drivers/gpu/drm/gma500/oaktrail_hdmi_i2c.c

   1 /*
   2  * Copyright © 2010 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *      Li Peng <peng.li@intel.com>
  25  */
  26
  27 #include <linux/export.h>
  28 #include <linux/mutex.h>
  29 #include <linux/pci.h>
  30 #include <linux/i2c.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/delay.h>
  33 #include "psb_drv.h"
  34
  35 #define HDMI_READ(reg)          readl(hdmi_dev->regs + (reg))
  36 #define HDMI_WRITE(reg, val)    writel(val, hdmi_dev->regs + (reg))
  37
  38 #define HDMI_HCR        0x1000
  39 #define HCR_DETECT_HDP          (1 << 6)
  40 #define HCR_ENABLE_HDCP         (1 << 5)
  41 #define HCR_ENABLE_AUDIO        (1 << 2)
  42 #define HCR_ENABLE_PIXEL        (1 << 1)
  43 #define HCR_ENABLE_TMDS         (1 << 0)
  44 #define HDMI_HICR       0x1004
  45 #define HDMI_INTR_I2C_ERROR     (1 << 4)
  46 #define HDMI_INTR_I2C_FULL      (1 << 3)
  47 #define HDMI_INTR_I2C_DONE      (1 << 2)
  48 #define HDMI_INTR_HPD           (1 << 0)
  49 #define HDMI_HSR        0x1008
  50 #define HDMI_HISR       0x100C
  51 #define HDMI_HI2CRDB0   0x1200
  52 #define HDMI_HI2CHCR    0x1240
  53 #define HI2C_HDCP_WRITE         (0 << 2)
  54 #define HI2C_HDCP_RI_READ       (1 << 2)
  55 #define HI2C_HDCP_READ          (2 << 2)
  56 #define HI2C_EDID_READ          (3 << 2)
  57 #define HI2C_READ_CONTINUE      (1 << 1)
  58 #define HI2C_ENABLE_TRANSACTION (1 << 0)
  59
  60 #define HDMI_ICRH       0x1100
  61 #define HDMI_HI2CTDR0   0x1244
  62 #define HDMI_HI2CTDR1   0x1248
  63
  64 #define I2C_STAT_INIT           0
  65 #define I2C_READ_DONE           1
  66 #define I2C_TRANSACTION_DONE    2
  67
  68 struct hdmi_i2c_dev {
  69         struct i2c_adapter *adap;
  70         struct mutex i2c_lock;
  71         struct completion complete;
  72         int status;
  73         struct i2c_msg *msg;
  74         int buf_offset;
  75 };
  76
  77 static void hdmi_i2c_irq_enable(struct oaktrail_hdmi_dev *hdmi_dev)
  78 {
  79         u32 temp;
  80
  81         temp = HDMI_READ(HDMI_HICR);
  82         temp |= (HDMI_INTR_I2C_ERROR | HDMI_INTR_I2C_FULL | HDMI_INTR_I2C_DONE);
  83         HDMI_WRITE(HDMI_HICR, temp);
  84         HDMI_READ(HDMI_HICR);
  85 }
  86
  87 static void hdmi_i2c_irq_disable(struct oaktrail_hdmi_dev *hdmi_dev)
  88 {
  89         HDMI_WRITE(HDMI_HICR, 0x0);
  90         HDMI_READ(HDMI_HICR);
  91 }
  92
  93 static int xfer_read(struct i2c_adapter *adap, struct i2c_msg *pmsg)
  94 {
  95         struct oaktrail_hdmi_dev *hdmi_dev = i2c_get_adapdata(adap);
  96         struct hdmi_i2c_dev *i2c_dev = hdmi_dev->i2c_dev;
  97         u32 temp;
  98
  99         i2c_dev->status = I2C_STAT_INIT;
 100         i2c_dev->msg = pmsg;
 101         i2c_dev->buf_offset = 0;
 102         reinit_completion(&i2c_dev->complete);
 103
 104         /* Enable I2C transaction */
 105         temp = ((pmsg->len) << 20) | HI2C_EDID_READ | HI2C_ENABLE_TRANSACTION;
 106         HDMI_WRITE(HDMI_HI2CHCR, temp);
 107         HDMI_READ(HDMI_HI2CHCR);
 108
 109         while (i2c_dev->status != I2C_TRANSACTION_DONE)
 110                 wait_for_completion_interruptible_timeout(&i2c_dev->complete,
 111                                                                 10 * HZ);
 112
 113         return 0;
 114 }
 115
 116 static int xfer_write(struct i2c_adapter *adap, struct i2c_msg *pmsg)
 117 {
 118         /*
 119          * XXX: i2c write seems isn't useful for EDID probe, don't do anything
 120          */
 121         return 0;
 122 }
 123
 124 static int oaktrail_hdmi_i2c_access(struct i2c_adapter *adap,
 125                                 struct i2c_msg *pmsg,
 126                                 int num)
 127 {
 128         struct oaktrail_hdmi_dev *hdmi_dev = i2c_get_adapdata(adap);
 129         struct hdmi_i2c_dev *i2c_dev = hdmi_dev->i2c_dev;
 130         int i;
 131
 132         mutex_lock(&i2c_dev->i2c_lock);
 133
 134         /* Enable i2c unit */
 135         HDMI_WRITE(HDMI_ICRH, 0x00008760);
 136
 137         /* Enable irq */
 138         hdmi_i2c_irq_enable(hdmi_dev);
 139         for (i = 0; i < num; i++) {
 140                 if (pmsg->len && pmsg->buf) {
 141                         if (pmsg->flags & I2C_M_RD)
 142                                 xfer_read(adap, pmsg);
 143                         else
 144                                 xfer_write(adap, pmsg);
 145                 }
 146                 pmsg++;         /* next message */
 147         }
 148
 149         /* Disable irq */
 150         hdmi_i2c_irq_disable(hdmi_dev);
 151
 152         mutex_unlock(&i2c_dev->i2c_lock);
 153
 154         return i;
 155 }
 156
 157 static u32 oaktrail_hdmi_i2c_func(struct i2c_adapter *adapter)
 158 {
 159         return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR;
 160 }
 161
 162 static const struct i2c_algorithm oaktrail_hdmi_i2c_algorithm = {
 163         .master_xfer    = oaktrail_hdmi_i2c_access,
 164         .functionality  = oaktrail_hdmi_i2c_func,
 165 };
 166
 167 static struct i2c_adapter oaktrail_hdmi_i2c_adapter = {
 168         .name           = "oaktrail_hdmi_i2c",
 169         .nr             = 3,
 170         .owner          = THIS_MODULE,
 171         .class          = I2C_CLASS_DDC,
 172         .algo           = &oaktrail_hdmi_i2c_algorithm,
 173 };
 174
 175 static void hdmi_i2c_read(struct oaktrail_hdmi_dev *hdmi_dev)
 176 {
 177         struct hdmi_i2c_dev *i2c_dev = hdmi_dev->i2c_dev;
 178         struct i2c_msg *msg = i2c_dev->msg;
 179         u8 *buf = msg->buf;
 180         u32 temp;
 181         int i, offset;
 182
 183         offset = i2c_dev->buf_offset;
 184         for (i = 0; i < 0x10; i++) {
 185                 temp = HDMI_READ(HDMI_HI2CRDB0 + (i * 4));
 186                 memcpy(buf + (offset + i * 4), &temp, 4);
 187         }
 188         i2c_dev->buf_offset += (0x10 * 4);
 189
 190         /* clearing read buffer full intr */
 191         temp = HDMI_READ(HDMI_HISR);
 192         HDMI_WRITE(HDMI_HISR, temp | HDMI_INTR_I2C_FULL);
 193         HDMI_READ(HDMI_HISR);
 194
 195         /* continue read transaction */
 196         temp = HDMI_READ(HDMI_HI2CHCR);
 197         HDMI_WRITE(HDMI_HI2CHCR, temp | HI2C_READ_CONTINUE);
 198         HDMI_READ(HDMI_HI2CHCR);
 199
 200         i2c_dev->status = I2C_READ_DONE;
 201         return;
 202 }
 203
 204 static void hdmi_i2c_transaction_done(struct oaktrail_hdmi_dev *hdmi_dev)
 205 {
 206         struct hdmi_i2c_dev *i2c_dev = hdmi_dev->i2c_dev;
 207         u32 temp;
 208
 209         /* clear transaction done intr */
 210         temp = HDMI_READ(HDMI_HISR);
 211         HDMI_WRITE(HDMI_HISR, temp | HDMI_INTR_I2C_DONE);
 212         HDMI_READ(HDMI_HISR);
 213
 214
 215         temp = HDMI_READ(HDMI_HI2CHCR);
 216         HDMI_WRITE(HDMI_HI2CHCR, temp & ~HI2C_ENABLE_TRANSACTION);
 217         HDMI_READ(HDMI_HI2CHCR);
 218
 219         i2c_dev->status = I2C_TRANSACTION_DONE;
 220         return;
 221 }
 222
 223 static irqreturn_t oaktrail_hdmi_i2c_handler(int this_irq, void *dev)
 224 {
 225         struct oaktrail_hdmi_dev *hdmi_dev = dev;
 226         struct hdmi_i2c_dev *i2c_dev = hdmi_dev->i2c_dev;
 227         u32 stat;
 228
 229         stat = HDMI_READ(HDMI_HISR);
 230
 231         if (stat & HDMI_INTR_HPD) {
 232                 HDMI_WRITE(HDMI_HISR, stat | HDMI_INTR_HPD);
 233                 HDMI_READ(HDMI_HISR);
 234         }
 235
 236         if (stat & HDMI_INTR_I2C_FULL)
 237                 hdmi_i2c_read(hdmi_dev);
 238
 239         if (stat & HDMI_INTR_I2C_DONE)
 240                 hdmi_i2c_transaction_done(hdmi_dev);
 241
 242         complete(&i2c_dev->complete);
 243
 244         return IRQ_HANDLED;
 245 }
 246
 247 /*
 248  * choose alternate function 2 of GPIO pin 52, 53,
 249  * which is used by HDMI I2C logic
 250  */
 251 static void oaktrail_hdmi_i2c_gpio_fix(void)
 252 {
 253         void __iomem *base;
 254         unsigned int gpio_base = 0xff12c000;
 255         int gpio_len = 0x1000;
 256         u32 temp;
 257
 258         base = ioremap((resource_size_t)gpio_base, gpio_len);
 259         if (base == NULL) {
 260                 DRM_ERROR("gpio ioremap fail\n");
 261                 return;
 262         }
 263
 264         temp = readl(base + 0x44);
 265         DRM_DEBUG_DRIVER("old gpio val %x\n", temp);
 266         writel((temp | 0x00000a00), (base +  0x44));
 267         temp = readl(base + 0x44);
 268         DRM_DEBUG_DRIVER("new gpio val %x\n", temp);
 269
 270         iounmap(base);
 271 }
 272
 273 int oaktrail_hdmi_i2c_init(struct pci_dev *dev)
 274 {
 275         struct oaktrail_hdmi_dev *hdmi_dev;
 276         struct hdmi_i2c_dev *i2c_dev;
 277         int ret;
 278
 279         hdmi_dev = pci_get_drvdata(dev);
 280
 281         i2c_dev = kzalloc(sizeof(struct hdmi_i2c_dev), GFP_KERNEL);
 282         if (i2c_dev == NULL) {
 283                 DRM_ERROR("Can't allocate interface\n");
 284                 ret = -ENOMEM;
 285                 goto exit;
 286         }
 287
 288         i2c_dev->adap = &oaktrail_hdmi_i2c_adapter;
 289         i2c_dev->status = I2C_STAT_INIT;
 290         init_completion(&i2c_dev->complete);
 291         mutex_init(&i2c_dev->i2c_lock);
 292         i2c_set_adapdata(&oaktrail_hdmi_i2c_adapter, hdmi_dev);
 293         hdmi_dev->i2c_dev = i2c_dev;
 294
 295         /* Enable HDMI I2C function on gpio */
 296         oaktrail_hdmi_i2c_gpio_fix();
 297
 298         /* request irq */
 299         ret = request_irq(dev->irq, oaktrail_hdmi_i2c_handler, IRQF_SHARED,
 300                           oaktrail_hdmi_i2c_adapter.name, hdmi_dev);
 301         if (ret) {
 302                 DRM_ERROR("Failed to request IRQ for I2C controller\n");
 303                 goto err;
 304         }
 305
 306         /* Adapter registration */
 307         ret = i2c_add_numbered_adapter(&oaktrail_hdmi_i2c_adapter);
 308         return ret;
 309
 310 err:
 311         kfree(i2c_dev);
 312 exit:
 313         return ret;
 314 }
 315
 316 void oaktrail_hdmi_i2c_exit(struct pci_dev *dev)
 317 {
 318         struct oaktrail_hdmi_dev *hdmi_dev;
 319         struct hdmi_i2c_dev *i2c_dev;
 320
 321         hdmi_dev = pci_get_drvdata(dev);
 322         i2c_del_adapter(&oaktrail_hdmi_i2c_adapter);
 323
 324         i2c_dev = hdmi_dev->i2c_dev;
 325         kfree(i2c_dev);
 326         free_irq(dev->irq, hdmi_dev);
 327 }