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 71 struct 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 */ 91 static 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 /*********************/ 109 static 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 */ 160 static 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 */ 187 static 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 */ 215 static 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 structure 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 */ 235 static int __devinit xps2_of_probe(struct platform_device *ofdev) 236 { 237 struct resource r_irq; /* Interrupt resources */ 238 struct resource r_mem; /* IO mem resources */ 239 struct xps2data *drvdata; 240 struct serio *serio; 241 struct device *dev = &ofdev->dev; 242 resource_size_t remap_size, phys_addr; 243 int error; 244 245 dev_info(dev, "Device Tree Probing \'%s\'\n", 246 ofdev->dev.of_node->name); 247 248 /* Get iospace for the device */ 249 error = of_address_to_resource(ofdev->dev.of_node, 0, &r_mem); 250 if (error) { 251 dev_err(dev, "invalid address\n"); 252 return error; 253 } 254 255 /* Get IRQ for the device */ 256 if (of_irq_to_resource(ofdev->dev.of_node, 0, &r_irq) == NO_IRQ) { 257 dev_err(dev, "no IRQ found\n"); 258 return -ENODEV; 259 } 260 261 drvdata = kzalloc(sizeof(struct xps2data), GFP_KERNEL); 262 if (!drvdata) { 263 dev_err(dev, "Couldn't allocate device private record\n"); 264 return -ENOMEM; 265 } 266 267 dev_set_drvdata(dev, drvdata); 268 269 spin_lock_init(&drvdata->lock); 270 drvdata->irq = r_irq.start; 271 272 phys_addr = r_mem.start; 273 remap_size = resource_size(&r_mem); 274 if (!request_mem_region(phys_addr, remap_size, DRIVER_NAME)) { 275 dev_err(dev, "Couldn't lock memory region at 0x%08llX\n", 276 (unsigned long long)phys_addr); 277 error = -EBUSY; 278 goto failed1; 279 } 280 281 /* Fill in configuration data and add them to the list */ 282 drvdata->base_address = ioremap(phys_addr, remap_size); 283 if (drvdata->base_address == NULL) { 284 dev_err(dev, "Couldn't ioremap memory at 0x%08llX\n", 285 (unsigned long long)phys_addr); 286 error = -EFAULT; 287 goto failed2; 288 } 289 290 /* Disable all the interrupts, just in case */ 291 out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, 0); 292 293 /* Reset the PS2 device and abort any current transaction, to make sure 294 * we have the PS2 in a good state */ 295 out_be32(drvdata->base_address + XPS2_SRST_OFFSET, XPS2_SRST_RESET); 296 297 dev_info(dev, "Xilinx PS2 at 0x%08llX mapped to 0x%p, irq=%d\n", 298 (unsigned long long)phys_addr, drvdata->base_address, 299 drvdata->irq); 300 301 serio = &drvdata->serio; 302 serio->id.type = SERIO_8042; 303 serio->write = sxps2_write; 304 serio->open = sxps2_open; 305 serio->close = sxps2_close; 306 serio->port_data = drvdata; 307 serio->dev.parent = dev; 308 snprintf(serio->name, sizeof(serio->name), 309 "Xilinx XPS PS/2 at %08llX", (unsigned long long)phys_addr); 310 snprintf(serio->phys, sizeof(serio->phys), 311 "xilinxps2/serio at %08llX", (unsigned long long)phys_addr); 312 313 serio_register_port(serio); 314 315 return 0; /* success */ 316 317 failed2: 318 release_mem_region(phys_addr, remap_size); 319 failed1: 320 kfree(drvdata); 321 dev_set_drvdata(dev, NULL); 322 323 return error; 324 } 325 326 /** 327 * xps2_of_remove - unbinds the driver from the PS/2 device. 328 * @of_dev: pointer to OF device structure 329 * 330 * This function is called if a device is physically removed from the system or 331 * if the driver module is being unloaded. It frees any resources allocated to 332 * the device. 333 */ 334 static int __devexit xps2_of_remove(struct platform_device *of_dev) 335 { 336 struct device *dev = &of_dev->dev; 337 struct xps2data *drvdata = dev_get_drvdata(dev); 338 struct resource r_mem; /* IO mem resources */ 339 340 serio_unregister_port(&drvdata->serio); 341 iounmap(drvdata->base_address); 342 343 /* Get iospace of the device */ 344 if (of_address_to_resource(of_dev->dev.of_node, 0, &r_mem)) 345 dev_err(dev, "invalid address\n"); 346 else 347 release_mem_region(r_mem.start, resource_size(&r_mem)); 348 349 kfree(drvdata); 350 351 dev_set_drvdata(dev, NULL); 352 353 return 0; 354 } 355 356 /* Match table for of_platform binding */ 357 static const struct of_device_id xps2_of_match[] __devinitconst = { 358 { .compatible = "xlnx,xps-ps2-1.00.a", }, 359 { /* end of list */ }, 360 }; 361 MODULE_DEVICE_TABLE(of, xps2_of_match); 362 363 static struct platform_driver xps2_of_driver = { 364 .driver = { 365 .name = DRIVER_NAME, 366 .owner = THIS_MODULE, 367 .of_match_table = xps2_of_match, 368 }, 369 .probe = xps2_of_probe, 370 .remove = __devexit_p(xps2_of_remove), 371 }; 372 373 static int __init xps2_init(void) 374 { 375 return platform_driver_register(&xps2_of_driver); 376 } 377 378 static void __exit xps2_cleanup(void) 379 { 380 platform_driver_unregister(&xps2_of_driver); 381 } 382 383 module_init(xps2_init); 384 module_exit(xps2_cleanup); 385 386 MODULE_AUTHOR("Xilinx, Inc."); 387 MODULE_DESCRIPTION("Xilinx XPS PS/2 driver"); 388 MODULE_LICENSE("GPL"); 389 390