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1// SPDX-License-Identifier: GPL-2.0+2// Keyboard backlight LED driver for ChromeOS3//4// Copyright (C) 2012 Google, Inc.5 6#include <linux/acpi.h>7#include <linux/delay.h>8#include <linux/err.h>9#include <linux/init.h>10#include <linux/kernel.h>11#include <linux/leds.h>12#include <linux/mfd/core.h>13#include <linux/mod_devicetable.h>14#include <linux/module.h>15#include <linux/of.h>16#include <linux/platform_data/cros_ec_commands.h>17#include <linux/platform_data/cros_ec_proto.h>18#include <linux/platform_device.h>19#include <linux/property.h>20#include <linux/slab.h>21 22struct keyboard_led {23 struct led_classdev cdev;24 struct cros_ec_device *ec;25};26 27/**28 * struct keyboard_led_drvdata - keyboard LED driver data.29 * @init: Init function.30 * @brightness_get: Get LED brightness level.31 * @brightness_set: Set LED brightness level. Must not sleep.32 * @brightness_set_blocking: Set LED brightness level. It can block the33 * caller for the time required for accessing a34 * LED device register35 * @max_brightness: Maximum brightness.36 *37 * See struct led_classdev in include/linux/leds.h for more details.38 */39struct keyboard_led_drvdata {40 int (*init)(struct platform_device *pdev);41 42 enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);43 44 void (*brightness_set)(struct led_classdev *led_cdev,45 enum led_brightness brightness);46 int (*brightness_set_blocking)(struct led_classdev *led_cdev,47 enum led_brightness brightness);48 49 enum led_brightness max_brightness;50};51 52#define KEYBOARD_BACKLIGHT_MAX 10053 54#ifdef CONFIG_ACPI55 56/* Keyboard LED ACPI Device must be defined in firmware */57#define ACPI_KEYBOARD_BACKLIGHT_DEVICE "\\_SB.KBLT"58#define ACPI_KEYBOARD_BACKLIGHT_READ ACPI_KEYBOARD_BACKLIGHT_DEVICE ".KBQC"59#define ACPI_KEYBOARD_BACKLIGHT_WRITE ACPI_KEYBOARD_BACKLIGHT_DEVICE ".KBCM"60 61static void keyboard_led_set_brightness_acpi(struct led_classdev *cdev,62 enum led_brightness brightness)63{64 union acpi_object param;65 struct acpi_object_list input;66 acpi_status status;67 68 param.type = ACPI_TYPE_INTEGER;69 param.integer.value = brightness;70 input.count = 1;71 input.pointer = ¶m;72 73 status = acpi_evaluate_object(NULL, ACPI_KEYBOARD_BACKLIGHT_WRITE,74 &input, NULL);75 if (ACPI_FAILURE(status))76 dev_err(cdev->dev, "Error setting keyboard LED value: %d\n",77 status);78}79 80static enum led_brightness81keyboard_led_get_brightness_acpi(struct led_classdev *cdev)82{83 unsigned long long brightness;84 acpi_status status;85 86 status = acpi_evaluate_integer(NULL, ACPI_KEYBOARD_BACKLIGHT_READ,87 NULL, &brightness);88 if (ACPI_FAILURE(status)) {89 dev_err(cdev->dev, "Error getting keyboard LED value: %d\n",90 status);91 return -EIO;92 }93 94 return brightness;95}96 97static int keyboard_led_init_acpi(struct platform_device *pdev)98{99 acpi_handle handle;100 acpi_status status;101 102 /* Look for the keyboard LED ACPI Device */103 status = acpi_get_handle(ACPI_ROOT_OBJECT,104 ACPI_KEYBOARD_BACKLIGHT_DEVICE,105 &handle);106 if (ACPI_FAILURE(status)) {107 dev_err(&pdev->dev, "Unable to find ACPI device %s: %d\n",108 ACPI_KEYBOARD_BACKLIGHT_DEVICE, status);109 return -ENXIO;110 }111 112 return 0;113}114 115static const struct keyboard_led_drvdata keyboard_led_drvdata_acpi = {116 .init = keyboard_led_init_acpi,117 .brightness_set = keyboard_led_set_brightness_acpi,118 .brightness_get = keyboard_led_get_brightness_acpi,119 .max_brightness = KEYBOARD_BACKLIGHT_MAX,120};121 122#endif /* CONFIG_ACPI */123 124#if IS_ENABLED(CONFIG_CROS_EC)125 126static int127keyboard_led_set_brightness_ec_pwm(struct led_classdev *cdev,128 enum led_brightness brightness)129{130 struct {131 struct cros_ec_command msg;132 struct ec_params_pwm_set_keyboard_backlight params;133 } __packed buf;134 struct ec_params_pwm_set_keyboard_backlight *params = &buf.params;135 struct cros_ec_command *msg = &buf.msg;136 struct keyboard_led *keyboard_led = container_of(cdev, struct keyboard_led, cdev);137 138 memset(&buf, 0, sizeof(buf));139 140 msg->command = EC_CMD_PWM_SET_KEYBOARD_BACKLIGHT;141 msg->outsize = sizeof(*params);142 143 params->percent = brightness;144 145 return cros_ec_cmd_xfer_status(keyboard_led->ec, msg);146}147 148static enum led_brightness149keyboard_led_get_brightness_ec_pwm(struct led_classdev *cdev)150{151 struct {152 struct cros_ec_command msg;153 struct ec_response_pwm_get_keyboard_backlight resp;154 } __packed buf;155 struct ec_response_pwm_get_keyboard_backlight *resp = &buf.resp;156 struct cros_ec_command *msg = &buf.msg;157 struct keyboard_led *keyboard_led = container_of(cdev, struct keyboard_led, cdev);158 int ret;159 160 memset(&buf, 0, sizeof(buf));161 162 msg->command = EC_CMD_PWM_GET_KEYBOARD_BACKLIGHT;163 msg->insize = sizeof(*resp);164 165 ret = cros_ec_cmd_xfer_status(keyboard_led->ec, msg);166 if (ret < 0)167 return ret;168 169 return resp->percent;170}171 172static int keyboard_led_init_ec_pwm(struct platform_device *pdev)173{174 struct keyboard_led *keyboard_led = platform_get_drvdata(pdev);175 176 keyboard_led->ec = dev_get_drvdata(pdev->dev.parent);177 if (!keyboard_led->ec) {178 dev_err(&pdev->dev, "no parent EC device\n");179 return -EINVAL;180 }181 182 return 0;183}184 185static const __maybe_unused struct keyboard_led_drvdata keyboard_led_drvdata_ec_pwm = {186 .init = keyboard_led_init_ec_pwm,187 .brightness_set_blocking = keyboard_led_set_brightness_ec_pwm,188 .brightness_get = keyboard_led_get_brightness_ec_pwm,189 .max_brightness = KEYBOARD_BACKLIGHT_MAX,190};191 192#else /* IS_ENABLED(CONFIG_CROS_EC) */193 194static const __maybe_unused struct keyboard_led_drvdata keyboard_led_drvdata_ec_pwm = {};195 196#endif /* IS_ENABLED(CONFIG_CROS_EC) */197 198#if IS_ENABLED(CONFIG_MFD_CROS_EC_DEV)199static int keyboard_led_init_ec_pwm_mfd(struct platform_device *pdev)200{201 struct cros_ec_dev *ec_dev = dev_get_drvdata(pdev->dev.parent);202 struct cros_ec_device *cros_ec = ec_dev->ec_dev;203 struct keyboard_led *keyboard_led = platform_get_drvdata(pdev);204 205 keyboard_led->ec = cros_ec;206 207 return 0;208}209 210static const struct keyboard_led_drvdata keyboard_led_drvdata_ec_pwm_mfd = {211 .init = keyboard_led_init_ec_pwm_mfd,212 .brightness_set_blocking = keyboard_led_set_brightness_ec_pwm,213 .brightness_get = keyboard_led_get_brightness_ec_pwm,214 .max_brightness = KEYBOARD_BACKLIGHT_MAX,215};216 217#else /* IS_ENABLED(CONFIG_MFD_CROS_EC_DEV) */218 219static const struct keyboard_led_drvdata keyboard_led_drvdata_ec_pwm_mfd = {};220 221#endif /* IS_ENABLED(CONFIG_MFD_CROS_EC_DEV) */222 223static int keyboard_led_is_mfd_device(struct platform_device *pdev)224{225 return IS_ENABLED(CONFIG_MFD_CROS_EC_DEV) && mfd_get_cell(pdev);226}227 228static int keyboard_led_probe(struct platform_device *pdev)229{230 const struct keyboard_led_drvdata *drvdata;231 struct keyboard_led *keyboard_led;232 int error;233 234 if (keyboard_led_is_mfd_device(pdev))235 drvdata = &keyboard_led_drvdata_ec_pwm_mfd;236 else237 drvdata = device_get_match_data(&pdev->dev);238 if (!drvdata)239 return -EINVAL;240 241 keyboard_led = devm_kzalloc(&pdev->dev, sizeof(*keyboard_led), GFP_KERNEL);242 if (!keyboard_led)243 return -ENOMEM;244 platform_set_drvdata(pdev, keyboard_led);245 246 if (drvdata->init) {247 error = drvdata->init(pdev);248 if (error)249 return error;250 }251 252 keyboard_led->cdev.name = "chromeos::kbd_backlight";253 keyboard_led->cdev.flags |= LED_CORE_SUSPENDRESUME | LED_REJECT_NAME_CONFLICT;254 keyboard_led->cdev.max_brightness = drvdata->max_brightness;255 keyboard_led->cdev.brightness_set = drvdata->brightness_set;256 keyboard_led->cdev.brightness_set_blocking = drvdata->brightness_set_blocking;257 keyboard_led->cdev.brightness_get = drvdata->brightness_get;258 259 error = devm_led_classdev_register(&pdev->dev, &keyboard_led->cdev);260 if (error == -EEXIST) /* Already bound via other mechanism */261 return -ENODEV;262 if (error)263 return error;264 265 return 0;266}267 268#ifdef CONFIG_ACPI269static const struct acpi_device_id keyboard_led_acpi_match[] = {270 { "GOOG0002", (kernel_ulong_t)&keyboard_led_drvdata_acpi },271 { }272};273MODULE_DEVICE_TABLE(acpi, keyboard_led_acpi_match);274#endif275 276#ifdef CONFIG_OF277static const struct of_device_id keyboard_led_of_match[] = {278 {279 .compatible = "google,cros-kbd-led-backlight",280 .data = &keyboard_led_drvdata_ec_pwm,281 },282 {}283};284MODULE_DEVICE_TABLE(of, keyboard_led_of_match);285#endif286 287static const struct platform_device_id keyboard_led_id[] = {288 { "cros-keyboard-leds", 0 },289 {}290};291MODULE_DEVICE_TABLE(platform, keyboard_led_id);292 293static struct platform_driver keyboard_led_driver = {294 .driver = {295 .name = "cros-keyboard-leds",296 .acpi_match_table = ACPI_PTR(keyboard_led_acpi_match),297 .of_match_table = of_match_ptr(keyboard_led_of_match),298 },299 .probe = keyboard_led_probe,300 .id_table = keyboard_led_id,301};302module_platform_driver(keyboard_led_driver);303 304MODULE_AUTHOR("Simon Que <sque@chromium.org>");305MODULE_DESCRIPTION("ChromeOS Keyboard backlight LED Driver");306MODULE_LICENSE("GPL");307