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         set_irq_type(info->irq, IRQ_TYPE_LEVEL_HIGH);
  68 }
  69
  70 static void rb532_pata_exec_command(struct ata_port *ap,
  71                                 const struct ata_taskfile *tf)
  72 {
  73         writeb(tf->command, ap->ioaddr.command_addr);
  74         rb532_pata_finish_io(ap);
  75 }
  76
  77 static unsigned int rb532_pata_data_xfer(struct ata_device *adev, unsigned char *buf,
  78                                 unsigned int buflen, int write_data)
  79 {
  80         struct ata_port *ap = adev->link->ap;
  81         void __iomem *ioaddr = ap->ioaddr.data_addr;
  82         int retlen = buflen;
  83
  84         if (write_data) {
  85                 for (; buflen > 0; buflen--, buf++)
  86                         writeb(*buf, ioaddr);
  87         } else {
  88                 for (; buflen > 0; buflen--, buf++)
  89                         *buf = readb(ioaddr);
  90         }
  91
  92         rb532_pata_finish_io(adev->link->ap);
  93         return retlen;
  94 }
  95
  96 static void rb532_pata_freeze(struct ata_port *ap)
  97 {
  98         struct rb532_cf_info *info = ap->host->private_data;
  99
 100         info->frozen = 1;
 101 }
 102
 103 static void rb532_pata_thaw(struct ata_port *ap)
 104 {
 105         struct rb532_cf_info *info = ap->host->private_data;
 106
 107         info->frozen = 0;
 108 }
 109
 110 static irqreturn_t rb532_pata_irq_handler(int irq, void *dev_instance)
 111 {
 112         struct ata_host *ah = dev_instance;
 113         struct rb532_cf_info *info = ah->private_data;
 114
 115         if (gpio_get_value(info->gpio_line)) {
 116                 set_irq_type(info->irq, IRQ_TYPE_LEVEL_LOW);
 117                 if (!info->frozen)
 118                         ata_sff_interrupt(info->irq, dev_instance);
 119         } else {
 120                 set_irq_type(info->irq, IRQ_TYPE_LEVEL_HIGH);
 121         }
 122
 123         return IRQ_HANDLED;
 124 }
 125
 126 static struct ata_port_operations rb532_pata_port_ops = {
 127         .inherits               = &ata_sff_port_ops,
 128         .sff_exec_command       = rb532_pata_exec_command,
 129         .sff_data_xfer          = rb532_pata_data_xfer,
 130         .freeze                 = rb532_pata_freeze,
 131         .thaw                   = rb532_pata_thaw,
 132 };
 133
 134 /* ------------------------------------------------------------------------ */
 135
 136 static struct scsi_host_template rb532_pata_sht = {
 137         ATA_PIO_SHT(DRV_NAME),
 138 };
 139
 140 /* ------------------------------------------------------------------------ */
 141
 142 static void rb532_pata_setup_ports(struct ata_host *ah)
 143 {
 144         struct rb532_cf_info *info = ah->private_data;
 145         struct ata_port *ap;
 146
 147         ap = ah->ports[0];
 148
 149         ap->ops         = &rb532_pata_port_ops;
 150         ap->pio_mask    = 0x1f; /* PIO4 */
 151         ap->flags       = ATA_FLAG_NO_LEGACY | ATA_FLAG_MMIO;
 152
 153         ap->ioaddr.cmd_addr     = info->iobase + RB500_CF_REG_BASE;
 154         ap->ioaddr.ctl_addr     = info->iobase + RB500_CF_REG_CTRL;
 155         ap->ioaddr.altstatus_addr = info->iobase + RB500_CF_REG_CTRL;
 156
 157         ata_sff_std_ports(&ap->ioaddr);
 158
 159         ap->ioaddr.data_addr    = info->iobase + RB500_CF_REG_DBUF32;
 160         ap->ioaddr.error_addr   = info->iobase + RB500_CF_REG_ERR;
 161 }
 162
 163 static __devinit int rb532_pata_driver_probe(struct platform_device *pdev)
 164 {
 165         unsigned int irq;
 166         int gpio;
 167         struct resource *res;
 168         struct ata_host *ah;
 169         struct rb532_cf_info *info;
 170         int ret;
 171
 172         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 173         if (!res) {
 174                 dev_err(&pdev->dev, "no IOMEM resource found\n");
 175                 return -EINVAL;
 176         }
 177
 178         irq = platform_get_irq(pdev, 0);
 179         if (irq <= 0) {
 180                 dev_err(&pdev->dev, "no IRQ resource found\n");
 181                 return -ENOENT;
 182         }
 183
 184         gpio = irq_to_gpio(irq);
 185         if (gpio < 0) {
 186                 dev_err(&pdev->dev, "no GPIO found for irq%d\n", irq);
 187                 return -ENOENT;
 188         }
 189
 190         ret = gpio_request(gpio, DRV_NAME);
 191         if (ret) {
 192                 dev_err(&pdev->dev, "GPIO request failed\n");
 193                 return ret;
 194         }
 195
 196         /* allocate host */
 197         ah = ata_host_alloc(&pdev->dev, RB500_CF_MAXPORTS);
 198         if (!ah)
 199                 return -ENOMEM;
 200
 201         platform_set_drvdata(pdev, ah);
 202
 203         info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
 204         if (!info)
 205                 return -ENOMEM;
 206
 207         ah->private_data = info;
 208         info->gpio_line = gpio;
 209         info->irq = irq;
 210
 211         info->iobase = devm_ioremap_nocache(&pdev->dev, res->start,
 212                                 res->end - res->start + 1);
 213         if (!info->iobase)
 214                 return -ENOMEM;
 215
 216         ret = gpio_direction_input(gpio);
 217         if (ret) {
 218                 dev_err(&pdev->dev, "unable to set GPIO direction, err=%d\n",
 219                                 ret);
 220                 goto err_free_gpio;
 221         }
 222
 223         rb532_pata_setup_ports(ah);
 224
 225         ret = ata_host_activate(ah, irq, rb532_pata_irq_handler,
 226                                 IRQF_TRIGGER_LOW, &rb532_pata_sht);
 227         if (ret)
 228                 goto err_free_gpio;
 229
 230         return 0;
 231
 232 err_free_gpio:
 233         gpio_free(gpio);
 234
 235         return ret;
 236 }
 237
 238 static __devexit int rb532_pata_driver_remove(struct platform_device *pdev)
 239 {
 240         struct ata_host *ah = platform_get_drvdata(pdev);
 241         struct rb532_cf_info *info = ah->private_data;
 242
 243         ata_host_detach(ah);
 244         gpio_free(info->gpio_line);
 245
 246         return 0;
 247 }
 248
 249 /* work with hotplug and coldplug */
 250 MODULE_ALIAS("platform:" DRV_NAME);
 251
 252 static struct platform_driver rb532_pata_platform_driver = {
 253         .probe          = rb532_pata_driver_probe,
 254         .remove         = __devexit_p(rb532_pata_driver_remove),
 255         .driver  = {
 256                 .name   = DRV_NAME,
 257                 .owner  = THIS_MODULE,
 258         },
 259 };
 260
 261 /* ------------------------------------------------------------------------ */
 262
 263 #define DRV_INFO DRV_DESC " version " DRV_VERSION
 264
 265 static int __init rb532_pata_module_init(void)
 266 {
 267         printk(KERN_INFO DRV_INFO "\n");
 268
 269         return platform_driver_register(&rb532_pata_platform_driver);
 270 }
 271
 272 static void __exit rb532_pata_module_exit(void)
 273 {
 274         platform_driver_unregister(&rb532_pata_platform_driver);
 275 }
 276
 277 MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>");
 278 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
 279 MODULE_DESCRIPTION(DRV_DESC);
 280 MODULE_VERSION(DRV_VERSION);
 281 MODULE_LICENSE("GPL");
 282
 283 module_init(rb532_pata_module_init);
 284 module_exit(rb532_pata_module_exit);