drivers/input/keyboard/pxa930_rotary.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Driver for the enhanced rotary controller on pxa930 and pxa935
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/module.h>
   8 #include <linux/interrupt.h>
   9 #include <linux/input.h>
  10 #include <linux/platform_device.h>
  11 #include <linux/io.h>
  12 #include <linux/slab.h>
  13
  14 #include <linux/platform_data/keyboard-pxa930_rotary.h>
  15
  16 #define SBCR    (0x04)
  17 #define ERCR    (0x0c)
  18
  19 #define SBCR_ERSB       (1 << 5)
  20
  21 struct pxa930_rotary {
  22         struct input_dev        *input_dev;
  23         void __iomem            *mmio_base;
  24         int                     last_ercr;
  25
  26         struct pxa930_rotary_platform_data *pdata;
  27 };
  28
  29 static void clear_sbcr(struct pxa930_rotary *r)
  30 {
  31         uint32_t sbcr = __raw_readl(r->mmio_base + SBCR);
  32
  33         __raw_writel(sbcr | SBCR_ERSB, r->mmio_base + SBCR);
  34         __raw_writel(sbcr & ~SBCR_ERSB, r->mmio_base + SBCR);
  35 }
  36
  37 static irqreturn_t rotary_irq(int irq, void *dev_id)
  38 {
  39         struct pxa930_rotary *r = dev_id;
  40         struct pxa930_rotary_platform_data *pdata = r->pdata;
  41         int ercr, delta, key;
  42
  43         ercr = __raw_readl(r->mmio_base + ERCR) & 0xf;
  44         clear_sbcr(r);
  45
  46         delta = ercr - r->last_ercr;
  47         if (delta == 0)
  48                 return IRQ_HANDLED;
  49
  50         r->last_ercr = ercr;
  51
  52         if (pdata->up_key && pdata->down_key) {
  53                 key = (delta > 0) ? pdata->up_key : pdata->down_key;
  54                 input_report_key(r->input_dev, key, 1);
  55                 input_sync(r->input_dev);
  56                 input_report_key(r->input_dev, key, 0);
  57         } else
  58                 input_report_rel(r->input_dev, pdata->rel_code, delta);
  59
  60         input_sync(r->input_dev);
  61
  62         return IRQ_HANDLED;
  63 }
  64
  65 static int pxa930_rotary_open(struct input_dev *dev)
  66 {
  67         struct pxa930_rotary *r = input_get_drvdata(dev);
  68
  69         clear_sbcr(r);
  70
  71         return 0;
  72 }
  73
  74 static void pxa930_rotary_close(struct input_dev *dev)
  75 {
  76         struct pxa930_rotary *r = input_get_drvdata(dev);
  77
  78         clear_sbcr(r);
  79 }
  80
  81 static int pxa930_rotary_probe(struct platform_device *pdev)
  82 {
  83         struct pxa930_rotary_platform_data *pdata =
  84                         dev_get_platdata(&pdev->dev);
  85         struct pxa930_rotary *r;
  86         struct input_dev *input_dev;
  87         struct resource *res;
  88         int irq;
  89         int err;
  90
  91         irq = platform_get_irq(pdev, 0);
  92         if (irq < 0)
  93                 return -ENXIO;
  94
  95         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  96         if (!res) {
  97                 dev_err(&pdev->dev, "no I/O memory defined\n");
  98                 return -ENXIO;
  99         }
 100
 101         if (!pdata) {
 102                 dev_err(&pdev->dev, "no platform data defined\n");
 103                 return -EINVAL;
 104         }
 105
 106         r = kzalloc(sizeof(struct pxa930_rotary), GFP_KERNEL);
 107         if (!r)
 108                 return -ENOMEM;
 109
 110         r->mmio_base = ioremap(res->start, resource_size(res));
 111         if (r->mmio_base == NULL) {
 112                 dev_err(&pdev->dev, "failed to remap IO memory\n");
 113                 err = -ENXIO;
 114                 goto failed_free;
 115         }
 116
 117         r->pdata = pdata;
 118         platform_set_drvdata(pdev, r);
 119
 120         /* allocate and register the input device */
 121         input_dev = input_allocate_device();
 122         if (!input_dev) {
 123                 dev_err(&pdev->dev, "failed to allocate input device\n");
 124                 err = -ENOMEM;
 125                 goto failed_free_io;
 126         }
 127
 128         input_dev->name = pdev->name;
 129         input_dev->id.bustype = BUS_HOST;
 130         input_dev->open = pxa930_rotary_open;
 131         input_dev->close = pxa930_rotary_close;
 132         input_dev->dev.parent = &pdev->dev;
 133
 134         if (pdata->up_key && pdata->down_key) {
 135                 __set_bit(pdata->up_key, input_dev->keybit);
 136                 __set_bit(pdata->down_key, input_dev->keybit);
 137                 __set_bit(EV_KEY, input_dev->evbit);
 138         } else {
 139                 __set_bit(pdata->rel_code, input_dev->relbit);
 140                 __set_bit(EV_REL, input_dev->evbit);
 141         }
 142
 143         r->input_dev = input_dev;
 144         input_set_drvdata(input_dev, r);
 145
 146         err = request_irq(irq, rotary_irq, 0,
 147                         "enhanced rotary", r);
 148         if (err) {
 149                 dev_err(&pdev->dev, "failed to request IRQ\n");
 150                 goto failed_free_input;
 151         }
 152
 153         err = input_register_device(input_dev);
 154         if (err) {
 155                 dev_err(&pdev->dev, "failed to register input device\n");
 156                 goto failed_free_irq;
 157         }
 158
 159         return 0;
 160
 161 failed_free_irq:
 162         free_irq(irq, r);
 163 failed_free_input:
 164         input_free_device(input_dev);
 165 failed_free_io:
 166         iounmap(r->mmio_base);
 167 failed_free:
 168         kfree(r);
 169         return err;
 170 }
 171
 172 static int pxa930_rotary_remove(struct platform_device *pdev)
 173 {
 174         struct pxa930_rotary *r = platform_get_drvdata(pdev);
 175
 176         free_irq(platform_get_irq(pdev, 0), r);
 177         input_unregister_device(r->input_dev);
 178         iounmap(r->mmio_base);
 179         kfree(r);
 180
 181         return 0;
 182 }
 183
 184 static struct platform_driver pxa930_rotary_driver = {
 185         .driver         = {
 186                 .name   = "pxa930-rotary",
 187         },
 188         .probe          = pxa930_rotary_probe,
 189         .remove         = pxa930_rotary_remove,
 190 };
 191 module_platform_driver(pxa930_rotary_driver);
 192
 193 MODULE_LICENSE("GPL");
 194 MODULE_DESCRIPTION("Driver for PXA93x Enhanced Rotary Controller");
 195 MODULE_AUTHOR("Yao Yong <yaoyong@marvell.com>");