209 lines
4.8 KiB
C
209 lines
4.8 KiB
C
/* Copyright (c) 2012-2014, The Linux Foundation. All rights reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 and
|
|
* only version 2 as published by the Free Software Foundation.
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/msm_dsps.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/cdev.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/of_device.h>
|
|
#include <asm/arch_timer.h>
|
|
#include <linux/uaccess.h>
|
|
|
|
#define CLASS_NAME "ssc"
|
|
#define DRV_NAME "sensors"
|
|
#define DRV_VERSION "2.00"
|
|
#ifdef CONFIG_COMPAT
|
|
#define DSPS_IOCTL_READ_SLOW_TIMER32 _IOR(DSPS_IOCTL_MAGIC, 3, compat_uint_t)
|
|
#endif
|
|
|
|
struct sns_ssc_control_s {
|
|
struct class *dev_class;
|
|
dev_t dev_num;
|
|
struct device *dev;
|
|
struct cdev *cdev;
|
|
};
|
|
static struct sns_ssc_control_s sns_ctl;
|
|
|
|
/*
|
|
* Read QTimer clock ticks and scale down to 32KHz clock as used
|
|
* in DSPS
|
|
*/
|
|
static u32 sns_read_qtimer(void)
|
|
{
|
|
u64 val;
|
|
val = arch_counter_get_cntpct();
|
|
/*
|
|
* To convert ticks from 19.2 Mhz clock to 32768 Hz clock:
|
|
* x = (value * 32768) / 19200000
|
|
* This is same as first left shift the value by 4 bits, i.e. mutiply
|
|
* by 16, and then divide by 9375. The latter is preferable since
|
|
* QTimer tick (value) is 56-bit, so (value * 32768) could overflow,
|
|
* while (value * 16) will never do
|
|
*/
|
|
val <<= 4;
|
|
do_div(val, 9375);
|
|
|
|
return (u32)val;
|
|
}
|
|
|
|
static int sensors_ssc_open(struct inode *ip, struct file *fp)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static int sensors_ssc_release(struct inode *inode, struct file *file)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static long sensors_ssc_ioctl(struct file *file,
|
|
unsigned int cmd, unsigned long arg)
|
|
{
|
|
int ret = 0;
|
|
u32 val = 0;
|
|
|
|
switch (cmd) {
|
|
case DSPS_IOCTL_READ_SLOW_TIMER:
|
|
#ifdef CONFIG_COMPAT
|
|
case DSPS_IOCTL_READ_SLOW_TIMER32:
|
|
#endif
|
|
val = sns_read_qtimer();
|
|
ret = put_user(val, (u32 __user *) arg);
|
|
break;
|
|
|
|
default:
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
const struct file_operations sensors_ssc_fops = {
|
|
.owner = THIS_MODULE,
|
|
.open = sensors_ssc_open,
|
|
.release = sensors_ssc_release,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_ioctl = sensors_ssc_ioctl,
|
|
#endif
|
|
.unlocked_ioctl = sensors_ssc_ioctl
|
|
};
|
|
|
|
static int sensors_ssc_probe(struct platform_device *pdev)
|
|
{
|
|
int ret = 0;
|
|
|
|
sns_ctl.dev_class = class_create(THIS_MODULE, CLASS_NAME);
|
|
if (sns_ctl.dev_class == NULL) {
|
|
pr_err("%s: class_create fail.\n", __func__);
|
|
goto res_err;
|
|
}
|
|
|
|
ret = alloc_chrdev_region(&sns_ctl.dev_num, 0, 1, DRV_NAME);
|
|
if (ret) {
|
|
pr_err("%s: alloc_chrdev_region fail.\n", __func__);
|
|
goto alloc_chrdev_region_err;
|
|
}
|
|
|
|
sns_ctl.dev = device_create(sns_ctl.dev_class, NULL,
|
|
sns_ctl.dev_num,
|
|
&sns_ctl, DRV_NAME);
|
|
if (IS_ERR(sns_ctl.dev)) {
|
|
pr_err("%s: device_create fail.\n", __func__);
|
|
goto device_create_err;
|
|
}
|
|
|
|
sns_ctl.cdev = cdev_alloc();
|
|
if (sns_ctl.cdev == NULL) {
|
|
pr_err("%s: cdev_alloc fail.\n", __func__);
|
|
goto cdev_alloc_err;
|
|
}
|
|
cdev_init(sns_ctl.cdev, &sensors_ssc_fops);
|
|
sns_ctl.cdev->owner = THIS_MODULE;
|
|
|
|
ret = cdev_add(sns_ctl.cdev, sns_ctl.dev_num, 1);
|
|
if (ret) {
|
|
pr_err("%s: cdev_add fail.\n", __func__);
|
|
goto cdev_add_err;
|
|
}
|
|
|
|
return 0;
|
|
|
|
cdev_add_err:
|
|
kfree(sns_ctl.cdev);
|
|
cdev_alloc_err:
|
|
device_destroy(sns_ctl.dev_class, sns_ctl.dev_num);
|
|
device_create_err:
|
|
unregister_chrdev_region(sns_ctl.dev_num, 1);
|
|
alloc_chrdev_region_err:
|
|
class_destroy(sns_ctl.dev_class);
|
|
res_err:
|
|
return -ENODEV;
|
|
}
|
|
|
|
static int sensors_ssc_remove(struct platform_device *pdev)
|
|
{
|
|
cdev_del(sns_ctl.cdev);
|
|
kfree(sns_ctl.cdev);
|
|
sns_ctl.cdev = NULL;
|
|
device_destroy(sns_ctl.dev_class, sns_ctl.dev_num);
|
|
unregister_chrdev_region(sns_ctl.dev_num, 1);
|
|
class_destroy(sns_ctl.dev_class);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id msm_ssc_sensors_dt_match[] = {
|
|
{.compatible = "qcom,msm-ssc-sensors"},
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, msm_ssc_sensors_dt_match);
|
|
|
|
static struct platform_driver sensors_ssc_driver = {
|
|
.driver = {
|
|
.name = "sensors-ssc",
|
|
.owner = THIS_MODULE,
|
|
.of_match_table = msm_ssc_sensors_dt_match,
|
|
},
|
|
.probe = sensors_ssc_probe,
|
|
.remove = sensors_ssc_remove,
|
|
};
|
|
|
|
static int __init sensors_ssc_init(void)
|
|
{
|
|
int rc;
|
|
|
|
pr_debug("%s driver version %s.\n", DRV_NAME, DRV_VERSION);
|
|
rc = platform_driver_register(&sensors_ssc_driver);
|
|
if (rc) {
|
|
pr_err("%s: Failed to register sensors ssc driver\n",
|
|
__func__);
|
|
return rc;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __exit sensors_ssc_exit(void)
|
|
{
|
|
platform_driver_unregister(&sensors_ssc_driver);
|
|
}
|
|
|
|
module_init(sensors_ssc_init);
|
|
module_exit(sensors_ssc_exit);
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_DESCRIPTION("Sensors SSC driver");
|