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  *
   7  * Based on:
   8  *      * generic platform driver by Paul Mundt: drivers/ata/pata_platform.c
   9  *      * pata_at32 driver by Kristoffer Nyborg Gregertsen
  10  *      * at91_ide driver by Stanislaw Gruszka
  11  *
  12  * This program is free software; you can redistribute it and/or modify it
  13  * under the terms of the GNU General Public License version 2
  14  * as published by the Free Software Foundation.
  15  *
  16  */
  17
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/init.h>
  21 #include <linux/blkdev.h>
  22 #include <scsi/scsi_host.h>
  23 #include <linux/ata.h>
  24 #include <linux/clk.h>
  25 #include <linux/libata.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/ata_platform.h>
  28
  29 #include <mach/at91sam9_smc.h>
  30 #include <mach/board.h>
  31 #include <mach/gpio.h>
  32
  33
  34 #define DRV_NAME "pata_at91"
  35 #define DRV_VERSION "0.1"
  36
  37 #define CF_IDE_OFFSET       0x00c00000
  38 #define CF_ALT_IDE_OFFSET   0x00e00000
  39 #define CF_IDE_RES_SIZE     0x08
  40
  41 struct at91_ide_info {
  42         unsigned long mode;
  43         unsigned int cs;
  44
  45         struct clk *mck;
  46
  47         void __iomem *ide_addr;
  48         void __iomem *alt_addr;
  49 };
  50
  51 static const struct ata_timing initial_timing =
  52         {XFER_PIO_0, 70, 290, 240, 600, 165, 150, 600, 0};
  53
  54 static unsigned long calc_mck_cycles(unsigned long ns, unsigned long mck_hz)
  55 {
  56         unsigned long mul;
  57
  58         /*
  59         * cycles = x [nsec] * f [Hz] / 10^9 [ns in sec] =
  60         *     x * (f / 1_000_000_000) =
  61         *     x * ((f * 65536) / 1_000_000_000) / 65536 =
  62         *     x * (((f / 10_000) * 65536) / 100_000) / 65536 =
  63         */
  64
  65         mul = (mck_hz / 10000) << 16;
  66         mul /= 100000;
  67
  68         return (ns * mul + 65536) >> 16;    /* rounding */
  69 }
  70
  71 static void set_smc_mode(struct at91_ide_info *info)
  72 {
  73         at91_sys_write(AT91_SMC_MODE(info->cs), info->mode);
  74         return;
  75 }
  76
  77 static void set_smc_timing(struct device *dev,
  78                 struct at91_ide_info *info, const struct ata_timing *ata)
  79 {
  80         unsigned long read_cycle, write_cycle, active, recover;
  81         unsigned long nrd_setup, nrd_pulse, nrd_recover;
  82         unsigned long nwe_setup, nwe_pulse;
  83
  84         unsigned long ncs_write_setup, ncs_write_pulse;
  85         unsigned long ncs_read_setup, ncs_read_pulse;
  86
  87         unsigned long mck_hz;
  88
  89         read_cycle  = ata->cyc8b;
  90         nrd_setup   = ata->setup;
  91         nrd_pulse   = ata->act8b;
  92         nrd_recover = ata->rec8b;
  93
  94         mck_hz = clk_get_rate(info->mck);
  95
  96         read_cycle  = calc_mck_cycles(read_cycle, mck_hz);
  97         nrd_setup   = calc_mck_cycles(nrd_setup, mck_hz);
  98         nrd_pulse   = calc_mck_cycles(nrd_pulse, mck_hz);
  99         nrd_recover = calc_mck_cycles(nrd_recover, mck_hz);
 100
 101         active  = nrd_setup + nrd_pulse;
 102         recover = read_cycle - active;
 103
 104         /* Need at least two cycles recovery */
 105         if (recover < 2)
 106                 read_cycle = active + 2;
 107
 108         /* (CS0, CS1, DIR, OE) <= (CFCE1, CFCE2, CFRNW, NCSX) timings */
 109         ncs_read_setup = 1;
 110         ncs_read_pulse = read_cycle - 2;
 111
 112         /* Write timings same as read timings */
 113         write_cycle = read_cycle;
 114         nwe_setup = nrd_setup;
 115         nwe_pulse = nrd_pulse;
 116         ncs_write_setup = ncs_read_setup;
 117         ncs_write_pulse = ncs_read_pulse;
 118
 119         dev_dbg(dev, "ATA timings: nrd_setup = %lu nrd_pulse = %lu nrd_cycle = %lu\n",
 120                         nrd_setup, nrd_pulse, read_cycle);
 121         dev_dbg(dev, "ATA timings: nwe_setup = %lu nwe_pulse = %lu nwe_cycle = %lu\n",
 122                         nwe_setup, nwe_pulse, write_cycle);
 123         dev_dbg(dev, "ATA timings: ncs_read_setup = %lu ncs_read_pulse = %lu\n",
 124                         ncs_read_setup, ncs_read_pulse);
 125         dev_dbg(dev, "ATA timings: ncs_write_setup = %lu ncs_write_pulse = %lu\n",
 126                         ncs_write_setup, ncs_write_pulse);
 127
 128         at91_sys_write(AT91_SMC_SETUP(info->cs),
 129                         AT91_SMC_NWESETUP_(nwe_setup) |
 130                         AT91_SMC_NRDSETUP_(nrd_setup) |
 131                         AT91_SMC_NCS_WRSETUP_(ncs_write_setup) |
 132                         AT91_SMC_NCS_RDSETUP_(ncs_read_setup));
 133
 134         at91_sys_write(AT91_SMC_PULSE(info->cs),
 135                         AT91_SMC_NWEPULSE_(nwe_pulse) |
 136                         AT91_SMC_NRDPULSE_(nrd_pulse) |
 137                         AT91_SMC_NCS_WRPULSE_(ncs_write_pulse) |
 138                         AT91_SMC_NCS_RDPULSE_(ncs_read_pulse));
 139
 140         at91_sys_write(AT91_SMC_CYCLE(info->cs),
 141                         AT91_SMC_NWECYCLE_(write_cycle) |
 142                         AT91_SMC_NRDCYCLE_(read_cycle));
 143
 144         return;
 145 }
 146
 147 static void pata_at91_set_piomode(struct ata_port *ap, struct ata_device *adev)
 148 {
 149         struct at91_ide_info *info = ap->host->private_data;
 150         struct ata_timing timing;
 151         int ret;
 152
 153         /* Compute ATA timing and set it to SMC */
 154         ret = ata_timing_compute(adev, adev->pio_mode, &timing, 1000, 0);
 155         if (ret) {
 156                 dev_warn(ap->dev, "Failed to compute ATA timing %d, \
 157                                 set PIO_0 timing\n", ret);
 158                 set_smc_timing(ap->dev, info, &initial_timing);
 159         } else {
 160                 set_smc_timing(ap->dev, info, &timing);
 161         }
 162
 163         /* Setup SMC mode */
 164         set_smc_mode(info);
 165
 166         return;
 167 }
 168
 169 static unsigned int pata_at91_data_xfer_noirq(struct ata_device *dev,
 170                 unsigned char *buf, unsigned int buflen, int rw)
 171 {
 172         struct at91_ide_info *info = dev->link->ap->host->private_data;
 173         unsigned int consumed;
 174         unsigned long flags;
 175         unsigned int mode;
 176
 177         local_irq_save(flags);
 178         mode = at91_sys_read(AT91_SMC_MODE(info->cs));
 179
 180         /* set 16bit mode before writing data */
 181         at91_sys_write(AT91_SMC_MODE(info->cs),
 182                         (mode & ~AT91_SMC_DBW) | AT91_SMC_DBW_16);
 183
 184         consumed = ata_sff_data_xfer(dev, buf, buflen, rw);
 185
 186         /* restore 8bit mode after data is written */
 187         at91_sys_write(AT91_SMC_MODE(info->cs),
 188                         (mode & ~AT91_SMC_DBW) | AT91_SMC_DBW_8);
 189
 190         local_irq_restore(flags);
 191         return consumed;
 192 }
 193
 194 static struct scsi_host_template pata_at91_sht = {
 195         ATA_PIO_SHT(DRV_NAME),
 196 };
 197
 198 static struct ata_port_operations pata_at91_port_ops = {
 199         .inherits       = &ata_sff_port_ops,
 200
 201         .sff_data_xfer  = pata_at91_data_xfer_noirq,
 202         .set_piomode    = pata_at91_set_piomode,
 203         .cable_detect   = ata_cable_40wire,
 204         .port_start     = ATA_OP_NULL,
 205 };
 206
 207 static int __devinit pata_at91_probe(struct platform_device *pdev)
 208 {
 209         struct at91_cf_data *board = pdev->dev.platform_data;
 210         struct device *dev = &pdev->dev;
 211         struct at91_ide_info *info;
 212         struct resource *mem_res;
 213         struct ata_host *host;
 214         struct ata_port *ap;
 215
 216         int irq_flags = 0;
 217         int irq = 0;
 218         int ret;
 219
 220         /*  get platform resources: IO/CTL memories and irq/rst pins */
 221
 222         if (pdev->num_resources != 1) {
 223                 dev_err(&pdev->dev, "invalid number of resources\n");
 224                 return -EINVAL;
 225         }
 226
 227         mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 228
 229         if (!mem_res) {
 230                 dev_err(dev, "failed to get mem resource\n");
 231                 return -EINVAL;
 232         }
 233
 234         irq = board->irq_pin;
 235
 236         /* init ata host */
 237
 238         host = ata_host_alloc(dev, 1);
 239
 240         if (!host)
 241                 return -ENOMEM;
 242
 243         ap = host->ports[0];
 244         ap->ops = &pata_at91_port_ops;
 245         ap->flags |= ATA_FLAG_SLAVE_POSS;
 246         ap->pio_mask = ATA_PIO4;
 247
 248         if (!irq) {
 249                 ap->flags |= ATA_FLAG_PIO_POLLING;
 250                 ata_port_desc(ap, "no IRQ, using PIO polling");
 251         }
 252
 253         info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
 254
 255         if (!info) {
 256                 dev_err(dev, "failed to allocate memory for private data\n");
 257                 return -ENOMEM;
 258         }
 259
 260         info->mck = clk_get(NULL, "mck");
 261
 262         if (IS_ERR(info->mck)) {
 263                 dev_err(dev, "failed to get access to mck clock\n");
 264                 return -ENODEV;
 265         }
 266
 267         info->cs    = board->chipselect;
 268         info->mode  = AT91_SMC_READMODE | AT91_SMC_WRITEMODE |
 269                 AT91_SMC_EXNWMODE_READY | AT91_SMC_BAT_SELECT |
 270                 AT91_SMC_DBW_8 | AT91_SMC_TDF_(0);
 271
 272         info->ide_addr = devm_ioremap(dev,
 273                         mem_res->start + CF_IDE_OFFSET, CF_IDE_RES_SIZE);
 274
 275         if (!info->ide_addr) {
 276                 dev_err(dev, "failed to map IO base\n");
 277                 ret = -ENOMEM;
 278                 goto err_put;
 279         }
 280
 281         info->alt_addr = devm_ioremap(dev,
 282                         mem_res->start + CF_ALT_IDE_OFFSET, CF_IDE_RES_SIZE);
 283
 284         if (!info->alt_addr) {
 285                 dev_err(dev, "failed to map CTL base\n");
 286                 ret = -ENOMEM;
 287                 goto err_put;
 288         }
 289
 290         ap->ioaddr.cmd_addr = info->ide_addr;
 291         ap->ioaddr.ctl_addr = info->alt_addr + 0x06;
 292         ap->ioaddr.altstatus_addr = ap->ioaddr.ctl_addr;
 293
 294         ata_sff_std_ports(&ap->ioaddr);
 295
 296         ata_port_desc(ap, "mmio cmd 0x%llx ctl 0x%llx",
 297                         (unsigned long long)mem_res->start + CF_IDE_OFFSET,
 298                         (unsigned long long)mem_res->start + CF_ALT_IDE_OFFSET);
 299
 300         host->private_data = info;
 301
 302         return ata_host_activate(host, irq ? gpio_to_irq(irq) : 0,
 303                         irq ? ata_sff_interrupt : NULL,
 304                         irq_flags, &pata_at91_sht);
 305
 306 err_put:
 307         clk_put(info->mck);
 308         return ret;
 309 }
 310
 311 static int __devexit pata_at91_remove(struct platform_device *pdev)
 312 {
 313         struct ata_host *host = dev_get_drvdata(&pdev->dev);
 314         struct at91_ide_info *info;
 315
 316         if (!host)
 317                 return 0;
 318         info = host->private_data;
 319
 320         ata_host_detach(host);
 321
 322         if (!info)
 323                 return 0;
 324
 325         clk_put(info->mck);
 326
 327         return 0;
 328 }
 329
 330 static struct platform_driver pata_at91_driver = {
 331         .probe          = pata_at91_probe,
 332         .remove         = __devexit_p(pata_at91_remove),
 333         .driver         = {
 334                 .name           = DRV_NAME,
 335                 .owner          = THIS_MODULE,
 336         },
 337 };
 338
 339 static int __init pata_at91_init(void)
 340 {
 341         return platform_driver_register(&pata_at91_driver);
 342 }
 343
 344 static void __exit pata_at91_exit(void)
 345 {
 346         platform_driver_unregister(&pata_at91_driver);
 347 }
 348
 349
 350 module_init(pata_at91_init);
 351 module_exit(pata_at91_exit);
 352
 353
 354 MODULE_LICENSE("GPL");
 355 MODULE_DESCRIPTION("Driver for CF in True IDE mode on AT91SAM9260 SoC");
 356 MODULE_AUTHOR("Matyukevich Sergey");
 357 MODULE_VERSION(DRV_VERSION);
 358