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(*kmi), GFP_KERNEL);
118 io = kzalloc(sizeof(*io), 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 .pm = pm_sleep_ptr(&amba_kmi_dev_pm_ops),
199 },
200 .id_table = amba_kmi_idtable,
201 .probe = amba_kmi_probe,
202 .remove = amba_kmi_remove,
203 };
204
205 module_amba_driver(ambakmi_driver);
206
207 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
208 MODULE_DESCRIPTION("AMBA KMI controller driver");
209 MODULE_LICENSE("GPL");
210