drivers/ata/pata_at91.c

   1 /*
   2  * PATA driver for AT91SAM9260 Static Memory Controller
   3  * with CompactFlash interface in True IDE mode
   4  *
   5  * Copyright (C) 2009 Matyukevich Sergey
   6  *               2011 Igor Plyatov
   7  *
   8  * Based on:
   9  *      * generic platform driver by Paul Mundt: drivers/ata/pata_platform.c
  10  *      * pata_at32 driver by Kristoffer Nyborg Gregertsen
  11  *      * at91_ide driver by Stanislaw Gruszka
  12  *
  13  * This program is free software; you can redistribute it and/or modify it
  14  * under the terms of the GNU General Public License version 2
  15  * as published by the Free Software Foundation.
  16  *
  17  */
  18
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/blkdev.h>
  22 #include <linux/gfp.h>
  23 #include <scsi/scsi_host.h>
  24 #include <linux/ata.h>
  25 #include <linux/clk.h>
  26 #include <linux/libata.h>
  27 #include <linux/mfd/syscon.h>
  28 #include <linux/mfd/syscon/atmel-smc.h>
  29 #include <linux/platform_device.h>
  30 #include <linux/ata_platform.h>
  31 #include <linux/platform_data/atmel.h>
  32 #include <linux/regmap.h>
  33 #include <linux/gpio.h>
  34
  35 #define DRV_NAME                "pata_at91"
  36 #define DRV_VERSION             "0.3"
  37
  38 #define CF_IDE_OFFSET           0x00c00000
  39 #define CF_ALT_IDE_OFFSET       0x00e00000
  40 #define CF_IDE_RES_SIZE         0x08
  41 #define CS_PULSE_MAXIMUM        319
  42 #define ER_SMC_CALC             1
  43 #define ER_SMC_RECALC           2
  44
  45 struct at91_ide_info {
  46         unsigned long mode;
  47         unsigned int cs;
  48         struct clk *mck;
  49         void __iomem *ide_addr;
  50         void __iomem *alt_addr;
  51 };
  52
  53 /**
  54  * struct smc_range - range of valid values for SMC register.
  55  */
  56 struct smc_range {
  57         int min;
  58         int max;
  59 };
  60
  61 struct regmap *smc;
  62
  63 struct at91sam9_smc_generic_fields {
  64         struct regmap_field *setup;
  65         struct regmap_field *pulse;
  66         struct regmap_field *cycle;
  67         struct regmap_field *mode;
  68 } fields;
  69
  70 /**
  71  * adjust_smc_value - adjust value for one of SMC registers.
  72  * @value: adjusted value
  73  * @range: array of SMC ranges with valid values
  74  * @size: SMC ranges array size
  75  *
  76  * This returns the difference between input and output value or negative
  77  * in case of invalid input value.
  78  * If negative returned, then output value = maximal possible from ranges.
  79  */
  80 static int adjust_smc_value(int *value, struct smc_range *range, int size)
  81 {
  82         int maximum = (range + size - 1)->max;
  83         int remainder;
  84
  85         do {
  86                 if (*value < range->min) {
  87                         remainder = range->min - *value;
  88                         *value = range->min; /* nearest valid value */
  89                         return remainder;
  90                 } else if ((range->min <= *value) && (*value <= range->max))
  91                         return 0;
  92
  93                 range++;
  94         } while (--size);
  95         *value = maximum;
  96
  97         return -1; /* invalid value */
  98 }
  99
 100 /**
 101  * calc_smc_vals - calculate SMC register values
 102  * @dev: ATA device
 103  * @setup: SMC_SETUP register value
 104  * @pulse: SMC_PULSE register value
 105  * @cycle: SMC_CYCLE register value
 106  *
 107  * This returns negative in case of invalid values for SMC registers:
 108  * -ER_SMC_RECALC - recalculation required for SMC values,
 109  * -ER_SMC_CALC - calculation failed (invalid input values).
 110  *
 111  * SMC use special coding scheme, see "Coding and Range of Timing
 112  * Parameters" table from AT91SAM9 datasheets.
 113  *
 114  *      SMC_SETUP = 128*setup[5] + setup[4:0]
 115  *      SMC_PULSE = 256*pulse[6] + pulse[5:0]
 116  *      SMC_CYCLE = 256*cycle[8:7] + cycle[6:0]
 117  */
 118 static int calc_smc_vals(struct device *dev,
 119                 int *setup, int *pulse, int *cycle, int *cs_pulse)
 120 {
 121         int ret_val;
 122         int err = 0;
 123         struct smc_range range_setup[] = {      /* SMC_SETUP valid values */
 124                 {.min = 0,      .max = 31},     /* first  range */
 125                 {.min = 128,    .max = 159}     /* second range */
 126         };
 127         struct smc_range range_pulse[] = {      /* SMC_PULSE valid values */
 128                 {.min = 0,      .max = 63},     /* first  range */
 129                 {.min = 256,    .max = 319}     /* second range */
 130         };
 131         struct smc_range range_cycle[] = {      /* SMC_CYCLE valid values */
 132                 {.min = 0,      .max = 127},    /* first  range */
 133                 {.min = 256,    .max = 383},    /* second range */
 134                 {.min = 512,    .max = 639},    /* third  range */
 135                 {.min = 768,    .max = 895}     /* fourth range */
 136         };
 137
 138         ret_val = adjust_smc_value(setup, range_setup, ARRAY_SIZE(range_setup));
 139         if (ret_val < 0)
 140                 dev_warn(dev, "maximal SMC Setup value\n");
 141         else
 142                 *cycle += ret_val;
 143
 144         ret_val = adjust_smc_value(pulse, range_pulse, ARRAY_SIZE(range_pulse));
 145         if (ret_val < 0)
 146                 dev_warn(dev, "maximal SMC Pulse value\n");
 147         else
 148                 *cycle += ret_val;
 149
 150         ret_val = adjust_smc_value(cycle, range_cycle, ARRAY_SIZE(range_cycle));
 151         if (ret_val < 0)
 152                 dev_warn(dev, "maximal SMC Cycle value\n");
 153
 154         *cs_pulse = *cycle;
 155         if (*cs_pulse > CS_PULSE_MAXIMUM) {
 156                 dev_err(dev, "unable to calculate valid SMC settings\n");
 157                 return -ER_SMC_CALC;
 158         }
 159
 160         ret_val = adjust_smc_value(cs_pulse, range_pulse,
 161                                         ARRAY_SIZE(range_pulse));
 162         if (ret_val < 0) {
 163                 dev_warn(dev, "maximal SMC CS Pulse value\n");
 164         } else if (ret_val != 0) {
 165                 *cycle = *cs_pulse;
 166                 dev_warn(dev, "SMC Cycle extended\n");
 167                 err = -ER_SMC_RECALC;
 168         }
 169
 170         return err;
 171 }
 172
 173 /**
 174  * to_smc_format - convert values into SMC format
 175  * @setup: SETUP value of SMC Setup Register
 176  * @pulse: PULSE value of SMC Pulse Register
 177  * @cycle: CYCLE value of SMC Cycle Register
 178  * @cs_pulse: NCS_PULSE value of SMC Pulse Register
 179  */
 180 static void to_smc_format(int *setup, int *pulse, int *cycle, int *cs_pulse)
 181 {
 182         *setup = (*setup & 0x1f) | ((*setup & 0x80) >> 2);
 183         *pulse = (*pulse & 0x3f) | ((*pulse & 0x100) >> 2);
 184         *cycle = (*cycle & 0x7f) | ((*cycle & 0x300) >> 1);
 185         *cs_pulse = (*cs_pulse & 0x3f) | ((*cs_pulse & 0x100) >> 2);
 186 }
 187
 188 static unsigned long calc_mck_cycles(unsigned long ns, unsigned long mck_hz)
 189 {
 190         unsigned long mul;
 191
 192         /*
 193         * cycles = x [nsec] * f [Hz] / 10^9 [ns in sec] =
 194         *     x * (f / 1_000_000_000) =
 195         *     x * ((f * 65536) / 1_000_000_000) / 65536 =
 196         *     x * (((f / 10_000) * 65536) / 100_000) / 65536 =
 197         */
 198
 199         mul = (mck_hz / 10000) << 16;
 200         mul /= 100000;
 201
 202         return (ns * mul + 65536) >> 16;    /* rounding */
 203 }
 204
 205 /**
 206  * set_smc_timing - SMC timings setup.
 207  * @dev: device
 208  * @info: AT91 IDE info
 209  * @ata: ATA timings
 210  *
 211  * Its assumed that write timings are same as read timings,
 212  * cs_setup = 0 and cs_pulse = cycle.
 213  */
 214 static void set_smc_timing(struct device *dev, struct ata_device *adev,
 215                 struct at91_ide_info *info, const struct ata_timing *ata)
 216 {
 217         int ret = 0;
 218         int use_iordy;
 219         unsigned int t6z;         /* data tristate time in ns */
 220         unsigned int cycle;       /* SMC Cycle width in MCK ticks */
 221         unsigned int setup;       /* SMC Setup width in MCK ticks */
 222         unsigned int pulse;       /* CFIOR and CFIOW pulse width in MCK ticks */
 223         unsigned int cs_pulse;    /* CS4 or CS5 pulse width in MCK ticks*/
 224         unsigned int tdf_cycles;  /* SMC TDF MCK ticks */
 225         unsigned long mck_hz;     /* MCK frequency in Hz */
 226
 227         t6z = (ata->mode < XFER_PIO_5) ? 30 : 20;
 228         mck_hz = clk_get_rate(info->mck);
 229         cycle = calc_mck_cycles(ata->cyc8b, mck_hz);
 230         setup = calc_mck_cycles(ata->setup, mck_hz);
 231         pulse = calc_mck_cycles(ata->act8b, mck_hz);
 232         tdf_cycles = calc_mck_cycles(t6z, mck_hz);
 233
 234         do {
 235                 ret = calc_smc_vals(dev, &setup, &pulse, &cycle, &cs_pulse);
 236         } while (ret == -ER_SMC_RECALC);
 237
 238         if (ret == -ER_SMC_CALC)
 239                 dev_err(dev, "Interface may not operate correctly\n");
 240
 241         dev_dbg(dev, "SMC Setup=%u, Pulse=%u, Cycle=%u, CS Pulse=%u\n",
 242                 setup, pulse, cycle, cs_pulse);
 243         to_smc_format(&setup, &pulse, &cycle, &cs_pulse);
 244         /* disable or enable waiting for IORDY signal */
 245         use_iordy = ata_pio_need_iordy(adev);
 246         if (use_iordy)
 247                 info->mode |= AT91_SMC_EXNWMODE_READY;
 248
 249         if (tdf_cycles > 15) {
 250                 tdf_cycles = 15;
 251                 dev_warn(dev, "maximal SMC TDF Cycles value\n");
 252         }
 253
 254         dev_dbg(dev, "Use IORDY=%u, TDF Cycles=%u\n", use_iordy, tdf_cycles);
 255
 256         regmap_fields_write(fields.setup, info->cs,
 257                             AT91SAM9_SMC_NRDSETUP(setup) |
 258                             AT91SAM9_SMC_NWESETUP(setup) |
 259                             AT91SAM9_SMC_NCS_NRDSETUP(0) |
 260                             AT91SAM9_SMC_NCS_WRSETUP(0));
 261         regmap_fields_write(fields.pulse, info->cs,
 262                             AT91SAM9_SMC_NRDPULSE(pulse) |
 263                             AT91SAM9_SMC_NWEPULSE(pulse) |
 264                             AT91SAM9_SMC_NCS_NRDPULSE(cs_pulse) |
 265                             AT91SAM9_SMC_NCS_WRPULSE(cs_pulse));
 266         regmap_fields_write(fields.cycle, info->cs,
 267                             AT91SAM9_SMC_NRDCYCLE(cycle) |
 268                             AT91SAM9_SMC_NWECYCLE(cycle));
 269         regmap_fields_write(fields.mode, info->cs, info->mode |
 270                             AT91_SMC_TDF_(tdf_cycles));
 271 }
 272
 273 static void pata_at91_set_piomode(struct ata_port *ap, struct ata_device *adev)
 274 {
 275         struct at91_ide_info *info = ap->host->private_data;
 276         struct ata_timing timing;
 277         int ret;
 278
 279         /* Compute ATA timing and set it to SMC */
 280         ret = ata_timing_compute(adev, adev->pio_mode, &timing, 1000, 0);
 281         if (ret) {
 282                 dev_warn(ap->dev, "Failed to compute ATA timing %d, "
 283                          "set PIO_0 timing\n", ret);
 284                 timing = *ata_timing_find_mode(XFER_PIO_0);
 285         }
 286         set_smc_timing(ap->dev, adev, info, &timing);
 287 }
 288
 289 static unsigned int pata_at91_data_xfer_noirq(struct ata_device *dev,
 290                 unsigned char *buf, unsigned int buflen, int rw)
 291 {
 292         struct at91_ide_info *info = dev->link->ap->host->private_data;
 293         unsigned int consumed;
 294         unsigned int mode;
 295         unsigned long flags;
 296
 297         local_irq_save(flags);
 298         regmap_fields_read(fields.mode, info->cs, &mode);
 299
 300         /* set 16bit mode before writing data */
 301         regmap_fields_write(fields.mode, info->cs, (mode & ~AT91_SMC_DBW) |
 302                             AT91_SMC_DBW_16);
 303
 304         consumed = ata_sff_data_xfer(dev, buf, buflen, rw);
 305
 306         /* restore 8bit mode after data is written */
 307         regmap_fields_write(fields.mode, info->cs, (mode & ~AT91_SMC_DBW) |
 308                             AT91_SMC_DBW_8);
 309
 310         local_irq_restore(flags);
 311         return consumed;
 312 }
 313
 314 static struct scsi_host_template pata_at91_sht = {
 315         ATA_PIO_SHT(DRV_NAME),
 316 };
 317
 318 static struct ata_port_operations pata_at91_port_ops = {
 319         .inherits       = &ata_sff_port_ops,
 320
 321         .sff_data_xfer  = pata_at91_data_xfer_noirq,
 322         .set_piomode    = pata_at91_set_piomode,
 323         .cable_detect   = ata_cable_40wire,
 324 };
 325
 326 static int at91sam9_smc_fields_init(struct device *dev)
 327 {
 328         struct reg_field field = REG_FIELD(0, 0, 31);
 329
 330         field.id_size = 8;
 331         field.id_offset = AT91SAM9_SMC_GENERIC_BLK_SZ;
 332
 333         field.reg = AT91SAM9_SMC_SETUP(AT91SAM9_SMC_GENERIC);
 334         fields.setup = devm_regmap_field_alloc(dev, smc, field);
 335         if (IS_ERR(fields.setup))
 336                 return PTR_ERR(fields.setup);
 337
 338         field.reg = AT91SAM9_SMC_PULSE(AT91SAM9_SMC_GENERIC);
 339         fields.pulse = devm_regmap_field_alloc(dev, smc, field);
 340         if (IS_ERR(fields.pulse))
 341                 return PTR_ERR(fields.pulse);
 342
 343         field.reg = AT91SAM9_SMC_CYCLE(AT91SAM9_SMC_GENERIC);
 344         fields.cycle = devm_regmap_field_alloc(dev, smc, field);
 345         if (IS_ERR(fields.cycle))
 346                 return PTR_ERR(fields.cycle);
 347
 348         field.reg = AT91SAM9_SMC_MODE(AT91SAM9_SMC_GENERIC);
 349         fields.mode = devm_regmap_field_alloc(dev, smc, field);
 350
 351         return PTR_ERR_OR_ZERO(fields.mode);
 352 }
 353
 354 static int pata_at91_probe(struct platform_device *pdev)
 355 {
 356         struct at91_cf_data *board = dev_get_platdata(&pdev->dev);
 357         struct device *dev = &pdev->dev;
 358         struct at91_ide_info *info;
 359         struct resource *mem_res;
 360         struct ata_host *host;
 361         struct ata_port *ap;
 362
 363         int irq_flags = 0;
 364         int irq = 0;
 365         int ret;
 366
 367         /*  get platform resources: IO/CTL memories and irq/rst pins */
 368
 369         if (pdev->num_resources != 1) {
 370                 dev_err(&pdev->dev, "invalid number of resources\n");
 371                 return -EINVAL;
 372         }
 373
 374         mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 375
 376         if (!mem_res) {
 377                 dev_err(dev, "failed to get mem resource\n");
 378                 return -EINVAL;
 379         }
 380
 381         irq = board->irq_pin;
 382
 383         smc = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "atmel,smc");
 384         if (IS_ERR(smc))
 385                 return PTR_ERR(smc);
 386
 387         ret = at91sam9_smc_fields_init(dev);
 388         if (ret < 0)
 389                 return ret;
 390
 391         /* init ata host */
 392
 393         host = ata_host_alloc(dev, 1);
 394
 395         if (!host)
 396                 return -ENOMEM;
 397
 398         ap = host->ports[0];
 399         ap->ops = &pata_at91_port_ops;
 400         ap->flags |= ATA_FLAG_SLAVE_POSS;
 401         ap->pio_mask = ATA_PIO4;
 402
 403         if (!gpio_is_valid(irq)) {
 404                 ap->flags |= ATA_FLAG_PIO_POLLING;
 405                 ata_port_desc(ap, "no IRQ, using PIO polling");
 406         }
 407
 408         info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
 409
 410         if (!info) {
 411                 dev_err(dev, "failed to allocate memory for private data\n");
 412                 return -ENOMEM;
 413         }
 414
 415         info->mck = clk_get(NULL, "mck");
 416
 417         if (IS_ERR(info->mck)) {
 418                 dev_err(dev, "failed to get access to mck clock\n");
 419                 return -ENODEV;
 420         }
 421
 422         info->cs    = board->chipselect;
 423         info->mode  = AT91_SMC_READMODE | AT91_SMC_WRITEMODE |
 424                 AT91_SMC_EXNWMODE_READY | AT91_SMC_BAT_SELECT |
 425                 AT91_SMC_DBW_8 | AT91_SMC_TDF_(0);
 426
 427         info->ide_addr = devm_ioremap(dev,
 428                         mem_res->start + CF_IDE_OFFSET, CF_IDE_RES_SIZE);
 429
 430         if (!info->ide_addr) {
 431                 dev_err(dev, "failed to map IO base\n");
 432                 ret = -ENOMEM;
 433                 goto err_put;
 434         }
 435
 436         info->alt_addr = devm_ioremap(dev,
 437                         mem_res->start + CF_ALT_IDE_OFFSET, CF_IDE_RES_SIZE);
 438
 439         if (!info->alt_addr) {
 440                 dev_err(dev, "failed to map CTL base\n");
 441                 ret = -ENOMEM;
 442                 goto err_put;
 443         }
 444
 445         ap->ioaddr.cmd_addr = info->ide_addr;
 446         ap->ioaddr.ctl_addr = info->alt_addr + 0x06;
 447         ap->ioaddr.altstatus_addr = ap->ioaddr.ctl_addr;
 448
 449         ata_sff_std_ports(&ap->ioaddr);
 450
 451         ata_port_desc(ap, "mmio cmd 0x%llx ctl 0x%llx",
 452                         (unsigned long long)mem_res->start + CF_IDE_OFFSET,
 453                         (unsigned long long)mem_res->start + CF_ALT_IDE_OFFSET);
 454
 455         host->private_data = info;
 456
 457         ret = ata_host_activate(host, gpio_is_valid(irq) ? gpio_to_irq(irq) : 0,
 458                                 gpio_is_valid(irq) ? ata_sff_interrupt : NULL,
 459                                 irq_flags, &pata_at91_sht);
 460         if (ret)
 461                 goto err_put;
 462
 463         return 0;
 464
 465 err_put:
 466         clk_put(info->mck);
 467         return ret;
 468 }
 469
 470 static int pata_at91_remove(struct platform_device *pdev)
 471 {
 472         struct ata_host *host = platform_get_drvdata(pdev);
 473         struct at91_ide_info *info;
 474
 475         if (!host)
 476                 return 0;
 477         info = host->private_data;
 478
 479         ata_host_detach(host);
 480
 481         if (!info)
 482                 return 0;
 483
 484         clk_put(info->mck);
 485
 486         return 0;
 487 }
 488
 489 static struct platform_driver pata_at91_driver = {
 490         .probe          = pata_at91_probe,
 491         .remove         = pata_at91_remove,
 492         .driver         = {
 493                 .name           = DRV_NAME,
 494         },
 495 };
 496
 497 module_platform_driver(pata_at91_driver);
 498
 499 MODULE_LICENSE("GPL");
 500 MODULE_DESCRIPTION("Driver for CF in True IDE mode on AT91SAM9260 SoC");
 501 MODULE_AUTHOR("Matyukevich Sergey");
 502 MODULE_VERSION(DRV_VERSION);
 503