linux/drivers/input/keyboard/goldfish_events.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2007 Google, Inc.
   4 * Copyright (C) 2012 Intel, Inc.
   5 */
   6
   7#include <linux/module.h>
   8#include <linux/interrupt.h>
   9#include <linux/types.h>
  10#include <linux/input.h>
  11#include <linux/kernel.h>
  12#include <linux/platform_device.h>
  13#include <linux/slab.h>
  14#include <linux/irq.h>
  15#include <linux/io.h>
  16#include <linux/acpi.h>
  17
  18enum {
  19        REG_READ        = 0x00,
  20        REG_SET_PAGE    = 0x00,
  21        REG_LEN         = 0x04,
  22        REG_DATA        = 0x08,
  23
  24        PAGE_NAME       = 0x00000,
  25        PAGE_EVBITS     = 0x10000,
  26        PAGE_ABSDATA    = 0x20000 | EV_ABS,
  27};
  28
  29struct event_dev {
  30        struct input_dev *input;
  31        int irq;
  32        void __iomem *addr;
  33        char name[0];
  34};
  35
  36static irqreturn_t events_interrupt(int irq, void *dev_id)
  37{
  38        struct event_dev *edev = dev_id;
  39        unsigned int type, code, value;
  40
  41        type = __raw_readl(edev->addr + REG_READ);
  42        code = __raw_readl(edev->addr + REG_READ);
  43        value = __raw_readl(edev->addr + REG_READ);
  44
  45        input_event(edev->input, type, code, value);
  46        input_sync(edev->input);
  47        return IRQ_HANDLED;
  48}
  49
  50static void events_import_bits(struct event_dev *edev,
  51                        unsigned long bits[], unsigned int type, size_t count)
  52{
  53        void __iomem *addr = edev->addr;
  54        int i, j;
  55        size_t size;
  56        uint8_t val;
  57
  58        __raw_writel(PAGE_EVBITS | type, addr + REG_SET_PAGE);
  59
  60        size = __raw_readl(addr + REG_LEN) * 8;
  61        if (size < count)
  62                count = size;
  63
  64        addr += REG_DATA;
  65        for (i = 0; i < count; i += 8) {
  66                val = __raw_readb(addr++);
  67                for (j = 0; j < 8; j++)
  68                        if (val & 1 << j)
  69                                set_bit(i + j, bits);
  70        }
  71}
  72
  73static void events_import_abs_params(struct event_dev *edev)
  74{
  75        struct input_dev *input_dev = edev->input;
  76        void __iomem *addr = edev->addr;
  77        u32 val[4];
  78        int count;
  79        int i, j;
  80
  81        __raw_writel(PAGE_ABSDATA, addr + REG_SET_PAGE);
  82
  83        count = __raw_readl(addr + REG_LEN) / sizeof(val);
  84        if (count > ABS_MAX)
  85                count = ABS_MAX;
  86
  87        for (i = 0; i < count; i++) {
  88                if (!test_bit(i, input_dev->absbit))
  89                        continue;
  90
  91                for (j = 0; j < ARRAY_SIZE(val); j++) {
  92                        int offset = (i * ARRAY_SIZE(val) + j) * sizeof(u32);
  93
  94                        val[j] = __raw_readl(edev->addr + REG_DATA + offset);
  95                }
  96
  97                input_set_abs_params(input_dev, i,
  98                                     val[0], val[1], val[2], val[3]);
  99        }
 100}
 101
 102static int events_probe(struct platform_device *pdev)
 103{
 104        struct input_dev *input_dev;
 105        struct event_dev *edev;
 106        struct resource *res;
 107        unsigned int keymapnamelen;
 108        void __iomem *addr;
 109        int irq;
 110        int i;
 111        int error;
 112
 113        irq = platform_get_irq(pdev, 0);
 114        if (irq < 0)
 115                return -EINVAL;
 116
 117        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 118        if (!res)
 119                return -EINVAL;
 120
 121        addr = devm_ioremap(&pdev->dev, res->start, 4096);
 122        if (!addr)
 123                return -ENOMEM;
 124
 125        __raw_writel(PAGE_NAME, addr + REG_SET_PAGE);
 126        keymapnamelen = __raw_readl(addr + REG_LEN);
 127
 128        edev = devm_kzalloc(&pdev->dev,
 129                            sizeof(struct event_dev) + keymapnamelen + 1,
 130                            GFP_KERNEL);
 131        if (!edev)
 132                return -ENOMEM;
 133
 134        input_dev = devm_input_allocate_device(&pdev->dev);
 135        if (!input_dev)
 136                return -ENOMEM;
 137
 138        edev->input = input_dev;
 139        edev->addr = addr;
 140        edev->irq = irq;
 141
 142        for (i = 0; i < keymapnamelen; i++)
 143                edev->name[i] = __raw_readb(edev->addr + REG_DATA + i);
 144
 145        pr_debug("%s: keymap=%s\n", __func__, edev->name);
 146
 147        input_dev->name = edev->name;
 148        input_dev->id.bustype = BUS_HOST;
 149
 150        events_import_bits(edev, input_dev->evbit, EV_SYN, EV_MAX);
 151        events_import_bits(edev, input_dev->keybit, EV_KEY, KEY_MAX);
 152        events_import_bits(edev, input_dev->relbit, EV_REL, REL_MAX);
 153        events_import_bits(edev, input_dev->absbit, EV_ABS, ABS_MAX);
 154        events_import_bits(edev, input_dev->mscbit, EV_MSC, MSC_MAX);
 155        events_import_bits(edev, input_dev->ledbit, EV_LED, LED_MAX);
 156        events_import_bits(edev, input_dev->sndbit, EV_SND, SND_MAX);
 157        events_import_bits(edev, input_dev->ffbit, EV_FF, FF_MAX);
 158        events_import_bits(edev, input_dev->swbit, EV_SW, SW_MAX);
 159
 160        events_import_abs_params(edev);
 161
 162        error = devm_request_irq(&pdev->dev, edev->irq, events_interrupt, 0,
 163                                 "goldfish-events-keypad", edev);
 164        if (error)
 165                return error;
 166
 167        error = input_register_device(input_dev);
 168        if (error)
 169                return error;
 170
 171        return 0;
 172}
 173
 174static const struct of_device_id goldfish_events_of_match[] = {
 175        { .compatible = "google,goldfish-events-keypad", },
 176        {},
 177};
 178MODULE_DEVICE_TABLE(of, goldfish_events_of_match);
 179
 180#ifdef CONFIG_ACPI
 181static const struct acpi_device_id goldfish_events_acpi_match[] = {
 182        { "GFSH0002", 0 },
 183        { },
 184};
 185MODULE_DEVICE_TABLE(acpi, goldfish_events_acpi_match);
 186#endif
 187
 188static struct platform_driver events_driver = {
 189        .probe  = events_probe,
 190        .driver = {
 191                .name   = "goldfish_events",
 192                .of_match_table = goldfish_events_of_match,
 193                .acpi_match_table = ACPI_PTR(goldfish_events_acpi_match),
 194        },
 195};
 196
 197module_platform_driver(events_driver);
 198
 199MODULE_AUTHOR("Brian Swetland");
 200MODULE_DESCRIPTION("Goldfish Event Device");
 201MODULE_LICENSE("GPL");
 202