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/init.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/input.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/io.h>
  16 #include <linux/slab.h>
  17
  18 #include <mach/pxa930_rotary.h>
  19
  20 #define SBCR    (0x04)
  21 #define ERCR    (0x0c)
  22
  23 #define SBCR_ERSB       (1 << 5)
  24
  25 struct pxa930_rotary {
  26         struct input_dev        *input_dev;
  27         void __iomem            *mmio_base;
  28         int                     last_ercr;
  29
  30         struct pxa930_rotary_platform_data *pdata;
  31 };
  32
  33 static void clear_sbcr(struct pxa930_rotary *r)
  34 {
  35         uint32_t sbcr = __raw_readl(r->mmio_base + SBCR);
  36
  37         __raw_writel(sbcr | SBCR_ERSB, r->mmio_base + SBCR);
  38         __raw_writel(sbcr & ~SBCR_ERSB, r->mmio_base + SBCR);
  39 }
  40
  41 static irqreturn_t rotary_irq(int irq, void *dev_id)
  42 {
  43         struct pxa930_rotary *r = dev_id;
  44         struct pxa930_rotary_platform_data *pdata = r->pdata;
  45         int ercr, delta, key;
  46
  47         ercr = __raw_readl(r->mmio_base + ERCR) & 0xf;
  48         clear_sbcr(r);
  49
  50         delta = ercr - r->last_ercr;
  51         if (delta == 0)
  52                 return IRQ_HANDLED;
  53
  54         r->last_ercr = ercr;
  55
  56         if (pdata->up_key && pdata->down_key) {
  57                 key = (delta > 0) ? pdata->up_key : pdata->down_key;
  58                 input_report_key(r->input_dev, key, 1);
  59                 input_sync(r->input_dev);
  60                 input_report_key(r->input_dev, key, 0);
  61         } else
  62                 input_report_rel(r->input_dev, pdata->rel_code, delta);
  63
  64         input_sync(r->input_dev);
  65
  66         return IRQ_HANDLED;
  67 }
  68
  69 static int pxa930_rotary_open(struct input_dev *dev)
  70 {
  71         struct pxa930_rotary *r = input_get_drvdata(dev);
  72
  73         clear_sbcr(r);
  74
  75         return 0;
  76 }
  77
  78 static void pxa930_rotary_close(struct input_dev *dev)
  79 {
  80         struct pxa930_rotary *r = input_get_drvdata(dev);
  81
  82         clear_sbcr(r);
  83 }
  84
  85 static int __devinit pxa930_rotary_probe(struct platform_device *pdev)
  86 {
  87         struct pxa930_rotary_platform_data *pdata = pdev->dev.platform_data;
  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, IRQF_DISABLED,
 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 __devexit 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         platform_set_drvdata(pdev, NULL);
 185         kfree(r);
 186
 187         return 0;
 188 }
 189
 190 static struct platform_driver pxa930_rotary_driver = {
 191         .driver         = {
 192                 .name   = "pxa930-rotary",
 193                 .owner  = THIS_MODULE,
 194         },
 195         .probe          = pxa930_rotary_probe,
 196         .remove         = __devexit_p(pxa930_rotary_remove),
 197 };
 198
 199 static int __init pxa930_rotary_init(void)
 200 {
 201         return platform_driver_register(&pxa930_rotary_driver);
 202 }
 203 module_init(pxa930_rotary_init);
 204
 205 static void __exit pxa930_rotary_exit(void)
 206 {
 207         platform_driver_unregister(&pxa930_rotary_driver);
 208 }
 209 module_exit(pxa930_rotary_exit);
 210
 211 MODULE_LICENSE("GPL");
 212 MODULE_DESCRIPTION("Driver for PXA93x Enhanced Rotary Controller");
 213 MODULE_AUTHOR("Yao Yong <yaoyong@marvell.com>");