linux/drivers/i2c/busses/i2c-hydra.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3    i2c Support for the Apple `Hydra' Mac I/O
   4
   5    Copyright (c) 1999-2004 Geert Uytterhoeven <geert@linux-m68k.org>
   6
   7    Based on i2c Support for Via Technologies 82C586B South Bridge
   8    Copyright (c) 1998, 1999 Kyösti Mälkki <kmalkki@cc.hut.fi>
   9
  10*/
  11
  12#include <linux/kernel.h>
  13#include <linux/module.h>
  14#include <linux/pci.h>
  15#include <linux/types.h>
  16#include <linux/i2c.h>
  17#include <linux/i2c-algo-bit.h>
  18#include <linux/io.h>
  19#include <asm/hydra.h>
  20
  21
  22#define HYDRA_CPD_PD0   0x00000001      /* CachePD lines */
  23#define HYDRA_CPD_PD1   0x00000002
  24#define HYDRA_CPD_PD2   0x00000004
  25#define HYDRA_CPD_PD3   0x00000008
  26
  27#define HYDRA_SCLK      HYDRA_CPD_PD0
  28#define HYDRA_SDAT      HYDRA_CPD_PD1
  29#define HYDRA_SCLK_OE   0x00000010
  30#define HYDRA_SDAT_OE   0x00000020
  31
  32static inline void pdregw(void *data, u32 val)
  33{
  34        struct Hydra *hydra = (struct Hydra *)data;
  35        writel(val, &hydra->CachePD);
  36}
  37
  38static inline u32 pdregr(void *data)
  39{
  40        struct Hydra *hydra = (struct Hydra *)data;
  41        return readl(&hydra->CachePD);
  42}
  43
  44static void hydra_bit_setscl(void *data, int state)
  45{
  46        u32 val = pdregr(data);
  47        if (state)
  48                val &= ~HYDRA_SCLK_OE;
  49        else {
  50                val &= ~HYDRA_SCLK;
  51                val |= HYDRA_SCLK_OE;
  52        }
  53        pdregw(data, val);
  54}
  55
  56static void hydra_bit_setsda(void *data, int state)
  57{
  58        u32 val = pdregr(data);
  59        if (state)
  60                val &= ~HYDRA_SDAT_OE;
  61        else {
  62                val &= ~HYDRA_SDAT;
  63                val |= HYDRA_SDAT_OE;
  64        }
  65        pdregw(data, val);
  66}
  67
  68static int hydra_bit_getscl(void *data)
  69{
  70        return (pdregr(data) & HYDRA_SCLK) != 0;
  71}
  72
  73static int hydra_bit_getsda(void *data)
  74{
  75        return (pdregr(data) & HYDRA_SDAT) != 0;
  76}
  77
  78/* ------------------------------------------------------------------------ */
  79
  80static struct i2c_algo_bit_data hydra_bit_data = {
  81        .setsda         = hydra_bit_setsda,
  82        .setscl         = hydra_bit_setscl,
  83        .getsda         = hydra_bit_getsda,
  84        .getscl         = hydra_bit_getscl,
  85        .udelay         = 5,
  86        .timeout        = HZ
  87};
  88
  89static struct i2c_adapter hydra_adap = {
  90        .owner          = THIS_MODULE,
  91        .name           = "Hydra i2c",
  92        .algo_data      = &hydra_bit_data,
  93};
  94
  95static const struct pci_device_id hydra_ids[] = {
  96        { PCI_DEVICE(PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_HYDRA) },
  97        { 0, }
  98};
  99
 100MODULE_DEVICE_TABLE (pci, hydra_ids);
 101
 102static int hydra_probe(struct pci_dev *dev,
 103                                 const struct pci_device_id *id)
 104{
 105        unsigned long base = pci_resource_start(dev, 0);
 106        int res;
 107
 108        if (!request_mem_region(base+offsetof(struct Hydra, CachePD), 4,
 109                                hydra_adap.name))
 110                return -EBUSY;
 111
 112        hydra_bit_data.data = pci_ioremap_bar(dev, 0);
 113        if (hydra_bit_data.data == NULL) {
 114                release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
 115                return -ENODEV;
 116        }
 117
 118        pdregw(hydra_bit_data.data, 0);         /* clear SCLK_OE and SDAT_OE */
 119        hydra_adap.dev.parent = &dev->dev;
 120        res = i2c_bit_add_bus(&hydra_adap);
 121        if (res < 0) {
 122                iounmap(hydra_bit_data.data);
 123                release_mem_region(base+offsetof(struct Hydra, CachePD), 4);
 124                return res;
 125        }
 126        return 0;
 127}
 128
 129static void hydra_remove(struct pci_dev *dev)
 130{
 131        pdregw(hydra_bit_data.data, 0);         /* clear SCLK_OE and SDAT_OE */
 132        i2c_del_adapter(&hydra_adap);
 133        iounmap(hydra_bit_data.data);
 134        release_mem_region(pci_resource_start(dev, 0)+
 135                           offsetof(struct Hydra, CachePD), 4);
 136}
 137
 138
 139static struct pci_driver hydra_driver = {
 140        .name           = "hydra_smbus",
 141        .id_table       = hydra_ids,
 142        .probe          = hydra_probe,
 143        .remove         = hydra_remove,
 144};
 145
 146module_pci_driver(hydra_driver);
 147
 148MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
 149MODULE_DESCRIPTION("i2c for Apple Hydra Mac I/O");
 150MODULE_LICENSE("GPL");
 151