linux/drivers/ata/pata_at91.c
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   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
  41struct 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
  51static const struct ata_timing initial_timing =
  52        {XFER_PIO_0, 70, 290, 240, 600, 165, 150, 600, 0};
  53
  54static 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
  71static 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
  77static 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
 147static 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
 169static 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
 194static struct scsi_host_template pata_at91_sht = {
 195        ATA_PIO_SHT(DRV_NAME),
 196};
 197
 198static 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
 207static 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
 306err_put:
 307        clk_put(info->mck);
 308        return ret;
 309}
 310
 311static 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
 330static 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
 339static int __init pata_at91_init(void)
 340{
 341        return platform_driver_register(&pata_at91_driver);
 342}
 343
 344static void __exit pata_at91_exit(void)
 345{
 346        platform_driver_unregister(&pata_at91_driver);
 347}
 348
 349
 350module_init(pata_at91_init);
 351module_exit(pata_at91_exit);
 352
 353
 354MODULE_LICENSE("GPL");
 355MODULE_DESCRIPTION("Driver for CF in True IDE mode on AT91SAM9260 SoC");
 356MODULE_AUTHOR("Matyukevich Sergey");
 357MODULE_VERSION(DRV_VERSION);
 358
 359