1 /*
2  * Copyright (C) 2017 Sanechips Technology Co., Ltd.
3  * Copyright 2017 Linaro Ltd.
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  */
9 
10 #include <linux/device.h>
11 #include <linux/err.h>
12 #include <linux/interrupt.h>
13 #include <linux/io.h>
14 #include <linux/module.h>
15 #include <linux/of_platform.h>
16 #include <linux/platform_device.h>
17 
18 #include <media/rc-core.h>
19 
20 #define DRIVER_NAME		"zx-irdec"
21 
22 #define ZX_IR_ENABLE		0x04
23 #define ZX_IREN			BIT(0)
24 #define ZX_IR_CTRL		0x08
25 #define ZX_DEGL_MASK		GENMASK(21, 20)
26 #define ZX_DEGL_VALUE(x)	(((x) << 20) & ZX_DEGL_MASK)
27 #define ZX_WDBEGIN_MASK		GENMASK(18, 8)
28 #define ZX_WDBEGIN_VALUE(x)	(((x) << 8) & ZX_WDBEGIN_MASK)
29 #define ZX_IR_INTEN		0x10
30 #define ZX_IR_INTSTCLR		0x14
31 #define ZX_IR_CODE		0x30
32 #define ZX_IR_CNUM		0x34
33 #define ZX_NECRPT		BIT(16)
34 
35 struct zx_irdec {
36 	void __iomem *base;
37 	struct rc_dev *rcd;
38 };
39 
zx_irdec_set_mask(struct zx_irdec * irdec,unsigned int reg,u32 mask,u32 value)40 static void zx_irdec_set_mask(struct zx_irdec *irdec, unsigned int reg,
41 			      u32 mask, u32 value)
42 {
43 	u32 data;
44 
45 	data = readl(irdec->base + reg);
46 	data &= ~mask;
47 	data |= value & mask;
48 	writel(data, irdec->base + reg);
49 }
50 
zx_irdec_irq(int irq,void * dev_id)51 static irqreturn_t zx_irdec_irq(int irq, void *dev_id)
52 {
53 	struct zx_irdec *irdec = dev_id;
54 	u8 address, not_address;
55 	u8 command, not_command;
56 	u32 rawcode, scancode;
57 	enum rc_proto rc_proto;
58 
59 	/* Clear interrupt */
60 	writel(1, irdec->base + ZX_IR_INTSTCLR);
61 
62 	/* Check repeat frame */
63 	if (readl(irdec->base + ZX_IR_CNUM) & ZX_NECRPT) {
64 		rc_repeat(irdec->rcd);
65 		goto done;
66 	}
67 
68 	rawcode = readl(irdec->base + ZX_IR_CODE);
69 	not_command = (rawcode >> 24) & 0xff;
70 	command = (rawcode >> 16) & 0xff;
71 	not_address = (rawcode >> 8) & 0xff;
72 	address = rawcode & 0xff;
73 
74 	scancode = ir_nec_bytes_to_scancode(address, not_address,
75 					    command, not_command,
76 					    &rc_proto);
77 	rc_keydown(irdec->rcd, rc_proto, scancode, 0);
78 
79 done:
80 	return IRQ_HANDLED;
81 }
82 
zx_irdec_probe(struct platform_device * pdev)83 static int zx_irdec_probe(struct platform_device *pdev)
84 {
85 	struct device *dev = &pdev->dev;
86 	struct zx_irdec *irdec;
87 	struct resource *res;
88 	struct rc_dev *rcd;
89 	int irq;
90 	int ret;
91 
92 	irdec = devm_kzalloc(dev, sizeof(*irdec), GFP_KERNEL);
93 	if (!irdec)
94 		return -ENOMEM;
95 
96 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
97 	irdec->base = devm_ioremap_resource(dev, res);
98 	if (IS_ERR(irdec->base))
99 		return PTR_ERR(irdec->base);
100 
101 	irq = platform_get_irq(pdev, 0);
102 	if (irq < 0)
103 		return irq;
104 
105 	rcd = devm_rc_allocate_device(dev, RC_DRIVER_SCANCODE);
106 	if (!rcd) {
107 		dev_err(dev, "failed to allocate rc device\n");
108 		return -ENOMEM;
109 	}
110 
111 	irdec->rcd = rcd;
112 
113 	rcd->priv = irdec;
114 	rcd->input_phys = DRIVER_NAME "/input0";
115 	rcd->input_id.bustype = BUS_HOST;
116 	rcd->map_name = RC_MAP_ZX_IRDEC;
117 	rcd->allowed_protocols = RC_PROTO_BIT_NEC | RC_PROTO_BIT_NECX |
118 							RC_PROTO_BIT_NEC32;
119 	rcd->driver_name = DRIVER_NAME;
120 	rcd->device_name = DRIVER_NAME;
121 
122 	platform_set_drvdata(pdev, irdec);
123 
124 	ret = devm_rc_register_device(dev, rcd);
125 	if (ret) {
126 		dev_err(dev, "failed to register rc device\n");
127 		return ret;
128 	}
129 
130 	ret = devm_request_irq(dev, irq, zx_irdec_irq, 0, NULL, irdec);
131 	if (ret) {
132 		dev_err(dev, "failed to request irq\n");
133 		return ret;
134 	}
135 
136 	/*
137 	 * Initialize deglitch level and watchdog counter beginner as
138 	 * recommended by vendor BSP code.
139 	 */
140 	zx_irdec_set_mask(irdec, ZX_IR_CTRL, ZX_DEGL_MASK, ZX_DEGL_VALUE(0));
141 	zx_irdec_set_mask(irdec, ZX_IR_CTRL, ZX_WDBEGIN_MASK,
142 			  ZX_WDBEGIN_VALUE(0x21c));
143 
144 	/* Enable interrupt */
145 	writel(1, irdec->base + ZX_IR_INTEN);
146 
147 	/* Enable the decoder */
148 	zx_irdec_set_mask(irdec, ZX_IR_ENABLE, ZX_IREN, ZX_IREN);
149 
150 	return 0;
151 }
152 
zx_irdec_remove(struct platform_device * pdev)153 static int zx_irdec_remove(struct platform_device *pdev)
154 {
155 	struct zx_irdec *irdec = platform_get_drvdata(pdev);
156 
157 	/* Disable the decoder */
158 	zx_irdec_set_mask(irdec, ZX_IR_ENABLE, ZX_IREN, 0);
159 
160 	/* Disable interrupt */
161 	writel(0, irdec->base + ZX_IR_INTEN);
162 
163 	return 0;
164 }
165 
166 static const struct of_device_id zx_irdec_match[] = {
167 	{ .compatible = "zte,zx296718-irdec" },
168 	{ },
169 };
170 MODULE_DEVICE_TABLE(of, zx_irdec_match);
171 
172 static struct platform_driver zx_irdec_driver = {
173 	.probe = zx_irdec_probe,
174 	.remove = zx_irdec_remove,
175 	.driver = {
176 		.name = DRIVER_NAME,
177 		.of_match_table	= zx_irdec_match,
178 	},
179 };
180 module_platform_driver(zx_irdec_driver);
181 
182 MODULE_DESCRIPTION("ZTE ZX IR remote control driver");
183 MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>");
184 MODULE_LICENSE("GPL v2");
185