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Writing Device Drivers
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Part I Designing Device Drivers for the Solaris Platform

1.  Overview of Solaris Device Drivers

2.  Solaris Kernel and Device Tree

3.  Multithreading

4.  Properties

5.  Managing Events and Queueing Tasks

6.  Driver Autoconfiguration

7.  Device Access: Programmed I/O

8.  Interrupt Handlers

9.  Direct Memory Access (DMA)

10.  Mapping Device and Kernel Memory

11.  Device Context Management

12.  Power Management

13.  Hardening Solaris Drivers

14.  Layered Driver Interface (LDI)

Part II Designing Specific Kinds of Device Drivers

15.  Drivers for Character Devices

Overview of the Character Driver Structure

Character Device Autoconfiguration

Device Access (Character Drivers)

open() Entry Point (Character Drivers)

close() Entry Point (Character Drivers)

I/O Request Handling

User Addresses

Vectored I/O

Differences Between Synchronous and Asynchronous I/O

Data Transfer Methods

Programmed I/O Transfers

DMA Transfers (Synchronous)

DMA Transfers (Asynchronous)

minphys() Entry Point

strategy() Entry Point

Mapping Device Memory

Multiplexing I/O on File Descriptors

Miscellaneous I/O Control

ioctl() Entry Point (Character Drivers)

I/O Control Support for 64-Bit Capable Device Drivers

Handling copyout() Overflow

32-bit and 64-bit Data Structure Macros

How Do the Structure Macros Work?

When to Use Structure Macros

Declaring and Initializing Structure Handles

Operations on Structure Handles

Other Operations

16.  Drivers for Block Devices

17.  SCSI Target Drivers

18.  SCSI Host Bus Adapter Drivers

19.  Drivers for Network Devices

20.  USB Drivers

Part III Building a Device Driver

21.  Compiling, Loading, Packaging, and Testing Drivers

22.  Debugging, Testing, and Tuning Device Drivers

23.  Recommended Coding Practices

Part IV Appendixes

A.  Hardware Overview

B.  Summary of Solaris DDI/DKI Services

C.  Making a Device Driver 64-Bit Ready

D.  Console Frame Buffer Drivers


Character Device Autoconfiguration

The attach(9E) routine should perform the common initialization tasks that all devices require, such as:

See attach() Entry Point for code examples of these tasks.

Character device drivers create minor nodes of type S_IFCHR. A minor node of S_IFCHR causes a character special file that represents the node to eventually appear in the /devices hierarchy.

The following example shows a typical attach(9E) routine for character drivers. Properties that are associated with the device are commonly declared in an attach() routine. This example uses a predefined Size property. Size is the equivalent of the Nblocks property for getting the size of partition in a block device. If, for example, you are doing character I/O on a disk device, you might use Size to get the size of a partition. Since Size is a 64-bit property, you must use a 64-bit property interface. In this case, you use ddi_prop_update_int64(9F). See Device Properties for more information about properties.

Example 15-1 Character Driver attach() Routine

static int
xxattach(dev_info_t *dip, ddi_attach_cmd_t cmd)
  int instance = ddi_get_instance(dip);
  switch (cmd) {
  case DDI_ATTACH:
       * Allocate a state structure and initialize it.
       * Map the device's registers.
       * Add the device driver's interrupt handler(s).
       * Initialize any mutexes and condition variables.
       * Create power manageable components.
       * Create the device's minor node. Note that the node_type
       * argument is set to DDI_NT_TAPE.
       if (ddi_create_minor_node(dip, minor_name, S_IFCHR,
           instance, DDI_NT_TAPE, 0) == DDI_FAILURE) {
           /* Free resources allocated so far. */
           /* Remove any previously allocated minor nodes. */
           ddi_remove_minor_node(dip, NULL);
           return (DDI_FAILURE);
       * Create driver properties like "Size." Use "Size" 
       * instead of "size" to ensure the property works 
       * for large bytecounts.
       xsp->Size = size_of_device_in_bytes;
       maj_number = ddi_driver_major(dip);
       if (ddi_prop_update_int64(makedevice(maj_number, instance), 
           dip, "Size", xsp->Size) != DDI_PROP_SUCCESS) {
           cmn_err(CE_CONT, "%s: cannot create Size property\n",
               /* Free resources allocated so far. */
           return (DDI_FAILURE);
      /* ... */
      return (DDI_SUCCESS);    
      /* See the "Power Management" chapter in this book. */
      return (DDI_FAILURE);