drivers/input/serio/ambakmi.c

   1 /*
   2  *  linux/drivers/input/serio/ambakmi.c
   3  *
   4  *  Copyright (C) 2000-2003 Deep Blue Solutions Ltd.
   5  *  Copyright (C) 2002 Russell King.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  */
  12 #include <linux/module.h>
  13 #include <linux/serio.h>
  14 #include <linux/errno.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/ioport.h>
  17 #include <linux/device.h>
  18 #include <linux/delay.h>
  19 #include <linux/slab.h>
  20 #include <linux/err.h>
  21 #include <linux/amba/bus.h>
  22 #include <linux/amba/kmi.h>
  23 #include <linux/clk.h>
  24
  25 #include <asm/io.h>
  26 #include <asm/irq.h>
  27
  28 #define KMI_BASE        (kmi->base)
  29
  30 struct amba_kmi_port {
  31         struct serio            *io;
  32         struct clk              *clk;
  33         void __iomem            *base;
  34         unsigned int            irq;
  35         unsigned int            divisor;
  36         unsigned int            open;
  37 };
  38
  39 static irqreturn_t amba_kmi_int(int irq, void *dev_id)
  40 {
  41         struct amba_kmi_port *kmi = dev_id;
  42         unsigned int status = readb(KMIIR);
  43         int handled = IRQ_NONE;
  44
  45         while (status & KMIIR_RXINTR) {
  46                 serio_interrupt(kmi->io, readb(KMIDATA), 0);
  47                 status = readb(KMIIR);
  48                 handled = IRQ_HANDLED;
  49         }
  50
  51         return handled;
  52 }
  53
  54 static int amba_kmi_write(struct serio *io, unsigned char val)
  55 {
  56         struct amba_kmi_port *kmi = io->port_data;
  57         unsigned int timeleft = 10000; /* timeout in 100ms */
  58
  59         while ((readb(KMISTAT) & KMISTAT_TXEMPTY) == 0 && --timeleft)
  60                 udelay(10);
  61
  62         if (timeleft)
  63                 writeb(val, KMIDATA);
  64
  65         return timeleft ? 0 : SERIO_TIMEOUT;
  66 }
  67
  68 static int amba_kmi_open(struct serio *io)
  69 {
  70         struct amba_kmi_port *kmi = io->port_data;
  71         unsigned int divisor;
  72         int ret;
  73
  74         ret = clk_prepare_enable(kmi->clk);
  75         if (ret)
  76                 goto out;
  77
  78         divisor = clk_get_rate(kmi->clk) / 8000000 - 1;
  79         writeb(divisor, KMICLKDIV);
  80         writeb(KMICR_EN, KMICR);
  81
  82         ret = request_irq(kmi->irq, amba_kmi_int, IRQF_SHARED, "kmi-pl050",
  83                           kmi);
  84         if (ret) {
  85                 printk(KERN_ERR "kmi: failed to claim IRQ%d\n", kmi->irq);
  86                 writeb(0, KMICR);
  87                 goto clk_disable;
  88         }
  89
  90         writeb(KMICR_EN | KMICR_RXINTREN, KMICR);
  91
  92         return 0;
  93
  94  clk_disable:
  95         clk_disable_unprepare(kmi->clk);
  96  out:
  97         return ret;
  98 }
  99
 100 static void amba_kmi_close(struct serio *io)
 101 {
 102         struct amba_kmi_port *kmi = io->port_data;
 103
 104         writeb(0, KMICR);
 105
 106         free_irq(kmi->irq, kmi);
 107         clk_disable_unprepare(kmi->clk);
 108 }
 109
 110 static int amba_kmi_probe(struct amba_device *dev,
 111         const struct amba_id *id)
 112 {
 113         struct amba_kmi_port *kmi;
 114         struct serio *io;
 115         int ret;
 116
 117         ret = amba_request_regions(dev, NULL);
 118         if (ret)
 119                 return ret;
 120
 121         kmi = kzalloc(sizeof(struct amba_kmi_port), GFP_KERNEL);
 122         io = kzalloc(sizeof(struct serio), GFP_KERNEL);
 123         if (!kmi || !io) {
 124                 ret = -ENOMEM;
 125                 goto out;
 126         }
 127
 128
 129         io->id.type     = SERIO_8042;
 130         io->write       = amba_kmi_write;
 131         io->open        = amba_kmi_open;
 132         io->close       = amba_kmi_close;
 133         strlcpy(io->name, dev_name(&dev->dev), sizeof(io->name));
 134         strlcpy(io->phys, dev_name(&dev->dev), sizeof(io->phys));
 135         io->port_data   = kmi;
 136         io->dev.parent  = &dev->dev;
 137
 138         kmi->io         = io;
 139         kmi->base       = ioremap(dev->res.start, resource_size(&dev->res));
 140         if (!kmi->base) {
 141                 ret = -ENOMEM;
 142                 goto out;
 143         }
 144
 145         kmi->clk = clk_get(&dev->dev, "KMIREFCLK");
 146         if (IS_ERR(kmi->clk)) {
 147                 ret = PTR_ERR(kmi->clk);
 148                 goto unmap;
 149         }
 150
 151         kmi->irq = dev->irq[0];
 152         amba_set_drvdata(dev, kmi);
 153
 154         serio_register_port(kmi->io);
 155         return 0;
 156
 157  unmap:
 158         iounmap(kmi->base);
 159  out:
 160         kfree(kmi);
 161         kfree(io);
 162         amba_release_regions(dev);
 163         return ret;
 164 }
 165
 166 static int amba_kmi_remove(struct amba_device *dev)
 167 {
 168         struct amba_kmi_port *kmi = amba_get_drvdata(dev);
 169
 170         serio_unregister_port(kmi->io);
 171         clk_put(kmi->clk);
 172         iounmap(kmi->base);
 173         kfree(kmi);
 174         amba_release_regions(dev);
 175         return 0;
 176 }
 177
 178 static int __maybe_unused amba_kmi_resume(struct device *dev)
 179 {
 180         struct amba_kmi_port *kmi = dev_get_drvdata(dev);
 181
 182         /* kick the serio layer to rescan this port */
 183         serio_reconnect(kmi->io);
 184
 185         return 0;
 186 }
 187
 188 static SIMPLE_DEV_PM_OPS(amba_kmi_dev_pm_ops, NULL, amba_kmi_resume);
 189
 190 static const struct amba_id amba_kmi_idtable[] = {
 191         {
 192                 .id     = 0x00041050,
 193                 .mask   = 0x000fffff,
 194         },
 195         { 0, 0 }
 196 };
 197
 198 MODULE_DEVICE_TABLE(amba, amba_kmi_idtable);
 199
 200 static struct amba_driver ambakmi_driver = {
 201         .drv            = {
 202                 .name   = "kmi-pl050",
 203                 .owner  = THIS_MODULE,
 204                 .pm     = &amba_kmi_dev_pm_ops,
 205         },
 206         .id_table       = amba_kmi_idtable,
 207         .probe          = amba_kmi_probe,
 208         .remove         = amba_kmi_remove,
 209 };
 210
 211 module_amba_driver(ambakmi_driver);
 212
 213 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
 214 MODULE_DESCRIPTION("AMBA KMI controller driver");
 215 MODULE_LICENSE("GPL");