drivers/input/mouse/pxa930_trkball.c

   1 /*
   2  * PXA930 track ball mouse driver
   3  *
   4  * Copyright (C) 2007 Marvell International Ltd.
   5  * 2008-02-28: Yong Yao <yaoyong@marvell.com>
   6  *             initial version
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License version 2 as
  10  *  published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/init.h>
  14 #include <linux/input.h>
  15 #include <linux/version.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/module.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/delay.h>
  20 #include <linux/io.h>
  21 #include <linux/slab.h>
  22
  23 #include <mach/hardware.h>
  24 #include <mach/pxa930_trkball.h>
  25
  26 /* Trackball Controller Register Definitions */
  27 #define TBCR            (0x000C)
  28 #define TBCNTR          (0x0010)
  29 #define TBSBC           (0x0014)
  30
  31 #define TBCR_TBRST      (1 << 1)
  32 #define TBCR_TBSB       (1 << 10)
  33
  34 #define TBCR_Y_FLT(n)   (((n) & 0xf) << 6)
  35 #define TBCR_X_FLT(n)   (((n) & 0xf) << 2)
  36
  37 #define TBCNTR_YM(n)    (((n) >> 24) & 0xff)
  38 #define TBCNTR_YP(n)    (((n) >> 16) & 0xff)
  39 #define TBCNTR_XM(n)    (((n) >> 8) & 0xff)
  40 #define TBCNTR_XP(n)    ((n) & 0xff)
  41
  42 #define TBSBC_TBSBC     (0x1)
  43
  44 struct pxa930_trkball {
  45         struct pxa930_trkball_platform_data *pdata;
  46
  47         /* Memory Mapped Register */
  48         struct resource *mem;
  49         void __iomem *mmio_base;
  50
  51         struct input_dev *input;
  52 };
  53
  54 static irqreturn_t pxa930_trkball_interrupt(int irq, void *dev_id)
  55 {
  56         struct pxa930_trkball *trkball = dev_id;
  57         struct input_dev *input = trkball->input;
  58         int tbcntr, x, y;
  59
  60         /* According to the spec software must read TBCNTR twice:
  61          * if the read value is the same, the reading is valid
  62          */
  63         tbcntr = __raw_readl(trkball->mmio_base + TBCNTR);
  64
  65         if (tbcntr == __raw_readl(trkball->mmio_base + TBCNTR)) {
  66                 x = (TBCNTR_XP(tbcntr) - TBCNTR_XM(tbcntr)) / 2;
  67                 y = (TBCNTR_YP(tbcntr) - TBCNTR_YM(tbcntr)) / 2;
  68
  69                 input_report_rel(input, REL_X, x);
  70                 input_report_rel(input, REL_Y, y);
  71                 input_sync(input);
  72         }
  73
  74         __raw_writel(TBSBC_TBSBC, trkball->mmio_base + TBSBC);
  75         __raw_writel(0, trkball->mmio_base + TBSBC);
  76
  77         return IRQ_HANDLED;
  78 }
  79
  80 /* For TBCR, we need to wait for a while to make sure it has been modified. */
  81 static int write_tbcr(struct pxa930_trkball *trkball, int v)
  82 {
  83         int i = 100;
  84
  85         __raw_writel(v, trkball->mmio_base + TBCR);
  86
  87         while (--i) {
  88                 if (__raw_readl(trkball->mmio_base + TBCR) == v)
  89                         break;
  90                 msleep(1);
  91         }
  92
  93         if (i == 0) {
  94                 pr_err("%s: timed out writing TBCR(%x)!\n", __func__, v);
  95                 return -ETIMEDOUT;
  96         }
  97
  98         return 0;
  99 }
 100
 101 static void pxa930_trkball_config(struct pxa930_trkball *trkball)
 102 {
 103         uint32_t tbcr;
 104
 105         /* According to spec, need to write the filters of x,y to 0xf first! */
 106         tbcr = __raw_readl(trkball->mmio_base + TBCR);
 107         write_tbcr(trkball, tbcr | TBCR_X_FLT(0xf) | TBCR_Y_FLT(0xf));
 108         write_tbcr(trkball, TBCR_X_FLT(trkball->pdata->x_filter) |
 109                             TBCR_Y_FLT(trkball->pdata->y_filter));
 110
 111         /* According to spec, set TBCR_TBRST first, before clearing it! */
 112         tbcr = __raw_readl(trkball->mmio_base + TBCR);
 113         write_tbcr(trkball, tbcr | TBCR_TBRST);
 114         write_tbcr(trkball, tbcr & ~TBCR_TBRST);
 115
 116         __raw_writel(TBSBC_TBSBC, trkball->mmio_base + TBSBC);
 117         __raw_writel(0, trkball->mmio_base + TBSBC);
 118
 119         pr_debug("%s: final TBCR=%x!\n", __func__,
 120                  __raw_readl(trkball->mmio_base + TBCR));
 121 }
 122
 123 static int pxa930_trkball_open(struct input_dev *dev)
 124 {
 125         struct pxa930_trkball *trkball = input_get_drvdata(dev);
 126
 127         pxa930_trkball_config(trkball);
 128
 129         return 0;
 130 }
 131
 132 static void pxa930_trkball_disable(struct pxa930_trkball *trkball)
 133 {
 134         uint32_t tbcr = __raw_readl(trkball->mmio_base + TBCR);
 135
 136         /* Held in reset, gate the 32-KHz input clock off */
 137         write_tbcr(trkball, tbcr | TBCR_TBRST);
 138 }
 139
 140 static void pxa930_trkball_close(struct input_dev *dev)
 141 {
 142         struct pxa930_trkball *trkball = input_get_drvdata(dev);
 143
 144         pxa930_trkball_disable(trkball);
 145 }
 146
 147 static int __devinit pxa930_trkball_probe(struct platform_device *pdev)
 148 {
 149         struct pxa930_trkball *trkball;
 150         struct input_dev *input;
 151         struct resource *res;
 152         int irq, error;
 153
 154         irq = platform_get_irq(pdev, 0);
 155         if (irq < 0) {
 156                 dev_err(&pdev->dev, "failed to get trkball irq\n");
 157                 return -ENXIO;
 158         }
 159
 160         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 161         if (!res) {
 162                 dev_err(&pdev->dev, "failed to get register memory\n");
 163                 return -ENXIO;
 164         }
 165
 166         trkball = kzalloc(sizeof(struct pxa930_trkball), GFP_KERNEL);
 167         if (!trkball)
 168                 return -ENOMEM;
 169
 170         trkball->pdata = pdev->dev.platform_data;
 171         if (!trkball->pdata) {
 172                 dev_err(&pdev->dev, "no platform data defined\n");
 173                 error = -EINVAL;
 174                 goto failed;
 175         }
 176
 177         trkball->mmio_base = ioremap_nocache(res->start, resource_size(res));
 178         if (!trkball->mmio_base) {
 179                 dev_err(&pdev->dev, "failed to ioremap registers\n");
 180                 error = -ENXIO;
 181                 goto failed;
 182         }
 183
 184         /* held the module in reset, will be enabled in open() */
 185         pxa930_trkball_disable(trkball);
 186
 187         error = request_irq(irq, pxa930_trkball_interrupt, IRQF_DISABLED,
 188                             pdev->name, trkball);
 189         if (error) {
 190                 dev_err(&pdev->dev, "failed to request irq: %d\n", error);
 191                 goto failed_free_io;
 192         }
 193
 194         platform_set_drvdata(pdev, trkball);
 195
 196         input = input_allocate_device();
 197         if (!input) {
 198                 dev_err(&pdev->dev, "failed to allocate input device\n");
 199                 error = -ENOMEM;
 200                 goto failed_free_irq;
 201         }
 202
 203         input->name = pdev->name;
 204         input->id.bustype = BUS_HOST;
 205         input->open = pxa930_trkball_open;
 206         input->close = pxa930_trkball_close;
 207         input->dev.parent = &pdev->dev;
 208         input_set_drvdata(input, trkball);
 209
 210         trkball->input = input;
 211
 212         input_set_capability(input, EV_REL, REL_X);
 213         input_set_capability(input, EV_REL, REL_Y);
 214
 215         error = input_register_device(input);
 216         if (error) {
 217                 dev_err(&pdev->dev, "unable to register input device\n");
 218                 goto failed_free_input;
 219         }
 220
 221         return 0;
 222
 223 failed_free_input:
 224         input_free_device(input);
 225 failed_free_irq:
 226         free_irq(irq, trkball);
 227 failed_free_io:
 228         iounmap(trkball->mmio_base);
 229 failed:
 230         kfree(trkball);
 231         return error;
 232 }
 233
 234 static int __devexit pxa930_trkball_remove(struct platform_device *pdev)
 235 {
 236         struct pxa930_trkball *trkball = platform_get_drvdata(pdev);
 237         int irq = platform_get_irq(pdev, 0);
 238
 239         input_unregister_device(trkball->input);
 240         free_irq(irq, trkball);
 241         iounmap(trkball->mmio_base);
 242         kfree(trkball);
 243
 244         return 0;
 245 }
 246
 247 static struct platform_driver pxa930_trkball_driver = {
 248         .driver         = {
 249                 .name   = "pxa930-trkball",
 250         },
 251         .probe          = pxa930_trkball_probe,
 252         .remove         = __devexit_p(pxa930_trkball_remove),
 253 };
 254
 255 static int __init pxa930_trkball_init(void)
 256 {
 257         return platform_driver_register(&pxa930_trkball_driver);
 258 }
 259
 260 static void __exit pxa930_trkball_exit(void)
 261 {
 262         platform_driver_unregister(&pxa930_trkball_driver);
 263 }
 264
 265 module_init(pxa930_trkball_init);
 266 module_exit(pxa930_trkball_exit);
 267
 268 MODULE_AUTHOR("Yong Yao <yaoyong@marvell.com>");
 269 MODULE_DESCRIPTION("PXA930 Trackball Mouse Driver");
 270 MODULE_LICENSE("GPL");