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1191828f JL |
1 | /* |
2 | * Xilinx XPS PS/2 device driver | |
3 | * | |
4 | * (c) 2005 MontaVista Software, Inc. | |
5 | * (c) 2008 Xilinx, Inc. | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify it | |
8 | * under the terms of the GNU General Public License as published by the | |
9 | * Free Software Foundation; either version 2 of the License, or (at your | |
10 | * option) any later version. | |
11 | * | |
12 | * You should have received a copy of the GNU General Public License along | |
13 | * with this program; if not, write to the Free Software Foundation, Inc., | |
14 | * 675 Mass Ave, Cambridge, MA 02139, USA. | |
15 | */ | |
16 | ||
17 | ||
18 | #include <linux/module.h> | |
19 | #include <linux/serio.h> | |
20 | #include <linux/interrupt.h> | |
21 | #include <linux/errno.h> | |
5a0e3ad6 | 22 | #include <linux/slab.h> |
1191828f JL |
23 | #include <linux/init.h> |
24 | #include <linux/list.h> | |
25 | #include <linux/io.h> | |
5f9288af | 26 | #include <linux/of_address.h> |
1191828f JL |
27 | #include <linux/of_device.h> |
28 | #include <linux/of_platform.h> | |
29 | ||
30 | #define DRIVER_NAME "xilinx_ps2" | |
31 | ||
32 | /* Register offsets for the xps2 device */ | |
33 | #define XPS2_SRST_OFFSET 0x00000000 /* Software Reset register */ | |
34 | #define XPS2_STATUS_OFFSET 0x00000004 /* Status register */ | |
35 | #define XPS2_RX_DATA_OFFSET 0x00000008 /* Receive Data register */ | |
36 | #define XPS2_TX_DATA_OFFSET 0x0000000C /* Transmit Data register */ | |
37 | #define XPS2_GIER_OFFSET 0x0000002C /* Global Interrupt Enable reg */ | |
38 | #define XPS2_IPISR_OFFSET 0x00000030 /* Interrupt Status register */ | |
39 | #define XPS2_IPIER_OFFSET 0x00000038 /* Interrupt Enable register */ | |
40 | ||
41 | /* Reset Register Bit Definitions */ | |
42 | #define XPS2_SRST_RESET 0x0000000A /* Software Reset */ | |
43 | ||
44 | /* Status Register Bit Positions */ | |
45 | #define XPS2_STATUS_RX_FULL 0x00000001 /* Receive Full */ | |
46 | #define XPS2_STATUS_TX_FULL 0x00000002 /* Transmit Full */ | |
47 | ||
48 | /* Bit definitions for ISR/IER registers. Both the registers have the same bit | |
49 | * definitions and are only defined once. */ | |
50 | #define XPS2_IPIXR_WDT_TOUT 0x00000001 /* Watchdog Timeout Interrupt */ | |
51 | #define XPS2_IPIXR_TX_NOACK 0x00000002 /* Transmit No ACK Interrupt */ | |
52 | #define XPS2_IPIXR_TX_ACK 0x00000004 /* Transmit ACK (Data) Interrupt */ | |
53 | #define XPS2_IPIXR_RX_OVF 0x00000008 /* Receive Overflow Interrupt */ | |
54 | #define XPS2_IPIXR_RX_ERR 0x00000010 /* Receive Error Interrupt */ | |
55 | #define XPS2_IPIXR_RX_FULL 0x00000020 /* Receive Data Interrupt */ | |
56 | ||
57 | /* Mask for all the Transmit Interrupts */ | |
58 | #define XPS2_IPIXR_TX_ALL (XPS2_IPIXR_TX_NOACK | XPS2_IPIXR_TX_ACK) | |
59 | ||
60 | /* Mask for all the Receive Interrupts */ | |
61 | #define XPS2_IPIXR_RX_ALL (XPS2_IPIXR_RX_OVF | XPS2_IPIXR_RX_ERR | \ | |
b4a3ac9a | 62 | XPS2_IPIXR_RX_FULL) |
1191828f JL |
63 | |
64 | /* Mask for all the Interrupts */ | |
65 | #define XPS2_IPIXR_ALL (XPS2_IPIXR_TX_ALL | XPS2_IPIXR_RX_ALL | \ | |
b4a3ac9a | 66 | XPS2_IPIXR_WDT_TOUT) |
1191828f JL |
67 | |
68 | /* Global Interrupt Enable mask */ | |
69 | #define XPS2_GIER_GIE_MASK 0x80000000 | |
70 | ||
71 | struct xps2data { | |
72 | int irq; | |
1191828f | 73 | spinlock_t lock; |
1191828f | 74 | void __iomem *base_address; /* virt. address of control registers */ |
b4a3ac9a | 75 | unsigned int flags; |
271002ca DT |
76 | struct serio *serio; /* serio */ |
77 | struct device *dev; | |
1191828f JL |
78 | }; |
79 | ||
80 | /************************************/ | |
81 | /* XPS PS/2 data transmission calls */ | |
82 | /************************************/ | |
83 | ||
b4a3ac9a JL |
84 | /** |
85 | * xps2_recv() - attempts to receive a byte from the PS/2 port. | |
86 | * @drvdata: pointer to ps2 device private data structure | |
87 | * @byte: address where the read data will be copied | |
88 | * | |
89 | * If there is any data available in the PS/2 receiver, this functions reads | |
90 | * the data, otherwise it returns error. | |
1191828f JL |
91 | */ |
92 | static int xps2_recv(struct xps2data *drvdata, u8 *byte) | |
93 | { | |
94 | u32 sr; | |
95 | int status = -1; | |
96 | ||
97 | /* If there is data available in the PS/2 receiver, read it */ | |
98 | sr = in_be32(drvdata->base_address + XPS2_STATUS_OFFSET); | |
99 | if (sr & XPS2_STATUS_RX_FULL) { | |
100 | *byte = in_be32(drvdata->base_address + XPS2_RX_DATA_OFFSET); | |
101 | status = 0; | |
102 | } | |
103 | ||
104 | return status; | |
105 | } | |
106 | ||
107 | /*********************/ | |
108 | /* Interrupt handler */ | |
109 | /*********************/ | |
110 | static irqreturn_t xps2_interrupt(int irq, void *dev_id) | |
111 | { | |
112 | struct xps2data *drvdata = dev_id; | |
113 | u32 intr_sr; | |
114 | u8 c; | |
115 | int status; | |
116 | ||
117 | /* Get the PS/2 interrupts and clear them */ | |
118 | intr_sr = in_be32(drvdata->base_address + XPS2_IPISR_OFFSET); | |
119 | out_be32(drvdata->base_address + XPS2_IPISR_OFFSET, intr_sr); | |
120 | ||
121 | /* Check which interrupt is active */ | |
122 | if (intr_sr & XPS2_IPIXR_RX_OVF) | |
271002ca | 123 | dev_warn(drvdata->dev, "receive overrun error\n"); |
1191828f JL |
124 | |
125 | if (intr_sr & XPS2_IPIXR_RX_ERR) | |
b4a3ac9a | 126 | drvdata->flags |= SERIO_PARITY; |
1191828f JL |
127 | |
128 | if (intr_sr & (XPS2_IPIXR_TX_NOACK | XPS2_IPIXR_WDT_TOUT)) | |
b4a3ac9a | 129 | drvdata->flags |= SERIO_TIMEOUT; |
1191828f JL |
130 | |
131 | if (intr_sr & XPS2_IPIXR_RX_FULL) { | |
b4a3ac9a | 132 | status = xps2_recv(drvdata, &c); |
1191828f JL |
133 | |
134 | /* Error, if a byte is not received */ | |
135 | if (status) { | |
271002ca | 136 | dev_err(drvdata->dev, |
b4a3ac9a | 137 | "wrong rcvd byte count (%d)\n", status); |
1191828f | 138 | } else { |
271002ca | 139 | serio_interrupt(drvdata->serio, c, drvdata->flags); |
b4a3ac9a | 140 | drvdata->flags = 0; |
1191828f JL |
141 | } |
142 | } | |
143 | ||
1191828f JL |
144 | return IRQ_HANDLED; |
145 | } | |
146 | ||
147 | /*******************/ | |
148 | /* serio callbacks */ | |
149 | /*******************/ | |
150 | ||
b4a3ac9a JL |
151 | /** |
152 | * sxps2_write() - sends a byte out through the PS/2 port. | |
153 | * @pserio: pointer to the serio structure of the PS/2 port | |
154 | * @c: data that needs to be written to the PS/2 port | |
155 | * | |
156 | * This function checks if the PS/2 transmitter is empty and sends a byte. | |
157 | * Otherwise it returns error. Transmission fails only when nothing is connected | |
158 | * to the PS/2 port. Thats why, we do not try to resend the data in case of a | |
159 | * failure. | |
1191828f JL |
160 | */ |
161 | static int sxps2_write(struct serio *pserio, unsigned char c) | |
162 | { | |
163 | struct xps2data *drvdata = pserio->port_data; | |
164 | unsigned long flags; | |
165 | u32 sr; | |
166 | int status = -1; | |
167 | ||
168 | spin_lock_irqsave(&drvdata->lock, flags); | |
169 | ||
170 | /* If the PS/2 transmitter is empty send a byte of data */ | |
171 | sr = in_be32(drvdata->base_address + XPS2_STATUS_OFFSET); | |
172 | if (!(sr & XPS2_STATUS_TX_FULL)) { | |
173 | out_be32(drvdata->base_address + XPS2_TX_DATA_OFFSET, c); | |
174 | status = 0; | |
175 | } | |
176 | ||
177 | spin_unlock_irqrestore(&drvdata->lock, flags); | |
178 | ||
179 | return status; | |
180 | } | |
181 | ||
b4a3ac9a JL |
182 | /** |
183 | * sxps2_open() - called when a port is opened by the higher layer. | |
184 | * @pserio: pointer to the serio structure of the PS/2 device | |
185 | * | |
186 | * This function requests irq and enables interrupts for the PS/2 device. | |
1191828f JL |
187 | */ |
188 | static int sxps2_open(struct serio *pserio) | |
189 | { | |
190 | struct xps2data *drvdata = pserio->port_data; | |
b4a3ac9a JL |
191 | int error; |
192 | u8 c; | |
1191828f | 193 | |
b4a3ac9a | 194 | error = request_irq(drvdata->irq, &xps2_interrupt, 0, |
1191828f | 195 | DRIVER_NAME, drvdata); |
b4a3ac9a | 196 | if (error) { |
271002ca | 197 | dev_err(drvdata->dev, |
b4a3ac9a JL |
198 | "Couldn't allocate interrupt %d\n", drvdata->irq); |
199 | return error; | |
1191828f JL |
200 | } |
201 | ||
202 | /* start reception by enabling the interrupts */ | |
203 | out_be32(drvdata->base_address + XPS2_GIER_OFFSET, XPS2_GIER_GIE_MASK); | |
204 | out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, XPS2_IPIXR_RX_ALL); | |
b4a3ac9a | 205 | (void)xps2_recv(drvdata, &c); |
1191828f JL |
206 | |
207 | return 0; /* success */ | |
208 | } | |
209 | ||
b4a3ac9a JL |
210 | /** |
211 | * sxps2_close() - frees the interrupt. | |
212 | * @pserio: pointer to the serio structure of the PS/2 device | |
213 | * | |
214 | * This function frees the irq and disables interrupts for the PS/2 device. | |
1191828f JL |
215 | */ |
216 | static void sxps2_close(struct serio *pserio) | |
217 | { | |
218 | struct xps2data *drvdata = pserio->port_data; | |
219 | ||
220 | /* Disable the PS2 interrupts */ | |
221 | out_be32(drvdata->base_address + XPS2_GIER_OFFSET, 0x00); | |
222 | out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, 0x00); | |
223 | free_irq(drvdata->irq, drvdata); | |
224 | } | |
225 | ||
b4a3ac9a JL |
226 | /** |
227 | * xps2_of_probe - probe method for the PS/2 device. | |
228 | * @of_dev: pointer to OF device structure | |
25985edc | 229 | * @match: pointer to the structure used for matching a device |
b4a3ac9a JL |
230 | * |
231 | * This function probes the PS/2 device in the device tree. | |
232 | * It initializes the driver data structure and the hardware. | |
233 | * It returns 0, if the driver is bound to the PS/2 device, or a negative | |
234 | * value if there is an error. | |
235 | */ | |
5298cc4c | 236 | static int xps2_of_probe(struct platform_device *ofdev) |
1191828f | 237 | { |
b4a3ac9a | 238 | struct resource r_mem; /* IO mem resources */ |
1191828f JL |
239 | struct xps2data *drvdata; |
240 | struct serio *serio; | |
b4a3ac9a JL |
241 | struct device *dev = &ofdev->dev; |
242 | resource_size_t remap_size, phys_addr; | |
f7578496 | 243 | unsigned int irq; |
b4a3ac9a JL |
244 | int error; |
245 | ||
246 | dev_info(dev, "Device Tree Probing \'%s\'\n", | |
61c7a080 | 247 | ofdev->dev.of_node->name); |
1191828f | 248 | |
b4a3ac9a | 249 | /* Get iospace for the device */ |
61c7a080 | 250 | error = of_address_to_resource(ofdev->dev.of_node, 0, &r_mem); |
b4a3ac9a JL |
251 | if (error) { |
252 | dev_err(dev, "invalid address\n"); | |
253 | return error; | |
254 | } | |
1191828f | 255 | |
b4a3ac9a | 256 | /* Get IRQ for the device */ |
f7578496 TR |
257 | irq = irq_of_parse_and_map(ofdev->dev.of_node, 0); |
258 | if (!irq) { | |
b4a3ac9a JL |
259 | dev_err(dev, "no IRQ found\n"); |
260 | return -ENODEV; | |
1191828f JL |
261 | } |
262 | ||
263 | drvdata = kzalloc(sizeof(struct xps2data), GFP_KERNEL); | |
271002ca DT |
264 | serio = kzalloc(sizeof(struct serio), GFP_KERNEL); |
265 | if (!drvdata || !serio) { | |
266 | error = -ENOMEM; | |
267 | goto failed1; | |
1191828f JL |
268 | } |
269 | ||
1191828f | 270 | spin_lock_init(&drvdata->lock); |
f7578496 | 271 | drvdata->irq = irq; |
271002ca DT |
272 | drvdata->serio = serio; |
273 | drvdata->dev = dev; | |
b4a3ac9a JL |
274 | |
275 | phys_addr = r_mem.start; | |
ce841b94 | 276 | remap_size = resource_size(&r_mem); |
b4a3ac9a JL |
277 | if (!request_mem_region(phys_addr, remap_size, DRIVER_NAME)) { |
278 | dev_err(dev, "Couldn't lock memory region at 0x%08llX\n", | |
279 | (unsigned long long)phys_addr); | |
280 | error = -EBUSY; | |
1191828f JL |
281 | goto failed1; |
282 | } | |
283 | ||
284 | /* Fill in configuration data and add them to the list */ | |
b4a3ac9a | 285 | drvdata->base_address = ioremap(phys_addr, remap_size); |
1191828f | 286 | if (drvdata->base_address == NULL) { |
b4a3ac9a JL |
287 | dev_err(dev, "Couldn't ioremap memory at 0x%08llX\n", |
288 | (unsigned long long)phys_addr); | |
289 | error = -EFAULT; | |
1191828f JL |
290 | goto failed2; |
291 | } | |
292 | ||
293 | /* Disable all the interrupts, just in case */ | |
294 | out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, 0); | |
295 | ||
296 | /* Reset the PS2 device and abort any current transaction, to make sure | |
297 | * we have the PS2 in a good state */ | |
298 | out_be32(drvdata->base_address + XPS2_SRST_OFFSET, XPS2_SRST_RESET); | |
299 | ||
b4a3ac9a JL |
300 | dev_info(dev, "Xilinx PS2 at 0x%08llX mapped to 0x%p, irq=%d\n", |
301 | (unsigned long long)phys_addr, drvdata->base_address, | |
302 | drvdata->irq); | |
1191828f | 303 | |
1191828f JL |
304 | serio->id.type = SERIO_8042; |
305 | serio->write = sxps2_write; | |
306 | serio->open = sxps2_open; | |
307 | serio->close = sxps2_close; | |
308 | serio->port_data = drvdata; | |
309 | serio->dev.parent = dev; | |
310 | snprintf(serio->name, sizeof(serio->name), | |
b4a3ac9a | 311 | "Xilinx XPS PS/2 at %08llX", (unsigned long long)phys_addr); |
1191828f | 312 | snprintf(serio->phys, sizeof(serio->phys), |
b4a3ac9a JL |
313 | "xilinxps2/serio at %08llX", (unsigned long long)phys_addr); |
314 | ||
1191828f JL |
315 | serio_register_port(serio); |
316 | ||
271002ca | 317 | platform_set_drvdata(ofdev, drvdata); |
1191828f JL |
318 | return 0; /* success */ |
319 | ||
320 | failed2: | |
b4a3ac9a | 321 | release_mem_region(phys_addr, remap_size); |
1191828f | 322 | failed1: |
271002ca | 323 | kfree(serio); |
1191828f | 324 | kfree(drvdata); |
1191828f | 325 | |
b4a3ac9a | 326 | return error; |
1191828f JL |
327 | } |
328 | ||
b4a3ac9a JL |
329 | /** |
330 | * xps2_of_remove - unbinds the driver from the PS/2 device. | |
331 | * @of_dev: pointer to OF device structure | |
332 | * | |
333 | * This function is called if a device is physically removed from the system or | |
334 | * if the driver module is being unloaded. It frees any resources allocated to | |
335 | * the device. | |
336 | */ | |
e2619cf7 | 337 | static int xps2_of_remove(struct platform_device *of_dev) |
1191828f | 338 | { |
271002ca | 339 | struct xps2data *drvdata = platform_get_drvdata(of_dev); |
b4a3ac9a | 340 | struct resource r_mem; /* IO mem resources */ |
1191828f | 341 | |
271002ca | 342 | serio_unregister_port(drvdata->serio); |
1191828f | 343 | iounmap(drvdata->base_address); |
b4a3ac9a JL |
344 | |
345 | /* Get iospace of the device */ | |
61c7a080 | 346 | if (of_address_to_resource(of_dev->dev.of_node, 0, &r_mem)) |
271002ca | 347 | dev_err(drvdata->dev, "invalid address\n"); |
b4a3ac9a | 348 | else |
ce841b94 | 349 | release_mem_region(r_mem.start, resource_size(&r_mem)); |
b4a3ac9a | 350 | |
1191828f JL |
351 | kfree(drvdata); |
352 | ||
b4a3ac9a | 353 | return 0; |
1191828f JL |
354 | } |
355 | ||
356 | /* Match table for of_platform binding */ | |
78f50c24 | 357 | static const struct of_device_id xps2_of_match[] = { |
1191828f JL |
358 | { .compatible = "xlnx,xps-ps2-1.00.a", }, |
359 | { /* end of list */ }, | |
360 | }; | |
361 | MODULE_DEVICE_TABLE(of, xps2_of_match); | |
362 | ||
1c48a5c9 | 363 | static struct platform_driver xps2_of_driver = { |
4018294b GL |
364 | .driver = { |
365 | .name = DRIVER_NAME, | |
366 | .owner = THIS_MODULE, | |
367 | .of_match_table = xps2_of_match, | |
368 | }, | |
1191828f | 369 | .probe = xps2_of_probe, |
1cb0aa88 | 370 | .remove = xps2_of_remove, |
1191828f | 371 | }; |
24d2469a | 372 | module_platform_driver(xps2_of_driver); |
1191828f JL |
373 | |
374 | MODULE_AUTHOR("Xilinx, Inc."); | |
375 | MODULE_DESCRIPTION("Xilinx XPS PS/2 driver"); | |
376 | MODULE_LICENSE("GPL"); | |
377 |