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_CMD        0x0800
  43 #define RB500_CF_REG_CTRL       0x080E
  44 #define RB500_CF_REG_DATA       0x0C00
  45
  46 struct rb532_cf_info {
  47         void __iomem    *iobase;
  48         unsigned int    gpio_line;
  49         int             frozen;
  50         unsigned int    irq;
  51 };
  52
  53 /* ------------------------------------------------------------------------ */
  54
  55 static inline void rb532_pata_finish_io(struct ata_port *ap)
  56 {
  57         struct ata_host *ah = ap->host;
  58         struct rb532_cf_info *info = ah->private_data;
  59
  60         /* FIXME: Keep previous delay. If this is merely a fence then
  61            ata_sff_sync might be sufficient. */
  62         ata_sff_dma_pause(ap);
  63         ndelay(RB500_CF_IO_DELAY);
  64
  65         set_irq_type(info->irq, IRQ_TYPE_LEVEL_HIGH);
  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 void 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
  81         if (write_data) {
  82                 for (; buflen > 0; buflen--, buf++)
  83                         writeb(*buf, ioaddr);
  84         } else {
  85                 for (; buflen > 0; buflen--, buf++)
  86                         *buf = readb(ioaddr);
  87         }
  88
  89         rb532_pata_finish_io(adev->link->ap);
  90 }
  91
  92 static void rb532_pata_freeze(struct ata_port *ap)
  93 {
  94         struct rb532_cf_info *info = ap->host->private_data;
  95
  96         info->frozen = 1;
  97 }
  98
  99 static void rb532_pata_thaw(struct ata_port *ap)
 100 {
 101         struct rb532_cf_info *info = ap->host->private_data;
 102
 103         info->frozen = 0;
 104 }
 105
 106 static irqreturn_t rb532_pata_irq_handler(int irq, void *dev_instance)
 107 {
 108         struct ata_host *ah = dev_instance;
 109         struct rb532_cf_info *info = ah->private_data;
 110
 111         if (gpio_get_value(info->gpio_line)) {
 112                 set_irq_type(info->irq, IRQ_TYPE_LEVEL_LOW);
 113                 if (!info->frozen)
 114                         ata_sff_interrupt(info->irq, dev_instance);
 115         } else {
 116                 set_irq_type(info->irq, IRQ_TYPE_LEVEL_HIGH);
 117         }
 118
 119         return IRQ_HANDLED;
 120 }
 121
 122 static struct ata_port_operations rb532_pata_port_ops = {
 123         .inherits               = &ata_sff_port_ops,
 124         .sff_exec_command       = rb532_pata_exec_command,
 125         .sff_data_xfer          = rb532_pata_data_xfer,
 126         .freeze                 = rb532_pata_freeze,
 127         .thaw                   = rb532_pata_thaw,
 128 };
 129
 130 /* ------------------------------------------------------------------------ */
 131
 132 static struct scsi_host_template rb532_pata_sht = {
 133         ATA_PIO_SHT(DRV_NAME),
 134 };
 135
 136 /* ------------------------------------------------------------------------ */
 137
 138 static void rb532_pata_setup_ports(struct ata_host *ah)
 139 {
 140         struct rb532_cf_info *info = ah->private_data;
 141         struct ata_port *ap;
 142
 143         ap = ah->ports[0];
 144
 145         ap->ops         = &rb532_pata_port_ops;
 146         ap->pio_mask    = 0x1f; /* PIO4 */
 147         ap->flags       = ATA_FLAG_NO_LEGACY | ATA_FLAG_MMIO;
 148
 149         ap->ioaddr.cmd_addr     = info->iobase + RB500_CF_REG_CMD;
 150         ap->ioaddr.ctl_addr     = info->iobase + RB500_CF_REG_CTRL;
 151         ap->ioaddr.altstatus_addr = info->iobase + RB500_CF_REG_CTRL;
 152
 153         ata_sff_std_ports(&ap->ioaddr);
 154
 155         ap->ioaddr.data_addr    = info->iobase + RB500_CF_REG_DATA;
 156 }
 157
 158 static __devinit int rb532_pata_driver_probe(struct platform_device *pdev)
 159 {
 160         unsigned int irq;
 161         int gpio;
 162         struct resource *res;
 163         struct ata_host *ah;
 164         struct rb532_cf_info *info;
 165         int ret;
 166
 167         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 168         if (!res) {
 169                 dev_err(&pdev->dev, "no IOMEM resource found\n");
 170                 return -EINVAL;
 171         }
 172
 173         irq = platform_get_irq(pdev, 0);
 174         if (irq <= 0) {
 175                 dev_err(&pdev->dev, "no IRQ resource found\n");
 176                 return -ENOENT;
 177         }
 178
 179         gpio = irq_to_gpio(irq);
 180         if (gpio < 0) {
 181                 dev_err(&pdev->dev, "no GPIO found for irq%d\n", irq);
 182                 return -ENOENT;
 183         }
 184
 185         ret = gpio_request(gpio, DRV_NAME);
 186         if (ret) {
 187                 dev_err(&pdev->dev, "GPIO request failed\n");
 188                 return ret;
 189         }
 190
 191         /* allocate host */
 192         ah = ata_host_alloc(&pdev->dev, RB500_CF_MAXPORTS);
 193         if (!ah)
 194                 return -ENOMEM;
 195
 196         platform_set_drvdata(pdev, ah);
 197
 198         info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
 199         if (!info)
 200                 return -ENOMEM;
 201
 202         ah->private_data = info;
 203         info->gpio_line = gpio;
 204         info->irq = irq;
 205
 206         info->iobase = devm_ioremap_nocache(&pdev->dev, res->start,
 207                                 res->end - res->start + 1);
 208         if (!info->iobase)
 209                 return -ENOMEM;
 210
 211         ret = gpio_direction_input(gpio);
 212         if (ret) {
 213                 dev_err(&pdev->dev, "unable to set GPIO direction, err=%d\n",
 214                                 ret);
 215                 goto err_free_gpio;
 216         }
 217
 218         rb532_pata_setup_ports(ah);
 219
 220         ret = ata_host_activate(ah, irq, rb532_pata_irq_handler,
 221                                 IRQF_TRIGGER_LOW, &rb532_pata_sht);
 222         if (ret)
 223                 goto err_free_gpio;
 224
 225         return 0;
 226
 227 err_free_gpio:
 228         gpio_free(gpio);
 229
 230         return ret;
 231 }
 232
 233 static __devexit int rb532_pata_driver_remove(struct platform_device *pdev)
 234 {
 235         struct ata_host *ah = platform_get_drvdata(pdev);
 236         struct rb532_cf_info *info = ah->private_data;
 237
 238         ata_host_detach(ah);
 239         gpio_free(info->gpio_line);
 240
 241         return 0;
 242 }
 243
 244 /* work with hotplug and coldplug */
 245 MODULE_ALIAS("platform:" DRV_NAME);
 246
 247 static struct platform_driver rb532_pata_platform_driver = {
 248         .probe          = rb532_pata_driver_probe,
 249         .remove         = __devexit_p(rb532_pata_driver_remove),
 250         .driver  = {
 251                 .name   = DRV_NAME,
 252                 .owner  = THIS_MODULE,
 253         },
 254 };
 255
 256 /* ------------------------------------------------------------------------ */
 257
 258 #define DRV_INFO DRV_DESC " version " DRV_VERSION
 259
 260 static int __init rb532_pata_module_init(void)
 261 {
 262         printk(KERN_INFO DRV_INFO "\n");
 263
 264         return platform_driver_register(&rb532_pata_platform_driver);
 265 }
 266
 267 static void __exit rb532_pata_module_exit(void)
 268 {
 269         platform_driver_unregister(&rb532_pata_platform_driver);
 270 }
 271
 272 MODULE_AUTHOR("Gabor Juhos <juhosg at openwrt.org>");
 273 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
 274 MODULE_DESCRIPTION(DRV_DESC);
 275 MODULE_VERSION(DRV_VERSION);
 276 MODULE_LICENSE("GPL");
 277
 278 module_init(rb532_pata_module_init);
 279 module_exit(rb532_pata_module_exit);