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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 | // SPDX-License-Identifier: GPL-2.0-only /* * Copyright (c) 2020, NVIDIA CORPORATION. All rights reserved. */ #include <linux/acpi.h> #include <linux/backlight.h> #include <linux/mod_devicetable.h> #include <linux/module.h> #include <linux/platform_data/x86/nvidia-wmi-ec-backlight.h> #include <linux/types.h> #include <linux/wmi.h> #include <acpi/video.h> static bool force; module_param(force, bool, 0444); MODULE_PARM_DESC(force, "Force loading (disable acpi_backlight=xxx checks"); /** * wmi_brightness_notify() - helper function for calling WMI-wrapped ACPI method * @w: Pointer to the struct wmi_device identified by %WMI_BRIGHTNESS_GUID * @id: The WMI method ID to call (e.g. %WMI_BRIGHTNESS_METHOD_LEVEL or * %WMI_BRIGHTNESS_METHOD_SOURCE) * @mode: The operation to perform on the method (e.g. %WMI_BRIGHTNESS_MODE_SET * or %WMI_BRIGHTNESS_MODE_GET) * @val: Pointer to a value passed in by the caller when @mode is * %WMI_BRIGHTNESS_MODE_SET, or a value passed out to caller when @mode * is %WMI_BRIGHTNESS_MODE_GET or %WMI_BRIGHTNESS_MODE_GET_MAX_LEVEL. * * Returns 0 on success, or a negative error number on failure. */ static int wmi_brightness_notify(struct wmi_device *w, enum wmi_brightness_method id, enum wmi_brightness_mode mode, u32 *val) { struct wmi_brightness_args args = { .mode = mode, .val = 0, .ret = 0, }; struct acpi_buffer buf = { (acpi_size)sizeof(args), &args }; acpi_status status; if (id < WMI_BRIGHTNESS_METHOD_LEVEL || id >= WMI_BRIGHTNESS_METHOD_MAX || mode < WMI_BRIGHTNESS_MODE_GET || mode >= WMI_BRIGHTNESS_MODE_MAX) return -EINVAL; if (mode == WMI_BRIGHTNESS_MODE_SET) args.val = *val; status = wmidev_evaluate_method(w, 0, id, &buf, &buf); if (ACPI_FAILURE(status)) { dev_err(&w->dev, "EC backlight control failed: %s\n", acpi_format_exception(status)); return -EIO; } if (mode != WMI_BRIGHTNESS_MODE_SET) *val = args.ret; return 0; } static int nvidia_wmi_ec_backlight_update_status(struct backlight_device *bd) { struct wmi_device *wdev = bl_get_data(bd); return wmi_brightness_notify(wdev, WMI_BRIGHTNESS_METHOD_LEVEL, WMI_BRIGHTNESS_MODE_SET, &bd->props.brightness); } static int nvidia_wmi_ec_backlight_get_brightness(struct backlight_device *bd) { struct wmi_device *wdev = bl_get_data(bd); u32 level; int ret; ret = wmi_brightness_notify(wdev, WMI_BRIGHTNESS_METHOD_LEVEL, WMI_BRIGHTNESS_MODE_GET, &level); if (ret < 0) return ret; return level; } static const struct backlight_ops nvidia_wmi_ec_backlight_ops = { .update_status = nvidia_wmi_ec_backlight_update_status, .get_brightness = nvidia_wmi_ec_backlight_get_brightness, }; static int nvidia_wmi_ec_backlight_probe(struct wmi_device *wdev, const void *ctx) { struct backlight_properties props = {}; struct backlight_device *bdev; int ret; /* drivers/acpi/video_detect.c also checks that SOURCE == EC */ if (!force && acpi_video_get_backlight_type() != acpi_backlight_nvidia_wmi_ec) return -ENODEV; /* * Identify this backlight device as a firmware device so that it can * be prioritized over any exposed GPU-driven raw device(s). */ props.type = BACKLIGHT_FIRMWARE; ret = wmi_brightness_notify(wdev, WMI_BRIGHTNESS_METHOD_LEVEL, WMI_BRIGHTNESS_MODE_GET_MAX_LEVEL, &props.max_brightness); if (ret) return ret; ret = wmi_brightness_notify(wdev, WMI_BRIGHTNESS_METHOD_LEVEL, WMI_BRIGHTNESS_MODE_GET, &props.brightness); if (ret) return ret; bdev = devm_backlight_device_register(&wdev->dev, "nvidia_wmi_ec_backlight", &wdev->dev, wdev, &nvidia_wmi_ec_backlight_ops, &props); return PTR_ERR_OR_ZERO(bdev); } static const struct wmi_device_id nvidia_wmi_ec_backlight_id_table[] = { { .guid_string = WMI_BRIGHTNESS_GUID }, { } }; MODULE_DEVICE_TABLE(wmi, nvidia_wmi_ec_backlight_id_table); static struct wmi_driver nvidia_wmi_ec_backlight_driver = { .driver = { .name = "nvidia-wmi-ec-backlight", }, .probe = nvidia_wmi_ec_backlight_probe, .id_table = nvidia_wmi_ec_backlight_id_table, }; module_wmi_driver(nvidia_wmi_ec_backlight_driver); MODULE_AUTHOR("Daniel Dadap <ddadap@nvidia.com>"); MODULE_DESCRIPTION("NVIDIA WMI EC Backlight driver"); MODULE_LICENSE("GPL"); |