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