xref: /openbmc/linux/drivers/media/rc/meson-ir.c (revision 9cfc5c90)
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 
58 struct meson_ir {
59 	void __iomem	*reg;
60 	struct rc_dev	*rc;
61 	int		irq;
62 	spinlock_t	lock;
63 };
64 
65 static 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 
76 static 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 
98 static 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;
174 out_unreg:
175 	rc_unregister_device(ir->rc);
176 	ir->rc = NULL;
177 out_free:
178 	rc_free_device(ir->rc);
179 
180 	return ret;
181 }
182 
183 static 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 
198 static const struct of_device_id meson_ir_match[] = {
199 	{ .compatible = "amlogic,meson6-ir" },
200 	{ },
201 };
202 
203 static 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 
212 module_platform_driver(meson_ir_driver);
213 
214 MODULE_DESCRIPTION("Amlogic Meson IR remote receiver driver");
215 MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
216 MODULE_LICENSE("GPL v2");
217