linux/drivers/mfd/janz-cmodio.c
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   1/*
   2 * Janz CMOD-IO MODULbus Carrier Board PCI Driver
   3 *
   4 * Copyright (c) 2010 Ira W. Snyder <iws@ovro.caltech.edu>
   5 *
   6 * Lots of inspiration and code was copied from drivers/mfd/sm501.c
   7 *
   8 * This program is free software; you can redistribute it and/or modify it
   9 * under the terms of the GNU General Public License as published by the
  10 * Free Software Foundation; either version 2 of the License, or (at your
  11 * option) any later version.
  12 */
  13
  14#include <linux/kernel.h>
  15#include <linux/module.h>
  16#include <linux/init.h>
  17#include <linux/pci.h>
  18#include <linux/interrupt.h>
  19#include <linux/delay.h>
  20#include <linux/platform_device.h>
  21#include <linux/slab.h>
  22#include <linux/mfd/core.h>
  23
  24#include <linux/mfd/janz.h>
  25
  26#define DRV_NAME "janz-cmodio"
  27
  28/* Size of each MODULbus module in PCI BAR4 */
  29#define CMODIO_MODULBUS_SIZE    0x200
  30
  31/* Maximum number of MODULbus modules on a CMOD-IO carrier board */
  32#define CMODIO_MAX_MODULES      4
  33
  34/* Module Parameters */
  35static unsigned int num_modules = CMODIO_MAX_MODULES;
  36static char *modules[CMODIO_MAX_MODULES] = {
  37        "empty", "empty", "empty", "empty",
  38};
  39
  40module_param_array(modules, charp, &num_modules, S_IRUGO);
  41MODULE_PARM_DESC(modules, "MODULbus modules attached to the carrier board");
  42
  43/* Unique Device Id */
  44static unsigned int cmodio_id;
  45
  46struct cmodio_device {
  47        /* Parent PCI device */
  48        struct pci_dev *pdev;
  49
  50        /* PLX control registers */
  51        struct janz_cmodio_onboard_regs __iomem *ctrl;
  52
  53        /* hex switch position */
  54        u8 hex;
  55
  56        /* mfd-core API */
  57        struct mfd_cell cells[CMODIO_MAX_MODULES];
  58        struct resource resources[3 * CMODIO_MAX_MODULES];
  59        struct janz_platform_data pdata[CMODIO_MAX_MODULES];
  60};
  61
  62/*
  63 * Subdevices using the mfd-core API
  64 */
  65
  66static int cmodio_setup_subdevice(struct cmodio_device *priv,
  67                                            char *name, unsigned int devno,
  68                                            unsigned int modno)
  69{
  70        struct janz_platform_data *pdata;
  71        struct mfd_cell *cell;
  72        struct resource *res;
  73        struct pci_dev *pci;
  74
  75        pci = priv->pdev;
  76        cell = &priv->cells[devno];
  77        res = &priv->resources[devno * 3];
  78        pdata = &priv->pdata[devno];
  79
  80        cell->name = name;
  81        cell->resources = res;
  82        cell->num_resources = 3;
  83
  84        /* Setup the subdevice ID -- must be unique */
  85        cell->id = cmodio_id++;
  86
  87        /* Add platform data */
  88        pdata->modno = modno;
  89        cell->platform_data = pdata;
  90        cell->pdata_size = sizeof(*pdata);
  91
  92        /* MODULbus registers -- PCI BAR3 is big-endian MODULbus access */
  93        res->flags = IORESOURCE_MEM;
  94        res->parent = &pci->resource[3];
  95        res->start = pci->resource[3].start + (CMODIO_MODULBUS_SIZE * modno);
  96        res->end = res->start + CMODIO_MODULBUS_SIZE - 1;
  97        res++;
  98
  99        /* PLX Control Registers -- PCI BAR4 is interrupt and other registers */
 100        res->flags = IORESOURCE_MEM;
 101        res->parent = &pci->resource[4];
 102        res->start = pci->resource[4].start;
 103        res->end = pci->resource[4].end;
 104        res++;
 105
 106        /*
 107         * IRQ
 108         *
 109         * The start and end fields are used as an offset to the irq_base
 110         * parameter passed into the mfd_add_devices() function call. All
 111         * devices share the same IRQ.
 112         */
 113        res->flags = IORESOURCE_IRQ;
 114        res->parent = NULL;
 115        res->start = 0;
 116        res->end = 0;
 117        res++;
 118
 119        return 0;
 120}
 121
 122/* Probe each submodule using kernel parameters */
 123static int cmodio_probe_submodules(struct cmodio_device *priv)
 124{
 125        struct pci_dev *pdev = priv->pdev;
 126        unsigned int num_probed = 0;
 127        char *name;
 128        int i;
 129
 130        for (i = 0; i < num_modules; i++) {
 131                name = modules[i];
 132                if (!strcmp(name, "") || !strcmp(name, "empty"))
 133                        continue;
 134
 135                dev_dbg(&priv->pdev->dev, "MODULbus %d: name %s\n", i, name);
 136                cmodio_setup_subdevice(priv, name, num_probed, i);
 137                num_probed++;
 138        }
 139
 140        /* print an error message if no modules were probed */
 141        if (num_probed == 0) {
 142                dev_err(&priv->pdev->dev, "no MODULbus modules specified, "
 143                                          "please set the ``modules'' kernel "
 144                                          "parameter according to your "
 145                                          "hardware configuration\n");
 146                return -ENODEV;
 147        }
 148
 149        return mfd_add_devices(&pdev->dev, 0, priv->cells,
 150                               num_probed, NULL, pdev->irq, NULL);
 151}
 152
 153/*
 154 * SYSFS Attributes
 155 */
 156
 157static ssize_t mbus_show(struct device *dev, struct device_attribute *attr,
 158                         char *buf)
 159{
 160        struct cmodio_device *priv = dev_get_drvdata(dev);
 161
 162        return snprintf(buf, PAGE_SIZE, "%x\n", priv->hex);
 163}
 164
 165static DEVICE_ATTR(modulbus_number, S_IRUGO, mbus_show, NULL);
 166
 167static struct attribute *cmodio_sysfs_attrs[] = {
 168        &dev_attr_modulbus_number.attr,
 169        NULL,
 170};
 171
 172static const struct attribute_group cmodio_sysfs_attr_group = {
 173        .attrs = cmodio_sysfs_attrs,
 174};
 175
 176/*
 177 * PCI Driver
 178 */
 179
 180static int cmodio_pci_probe(struct pci_dev *dev,
 181                                      const struct pci_device_id *id)
 182{
 183        struct cmodio_device *priv;
 184        int ret;
 185
 186        priv = devm_kzalloc(&dev->dev, sizeof(*priv), GFP_KERNEL);
 187        if (!priv) {
 188                dev_err(&dev->dev, "unable to allocate private data\n");
 189                return -ENOMEM;
 190        }
 191
 192        pci_set_drvdata(dev, priv);
 193        priv->pdev = dev;
 194
 195        /* Hardware Initialization */
 196        ret = pci_enable_device(dev);
 197        if (ret) {
 198                dev_err(&dev->dev, "unable to enable device\n");
 199                return ret;
 200        }
 201
 202        pci_set_master(dev);
 203        ret = pci_request_regions(dev, DRV_NAME);
 204        if (ret) {
 205                dev_err(&dev->dev, "unable to request regions\n");
 206                goto out_pci_disable_device;
 207        }
 208
 209        /* Onboard configuration registers */
 210        priv->ctrl = pci_ioremap_bar(dev, 4);
 211        if (!priv->ctrl) {
 212                dev_err(&dev->dev, "unable to remap onboard regs\n");
 213                ret = -ENOMEM;
 214                goto out_pci_release_regions;
 215        }
 216
 217        /* Read the hex switch on the carrier board */
 218        priv->hex = ioread8(&priv->ctrl->int_enable);
 219
 220        /* Add the MODULbus number (hex switch value) to the device's sysfs */
 221        ret = sysfs_create_group(&dev->dev.kobj, &cmodio_sysfs_attr_group);
 222        if (ret) {
 223                dev_err(&dev->dev, "unable to create sysfs attributes\n");
 224                goto out_unmap_ctrl;
 225        }
 226
 227        /*
 228         * Disable all interrupt lines, each submodule will enable its
 229         * own interrupt line if needed
 230         */
 231        iowrite8(0xf, &priv->ctrl->int_disable);
 232
 233        /* Register drivers for all submodules */
 234        ret = cmodio_probe_submodules(priv);
 235        if (ret) {
 236                dev_err(&dev->dev, "unable to probe submodules\n");
 237                goto out_sysfs_remove_group;
 238        }
 239
 240        return 0;
 241
 242out_sysfs_remove_group:
 243        sysfs_remove_group(&dev->dev.kobj, &cmodio_sysfs_attr_group);
 244out_unmap_ctrl:
 245        iounmap(priv->ctrl);
 246out_pci_release_regions:
 247        pci_release_regions(dev);
 248out_pci_disable_device:
 249        pci_disable_device(dev);
 250
 251        return ret;
 252}
 253
 254static void cmodio_pci_remove(struct pci_dev *dev)
 255{
 256        struct cmodio_device *priv = pci_get_drvdata(dev);
 257
 258        mfd_remove_devices(&dev->dev);
 259        sysfs_remove_group(&dev->dev.kobj, &cmodio_sysfs_attr_group);
 260        iounmap(priv->ctrl);
 261        pci_release_regions(dev);
 262        pci_disable_device(dev);
 263}
 264
 265#define PCI_VENDOR_ID_JANZ              0x13c3
 266
 267/* The list of devices that this module will support */
 268static DEFINE_PCI_DEVICE_TABLE(cmodio_pci_ids) = {
 269        { PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9030, PCI_VENDOR_ID_JANZ, 0x0101 },
 270        { PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9050, PCI_VENDOR_ID_JANZ, 0x0100 },
 271        { 0, }
 272};
 273MODULE_DEVICE_TABLE(pci, cmodio_pci_ids);
 274
 275static struct pci_driver cmodio_pci_driver = {
 276        .name     = DRV_NAME,
 277        .id_table = cmodio_pci_ids,
 278        .probe    = cmodio_pci_probe,
 279        .remove   = cmodio_pci_remove,
 280};
 281
 282module_pci_driver(cmodio_pci_driver);
 283
 284MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>");
 285MODULE_DESCRIPTION("Janz CMOD-IO PCI MODULbus Carrier Board Driver");
 286MODULE_LICENSE("GPL");
 287
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