drivers/ata/pata_rb532_cf.c

   1 /*
   2  *  A low-level PATA driver to handle a Compact Flash connected on the
   3  *  Mikrotik's RouterBoard 532 board.
   4  *
   5  *  Copyright (C) 2007 Gabor Juhos <juhosg at openwrt.org>
   6  *  Copyright (C) 2008 Florian Fainelli <florian@openwrt.org>
   7  *
   8  *  This file was based on: drivers/ata/pata_ixp4xx_cf.c
   9  *      Copyright (C) 2006-07 Tower Technologies
  10  *      Author: Alessandro Zummo <a.zummo@towertech.it>
  11  *
  12  *  Also was based on the driver for Linux 2.4.xx published by Mikrotik for
  13  *  their RouterBoard 1xx and 5xx series devices. The original Mikrotik code
  14  *  seems not to have a license.
  15  *
  16  *  This program is free software; you can redistribute it and/or modify
  17  *  it under the terms of the GNU General Public License version 2 as
  18  *  published by the Free Software Foundation.
  19  *
  20  */
  21
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/platform_device.h>
  25
  26 #include <linux/io.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/irq.h>
  29
  30 #include <linux/libata.h>
  31 #include <scsi/scsi_host.h>
  32
  33 #include <asm/gpio.h>
  34
  35 #define DRV_NAME        "pata-rb532-cf"
  36 #define DRV_VERSION     "0.1.0"
  37 #define DRV_DESC        "PATA driver for RouterBOARD 532 Compact Flash"
  38
  39 #define RB500_CF_MAXPORTS       1
  40 #define RB500_CF_IO_DELAY       400
  41
  42 #define RB500_CF_REG_BASE       0x0800
  43 #define RB500_CF_REG_ERR        0x080D
  44 #define RB500_CF_REG_CTRL       0x080E
  45 /* 32bit buffered data register offset */
  46 #define RB500_CF_REG_DBUF32     0x0C00
  47
  48 struct rb532_cf_info {
  49         void __iomem    *iobase;
  50         unsigned int    gpio_line;
  51         int             frozen;
  52         unsigned int    irq;
  53 };
  54
  55 /* ------------------------------------------------------------------------ */
  56
  57 static inline void rb532_pata_finish_io(struct ata_port *ap)
  58 {
  59         struct ata_host *ah = ap->host;
  60         struct rb532_cf_info *info = ah->private_data;
  61
  62         /* FIXME: Keep previous delay. If this is merely a fence then
  63            ata_sff_sync might be sufficient. */
  64         ata_sff_dma_pause(ap);
  65         ndelay(RB500_CF_IO_DELAY);
  66 }
  67
  68 static void rb532_pata_exec_command(struct ata_port *ap,
  69                                 const struct ata_taskfile *tf)
  70 {
  71         writeb(tf->command, ap->ioaddr.command_addr);
  72         rb532_pata_finish_io(ap);
  73 }
  74
  75 static unsigned int rb532_pata_data_xfer(struct ata_device *adev, unsigned char *buf,
  76                                 unsigned int buflen, int write_data)
  77 {
  78         struct ata_port *ap = adev->link->ap;
  79         void __iomem *ioaddr = ap->ioaddr.data_addr;
  80         int retlen = buflen;
  81
  82         if (write_data) {
  83                 for (; buflen > 0; buflen--, buf++)
  84                         writeb(*buf, ioaddr);
  85         } else {
  86                 for (; buflen > 0; buflen--, buf++)
  87                         *buf = readb(ioaddr);
  88         }
  89
  90         rb532_pata_finish_io(adev->link->ap);
  91         return retlen;
  92 }
  93
  94 static void rb532_pata_freeze(struct ata_port *ap)
  95 {
  96         struct rb532_cf_info *info = ap->host->private_data;
  97
  98         info->frozen = 1;
  99 }
 100
 101 static void rb532_pata_thaw(struct ata_port *ap)
 102 {
 103         struct rb532_cf_info *info = ap->host->private_data;
 104
 105         info->frozen = 0;
 106 }
 107
 108 static irqreturn_t rb532_pata_irq_handler(int irq, void *dev_instance)
 109 {
 110         struct ata_host *ah = dev_instance;
 111         struct rb532_cf_info *info = ah->private_data;
 112
 113         if (gpio_get_value(info->gpio_line)) {
 114                 set_irq_type(info->irq, IRQ_TYPE_LEVEL_LOW);
 115                 if (!info->frozen)
 116                         ata_sff_interrupt(info->irq, dev_instance);
 117         } else {
 118                 set_irq_type(info->irq, IRQ_TYPE_LEVEL_HIGH);
 119         }
 120
 121         return IRQ_HANDLED;
 122 }
 123
 124 static struct ata_port_operations rb532_pata_port_ops = {
 125         .inherits               = &ata_sff_port_ops,
 126         .sff_exec_command       = rb532_pata_exec_command,
 127         .sff_data_xfer          = rb532_pata_data_xfer,
 128         .freeze                 = rb532_pata_freeze,
 129         .thaw                   = rb532_pata_thaw,
 130 };
 131
 132 /* ------------------------------------------------------------------------ */
 133
 134 static struct scsi_host_template rb532_pata_sht = {
 135         ATA_PIO_SHT(DRV_NAME),
 136 };
 137
 138 /* ------------------------------------------------------------------------ */
 139
 140 static void rb532_pata_setup_ports(struct ata_host *ah)
 141 {
 142         struct rb532_cf_info *info = ah->private_data;
 143         struct ata_port *ap;
 144
 145         ap = ah->ports[0];
 146
 147         ap->ops         = &rb532_pata_port_ops;
 148         ap->pio_mask    = 0x1f; /* PIO4 */
 149         ap->flags       = ATA_FLAG_NO_LEGACY | ATA_FLAG_MMIO;
 150
 151         ap->ioaddr.cmd_addr     = info->iobase + RB500_CF_REG_BASE;
 152         ap->ioaddr.ctl_addr     = info->iobase + RB500_CF_REG_CTRL;
 153         ap->ioaddr.altstatus_addr = info->iobase + RB500_CF_REG_CTRL;
 154
 155         ata_sff_std_ports(&ap->ioaddr);
 156
 157         ap->ioaddr.data_addr    = info->iobase + RB500_CF_REG_DBUF32;
 158         ap->ioaddr.error_addr   = info->iobase + RB500_CF_REG_ERR;
 159 }
 160
 161 static __devinit int rb532_pata_driver_probe(struct platform_device *pdev)
 162 {
 163         unsigned int irq;
 164         int gpio;
 165         struct resource *res;
 166         struct ata_host *ah;
 167         struct rb532_cf_info *info;
 168         int ret;
 169
 170         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 171         if (!res) {
 172                 dev_err(&pdev->dev, "no IOMEM resource found\n");
 173                 return -EINVAL;
 174         }
 175
 176         irq = platform_get_irq(pdev, 0);
 177         if (irq <= 0) {
 178                 dev_err(&pdev->dev, "no IRQ resource found\n");
 179                 return -ENOENT;
 180         }
 181
 182         gpio = irq_to_gpio(irq);
 183         if (gpio < 0) {
 184                 dev_err(&pdev->dev, "no GPIO found for irq%d\n", irq);
 185                 return -ENOENT;
 186         }
 187
 188         ret = gpio_request(gpio, DRV_NAME);
 189         if (ret) {
 190                 dev_err(&pdev->dev, "GPIO request failed\n");
 191                 return ret;
 192         }
 193
 194         /* allocate host */
 195         ah = ata_host_alloc(&pdev->dev, RB500_CF_MAXPORTS);
 196         if (!ah)
 197                 return -ENOMEM;
 198
 199         platform_set_drvdata(pdev, ah);
 200
 201         info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
 202         if (!info)
 203                 return -ENOMEM;
 204
 205         ah->private_data = info;
 206         info->gpio_line = gpio;
 207         info->irq = irq;
 208
 209         info->iobase = devm_ioremap_nocache(&pdev->dev, res->start,
 210                                 res->end - res->start + 1);
 211         if (!info->iobase)
 212                 return -ENOMEM;
 213
 214         ret = gpio_direction_input(gpio);
 215         if (ret) {
 216                 dev_err(&pdev->dev, "unable to set GPIO direction, err=%d\n",
 217                                 ret);
 218                 goto err_free_gpio;
 219         }
 220
 221         rb532_pata_setup_ports(ah);
 222
 223         ret = ata_host_activate(ah, irq, rb532_pata_irq_handler,
 224                                 IRQF_TRIGGER_LOW, &rb532_pata_sht);
 225         if (ret)
 226                 goto err_free_gpio;
 227
 228         return 0;
 229
 230 err_free_gpio:
 231         gpio_free(gpio);
 232
 233         return ret;
 234 }
 235
 236 static __devexit int rb532_pata_driver_remove(struct platform_device *pdev)
 237 {
 238         struct ata_host *ah = platform_get_drvdata(pdev);
 239         struct rb532_cf_info *info = ah->private_data;
 240
 241         ata_host_detach(ah);
 242         gpio_free(info->gpio_line);
 243
 244         return 0;
 245 }
 246
 247 /* work with hotplug and coldplug */
 248 MODULE_ALIAS("platform:" DRV_NAME);
 249
 250 static struct platform_driver rb532_pata_platform_driver = {
 251         .probe          = rb532_pata_driver_probe,
 252         .remove         = __devexit_p(rb532_pata_driver_remove),
 253         .driver  = {
 254                 .name   = DRV_NAME,
 255                 .owner  = THIS_MODULE,
 256         },
 257 };
 258
 259 /* ------------------------------------------------------------------------ */
 260
 261 #define DRV_INFO DRV_DESC " version " DRV_VERSION
 262
 263 static int __init rb532_pata_module_init(void)
 264 {
 265         printk(KERN_INFO DRV_INFO "\n");
 266
 267         return platform_driver_register(&rb532_pata_platform_driver);
 268 }
 269
 270 static void __exit rb532_pata_module_exit(void)
 271 {
 272         platform_driver_unregister(&rb532_pata_platform_driver);
 273 }
 274
 275 MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>");
 276 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
 277 MODULE_DESCRIPTION(DRV_DESC);
 278 MODULE_VERSION(DRV_VERSION);
 279 MODULE_LICENSE("GPL");
 280
 281 module_init(rb532_pata_module_init);
 282 module_exit(rb532_pata_module_exit);