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authorYuval Adam <_@yuv.al>2017-08-30 08:25:59 +0000
committerYuval Adam <_@yuv.al>2017-08-30 08:25:59 +0000
commit8e4bff4cab0ddac6060645b0715210484d02ff40 (patch)
tree3a5c3024371a04692a3a6d9974d001cdff8ebf84 /drivers/staging/comedi/drivers.c
Initial file dump from open source releaseHEADmaster
Diffstat (limited to 'drivers/staging/comedi/drivers.c')
-rw-r--r--drivers/staging/comedi/drivers.c569
1 files changed, 569 insertions, 0 deletions
diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c
new file mode 100644
index 00000000..4a2b0427
--- /dev/null
+++ b/drivers/staging/comedi/drivers.c
@@ -0,0 +1,569 @@
+/*
+ module/drivers.c
+ functions for manipulating drivers
+
+ COMEDI - Linux Control and Measurement Device Interface
+ Copyright (C) 1997-2000 David A. Schleef <ds@schleef.org>
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kconfig.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/fcntl.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/highmem.h> /* for SuSE brokenness */
+#include <linux/vmalloc.h>
+#include <linux/cdev.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+
+#include "comedidev.h"
+#include "comedi_internal.h"
+
+struct comedi_driver *comedi_drivers;
+
+int comedi_set_hw_dev(struct comedi_device *dev, struct device *hw_dev)
+{
+ if (hw_dev == dev->hw_dev)
+ return 0;
+ if (dev->hw_dev != NULL)
+ return -EEXIST;
+ dev->hw_dev = get_device(hw_dev);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(comedi_set_hw_dev);
+
+static void comedi_clear_hw_dev(struct comedi_device *dev)
+{
+ put_device(dev->hw_dev);
+ dev->hw_dev = NULL;
+}
+
+int comedi_alloc_subdevices(struct comedi_device *dev, int num_subdevices)
+{
+ struct comedi_subdevice *s;
+ int i;
+
+ if (num_subdevices < 1)
+ return -EINVAL;
+
+ s = kcalloc(num_subdevices, sizeof(*s), GFP_KERNEL);
+ if (!s)
+ return -ENOMEM;
+ dev->subdevices = s;
+ dev->n_subdevices = num_subdevices;
+
+ for (i = 0; i < num_subdevices; ++i) {
+ s = &dev->subdevices[i];
+ s->device = dev;
+ s->index = i;
+ s->async_dma_dir = DMA_NONE;
+ spin_lock_init(&s->spin_lock);
+ s->minor = -1;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(comedi_alloc_subdevices);
+
+void comedi_spriv_free(struct comedi_device *dev, int subdev_num)
+{
+ struct comedi_subdevice *s;
+
+ if (dev->subdevices && subdev_num < dev->n_subdevices) {
+ s = &dev->subdevices[subdev_num];
+ kfree(s->private);
+ s->private = NULL;
+ }
+}
+EXPORT_SYMBOL_GPL(comedi_spriv_free);
+
+static void cleanup_device(struct comedi_device *dev)
+{
+ int i;
+ struct comedi_subdevice *s;
+
+ if (dev->subdevices) {
+ for (i = 0; i < dev->n_subdevices; i++) {
+ s = &dev->subdevices[i];
+ comedi_free_subdevice_minor(s);
+ if (s->async) {
+ comedi_buf_alloc(dev, s, 0);
+ kfree(s->async);
+ }
+ }
+ kfree(dev->subdevices);
+ dev->subdevices = NULL;
+ dev->n_subdevices = 0;
+ }
+ kfree(dev->private);
+ dev->private = NULL;
+ dev->driver = NULL;
+ dev->board_name = NULL;
+ dev->board_ptr = NULL;
+ dev->iobase = 0;
+ dev->iolen = 0;
+ dev->ioenabled = false;
+ dev->irq = 0;
+ dev->read_subdev = NULL;
+ dev->write_subdev = NULL;
+ dev->open = NULL;
+ dev->close = NULL;
+ comedi_clear_hw_dev(dev);
+}
+
+void comedi_device_detach(struct comedi_device *dev)
+{
+ dev->attached = false;
+ if (dev->driver)
+ dev->driver->detach(dev);
+ cleanup_device(dev);
+}
+
+static int poll_invalid(struct comedi_device *dev, struct comedi_subdevice *s)
+{
+ return -EINVAL;
+}
+
+int insn_inval(struct comedi_device *dev, struct comedi_subdevice *s,
+ struct comedi_insn *insn, unsigned int *data)
+{
+ return -EINVAL;
+}
+
+static int insn_rw_emulate_bits(struct comedi_device *dev,
+ struct comedi_subdevice *s,
+ struct comedi_insn *insn, unsigned int *data)
+{
+ struct comedi_insn new_insn;
+ int ret;
+ static const unsigned channels_per_bitfield = 32;
+
+ unsigned chan = CR_CHAN(insn->chanspec);
+ const unsigned base_bitfield_channel =
+ (chan < channels_per_bitfield) ? 0 : chan;
+ unsigned int new_data[2];
+ memset(new_data, 0, sizeof(new_data));
+ memset(&new_insn, 0, sizeof(new_insn));
+ new_insn.insn = INSN_BITS;
+ new_insn.chanspec = base_bitfield_channel;
+ new_insn.n = 2;
+ new_insn.subdev = insn->subdev;
+
+ if (insn->insn == INSN_WRITE) {
+ if (!(s->subdev_flags & SDF_WRITABLE))
+ return -EINVAL;
+ new_data[0] = 1 << (chan - base_bitfield_channel); /* mask */
+ new_data[1] = data[0] ? (1 << (chan - base_bitfield_channel))
+ : 0; /* bits */
+ }
+
+ ret = s->insn_bits(dev, s, &new_insn, new_data);
+ if (ret < 0)
+ return ret;
+
+ if (insn->insn == INSN_READ)
+ data[0] = (new_data[1] >> (chan - base_bitfield_channel)) & 1;
+
+ return 1;
+}
+
+static int __comedi_device_postconfig_async(struct comedi_device *dev,
+ struct comedi_subdevice *s)
+{
+ struct comedi_async *async;
+ unsigned int buf_size;
+ int ret;
+
+ if ((s->subdev_flags & (SDF_CMD_READ | SDF_CMD_WRITE)) == 0) {
+ dev_warn(dev->class_dev,
+ "async subdevices must support SDF_CMD_READ or SDF_CMD_WRITE\n");
+ return -EINVAL;
+ }
+ if (!s->do_cmdtest) {
+ dev_warn(dev->class_dev,
+ "async subdevices must have a do_cmdtest() function\n");
+ return -EINVAL;
+ }
+
+ async = kzalloc(sizeof(*async), GFP_KERNEL);
+ if (!async)
+ return -ENOMEM;
+
+ init_waitqueue_head(&async->wait_head);
+ async->subdevice = s;
+ s->async = async;
+
+ async->max_bufsize = comedi_default_buf_maxsize_kb * 1024;
+ buf_size = comedi_default_buf_size_kb * 1024;
+ if (buf_size > async->max_bufsize)
+ buf_size = async->max_bufsize;
+
+ if (comedi_buf_alloc(dev, s, buf_size) < 0) {
+ dev_warn(dev->class_dev, "Buffer allocation failed\n");
+ return -ENOMEM;
+ }
+ if (s->buf_change) {
+ ret = s->buf_change(dev, s, buf_size);
+ if (ret < 0)
+ return ret;
+ }
+
+ comedi_alloc_subdevice_minor(s);
+
+ return 0;
+}
+
+static int __comedi_device_postconfig(struct comedi_device *dev)
+{
+ struct comedi_subdevice *s;
+ int ret;
+ int i;
+
+ for (i = 0; i < dev->n_subdevices; i++) {
+ s = &dev->subdevices[i];
+
+ if (s->type == COMEDI_SUBD_UNUSED)
+ continue;
+
+ if (s->len_chanlist == 0)
+ s->len_chanlist = 1;
+
+ if (s->do_cmd) {
+ ret = __comedi_device_postconfig_async(dev, s);
+ if (ret)
+ return ret;
+ }
+
+ if (!s->range_table && !s->range_table_list)
+ s->range_table = &range_unknown;
+
+ if (!s->insn_read && s->insn_bits)
+ s->insn_read = insn_rw_emulate_bits;
+ if (!s->insn_write && s->insn_bits)
+ s->insn_write = insn_rw_emulate_bits;
+
+ if (!s->insn_read)
+ s->insn_read = insn_inval;
+ if (!s->insn_write)
+ s->insn_write = insn_inval;
+ if (!s->insn_bits)
+ s->insn_bits = insn_inval;
+ if (!s->insn_config)
+ s->insn_config = insn_inval;
+
+ if (!s->poll)
+ s->poll = poll_invalid;
+ }
+
+ return 0;
+}
+
+/* do a little post-config cleanup */
+static int comedi_device_postconfig(struct comedi_device *dev)
+{
+ int ret;
+
+ ret = __comedi_device_postconfig(dev);
+ if (ret < 0)
+ return ret;
+ smp_wmb();
+ dev->attached = true;
+ return 0;
+}
+
+/*
+ * Generic recognize function for drivers that register their supported
+ * board names.
+ *
+ * 'driv->board_name' points to a 'const char *' member within the
+ * zeroth element of an array of some private board information
+ * structure, say 'struct foo_board' containing a member 'const char
+ * *board_name' that is initialized to point to a board name string that
+ * is one of the candidates matched against this function's 'name'
+ * parameter.
+ *
+ * 'driv->offset' is the size of the private board information
+ * structure, say 'sizeof(struct foo_board)', and 'driv->num_names' is
+ * the length of the array of private board information structures.
+ *
+ * If one of the board names in the array of private board information
+ * structures matches the name supplied to this function, the function
+ * returns a pointer to the pointer to the board name, otherwise it
+ * returns NULL. The return value ends up in the 'board_ptr' member of
+ * a 'struct comedi_device' that the low-level comedi driver's
+ * 'attach()' hook can convert to a point to a particular element of its
+ * array of private board information structures by subtracting the
+ * offset of the member that points to the board name. (No subtraction
+ * is required if the board name pointer is the first member of the
+ * private board information structure, which is generally the case.)
+ */
+static void *comedi_recognize(struct comedi_driver *driv, const char *name)
+{
+ char **name_ptr = (char **)driv->board_name;
+ int i;
+
+ for (i = 0; i < driv->num_names; i++) {
+ if (strcmp(*name_ptr, name) == 0)
+ return name_ptr;
+ name_ptr = (void *)name_ptr + driv->offset;
+ }
+
+ return NULL;
+}
+
+static void comedi_report_boards(struct comedi_driver *driv)
+{
+ unsigned int i;
+ const char *const *name_ptr;
+
+ pr_info("comedi: valid board names for %s driver are:\n",
+ driv->driver_name);
+
+ name_ptr = driv->board_name;
+ for (i = 0; i < driv->num_names; i++) {
+ pr_info(" %s\n", *name_ptr);
+ name_ptr = (const char **)((char *)name_ptr + driv->offset);
+ }
+
+ if (driv->num_names == 0)
+ pr_info(" %s\n", driv->driver_name);
+}
+
+/**
+ * __comedi_request_region() - Request an I/O reqion for a legacy driver.
+ * @dev: comedi_device struct
+ * @start: base address of the I/O reqion
+ * @len: length of the I/O region
+ */
+int __comedi_request_region(struct comedi_device *dev,
+ unsigned long start, unsigned long len)
+{
+ if (!start) {
+ dev_warn(dev->class_dev,
+ "%s: a I/O base address must be specified\n",
+ dev->board_name);
+ return -EINVAL;
+ }
+
+ if (!request_region(start, len, dev->board_name)) {
+ dev_warn(dev->class_dev, "%s: I/O port conflict (%#lx,%lu)\n",
+ dev->board_name, start, len);
+ return -EIO;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(__comedi_request_region);
+
+/**
+ * comedi_request_region() - Request an I/O reqion for a legacy driver.
+ * @dev: comedi_device struct
+ * @start: base address of the I/O reqion
+ * @len: length of the I/O region
+ */
+int comedi_request_region(struct comedi_device *dev,
+ unsigned long start, unsigned long len)
+{
+ int ret;
+
+ ret = __comedi_request_region(dev, start, len);
+ if (ret == 0) {
+ dev->iobase = start;
+ dev->iolen = len;
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(comedi_request_region);
+
+/**
+ * comedi_legacy_detach() - A generic (*detach) function for legacy drivers.
+ * @dev: comedi_device struct
+ */
+void comedi_legacy_detach(struct comedi_device *dev)
+{
+ if (dev->irq) {
+ free_irq(dev->irq, dev);
+ dev->irq = 0;
+ }
+ if (dev->iobase && dev->iolen) {
+ release_region(dev->iobase, dev->iolen);
+ dev->iobase = 0;
+ dev->iolen = 0;
+ }
+}
+EXPORT_SYMBOL_GPL(comedi_legacy_detach);
+
+int comedi_device_attach(struct comedi_device *dev, struct comedi_devconfig *it)
+{
+ struct comedi_driver *driv;
+ int ret;
+
+ if (dev->attached)
+ return -EBUSY;
+
+ for (driv = comedi_drivers; driv; driv = driv->next) {
+ if (!try_module_get(driv->module))
+ continue;
+ if (driv->num_names) {
+ dev->board_ptr = comedi_recognize(driv, it->board_name);
+ if (dev->board_ptr)
+ break;
+ } else if (strcmp(driv->driver_name, it->board_name) == 0)
+ break;
+ module_put(driv->module);
+ }
+ if (driv == NULL) {
+ /* recognize has failed if we get here */
+ /* report valid board names before returning error */
+ for (driv = comedi_drivers; driv; driv = driv->next) {
+ if (!try_module_get(driv->module))
+ continue;
+ comedi_report_boards(driv);
+ module_put(driv->module);
+ }
+ return -EIO;
+ }
+ if (driv->attach == NULL) {
+ /* driver does not support manual configuration */
+ dev_warn(dev->class_dev,
+ "driver '%s' does not support attach using comedi_config\n",
+ driv->driver_name);
+ module_put(driv->module);
+ return -ENOSYS;
+ }
+ /* initialize dev->driver here so
+ * comedi_error() can be called from attach */
+ dev->driver = driv;
+ dev->board_name = dev->board_ptr ? *(const char **)dev->board_ptr
+ : dev->driver->driver_name;
+ ret = driv->attach(dev, it);
+ if (ret >= 0)
+ ret = comedi_device_postconfig(dev);
+ if (ret < 0) {
+ comedi_device_detach(dev);
+ module_put(driv->module);
+ }
+ /* On success, the driver module count has been incremented. */
+ return ret;
+}
+
+int comedi_auto_config(struct device *hardware_device,
+ struct comedi_driver *driver, unsigned long context)
+{
+ struct comedi_device *dev;
+ int ret;
+
+ if (!hardware_device) {
+ pr_warn("BUG! comedi_auto_config called with NULL hardware_device\n");
+ return -EINVAL;
+ }
+ if (!driver) {
+ dev_warn(hardware_device,
+ "BUG! comedi_auto_config called with NULL comedi driver\n");
+ return -EINVAL;
+ }
+
+ if (!driver->auto_attach) {
+ dev_warn(hardware_device,
+ "BUG! comedi driver '%s' has no auto_attach handler\n",
+ driver->driver_name);
+ return -EINVAL;
+ }
+
+ dev = comedi_alloc_board_minor(hardware_device);
+ if (IS_ERR(dev))
+ return PTR_ERR(dev);
+ /* Note: comedi_alloc_board_minor() locked dev->mutex. */
+
+ dev->driver = driver;
+ dev->board_name = dev->driver->driver_name;
+ ret = driver->auto_attach(dev, context);
+ if (ret >= 0)
+ ret = comedi_device_postconfig(dev);
+ if (ret < 0)
+ comedi_device_detach(dev);
+ mutex_unlock(&dev->mutex);
+
+ if (ret < 0)
+ comedi_release_hardware_device(hardware_device);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(comedi_auto_config);
+
+void comedi_auto_unconfig(struct device *hardware_device)
+{
+ if (hardware_device == NULL)
+ return;
+ comedi_release_hardware_device(hardware_device);
+}
+EXPORT_SYMBOL_GPL(comedi_auto_unconfig);
+
+int comedi_driver_register(struct comedi_driver *driver)
+{
+ driver->next = comedi_drivers;
+ comedi_drivers = driver;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(comedi_driver_register);
+
+int comedi_driver_unregister(struct comedi_driver *driver)
+{
+ struct comedi_driver *prev;
+ int i;
+
+ /* check for devices using this driver */
+ for (i = 0; i < COMEDI_NUM_BOARD_MINORS; i++) {
+ struct comedi_device *dev = comedi_dev_from_minor(i);
+
+ if (!dev)
+ continue;
+
+ mutex_lock(&dev->mutex);
+ if (dev->attached && dev->driver == driver) {
+ if (dev->use_count)
+ dev_warn(dev->class_dev,
+ "BUG! detaching device with use_count=%d\n",
+ dev->use_count);
+ comedi_device_detach(dev);
+ }
+ mutex_unlock(&dev->mutex);
+ }
+
+ if (comedi_drivers == driver) {
+ comedi_drivers = driver->next;
+ return 0;
+ }
+
+ for (prev = comedi_drivers; prev->next; prev = prev->next) {
+ if (prev->next == driver) {
+ prev->next = driver->next;
+ return 0;
+ }
+ }
+ return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(comedi_driver_unregister);