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b56ece9a DD |
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> | |
b56ece9a DD |
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 | ||
72 | struct 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 | ||
81 | static 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 | ||
110 | static 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 | ||
144 | static 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 | ||
158 | static 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 | ||
170 | static 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); | |
b56ece9a DD |
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 | ||
246 | err_irq: | |
247 | serio_unregister_port(pad_serio); | |
248 | err_pad: | |
249 | serio_unregister_port(kb_serio); | |
250 | return error; | |
251 | } | |
252 | ||
253 | static 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 | ||
597173a8 | 265 | static const struct of_device_id olpc_apsp_dt_ids[] = { |
b56ece9a DD |
266 | { .compatible = "olpc,ap-sp", }, |
267 | {} | |
268 | }; | |
269 | MODULE_DEVICE_TABLE(of, olpc_apsp_dt_ids); | |
270 | ||
271 | static struct platform_driver olpc_apsp_driver = { | |
272 | .probe = olpc_apsp_probe, | |
273 | .remove = olpc_apsp_remove, | |
274 | .driver = { | |
275 | .name = "olpc-apsp", | |
b56ece9a DD |
276 | .of_match_table = olpc_apsp_dt_ids, |
277 | }, | |
278 | }; | |
279 | ||
280 | MODULE_DESCRIPTION("OLPC AP-SP serio driver"); | |
281 | MODULE_LICENSE("GPL"); | |
282 | module_platform_driver(olpc_apsp_driver); |