On Wednesday 25 October 2006 15:07, Pavel Machek wrote: > Hi! > > > > > a generic ACPI driver that exports the _BCL and _BCM method > > > > implementations via that same interface, so that systems providing > > > > that will "just work". drivers/acpi/video.c currently exports this > > > > via /proc/acpi/video/$DEVICE/brightness, which isn't the same as > > > > /sys/class/backlight. :-( > > > > > > Yes, I'm working on acpi video driver transition , and have posted a > > > patch to user backlight for acpi video driver. > > > http://marc.theaimsgroup.com/?l=linux-acpi&m=115574087203605&w=2 > > > > Just updated the backlight and output sysfs support for ACPI Video driver > > on bugzilla. If you are interested this, please take a look at > > http://bugzilla.kernel.org/show_bug.cgi?id=5749#c18 > > > > [patch 1/3] vidoe sysfs support: Add dev argument for baclight sys dev > > Two typos in one line :-). > > > [patch 2/3] Add display output class support > > I guess this needs Documentation/ so we can tell if user<->kernel > interface is sane.. > > > [patch 3/3] backlight and output sysfs support for acpi video driver > > Some whitespace is not okay there... > Pavel updated version. [patch 1/4] video sysfs support: Add dev argument for backlight sys dev drivers/video/backlight/backlight.c | 3 ++- include/linux/backlight.h | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-) [patch 2/4] Add display output class support drivers/video/output.c | 110 +++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/output.h | 23 ++++++++++ 2 files changed, 133 insertions(+) [patch 3/4] backlight and output sysfs support for acpi video driver acpi/Kconfig | 2 acpi/video.c | 257 +++++++++++++++++++++++++++++++++++++++++++++++++++++---- video/Kconfig | 8 + video/Makefile | 1 4 files changed, 252 insertions(+), 16 deletions(-) [patch 4/4] Add output class document video-output.txt | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) Thanks, Luming
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c index 27597c5..1a18cdb 100644 --- a/drivers/video/backlight/backlight.c +++ b/drivers/video/backlight/backlight.c @@ -190,7 +190,7 @@ static int fb_notifier_callback(struct n * Creates and registers new backlight class_device. Returns either an * ERR_PTR() or a pointer to the newly allocated device. */ -struct backlight_device *backlight_device_register(const char *name, void *devdata, +struct backlight_device *backlight_device_register(const char *name,struct device *dev, void *devdata, struct backlight_properties *bp) { int i, rc; @@ -206,6 +206,7 @@ struct backlight_device *backlight_devic new_bd->props = bp; memset(&new_bd->class_dev, 0, sizeof(new_bd->class_dev)); new_bd->class_dev.class = &backlight_class; + new_bd->class_dev.dev = dev; strlcpy(new_bd->class_dev.class_id, name, KOBJ_NAME_LEN); class_set_devdata(&new_bd->class_dev, devdata); diff --git a/include/linux/backlight.h b/include/linux/backlight.h index 75e91f5..de8e056 100644 --- a/include/linux/backlight.h +++ b/include/linux/backlight.h @@ -54,7 +54,7 @@ struct backlight_device { }; extern struct backlight_device *backlight_device_register(const char *name, - void *devdata, struct backlight_properties *bp); + struct device *dev, void *devdata, struct backlight_properties *bp); extern void backlight_device_unregister(struct backlight_device *bd); #define to_backlight_device(obj) container_of(obj, struct backlight_device, class_dev)
diff --git a/drivers/video/output.c b/drivers/video/output.c new file mode 100644 index 0000000..bcb2c53 --- /dev/null +++ b/drivers/video/output.c @@ -0,0 +1,110 @@ +/* + * Video output switch support + */ + +#include <linux/module.h> +#include <linux/output.h> +#include <linux/err.h> +#include <linux/ctype.h> + + +MODULE_DESCRIPTION("Output Lowlevel Control Abstraction"); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Luming Yu <luming.yu@xxxxxxxxx>"); + +static ssize_t video_output_show_state (struct class_device *dev, char *buf) +{ + ssize_t ret_size = 0; + struct output_device *od = to_output_device(dev); + + if(od->props) + ret_size = sprintf(buf, "%.8x\n", od->props->get_status(od)); + + return ret_size; +} + +static ssize_t video_output_store_state (struct class_device *dev, const char *buf, size_t count) +{ + char *endp; + struct output_device *od = to_output_device(dev); + int request_state = simple_strtoul(buf, &endp, 0); + size_t size = endp -buf; + + if (*endp && isspace(*endp)) + size++; + if (size != count) + return -EINVAL; + + if(od->props){ + od->request_state = request_state; + od->props->set_state(od); + } + return count; +} + +static void video_output_class_release(struct class_device *dev) +{ + struct output_device *od = to_output_device(dev); + kfree(od); +} + +static struct class_device_attribute video_output_attributes[] = { + __ATTR(state, 0644, video_output_show_state, video_output_store_state), + __ATTR_NULL, +}; + +static struct class video_output_class = { + .name = "video_output", + .release = video_output_class_release, + .class_dev_attrs = video_output_attributes, +}; + + +struct output_device *video_output_register(const char *name,struct device *dev, + void *devdata, struct output_properties *op) +{ + struct output_device *new_dev; + int ret_code = 0; + + new_dev = (struct output_device *) kzalloc( sizeof(struct output_device), GFP_KERNEL); + if (!new_dev) { + ret_code = -ENOMEM; + goto error_return; + } + new_dev->props = op; + new_dev->class_dev.class = &video_output_class; + new_dev->class_dev.dev = dev; + strlcpy(new_dev->class_dev.class_id, name, KOBJ_NAME_LEN); + class_set_devdata(&new_dev->class_dev, devdata); + ret_code = class_device_register(&new_dev->class_dev); + if (ret_code){ + kfree (new_dev); + goto error_return; + } + return new_dev; + +error_return: + return ERR_PTR(ret_code); +} +EXPORT_SYMBOL(video_output_register); + +void video_output_unregister(struct output_device *dev) +{ + if (!dev) + return; + class_device_unregister(&dev->class_dev); +} +EXPORT_SYMBOL(video_output_unregister); + +static void __exit video_output_class_exit(void) +{ + class_unregister(&video_output_class); +} + +static int __init video_output_class_init(void) +{ + return class_register(&video_output_class); +} + +postcore_initcall(video_output_class_init); +module_exit(video_output_class_exit); diff --git a/include/linux/output.h b/include/linux/output.h new file mode 100644 index 0000000..f4eb12c --- /dev/null +++ b/include/linux/output.h @@ -0,0 +1,23 @@ +#ifndef _LINUX_OUTPUT_H +#define _LINUX_OUTPUT_H + +#include <linux/device.h> + +struct output_device; + +struct output_properties { + int (*set_state)(struct output_device *); + int (*get_status)(struct output_device *); +}; + +struct output_device { + int request_state; + struct output_properties *props; + struct class_device class_dev; +}; + +#define to_output_device(obj) container_of(obj, struct output_device, class_dev) + +struct output_device *video_output_register(const char *, struct device *dev, void *, struct output_properties *); +void video_output_unregister(struct output_device *); +#endif
diff --git a/Documentation/video-output.txt b/Documentation/video-output.txt new file mode 100644 index 0000000..43cc0e2 --- /dev/null +++ b/Documentation/video-output.txt @@ -0,0 +1,27 @@ +The output sysfs class driver is to provide video output abstract layer that can be used to hook platform specific methods to enable/disable video output device through common sysfs interface. + +For example, on my IBM Thinkpad T42 laptop, acpi video driver registered its output devices and read/write method for state with output sysfs class. The user interface under sysfs is : + +linux:/sys/class/video_output # tree . +. +|-- CRT0 +| |-- device -> ../../../devices/pci0000:00/0000:00:01.0 +| |-- state +| |-- subsystem -> ../../../class/video_output +| `-- uevent +|-- DVI0 +| |-- device -> ../../../devices/pci0000:00/0000:00:01.0 +| |-- state +| |-- subsystem -> ../../../class/video_output +| `-- uevent +|-- LCD0 +| |-- device -> ../../../devices/pci0000:00/0000:00:01.0 +| |-- state +| |-- subsystem -> ../../../class/video_output +| `-- uevent +`-- TV0 + |-- device -> ../../../devices/pci0000:00/0000:00:01.0 + |-- state + |-- subsystem -> ../../../class/video_output + `-- uevent +
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index 0f9d4be..a7671f7 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -106,7 +106,7 @@ config ACPI_BUTTON config ACPI_VIDEO tristate "Video" - depends on X86 + depends on X86 && (BACKLIGHT_CLASS_DEVICE && VIDEO_OUTPUT_CONTROL) help This driver implement the ACPI Extensions For Display Adapters for integrated graphics devices on motherboard, as specified in diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c index 56666a9..0fcc68c 100644 --- a/drivers/acpi/video.c +++ b/drivers/acpi/video.c @@ -30,6 +30,9 @@ #include <linux/types.h> #include <linux/list.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> +#include <linux/pci.h> +#include <linux/backlight.h> +#include <linux/output.h> #include <asm/uaccess.h> @@ -141,11 +144,11 @@ struct acpi_video_device_cap { u8 _ADR:1; /*Return the unique ID */ u8 _BCL:1; /*Query list of brightness control levels supported */ u8 _BCM:1; /*Set the brightness level */ + u8 _BQC:1; /*Get current brightness level */ u8 _DDC:1; /*Return the EDID for this device */ u8 _DCS:1; /*Return status of output device */ u8 _DGS:1; /*Query graphics state */ u8 _DSS:1; /*Device state set */ - u8 _reserved:1; }; struct acpi_video_device_brightness { @@ -162,6 +165,7 @@ struct acpi_video_device { struct acpi_video_bus *video; struct acpi_device *dev; struct acpi_video_device_brightness *brightness; + struct output_device *output_dev; }; /* bus */ @@ -260,6 +264,56 @@ static int acpi_video_get_next_level(str u32 level_current, u32 event); static void acpi_video_switch_brightness(struct acpi_video_device *device, int event); +static int acpi_video_device_lcd_set_level(struct acpi_video_device *, int); +static int acpi_video_device_lcd_get_level_current(struct acpi_video_device *,unsigned long *); +/*backlight device sysfs support*/ +static int acpi_video_get_brightness(struct backlight_device *bd); +static int acpi_video_set_brightness(struct backlight_device *bd); +static int acpi_video_output_get(struct output_device *); +static int acpi_video_output_set(struct output_device *); +static int acpi_video_device_get_state(struct acpi_video_device *, unsigned long *); +static int acpi_video_device_set_state(struct acpi_video_device *, int); + +static struct backlight_device *acpi_video_backlight; +static struct acpi_video_device *backlight_acpi_device; +static struct backlight_properties acpi_video_data = { + .owner = THIS_MODULE, + .max_brightness = 0, + .get_brightness = acpi_video_get_brightness, + .update_status = acpi_video_set_brightness, +}; +static struct output_properties acpi_output_properties = { + .set_state = acpi_video_output_set, + .get_status = acpi_video_output_get, +}; +static int acpi_video_get_brightness(struct backlight_device *bd) +{ + unsigned long cur_level; + acpi_video_device_lcd_get_level_current(backlight_acpi_device, &cur_level); + return (int) cur_level; +} + +static int acpi_video_set_brightness(struct backlight_device *bd) +{ + int request_level = bd->props->brightness; + acpi_video_device_lcd_set_level(backlight_acpi_device, request_level); + return 0; +} + +static int acpi_video_output_get(struct output_device *od) +{ + unsigned long state; + struct acpi_video_device *vd = (struct acpi_video_device *)class_get_devdata(&od->class_dev); + acpi_video_device_get_state(vd, &state); + return (int)state; +} + +static int acpi_video_output_set(struct output_device *od) +{ + unsigned long state = od->request_state; + struct acpi_video_device *vd = (struct acpi_video_device *)class_get_devdata(&od->class_dev); + return acpi_video_device_set_state(vd, state); +} /* -------------------------------------------------------------------------- Video Management @@ -345,7 +399,7 @@ acpi_video_device_lcd_set_level(struct a arg0.integer.value = level; status = acpi_evaluate_object(device->dev->handle, "_BCM", &args, NULL); - printk(KERN_DEBUG "set_level status: %x\n", status); + printk(KERN_DEBUG PREFIX "set_level status: %x\n", status); return status; } @@ -482,6 +536,134 @@ acpi_video_bus_DOS(struct acpi_video_bus return status; } + +/* + * copy & paste some code for acpi_pci_data, acpi_pci_data_handler,acpi_pci_data + * from pci_bind.c + * To-do: write a new API: acpi_pci_get. + */ + +struct acpi_pci_data { + struct acpi_pci_id id; + struct pci_bus *bus; + struct pci_dev *dev; +}; + +static void acpi_pci_data_handler(acpi_handle handle, u32 function, + void *context) +{ + + /* TBD: Anything we need to do here? */ + + return; +} + +static struct acpi_pci_data * acpi_pci_get (struct acpi_device *device) +{ + int result = 0; + acpi_status status = AE_OK; + struct acpi_pci_data *data = NULL; + struct acpi_pci_data *pdata = NULL; + char *pathname = NULL; + struct acpi_buffer buffer = { 0, NULL }; + acpi_handle handle = NULL; + struct pci_dev *dev; + struct pci_bus *bus; + + + if (!device || !device->parent) + return NULL; + + pathname = kmalloc(ACPI_PATHNAME_MAX, GFP_KERNEL); + if (!pathname) + return -ENOMEM; + memset(pathname, 0, ACPI_PATHNAME_MAX); + buffer.length = ACPI_PATHNAME_MAX; + buffer.pointer = pathname; + + data = kmalloc(sizeof(struct acpi_pci_data), GFP_KERNEL); + if (!data) { + kfree(pathname); + return NULL; + } + memset(data, 0, sizeof(struct acpi_pci_data)); + + acpi_get_name(device->handle, ACPI_FULL_PATHNAME, &buffer); + printk(KERN_INFO PREFIX "finding PCI device [%s]...\n", pathname); + + /* + * Segment & Bus + * ------------- + * These are obtained via the parent device's ACPI-PCI context. + */ +go_up: + status = acpi_get_data(device->parent->handle, acpi_pci_data_handler, + (void **)&pdata); + if (ACPI_FAILURE(status) || !pdata || !pdata->bus) { + struct acpi_device *tmp_dev; + + tmp_dev = device->parent; + if (tmp_dev->parent && (tmp_dev->parent->handle != ACPI_ROOT_OBJECT)) { + device = tmp_dev; + goto go_up; + } + + ACPI_EXCEPTION((AE_INFO, status, + "Invalid ACPI-PCI context for parent device %s", + acpi_device_bid(device->parent))); + return NULL; + } + data->id.segment = pdata->id.segment; + data->id.bus = pdata->bus->number; + + /* + * Device & Function + * ----------------- + * These are simply obtained from the device's _ADR method. Note + * that a value of zero is valid. + */ + data->id.device = device->pnp.bus_address >> 16; + data->id.function = device->pnp.bus_address & 0xFFFF; + + printk(KERN_INFO PREFIX "...to %02x:%02x:%02x.%02x\n", + data->id.segment, data->id.bus, data->id.device, + data->id.function); + + /* + * TBD: Support slot devices (e.g. function=0xFFFF). + */ + + /* + * Locate PCI Device + * ----------------- + * Locate matching device in PCI namespace. If it doesn't exist + * this typically means that the device isn't currently inserted + * (e.g. docking station, port replicator, etc.). + * We cannot simply search the global pci device list, since + * PCI devices are added to the global pci list when the root + * bridge start ops are run, which may not have happened yet. + */ + bus = pci_find_bus(data->id.segment, data->id.bus); + if (bus) { + list_for_each_entry(dev, &bus->devices, bus_list) { + if (dev->devfn == PCI_DEVFN(data->id.device, + data->id.function)) { + data->dev = dev; + break; + } + } + } + printk(KERN_INFO PREFIX "data->dev =%p", &data->dev); + printk(KERN_INFO PREFIX "data->dev->dev =%p\n", &data->dev->dev); + if (!data->dev) { + printk(KERN_ERR PREFIX "Device %02x:%02x:%02x.%02x not present in PCI namespace\n", + data->id.segment, data->id.bus, + data->id.device, data->id.function); + return NULL; + } + return data; +} + /* * Arg: * device : video output device (LCD, CRT, ..) @@ -498,12 +680,18 @@ static void acpi_video_device_find_cap(s acpi_integer status; acpi_handle h_dummy1; int i; + u32 max_level = 0; union acpi_object *obj = NULL; struct acpi_video_device_brightness *br = NULL; + struct acpi_pci_data *data; + data = acpi_pci_get (device->video->device); + if (!data || !(data->dev)) { + printk(KERN_ERR PREFIX "acpi_video_device:no valid data from acpi_pci_get\n"); + return ; + } memset(&device->cap, 0, 4); - if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_ADR", &h_dummy1))) { device->cap._ADR = 1; } @@ -513,6 +701,9 @@ static void acpi_video_device_find_cap(s if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_BCM", &h_dummy1))) { device->cap._BCM = 1; } + if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_BQC", &h_dummy1))) { + device->cap._BQC = 1; + } if (ACPI_SUCCESS(acpi_get_handle(device->dev->handle, "_DDC", &h_dummy1))) { device->cap._DDC = 1; } @@ -526,6 +717,7 @@ static void acpi_video_device_find_cap(s device->cap._DSS = 1; } + status = acpi_video_device_lcd_query_levels(device, &obj); if (obj && obj->type == ACPI_TYPE_PACKAGE && obj->package.count >= 2) { @@ -534,7 +726,7 @@ static void acpi_video_device_find_cap(s br = kmalloc(sizeof(*br), GFP_KERNEL); if (!br) { - printk(KERN_ERR "can't allocate memory\n"); + printk(KERN_ERR PREFIX "can't allocate memory\n"); } else { memset(br, 0, sizeof(*br)); br->levels = kmalloc(obj->package.count * @@ -550,6 +742,8 @@ static void acpi_video_device_find_cap(s continue; } br->levels[count] = (u32) o->integer.value; + if (br->levels[count] > max_level) + max_level = br->levels[count]; count++; } out: @@ -568,6 +762,26 @@ static void acpi_video_device_find_cap(s kfree(obj); + if (device->cap._BCL && device->cap._BCM && device->cap._BQC){ + unsigned long tmp; + acpi_video_data.max_brightness = max_level; + acpi_video_device_lcd_get_level_current(device, &tmp); + acpi_video_data.brightness = tmp; + acpi_video_backlight = backlight_device_register("acpi-video", + &(data->dev->dev), NULL, &acpi_video_data); + backlight_acpi_device = device; + } + + if (device->cap._DCS && device->cap._DSS){ + char name[16]; + memset(name, 0, 16); + strcat(name, acpi_device_bid(device->dev->parent)); + strcat(name, "_"); + strcpy(name, acpi_device_bid(device->dev)); + device->output_dev = video_output_register(name, + &(data->dev->dev), + device, &acpi_output_properties); + } return; } @@ -1011,7 +1225,6 @@ static int acpi_video_bus_POST_info_seq_ printk(KERN_WARNING PREFIX "This indicate a BIOS bug. Please contact the manufacturer.\n"); } - printk("%lx\n", options); seq_printf(seq, "can POST: <intgrated video>"); if (options & 2) seq_printf(seq, " <PCI video>"); @@ -1148,11 +1361,15 @@ static int acpi_video_bus_add_fs(struct { struct proc_dir_entry *entry = NULL; struct acpi_video_bus *video; + char proc_dir_name[32]; - + memset(proc_dir_name, 0, 32); video = (struct acpi_video_bus *)acpi_driver_data(device); if (!acpi_device_dir(device)) { + strcpy(proc_dir_name, acpi_device_bid(device)); + strcat(proc_dir_name, "_"); + strcat(proc_dir_name, acpi_device_bid(device->parent)); acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device), acpi_video_dir); if (!acpi_device_dir(device)) @@ -1224,17 +1441,21 @@ static int acpi_video_bus_add_fs(struct static int acpi_video_bus_remove_fs(struct acpi_device *device) { struct acpi_video_bus *video; + char proc_dir_name[32]; - + memset(proc_dir_name, 0, 32); video = (struct acpi_video_bus *)acpi_driver_data(device); - if (acpi_device_dir(device)) { remove_proc_entry("info", acpi_device_dir(device)); remove_proc_entry("ROM", acpi_device_dir(device)); remove_proc_entry("POST_info", acpi_device_dir(device)); remove_proc_entry("POST", acpi_device_dir(device)); remove_proc_entry("DOS", acpi_device_dir(device)); - remove_proc_entry(acpi_device_bid(device), acpi_video_dir); + + strcpy(proc_dir_name, acpi_device_bid(device)); + strcat(proc_dir_name, "_"); + strcat(proc_dir_name, acpi_device_bid(device->parent)); + remove_proc_entry(proc_dir_name, acpi_video_dir); acpi_device_dir(device) = NULL; } @@ -1268,7 +1489,6 @@ acpi_video_bus_get_one_device(struct acp return -ENOMEM; memset(data, 0, sizeof(struct acpi_video_device)); - strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME); strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS); acpi_driver_data(device) = data; @@ -1568,6 +1788,10 @@ static int acpi_video_bus_put_one_device status = acpi_remove_notify_handler(device->dev->handle, ACPI_DEVICE_NOTIFY, acpi_video_device_notify); + if (device == backlight_acpi_device) + backlight_device_unregister(acpi_video_backlight); + + video_output_unregister(device->output_dev); return 0; } @@ -1615,7 +1839,7 @@ static void acpi_video_bus_notify(acpi_h struct acpi_video_bus *video = (struct acpi_video_bus *)data; struct acpi_device *device = NULL; - printk("video bus notify\n"); + printk(KERN_INFO PREFIX "video bus notify\n"); if (!video) return; @@ -1658,8 +1882,6 @@ static void acpi_video_device_notify(acp (struct acpi_video_device *)data; struct acpi_device *device = NULL; - - printk("video device notify\n"); if (!video_device) return; @@ -1691,8 +1913,9 @@ static int acpi_video_bus_add(struct acp int result = 0; acpi_status status = 0; struct acpi_video_bus *video = NULL; + char proc_dir_name[32]; - + memset(proc_dir_name, 0, 32); if (!device) return -EINVAL; @@ -1735,8 +1958,12 @@ static int acpi_video_bus_add(struct acp goto end; } + strcpy(proc_dir_name, acpi_device_bid(device)); + strcat(proc_dir_name, "_"); + strcat(proc_dir_name, acpi_device_bid(device->parent)); + printk(KERN_INFO PREFIX "%s [%s] (multi-head: %s rom: %s post: %s)\n", - ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device), + ACPI_VIDEO_DEVICE_NAME, proc_dir_name, video->flags.multihead ? "yes" : "no", video->flags.rom ? "yes" : "no", video->flags.post ? "yes" : "no"); diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig index 7a43020..3b51742 100644 --- a/drivers/video/Kconfig +++ b/drivers/video/Kconfig @@ -1644,5 +1644,13 @@ if SYSFS source "drivers/video/backlight/Kconfig" endif + +config VIDEO_OUTPUT_CONTROL + tristate "video output device switch control" + depends on SYSFS + ---help--- + sysfs support for video output device switching. + + endmenu diff --git a/drivers/video/Makefile b/drivers/video/Makefile index a6980e9..0f82eed 100644 --- a/drivers/video/Makefile +++ b/drivers/video/Makefile @@ -108,3 +108,4 @@ obj-$(CONFIG_FB_OF) += off # the test framebuffer is last obj-$(CONFIG_FB_VIRTUAL) += vfb.o +obj-$(CONFIG_VIDEO_OUTPUT_CONTROL) += output.o