1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  *  linux/drivers/input/serio/ambakmi.c
4  *
5  *  Copyright (C) 2000-2003 Deep Blue Solutions Ltd.
6  *  Copyright (C) 2002 Russell King.
7  */
8 #include <linux/module.h>
9 #include <linux/serio.h>
10 #include <linux/errno.h>
11 #include <linux/interrupt.h>
12 #include <linux/ioport.h>
13 #include <linux/device.h>
14 #include <linux/delay.h>
15 #include <linux/slab.h>
16 #include <linux/err.h>
17 #include <linux/amba/bus.h>
18 #include <linux/amba/kmi.h>
19 #include <linux/clk.h>
20 
21 #include <asm/io.h>
22 #include <asm/irq.h>
23 
24 #define KMI_BASE	(kmi->base)
25 
26 struct amba_kmi_port {
27 	struct serio		*io;
28 	struct clk		*clk;
29 	void __iomem		*base;
30 	unsigned int		irq;
31 	unsigned int		divisor;
32 	unsigned int		open;
33 };
34 
amba_kmi_int(int irq,void * dev_id)35 static irqreturn_t amba_kmi_int(int irq, void *dev_id)
36 {
37 	struct amba_kmi_port *kmi = dev_id;
38 	unsigned int status = readb(KMIIR);
39 	int handled = IRQ_NONE;
40 
41 	while (status & KMIIR_RXINTR) {
42 		serio_interrupt(kmi->io, readb(KMIDATA), 0);
43 		status = readb(KMIIR);
44 		handled = IRQ_HANDLED;
45 	}
46 
47 	return handled;
48 }
49 
amba_kmi_write(struct serio * io,unsigned char val)50 static int amba_kmi_write(struct serio *io, unsigned char val)
51 {
52 	struct amba_kmi_port *kmi = io->port_data;
53 	unsigned int timeleft = 10000; /* timeout in 100ms */
54 
55 	while ((readb(KMISTAT) & KMISTAT_TXEMPTY) == 0 && --timeleft)
56 		udelay(10);
57 
58 	if (timeleft)
59 		writeb(val, KMIDATA);
60 
61 	return timeleft ? 0 : SERIO_TIMEOUT;
62 }
63 
amba_kmi_open(struct serio * io)64 static int amba_kmi_open(struct serio *io)
65 {
66 	struct amba_kmi_port *kmi = io->port_data;
67 	unsigned int divisor;
68 	int ret;
69 
70 	ret = clk_prepare_enable(kmi->clk);
71 	if (ret)
72 		goto out;
73 
74 	divisor = clk_get_rate(kmi->clk) / 8000000 - 1;
75 	writeb(divisor, KMICLKDIV);
76 	writeb(KMICR_EN, KMICR);
77 
78 	ret = request_irq(kmi->irq, amba_kmi_int, IRQF_SHARED, "kmi-pl050",
79 			  kmi);
80 	if (ret) {
81 		printk(KERN_ERR "kmi: failed to claim IRQ%d\n", kmi->irq);
82 		writeb(0, KMICR);
83 		goto clk_disable;
84 	}
85 
86 	writeb(KMICR_EN | KMICR_RXINTREN, KMICR);
87 
88 	return 0;
89 
90  clk_disable:
91 	clk_disable_unprepare(kmi->clk);
92  out:
93 	return ret;
94 }
95 
amba_kmi_close(struct serio * io)96 static void amba_kmi_close(struct serio *io)
97 {
98 	struct amba_kmi_port *kmi = io->port_data;
99 
100 	writeb(0, KMICR);
101 
102 	free_irq(kmi->irq, kmi);
103 	clk_disable_unprepare(kmi->clk);
104 }
105 
amba_kmi_probe(struct amba_device * dev,const struct amba_id * id)106 static int amba_kmi_probe(struct amba_device *dev,
107 	const struct amba_id *id)
108 {
109 	struct amba_kmi_port *kmi;
110 	struct serio *io;
111 	int ret;
112 
113 	ret = amba_request_regions(dev, NULL);
114 	if (ret)
115 		return ret;
116 
117 	kmi = kzalloc(sizeof(struct amba_kmi_port), GFP_KERNEL);
118 	io = kzalloc(sizeof(struct serio), GFP_KERNEL);
119 	if (!kmi || !io) {
120 		ret = -ENOMEM;
121 		goto out;
122 	}
123 
124 
125 	io->id.type	= SERIO_8042;
126 	io->write	= amba_kmi_write;
127 	io->open	= amba_kmi_open;
128 	io->close	= amba_kmi_close;
129 	strscpy(io->name, dev_name(&dev->dev), sizeof(io->name));
130 	strscpy(io->phys, dev_name(&dev->dev), sizeof(io->phys));
131 	io->port_data	= kmi;
132 	io->dev.parent	= &dev->dev;
133 
134 	kmi->io		= io;
135 	kmi->base	= ioremap(dev->res.start, resource_size(&dev->res));
136 	if (!kmi->base) {
137 		ret = -ENOMEM;
138 		goto out;
139 	}
140 
141 	kmi->clk = clk_get(&dev->dev, "KMIREFCLK");
142 	if (IS_ERR(kmi->clk)) {
143 		ret = PTR_ERR(kmi->clk);
144 		goto unmap;
145 	}
146 
147 	kmi->irq = dev->irq[0];
148 	amba_set_drvdata(dev, kmi);
149 
150 	serio_register_port(kmi->io);
151 	return 0;
152 
153  unmap:
154 	iounmap(kmi->base);
155  out:
156 	kfree(kmi);
157 	kfree(io);
158 	amba_release_regions(dev);
159 	return ret;
160 }
161 
amba_kmi_remove(struct amba_device * dev)162 static void amba_kmi_remove(struct amba_device *dev)
163 {
164 	struct amba_kmi_port *kmi = amba_get_drvdata(dev);
165 
166 	serio_unregister_port(kmi->io);
167 	clk_put(kmi->clk);
168 	iounmap(kmi->base);
169 	kfree(kmi);
170 	amba_release_regions(dev);
171 }
172 
amba_kmi_resume(struct device * dev)173 static int amba_kmi_resume(struct device *dev)
174 {
175 	struct amba_kmi_port *kmi = dev_get_drvdata(dev);
176 
177 	/* kick the serio layer to rescan this port */
178 	serio_reconnect(kmi->io);
179 
180 	return 0;
181 }
182 
183 static DEFINE_SIMPLE_DEV_PM_OPS(amba_kmi_dev_pm_ops, NULL, amba_kmi_resume);
184 
185 static const struct amba_id amba_kmi_idtable[] = {
186 	{
187 		.id	= 0x00041050,
188 		.mask	= 0x000fffff,
189 	},
190 	{ 0, 0 }
191 };
192 
193 MODULE_DEVICE_TABLE(amba, amba_kmi_idtable);
194 
195 static struct amba_driver ambakmi_driver = {
196 	.drv		= {
197 		.name	= "kmi-pl050",
198 		.owner	= THIS_MODULE,
199 		.pm	= pm_sleep_ptr(&amba_kmi_dev_pm_ops),
200 	},
201 	.id_table	= amba_kmi_idtable,
202 	.probe		= amba_kmi_probe,
203 	.remove		= amba_kmi_remove,
204 };
205 
206 module_amba_driver(ambakmi_driver);
207 
208 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
209 MODULE_DESCRIPTION("AMBA KMI controller driver");
210 MODULE_LICENSE("GPL");
211