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/init.h>
  31 #include <linux/io.h>
  32 #include <asm/hydra.h>
  33
  34
  35 #define HYDRA_CPD_PD0   0x00000001      /* CachePD lines */
  36 #define HYDRA_CPD_PD1   0x00000002
  37 #define HYDRA_CPD_PD2   0x00000004
  38 #define HYDRA_CPD_PD3   0x00000008
  39
  40 #define HYDRA_SCLK      HYDRA_CPD_PD0
  41 #define HYDRA_SDAT      HYDRA_CPD_PD1
  42 #define HYDRA_SCLK_OE   0x00000010
  43 #define HYDRA_SDAT_OE   0x00000020
  44
  45 static inline void pdregw(void *data, u32 val)
  46 {
  47         struct Hydra *hydra = (struct Hydra *)data;
  48         writel(val, &hydra->CachePD);
  49 }
  50
  51 static inline u32 pdregr(void *data)
  52 {
  53         struct Hydra *hydra = (struct Hydra *)data;
  54         return readl(&hydra->CachePD);
  55 }
  56
  57 static void hydra_bit_setscl(void *data, int state)
  58 {
  59         u32 val = pdregr(data);
  60         if (state)
  61                 val &= ~HYDRA_SCLK_OE;
  62         else {
  63                 val &= ~HYDRA_SCLK;
  64                 val |= HYDRA_SCLK_OE;
  65         }
  66         pdregw(data, val);
  67 }
  68
  69 static void hydra_bit_setsda(void *data, int state)
  70 {
  71         u32 val = pdregr(data);
  72         if (state)
  73                 val &= ~HYDRA_SDAT_OE;
  74         else {
  75                 val &= ~HYDRA_SDAT;
  76                 val |= HYDRA_SDAT_OE;
  77         }
  78         pdregw(data, val);
  79 }
  80
  81 static int hydra_bit_getscl(void *data)
  82 {
  83         return (pdregr(data) & HYDRA_SCLK) != 0;
  84 }
  85
  86 static int hydra_bit_getsda(void *data)
  87 {
  88         return (pdregr(data) & HYDRA_SDAT) != 0;
  89 }
  90
  91 /* ------------------------------------------------------------------------ */
  92
  93 static struct i2c_algo_bit_data hydra_bit_data = {
  94         .setsda         = hydra_bit_setsda,
  95         .setscl         = hydra_bit_setscl,
  96         .getsda         = hydra_bit_getsda,
  97         .getscl         = hydra_bit_getscl,
  98         .udelay         = 5,
  99         .timeout        = HZ
 100 };
 101
 102 static struct i2c_adapter hydra_adap = {
 103         .owner          = THIS_MODULE,
 104         .name           = "Hydra i2c",
 105         .algo_data      = &hydra_bit_data,
 106 };
 107
 108 static DEFINE_PCI_DEVICE_TABLE(hydra_ids) = {
 109         { PCI_DEVICE(PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_HYDRA) },
 110         { 0, }
 111 };
 112
 113 MODULE_DEVICE_TABLE (pci, hydra_ids);
 114
 115 static int hydra_probe(struct pci_dev *dev,
 116                                  const struct pci_device_id *id)
 117 {
 118         unsigned long base = pci_resource_start(dev, 0);
 119         int res;
 120
 121         if (!request_mem_region(base+offsetof(struct Hydra, CachePD), 4,
 122                                 hydra_adap.name))
 123                 return -EBUSY;
 124
 125         hydra_bit_data.data = pci_ioremap_bar(dev, 0);
 126         if (hydra_bit_data.data == NULL) {
 127                 release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
 128                 return -ENODEV;
 129         }
 130
 131         pdregw(hydra_bit_data.data, 0);         /* clear SCLK_OE and SDAT_OE */
 132         hydra_adap.dev.parent = &dev->dev;
 133         res = i2c_bit_add_bus(&hydra_adap);
 134         if (res < 0) {
 135                 iounmap(hydra_bit_data.data);
 136                 release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
 137                 return res;
 138         }
 139         return 0;
 140 }
 141
 142 static void hydra_remove(struct pci_dev *dev)
 143 {
 144         pdregw(hydra_bit_data.data, 0);         /* clear SCLK_OE and SDAT_OE */
 145         i2c_del_adapter(&hydra_adap);
 146         iounmap(hydra_bit_data.data);
 147         release_mem_region(pci_resource_start(dev, 0)+
 148                            offsetof(struct Hydra, CachePD), 4);
 149 }
 150
 151
 152 static struct pci_driver hydra_driver = {
 153         .name           = "hydra_smbus",
 154         .id_table       = hydra_ids,
 155         .probe          = hydra_probe,
 156         .remove         = hydra_remove,
 157 };
 158
 159 module_pci_driver(hydra_driver);
 160
 161 MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
 162 MODULE_DESCRIPTION("i2c for Apple Hydra Mac I/O");
 163 MODULE_LICENSE("GPL");