drivers/input/keyboard/pxa930_rotary.c

   1 /*
   2  * Driver for the enhanced rotary controller on pxa930 and pxa935
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/module.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/input.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/io.h>
  15 #include <linux/slab.h>
  16
  17 #include <linux/platform_data/keyboard-pxa930_rotary.h>
  18
  19 #define SBCR    (0x04)
  20 #define ERCR    (0x0c)
  21
  22 #define SBCR_ERSB       (1 << 5)
  23
  24 struct pxa930_rotary {
  25         struct input_dev        *input_dev;
  26         void __iomem            *mmio_base;
  27         int                     last_ercr;
  28
  29         struct pxa930_rotary_platform_data *pdata;
  30 };
  31
  32 static void clear_sbcr(struct pxa930_rotary *r)
  33 {
  34         uint32_t sbcr = __raw_readl(r->mmio_base + SBCR);
  35
  36         __raw_writel(sbcr | SBCR_ERSB, r->mmio_base + SBCR);
  37         __raw_writel(sbcr & ~SBCR_ERSB, r->mmio_base + SBCR);
  38 }
  39
  40 static irqreturn_t rotary_irq(int irq, void *dev_id)
  41 {
  42         struct pxa930_rotary *r = dev_id;
  43         struct pxa930_rotary_platform_data *pdata = r->pdata;
  44         int ercr, delta, key;
  45
  46         ercr = __raw_readl(r->mmio_base + ERCR) & 0xf;
  47         clear_sbcr(r);
  48
  49         delta = ercr - r->last_ercr;
  50         if (delta == 0)
  51                 return IRQ_HANDLED;
  52
  53         r->last_ercr = ercr;
  54
  55         if (pdata->up_key && pdata->down_key) {
  56                 key = (delta > 0) ? pdata->up_key : pdata->down_key;
  57                 input_report_key(r->input_dev, key, 1);
  58                 input_sync(r->input_dev);
  59                 input_report_key(r->input_dev, key, 0);
  60         } else
  61                 input_report_rel(r->input_dev, pdata->rel_code, delta);
  62
  63         input_sync(r->input_dev);
  64
  65         return IRQ_HANDLED;
  66 }
  67
  68 static int pxa930_rotary_open(struct input_dev *dev)
  69 {
  70         struct pxa930_rotary *r = input_get_drvdata(dev);
  71
  72         clear_sbcr(r);
  73
  74         return 0;
  75 }
  76
  77 static void pxa930_rotary_close(struct input_dev *dev)
  78 {
  79         struct pxa930_rotary *r = input_get_drvdata(dev);
  80
  81         clear_sbcr(r);
  82 }
  83
  84 static int pxa930_rotary_probe(struct platform_device *pdev)
  85 {
  86         struct pxa930_rotary_platform_data *pdata =
  87                         dev_get_platdata(&pdev->dev);
  88         struct pxa930_rotary *r;
  89         struct input_dev *input_dev;
  90         struct resource *res;
  91         int irq;
  92         int err;
  93
  94         irq = platform_get_irq(pdev, 0);
  95         if (irq < 0) {
  96                 dev_err(&pdev->dev, "no irq for rotary controller\n");
  97                 return -ENXIO;
  98         }
  99
 100         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 101         if (!res) {
 102                 dev_err(&pdev->dev, "no I/O memory defined\n");
 103                 return -ENXIO;
 104         }
 105
 106         if (!pdata) {
 107                 dev_err(&pdev->dev, "no platform data defined\n");
 108                 return -EINVAL;
 109         }
 110
 111         r = kzalloc(sizeof(struct pxa930_rotary), GFP_KERNEL);
 112         if (!r)
 113                 return -ENOMEM;
 114
 115         r->mmio_base = ioremap_nocache(res->start, resource_size(res));
 116         if (r->mmio_base == NULL) {
 117                 dev_err(&pdev->dev, "failed to remap IO memory\n");
 118                 err = -ENXIO;
 119                 goto failed_free;
 120         }
 121
 122         r->pdata = pdata;
 123         platform_set_drvdata(pdev, r);
 124
 125         /* allocate and register the input device */
 126         input_dev = input_allocate_device();
 127         if (!input_dev) {
 128                 dev_err(&pdev->dev, "failed to allocate input device\n");
 129                 err = -ENOMEM;
 130                 goto failed_free_io;
 131         }
 132
 133         input_dev->name = pdev->name;
 134         input_dev->id.bustype = BUS_HOST;
 135         input_dev->open = pxa930_rotary_open;
 136         input_dev->close = pxa930_rotary_close;
 137         input_dev->dev.parent = &pdev->dev;
 138
 139         if (pdata->up_key && pdata->down_key) {
 140                 __set_bit(pdata->up_key, input_dev->keybit);
 141                 __set_bit(pdata->down_key, input_dev->keybit);
 142                 __set_bit(EV_KEY, input_dev->evbit);
 143         } else {
 144                 __set_bit(pdata->rel_code, input_dev->relbit);
 145                 __set_bit(EV_REL, input_dev->evbit);
 146         }
 147
 148         r->input_dev = input_dev;
 149         input_set_drvdata(input_dev, r);
 150
 151         err = request_irq(irq, rotary_irq, 0,
 152                         "enhanced rotary", r);
 153         if (err) {
 154                 dev_err(&pdev->dev, "failed to request IRQ\n");
 155                 goto failed_free_input;
 156         }
 157
 158         err = input_register_device(input_dev);
 159         if (err) {
 160                 dev_err(&pdev->dev, "failed to register input device\n");
 161                 goto failed_free_irq;
 162         }
 163
 164         return 0;
 165
 166 failed_free_irq:
 167         free_irq(irq, r);
 168 failed_free_input:
 169         input_free_device(input_dev);
 170 failed_free_io:
 171         iounmap(r->mmio_base);
 172 failed_free:
 173         kfree(r);
 174         return err;
 175 }
 176
 177 static int pxa930_rotary_remove(struct platform_device *pdev)
 178 {
 179         struct pxa930_rotary *r = platform_get_drvdata(pdev);
 180
 181         free_irq(platform_get_irq(pdev, 0), r);
 182         input_unregister_device(r->input_dev);
 183         iounmap(r->mmio_base);
 184         kfree(r);
 185
 186         return 0;
 187 }
 188
 189 static struct platform_driver pxa930_rotary_driver = {
 190         .driver         = {
 191                 .name   = "pxa930-rotary",
 192         },
 193         .probe          = pxa930_rotary_probe,
 194         .remove         = pxa930_rotary_remove,
 195 };
 196 module_platform_driver(pxa930_rotary_driver);
 197
 198 MODULE_LICENSE("GPL");
 199 MODULE_DESCRIPTION("Driver for PXA93x Enhanced Rotary Controller");
 200 MODULE_AUTHOR("Yao Yong <yaoyong@marvell.com>");