input/keyboard/goldfish_events.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright (C) 2007 Google, Inc.
0004  * Copyright (C) 2012 Intel, Inc.
0005  */
0006
0007 #include <linux/module.h>
0008 #include <linux/interrupt.h>
0009 #include <linux/types.h>
0010 #include <linux/input.h>
0011 #include <linux/kernel.h>
0012 #include <linux/platform_device.h>
0013 #include <linux/slab.h>
0014 #include <linux/irq.h>
0015 #include <linux/io.h>
0016 #include <linux/acpi.h>
0017
0018 enum {
0019     REG_READ        = 0x00,
0020     REG_SET_PAGE    = 0x00,
0021     REG_LEN         = 0x04,
0022     REG_DATA        = 0x08,
0023
0024     PAGE_NAME       = 0x00000,
0025     PAGE_EVBITS     = 0x10000,
0026     PAGE_ABSDATA    = 0x20000 | EV_ABS,
0027 };
0028
0029 struct event_dev {
0030     struct input_dev *input;
0031     int irq;
0032     void __iomem *addr;
0033     char name[];
0034 };
0035
0036 static irqreturn_t events_interrupt(int irq, void *dev_id)
0037 {
0038     struct event_dev *edev = dev_id;
0039     unsigned int type, code, value;
0040
0041     type = __raw_readl(edev->addr + REG_READ);
0042     code = __raw_readl(edev->addr + REG_READ);
0043     value = __raw_readl(edev->addr + REG_READ);
0044
0045     input_event(edev->input, type, code, value);
0046     input_sync(edev->input);
0047     return IRQ_HANDLED;
0048 }
0049
0050 static void events_import_bits(struct event_dev *edev,
0051             unsigned long bits[], unsigned int type, size_t count)
0052 {
0053     void __iomem *addr = edev->addr;
0054     int i, j;
0055     size_t size;
0056     uint8_t val;
0057
0058     __raw_writel(PAGE_EVBITS | type, addr + REG_SET_PAGE);
0059
0060     size = __raw_readl(addr + REG_LEN) * 8;
0061     if (size < count)
0062         count = size;
0063
0064     addr += REG_DATA;
0065     for (i = 0; i < count; i += 8) {
0066         val = __raw_readb(addr++);
0067         for (j = 0; j < 8; j++)
0068             if (val & 1 << j)
0069                 set_bit(i + j, bits);
0070     }
0071 }
0072
0073 static void events_import_abs_params(struct event_dev *edev)
0074 {
0075     struct input_dev *input_dev = edev->input;
0076     void __iomem *addr = edev->addr;
0077     u32 val[4];
0078     int count;
0079     int i, j;
0080
0081     __raw_writel(PAGE_ABSDATA, addr + REG_SET_PAGE);
0082
0083     count = __raw_readl(addr + REG_LEN) / sizeof(val);
0084     if (count > ABS_MAX)
0085         count = ABS_MAX;
0086
0087     for (i = 0; i < count; i++) {
0088         if (!test_bit(i, input_dev->absbit))
0089             continue;
0090
0091         for (j = 0; j < ARRAY_SIZE(val); j++) {
0092             int offset = (i * ARRAY_SIZE(val) + j) * sizeof(u32);
0093
0094             val[j] = __raw_readl(edev->addr + REG_DATA + offset);
0095         }
0096
0097         input_set_abs_params(input_dev, i,
0098                      val[0], val[1], val[2], val[3]);
0099     }
0100 }
0101
0102 static int events_probe(struct platform_device *pdev)
0103 {
0104     struct input_dev *input_dev;
0105     struct event_dev *edev;
0106     struct resource *res;
0107     unsigned int keymapnamelen;
0108     void __iomem *addr;
0109     int irq;
0110     int i;
0111     int error;
0112
0113     irq = platform_get_irq(pdev, 0);
0114     if (irq < 0)
0115         return -EINVAL;
0116
0117     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
0118     if (!res)
0119         return -EINVAL;
0120
0121     addr = devm_ioremap(&pdev->dev, res->start, 4096);
0122     if (!addr)
0123         return -ENOMEM;
0124
0125     __raw_writel(PAGE_NAME, addr + REG_SET_PAGE);
0126     keymapnamelen = __raw_readl(addr + REG_LEN);
0127
0128     edev = devm_kzalloc(&pdev->dev,
0129                 sizeof(struct event_dev) + keymapnamelen + 1,
0130                 GFP_KERNEL);
0131     if (!edev)
0132         return -ENOMEM;
0133
0134     input_dev = devm_input_allocate_device(&pdev->dev);
0135     if (!input_dev)
0136         return -ENOMEM;
0137
0138     edev->input = input_dev;
0139     edev->addr = addr;
0140     edev->irq = irq;
0141
0142     for (i = 0; i < keymapnamelen; i++)
0143         edev->name[i] = __raw_readb(edev->addr + REG_DATA + i);
0144
0145     pr_debug("%s: keymap=%s\n", __func__, edev->name);
0146
0147     input_dev->name = edev->name;
0148     input_dev->id.bustype = BUS_HOST;
0149
0150     events_import_bits(edev, input_dev->evbit, EV_SYN, EV_MAX);
0151     events_import_bits(edev, input_dev->keybit, EV_KEY, KEY_MAX);
0152     events_import_bits(edev, input_dev->relbit, EV_REL, REL_MAX);
0153     events_import_bits(edev, input_dev->absbit, EV_ABS, ABS_MAX);
0154     events_import_bits(edev, input_dev->mscbit, EV_MSC, MSC_MAX);
0155     events_import_bits(edev, input_dev->ledbit, EV_LED, LED_MAX);
0156     events_import_bits(edev, input_dev->sndbit, EV_SND, SND_MAX);
0157     events_import_bits(edev, input_dev->ffbit, EV_FF, FF_MAX);
0158     events_import_bits(edev, input_dev->swbit, EV_SW, SW_MAX);
0159
0160     events_import_abs_params(edev);
0161
0162     error = devm_request_irq(&pdev->dev, edev->irq, events_interrupt, 0,
0163                  "goldfish-events-keypad", edev);
0164     if (error)
0165         return error;
0166
0167     error = input_register_device(input_dev);
0168     if (error)
0169         return error;
0170
0171     return 0;
0172 }
0173
0174 static const struct of_device_id goldfish_events_of_match[] = {
0175     { .compatible = "google,goldfish-events-keypad", },
0176     {},
0177 };
0178 MODULE_DEVICE_TABLE(of, goldfish_events_of_match);
0179
0180 #ifdef CONFIG_ACPI
0181 static const struct acpi_device_id goldfish_events_acpi_match[] = {
0182     { "GFSH0002", 0 },
0183     { },
0184 };
0185 MODULE_DEVICE_TABLE(acpi, goldfish_events_acpi_match);
0186 #endif
0187
0188 static struct platform_driver events_driver = {
0189     .probe  = events_probe,
0190     .driver = {
0191         .name   = "goldfish_events",
0192         .of_match_table = goldfish_events_of_match,
0193         .acpi_match_table = ACPI_PTR(goldfish_events_acpi_match),
0194     },
0195 };
0196
0197 module_platform_driver(events_driver);
0198
0199 MODULE_AUTHOR("Brian Swetland");
0200 MODULE_DESCRIPTION("Goldfish Event Device");
0201 MODULE_LICENSE("GPL");