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 <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/platform_device.h>
  28 #include <linux/ata_platform.h>
  29
  30 #include <mach/at91sam9_smc.h>
  31 #include <mach/board.h>
  32 #include <mach/gpio.h>
  33
  34
  35 #define DRV_NAME "pata_at91"
  36 #define DRV_VERSION "0.1"
  37
  38 #define CF_IDE_OFFSET       0x00c00000
  39 #define CF_ALT_IDE_OFFSET   0x00e00000
  40 #define CF_IDE_RES_SIZE     0x08
  41
  42 struct at91_ide_info {
  43         unsigned long mode;
  44         unsigned int cs;
  45
  46         struct clk *mck;
  47
  48         void __iomem *ide_addr;
  49         void __iomem *alt_addr;
  50 };
  51
  52 static const struct ata_timing initial_timing =
  53         {XFER_PIO_0, 70, 290, 240, 600, 165, 150, 600, 0};
  54
  55 static unsigned long calc_mck_cycles(unsigned long ns, unsigned long mck_hz)
  56 {
  57         unsigned long mul;
  58
  59         /*
  60         * cycles = x [nsec] * f [Hz] / 10^9 [ns in sec] =
  61         *     x * (f / 1_000_000_000) =
  62         *     x * ((f * 65536) / 1_000_000_000) / 65536 =
  63         *     x * (((f / 10_000) * 65536) / 100_000) / 65536 =
  64         */
  65
  66         mul = (mck_hz / 10000) << 16;
  67         mul /= 100000;
  68
  69         return (ns * mul + 65536) >> 16;    /* rounding */
  70 }
  71
  72 static void set_smc_mode(struct at91_ide_info *info)
  73 {
  74         at91_sys_write(AT91_SMC_MODE(info->cs), info->mode);
  75         return;
  76 }
  77
  78 static void set_smc_timing(struct device *dev,
  79                 struct at91_ide_info *info, const struct ata_timing *ata)
  80 {
  81         unsigned long read_cycle, write_cycle, active, recover;
  82         unsigned long nrd_setup, nrd_pulse, nrd_recover;
  83         unsigned long nwe_setup, nwe_pulse;
  84
  85         unsigned long ncs_write_setup, ncs_write_pulse;
  86         unsigned long ncs_read_setup, ncs_read_pulse;
  87
  88         unsigned long mck_hz;
  89
  90         read_cycle  = ata->cyc8b;
  91         nrd_setup   = ata->setup;
  92         nrd_pulse   = ata->act8b;
  93         nrd_recover = ata->rec8b;
  94
  95         mck_hz = clk_get_rate(info->mck);
  96
  97         read_cycle  = calc_mck_cycles(read_cycle, mck_hz);
  98         nrd_setup   = calc_mck_cycles(nrd_setup, mck_hz);
  99         nrd_pulse   = calc_mck_cycles(nrd_pulse, mck_hz);
 100         nrd_recover = calc_mck_cycles(nrd_recover, mck_hz);
 101
 102         active  = nrd_setup + nrd_pulse;
 103         recover = read_cycle - active;
 104
 105         /* Need at least two cycles recovery */
 106         if (recover < 2)
 107                 read_cycle = active + 2;
 108
 109         /* (CS0, CS1, DIR, OE) <= (CFCE1, CFCE2, CFRNW, NCSX) timings */
 110         ncs_read_setup = 1;
 111         ncs_read_pulse = read_cycle - 2;
 112
 113         /* Write timings same as read timings */
 114         write_cycle = read_cycle;
 115         nwe_setup = nrd_setup;
 116         nwe_pulse = nrd_pulse;
 117         ncs_write_setup = ncs_read_setup;
 118         ncs_write_pulse = ncs_read_pulse;
 119
 120         dev_dbg(dev, "ATA timings: nrd_setup = %lu nrd_pulse = %lu nrd_cycle = %lu\n",
 121                         nrd_setup, nrd_pulse, read_cycle);
 122         dev_dbg(dev, "ATA timings: nwe_setup = %lu nwe_pulse = %lu nwe_cycle = %lu\n",
 123                         nwe_setup, nwe_pulse, write_cycle);
 124         dev_dbg(dev, "ATA timings: ncs_read_setup = %lu ncs_read_pulse = %lu\n",
 125                         ncs_read_setup, ncs_read_pulse);
 126         dev_dbg(dev, "ATA timings: ncs_write_setup = %lu ncs_write_pulse = %lu\n",
 127                         ncs_write_setup, ncs_write_pulse);
 128
 129         at91_sys_write(AT91_SMC_SETUP(info->cs),
 130                         AT91_SMC_NWESETUP_(nwe_setup) |
 131                         AT91_SMC_NRDSETUP_(nrd_setup) |
 132                         AT91_SMC_NCS_WRSETUP_(ncs_write_setup) |
 133                         AT91_SMC_NCS_RDSETUP_(ncs_read_setup));
 134
 135         at91_sys_write(AT91_SMC_PULSE(info->cs),
 136                         AT91_SMC_NWEPULSE_(nwe_pulse) |
 137                         AT91_SMC_NRDPULSE_(nrd_pulse) |
 138                         AT91_SMC_NCS_WRPULSE_(ncs_write_pulse) |
 139                         AT91_SMC_NCS_RDPULSE_(ncs_read_pulse));
 140
 141         at91_sys_write(AT91_SMC_CYCLE(info->cs),
 142                         AT91_SMC_NWECYCLE_(write_cycle) |
 143                         AT91_SMC_NRDCYCLE_(read_cycle));
 144
 145         return;
 146 }
 147
 148 static void pata_at91_set_piomode(struct ata_port *ap, struct ata_device *adev)
 149 {
 150         struct at91_ide_info *info = ap->host->private_data;
 151         struct ata_timing timing;
 152         int ret;
 153
 154         /* Compute ATA timing and set it to SMC */
 155         ret = ata_timing_compute(adev, adev->pio_mode, &timing, 1000, 0);
 156         if (ret) {
 157                 dev_warn(ap->dev, "Failed to compute ATA timing %d, "
 158                          "set PIO_0 timing\n", ret);
 159                 set_smc_timing(ap->dev, info, &initial_timing);
 160         } else {
 161                 set_smc_timing(ap->dev, info, &timing);
 162         }
 163
 164         /* Setup SMC mode */
 165         set_smc_mode(info);
 166
 167         return;
 168 }
 169
 170 static unsigned int pata_at91_data_xfer_noirq(struct ata_device *dev,
 171                 unsigned char *buf, unsigned int buflen, int rw)
 172 {
 173         struct at91_ide_info *info = dev->link->ap->host->private_data;
 174         unsigned int consumed;
 175         unsigned long flags;
 176         unsigned int mode;
 177
 178         local_irq_save(flags);
 179         mode = at91_sys_read(AT91_SMC_MODE(info->cs));
 180
 181         /* set 16bit mode before writing data */
 182         at91_sys_write(AT91_SMC_MODE(info->cs),
 183                         (mode & ~AT91_SMC_DBW) | AT91_SMC_DBW_16);
 184
 185         consumed = ata_sff_data_xfer(dev, buf, buflen, rw);
 186
 187         /* restore 8bit mode after data is written */
 188         at91_sys_write(AT91_SMC_MODE(info->cs),
 189                         (mode & ~AT91_SMC_DBW) | AT91_SMC_DBW_8);
 190
 191         local_irq_restore(flags);
 192         return consumed;
 193 }
 194
 195 static struct scsi_host_template pata_at91_sht = {
 196         ATA_PIO_SHT(DRV_NAME),
 197 };
 198
 199 static struct ata_port_operations pata_at91_port_ops = {
 200         .inherits       = &ata_sff_port_ops,
 201
 202         .sff_data_xfer  = pata_at91_data_xfer_noirq,
 203         .set_piomode    = pata_at91_set_piomode,
 204         .cable_detect   = ata_cable_40wire,
 205         .port_start     = ATA_OP_NULL,
 206 };
 207
 208 static int __devinit pata_at91_probe(struct platform_device *pdev)
 209 {
 210         struct at91_cf_data *board = pdev->dev.platform_data;
 211         struct device *dev = &pdev->dev;
 212         struct at91_ide_info *info;
 213         struct resource *mem_res;
 214         struct ata_host *host;
 215         struct ata_port *ap;
 216
 217         int irq_flags = 0;
 218         int irq = 0;
 219         int ret;
 220
 221         /*  get platform resources: IO/CTL memories and irq/rst pins */
 222
 223         if (pdev->num_resources != 1) {
 224                 dev_err(&pdev->dev, "invalid number of resources\n");
 225                 return -EINVAL;
 226         }
 227
 228         mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 229
 230         if (!mem_res) {
 231                 dev_err(dev, "failed to get mem resource\n");
 232                 return -EINVAL;
 233         }
 234
 235         irq = board->irq_pin;
 236
 237         /* init ata host */
 238
 239         host = ata_host_alloc(dev, 1);
 240
 241         if (!host)
 242                 return -ENOMEM;
 243
 244         ap = host->ports[0];
 245         ap->ops = &pata_at91_port_ops;
 246         ap->flags |= ATA_FLAG_SLAVE_POSS;
 247         ap->pio_mask = ATA_PIO4;
 248
 249         if (!irq) {
 250                 ap->flags |= ATA_FLAG_PIO_POLLING;
 251                 ata_port_desc(ap, "no IRQ, using PIO polling");
 252         }
 253
 254         info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
 255
 256         if (!info) {
 257                 dev_err(dev, "failed to allocate memory for private data\n");
 258                 return -ENOMEM;
 259         }
 260
 261         info->mck = clk_get(NULL, "mck");
 262
 263         if (IS_ERR(info->mck)) {
 264                 dev_err(dev, "failed to get access to mck clock\n");
 265                 return -ENODEV;
 266         }
 267
 268         info->cs    = board->chipselect;
 269         info->mode  = AT91_SMC_READMODE | AT91_SMC_WRITEMODE |
 270                 AT91_SMC_EXNWMODE_READY | AT91_SMC_BAT_SELECT |
 271                 AT91_SMC_DBW_8 | AT91_SMC_TDF_(0);
 272
 273         info->ide_addr = devm_ioremap(dev,
 274                         mem_res->start + CF_IDE_OFFSET, CF_IDE_RES_SIZE);
 275
 276         if (!info->ide_addr) {
 277                 dev_err(dev, "failed to map IO base\n");
 278                 ret = -ENOMEM;
 279                 goto err_put;
 280         }
 281
 282         info->alt_addr = devm_ioremap(dev,
 283                         mem_res->start + CF_ALT_IDE_OFFSET, CF_IDE_RES_SIZE);
 284
 285         if (!info->alt_addr) {
 286                 dev_err(dev, "failed to map CTL base\n");
 287                 ret = -ENOMEM;
 288                 goto err_put;
 289         }
 290
 291         ap->ioaddr.cmd_addr = info->ide_addr;
 292         ap->ioaddr.ctl_addr = info->alt_addr + 0x06;
 293         ap->ioaddr.altstatus_addr = ap->ioaddr.ctl_addr;
 294
 295         ata_sff_std_ports(&ap->ioaddr);
 296
 297         ata_port_desc(ap, "mmio cmd 0x%llx ctl 0x%llx",
 298                         (unsigned long long)mem_res->start + CF_IDE_OFFSET,
 299                         (unsigned long long)mem_res->start + CF_ALT_IDE_OFFSET);
 300
 301         host->private_data = info;
 302
 303         return ata_host_activate(host, irq ? gpio_to_irq(irq) : 0,
 304                         irq ? ata_sff_interrupt : NULL,
 305                         irq_flags, &pata_at91_sht);
 306
 307 err_put:
 308         clk_put(info->mck);
 309         return ret;
 310 }
 311
 312 static int __devexit pata_at91_remove(struct platform_device *pdev)
 313 {
 314         struct ata_host *host = dev_get_drvdata(&pdev->dev);
 315         struct at91_ide_info *info;
 316
 317         if (!host)
 318                 return 0;
 319         info = host->private_data;
 320
 321         ata_host_detach(host);
 322
 323         if (!info)
 324                 return 0;
 325
 326         clk_put(info->mck);
 327
 328         return 0;
 329 }
 330
 331 static struct platform_driver pata_at91_driver = {
 332         .probe          = pata_at91_probe,
 333         .remove         = __devexit_p(pata_at91_remove),
 334         .driver         = {
 335                 .name           = DRV_NAME,
 336                 .owner          = THIS_MODULE,
 337         },
 338 };
 339
 340 static int __init pata_at91_init(void)
 341 {
 342         return platform_driver_register(&pata_at91_driver);
 343 }
 344
 345 static void __exit pata_at91_exit(void)
 346 {
 347         platform_driver_unregister(&pata_at91_driver);
 348 }
 349
 350
 351 module_init(pata_at91_init);
 352 module_exit(pata_at91_exit);
 353
 354
 355 MODULE_LICENSE("GPL");
 356 MODULE_DESCRIPTION("Driver for CF in True IDE mode on AT91SAM9260 SoC");
 357 MODULE_AUTHOR("Matyukevich Sergey");
 358 MODULE_VERSION(DRV_VERSION);
 359