arch/arm/mach-pxa/magician/magician_ds1wm.c

   1 /*
   2  * magician_ds1wm.c - HTC Magician DS1WM-in-AIC3 driver
   3  *
   4  * Copyright (C) 2006 Philipp Zabel <philipp.zabel@gmail.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2 of the License.
   9  */
  10
  11 #include <linux/init.h>
  12 #include <linux/module.h>
  13 #include <linux/platform_device.h>
  14
  15 #include <asm/arch/pxa-regs.h>
  16 #include <linux/io.h>
  17
  18 #include <linux/irq.h>
  19 #include <linux/interrupt.h>
  20
  21 #include <linux/clk.h>
  22 #include <asm/arch/clock.h>
  23 #include "../../../../drivers/w1/masters/ds1wm.h"
  24
  25 unsigned int __iomem *iobase;
  26
  27 static int read_register(int reg)
  28 {
  29         u16 *addr=((u16 *)(iobase+5));
  30         u8 *data=((u8 *)(iobase+6));
  31
  32         *addr |= 0x80; /* read mode */
  33         *addr = (*addr & 0xff80) | (reg & 0x7f);
  34
  35         barrier();
  36         return *data;
  37 }
  38
  39 static void write_register(int reg, int val)
  40 {
  41         u16 *addr=((u16 *)(iobase+5));
  42         u16 *data=((u16 *)(iobase+6));
  43
  44         *addr = (*addr & 0xff80) | (reg & 0x7f);
  45         *addr &= 0xff7f; /* write mode */
  46
  47         barrier();
  48         *data = (*data & 0xff00) | (val & 0xff);
  49 }
  50
  51 static struct resource magician_ds1wm_resources[] = {
  52         [0] = {
  53                 .start  = PXA_CS2_PHYS,
  54                 .end    = PXA_CS2_PHYS + 0x10,
  55                 .flags  = IORESOURCE_MEM,
  56         },
  57         [1] = {
  58                 .start  = IRQ_GPIO(107),
  59                 .end    = IRQ_GPIO(107),
  60                 .flags  = IORESOURCE_IRQ,
  61         }
  62 };
  63
  64 static struct ds1wm_platform_data magician_ds1wm_platform_data = {
  65         .bus_shift = 2,
  66 };
  67
  68 static struct platform_device *magician_ds1wm;
  69 #if 0
  70  = {
  71         .name           = "ds1wm",
  72         .id             = -1,
  73         .num_resources  = ARRAY_SIZE(magician_ds1wm_resources),
  74         .resource       = magician_ds1wm_resources,
  75         .dev =  {
  76                 .platform_data = magician_ds1wm_platform_data,
  77                 },
  78 };
  79 #endif
  80
  81 static void magician_ds1wm_enable(struct clk *clock)
  82 {
  83         int c;
  84
  85         /* I don't know how to enable the 4MHz OWM clock here */
  86
  87         c = read_register(0x28);
  88         write_register(0x28, c & 0x7f);
  89
  90         printk ("magician_ds1wm: OWM_EN low (active) %02x\n", c & 0x7f);
  91 }
  92
  93 static void magician_ds1wm_disable(struct clk *clock)
  94 {
  95         int c;
  96         c = read_register(0x28);
  97         write_register(0x28, c | 0x80);
  98
  99         printk ("magician_ds1wm: OWM_EN high (inactive) %02x\n", c | 0x80);
 100
 101         /* I don't know how to disable the 4MHz OWM clock here */
 102 }
 103
 104 static struct clk ds1wm_clk = {
 105         .name    = "ds1wm",
 106         .rate    = 4000000,
 107         .parent  = NULL,
 108         .enable  = magician_ds1wm_enable,
 109         .disable = magician_ds1wm_disable,
 110 };
 111
 112 static int __devinit magician_ds1wm_init(void)
 113 {
 114         int ret;
 115
 116         printk("Magician DS1WM driver\n");
 117         iobase = ioremap_nocache(PXA_CS2_PHYS, 0x18); // map PASIC3 for EGPIO registers
 118         set_irq_type (IRQ_GPIO(107), IRQT_RISING);
 119
 120         if (clk_register(&ds1wm_clk) < 0)
 121                 printk(KERN_ERR "failed to register DS1WM clock\n");
 122
 123         magician_ds1wm = platform_device_alloc("ds1wm", -1);
 124         if (!magician_ds1wm) {
 125                 printk("magician_ds1wm: failed to allocate platform device\n");
 126                 ret = -ENOMEM;
 127                 goto exit_unmap;
 128         }
 129
 130         magician_ds1wm->num_resources = ARRAY_SIZE(magician_ds1wm_resources);
 131         magician_ds1wm->resource = magician_ds1wm_resources;
 132         magician_ds1wm->dev.platform_data = &magician_ds1wm_platform_data;
 133         ret = platform_device_add(magician_ds1wm);
 134
 135         if (ret) {
 136                 platform_device_put(magician_ds1wm);
 137                 printk("magician_ds1wm: failed to add platform device\n");
 138         }
 139
 140         return ret;
 141
 142 exit_unmap:
 143         iounmap((void __iomem *)iobase);
 144         return ret;
 145 }
 146
 147 static void __devexit magician_ds1wm_exit(void)
 148 {
 149         platform_device_unregister(magician_ds1wm);
 150         iounmap((void __iomem *)iobase);
 151 }
 152
 153 MODULE_AUTHOR("Philipp Zabel <philipp.zabel@gmail.com>");
 154 MODULE_DESCRIPTION("DS1WM driver");
 155 MODULE_LICENSE("GPL");
 156
 157 module_init(magician_ds1wm_init);
 158 module_exit(magician_ds1wm_exit);