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1/*
2 * OLPC serio driver for multiplexed input from Marvell MMP security processor
3 *
4 * Copyright (C) 2011-2013 One Laptop Per Child
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 */
16
17#include <linux/module.h>
18#include <linux/interrupt.h>
19#include <linux/serio.h>
20#include <linux/err.h>
21#include <linux/platform_device.h>
22#include <linux/io.h>
23#include <linux/of.h>
24#include <linux/slab.h>
25#include <linux/delay.h>
26
27/*
28 * The OLPC XO-1.75 and XO-4 laptops do not have a hardware PS/2 controller.
29 * Instead, the OLPC firmware runs a bit-banging PS/2 implementation on an
30 * otherwise-unused slow processor which is included in the Marvell MMP2/MMP3
31 * SoC, known as the "Security Processor" (SP) or "Wireless Trusted Module"
32 * (WTM). This firmware then reports its results via the WTM registers,
33 * which we read from the Application Processor (AP, i.e. main CPU) in this
34 * driver.
35 *
36 * On the hardware side we have a PS/2 mouse and an AT keyboard, the data
37 * is multiplexed through this system. We create a serio port for each one,
38 * and demultiplex the data accordingly.
39 */
40
41/* WTM register offsets */
42#define SECURE_PROCESSOR_COMMAND 0x40
43#define COMMAND_RETURN_STATUS 0x80
44#define COMMAND_FIFO_STATUS 0xc4
45#define PJ_RST_INTERRUPT 0xc8
46#define PJ_INTERRUPT_MASK 0xcc
47
48/*
49 * The upper byte of SECURE_PROCESSOR_COMMAND and COMMAND_RETURN_STATUS is
50 * used to identify which port (device) is being talked to. The lower byte
51 * is the data being sent/received.
52 */
53#define PORT_MASK 0xff00
54#define DATA_MASK 0x00ff
55#define PORT_SHIFT 8
56#define KEYBOARD_PORT 0
57#define TOUCHPAD_PORT 1
58
59/* COMMAND_FIFO_STATUS */
60#define CMD_CNTR_MASK 0x7 /* Number of pending/unprocessed commands */
61#define MAX_PENDING_CMDS 4 /* from device specs */
62
63/* PJ_RST_INTERRUPT */
64#define SP_COMMAND_COMPLETE_RESET 0x1
65
66/* PJ_INTERRUPT_MASK */
67#define INT_0 (1 << 0)
68
69/* COMMAND_FIFO_STATUS */
70#define CMD_STS_MASK 0x100
71
72struct olpc_apsp {
73 struct device *dev;
74 struct serio *kbio;
75 struct serio *padio;
76 void __iomem *base;
77 int open_count;
78 int irq;
79};
80
81static int olpc_apsp_write(struct serio *port, unsigned char val)
82{
83 struct olpc_apsp *priv = port->port_data;
84 unsigned int i;
85 u32 which = 0;
86
87 if (port == priv->padio)
88 which = TOUCHPAD_PORT << PORT_SHIFT;
89 else
90 which = KEYBOARD_PORT << PORT_SHIFT;
91
92 dev_dbg(priv->dev, "olpc_apsp_write which=%x val=%x\n", which, val);
93 for (i = 0; i < 50; i++) {
94 u32 sts = readl(priv->base + COMMAND_FIFO_STATUS);
95 if ((sts & CMD_CNTR_MASK) < MAX_PENDING_CMDS) {
96 writel(which | val,
97 priv->base + SECURE_PROCESSOR_COMMAND);
98 return 0;
99 }
100 /* SP busy. This has not been seen in practice. */
101 mdelay(1);
102 }
103
104 dev_dbg(priv->dev, "olpc_apsp_write timeout, status=%x\n",
105 readl(priv->base + COMMAND_FIFO_STATUS));
106
107 return -ETIMEDOUT;
108}
109
110static irqreturn_t olpc_apsp_rx(int irq, void *dev_id)
111{
112 struct olpc_apsp *priv = dev_id;
113 unsigned int w, tmp;
114 struct serio *serio;
115
116 /*
117 * Write 1 to PJ_RST_INTERRUPT to acknowledge and clear the interrupt
118 * Write 0xff00 to SECURE_PROCESSOR_COMMAND.
119 */
120 tmp = readl(priv->base + PJ_RST_INTERRUPT);
121 if (!(tmp & SP_COMMAND_COMPLETE_RESET)) {
122 dev_warn(priv->dev, "spurious interrupt?\n");
123 return IRQ_NONE;
124 }
125
126 w = readl(priv->base + COMMAND_RETURN_STATUS);
127 dev_dbg(priv->dev, "olpc_apsp_rx %x\n", w);
128
129 if (w >> PORT_SHIFT == KEYBOARD_PORT)
130 serio = priv->kbio;
131 else
132 serio = priv->padio;
133
134 serio_interrupt(serio, w & DATA_MASK, 0);
135
136 /* Ack and clear interrupt */
137 writel(tmp | SP_COMMAND_COMPLETE_RESET, priv->base + PJ_RST_INTERRUPT);
138 writel(PORT_MASK, priv->base + SECURE_PROCESSOR_COMMAND);
139
140 pm_wakeup_event(priv->dev, 1000);
141 return IRQ_HANDLED;
142}
143
144static int olpc_apsp_open(struct serio *port)
145{
146 struct olpc_apsp *priv = port->port_data;
147 unsigned int tmp;
148
149 if (priv->open_count++ == 0) {
150 /* Enable interrupt 0 by clearing its bit */
151 tmp = readl(priv->base + PJ_INTERRUPT_MASK);
152 writel(tmp & ~INT_0, priv->base + PJ_INTERRUPT_MASK);
153 }
154
155 return 0;
156}
157
158static void olpc_apsp_close(struct serio *port)
159{
160 struct olpc_apsp *priv = port->port_data;
161 unsigned int tmp;
162
163 if (--priv->open_count == 0) {
164 /* Disable interrupt 0 */
165 tmp = readl(priv->base + PJ_INTERRUPT_MASK);
166 writel(tmp | INT_0, priv->base + PJ_INTERRUPT_MASK);
167 }
168}
169
170static int olpc_apsp_probe(struct platform_device *pdev)
171{
172 struct serio *kb_serio, *pad_serio;
173 struct olpc_apsp *priv;
174 struct resource *res;
175 struct device_node *np;
176 unsigned long l;
177 int error;
178
179 priv = devm_kzalloc(&pdev->dev, sizeof(struct olpc_apsp), GFP_KERNEL);
180 if (!priv)
181 return -ENOMEM;
182
183 np = pdev->dev.of_node;
184 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
185 priv->base = devm_ioremap_resource(&pdev->dev, res);
186 if (IS_ERR(priv->base)) {
187 dev_err(&pdev->dev, "Failed to map WTM registers\n");
188 return PTR_ERR(priv->base);
189 }
190
191 priv->irq = platform_get_irq(pdev, 0);
192 if (priv->irq < 0)
193 return priv->irq;
194
195 l = readl(priv->base + COMMAND_FIFO_STATUS);
196 if (!(l & CMD_STS_MASK)) {
197 dev_err(&pdev->dev, "SP cannot accept commands.\n");
198 return -EIO;
199 }
200
201 /* KEYBOARD */
202 kb_serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
203 if (!kb_serio)
204 return -ENOMEM;
205 kb_serio->id.type = SERIO_8042_XL;
206 kb_serio->write = olpc_apsp_write;
207 kb_serio->open = olpc_apsp_open;
208 kb_serio->close = olpc_apsp_close;
209 kb_serio->port_data = priv;
210 kb_serio->dev.parent = &pdev->dev;
211 strlcpy(kb_serio->name, "sp keyboard", sizeof(kb_serio->name));
212 strlcpy(kb_serio->phys, "sp/serio0", sizeof(kb_serio->phys));
213 priv->kbio = kb_serio;
214 serio_register_port(kb_serio);
215
216 /* TOUCHPAD */
217 pad_serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
218 if (!pad_serio) {
219 error = -ENOMEM;
220 goto err_pad;
221 }
222 pad_serio->id.type = SERIO_8042;
223 pad_serio->write = olpc_apsp_write;
224 pad_serio->open = olpc_apsp_open;
225 pad_serio->close = olpc_apsp_close;
226 pad_serio->port_data = priv;
227 pad_serio->dev.parent = &pdev->dev;
228 strlcpy(pad_serio->name, "sp touchpad", sizeof(pad_serio->name));
229 strlcpy(pad_serio->phys, "sp/serio1", sizeof(pad_serio->phys));
230 priv->padio = pad_serio;
231 serio_register_port(pad_serio);
232
233 error = request_irq(priv->irq, olpc_apsp_rx, 0, "olpc-apsp", priv);
234 if (error) {
235 dev_err(&pdev->dev, "Failed to request IRQ\n");
236 goto err_irq;
237 }
238
239 priv->dev = &pdev->dev;
240 device_init_wakeup(priv->dev, 1);
241 platform_set_drvdata(pdev, priv);
242
243 dev_dbg(&pdev->dev, "probed successfully.\n");
244 return 0;
245
246err_irq:
247 serio_unregister_port(pad_serio);
248err_pad:
249 serio_unregister_port(kb_serio);
250 return error;
251}
252
253static int olpc_apsp_remove(struct platform_device *pdev)
254{
255 struct olpc_apsp *priv = platform_get_drvdata(pdev);
256
257 free_irq(priv->irq, priv);
258
259 serio_unregister_port(priv->kbio);
260 serio_unregister_port(priv->padio);
261
262 return 0;
263}
264
265static const struct of_device_id olpc_apsp_dt_ids[] = {
266 { .compatible = "olpc,ap-sp", },
267 {}
268};
269MODULE_DEVICE_TABLE(of, olpc_apsp_dt_ids);
270
271static struct platform_driver olpc_apsp_driver = {
272 .probe = olpc_apsp_probe,
273 .remove = olpc_apsp_remove,
274 .driver = {
275 .name = "olpc-apsp",
276 .of_match_table = olpc_apsp_dt_ids,
277 },
278};
279
280MODULE_DESCRIPTION("OLPC AP-SP serio driver");
281MODULE_LICENSE("GPL");
282module_platform_driver(olpc_apsp_driver);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * OLPC serio driver for multiplexed input from Marvell MMP security processor
4 *
5 * Copyright (C) 2011-2013 One Laptop Per Child
6 */
7
8#include <linux/module.h>
9#include <linux/interrupt.h>
10#include <linux/serio.h>
11#include <linux/err.h>
12#include <linux/platform_device.h>
13#include <linux/io.h>
14#include <linux/of.h>
15#include <linux/slab.h>
16#include <linux/delay.h>
17
18/*
19 * The OLPC XO-1.75 and XO-4 laptops do not have a hardware PS/2 controller.
20 * Instead, the OLPC firmware runs a bit-banging PS/2 implementation on an
21 * otherwise-unused slow processor which is included in the Marvell MMP2/MMP3
22 * SoC, known as the "Security Processor" (SP) or "Wireless Trusted Module"
23 * (WTM). This firmware then reports its results via the WTM registers,
24 * which we read from the Application Processor (AP, i.e. main CPU) in this
25 * driver.
26 *
27 * On the hardware side we have a PS/2 mouse and an AT keyboard, the data
28 * is multiplexed through this system. We create a serio port for each one,
29 * and demultiplex the data accordingly.
30 */
31
32/* WTM register offsets */
33#define SECURE_PROCESSOR_COMMAND 0x40
34#define COMMAND_RETURN_STATUS 0x80
35#define COMMAND_FIFO_STATUS 0xc4
36#define PJ_RST_INTERRUPT 0xc8
37#define PJ_INTERRUPT_MASK 0xcc
38
39/*
40 * The upper byte of SECURE_PROCESSOR_COMMAND and COMMAND_RETURN_STATUS is
41 * used to identify which port (device) is being talked to. The lower byte
42 * is the data being sent/received.
43 */
44#define PORT_MASK 0xff00
45#define DATA_MASK 0x00ff
46#define PORT_SHIFT 8
47#define KEYBOARD_PORT 0
48#define TOUCHPAD_PORT 1
49
50/* COMMAND_FIFO_STATUS */
51#define CMD_CNTR_MASK 0x7 /* Number of pending/unprocessed commands */
52#define MAX_PENDING_CMDS 4 /* from device specs */
53
54/* PJ_RST_INTERRUPT */
55#define SP_COMMAND_COMPLETE_RESET 0x1
56
57/* PJ_INTERRUPT_MASK */
58#define INT_0 (1 << 0)
59
60/* COMMAND_FIFO_STATUS */
61#define CMD_STS_MASK 0x100
62
63struct olpc_apsp {
64 struct device *dev;
65 struct serio *kbio;
66 struct serio *padio;
67 void __iomem *base;
68 int open_count;
69 int irq;
70};
71
72static int olpc_apsp_write(struct serio *port, unsigned char val)
73{
74 struct olpc_apsp *priv = port->port_data;
75 unsigned int i;
76 u32 which = 0;
77
78 if (port == priv->padio)
79 which = TOUCHPAD_PORT << PORT_SHIFT;
80 else
81 which = KEYBOARD_PORT << PORT_SHIFT;
82
83 dev_dbg(priv->dev, "olpc_apsp_write which=%x val=%x\n", which, val);
84 for (i = 0; i < 50; i++) {
85 u32 sts = readl(priv->base + COMMAND_FIFO_STATUS);
86 if ((sts & CMD_CNTR_MASK) < MAX_PENDING_CMDS) {
87 writel(which | val,
88 priv->base + SECURE_PROCESSOR_COMMAND);
89 return 0;
90 }
91 /* SP busy. This has not been seen in practice. */
92 mdelay(1);
93 }
94
95 dev_dbg(priv->dev, "olpc_apsp_write timeout, status=%x\n",
96 readl(priv->base + COMMAND_FIFO_STATUS));
97
98 return -ETIMEDOUT;
99}
100
101static irqreturn_t olpc_apsp_rx(int irq, void *dev_id)
102{
103 struct olpc_apsp *priv = dev_id;
104 unsigned int w, tmp;
105 struct serio *serio;
106
107 /*
108 * Write 1 to PJ_RST_INTERRUPT to acknowledge and clear the interrupt
109 * Write 0xff00 to SECURE_PROCESSOR_COMMAND.
110 */
111 tmp = readl(priv->base + PJ_RST_INTERRUPT);
112 if (!(tmp & SP_COMMAND_COMPLETE_RESET)) {
113 dev_warn(priv->dev, "spurious interrupt?\n");
114 return IRQ_NONE;
115 }
116
117 w = readl(priv->base + COMMAND_RETURN_STATUS);
118 dev_dbg(priv->dev, "olpc_apsp_rx %x\n", w);
119
120 if (w >> PORT_SHIFT == KEYBOARD_PORT)
121 serio = priv->kbio;
122 else
123 serio = priv->padio;
124
125 serio_interrupt(serio, w & DATA_MASK, 0);
126
127 /* Ack and clear interrupt */
128 writel(tmp | SP_COMMAND_COMPLETE_RESET, priv->base + PJ_RST_INTERRUPT);
129 writel(PORT_MASK, priv->base + SECURE_PROCESSOR_COMMAND);
130
131 pm_wakeup_event(priv->dev, 1000);
132 return IRQ_HANDLED;
133}
134
135static int olpc_apsp_open(struct serio *port)
136{
137 struct olpc_apsp *priv = port->port_data;
138 unsigned int tmp;
139 unsigned long l;
140
141 if (priv->open_count++ == 0) {
142 l = readl(priv->base + COMMAND_FIFO_STATUS);
143 if (!(l & CMD_STS_MASK)) {
144 dev_err(priv->dev, "SP cannot accept commands.\n");
145 return -EIO;
146 }
147
148 /* Enable interrupt 0 by clearing its bit */
149 tmp = readl(priv->base + PJ_INTERRUPT_MASK);
150 writel(tmp & ~INT_0, priv->base + PJ_INTERRUPT_MASK);
151 }
152
153 return 0;
154}
155
156static void olpc_apsp_close(struct serio *port)
157{
158 struct olpc_apsp *priv = port->port_data;
159 unsigned int tmp;
160
161 if (--priv->open_count == 0) {
162 /* Disable interrupt 0 */
163 tmp = readl(priv->base + PJ_INTERRUPT_MASK);
164 writel(tmp | INT_0, priv->base + PJ_INTERRUPT_MASK);
165 }
166}
167
168static int olpc_apsp_probe(struct platform_device *pdev)
169{
170 struct serio *kb_serio, *pad_serio;
171 struct olpc_apsp *priv;
172 struct resource *res;
173 int error;
174
175 priv = devm_kzalloc(&pdev->dev, sizeof(struct olpc_apsp), GFP_KERNEL);
176 if (!priv)
177 return -ENOMEM;
178
179 priv->dev = &pdev->dev;
180
181 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
182 priv->base = devm_ioremap_resource(&pdev->dev, res);
183 if (IS_ERR(priv->base)) {
184 dev_err(&pdev->dev, "Failed to map WTM registers\n");
185 return PTR_ERR(priv->base);
186 }
187
188 priv->irq = platform_get_irq(pdev, 0);
189 if (priv->irq < 0)
190 return priv->irq;
191
192 /* KEYBOARD */
193 kb_serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
194 if (!kb_serio)
195 return -ENOMEM;
196 kb_serio->id.type = SERIO_8042_XL;
197 kb_serio->write = olpc_apsp_write;
198 kb_serio->open = olpc_apsp_open;
199 kb_serio->close = olpc_apsp_close;
200 kb_serio->port_data = priv;
201 kb_serio->dev.parent = &pdev->dev;
202 strscpy(kb_serio->name, "sp keyboard", sizeof(kb_serio->name));
203 strscpy(kb_serio->phys, "sp/serio0", sizeof(kb_serio->phys));
204 priv->kbio = kb_serio;
205 serio_register_port(kb_serio);
206
207 /* TOUCHPAD */
208 pad_serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
209 if (!pad_serio) {
210 error = -ENOMEM;
211 goto err_pad;
212 }
213 pad_serio->id.type = SERIO_8042;
214 pad_serio->write = olpc_apsp_write;
215 pad_serio->open = olpc_apsp_open;
216 pad_serio->close = olpc_apsp_close;
217 pad_serio->port_data = priv;
218 pad_serio->dev.parent = &pdev->dev;
219 strscpy(pad_serio->name, "sp touchpad", sizeof(pad_serio->name));
220 strscpy(pad_serio->phys, "sp/serio1", sizeof(pad_serio->phys));
221 priv->padio = pad_serio;
222 serio_register_port(pad_serio);
223
224 error = request_irq(priv->irq, olpc_apsp_rx, 0, "olpc-apsp", priv);
225 if (error) {
226 dev_err(&pdev->dev, "Failed to request IRQ\n");
227 goto err_irq;
228 }
229
230 device_init_wakeup(priv->dev, 1);
231 platform_set_drvdata(pdev, priv);
232
233 dev_dbg(&pdev->dev, "probed successfully.\n");
234 return 0;
235
236err_irq:
237 serio_unregister_port(pad_serio);
238err_pad:
239 serio_unregister_port(kb_serio);
240 return error;
241}
242
243static int olpc_apsp_remove(struct platform_device *pdev)
244{
245 struct olpc_apsp *priv = platform_get_drvdata(pdev);
246
247 free_irq(priv->irq, priv);
248
249 serio_unregister_port(priv->kbio);
250 serio_unregister_port(priv->padio);
251
252 return 0;
253}
254
255static const struct of_device_id olpc_apsp_dt_ids[] = {
256 { .compatible = "olpc,ap-sp", },
257 {}
258};
259MODULE_DEVICE_TABLE(of, olpc_apsp_dt_ids);
260
261static struct platform_driver olpc_apsp_driver = {
262 .probe = olpc_apsp_probe,
263 .remove = olpc_apsp_remove,
264 .driver = {
265 .name = "olpc-apsp",
266 .of_match_table = olpc_apsp_dt_ids,
267 },
268};
269
270MODULE_DESCRIPTION("OLPC AP-SP serio driver");
271MODULE_LICENSE("GPL");
272module_platform_driver(olpc_apsp_driver);