1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Driver for Amlogic Meson IR remote receiver
4 *
5 * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
6 */
7
8#include <linux/device.h>
9#include <linux/err.h>
10#include <linux/interrupt.h>
11#include <linux/io.h>
12#include <linux/module.h>
13#include <linux/of_platform.h>
14#include <linux/platform_device.h>
15#include <linux/spinlock.h>
16#include <linux/bitfield.h>
17
18#include <media/rc-core.h>
19
20#define DRIVER_NAME		"meson-ir"
21
22/* valid on all Meson platforms */
23#define IR_DEC_LDR_ACTIVE	0x00
24#define IR_DEC_LDR_IDLE		0x04
25#define IR_DEC_LDR_REPEAT	0x08
26#define IR_DEC_BIT_0		0x0c
27#define IR_DEC_REG0		0x10
28#define IR_DEC_FRAME		0x14
29#define IR_DEC_STATUS		0x18
30#define IR_DEC_REG1		0x1c
31/* only available on Meson 8b and newer */
32#define IR_DEC_REG2		0x20
33
34#define REG0_RATE_MASK		GENMASK(11, 0)
35
36#define DECODE_MODE_NEC		0x0
37#define DECODE_MODE_RAW		0x2
38
39/* Meson 6b uses REG1 to configure the mode */
40#define REG1_MODE_MASK		GENMASK(8, 7)
41#define REG1_MODE_SHIFT		7
42
43/* Meson 8b / GXBB use REG2 to configure the mode */
44#define REG2_MODE_MASK		GENMASK(3, 0)
45#define REG2_MODE_SHIFT		0
46
47#define REG1_TIME_IV_MASK	GENMASK(28, 16)
48
49#define REG1_IRQSEL_MASK	GENMASK(3, 2)
50#define REG1_IRQSEL_NEC_MODE	0
51#define REG1_IRQSEL_RISE_FALL	1
52#define REG1_IRQSEL_FALL	2
53#define REG1_IRQSEL_RISE	3
54
55#define REG1_RESET		BIT(0)
56#define REG1_ENABLE		BIT(15)
57
58#define STATUS_IR_DEC_IN	BIT(8)
59
60#define MESON_TRATE		10	/* us */
61
62struct meson_ir {
63	void __iomem	*reg;
64	struct rc_dev	*rc;
65	spinlock_t	lock;
66};
67
68static void meson_ir_set_mask(struct meson_ir *ir, unsigned int reg,
69			      u32 mask, u32 value)
70{
71	u32 data;
72
73	data = readl(ir->reg + reg);
74	data &= ~mask;
75	data |= (value & mask);
76	writel(data, ir->reg + reg);
77}
78
79static irqreturn_t meson_ir_irq(int irqno, void *dev_id)
80{
81	struct meson_ir *ir = dev_id;
82	u32 duration, status;
83	struct ir_raw_event rawir = {};
84
85	spin_lock(&ir->lock);
86
87	duration = readl_relaxed(ir->reg + IR_DEC_REG1);
88	duration = FIELD_GET(REG1_TIME_IV_MASK, duration);
89	rawir.duration = duration * MESON_TRATE;
90
91	status = readl_relaxed(ir->reg + IR_DEC_STATUS);
92	rawir.pulse = !!(status & STATUS_IR_DEC_IN);
93
94	ir_raw_event_store_with_timeout(ir->rc, &rawir);
95
96	spin_unlock(&ir->lock);
97
98	return IRQ_HANDLED;
99}
100
101static int meson_ir_probe(struct platform_device *pdev)
102{
103	struct device *dev = &pdev->dev;
104	struct device_node *node = dev->of_node;
105	struct resource *res;
106	const char *map_name;
107	struct meson_ir *ir;
108	int irq, ret;
109
110	ir = devm_kzalloc(dev, sizeof(struct meson_ir), GFP_KERNEL);
111	if (!ir)
112		return -ENOMEM;
113
114	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
115	ir->reg = devm_ioremap_resource(dev, res);
116	if (IS_ERR(ir->reg))
117		return PTR_ERR(ir->reg);
118
119	irq = platform_get_irq(pdev, 0);
120	if (irq < 0)
121		return irq;
122
123	ir->rc = devm_rc_allocate_device(dev, RC_DRIVER_IR_RAW);
124	if (!ir->rc) {
125		dev_err(dev, "failed to allocate rc device\n");
126		return -ENOMEM;
127	}
128
129	ir->rc->priv = ir;
130	ir->rc->device_name = DRIVER_NAME;
131	ir->rc->input_phys = DRIVER_NAME "/input0";
132	ir->rc->input_id.bustype = BUS_HOST;
133	map_name = of_get_property(node, "linux,rc-map-name", NULL);
134	ir->rc->map_name = map_name ? map_name : RC_MAP_EMPTY;
135	ir->rc->allowed_protocols = RC_PROTO_BIT_ALL_IR_DECODER;
136	ir->rc->rx_resolution = MESON_TRATE;
137	ir->rc->min_timeout = 1;
138	ir->rc->timeout = IR_DEFAULT_TIMEOUT;
139	ir->rc->max_timeout = 10 * IR_DEFAULT_TIMEOUT;
140	ir->rc->driver_name = DRIVER_NAME;
141
142	spin_lock_init(&ir->lock);
143	platform_set_drvdata(pdev, ir);
144
145	ret = devm_rc_register_device(dev, ir->rc);
146	if (ret) {
147		dev_err(dev, "failed to register rc device\n");
148		return ret;
149	}
150
151	ret = devm_request_irq(dev, irq, meson_ir_irq, 0, NULL, ir);
152	if (ret) {
153		dev_err(dev, "failed to request irq\n");
154		return ret;
155	}
156
157	/* Reset the decoder */
158	meson_ir_set_mask(ir, IR_DEC_REG1, REG1_RESET, REG1_RESET);
159	meson_ir_set_mask(ir, IR_DEC_REG1, REG1_RESET, 0);
160
161	/* Set general operation mode (= raw/software decoding) */
162	if (of_device_is_compatible(node, "amlogic,meson6-ir"))
163		meson_ir_set_mask(ir, IR_DEC_REG1, REG1_MODE_MASK,
164				  FIELD_PREP(REG1_MODE_MASK, DECODE_MODE_RAW));
165	else
166		meson_ir_set_mask(ir, IR_DEC_REG2, REG2_MODE_MASK,
167				  FIELD_PREP(REG2_MODE_MASK, DECODE_MODE_RAW));
168
169	/* Set rate */
170	meson_ir_set_mask(ir, IR_DEC_REG0, REG0_RATE_MASK, MESON_TRATE - 1);
171	/* IRQ on rising and falling edges */
172	meson_ir_set_mask(ir, IR_DEC_REG1, REG1_IRQSEL_MASK,
173			  FIELD_PREP(REG1_IRQSEL_MASK, REG1_IRQSEL_RISE_FALL));
174	/* Enable the decoder */
175	meson_ir_set_mask(ir, IR_DEC_REG1, REG1_ENABLE, REG1_ENABLE);
176
177	dev_info(dev, "receiver initialized\n");
178
179	return 0;
180}
181
182static int meson_ir_remove(struct platform_device *pdev)
183{
184	struct meson_ir *ir = platform_get_drvdata(pdev);
185	unsigned long flags;
186
187	/* Disable the decoder */
188	spin_lock_irqsave(&ir->lock, flags);
189	meson_ir_set_mask(ir, IR_DEC_REG1, REG1_ENABLE, 0);
190	spin_unlock_irqrestore(&ir->lock, flags);
191
192	return 0;
193}
194
195static void meson_ir_shutdown(struct platform_device *pdev)
196{
197	struct device *dev = &pdev->dev;
198	struct device_node *node = dev->of_node;
199	struct meson_ir *ir = platform_get_drvdata(pdev);
200	unsigned long flags;
201
202	spin_lock_irqsave(&ir->lock, flags);
203
204	/*
205	 * Set operation mode to NEC/hardware decoding to give
206	 * bootloader a chance to power the system back on
207	 */
208	if (of_device_is_compatible(node, "amlogic,meson6-ir"))
209		meson_ir_set_mask(ir, IR_DEC_REG1, REG1_MODE_MASK,
210				  DECODE_MODE_NEC << REG1_MODE_SHIFT);
211	else
212		meson_ir_set_mask(ir, IR_DEC_REG2, REG2_MODE_MASK,
213				  DECODE_MODE_NEC << REG2_MODE_SHIFT);
214
215	/* Set rate to default value */
216	meson_ir_set_mask(ir, IR_DEC_REG0, REG0_RATE_MASK, 0x13);
217
218	spin_unlock_irqrestore(&ir->lock, flags);
219}
220
221static const struct of_device_id meson_ir_match[] = {
222	{ .compatible = "amlogic,meson6-ir" },
223	{ .compatible = "amlogic,meson8b-ir" },
224	{ .compatible = "amlogic,meson-gxbb-ir" },
225	{ },
226};
227MODULE_DEVICE_TABLE(of, meson_ir_match);
228
229static struct platform_driver meson_ir_driver = {
230	.probe		= meson_ir_probe,
231	.remove		= meson_ir_remove,
232	.shutdown	= meson_ir_shutdown,
233	.driver = {
234		.name		= DRIVER_NAME,
235		.of_match_table	= meson_ir_match,
236	},
237};
238
239module_platform_driver(meson_ir_driver);
240
241MODULE_DESCRIPTION("Amlogic Meson IR remote receiver driver");
242MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
243MODULE_LICENSE("GPL v2");
244