diff options
Diffstat (limited to 'drivers/misc/tegra-throughput.c')
| -rw-r--r-- | drivers/misc/tegra-throughput.c | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/drivers/misc/tegra-throughput.c b/drivers/misc/tegra-throughput.c new file mode 100644 index 000000000000..d491ef8c06cf --- /dev/null +++ b/drivers/misc/tegra-throughput.c @@ -0,0 +1,242 @@ +/* + * drivers/misc/throughput.c + * + * Copyright (C) 2012, NVIDIA CORPORATION. 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 as published by + * the Free Software Foundation, version 2 of the License. + * + * 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., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +#include <linux/kthread.h> +#include <linux/ktime.h> +#include <linux/miscdevice.h> +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/spinlock.h> +#include <linux/throughput_ioctl.h> +#include <linux/nvhost.h> +#include <mach/dc.h> + +#define DEFAULT_SYNC_RATE 60000 /* 60 Hz */ + +static unsigned short target_frame_time; +static unsigned short last_frame_time; +static ktime_t last_flip; +static unsigned int multiple_app_disable; +static spinlock_t lock; + +static struct work_struct work; +static int throughput_hint; + +static void set_throughput_hint(struct work_struct *work) +{ + /* notify throughput hint clients here */ + nvhost_scale3d_set_throughput_hint(throughput_hint); +} + +static int throughput_flip_callback(void) +{ + long timediff; + ktime_t now; + + /* only register flips when a single app is active */ + if (multiple_app_disable) + return NOTIFY_DONE; + + now = ktime_get(); + if (last_flip.tv64 != 0) { + timediff = (long) ktime_us_delta(now, last_flip); + if (timediff > (long) USHRT_MAX) + last_frame_time = USHRT_MAX; + else + last_frame_time = (unsigned short) timediff; + + if (last_frame_time == 0) { + pr_warn("%s: flips %lld nsec apart\n", + __func__, now.tv64 - last_flip.tv64); + return NOTIFY_DONE; + } + + throughput_hint = + ((int) target_frame_time * 1000) / last_frame_time; + + if (!work_pending(&work)) + schedule_work(&work); + } + last_flip = now; + + return NOTIFY_OK; +} + +static int sync_rate; +static int throughput_active_app_count; + +static void reset_target_frame_time(void) +{ + if (sync_rate == 0) { + sync_rate = tegra_dc_get_panel_sync_rate(); + + if (sync_rate == 0) + sync_rate = DEFAULT_SYNC_RATE; + } + + target_frame_time = (unsigned short) (1000000000 / sync_rate); + + pr_debug("%s: panel sync rate %d, target frame time %u\n", + __func__, sync_rate, target_frame_time); +} + +static int callback_initialized; + +static int throughput_open(struct inode *inode, struct file *file) +{ + spin_lock(&lock); + + if (!callback_initialized) { + callback_initialized = 1; + tegra_dc_set_flip_callback(throughput_flip_callback); + } + + throughput_active_app_count++; + if (throughput_active_app_count > 1) + multiple_app_disable = 1; + + spin_unlock(&lock); + + + pr_debug("throughput_open node %p file %p\n", inode, file); + + return 0; +} + +static int throughput_release(struct inode *inode, struct file *file) +{ + spin_lock(&lock); + + throughput_active_app_count--; + if (throughput_active_app_count == 0) { + reset_target_frame_time(); + multiple_app_disable = 0; + callback_initialized = 0; + tegra_dc_unset_flip_callback(); + } + + spin_unlock(&lock); + + pr_debug("throughput_release node %p file %p\n", inode, file); + + return 0; +} + +static int throughput_set_target_fps(unsigned long arg) +{ + int disable; + + pr_debug("%s: target fps %lu requested\n", __func__, arg); + + disable = multiple_app_disable; + + if (disable) { + pr_debug("%s: %d active apps, disabling fps usage\n", + __func__, throughput_active_app_count); + return 0; + } + + if (arg == 0) + reset_target_frame_time(); + else { + unsigned long frame_time = (1000000 / arg); + + if (frame_time > USHRT_MAX) + frame_time = USHRT_MAX; + + target_frame_time = (unsigned short) frame_time; + } + + return 0; +} + +static long +throughput_ioctl(struct file *file, + unsigned int cmd, + unsigned long arg) +{ + int err = 0; + + if ((_IOC_TYPE(cmd) != TEGRA_THROUGHPUT_MAGIC) || + (_IOC_NR(cmd) == 0) || + (_IOC_NR(cmd) > TEGRA_THROUGHPUT_IOCTL_MAXNR)) + return -EFAULT; + + switch (cmd) { + case TEGRA_THROUGHPUT_IOCTL_TARGET_FPS: + pr_debug("%s: TEGRA_THROUGHPUT_IOCTL_TARGET_FPS %lu\n", + __func__, arg); + err = throughput_set_target_fps(arg); + break; + + default: + err = -ENOTTY; + } + + return err; +} + +static const struct file_operations throughput_user_fops = { + .owner = THIS_MODULE, + .open = throughput_open, + .release = throughput_release, + .unlocked_ioctl = throughput_ioctl, +}; + +#define TEGRA_THROUGHPUT_MINOR 1 + +static struct miscdevice throughput_miscdev = { + .minor = TEGRA_THROUGHPUT_MINOR, + .name = "tegra-throughput", + .fops = &throughput_user_fops, + .mode = 0666, +}; + +int __init throughput_init_miscdev(void) +{ + int ret; + + pr_debug("%s: initializing\n", __func__); + + spin_lock_init(&lock); + INIT_WORK(&work, set_throughput_hint); + + ret = misc_register(&throughput_miscdev); + if (ret) { + pr_err("can\'t reigster throughput miscdev" + " (minor %d err %d)\n", TEGRA_THROUGHPUT_MINOR, ret); + return ret; + } + + return 0; +} + +module_init(throughput_init_miscdev); + +void __exit throughput_exit_miscdev(void) +{ + pr_debug("%s: exiting\n", __func__); + + cancel_work_sync(&work); + + misc_deregister(&throughput_miscdev); +} + +module_exit(throughput_exit_miscdev); + |