1/*
2 * Driver for Amlogic Meson IR remote receiver
3 *
4 * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * version 2 as published by the Free Software Foundation.
9 *
10 * You should have received a copy of the GNU General Public License
11 * along with this program. If not, see <http://www.gnu.org/licenses/>.
12 */
13
14#include <linux/device.h>
15#include <linux/err.h>
16#include <linux/interrupt.h>
17#include <linux/io.h>
18#include <linux/module.h>
19#include <linux/of_platform.h>
20#include <linux/platform_device.h>
21#include <linux/spinlock.h>
22
23#include <media/rc-core.h>
24
25#define DRIVER_NAME		"meson-ir"
26
27#define IR_DEC_LDR_ACTIVE	0x00
28#define IR_DEC_LDR_IDLE		0x04
29#define IR_DEC_LDR_REPEAT	0x08
30#define IR_DEC_BIT_0		0x0c
31#define IR_DEC_REG0		0x10
32#define IR_DEC_FRAME		0x14
33#define IR_DEC_STATUS		0x18
34#define IR_DEC_REG1		0x1c
35
36#define REG0_RATE_MASK		(BIT(11) - 1)
37
38#define REG1_MODE_MASK		(BIT(7) | BIT(8))
39#define REG1_MODE_NEC		(0 << 7)
40#define REG1_MODE_GENERAL	(2 << 7)
41
42#define REG1_TIME_IV_SHIFT	16
43#define REG1_TIME_IV_MASK	((BIT(13) - 1) << REG1_TIME_IV_SHIFT)
44
45#define REG1_IRQSEL_MASK	(BIT(2) | BIT(3))
46#define REG1_IRQSEL_NEC_MODE	(0 << 2)
47#define REG1_IRQSEL_RISE_FALL	(1 << 2)
48#define REG1_IRQSEL_FALL	(2 << 2)
49#define REG1_IRQSEL_RISE	(3 << 2)
50
51#define REG1_RESET		BIT(0)
52#define REG1_ENABLE		BIT(15)
53
54#define STATUS_IR_DEC_IN	BIT(8)
55
56#define MESON_TRATE		10	/* us */
57
58struct meson_ir {
59	void __iomem	*reg;
60	struct rc_dev	*rc;
61	int		irq;
62	spinlock_t	lock;
63};
64
65static void meson_ir_set_mask(struct meson_ir *ir, unsigned int reg,
66			      u32 mask, u32 value)
67{
68	u32 data;
69
70	data = readl(ir->reg + reg);
71	data &= ~mask;
72	data |= (value & mask);
73	writel(data, ir->reg + reg);
74}
75
76static irqreturn_t meson_ir_irq(int irqno, void *dev_id)
77{
78	struct meson_ir *ir = dev_id;
79	u32 duration;
80	DEFINE_IR_RAW_EVENT(rawir);
81
82	spin_lock(&ir->lock);
83
84	duration = readl(ir->reg + IR_DEC_REG1);
85	duration = (duration & REG1_TIME_IV_MASK) >> REG1_TIME_IV_SHIFT;
86	rawir.duration = US_TO_NS(duration * MESON_TRATE);
87
88	rawir.pulse = !!(readl(ir->reg + IR_DEC_STATUS) & STATUS_IR_DEC_IN);
89
90	ir_raw_event_store_with_filter(ir->rc, &rawir);
91	ir_raw_event_handle(ir->rc);
92
93	spin_unlock(&ir->lock);
94
95	return IRQ_HANDLED;
96}
97
98static int meson_ir_probe(struct platform_device *pdev)
99{
100	struct device *dev = &pdev->dev;
101	struct device_node *node = dev->of_node;
102	struct resource *res;
103	const char *map_name;
104	struct meson_ir *ir;
105	int ret;
106
107	ir = devm_kzalloc(dev, sizeof(struct meson_ir), GFP_KERNEL);
108	if (!ir)
109		return -ENOMEM;
110
111	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
112	ir->reg = devm_ioremap_resource(dev, res);
113	if (IS_ERR(ir->reg)) {
114		dev_err(dev, "failed to map registers\n");
115		return PTR_ERR(ir->reg);
116	}
117
118	ir->irq = platform_get_irq(pdev, 0);
119	if (ir->irq < 0) {
120		dev_err(dev, "no irq resource\n");
121		return ir->irq;
122	}
123
124	ir->rc = rc_allocate_device();
125	if (!ir->rc) {
126		dev_err(dev, "failed to allocate rc device\n");
127		return -ENOMEM;
128	}
129
130	ir->rc->priv = ir;
131	ir->rc->input_name = DRIVER_NAME;
132	ir->rc->input_phys = DRIVER_NAME "/input0";
133	ir->rc->input_id.bustype = BUS_HOST;
134	map_name = of_get_property(node, "linux,rc-map-name", NULL);
135	ir->rc->map_name = map_name ? map_name : RC_MAP_EMPTY;
136	ir->rc->dev.parent = dev;
137	ir->rc->driver_type = RC_DRIVER_IR_RAW;
138	ir->rc->allowed_protocols = RC_BIT_ALL;
139	ir->rc->rx_resolution = US_TO_NS(MESON_TRATE);
140	ir->rc->timeout = MS_TO_NS(200);
141	ir->rc->driver_name = DRIVER_NAME;
142
143	spin_lock_init(&ir->lock);
144	platform_set_drvdata(pdev, ir);
145
146	ret = rc_register_device(ir->rc);
147	if (ret) {
148		dev_err(dev, "failed to register rc device\n");
149		goto out_free;
150	}
151
152	ret = devm_request_irq(dev, ir->irq, meson_ir_irq, 0, "ir-meson", ir);
153	if (ret) {
154		dev_err(dev, "failed to request irq\n");
155		goto out_unreg;
156	}
157
158	/* Reset the decoder */
159	meson_ir_set_mask(ir, IR_DEC_REG1, REG1_RESET, REG1_RESET);
160	meson_ir_set_mask(ir, IR_DEC_REG1, REG1_RESET, 0);
161	/* Set general operation mode */
162	meson_ir_set_mask(ir, IR_DEC_REG1, REG1_MODE_MASK, REG1_MODE_GENERAL);
163	/* Set rate */
164	meson_ir_set_mask(ir, IR_DEC_REG0, REG0_RATE_MASK, MESON_TRATE - 1);
165	/* IRQ on rising and falling edges */
166	meson_ir_set_mask(ir, IR_DEC_REG1, REG1_IRQSEL_MASK,
167			  REG1_IRQSEL_RISE_FALL);
168	/* Enable the decoder */
169	meson_ir_set_mask(ir, IR_DEC_REG1, REG1_ENABLE, REG1_ENABLE);
170
171	dev_info(dev, "receiver initialized\n");
172
173	return 0;
174out_unreg:
175	rc_unregister_device(ir->rc);
176	ir->rc = NULL;
177out_free:
178	rc_free_device(ir->rc);
179
180	return ret;
181}
182
183static int meson_ir_remove(struct platform_device *pdev)
184{
185	struct meson_ir *ir = platform_get_drvdata(pdev);
186	unsigned long flags;
187
188	/* Disable the decoder */
189	spin_lock_irqsave(&ir->lock, flags);
190	meson_ir_set_mask(ir, IR_DEC_REG1, REG1_ENABLE, 0);
191	spin_unlock_irqrestore(&ir->lock, flags);
192
193	rc_unregister_device(ir->rc);
194
195	return 0;
196}
197
198static const struct of_device_id meson_ir_match[] = {
199	{ .compatible = "amlogic,meson6-ir" },
200	{ },
201};
202
203static struct platform_driver meson_ir_driver = {
204	.probe		= meson_ir_probe,
205	.remove		= meson_ir_remove,
206	.driver = {
207		.name		= DRIVER_NAME,
208		.of_match_table	= meson_ir_match,
209	},
210};
211
212module_platform_driver(meson_ir_driver);
213
214MODULE_DESCRIPTION("Amlogic Meson IR remote receiver driver");
215MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
216MODULE_LICENSE("GPL v2");
217