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     You should have received a copy of the GNU General Public License
  20     along with this program; if not, write to the Free Software
  21     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23
  24 #include <linux/kernel.h>
  25 #include <linux/module.h>
  26 #include <linux/pci.h>
  27 #include <linux/types.h>
  28 #include <linux/i2c.h>
  29 #include <linux/i2c-algo-bit.h>
  30 #include <linux/io.h>
  31 #include <asm/hydra.h>
  32
  33
  34 #define HYDRA_CPD_PD0   0x00000001      /* CachePD lines */
  35 #define HYDRA_CPD_PD1   0x00000002
  36 #define HYDRA_CPD_PD2   0x00000004
  37 #define HYDRA_CPD_PD3   0x00000008
  38
  39 #define HYDRA_SCLK      HYDRA_CPD_PD0
  40 #define HYDRA_SDAT      HYDRA_CPD_PD1
  41 #define HYDRA_SCLK_OE   0x00000010
  42 #define HYDRA_SDAT_OE   0x00000020
  43
  44 static inline void pdregw(void *data, u32 val)
  45 {
  46         struct Hydra *hydra = (struct Hydra *)data;
  47         writel(val, &hydra->CachePD);
  48 }
  49
  50 static inline u32 pdregr(void *data)
  51 {
  52         struct Hydra *hydra = (struct Hydra *)data;
  53         return readl(&hydra->CachePD);
  54 }
  55
  56 static void hydra_bit_setscl(void *data, int state)
  57 {
  58         u32 val = pdregr(data);
  59         if (state)
  60                 val &= ~HYDRA_SCLK_OE;
  61         else {
  62                 val &= ~HYDRA_SCLK;
  63                 val |= HYDRA_SCLK_OE;
  64         }
  65         pdregw(data, val);
  66 }
  67
  68 static void hydra_bit_setsda(void *data, int state)
  69 {
  70         u32 val = pdregr(data);
  71         if (state)
  72                 val &= ~HYDRA_SDAT_OE;
  73         else {
  74                 val &= ~HYDRA_SDAT;
  75                 val |= HYDRA_SDAT_OE;
  76         }
  77         pdregw(data, val);
  78 }
  79
  80 static int hydra_bit_getscl(void *data)
  81 {
  82         return (pdregr(data) & HYDRA_SCLK) != 0;
  83 }
  84
  85 static int hydra_bit_getsda(void *data)
  86 {
  87         return (pdregr(data) & HYDRA_SDAT) != 0;
  88 }
  89
  90 /* ------------------------------------------------------------------------ */
  91
  92 static struct i2c_algo_bit_data hydra_bit_data = {
  93         .setsda         = hydra_bit_setsda,
  94         .setscl         = hydra_bit_setscl,
  95         .getsda         = hydra_bit_getsda,
  96         .getscl         = hydra_bit_getscl,
  97         .udelay         = 5,
  98         .timeout        = HZ
  99 };
 100
 101 static struct i2c_adapter hydra_adap = {
 102         .owner          = THIS_MODULE,
 103         .name           = "Hydra i2c",
 104         .algo_data      = &hydra_bit_data,
 105 };
 106
 107 static const struct pci_device_id hydra_ids[] = {
 108         { PCI_DEVICE(PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_HYDRA) },
 109         { 0, }
 110 };
 111
 112 MODULE_DEVICE_TABLE (pci, hydra_ids);
 113
 114 static int hydra_probe(struct pci_dev *dev,
 115                                  const struct pci_device_id *id)
 116 {
 117         unsigned long base = pci_resource_start(dev, 0);
 118         int res;
 119
 120         if (!request_mem_region(base+offsetof(struct Hydra, CachePD), 4,
 121                                 hydra_adap.name))
 122                 return -EBUSY;
 123
 124         hydra_bit_data.data = pci_ioremap_bar(dev, 0);
 125         if (hydra_bit_data.data == NULL) {
 126                 release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
 127                 return -ENODEV;
 128         }
 129
 130         pdregw(hydra_bit_data.data, 0);         /* clear SCLK_OE and SDAT_OE */
 131         hydra_adap.dev.parent = &dev->dev;
 132         res = i2c_bit_add_bus(&hydra_adap);
 133         if (res < 0) {
 134                 iounmap(hydra_bit_data.data);
 135                 release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
 136                 return res;
 137         }
 138         return 0;
 139 }
 140
 141 static void hydra_remove(struct pci_dev *dev)
 142 {
 143         pdregw(hydra_bit_data.data, 0);         /* clear SCLK_OE and SDAT_OE */
 144         i2c_del_adapter(&hydra_adap);
 145         iounmap(hydra_bit_data.data);
 146         release_mem_region(pci_resource_start(dev, 0)+
 147                            offsetof(struct Hydra, CachePD), 4);
 148 }
 149
 150
 151 static struct pci_driver hydra_driver = {
 152         .name           = "hydra_smbus",
 153         .id_table       = hydra_ids,
 154         .probe          = hydra_probe,
 155         .remove         = hydra_remove,
 156 };
 157
 158 module_pci_driver(hydra_driver);
 159
 160 MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
 161 MODULE_DESCRIPTION("i2c for Apple Hydra Mac I/O");
 162 MODULE_LICENSE("GPL");