1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * ImgTec IR Decoder found in PowerDown Controller.
4  *
5  * Copyright 2010-2014 Imagination Technologies Ltd.
6  *
7  * This contains core img-ir code for setting up the driver. The two interfaces
8  * (raw and hardware decode) are handled separately.
9  */
10 
11 #include <linux/clk.h>
12 #include <linux/init.h>
13 #include <linux/interrupt.h>
14 #include <linux/io.h>
15 #include <linux/module.h>
16 #include <linux/platform_device.h>
17 #include <linux/slab.h>
18 #include <linux/spinlock.h>
19 #include "img-ir.h"
20 
21 static irqreturn_t img_ir_isr(int irq, void *dev_id)
22 {
23 	struct img_ir_priv *priv = dev_id;
24 	u32 irq_status;
25 
26 	spin_lock(&priv->lock);
27 	/* we have to clear irqs before reading */
28 	irq_status = img_ir_read(priv, IMG_IR_IRQ_STATUS);
29 	img_ir_write(priv, IMG_IR_IRQ_CLEAR, irq_status);
30 
31 	/* don't handle valid data irqs if we're only interested in matches */
32 	irq_status &= img_ir_read(priv, IMG_IR_IRQ_ENABLE);
33 
34 	/* hand off edge interrupts to raw decode handler */
35 	if (irq_status & IMG_IR_IRQ_EDGE && img_ir_raw_enabled(&priv->raw))
36 		img_ir_isr_raw(priv, irq_status);
37 
38 	/* hand off hardware match interrupts to hardware decode handler */
39 	if (irq_status & (IMG_IR_IRQ_DATA_MATCH |
40 			  IMG_IR_IRQ_DATA_VALID |
41 			  IMG_IR_IRQ_DATA2_VALID) &&
42 	    img_ir_hw_enabled(&priv->hw))
43 		img_ir_isr_hw(priv, irq_status);
44 
45 	spin_unlock(&priv->lock);
46 	return IRQ_HANDLED;
47 }
48 
49 static void img_ir_setup(struct img_ir_priv *priv)
50 {
51 	/* start off with interrupts disabled */
52 	img_ir_write(priv, IMG_IR_IRQ_ENABLE, 0);
53 
54 	img_ir_setup_raw(priv);
55 	img_ir_setup_hw(priv);
56 
57 	if (!IS_ERR(priv->clk))
58 		clk_prepare_enable(priv->clk);
59 }
60 
61 static void img_ir_ident(struct img_ir_priv *priv)
62 {
63 	u32 core_rev = img_ir_read(priv, IMG_IR_CORE_REV);
64 
65 	dev_info(priv->dev,
66 		 "IMG IR Decoder (%d.%d.%d.%d) probed successfully\n",
67 		 (core_rev & IMG_IR_DESIGNER) >> IMG_IR_DESIGNER_SHIFT,
68 		 (core_rev & IMG_IR_MAJOR_REV) >> IMG_IR_MAJOR_REV_SHIFT,
69 		 (core_rev & IMG_IR_MINOR_REV) >> IMG_IR_MINOR_REV_SHIFT,
70 		 (core_rev & IMG_IR_MAINT_REV) >> IMG_IR_MAINT_REV_SHIFT);
71 	dev_info(priv->dev, "Modes:%s%s\n",
72 		 img_ir_hw_enabled(&priv->hw) ? " hardware" : "",
73 		 img_ir_raw_enabled(&priv->raw) ? " raw" : "");
74 }
75 
76 static int img_ir_probe(struct platform_device *pdev)
77 {
78 	struct img_ir_priv *priv;
79 	struct resource *res_regs;
80 	int irq, error, error2;
81 
82 	/* Get resources from platform device */
83 	irq = platform_get_irq(pdev, 0);
84 	if (irq < 0) {
85 		dev_err(&pdev->dev, "cannot find IRQ resource\n");
86 		return irq;
87 	}
88 
89 	/* Private driver data */
90 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
91 	if (!priv)
92 		return -ENOMEM;
93 
94 	platform_set_drvdata(pdev, priv);
95 	priv->dev = &pdev->dev;
96 	spin_lock_init(&priv->lock);
97 
98 	/* Ioremap the registers */
99 	res_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
100 	priv->reg_base = devm_ioremap_resource(&pdev->dev, res_regs);
101 	if (IS_ERR(priv->reg_base))
102 		return PTR_ERR(priv->reg_base);
103 
104 	/* Get core clock */
105 	priv->clk = devm_clk_get(&pdev->dev, "core");
106 	if (IS_ERR(priv->clk))
107 		dev_warn(&pdev->dev, "cannot get core clock resource\n");
108 
109 	/* Get sys clock */
110 	priv->sys_clk = devm_clk_get(&pdev->dev, "sys");
111 	if (IS_ERR(priv->sys_clk))
112 		dev_warn(&pdev->dev, "cannot get sys clock resource\n");
113 	/*
114 	 * Enabling the system clock before the register interface is
115 	 * accessed. ISR shouldn't get called with Sys Clock disabled,
116 	 * hence exiting probe with an error.
117 	 */
118 	if (!IS_ERR(priv->sys_clk)) {
119 		error = clk_prepare_enable(priv->sys_clk);
120 		if (error) {
121 			dev_err(&pdev->dev, "cannot enable sys clock\n");
122 			return error;
123 		}
124 	}
125 
126 	/* Set up raw & hw decoder */
127 	error = img_ir_probe_raw(priv);
128 	error2 = img_ir_probe_hw(priv);
129 	if (error && error2) {
130 		if (error == -ENODEV)
131 			error = error2;
132 		goto err_probe;
133 	}
134 
135 	/* Get the IRQ */
136 	priv->irq = irq;
137 	error = request_irq(priv->irq, img_ir_isr, 0, "img-ir", priv);
138 	if (error) {
139 		dev_err(&pdev->dev, "cannot register IRQ %u\n",
140 			priv->irq);
141 		error = -EIO;
142 		goto err_irq;
143 	}
144 
145 	img_ir_ident(priv);
146 	img_ir_setup(priv);
147 
148 	return 0;
149 
150 err_irq:
151 	img_ir_remove_hw(priv);
152 	img_ir_remove_raw(priv);
153 err_probe:
154 	if (!IS_ERR(priv->sys_clk))
155 		clk_disable_unprepare(priv->sys_clk);
156 	return error;
157 }
158 
159 static int img_ir_remove(struct platform_device *pdev)
160 {
161 	struct img_ir_priv *priv = platform_get_drvdata(pdev);
162 
163 	free_irq(priv->irq, priv);
164 	img_ir_remove_hw(priv);
165 	img_ir_remove_raw(priv);
166 
167 	if (!IS_ERR(priv->clk))
168 		clk_disable_unprepare(priv->clk);
169 	if (!IS_ERR(priv->sys_clk))
170 		clk_disable_unprepare(priv->sys_clk);
171 	return 0;
172 }
173 
174 static SIMPLE_DEV_PM_OPS(img_ir_pmops, img_ir_suspend, img_ir_resume);
175 
176 static const struct of_device_id img_ir_match[] = {
177 	{ .compatible = "img,ir-rev1" },
178 	{}
179 };
180 MODULE_DEVICE_TABLE(of, img_ir_match);
181 
182 static struct platform_driver img_ir_driver = {
183 	.driver = {
184 		.name = "img-ir",
185 		.of_match_table	= img_ir_match,
186 		.pm = &img_ir_pmops,
187 	},
188 	.probe = img_ir_probe,
189 	.remove = img_ir_remove,
190 };
191 
192 module_platform_driver(img_ir_driver);
193 
194 MODULE_AUTHOR("Imagination Technologies Ltd.");
195 MODULE_DESCRIPTION("ImgTec IR");
196 MODULE_LICENSE("GPL");
197