drivers/i2c/busses/i2c-hydra.c

   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
  32 static inline void pdregw(void *data, u32 val)
  33 {
  34         struct Hydra *hydra = (struct Hydra *)data;
  35         writel(val, &hydra->CachePD);
  36 }
  37
  38 static inline u32 pdregr(void *data)
  39 {
  40         struct Hydra *hydra = (struct Hydra *)data;
  41         return readl(&hydra->CachePD);
  42 }
  43
  44 static 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
  56 static 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
  68 static int hydra_bit_getscl(void *data)
  69 {
  70         return (pdregr(data) & HYDRA_SCLK) != 0;
  71 }
  72
  73 static int hydra_bit_getsda(void *data)
  74 {
  75         return (pdregr(data) & HYDRA_SDAT) != 0;
  76 }
  77
  78 /* ------------------------------------------------------------------------ */
  79
  80 static 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
  89 static struct i2c_adapter hydra_adap = {
  90         .owner          = THIS_MODULE,
  91         .name           = "Hydra i2c",
  92         .algo_data      = &hydra_bit_data,
  93 };
  94
  95 static const struct pci_device_id hydra_ids[] = {
  96         { PCI_DEVICE(PCI_VENDOR_ID_APPLE, PCI_DEVICE_ID_APPLE_HYDRA) },
  97         { 0, }
  98 };
  99
 100 MODULE_DEVICE_TABLE (pci, hydra_ids);
 101
 102 static 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
 129 static 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
 139 static struct pci_driver hydra_driver = {
 140         .name           = "hydra_smbus",
 141         .id_table       = hydra_ids,
 142         .probe          = hydra_probe,
 143         .remove         = hydra_remove,
 144 };
 145
 146 module_pci_driver(hydra_driver);
 147
 148 MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
 149 MODULE_DESCRIPTION("i2c for Apple Hydra Mac I/O");
 150 MODULE_LICENSE("GPL");