drivers/video/via/via_i2c.c

   1 /*
   2  * Copyright 1998-2009 VIA Technologies, Inc. All Rights Reserved.
   3  * Copyright 2001-2008 S3 Graphics, Inc. All Rights Reserved.
   4
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public
   7  * License as published by the Free Software Foundation;
   8  * either version 2, or (at your option) any later version.
   9
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTIES OR REPRESENTATIONS; without even
  12  * the implied warranty of MERCHANTABILITY or FITNESS FOR
  13  * A PARTICULAR PURPOSE.See the GNU General Public License
  14  * for more details.
  15
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc.,
  19  * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  20  */
  21
  22 #include <linux/platform_device.h>
  23 #include <linux/delay.h>
  24 #include <linux/spinlock.h>
  25 #include <linux/module.h>
  26 #include <linux/via-core.h>
  27 #include <linux/via_i2c.h>
  28
  29 /*
  30  * There can only be one set of these, so there's no point in having
  31  * them be dynamically allocated...
  32  */
  33 #define VIAFB_NUM_I2C           5
  34 static struct via_i2c_stuff via_i2c_par[VIAFB_NUM_I2C];
  35 struct viafb_dev *i2c_vdev;  /* Passed in from core */
  36
  37 static void via_i2c_setscl(void *data, int state)
  38 {
  39         u8 val;
  40         struct via_port_cfg *adap_data = data;
  41         unsigned long flags;
  42
  43         spin_lock_irqsave(&i2c_vdev->reg_lock, flags);
  44         val = via_read_reg(adap_data->io_port, adap_data->ioport_index) & 0xF0;
  45         if (state)
  46                 val |= 0x20;
  47         else
  48                 val &= ~0x20;
  49         switch (adap_data->type) {
  50         case VIA_PORT_I2C:
  51                 val |= 0x01;
  52                 break;
  53         case VIA_PORT_GPIO:
  54                 val |= 0x80;
  55                 break;
  56         default:
  57                 printk(KERN_ERR "viafb_i2c: specify wrong i2c type.\n");
  58         }
  59         via_write_reg(adap_data->io_port, adap_data->ioport_index, val);
  60         spin_unlock_irqrestore(&i2c_vdev->reg_lock, flags);
  61 }
  62
  63 static int via_i2c_getscl(void *data)
  64 {
  65         struct via_port_cfg *adap_data = data;
  66         unsigned long flags;
  67         int ret = 0;
  68
  69         spin_lock_irqsave(&i2c_vdev->reg_lock, flags);
  70         if (via_read_reg(adap_data->io_port, adap_data->ioport_index) & 0x08)
  71                 ret = 1;
  72         spin_unlock_irqrestore(&i2c_vdev->reg_lock, flags);
  73         return ret;
  74 }
  75
  76 static int via_i2c_getsda(void *data)
  77 {
  78         struct via_port_cfg *adap_data = data;
  79         unsigned long flags;
  80         int ret = 0;
  81
  82         spin_lock_irqsave(&i2c_vdev->reg_lock, flags);
  83         if (via_read_reg(adap_data->io_port, adap_data->ioport_index) & 0x04)
  84                 ret = 1;
  85         spin_unlock_irqrestore(&i2c_vdev->reg_lock, flags);
  86         return ret;
  87 }
  88
  89 static void via_i2c_setsda(void *data, int state)
  90 {
  91         u8 val;
  92         struct via_port_cfg *adap_data = data;
  93         unsigned long flags;
  94
  95         spin_lock_irqsave(&i2c_vdev->reg_lock, flags);
  96         val = via_read_reg(adap_data->io_port, adap_data->ioport_index) & 0xF0;
  97         if (state)
  98                 val |= 0x10;
  99         else
 100                 val &= ~0x10;
 101         switch (adap_data->type) {
 102         case VIA_PORT_I2C:
 103                 val |= 0x01;
 104                 break;
 105         case VIA_PORT_GPIO:
 106                 val |= 0x40;
 107                 break;
 108         default:
 109                 printk(KERN_ERR "viafb_i2c: specify wrong i2c type.\n");
 110         }
 111         via_write_reg(adap_data->io_port, adap_data->ioport_index, val);
 112         spin_unlock_irqrestore(&i2c_vdev->reg_lock, flags);
 113 }
 114
 115 int viafb_i2c_readbyte(u8 adap, u8 slave_addr, u8 index, u8 *pdata)
 116 {
 117         int ret;
 118         u8 mm1[] = {0x00};
 119         struct i2c_msg msgs[2];
 120
 121         if (!via_i2c_par[adap].is_active)
 122                 return -ENODEV;
 123         *pdata = 0;
 124         msgs[0].flags = 0;
 125         msgs[1].flags = I2C_M_RD;
 126         msgs[0].addr = msgs[1].addr = slave_addr / 2;
 127         mm1[0] = index;
 128         msgs[0].len = 1; msgs[1].len = 1;
 129         msgs[0].buf = mm1; msgs[1].buf = pdata;
 130         ret = i2c_transfer(&via_i2c_par[adap].adapter, msgs, 2);
 131         if (ret == 2)
 132                 ret = 0;
 133         else if (ret >= 0)
 134                 ret = -EIO;
 135
 136         return ret;
 137 }
 138
 139 int viafb_i2c_writebyte(u8 adap, u8 slave_addr, u8 index, u8 data)
 140 {
 141         int ret;
 142         u8 msg[2] = { index, data };
 143         struct i2c_msg msgs;
 144
 145         if (!via_i2c_par[adap].is_active)
 146                 return -ENODEV;
 147         msgs.flags = 0;
 148         msgs.addr = slave_addr / 2;
 149         msgs.len = 2;
 150         msgs.buf = msg;
 151         ret = i2c_transfer(&via_i2c_par[adap].adapter, &msgs, 1);
 152         if (ret == 1)
 153                 ret = 0;
 154         else if (ret >= 0)
 155                 ret = -EIO;
 156
 157         return ret;
 158 }
 159
 160 int viafb_i2c_readbytes(u8 adap, u8 slave_addr, u8 index, u8 *buff, int buff_len)
 161 {
 162         int ret;
 163         u8 mm1[] = {0x00};
 164         struct i2c_msg msgs[2];
 165
 166         if (!via_i2c_par[adap].is_active)
 167                 return -ENODEV;
 168         msgs[0].flags = 0;
 169         msgs[1].flags = I2C_M_RD;
 170         msgs[0].addr = msgs[1].addr = slave_addr / 2;
 171         mm1[0] = index;
 172         msgs[0].len = 1; msgs[1].len = buff_len;
 173         msgs[0].buf = mm1; msgs[1].buf = buff;
 174         ret = i2c_transfer(&via_i2c_par[adap].adapter, msgs, 2);
 175         if (ret == 2)
 176                 ret = 0;
 177         else if (ret >= 0)
 178                 ret = -EIO;
 179
 180         return ret;
 181 }
 182
 183 /*
 184  * Allow other viafb subdevices to look up a specific adapter
 185  * by port name.
 186  */
 187 struct i2c_adapter *viafb_find_i2c_adapter(enum viafb_i2c_adap which)
 188 {
 189         struct via_i2c_stuff *stuff = &via_i2c_par[which];
 190
 191         return &stuff->adapter;
 192 }
 193 EXPORT_SYMBOL_GPL(viafb_find_i2c_adapter);
 194
 195
 196 static int create_i2c_bus(struct i2c_adapter *adapter,
 197                           struct i2c_algo_bit_data *algo,
 198                           struct via_port_cfg *adap_cfg,
 199                           struct pci_dev *pdev)
 200 {
 201         algo->setsda = via_i2c_setsda;
 202         algo->setscl = via_i2c_setscl;
 203         algo->getsda = via_i2c_getsda;
 204         algo->getscl = via_i2c_getscl;
 205         algo->udelay = 10;
 206         algo->timeout = 2;
 207         algo->data = adap_cfg;
 208
 209         sprintf(adapter->name, "viafb i2c io_port idx 0x%02x",
 210                 adap_cfg->ioport_index);
 211         adapter->owner = THIS_MODULE;
 212         adapter->id = 0x01FFFF;
 213         adapter->class = I2C_CLASS_DDC;
 214         adapter->algo_data = algo;
 215         if (pdev)
 216                 adapter->dev.parent = &pdev->dev;
 217         else
 218                 adapter->dev.parent = NULL;
 219         /* i2c_set_adapdata(adapter, adap_cfg); */
 220
 221         /* Raise SCL and SDA */
 222         via_i2c_setsda(adap_cfg, 1);
 223         via_i2c_setscl(adap_cfg, 1);
 224         udelay(20);
 225
 226         return i2c_bit_add_bus(adapter);
 227 }
 228
 229 static int viafb_i2c_probe(struct platform_device *platdev)
 230 {
 231         int i, ret;
 232         struct via_port_cfg *configs;
 233
 234         i2c_vdev = platdev->dev.platform_data;
 235         configs = i2c_vdev->port_cfg;
 236
 237         for (i = 0; i < VIAFB_NUM_PORTS; i++) {
 238                 struct via_port_cfg *adap_cfg = configs++;
 239                 struct via_i2c_stuff *i2c_stuff = &via_i2c_par[i];
 240
 241                 i2c_stuff->is_active = 0;
 242                 if (adap_cfg->type == 0 || adap_cfg->mode != VIA_MODE_I2C)
 243                         continue;
 244                 ret = create_i2c_bus(&i2c_stuff->adapter,
 245                                      &i2c_stuff->algo, adap_cfg,
 246                                 NULL); /* FIXME: PCIDEV */
 247                 if (ret < 0) {
 248                         printk(KERN_ERR "viafb: cannot create i2c bus %u:%d\n",
 249                                 i, ret);
 250                         continue;  /* Still try to make the rest */
 251                 }
 252                 i2c_stuff->is_active = 1;
 253         }
 254
 255         return 0;
 256 }
 257
 258 static int viafb_i2c_remove(struct platform_device *platdev)
 259 {
 260         int i;
 261
 262         for (i = 0; i < VIAFB_NUM_PORTS; i++) {
 263                 struct via_i2c_stuff *i2c_stuff = &via_i2c_par[i];
 264                 /*
 265                  * Only remove those entries in the array that we've
 266                  * actually used (and thus initialized algo_data)
 267                  */
 268                 if (i2c_stuff->is_active)
 269                         i2c_del_adapter(&i2c_stuff->adapter);
 270         }
 271         return 0;
 272 }
 273
 274 static struct platform_driver via_i2c_driver = {
 275         .driver = {
 276                 .name = "viafb-i2c",
 277         },
 278         .probe = viafb_i2c_probe,
 279         .remove = viafb_i2c_remove,
 280 };
 281
 282 int viafb_i2c_init(void)
 283 {
 284         return platform_driver_register(&via_i2c_driver);
 285 }
 286
 287 void viafb_i2c_exit(void)
 288 {
 289         platform_driver_unregister(&via_i2c_driver);
 290 }