1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4 *
5 * Driver is originally developed by Pavel Sokolov <psokolov@synopsys.com>
6 */
7
8 #include <linux/err.h>
9 #include <linux/module.h>
10 #include <linux/interrupt.h>
11 #include <linux/input.h>
12 #include <linux/serio.h>
13 #include <linux/platform_device.h>
14 #include <linux/of.h>
15 #include <linux/io.h>
16 #include <linux/kernel.h>
17 #include <linux/slab.h>
18
19 #define ARC_PS2_PORTS 2
20
21 #define ARC_ARC_PS2_ID 0x0001f609
22
23 #define STAT_TIMEOUT 128
24
25 #define PS2_STAT_RX_FRM_ERR (1)
26 #define PS2_STAT_RX_BUF_OVER (1 << 1)
27 #define PS2_STAT_RX_INT_EN (1 << 2)
28 #define PS2_STAT_RX_VAL (1 << 3)
29 #define PS2_STAT_TX_ISNOT_FUL (1 << 4)
30 #define PS2_STAT_TX_INT_EN (1 << 5)
31
32 struct arc_ps2_port {
33 void __iomem *data_addr;
34 void __iomem *status_addr;
35 struct serio *io;
36 };
37
38 struct arc_ps2_data {
39 struct arc_ps2_port port[ARC_PS2_PORTS];
40 void __iomem *addr;
41 unsigned int frame_error;
42 unsigned int buf_overflow;
43 unsigned int total_int;
44 };
45
arc_ps2_check_rx(struct arc_ps2_data * arc_ps2,struct arc_ps2_port * port)46 static void arc_ps2_check_rx(struct arc_ps2_data *arc_ps2,
47 struct arc_ps2_port *port)
48 {
49 unsigned int timeout = 1000;
50 unsigned int flag, status;
51 unsigned char data;
52
53 do {
54 status = ioread32(port->status_addr);
55 if (!(status & PS2_STAT_RX_VAL))
56 return;
57
58 data = ioread32(port->data_addr) & 0xff;
59
60 flag = 0;
61 arc_ps2->total_int++;
62 if (status & PS2_STAT_RX_FRM_ERR) {
63 arc_ps2->frame_error++;
64 flag |= SERIO_PARITY;
65 } else if (status & PS2_STAT_RX_BUF_OVER) {
66 arc_ps2->buf_overflow++;
67 flag |= SERIO_FRAME;
68 }
69
70 serio_interrupt(port->io, data, flag);
71 } while (--timeout);
72
73 dev_err(&port->io->dev, "PS/2 hardware stuck\n");
74 }
75
arc_ps2_interrupt(int irq,void * dev)76 static irqreturn_t arc_ps2_interrupt(int irq, void *dev)
77 {
78 struct arc_ps2_data *arc_ps2 = dev;
79 int i;
80
81 for (i = 0; i < ARC_PS2_PORTS; i++)
82 arc_ps2_check_rx(arc_ps2, &arc_ps2->port[i]);
83
84 return IRQ_HANDLED;
85 }
86
arc_ps2_write(struct serio * io,unsigned char val)87 static int arc_ps2_write(struct serio *io, unsigned char val)
88 {
89 unsigned status;
90 struct arc_ps2_port *port = io->port_data;
91 int timeout = STAT_TIMEOUT;
92
93 do {
94 status = ioread32(port->status_addr);
95 cpu_relax();
96
97 if (status & PS2_STAT_TX_ISNOT_FUL) {
98 iowrite32(val & 0xff, port->data_addr);
99 return 0;
100 }
101
102 } while (--timeout);
103
104 dev_err(&io->dev, "write timeout\n");
105 return -ETIMEDOUT;
106 }
107
arc_ps2_open(struct serio * io)108 static int arc_ps2_open(struct serio *io)
109 {
110 struct arc_ps2_port *port = io->port_data;
111
112 iowrite32(PS2_STAT_RX_INT_EN, port->status_addr);
113
114 return 0;
115 }
116
arc_ps2_close(struct serio * io)117 static void arc_ps2_close(struct serio *io)
118 {
119 struct arc_ps2_port *port = io->port_data;
120
121 iowrite32(ioread32(port->status_addr) & ~PS2_STAT_RX_INT_EN,
122 port->status_addr);
123 }
124
arc_ps2_calc_addr(struct arc_ps2_data * arc_ps2,int index,bool status)125 static void __iomem *arc_ps2_calc_addr(struct arc_ps2_data *arc_ps2,
126 int index, bool status)
127 {
128 void __iomem *addr;
129
130 addr = arc_ps2->addr + 4 + 4 * index;
131 if (status)
132 addr += ARC_PS2_PORTS * 4;
133
134 return addr;
135 }
136
arc_ps2_inhibit_ports(struct arc_ps2_data * arc_ps2)137 static void arc_ps2_inhibit_ports(struct arc_ps2_data *arc_ps2)
138 {
139 void __iomem *addr;
140 u32 val;
141 int i;
142
143 for (i = 0; i < ARC_PS2_PORTS; i++) {
144 addr = arc_ps2_calc_addr(arc_ps2, i, true);
145 val = ioread32(addr);
146 val &= ~(PS2_STAT_RX_INT_EN | PS2_STAT_TX_INT_EN);
147 iowrite32(val, addr);
148 }
149 }
150
arc_ps2_create_port(struct platform_device * pdev,struct arc_ps2_data * arc_ps2,int index)151 static int arc_ps2_create_port(struct platform_device *pdev,
152 struct arc_ps2_data *arc_ps2,
153 int index)
154 {
155 struct arc_ps2_port *port = &arc_ps2->port[index];
156 struct serio *io;
157
158 io = kzalloc(sizeof(struct serio), GFP_KERNEL);
159 if (!io)
160 return -ENOMEM;
161
162 io->id.type = SERIO_8042;
163 io->write = arc_ps2_write;
164 io->open = arc_ps2_open;
165 io->close = arc_ps2_close;
166 snprintf(io->name, sizeof(io->name), "ARC PS/2 port%d", index);
167 snprintf(io->phys, sizeof(io->phys), "arc/serio%d", index);
168 io->port_data = port;
169
170 port->io = io;
171
172 port->data_addr = arc_ps2_calc_addr(arc_ps2, index, false);
173 port->status_addr = arc_ps2_calc_addr(arc_ps2, index, true);
174
175 dev_dbg(&pdev->dev, "port%d is allocated (data = 0x%p, status = 0x%p)\n",
176 index, port->data_addr, port->status_addr);
177
178 serio_register_port(port->io);
179 return 0;
180 }
181
arc_ps2_probe(struct platform_device * pdev)182 static int arc_ps2_probe(struct platform_device *pdev)
183 {
184 struct arc_ps2_data *arc_ps2;
185 int irq;
186 int error, id, i;
187
188 irq = platform_get_irq_byname(pdev, "arc_ps2_irq");
189 if (irq < 0)
190 return -EINVAL;
191
192 arc_ps2 = devm_kzalloc(&pdev->dev, sizeof(struct arc_ps2_data),
193 GFP_KERNEL);
194 if (!arc_ps2) {
195 dev_err(&pdev->dev, "out of memory\n");
196 return -ENOMEM;
197 }
198
199 arc_ps2->addr = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
200 if (IS_ERR(arc_ps2->addr))
201 return PTR_ERR(arc_ps2->addr);
202
203 dev_info(&pdev->dev, "irq = %d, address = 0x%p, ports = %i\n",
204 irq, arc_ps2->addr, ARC_PS2_PORTS);
205
206 id = ioread32(arc_ps2->addr);
207 if (id != ARC_ARC_PS2_ID) {
208 dev_err(&pdev->dev, "device id does not match\n");
209 return -ENXIO;
210 }
211
212 arc_ps2_inhibit_ports(arc_ps2);
213
214 error = devm_request_irq(&pdev->dev, irq, arc_ps2_interrupt,
215 0, "arc_ps2", arc_ps2);
216 if (error) {
217 dev_err(&pdev->dev, "Could not allocate IRQ\n");
218 return error;
219 }
220
221 for (i = 0; i < ARC_PS2_PORTS; i++) {
222 error = arc_ps2_create_port(pdev, arc_ps2, i);
223 if (error) {
224 while (--i >= 0)
225 serio_unregister_port(arc_ps2->port[i].io);
226 return error;
227 }
228 }
229
230 platform_set_drvdata(pdev, arc_ps2);
231
232 return 0;
233 }
234
arc_ps2_remove(struct platform_device * pdev)235 static int arc_ps2_remove(struct platform_device *pdev)
236 {
237 struct arc_ps2_data *arc_ps2 = platform_get_drvdata(pdev);
238 int i;
239
240 for (i = 0; i < ARC_PS2_PORTS; i++)
241 serio_unregister_port(arc_ps2->port[i].io);
242
243 dev_dbg(&pdev->dev, "interrupt count = %i\n", arc_ps2->total_int);
244 dev_dbg(&pdev->dev, "frame error count = %i\n", arc_ps2->frame_error);
245 dev_dbg(&pdev->dev, "buffer overflow count = %i\n",
246 arc_ps2->buf_overflow);
247
248 return 0;
249 }
250
251 #ifdef CONFIG_OF
252 static const struct of_device_id arc_ps2_match[] = {
253 { .compatible = "snps,arc_ps2" },
254 { },
255 };
256 MODULE_DEVICE_TABLE(of, arc_ps2_match);
257 #endif
258
259 static struct platform_driver arc_ps2_driver = {
260 .driver = {
261 .name = "arc_ps2",
262 .of_match_table = of_match_ptr(arc_ps2_match),
263 },
264 .probe = arc_ps2_probe,
265 .remove = arc_ps2_remove,
266 };
267
268 module_platform_driver(arc_ps2_driver);
269
270 MODULE_LICENSE("GPL");
271 MODULE_AUTHOR("Pavel Sokolov <psokolov@synopsys.com>");
272 MODULE_DESCRIPTION("ARC PS/2 Driver");
273
