diff options
Diffstat (limited to 'drivers/hwtracing/stm/core.c')
| -rw-r--r-- | drivers/hwtracing/stm/core.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c index ff31108b066f..51f81d64ca37 100644 --- a/drivers/hwtracing/stm/core.c +++ b/drivers/hwtracing/stm/core.c @@ -15,6 +15,7 @@ * as defined in MIPI STPv2 specification. */ +#include <linux/pm_runtime.h> #include <linux/uaccess.h> #include <linux/kernel.h> #include <linux/module.h> @@ -482,14 +483,40 @@ static ssize_t stm_char_write(struct file *file, const char __user *buf, return -EFAULT; } + pm_runtime_get_sync(&stm->dev); + count = stm_write(stm->data, stmf->output.master, stmf->output.channel, kbuf, count); + pm_runtime_mark_last_busy(&stm->dev); + pm_runtime_put_autosuspend(&stm->dev); kfree(kbuf); return count; } +static void stm_mmap_open(struct vm_area_struct *vma) +{ + struct stm_file *stmf = vma->vm_file->private_data; + struct stm_device *stm = stmf->stm; + + pm_runtime_get(&stm->dev); +} + +static void stm_mmap_close(struct vm_area_struct *vma) +{ + struct stm_file *stmf = vma->vm_file->private_data; + struct stm_device *stm = stmf->stm; + + pm_runtime_mark_last_busy(&stm->dev); + pm_runtime_put_autosuspend(&stm->dev); +} + +static const struct vm_operations_struct stm_mmap_vmops = { + .open = stm_mmap_open, + .close = stm_mmap_close, +}; + static int stm_char_mmap(struct file *file, struct vm_area_struct *vma) { struct stm_file *stmf = file->private_data; @@ -514,8 +541,11 @@ static int stm_char_mmap(struct file *file, struct vm_area_struct *vma) if (!phys) return -EINVAL; + pm_runtime_get_sync(&stm->dev); + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP; + vma->vm_ops = &stm_mmap_vmops; vm_iomap_memory(vma, phys, size); return 0; @@ -701,6 +731,17 @@ int stm_register_device(struct device *parent, struct stm_data *stm_data, if (err) goto err_device; + /* + * Use delayed autosuspend to avoid bouncing back and forth + * on recurring character device writes, with the initial + * delay time of 2 seconds. + */ + pm_runtime_no_callbacks(&stm->dev); + pm_runtime_use_autosuspend(&stm->dev); + pm_runtime_set_autosuspend_delay(&stm->dev, 2000); + pm_runtime_set_suspended(&stm->dev); + pm_runtime_enable(&stm->dev); + return 0; err_device: @@ -724,6 +765,9 @@ void stm_unregister_device(struct stm_data *stm_data) struct stm_source_device *src, *iter; int i, ret; + pm_runtime_dont_use_autosuspend(&stm->dev); + pm_runtime_disable(&stm->dev); + mutex_lock(&stm->link_mutex); list_for_each_entry_safe(src, iter, &stm->link_list, link_entry) { ret = __stm_source_link_drop(src, stm); @@ -878,6 +922,8 @@ static int __stm_source_link_drop(struct stm_source_device *src, stm_output_free(link, &src->output); list_del_init(&src->link_entry); + pm_runtime_mark_last_busy(&link->dev); + pm_runtime_put_autosuspend(&link->dev); /* matches stm_find_device() from stm_source_link_store() */ stm_put_device(link); rcu_assign_pointer(src->link, NULL); @@ -971,8 +1017,11 @@ static ssize_t stm_source_link_store(struct device *dev, if (!link) return -EINVAL; + pm_runtime_get(&link->dev); + err = stm_source_link_add(src, link); if (err) { + pm_runtime_put_autosuspend(&link->dev); /* matches the stm_find_device() above */ stm_put_device(link); } @@ -1033,6 +1082,9 @@ int stm_source_register_device(struct device *parent, if (err) goto err; + pm_runtime_no_callbacks(&src->dev); + pm_runtime_forbid(&src->dev); + err = device_add(&src->dev); if (err) goto err; |