drivers/input/keyboard/goldfish_events.c

   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
  18 enum {
  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
  29 struct event_dev {
  30         struct input_dev *input;
  31         int irq;
  32         void __iomem *addr;
  33         char name[0];
  34 };
  35
  36 static 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
  50 static 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
  73 static 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
 102 static 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
 174 static const struct of_device_id goldfish_events_of_match[] = {
 175         { .compatible = "google,goldfish-events-keypad", },
 176         {},
 177 };
 178 MODULE_DEVICE_TABLE(of, goldfish_events_of_match);
 179
 180 #ifdef CONFIG_ACPI
 181 static const struct acpi_device_id goldfish_events_acpi_match[] = {
 182         { "GFSH0002", 0 },
 183         { },
 184 };
 185 MODULE_DEVICE_TABLE(acpi, goldfish_events_acpi_match);
 186 #endif
 187
 188 static 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
 197 module_platform_driver(events_driver);
 198
 199 MODULE_AUTHOR("Brian Swetland");
 200 MODULE_DESCRIPTION("Goldfish Event Device");
 201 MODULE_LICENSE("GPL");