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
  34 #include <asm/gpio.h>
  35
  36 #define DRV_NAME                "pata_at91"
  37 #define DRV_VERSION             "0.3"
  38
  39 #define CF_IDE_OFFSET           0x00c00000
  40 #define CF_ALT_IDE_OFFSET       0x00e00000
  41 #define CF_IDE_RES_SIZE         0x08
  42 #define CS_PULSE_MAXIMUM        319
  43 #define ER_SMC_CALC             1
  44 #define ER_SMC_RECALC           2
  45
  46 struct at91_ide_info {
  47         unsigned long mode;
  48         unsigned int cs;
  49         struct clk *mck;
  50         void __iomem *ide_addr;
  51         void __iomem *alt_addr;
  52 };
  53
  54 /**
  55  * struct smc_range - range of valid values for SMC register.
  56  */
  57 struct smc_range {
  58         int min;
  59         int max;
  60 };
  61
  62 struct regmap *smc;
  63
  64 struct at91sam9_smc_generic_fields {
  65         struct regmap_field *setup;
  66         struct regmap_field *pulse;
  67         struct regmap_field *cycle;
  68         struct regmap_field *mode;
  69 } fields;
  70
  71 /**
  72  * adjust_smc_value - adjust value for one of SMC registers.
  73  * @value: adjusted value
  74  * @range: array of SMC ranges with valid values
  75  * @size: SMC ranges array size
  76  *
  77  * This returns the difference between input and output value or negative
  78  * in case of invalid input value.
  79  * If negative returned, then output value = maximal possible from ranges.
  80  */
  81 static int adjust_smc_value(int *value, struct smc_range *range, int size)
  82 {
  83         int maximum = (range + size - 1)->max;
  84         int remainder;
  85
  86         do {
  87                 if (*value < range->min) {
  88                         remainder = range->min - *value;
  89                         *value = range->min; /* nearest valid value */
  90                         return remainder;
  91                 } else if ((range->min <= *value) && (*value <= range->max))
  92                         return 0;
  93
  94                 range++;
  95         } while (--size);
  96         *value = maximum;
  97
  98         return -1; /* invalid value */
  99 }
 100
 101 /**
 102  * calc_smc_vals - calculate SMC register values
 103  * @dev: ATA device
 104  * @setup: SMC_SETUP register value
 105  * @pulse: SMC_PULSE register value
 106  * @cycle: SMC_CYCLE register value
 107  *
 108  * This returns negative in case of invalid values for SMC registers:
 109  * -ER_SMC_RECALC - recalculation required for SMC values,
 110  * -ER_SMC_CALC - calculation failed (invalid input values).
 111  *
 112  * SMC use special coding scheme, see "Coding and Range of Timing
 113  * Parameters" table from AT91SAM9 datasheets.
 114  *
 115  *      SMC_SETUP = 128*setup[5] + setup[4:0]
 116  *      SMC_PULSE = 256*pulse[6] + pulse[5:0]
 117  *      SMC_CYCLE = 256*cycle[8:7] + cycle[6:0]
 118  */
 119 static int calc_smc_vals(struct device *dev,
 120                 int *setup, int *pulse, int *cycle, int *cs_pulse)
 121 {
 122         int ret_val;
 123         int err = 0;
 124         struct smc_range range_setup[] = {      /* SMC_SETUP valid values */
 125                 {.min = 0,      .max = 31},     /* first  range */
 126                 {.min = 128,    .max = 159}     /* second range */
 127         };
 128         struct smc_range range_pulse[] = {      /* SMC_PULSE valid values */
 129                 {.min = 0,      .max = 63},     /* first  range */
 130                 {.min = 256,    .max = 319}     /* second range */
 131         };
 132         struct smc_range range_cycle[] = {      /* SMC_CYCLE valid values */
 133                 {.min = 0,      .max = 127},    /* first  range */
 134                 {.min = 256,    .max = 383},    /* second range */
 135                 {.min = 512,    .max = 639},    /* third  range */
 136                 {.min = 768,    .max = 895}     /* fourth range */
 137         };
 138
 139         ret_val = adjust_smc_value(setup, range_setup, ARRAY_SIZE(range_setup));
 140         if (ret_val < 0)
 141                 dev_warn(dev, "maximal SMC Setup value\n");
 142         else
 143                 *cycle += ret_val;
 144
 145         ret_val = adjust_smc_value(pulse, range_pulse, ARRAY_SIZE(range_pulse));
 146         if (ret_val < 0)
 147                 dev_warn(dev, "maximal SMC Pulse value\n");
 148         else
 149                 *cycle += ret_val;
 150
 151         ret_val = adjust_smc_value(cycle, range_cycle, ARRAY_SIZE(range_cycle));
 152         if (ret_val < 0)
 153                 dev_warn(dev, "maximal SMC Cycle value\n");
 154
 155         *cs_pulse = *cycle;
 156         if (*cs_pulse > CS_PULSE_MAXIMUM) {
 157                 dev_err(dev, "unable to calculate valid SMC settings\n");
 158                 return -ER_SMC_CALC;
 159         }
 160
 161         ret_val = adjust_smc_value(cs_pulse, range_pulse,
 162                                         ARRAY_SIZE(range_pulse));
 163         if (ret_val < 0) {
 164                 dev_warn(dev, "maximal SMC CS Pulse value\n");
 165         } else if (ret_val != 0) {
 166                 *cycle = *cs_pulse;
 167                 dev_warn(dev, "SMC Cycle extended\n");
 168                 err = -ER_SMC_RECALC;
 169         }
 170
 171         return err;
 172 }
 173
 174 /**
 175  * to_smc_format - convert values into SMC format
 176  * @setup: SETUP value of SMC Setup Register
 177  * @pulse: PULSE value of SMC Pulse Register
 178  * @cycle: CYCLE value of SMC Cycle Register
 179  * @cs_pulse: NCS_PULSE value of SMC Pulse Register
 180  */
 181 static void to_smc_format(int *setup, int *pulse, int *cycle, int *cs_pulse)
 182 {
 183         *setup = (*setup & 0x1f) | ((*setup & 0x80) >> 2);
 184         *pulse = (*pulse & 0x3f) | ((*pulse & 0x100) >> 2);
 185         *cycle = (*cycle & 0x7f) | ((*cycle & 0x300) >> 1);
 186         *cs_pulse = (*cs_pulse & 0x3f) | ((*cs_pulse & 0x100) >> 2);
 187 }
 188
 189 static unsigned long calc_mck_cycles(unsigned long ns, unsigned long mck_hz)
 190 {
 191         unsigned long mul;
 192
 193         /*
 194         * cycles = x [nsec] * f [Hz] / 10^9 [ns in sec] =
 195         *     x * (f / 1_000_000_000) =
 196         *     x * ((f * 65536) / 1_000_000_000) / 65536 =
 197         *     x * (((f / 10_000) * 65536) / 100_000) / 65536 =
 198         */
 199
 200         mul = (mck_hz / 10000) << 16;
 201         mul /= 100000;
 202
 203         return (ns * mul + 65536) >> 16;    /* rounding */
 204 }
 205
 206 /**
 207  * set_smc_timing - SMC timings setup.
 208  * @dev: device
 209  * @info: AT91 IDE info
 210  * @ata: ATA timings
 211  *
 212  * Its assumed that write timings are same as read timings,
 213  * cs_setup = 0 and cs_pulse = cycle.
 214  */
 215 static void set_smc_timing(struct device *dev, struct ata_device *adev,
 216                 struct at91_ide_info *info, const struct ata_timing *ata)
 217 {
 218         int ret = 0;
 219         int use_iordy;
 220         unsigned int t6z;         /* data tristate time in ns */
 221         unsigned int cycle;       /* SMC Cycle width in MCK ticks */
 222         unsigned int setup;       /* SMC Setup width in MCK ticks */
 223         unsigned int pulse;       /* CFIOR and CFIOW pulse width in MCK ticks */
 224         unsigned int cs_pulse;    /* CS4 or CS5 pulse width in MCK ticks*/
 225         unsigned int tdf_cycles;  /* SMC TDF MCK ticks */
 226         unsigned long mck_hz;     /* MCK frequency in Hz */
 227
 228         t6z = (ata->mode < XFER_PIO_5) ? 30 : 20;
 229         mck_hz = clk_get_rate(info->mck);
 230         cycle = calc_mck_cycles(ata->cyc8b, mck_hz);
 231         setup = calc_mck_cycles(ata->setup, mck_hz);
 232         pulse = calc_mck_cycles(ata->act8b, mck_hz);
 233         tdf_cycles = calc_mck_cycles(t6z, mck_hz);
 234
 235         do {
 236                 ret = calc_smc_vals(dev, &setup, &pulse, &cycle, &cs_pulse);
 237         } while (ret == -ER_SMC_RECALC);
 238
 239         if (ret == -ER_SMC_CALC)
 240                 dev_err(dev, "Interface may not operate correctly\n");
 241
 242         dev_dbg(dev, "SMC Setup=%u, Pulse=%u, Cycle=%u, CS Pulse=%u\n",
 243                 setup, pulse, cycle, cs_pulse);
 244         to_smc_format(&setup, &pulse, &cycle, &cs_pulse);
 245         /* disable or enable waiting for IORDY signal */
 246         use_iordy = ata_pio_need_iordy(adev);
 247         if (use_iordy)
 248                 info->mode |= AT91_SMC_EXNWMODE_READY;
 249
 250         if (tdf_cycles > 15) {
 251                 tdf_cycles = 15;
 252                 dev_warn(dev, "maximal SMC TDF Cycles value\n");
 253         }
 254
 255         dev_dbg(dev, "Use IORDY=%u, TDF Cycles=%u\n", use_iordy, tdf_cycles);
 256
 257         regmap_fields_write(fields.setup, info->cs,
 258                             AT91SAM9_SMC_NRDSETUP(setup) |
 259                             AT91SAM9_SMC_NWESETUP(setup) |
 260                             AT91SAM9_SMC_NCS_NRDSETUP(0) |
 261                             AT91SAM9_SMC_NCS_WRSETUP(0));
 262         regmap_fields_write(fields.pulse, info->cs,
 263                             AT91SAM9_SMC_NRDPULSE(pulse) |
 264                             AT91SAM9_SMC_NWEPULSE(pulse) |
 265                             AT91SAM9_SMC_NCS_NRDPULSE(cs_pulse) |
 266                             AT91SAM9_SMC_NCS_WRPULSE(cs_pulse));
 267         regmap_fields_write(fields.cycle, info->cs,
 268                             AT91SAM9_SMC_NRDCYCLE(cycle) |
 269                             AT91SAM9_SMC_NWECYCLE(cycle));
 270         regmap_fields_write(fields.mode, info->cs, info->mode |
 271                             AT91_SMC_TDF_(tdf_cycles));
 272 }
 273
 274 static void pata_at91_set_piomode(struct ata_port *ap, struct ata_device *adev)
 275 {
 276         struct at91_ide_info *info = ap->host->private_data;
 277         struct ata_timing timing;
 278         int ret;
 279
 280         /* Compute ATA timing and set it to SMC */
 281         ret = ata_timing_compute(adev, adev->pio_mode, &timing, 1000, 0);
 282         if (ret) {
 283                 dev_warn(ap->dev, "Failed to compute ATA timing %d, "
 284                          "set PIO_0 timing\n", ret);
 285                 timing = *ata_timing_find_mode(XFER_PIO_0);
 286         }
 287         set_smc_timing(ap->dev, adev, info, &timing);
 288 }
 289
 290 static unsigned int pata_at91_data_xfer_noirq(struct ata_device *dev,
 291                 unsigned char *buf, unsigned int buflen, int rw)
 292 {
 293         struct at91_ide_info *info = dev->link->ap->host->private_data;
 294         unsigned int consumed;
 295         unsigned int mode;
 296         unsigned long flags;
 297
 298         local_irq_save(flags);
 299         regmap_fields_read(fields.mode, info->cs, &mode);
 300
 301         /* set 16bit mode before writing data */
 302         regmap_fields_write(fields.mode, info->cs, (mode & ~AT91_SMC_DBW) |
 303                             AT91_SMC_DBW_16);
 304
 305         consumed = ata_sff_data_xfer(dev, buf, buflen, rw);
 306
 307         /* restore 8bit mode after data is written */
 308         regmap_fields_write(fields.mode, info->cs, (mode & ~AT91_SMC_DBW) |
 309                             AT91_SMC_DBW_8);
 310
 311         local_irq_restore(flags);
 312         return consumed;
 313 }
 314
 315 static struct scsi_host_template pata_at91_sht = {
 316         ATA_PIO_SHT(DRV_NAME),
 317 };
 318
 319 static struct ata_port_operations pata_at91_port_ops = {
 320         .inherits       = &ata_sff_port_ops,
 321
 322         .sff_data_xfer  = pata_at91_data_xfer_noirq,
 323         .set_piomode    = pata_at91_set_piomode,
 324         .cable_detect   = ata_cable_40wire,
 325 };
 326
 327 static int at91sam9_smc_fields_init(struct device *dev)
 328 {
 329         struct reg_field field = REG_FIELD(0, 0, 31);
 330
 331         field.id_size = 8;
 332         field.id_offset = AT91SAM9_SMC_GENERIC_BLK_SZ;
 333
 334         field.reg = AT91SAM9_SMC_SETUP(AT91SAM9_SMC_GENERIC);
 335         fields.setup = devm_regmap_field_alloc(dev, smc, field);
 336         if (IS_ERR(fields.setup))
 337                 return PTR_ERR(fields.setup);
 338
 339         field.reg = AT91SAM9_SMC_PULSE(AT91SAM9_SMC_GENERIC);
 340         fields.pulse = devm_regmap_field_alloc(dev, smc, field);
 341         if (IS_ERR(fields.pulse))
 342                 return PTR_ERR(fields.pulse);
 343
 344         field.reg = AT91SAM9_SMC_CYCLE(AT91SAM9_SMC_GENERIC);
 345         fields.cycle = devm_regmap_field_alloc(dev, smc, field);
 346         if (IS_ERR(fields.cycle))
 347                 return PTR_ERR(fields.cycle);
 348
 349         field.reg = AT91SAM9_SMC_MODE(AT91SAM9_SMC_GENERIC);
 350         fields.mode = devm_regmap_field_alloc(dev, smc, field);
 351         if (IS_ERR(fields.mode))
 352                 return PTR_ERR(fields.mode);
 353
 354         return 0;
 355 }
 356
 357 static int pata_at91_probe(struct platform_device *pdev)
 358 {
 359         struct at91_cf_data *board = dev_get_platdata(&pdev->dev);
 360         struct device *dev = &pdev->dev;
 361         struct at91_ide_info *info;
 362         struct resource *mem_res;
 363         struct ata_host *host;
 364         struct ata_port *ap;
 365
 366         int irq_flags = 0;
 367         int irq = 0;
 368         int ret;
 369
 370         /*  get platform resources: IO/CTL memories and irq/rst pins */
 371
 372         if (pdev->num_resources != 1) {
 373                 dev_err(&pdev->dev, "invalid number of resources\n");
 374                 return -EINVAL;
 375         }
 376
 377         mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 378
 379         if (!mem_res) {
 380                 dev_err(dev, "failed to get mem resource\n");
 381                 return -EINVAL;
 382         }
 383
 384         irq = board->irq_pin;
 385
 386         smc = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "atmel,smc");
 387         if (IS_ERR(smc))
 388                 return PTR_ERR(smc);
 389
 390         ret = at91sam9_smc_fields_init(dev);
 391         if (ret < 0)
 392                 return ret;
 393
 394         /* init ata host */
 395
 396         host = ata_host_alloc(dev, 1);
 397
 398         if (!host)
 399                 return -ENOMEM;
 400
 401         ap = host->ports[0];
 402         ap->ops = &pata_at91_port_ops;
 403         ap->flags |= ATA_FLAG_SLAVE_POSS;
 404         ap->pio_mask = ATA_PIO4;
 405
 406         if (!gpio_is_valid(irq)) {
 407                 ap->flags |= ATA_FLAG_PIO_POLLING;
 408                 ata_port_desc(ap, "no IRQ, using PIO polling");
 409         }
 410
 411         info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
 412
 413         if (!info) {
 414                 dev_err(dev, "failed to allocate memory for private data\n");
 415                 return -ENOMEM;
 416         }
 417
 418         info->mck = clk_get(NULL, "mck");
 419
 420         if (IS_ERR(info->mck)) {
 421                 dev_err(dev, "failed to get access to mck clock\n");
 422                 return -ENODEV;
 423         }
 424
 425         info->cs    = board->chipselect;
 426         info->mode  = AT91_SMC_READMODE | AT91_SMC_WRITEMODE |
 427                 AT91_SMC_EXNWMODE_READY | AT91_SMC_BAT_SELECT |
 428                 AT91_SMC_DBW_8 | AT91_SMC_TDF_(0);
 429
 430         info->ide_addr = devm_ioremap(dev,
 431                         mem_res->start + CF_IDE_OFFSET, CF_IDE_RES_SIZE);
 432
 433         if (!info->ide_addr) {
 434                 dev_err(dev, "failed to map IO base\n");
 435                 ret = -ENOMEM;
 436                 goto err_put;
 437         }
 438
 439         info->alt_addr = devm_ioremap(dev,
 440                         mem_res->start + CF_ALT_IDE_OFFSET, CF_IDE_RES_SIZE);
 441
 442         if (!info->alt_addr) {
 443                 dev_err(dev, "failed to map CTL base\n");
 444                 ret = -ENOMEM;
 445                 goto err_put;
 446         }
 447
 448         ap->ioaddr.cmd_addr = info->ide_addr;
 449         ap->ioaddr.ctl_addr = info->alt_addr + 0x06;
 450         ap->ioaddr.altstatus_addr = ap->ioaddr.ctl_addr;
 451
 452         ata_sff_std_ports(&ap->ioaddr);
 453
 454         ata_port_desc(ap, "mmio cmd 0x%llx ctl 0x%llx",
 455                         (unsigned long long)mem_res->start + CF_IDE_OFFSET,
 456                         (unsigned long long)mem_res->start + CF_ALT_IDE_OFFSET);
 457
 458         host->private_data = info;
 459
 460         ret = ata_host_activate(host, gpio_is_valid(irq) ? gpio_to_irq(irq) : 0,
 461                                 gpio_is_valid(irq) ? ata_sff_interrupt : NULL,
 462                                 irq_flags, &pata_at91_sht);
 463         if (ret)
 464                 goto err_put;
 465
 466         return 0;
 467
 468 err_put:
 469         clk_put(info->mck);
 470         return ret;
 471 }
 472
 473 static int pata_at91_remove(struct platform_device *pdev)
 474 {
 475         struct ata_host *host = platform_get_drvdata(pdev);
 476         struct at91_ide_info *info;
 477
 478         if (!host)
 479                 return 0;
 480         info = host->private_data;
 481
 482         ata_host_detach(host);
 483
 484         if (!info)
 485                 return 0;
 486
 487         clk_put(info->mck);
 488
 489         return 0;
 490 }
 491
 492 static struct platform_driver pata_at91_driver = {
 493         .probe          = pata_at91_probe,
 494         .remove         = pata_at91_remove,
 495         .driver         = {
 496                 .name           = DRV_NAME,
 497         },
 498 };
 499
 500 module_platform_driver(pata_at91_driver);
 501
 502 MODULE_LICENSE("GPL");
 503 MODULE_DESCRIPTION("Driver for CF in True IDE mode on AT91SAM9260 SoC");
 504 MODULE_AUTHOR("Matyukevich Sergey");
 505 MODULE_VERSION(DRV_VERSION);
 506