drivers/media/video/sn9c102/sn9c102_sensor.h

   1 /***************************************************************************
   2  * API for image sensors connected to the SN9C1xx PC Camera Controllers    *
   3  *                                                                         *
   4  * Copyright (C) 2004-2007 by Luca Risolia <luca.risolia@studio.unibo.it>  *
   5  *                                                                         *
   6  * This program is free software; you can redistribute it and/or modify    *
   7  * it under the terms of the GNU General Public License as published by    *
   8  * the Free Software Foundation; either version 2 of the License, or       *
   9  * (at your option) any later version.                                     *
  10  *                                                                         *
  11  * This program is distributed in the hope that it will be useful,         *
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of          *
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           *
  14  * GNU General Public License 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., 675 Mass Ave, Cambridge, MA 02139, USA.               *
  19  ***************************************************************************/
  20
  21 #ifndef _SN9C102_SENSOR_H_
  22 #define _SN9C102_SENSOR_H_
  23
  24 #include <linux/usb.h>
  25 #include <linux/videodev.h>
  26 #include <linux/device.h>
  27 #include <linux/stddef.h>
  28 #include <linux/errno.h>
  29 #include <asm/types.h>
  30
  31 struct sn9c102_device;
  32 struct sn9c102_sensor;
  33
  34 /*****************************************************************************/
  35
  36 /*
  37    OVERVIEW.
  38    This is a small interface that allows you to add support for any CCD/CMOS
  39    image sensors connected to the SN9C1XX bridges. The entire API is documented
  40    below. In the most general case, to support a sensor there are three steps
  41    you have to follow:
  42    1) define the main "sn9c102_sensor" structure by setting the basic fields;
  43    2) write a probing function to be called by the core module when the USB
  44       camera is recognized, then add both the USB ids and the name of that
  45       function to the two corresponding tables in sn9c102_devtable.h;
  46    3) implement the methods that you want/need (and fill the rest of the main
  47       structure accordingly).
  48    "sn9c102_pas106b.c" is an example of all this stuff. Remember that you do
  49    NOT need to touch the source code of the core module for the things to work
  50    properly, unless you find bugs or flaws in it. Finally, do not forget to
  51    read the V4L2 API for completeness.
  52 */
  53
  54 /*****************************************************************************/
  55
  56 enum sn9c102_bridge {
  57         BRIDGE_SN9C101 = 0x01,
  58         BRIDGE_SN9C102 = 0x02,
  59         BRIDGE_SN9C103 = 0x04,
  60         BRIDGE_SN9C105 = 0x08,
  61         BRIDGE_SN9C120 = 0x10,
  62 };
  63
  64 /* Return the bridge name */
  65 enum sn9c102_bridge sn9c102_get_bridge(struct sn9c102_device* cam);
  66
  67 /* Return a pointer the sensor struct attached to the camera */
  68 struct sn9c102_sensor* sn9c102_get_sensor(struct sn9c102_device* cam);
  69
  70 /* Identify a device */
  71 extern struct sn9c102_device*
  72 sn9c102_match_id(struct sn9c102_device* cam, const struct usb_device_id *id);
  73
  74 /* Attach a probed sensor to the camera. */
  75 extern void
  76 sn9c102_attach_sensor(struct sn9c102_device* cam,
  77                       struct sn9c102_sensor* sensor);
  78
  79 /*
  80    Read/write routines: they always return -1 on error, 0 or the read value
  81    otherwise. NOTE that a real read operation is not supported by the SN9C1XX
  82    chip for some of its registers. To work around this problem, a pseudo-read
  83    call is provided instead: it returns the last successfully written value
  84    on the register (0 if it has never been written), the usual -1 on error.
  85 */
  86
  87 /* The "try" I2C I/O versions are used when probing the sensor */
  88 extern int sn9c102_i2c_try_write(struct sn9c102_device*,struct sn9c102_sensor*,
  89                                  u8 address, u8 value);
  90 extern int sn9c102_i2c_try_read(struct sn9c102_device*,struct sn9c102_sensor*,
  91                                 u8 address);
  92
  93 /*
  94    These must be used if and only if the sensor doesn't implement the standard
  95    I2C protocol. There are a number of good reasons why you must use the
  96    single-byte versions of these functions: do not abuse. The first function
  97    writes n bytes, from data0 to datan, to registers 0x09 - 0x09+n of SN9C1XX
  98    chip. The second one programs the registers 0x09 and 0x10 with data0 and
  99    data1, and places the n bytes read from the sensor register table in the
 100    buffer pointed by 'buffer'. Both the functions return -1 on error; the write
 101    version returns 0 on success, while the read version returns the first read
 102    byte.
 103 */
 104 extern int sn9c102_i2c_try_raw_write(struct sn9c102_device* cam,
 105                                      struct sn9c102_sensor* sensor, u8 n,
 106                                      u8 data0, u8 data1, u8 data2, u8 data3,
 107                                      u8 data4, u8 data5);
 108 extern int sn9c102_i2c_try_raw_read(struct sn9c102_device* cam,
 109                                     struct sn9c102_sensor* sensor, u8 data0,
 110                                     u8 data1, u8 n, u8 buffer[]);
 111
 112 /* To be used after the sensor struct has been attached to the camera struct */
 113 extern int sn9c102_i2c_write(struct sn9c102_device*, u8 address, u8 value);
 114 extern int sn9c102_i2c_read(struct sn9c102_device*, u8 address);
 115
 116 /* I/O on registers in the bridge. Could be used by the sensor methods too */
 117 extern int sn9c102_pread_reg(struct sn9c102_device*, u16 index);
 118 extern int sn9c102_write_reg(struct sn9c102_device*, u8 value, u16 index);
 119 extern int sn9c102_write_regs(struct sn9c102_device*, const u8 valreg[][2],
 120                               int count);
 121 /*
 122  * Write multiple registers with constant values.  For example:
 123  * sn9c102_write_const_regs(cam, {0x00, 0x14}, {0x60, 0x17}, {0x0f, 0x18});
 124  */
 125 #define sn9c102_write_const_regs(device, data...) \
 126         ({ const static u8 _data[][2] = {data}; \
 127         sn9c102_write_regs(device, _data, ARRAY_SIZE(_data)); })
 128
 129 /*****************************************************************************/
 130
 131 enum sn9c102_i2c_sysfs_ops {
 132         SN9C102_I2C_READ = 0x01,
 133         SN9C102_I2C_WRITE = 0x02,
 134 };
 135
 136 enum sn9c102_i2c_frequency { /* sensors may support both the frequencies */
 137         SN9C102_I2C_100KHZ = 0x01,
 138         SN9C102_I2C_400KHZ = 0x02,
 139 };
 140
 141 enum sn9c102_i2c_interface {
 142         SN9C102_I2C_2WIRES,
 143         SN9C102_I2C_3WIRES,
 144 };
 145
 146 #define SN9C102_MAX_CTRLS (V4L2_CID_LASTP1-V4L2_CID_BASE+10)
 147
 148 struct sn9c102_sensor {
 149         char name[32], /* sensor name */
 150              maintainer[64]; /* name of the mantainer <email> */
 151
 152         enum sn9c102_bridge supported_bridge; /* supported SN9C1xx bridges */
 153
 154         /* Supported operations through the 'sysfs' interface */
 155         enum sn9c102_i2c_sysfs_ops sysfs_ops;
 156
 157         /*
 158            These sensor capabilities must be provided if the SN9C1XX controller
 159            needs to communicate through the sensor serial interface by using
 160            at least one of the i2c functions available.
 161         */
 162         enum sn9c102_i2c_frequency frequency;
 163         enum sn9c102_i2c_interface interface;
 164
 165         /*
 166            This identifier must be provided if the image sensor implements
 167            the standard I2C protocol.
 168         */
 169         u8 i2c_slave_id; /* reg. 0x09 */
 170
 171         /*
 172            NOTE: Where not noted,most of the functions below are not mandatory.
 173                  Set to null if you do not implement them. If implemented,
 174                  they must return 0 on success, the proper error otherwise.
 175         */
 176
 177         int (*init)(struct sn9c102_device* cam);
 178         /*
 179            This function will be called after the sensor has been attached.
 180            It should be used to initialize the sensor only, but may also
 181            configure part of the SN9C1XX chip if necessary. You don't need to
 182            setup picture settings like brightness, contrast, etc.. here, if
 183            the corrisponding controls are implemented (see below), since
 184            they are adjusted in the core driver by calling the set_ctrl()
 185            method after init(), where the arguments are the default values
 186            specified in the v4l2_queryctrl list of supported controls;
 187            Same suggestions apply for other settings, _if_ the corresponding
 188            methods are present; if not, the initialization must configure the
 189            sensor according to the default configuration structures below.
 190         */
 191
 192         struct v4l2_queryctrl qctrl[SN9C102_MAX_CTRLS];
 193         /*
 194            Optional list of default controls, defined as indicated in the
 195            V4L2 API. Menu type controls are not handled by this interface.
 196         */
 197
 198         int (*get_ctrl)(struct sn9c102_device* cam, struct v4l2_control* ctrl);
 199         int (*set_ctrl)(struct sn9c102_device* cam,
 200                         const struct v4l2_control* ctrl);
 201         /*
 202            You must implement at least the set_ctrl method if you have defined
 203            the list above. The returned value must follow the V4L2
 204            specifications for the VIDIOC_G|C_CTRL ioctls. V4L2_CID_H|VCENTER
 205            are not supported by this driver, so do not implement them. Also,
 206            you don't have to check whether the passed values are out of bounds,
 207            given that this is done by the core module.
 208         */
 209
 210         struct v4l2_cropcap cropcap;
 211         /*
 212            Think the image sensor as a grid of R,G,B monochromatic pixels
 213            disposed according to a particular Bayer pattern, which describes
 214            the complete array of pixels, from (0,0) to (xmax, ymax). We will
 215            use this coordinate system from now on. It is assumed the sensor
 216            chip can be programmed to capture/transmit a subsection of that
 217            array of pixels: we will call this subsection "active window".
 218            It is not always true that the largest achievable active window can
 219            cover the whole array of pixels. The V4L2 API defines another
 220            area called "source rectangle", which, in turn, is a subrectangle of
 221            the active window. The SN9C1XX chip is always programmed to read the
 222            source rectangle.
 223            The bounds of both the active window and the source rectangle are
 224            specified in the cropcap substructures 'bounds' and 'defrect'.
 225            By default, the source rectangle should cover the largest possible
 226            area. Again, it is not always true that the largest source rectangle
 227            can cover the entire active window, although it is a rare case for
 228            the hardware we have. The bounds of the source rectangle _must_ be
 229            multiple of 16 and must use the same coordinate system as indicated
 230            before; their centers shall align initially.
 231            If necessary, the sensor chip must be initialized during init() to
 232            set the bounds of the active sensor window; however, by default, it
 233            usually covers the largest achievable area (maxwidth x maxheight)
 234            of pixels, so no particular initialization is needed, if you have
 235            defined the correct default bounds in the structures.
 236            See the V4L2 API for further details.
 237            NOTE: once you have defined the bounds of the active window
 238                  (struct cropcap.bounds) you must not change them.anymore.
 239            Only 'bounds' and 'defrect' fields are mandatory, other fields
 240            will be ignored.
 241         */
 242
 243         int (*set_crop)(struct sn9c102_device* cam,
 244                         const struct v4l2_rect* rect);
 245         /*
 246            To be called on VIDIOC_C_SETCROP. The core module always calls a
 247            default routine which configures the appropriate SN9C1XX regs (also
 248            scaling), but you may need to override/adjust specific stuff.
 249            'rect' contains width and height values that are multiple of 16: in
 250            case you override the default function, you always have to program
 251            the chip to match those values; on error return the corresponding
 252            error code without rolling back.
 253            NOTE: in case, you must program the SN9C1XX chip to get rid of
 254                  blank pixels or blank lines at the _start_ of each line or
 255                  frame after each HSYNC or VSYNC, so that the image starts with
 256                  real RGB data (see regs 0x12, 0x13) (having set H_SIZE and,
 257                  V_SIZE you don't have to care about blank pixels or blank
 258                  lines at the end of each line or frame).
 259         */
 260
 261         struct v4l2_pix_format pix_format;
 262         /*
 263            What you have to define here are: 1) initial 'width' and 'height' of
 264            the target rectangle 2) the initial 'pixelformat', which can be
 265            either V4L2_PIX_FMT_SN9C10X, V4L2_PIX_FMT_JPEG (for ompressed video)
 266            or V4L2_PIX_FMT_SBGGR8 3) 'priv', which we'll be used to indicate
 267            the number of bits per pixel for uncompressed video, 8 or 9 (despite
 268            the current value of 'pixelformat').
 269            NOTE 1: both 'width' and 'height' _must_ be either 1/1 or 1/2 or 1/4
 270                    of cropcap.defrect.width and cropcap.defrect.height. I
 271                    suggest 1/1.
 272            NOTE 2: The initial compression quality is defined by the first bit
 273                    of reg 0x17 during the initialization of the image sensor.
 274            NOTE 3: as said above, you have to program the SN9C1XX chip to get
 275                    rid of any blank pixels, so that the output of the sensor
 276                    matches the RGB bayer sequence (i.e. BGBGBG...GRGRGR).
 277         */
 278
 279         int (*set_pix_format)(struct sn9c102_device* cam,
 280                               const struct v4l2_pix_format* pix);
 281         /*
 282            To be called on VIDIOC_S_FMT, when switching from the SBGGR8 to
 283            SN9C10X pixel format or viceversa. On error return the corresponding
 284            error code without rolling back.
 285         */
 286
 287         /*
 288            Do NOT write to the data below, it's READ ONLY. It is used by the
 289            core module to store successfully updated values of the above
 290            settings, for rollbacks..etc..in case of errors during atomic I/O
 291         */
 292         struct v4l2_queryctrl _qctrl[SN9C102_MAX_CTRLS];
 293         struct v4l2_rect _rect;
 294 };
 295
 296 /*****************************************************************************/
 297
 298 /* Private ioctl's for control settings supported by some image sensors */
 299 #define SN9C102_V4L2_CID_DAC_MAGNITUDE (V4L2_CID_PRIVATE_BASE + 0)
 300 #define SN9C102_V4L2_CID_GREEN_BALANCE (V4L2_CID_PRIVATE_BASE + 1)
 301 #define SN9C102_V4L2_CID_RESET_LEVEL (V4L2_CID_PRIVATE_BASE + 2)
 302 #define SN9C102_V4L2_CID_PIXEL_BIAS_VOLTAGE (V4L2_CID_PRIVATE_BASE + 3)
 303 #define SN9C102_V4L2_CID_GAMMA (V4L2_CID_PRIVATE_BASE + 4)
 304 #define SN9C102_V4L2_CID_BAND_FILTER (V4L2_CID_PRIVATE_BASE + 5)
 305 #define SN9C102_V4L2_CID_BRIGHT_LEVEL (V4L2_CID_PRIVATE_BASE + 6)
 306
 307 #endif /* _SN9C102_SENSOR_H_ */