drivers/input/mouse/pxa930_trkball.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * PXA930 track ball mouse driver
   4  *
   5  * Copyright (C) 2007 Marvell International Ltd.
   6  * 2008-02-28: Yong Yao <yaoyong@marvell.com>
   7  *             initial version
   8  */
   9
  10 #include <linux/input.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/module.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/delay.h>
  15 #include <linux/io.h>
  16 #include <linux/slab.h>
  17
  18 #include <linux/platform_data/mouse-pxa930_trkball.h>
  19
  20 /* Trackball Controller Register Definitions */
  21 #define TBCR            (0x000C)
  22 #define TBCNTR          (0x0010)
  23 #define TBSBC           (0x0014)
  24
  25 #define TBCR_TBRST      (1 << 1)
  26 #define TBCR_TBSB       (1 << 10)
  27
  28 #define TBCR_Y_FLT(n)   (((n) & 0xf) << 6)
  29 #define TBCR_X_FLT(n)   (((n) & 0xf) << 2)
  30
  31 #define TBCNTR_YM(n)    (((n) >> 24) & 0xff)
  32 #define TBCNTR_YP(n)    (((n) >> 16) & 0xff)
  33 #define TBCNTR_XM(n)    (((n) >> 8) & 0xff)
  34 #define TBCNTR_XP(n)    ((n) & 0xff)
  35
  36 #define TBSBC_TBSBC     (0x1)
  37
  38 struct pxa930_trkball {
  39         struct pxa930_trkball_platform_data *pdata;
  40
  41         /* Memory Mapped Register */
  42         struct resource *mem;
  43         void __iomem *mmio_base;
  44
  45         struct input_dev *input;
  46 };
  47
  48 static irqreturn_t pxa930_trkball_interrupt(int irq, void *dev_id)
  49 {
  50         struct pxa930_trkball *trkball = dev_id;
  51         struct input_dev *input = trkball->input;
  52         int tbcntr, x, y;
  53
  54         /* According to the spec software must read TBCNTR twice:
  55          * if the read value is the same, the reading is valid
  56          */
  57         tbcntr = __raw_readl(trkball->mmio_base + TBCNTR);
  58
  59         if (tbcntr == __raw_readl(trkball->mmio_base + TBCNTR)) {
  60                 x = (TBCNTR_XP(tbcntr) - TBCNTR_XM(tbcntr)) / 2;
  61                 y = (TBCNTR_YP(tbcntr) - TBCNTR_YM(tbcntr)) / 2;
  62
  63                 input_report_rel(input, REL_X, x);
  64                 input_report_rel(input, REL_Y, y);
  65                 input_sync(input);
  66         }
  67
  68         __raw_writel(TBSBC_TBSBC, trkball->mmio_base + TBSBC);
  69         __raw_writel(0, trkball->mmio_base + TBSBC);
  70
  71         return IRQ_HANDLED;
  72 }
  73
  74 /* For TBCR, we need to wait for a while to make sure it has been modified. */
  75 static int write_tbcr(struct pxa930_trkball *trkball, int v)
  76 {
  77         int i = 100;
  78
  79         __raw_writel(v, trkball->mmio_base + TBCR);
  80
  81         while (--i) {
  82                 if (__raw_readl(trkball->mmio_base + TBCR) == v)
  83                         break;
  84                 msleep(1);
  85         }
  86
  87         if (i == 0) {
  88                 pr_err("%s: timed out writing TBCR(%x)!\n", __func__, v);
  89                 return -ETIMEDOUT;
  90         }
  91
  92         return 0;
  93 }
  94
  95 static void pxa930_trkball_config(struct pxa930_trkball *trkball)
  96 {
  97         uint32_t tbcr;
  98
  99         /* According to spec, need to write the filters of x,y to 0xf first! */
 100         tbcr = __raw_readl(trkball->mmio_base + TBCR);
 101         write_tbcr(trkball, tbcr | TBCR_X_FLT(0xf) | TBCR_Y_FLT(0xf));
 102         write_tbcr(trkball, TBCR_X_FLT(trkball->pdata->x_filter) |
 103                             TBCR_Y_FLT(trkball->pdata->y_filter));
 104
 105         /* According to spec, set TBCR_TBRST first, before clearing it! */
 106         tbcr = __raw_readl(trkball->mmio_base + TBCR);
 107         write_tbcr(trkball, tbcr | TBCR_TBRST);
 108         write_tbcr(trkball, tbcr & ~TBCR_TBRST);
 109
 110         __raw_writel(TBSBC_TBSBC, trkball->mmio_base + TBSBC);
 111         __raw_writel(0, trkball->mmio_base + TBSBC);
 112
 113         pr_debug("%s: final TBCR=%x!\n", __func__,
 114                  __raw_readl(trkball->mmio_base + TBCR));
 115 }
 116
 117 static int pxa930_trkball_open(struct input_dev *dev)
 118 {
 119         struct pxa930_trkball *trkball = input_get_drvdata(dev);
 120
 121         pxa930_trkball_config(trkball);
 122
 123         return 0;
 124 }
 125
 126 static void pxa930_trkball_disable(struct pxa930_trkball *trkball)
 127 {
 128         uint32_t tbcr = __raw_readl(trkball->mmio_base + TBCR);
 129
 130         /* Held in reset, gate the 32-KHz input clock off */
 131         write_tbcr(trkball, tbcr | TBCR_TBRST);
 132 }
 133
 134 static void pxa930_trkball_close(struct input_dev *dev)
 135 {
 136         struct pxa930_trkball *trkball = input_get_drvdata(dev);
 137
 138         pxa930_trkball_disable(trkball);
 139 }
 140
 141 static int pxa930_trkball_probe(struct platform_device *pdev)
 142 {
 143         struct pxa930_trkball *trkball;
 144         struct input_dev *input;
 145         struct resource *res;
 146         int irq, error;
 147
 148         irq = platform_get_irq(pdev, 0);
 149         if (irq < 0)
 150                 return -ENXIO;
 151
 152         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 153         if (!res) {
 154                 dev_err(&pdev->dev, "failed to get register memory\n");
 155                 return -ENXIO;
 156         }
 157
 158         trkball = kzalloc(sizeof(struct pxa930_trkball), GFP_KERNEL);
 159         if (!trkball)
 160                 return -ENOMEM;
 161
 162         trkball->pdata = dev_get_platdata(&pdev->dev);
 163         if (!trkball->pdata) {
 164                 dev_err(&pdev->dev, "no platform data defined\n");
 165                 error = -EINVAL;
 166                 goto failed;
 167         }
 168
 169         trkball->mmio_base = ioremap(res->start, resource_size(res));
 170         if (!trkball->mmio_base) {
 171                 dev_err(&pdev->dev, "failed to ioremap registers\n");
 172                 error = -ENXIO;
 173                 goto failed;
 174         }
 175
 176         /* held the module in reset, will be enabled in open() */
 177         pxa930_trkball_disable(trkball);
 178
 179         error = request_irq(irq, pxa930_trkball_interrupt, 0,
 180                             pdev->name, trkball);
 181         if (error) {
 182                 dev_err(&pdev->dev, "failed to request irq: %d\n", error);
 183                 goto failed_free_io;
 184         }
 185
 186         platform_set_drvdata(pdev, trkball);
 187
 188         input = input_allocate_device();
 189         if (!input) {
 190                 dev_err(&pdev->dev, "failed to allocate input device\n");
 191                 error = -ENOMEM;
 192                 goto failed_free_irq;
 193         }
 194
 195         input->name = pdev->name;
 196         input->id.bustype = BUS_HOST;
 197         input->open = pxa930_trkball_open;
 198         input->close = pxa930_trkball_close;
 199         input->dev.parent = &pdev->dev;
 200         input_set_drvdata(input, trkball);
 201
 202         trkball->input = input;
 203
 204         input_set_capability(input, EV_REL, REL_X);
 205         input_set_capability(input, EV_REL, REL_Y);
 206
 207         error = input_register_device(input);
 208         if (error) {
 209                 dev_err(&pdev->dev, "unable to register input device\n");
 210                 goto failed_free_input;
 211         }
 212
 213         return 0;
 214
 215 failed_free_input:
 216         input_free_device(input);
 217 failed_free_irq:
 218         free_irq(irq, trkball);
 219 failed_free_io:
 220         iounmap(trkball->mmio_base);
 221 failed:
 222         kfree(trkball);
 223         return error;
 224 }
 225
 226 static int pxa930_trkball_remove(struct platform_device *pdev)
 227 {
 228         struct pxa930_trkball *trkball = platform_get_drvdata(pdev);
 229         int irq = platform_get_irq(pdev, 0);
 230
 231         input_unregister_device(trkball->input);
 232         free_irq(irq, trkball);
 233         iounmap(trkball->mmio_base);
 234         kfree(trkball);
 235
 236         return 0;
 237 }
 238
 239 static struct platform_driver pxa930_trkball_driver = {
 240         .driver         = {
 241                 .name   = "pxa930-trkball",
 242         },
 243         .probe          = pxa930_trkball_probe,
 244         .remove         = pxa930_trkball_remove,
 245 };
 246 module_platform_driver(pxa930_trkball_driver);
 247
 248 MODULE_AUTHOR("Yong Yao <yaoyong@marvell.com>");
 249 MODULE_DESCRIPTION("PXA930 Trackball Mouse Driver");
 250 MODULE_LICENSE("GPL");