1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * SGI Volume Button interface driver 4 * 5 * Copyright (C) 2008 Thomas Bogendoerfer <tsbogend@alpha.franken.de> 6 */ 7 #include <linux/input.h> 8 #include <linux/ioport.h> 9 #include <linux/module.h> 10 #include <linux/platform_device.h> 11 #include <linux/slab.h> 12 13 #ifdef CONFIG_SGI_IP22 14 #include <asm/sgi/ioc.h> 15 16 static inline u8 button_status(void) 17 { 18 u8 status; 19 20 status = readb(&sgioc->panel) ^ 0xa0; 21 return ((status & 0x80) >> 6) | ((status & 0x20) >> 5); 22 } 23 #endif 24 25 #ifdef CONFIG_SGI_IP32 26 #include <asm/ip32/mace.h> 27 28 static inline u8 button_status(void) 29 { 30 u64 status; 31 32 status = readq(&mace->perif.audio.control); 33 writeq(status & ~(3U << 23), &mace->perif.audio.control); 34 35 return (status >> 23) & 3; 36 } 37 #endif 38 39 #define BUTTONS_POLL_INTERVAL 30 /* msec */ 40 #define BUTTONS_COUNT_THRESHOLD 3 41 42 static const unsigned short sgi_map[] = { 43 KEY_VOLUMEDOWN, 44 KEY_VOLUMEUP 45 }; 46 47 struct buttons_dev { 48 unsigned short keymap[ARRAY_SIZE(sgi_map)]; 49 int count[ARRAY_SIZE(sgi_map)]; 50 }; 51 52 static void handle_buttons(struct input_dev *input) 53 { 54 struct buttons_dev *bdev = input_get_drvdata(input); 55 u8 status; 56 int i; 57 58 status = button_status(); 59 60 for (i = 0; i < ARRAY_SIZE(bdev->keymap); i++) { 61 if (status & (1U << i)) { 62 if (++bdev->count[i] == BUTTONS_COUNT_THRESHOLD) { 63 input_event(input, EV_MSC, MSC_SCAN, i); 64 input_report_key(input, bdev->keymap[i], 1); 65 input_sync(input); 66 } 67 } else { 68 if (bdev->count[i] >= BUTTONS_COUNT_THRESHOLD) { 69 input_event(input, EV_MSC, MSC_SCAN, i); 70 input_report_key(input, bdev->keymap[i], 0); 71 input_sync(input); 72 } 73 bdev->count[i] = 0; 74 } 75 } 76 } 77 78 static int sgi_buttons_probe(struct platform_device *pdev) 79 { 80 struct buttons_dev *bdev; 81 struct input_dev *input; 82 int error, i; 83 84 bdev = devm_kzalloc(&pdev->dev, sizeof(*bdev), GFP_KERNEL); 85 if (!bdev) 86 return -ENOMEM; 87 88 input = devm_input_allocate_device(&pdev->dev); 89 if (!input) 90 return -ENOMEM; 91 92 memcpy(bdev->keymap, sgi_map, sizeof(bdev->keymap)); 93 94 input_set_drvdata(input, bdev); 95 96 input->name = "SGI buttons"; 97 input->phys = "sgi/input0"; 98 input->id.bustype = BUS_HOST; 99 100 input->keycode = bdev->keymap; 101 input->keycodemax = ARRAY_SIZE(bdev->keymap); 102 input->keycodesize = sizeof(unsigned short); 103 104 input_set_capability(input, EV_MSC, MSC_SCAN); 105 __set_bit(EV_KEY, input->evbit); 106 for (i = 0; i < ARRAY_SIZE(sgi_map); i++) 107 __set_bit(bdev->keymap[i], input->keybit); 108 __clear_bit(KEY_RESERVED, input->keybit); 109 110 error = input_setup_polling(input, handle_buttons); 111 if (error) 112 return error; 113 114 input_set_poll_interval(input, BUTTONS_POLL_INTERVAL); 115 116 error = input_register_device(input); 117 if (error) 118 return error; 119 120 return 0; 121 } 122 123 static struct platform_driver sgi_buttons_driver = { 124 .probe = sgi_buttons_probe, 125 .driver = { 126 .name = "sgibtns", 127 }, 128 }; 129 module_platform_driver(sgi_buttons_driver); 130 131 MODULE_LICENSE("GPL"); 132