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> 22#include <linux/slab.h> 23#include <linux/init.h> 24#include <linux/list.h> 25#include <linux/io.h> 26 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 | \ 62 XPS2_IPIXR_RX_FULL) 63 64/* Mask for all the Interrupts */ 65#define XPS2_IPIXR_ALL (XPS2_IPIXR_TX_ALL | XPS2_IPIXR_RX_ALL | \ 66 XPS2_IPIXR_WDT_TOUT) 67 68/* Global Interrupt Enable mask */ 69#define XPS2_GIER_GIE_MASK 0x80000000 70 71struct xps2data { 72 int irq; 73 spinlock_t lock; 74 void __iomem *base_address; /* virt. address of control registers */ 75 unsigned int flags; 76 struct serio serio; /* serio */ 77}; 78 79/************************************/ 80/* XPS PS/2 data transmission calls */ 81/************************************/ 82 83/** 84 * xps2_recv() - attempts to receive a byte from the PS/2 port. 85 * @drvdata: pointer to ps2 device private data structure 86 * @byte: address where the read data will be copied 87 * 88 * If there is any data available in the PS/2 receiver, this functions reads 89 * the data, otherwise it returns error. 90 */ 91static int xps2_recv(struct xps2data *drvdata, u8 *byte) 92{ 93 u32 sr; 94 int status = -1; 95 96 /* If there is data available in the PS/2 receiver, read it */ 97 sr = in_be32(drvdata->base_address + XPS2_STATUS_OFFSET); 98 if (sr & XPS2_STATUS_RX_FULL) { 99 *byte = in_be32(drvdata->base_address + XPS2_RX_DATA_OFFSET); 100 status = 0; 101 } 102 103 return status; 104} 105 106/*********************/ 107/* Interrupt handler */ 108/*********************/ 109static irqreturn_t xps2_interrupt(int irq, void *dev_id) 110{ 111 struct xps2data *drvdata = dev_id; 112 u32 intr_sr; 113 u8 c; 114 int status; 115 116 /* Get the PS/2 interrupts and clear them */ 117 intr_sr = in_be32(drvdata->base_address + XPS2_IPISR_OFFSET); 118 out_be32(drvdata->base_address + XPS2_IPISR_OFFSET, intr_sr); 119 120 /* Check which interrupt is active */ 121 if (intr_sr & XPS2_IPIXR_RX_OVF) 122 dev_warn(drvdata->serio.dev.parent, "receive overrun error\n"); 123 124 if (intr_sr & XPS2_IPIXR_RX_ERR) 125 drvdata->flags |= SERIO_PARITY; 126 127 if (intr_sr & (XPS2_IPIXR_TX_NOACK | XPS2_IPIXR_WDT_TOUT)) 128 drvdata->flags |= SERIO_TIMEOUT; 129 130 if (intr_sr & XPS2_IPIXR_RX_FULL) { 131 status = xps2_recv(drvdata, &c); 132 133 /* Error, if a byte is not received */ 134 if (status) { 135 dev_err(drvdata->serio.dev.parent, 136 "wrong rcvd byte count (%d)\n", status); 137 } else { 138 serio_interrupt(&drvdata->serio, c, drvdata->flags); 139 drvdata->flags = 0; 140 } 141 } 142 143 return IRQ_HANDLED; 144} 145 146/*******************/ 147/* serio callbacks */ 148/*******************/ 149 150/** 151 * sxps2_write() - sends a byte out through the PS/2 port. 152 * @pserio: pointer to the serio structure of the PS/2 port 153 * @c: data that needs to be written to the PS/2 port 154 * 155 * This function checks if the PS/2 transmitter is empty and sends a byte. 156 * Otherwise it returns error. Transmission fails only when nothing is connected 157 * to the PS/2 port. Thats why, we do not try to resend the data in case of a 158 * failure. 159 */ 160static int sxps2_write(struct serio *pserio, unsigned char c) 161{ 162 struct xps2data *drvdata = pserio->port_data; 163 unsigned long flags; 164 u32 sr; 165 int status = -1; 166 167 spin_lock_irqsave(&drvdata->lock, flags); 168 169 /* If the PS/2 transmitter is empty send a byte of data */ 170 sr = in_be32(drvdata->base_address + XPS2_STATUS_OFFSET); 171 if (!(sr & XPS2_STATUS_TX_FULL)) { 172 out_be32(drvdata->base_address + XPS2_TX_DATA_OFFSET, c); 173 status = 0; 174 } 175 176 spin_unlock_irqrestore(&drvdata->lock, flags); 177 178 return status; 179} 180 181/** 182 * sxps2_open() - called when a port is opened by the higher layer. 183 * @pserio: pointer to the serio structure of the PS/2 device 184 * 185 * This function requests irq and enables interrupts for the PS/2 device. 186 */ 187static int sxps2_open(struct serio *pserio) 188{ 189 struct xps2data *drvdata = pserio->port_data; 190 int error; 191 u8 c; 192 193 error = request_irq(drvdata->irq, &xps2_interrupt, 0, 194 DRIVER_NAME, drvdata); 195 if (error) { 196 dev_err(drvdata->serio.dev.parent, 197 "Couldn't allocate interrupt %d\n", drvdata->irq); 198 return error; 199 } 200 201 /* start reception by enabling the interrupts */ 202 out_be32(drvdata->base_address + XPS2_GIER_OFFSET, XPS2_GIER_GIE_MASK); 203 out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, XPS2_IPIXR_RX_ALL); 204 (void)xps2_recv(drvdata, &c); 205 206 return 0; /* success */ 207} 208 209/** 210 * sxps2_close() - frees the interrupt. 211 * @pserio: pointer to the serio structure of the PS/2 device 212 * 213 * This function frees the irq and disables interrupts for the PS/2 device. 214 */ 215static void sxps2_close(struct serio *pserio) 216{ 217 struct xps2data *drvdata = pserio->port_data; 218 219 /* Disable the PS2 interrupts */ 220 out_be32(drvdata->base_address + XPS2_GIER_OFFSET, 0x00); 221 out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, 0x00); 222 free_irq(drvdata->irq, drvdata); 223} 224 225/** 226 * xps2_of_probe - probe method for the PS/2 device. 227 * @of_dev: pointer to OF device structure 228 * @match: pointer to the stucture used for matching a device 229 * 230 * This function probes the PS/2 device in the device tree. 231 * It initializes the driver data structure and the hardware. 232 * It returns 0, if the driver is bound to the PS/2 device, or a negative 233 * value if there is an error. 234 */ 235static int __devinit xps2_of_probe(struct platform_device *ofdev, 236 const struct of_device_id *match) 237{ 238 struct resource r_irq; /* Interrupt resources */ 239 struct resource r_mem; /* IO mem resources */ 240 struct xps2data *drvdata; 241 struct serio *serio; 242 struct device *dev = &ofdev->dev; 243 resource_size_t remap_size, phys_addr; 244 int error; 245 246 dev_info(dev, "Device Tree Probing \'%s\'\n", 247 ofdev->dev.of_node->name); 248 249 /* Get iospace for the device */ 250 error = of_address_to_resource(ofdev->dev.of_node, 0, &r_mem); 251 if (error) { 252 dev_err(dev, "invalid address\n"); 253 return error; 254 } 255 256 /* Get IRQ for the device */ 257 if (of_irq_to_resource(ofdev->dev.of_node, 0, &r_irq) == NO_IRQ) { 258 dev_err(dev, "no IRQ found\n"); 259 return -ENODEV; 260 } 261 262 drvdata = kzalloc(sizeof(struct xps2data), GFP_KERNEL); 263 if (!drvdata) { 264 dev_err(dev, "Couldn't allocate device private record\n"); 265 return -ENOMEM; 266 } 267 268 dev_set_drvdata(dev, drvdata); 269 270 spin_lock_init(&drvdata->lock); 271 drvdata->irq = r_irq.start; 272 273 phys_addr = r_mem.start; 274 remap_size = resource_size(&r_mem); 275 if (!request_mem_region(phys_addr, remap_size, DRIVER_NAME)) { 276 dev_err(dev, "Couldn't lock memory region at 0x%08llX\n", 277 (unsigned long long)phys_addr); 278 error = -EBUSY; 279 goto failed1; 280 } 281 282 /* Fill in configuration data and add them to the list */ 283 drvdata->base_address = ioremap(phys_addr, remap_size); 284 if (drvdata->base_address == NULL) { 285 dev_err(dev, "Couldn't ioremap memory at 0x%08llX\n", 286 (unsigned long long)phys_addr); 287 error = -EFAULT; 288 goto failed2; 289 } 290 291 /* Disable all the interrupts, just in case */ 292 out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, 0); 293 294 /* Reset the PS2 device and abort any current transaction, to make sure 295 * we have the PS2 in a good state */ 296 out_be32(drvdata->base_address + XPS2_SRST_OFFSET, XPS2_SRST_RESET); 297 298 dev_info(dev, "Xilinx PS2 at 0x%08llX mapped to 0x%p, irq=%d\n", 299 (unsigned long long)phys_addr, drvdata->base_address, 300 drvdata->irq); 301 302 serio = &drvdata->serio; 303 serio->id.type = SERIO_8042; 304 serio->write = sxps2_write; 305 serio->open = sxps2_open; 306 serio->close = sxps2_close; 307 serio->port_data = drvdata; 308 serio->dev.parent = dev; 309 snprintf(serio->name, sizeof(serio->name), 310 "Xilinx XPS PS/2 at %08llX", (unsigned long long)phys_addr); 311 snprintf(serio->phys, sizeof(serio->phys), 312 "xilinxps2/serio at %08llX", (unsigned long long)phys_addr); 313 314 serio_register_port(serio); 315 316 return 0; /* success */ 317 318failed2: 319 release_mem_region(phys_addr, remap_size); 320failed1: 321 kfree(drvdata); 322 dev_set_drvdata(dev, NULL); 323 324 return error; 325} 326 327/** 328 * xps2_of_remove - unbinds the driver from the PS/2 device. 329 * @of_dev: pointer to OF device structure 330 * 331 * This function is called if a device is physically removed from the system or 332 * if the driver module is being unloaded. It frees any resources allocated to 333 * the device. 334 */ 335static int __devexit xps2_of_remove(struct platform_device *of_dev) 336{ 337 struct device *dev = &of_dev->dev; 338 struct xps2data *drvdata = dev_get_drvdata(dev); 339 struct resource r_mem; /* IO mem resources */ 340 341 serio_unregister_port(&drvdata->serio); 342 iounmap(drvdata->base_address); 343 344 /* Get iospace of the device */ 345 if (of_address_to_resource(of_dev->dev.of_node, 0, &r_mem)) 346 dev_err(dev, "invalid address\n"); 347 else 348 release_mem_region(r_mem.start, resource_size(&r_mem)); 349 350 kfree(drvdata); 351 352 dev_set_drvdata(dev, NULL); 353 354 return 0; 355} 356 357/* Match table for of_platform binding */ 358static const struct of_device_id xps2_of_match[] __devinitconst = { 359 { .compatible = "xlnx,xps-ps2-1.00.a", }, 360 { /* end of list */ }, 361}; 362MODULE_DEVICE_TABLE(of, xps2_of_match); 363 364static struct of_platform_driver xps2_of_driver = { 365 .driver = { 366 .name = DRIVER_NAME, 367 .owner = THIS_MODULE, 368 .of_match_table = xps2_of_match, 369 }, 370 .probe = xps2_of_probe, 371 .remove = __devexit_p(xps2_of_remove), 372}; 373 374static int __init xps2_init(void) 375{ 376 return of_register_platform_driver(&xps2_of_driver); 377} 378 379static void __exit xps2_cleanup(void) 380{ 381 of_unregister_platform_driver(&xps2_of_driver); 382} 383 384module_init(xps2_init); 385module_exit(xps2_cleanup); 386 387MODULE_AUTHOR("Xilinx, Inc."); 388MODULE_DESCRIPTION("Xilinx XPS PS/2 driver"); 389MODULE_LICENSE("GPL"); 390