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