drivers/i2c/busses/i2c-hydra.c

   1 /*
   2     i2c Support for the Apple `Hydra' Mac I/O
   3
   4     Copyright (c) 1999-2004 Geert Uytterhoeven <geert@linux-m68k.org>
   5
   6     Based on i2c Support for Via Technologies 82C586B South Bridge
   7     Copyright (c) 1998, 1999 Kyösti Mälkki <kmalkki@cc.hut.fi>
   8
   9     This program is free software; you can redistribute it and/or modify
  10     it under the terms of the GNU General Public License as published by
  11     the Free Software Foundation; either version 2 of the License, or
  12     (at your option) any later version.
  13
  14     This program is distributed in the hope that it will be useful,
  15     but WITHOUT ANY WARRANTY; without even the implied warranty of
  16     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17     GNU General Public License for more details.
  18 */
  19
  20 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/pci.h>
  23 #include <linux/types.h>
  24 #include <linux/i2c.h>
  25 #include <linux/i2c-algo-bit.h>
  26 #include <linux/io.h>
  27 #include <asm/hydra.h>
  28
  29
  30 #define HYDRA_CPD_PD0   0x00000001      /* CachePD lines */
  31 #define HYDRA_CPD_PD1   0x00000002
  32 #define HYDRA_CPD_PD2   0x00000004
  33 #define HYDRA_CPD_PD3   0x00000008
  34
  35 #define HYDRA_SCLK      HYDRA_CPD_PD0
  36 #define HYDRA_SDAT      HYDRA_CPD_PD1
  37 #define HYDRA_SCLK_OE   0x00000010
  38 #define HYDRA_SDAT_OE   0x00000020
  39
  40 static inline void pdregw(void *data, u32 val)
  41 {
  42         struct Hydra *hydra = (struct Hydra *)data;
  43         writel(val, &hydra->CachePD);
  44 }
  45
  46 static inline u32 pdregr(void *data)
  47 {
  48         struct Hydra *hydra = (struct Hydra *)data;
  49         return readl(&hydra->CachePD);
  50 }
  51
  52 static void hydra_bit_setscl(void *data, int state)
  53 {
  54         u32 val = pdregr(data);
  55         if (state)
  56                 val &= ~HYDRA_SCLK_OE;
  57         else {
  58                 val &= ~HYDRA_SCLK;
  59                 val |= HYDRA_SCLK_OE;
  60         }
  61         pdregw(data, val);
  62 }
  63
  64 static void hydra_bit_setsda(void *data, int state)
  65 {
  66         u32 val = pdregr(data);
  67         if (state)
  68                 val &= ~HYDRA_SDAT_OE;
  69         else {
  70                 val &= ~HYDRA_SDAT;
  71                 val |= HYDRA_SDAT_OE;
  72         }
  73         pdregw(data, val);
  74 }
  75
  76 static int hydra_bit_getscl(void *data)
  77 {
  78         return (pdregr(data) & HYDRA_SCLK) != 0;
  79 }
  80
  81 static int hydra_bit_getsda(void *data)
  82 {
  83         return (pdregr(data) & HYDRA_SDAT) != 0;
  84 }
  85
  86 /* ------------------------------------------------------------------------ */
  87
  88 static struct i2c_algo_bit_data hydra_bit_data = {
  89         .setsda         = hydra_bit_setsda,
  90         .setscl         = hydra_bit_setscl,
  91         .getsda         = hydra_bit_getsda,
  92         .getscl         = hydra_bit_getscl,
  93         .udelay         = 5,
  94         .timeout        = HZ
  95 };
  96
  97 static struct i2c_adapter hydra_adap = {
  98         .owner          = THIS_MODULE,
  99         .name           = "Hydra i2c",
 100         .algo_data      = &hydra_bit_data,
 101 };
 102
 103 static const struct pci_device_id hydra_ids[] = {
 104         { PCI_DEVICE(PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_HYDRA) },
 105         { 0, }
 106 };
 107
 108 MODULE_DEVICE_TABLE (pci, hydra_ids);
 109
 110 static int hydra_probe(struct pci_dev *dev,
 111                                  const struct pci_device_id *id)
 112 {
 113         unsigned long base = pci_resource_start(dev, 0);
 114         int res;
 115
 116         if (!request_mem_region(base+offsetof(struct Hydra, CachePD), 4,
 117                                 hydra_adap.name))
 118                 return -EBUSY;
 119
 120         hydra_bit_data.data = pci_ioremap_bar(dev, 0);
 121         if (hydra_bit_data.data == NULL) {
 122                 release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
 123                 return -ENODEV;
 124         }
 125
 126         pdregw(hydra_bit_data.data, 0);         /* clear SCLK_OE and SDAT_OE */
 127         hydra_adap.dev.parent = &dev->dev;
 128         res = i2c_bit_add_bus(&hydra_adap);
 129         if (res < 0) {
 130                 iounmap(hydra_bit_data.data);
 131                 release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
 132                 return res;
 133         }
 134         return 0;
 135 }
 136
 137 static void hydra_remove(struct pci_dev *dev)
 138 {
 139         pdregw(hydra_bit_data.data, 0);         /* clear SCLK_OE and SDAT_OE */
 140         i2c_del_adapter(&hydra_adap);
 141         iounmap(hydra_bit_data.data);
 142         release_mem_region(pci_resource_start(dev, 0)+
 143                            offsetof(struct Hydra, CachePD), 4);
 144 }
 145
 146
 147 static struct pci_driver hydra_driver = {
 148         .name           = "hydra_smbus",
 149         .id_table       = hydra_ids,
 150         .probe          = hydra_probe,
 151         .remove         = hydra_remove,
 152 };
 153
 154 module_pci_driver(hydra_driver);
 155
 156 MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
 157 MODULE_DESCRIPTION("i2c for Apple Hydra Mac I/O");
 158 MODULE_LICENSE("GPL");