR_DEV;
217
218	ret = rc_register_device(ir->rc);
219	if (ret) {
220		dev_err(dev, "failed to register rc device\n");
221		goto exit_free_dev;
222	}
223
224	platform_set_drvdata(pdev, ir);
225
226	/* IRQ */
227	ir->irq = platform_get_irq(pdev, 0);
228	if (ir->irq < 0) {
229		dev_err(dev, "no irq resource\n");
230		ret = ir->irq;
231		goto exit_free_dev;
232	}
233
234	ret = devm_request_irq(dev, ir->irq, sunxi_ir_irq, 0, SUNXI_IR_DEV, ir);
235	if (ret) {
236		dev_err(dev, "failed request irq\n");
237		goto exit_free_dev;
238	}
239
240	/* Enable CIR Mode */
241	writel(REG_CTL_MD, ir->base+SUNXI_IR_CTL_REG);
242
243	/* Set noise threshold and idle threshold */
244	writel(REG_CIR_NTHR(SUNXI_IR_RXNOISE)|REG_CIR_ITHR(SUNXI_IR_RXIDLE),
245	       ir->base + SUNXI_IR_CIR_REG);
246
247	/* Invert Input Signal */
248	writel(REG_RXCTL_RPPI, ir->base + SUNXI_IR_RXCTL_REG);
249
250	/* Clear All Rx Interrupt Status */
251	writel(REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
252
253	/*
254	 * Enable IRQ on overflow, packet end, FIFO available with trigger
255	 * level
256	 */
257	writel(REG_RXINT_ROI_EN | REG_RXINT_RPEI_EN |
258	       REG_RXINT_RAI_EN | REG_RXINT_RAL(TRIGGER_LEVEL - 1),
259	       ir->base + SUNXI_IR_RXINT_REG);
260
261	/* Enable IR Module */
262	tmp = readl(ir->base + SUNXI_IR_CTL_REG);
263	writel(tmp | REG_CTL_GEN | REG_CTL_RXEN, ir->base + SUNXI_IR_CTL_REG);
264
265	dev_info(dev, "initialized sunXi IR driver\n");
266	return 0;
267
268exit_free_dev:
269	rc_free_device(ir->rc);
270exit_clkdisable_clk:
271	clk_disable_unprepare(ir->clk);
272exit_clkdisable_apb_clk:
273	clk_disable_unprepare(ir->apb_clk);
274
275	return ret;
276}
277
278static int sunxi_ir_remove(struct platform_device *pdev)
279{
280	unsigned long flags;
281	struct sunxi_ir *ir = platform_get_drvdata(pdev);
282
283	clk_disable_unprepare(ir->clk);
284	clk_disable_unprepare(ir->apb_clk);
285
286	spin_lock_irqsave(&ir->ir_lock, flags);
287	/* disable IR IRQ */
288	writel(0, ir->base + SUNXI_IR_RXINT_REG);
289	/* clear All Rx Interrupt Status */
290	writel(REG_RXSTA_CLEARALL, ir->base + SUNXI_IR_RXSTA_REG);
291	/* disable IR */
292	writel(0, ir->base + SUNXI_IR_CTL_REG);
293	spin_unlock_irqrestore(&ir->ir_lock, flags);
294
295	rc_unregister_device(ir->rc);
296	return 0;
297}
298
299static const struct of_device_id sunxi_ir_match[] = {
300	{ .compatible = "allwinner,sun4i-a10-ir", },
301	{},
302};
303
304static struct platform_driver sunxi_ir_driver = {
305	.probe          = sunxi_ir_probe,
306	.remove         = sunxi_ir_remove,
307	.driver = {
308		.name = SUNXI_IR_DEV,
309		.owner = THIS_MODULE,
310		.of_match_table = sunxi_ir_match,
311	},
312};
313
314module_platform_driver(sunxi_ir_driver);
315
316MODULE_DESCRIPTION("Allwinner sunXi IR controller driver");
317MODULE_AUTHOR("Alexsey Shestacov <wingrime@linux-sunxi.org>");
318MODULE_LICENSE("GPL");
319