FUSB302 code
/*
* File: fusb30x_driver.c
* Company: Fairchild Semiconductor
*
* Created on September 2, 2015, 10:22 AM
*/
/* Standard Linux includes */
#include <linux/init.h> // __init, __initdata, etc
#include <linux/module.h> // Needed to be a module
#include <linux/kernel.h> // Needed to be a kernel module
#include <linux/i2c.h> // I2C functionality
#include <linux/slab.h> // devm_kzalloc
#include <linux/types.h> // Kernel datatypes
#include <linux/errno.h> // EINVAL, ERANGE, etc
#include <linux/of_device.h> // Device tree functionality
/* Driver-specific includes */
#include "fusb30x_global.h" // Driver-specific structures/types
#include "platform_helpers.h" // I2C R/W, GPIO, misc, etc
#include "../core/core.h" // GetDeviceTypeCStatus
#ifdef FSC_DEBUG
#include "dfs.h"
#endif // FSC_DEBUG
#include "fusb30x_driver.h"
/******************************************************************************
* Driver functions
******************************************************************************/
static int __init fusb30x_init(void)
{
pr_debug("FUSB %s - Start driver initialization...\n", __func__);
return i2c_add_driver(&fusb30x_driver);
}
static void __exit fusb30x_exit(void)
{
i2c_del_driver(&fusb30x_driver);
pr_debug("FUSB %s - Driver deleted...\n", __func__);
}
static int fusb302_i2c_resume(struct device* dev)
{
struct fusb30x_chip *chip;
struct i2c_client *client = to_i2c_client(dev);
if (client) {
chip = i2c_get_clientdata(client);
if (chip)
up(&chip->suspend_lock);
}
return 0;
}
static int fusb302_i2c_suspend(struct device* dev)
{
struct fusb30x_chip* chip;
struct i2c_client* client = to_i2c_client(dev);
if (client) {
chip = i2c_get_clientdata(client);
if (chip)
down(&chip->suspend_lock);
}
return 0;
}
static int fusb30x_probe (struct i2c_client* client,
const struct i2c_device_id* id)
{
int ret = 0;
struct fusb30x_chip* chip;
struct i2c_adapter* adapter;
if (!client)
{
pr_err("FUSB %s - Error: Client structure is NULL!\n", __func__);
return -EINVAL;
}
dev_info(&client->dev, "%s\n", __func__);
/* Make sure probe was called on a compatible device */
if (!of_match_device(fusb30x_dt_match, &client->dev))
{
dev_err(&client->dev, "FUSB %s - Error: Device tree mismatch!\n", __func__);
return -EINVAL;
}
pr_debug("FUSB %s - Device tree matched!\n", __func__);
/* Allocate space for our chip structure (devm_* is managed by the device) */
chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
if (!chip)
{
dev_err(&client->dev, "FUSB %s - Error: Unable to allocate memory for g_chip!\n", __func__);
return -ENOMEM;
}
chip->client = client; // Assign our client handle to our chip
fusb30x_SetChip(chip); // Set our global chip's address to the newly allocated memory
pr_debug("FUSB %s - Chip structure is set! Chip: %p ... g_chip: %p\n", __func__, chip, fusb30x_GetChip());
/* Initialize the chip lock */
mutex_init(&chip->lock);
/* Initialize the chip's data members */
fusb_InitChipData();
pr_debug("FUSB %s - Chip struct data initialized!\n", __func__);
/* Verify that the system has our required I2C/SMBUS functionality (see <linux/i2c.h> for definitions) */
adapter = to_i2c_adapter(client->dev.parent);
if (i2c_check_functionality(adapter, FUSB30X_I2C_SMBUS_BLOCK_REQUIRED_FUNC))
{
chip->use_i2c_blocks = true;
}
else
{
// If the platform doesn't support block reads, try with block writes and single reads (works with eg. RPi)
// NOTE: It is likely that this may result in non-standard behavior, but will often be 'close enough' to work for most things
dev_warn(&client->dev, "FUSB %s - Warning: I2C/SMBus block read/write functionality not supported, checking single-read mode...\n", __func__);
if (!i2c_check_functionality(adapter, FUSB30X_I2C_SMBUS_REQUIRED_FUNC))
{
dev_err(&client->dev, "FUSB %s - Error: Required I2C/SMBus functionality not supported!\n", __func__);
dev_err(&client->dev, "FUSB %s - I2C Supported Functionality Mask: 0x%x\n", __func__, i2c_get_functionality(adapter));
return -EIO;
}
}
pr_debug("FUSB %s - I2C Functionality check passed! Block reads: %s\n", __func__, chip->use_i2c_blocks ? "YES" : "NO");
/* Assign our struct as the client's driverdata */
i2c_set_clientdata(client, chip);
pr_debug("FUSB %s - I2C client data set!\n", __func__);
/* Verify that our device exists and that it's what we expect */
if (!fusb_IsDeviceValid())
{
dev_err(&client->dev, "FUSB %s - Error: Unable to communicate with device!\n", __func__);
return -EIO;
}
pr_debug("FUSB %s - Device check passed!\n", __func__);
/* reset fusb302*/
fusb_reset();
/* Initialize semaphore*/
sema_init(&chip->suspend_lock, 1);
/* Initialize the platform's GPIO pins and IRQ */
ret = fusb_InitializeGPIO();
if (ret)
{
dev_err(&client->dev, "FUSB %s - Error: Unable to initialize GPIO!\n", __func__);
return ret;
}
pr_debug("FUSB %s - GPIO initialized!\n", __func__);
/* Initialize sysfs file accessors */
fusb_Sysfs_Init();
pr_debug("FUSB %s - Sysfs nodes created!\n", __func__);
#ifdef FSC_DEBUG
/* Initialize debugfs file accessors */
fusb_DFS_Init();
pr_debug("FUSB %s - DebugFS nodes created!\n", __func__);
#endif // FSC_DEBUG
/* Enable interrupts after successful core/GPIO initialization */
ret = fusb_EnableInterrupts();
if (ret)
{
dev_err(&client->dev, "FUSB %s - Error: Unable to enable interrupts! Error code: %d\n", __func__, ret);
return -EIO;
}
/* Initialize the core and enable the state machine (NOTE: timer and GPIO must be initialized by now)
* Interrupt must be enabled before starting 302 initialization */
fusb_InitializeCore();
pr_debug("FUSB %s - Core is initialized!\n", __func__);
dev_info(&client->dev, "FUSB %s - FUSB30X Driver loaded successfully!\n", __func__);
return ret;
}
static int fusb30x_remove(struct i2c_client* client)
{
pr_debug("FUSB %s - Removing fusb30x device!\n", __func__);
#ifdef FSC_DEBUG
/* Remove debugfs file accessors */
fusb_DFS_Cleanup();
pr_debug("FUSB %s - DebugFS nodes removed.\n", __func__);
#endif // FSC_DEBUG
fusb_GPIO_Cleanup();
pr_debug("FUSB %s - FUSB30x device removed from driver...\n", __func__);
return 0;
}
static void fusb30x_shutdown(struct i2c_client *client)
{
fusb_reset();
pr_debug("FUSB %s - fusb302 shutdown\n", __func__);
}
/*******************************************************************************
* Driver macros
******************************************************************************/
module_init(fusb30x_init); // Defines the module's entrance function
module_exit(fusb30x_exit); // Defines the module's exit function
MODULE_LICENSE("GPL"); // Exposed on call to modinfo
MODULE_DESCRIPTION("Fairchild FUSB30x Driver"); // Exposed on call to modinfo
MODULE_AUTHOR("Fairchild"); // Exposed on call to modinfo
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