drivers/char/xilinx_hwicap/buffer_icap.c

   1 /*****************************************************************************
   2  *
   3  *     Author: Xilinx, Inc.
   4  *
   5  *     This program is free software; you can redistribute it and/or modify it
   6  *     under the terms of the GNU General Public License as published by the
   7  *     Free Software Foundation; either version 2 of the License, or (at your
   8  *     option) any later version.
   9  *
  10  *     XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS"
  11  *     AS A COURTESY TO YOU, SOLELY FOR USE IN DEVELOPING PROGRAMS AND
  12  *     SOLUTIONS FOR XILINX DEVICES.  BY PROVIDING THIS DESIGN, CODE,
  13  *     OR INFORMATION AS ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE,
  14  *     APPLICATION OR STANDARD, XILINX IS MAKING NO REPRESENTATION
  15  *     THAT THIS IMPLEMENTATION IS FREE FROM ANY CLAIMS OF INFRINGEMENT,
  16  *     AND YOU ARE RESPONSIBLE FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE
  17  *     FOR YOUR IMPLEMENTATION.  XILINX EXPRESSLY DISCLAIMS ANY
  18  *     WARRANTY WHATSOEVER WITH RESPECT TO THE ADEQUACY OF THE
  19  *     IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OR
  20  *     REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE FROM CLAIMS OF
  21  *     INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  22  *     FOR A PARTICULAR PURPOSE.
  23  *
  24  *     (c) Copyright 2003-2008 Xilinx Inc.
  25  *     All rights reserved.
  26  *
  27  *     You should have received a copy of the GNU General Public License along
  28  *     with this program; if not, write to the Free Software Foundation, Inc.,
  29  *     675 Mass Ave, Cambridge, MA 02139, USA.
  30  *
  31  *****************************************************************************/
  32
  33 #include "buffer_icap.h"
  34
  35 /* Indicates how many bytes will fit in a buffer. (1 BRAM) */
  36 #define XHI_MAX_BUFFER_BYTES        2048
  37 #define XHI_MAX_BUFFER_INTS         (XHI_MAX_BUFFER_BYTES >> 2)
  38
  39 /* File access and error constants */
  40 #define XHI_DEVICE_READ_ERROR       -1
  41 #define XHI_DEVICE_WRITE_ERROR      -2
  42 #define XHI_BUFFER_OVERFLOW_ERROR   -3
  43
  44 #define XHI_DEVICE_READ             0x1
  45 #define XHI_DEVICE_WRITE            0x0
  46
  47 /* Constants for checking transfer status */
  48 #define XHI_CYCLE_DONE              0
  49 #define XHI_CYCLE_EXECUTING         1
  50
  51 /* buffer_icap register offsets */
  52
  53 /* Size of transfer, read & write */
  54 #define XHI_SIZE_REG_OFFSET        0x800L
  55 /* offset into bram, read & write */
  56 #define XHI_BRAM_OFFSET_REG_OFFSET 0x804L
  57 /* Read not Configure, direction of transfer.  Write only */
  58 #define XHI_RNC_REG_OFFSET         0x808L
  59 /* Indicates transfer complete. Read only */
  60 #define XHI_STATUS_REG_OFFSET      0x80CL
  61
  62 /* Constants for setting the RNC register */
  63 #define XHI_CONFIGURE              0x0UL
  64 #define XHI_READBACK               0x1UL
  65
  66 /* Constants for the Done register */
  67 #define XHI_NOT_FINISHED           0x0UL
  68 #define XHI_FINISHED               0x1UL
  69
  70 #define XHI_BUFFER_START 0
  71
  72 /**
  73  * buffer_icap_get_status - Get the contents of the status register.
  74  * @drvdata: a pointer to the drvdata.
  75  *
  76  * The status register contains the ICAP status and the done bit.
  77  *
  78  * D8 - cfgerr
  79  * D7 - dalign
  80  * D6 - rip
  81  * D5 - in_abort_l
  82  * D4 - Always 1
  83  * D3 - Always 1
  84  * D2 - Always 1
  85  * D1 - Always 1
  86  * D0 - Done bit
  87  **/
  88 u32 buffer_icap_get_status(struct hwicap_drvdata *drvdata)
  89 {
  90         return in_be32(drvdata->base_address + XHI_STATUS_REG_OFFSET);
  91 }
  92
  93 /**
  94  * buffer_icap_get_bram - Reads data from the storage buffer bram.
  95  * @base_address: contains the base address of the component.
  96  * @offset: The word offset from which the data should be read.
  97  *
  98  * A bram is used as a configuration memory cache.  One frame of data can
  99  * be stored in this "storage buffer".
 100  **/
 101 static inline u32 buffer_icap_get_bram(void __iomem *base_address,
 102                 u32 offset)
 103 {
 104         return in_be32(base_address + (offset << 2));
 105 }
 106
 107 /**
 108  * buffer_icap_busy - Return true if the icap device is busy
 109  * @base_address: is the base address of the device
 110  *
 111  * The queries the low order bit of the status register, which
 112  * indicates whether the current configuration or readback operation
 113  * has completed.
 114  **/
 115 static inline bool buffer_icap_busy(void __iomem *base_address)
 116 {
 117         u32 status = in_be32(base_address + XHI_STATUS_REG_OFFSET);
 118         return (status & 1) == XHI_NOT_FINISHED;
 119 }
 120
 121 /**
 122  * buffer_icap_set_size - Set the size register.
 123  * @base_address: is the base address of the device
 124  * @data: The size in bytes.
 125  *
 126  * The size register holds the number of 8 bit bytes to transfer between
 127  * bram and the icap (or icap to bram).
 128  **/
 129 static inline void buffer_icap_set_size(void __iomem *base_address,
 130                 u32 data)
 131 {
 132         out_be32(base_address + XHI_SIZE_REG_OFFSET, data);
 133 }
 134
 135 /**
 136  * buffer_icap_set_offset - Set the bram offset register.
 137  * @base_address: contains the base address of the device.
 138  * @data: is the value to be written to the data register.
 139  *
 140  * The bram offset register holds the starting bram address to transfer
 141  * data from during configuration or write data to during readback.
 142  **/
 143 static inline void buffer_icap_set_offset(void __iomem *base_address,
 144                 u32 data)
 145 {
 146         out_be32(base_address + XHI_BRAM_OFFSET_REG_OFFSET, data);
 147 }
 148
 149 /**
 150  * buffer_icap_set_rnc - Set the RNC (Readback not Configure) register.
 151  * @base_address: contains the base address of the device.
 152  * @data: is the value to be written to the data register.
 153  *
 154  * The RNC register determines the direction of the data transfer.  It
 155  * controls whether a configuration or readback take place.  Writing to
 156  * this register initiates the transfer.  A value of 1 initiates a
 157  * readback while writing a value of 0 initiates a configuration.
 158  **/
 159 static inline void buffer_icap_set_rnc(void __iomem *base_address,
 160                 u32 data)
 161 {
 162         out_be32(base_address + XHI_RNC_REG_OFFSET, data);
 163 }
 164
 165 /**
 166  * buffer_icap_set_bram - Write data to the storage buffer bram.
 167  * @base_address: contains the base address of the component.
 168  * @offset: The word offset at which the data should be written.
 169  * @data: The value to be written to the bram offset.
 170  *
 171  * A bram is used as a configuration memory cache.  One frame of data can
 172  * be stored in this "storage buffer".
 173  **/
 174 static inline void buffer_icap_set_bram(void __iomem *base_address,
 175                 u32 offset, u32 data)
 176 {
 177         out_be32(base_address + (offset << 2), data);
 178 }
 179
 180 /**
 181  * buffer_icap_device_read - Transfer bytes from ICAP to the storage buffer.
 182  * @drvdata: a pointer to the drvdata.
 183  * @offset: The storage buffer start address.
 184  * @count: The number of words (32 bit) to read from the
 185  *           device (ICAP).
 186  **/
 187 static int buffer_icap_device_read(struct hwicap_drvdata *drvdata,
 188                 u32 offset, u32 count)
 189 {
 190
 191         s32 retries = 0;
 192         void __iomem *base_address = drvdata->base_address;
 193
 194         if (buffer_icap_busy(base_address))
 195                 return -EBUSY;
 196
 197         if ((offset + count) > XHI_MAX_BUFFER_INTS)
 198                 return -EINVAL;
 199
 200         /* setSize count*4 to get bytes. */
 201         buffer_icap_set_size(base_address, (count << 2));
 202         buffer_icap_set_offset(base_address, offset);
 203         buffer_icap_set_rnc(base_address, XHI_READBACK);
 204
 205         while (buffer_icap_busy(base_address)) {
 206                 retries++;
 207                 if (retries > XHI_MAX_RETRIES)
 208                         return -EBUSY;
 209         }
 210         return 0;
 211
 212 };
 213
 214 /**
 215  * buffer_icap_device_write - Transfer bytes from ICAP to the storage buffer.
 216  * @drvdata: a pointer to the drvdata.
 217  * @offset: The storage buffer start address.
 218  * @count: The number of words (32 bit) to read from the
 219  *           device (ICAP).
 220  **/
 221 static int buffer_icap_device_write(struct hwicap_drvdata *drvdata,
 222                 u32 offset, u32 count)
 223 {
 224
 225         s32 retries = 0;
 226         void __iomem *base_address = drvdata->base_address;
 227
 228         if (buffer_icap_busy(base_address))
 229                 return -EBUSY;
 230
 231         if ((offset + count) > XHI_MAX_BUFFER_INTS)
 232                 return -EINVAL;
 233
 234         /* setSize count*4 to get bytes. */
 235         buffer_icap_set_size(base_address, count << 2);
 236         buffer_icap_set_offset(base_address, offset);
 237         buffer_icap_set_rnc(base_address, XHI_CONFIGURE);
 238
 239         while (buffer_icap_busy(base_address)) {
 240                 retries++;
 241                 if (retries > XHI_MAX_RETRIES)
 242                         return -EBUSY;
 243         }
 244         return 0;
 245
 246 };
 247
 248 /**
 249  * buffer_icap_reset - Reset the logic of the icap device.
 250  * @drvdata: a pointer to the drvdata.
 251  *
 252  * Writing to the status register resets the ICAP logic in an internal
 253  * version of the core.  For the version of the core published in EDK,
 254  * this is a noop.
 255  **/
 256 void buffer_icap_reset(struct hwicap_drvdata *drvdata)
 257 {
 258     out_be32(drvdata->base_address + XHI_STATUS_REG_OFFSET, 0xFEFE);
 259 }
 260
 261 /**
 262  * buffer_icap_set_configuration - Load a partial bitstream from system memory.
 263  * @drvdata: a pointer to the drvdata.
 264  * @data: Kernel address of the partial bitstream.
 265  * @size: the size of the partial bitstream in 32 bit words.
 266  **/
 267 int buffer_icap_set_configuration(struct hwicap_drvdata *drvdata, u32 *data,
 268                              u32 size)
 269 {
 270         int status;
 271         s32 buffer_count = 0;
 272         bool dirty = false;
 273         u32 i;
 274         void __iomem *base_address = drvdata->base_address;
 275
 276         /* Loop through all the data */
 277         for (i = 0, buffer_count = 0; i < size; i++) {
 278
 279                 /* Copy data to bram */
 280                 buffer_icap_set_bram(base_address, buffer_count, data[i]);
 281                 dirty = true;
 282
 283                 if (buffer_count < XHI_MAX_BUFFER_INTS - 1) {
 284                         buffer_count++;
 285                         continue;
 286                 }
 287
 288                 /* Write data to ICAP */
 289                 status = buffer_icap_device_write(
 290                                 drvdata,
 291                                 XHI_BUFFER_START,
 292                                 XHI_MAX_BUFFER_INTS);
 293                 if (status != 0) {
 294                         /* abort. */
 295                         buffer_icap_reset(drvdata);
 296                         return status;
 297                 }
 298
 299                 buffer_count = 0;
 300                 dirty = false;
 301         }
 302
 303         /* Write unwritten data to ICAP */
 304         if (dirty) {
 305                 /* Write data to ICAP */
 306                 status = buffer_icap_device_write(drvdata, XHI_BUFFER_START,
 307                                              buffer_count);
 308                 if (status != 0) {
 309                         /* abort. */
 310                         buffer_icap_reset(drvdata);
 311                 }
 312                 return status;
 313         }
 314
 315         return 0;
 316 };
 317
 318 /**
 319  * buffer_icap_get_configuration - Read configuration data from the device.
 320  * @drvdata: a pointer to the drvdata.
 321  * @data: Address of the data representing the partial bitstream
 322  * @size: the size of the partial bitstream in 32 bit words.
 323  **/
 324 int buffer_icap_get_configuration(struct hwicap_drvdata *drvdata, u32 *data,
 325                              u32 size)
 326 {
 327         int status;
 328         s32 buffer_count = 0;
 329         u32 i;
 330         void __iomem *base_address = drvdata->base_address;
 331
 332         /* Loop through all the data */
 333         for (i = 0, buffer_count = XHI_MAX_BUFFER_INTS; i < size; i++) {
 334                 if (buffer_count == XHI_MAX_BUFFER_INTS) {
 335                         u32 words_remaining = size - i;
 336                         u32 words_to_read =
 337                                 words_remaining <
 338                                 XHI_MAX_BUFFER_INTS ? words_remaining :
 339                                 XHI_MAX_BUFFER_INTS;
 340
 341                         /* Read data from ICAP */
 342                         status = buffer_icap_device_read(
 343                                         drvdata,
 344                                         XHI_BUFFER_START,
 345                                         words_to_read);
 346                         if (status != 0) {
 347                                 /* abort. */
 348                                 buffer_icap_reset(drvdata);
 349                                 return status;
 350                         }
 351
 352                         buffer_count = 0;
 353                 }
 354
 355                 /* Copy data from bram */
 356                 data[i] = buffer_icap_get_bram(base_address, buffer_count);
 357                 buffer_count++;
 358         }
 359
 360         return 0;
 361 };