linux/drivers/media/usb/pvrusb2/pvrusb2-i2c-core.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *
 *  Copyright (C) 2005 Mike Isely <[email protected]>
 */

#include <linux/i2c.h>
#include <linux/module.h>
#include <media/i2c/ir-kbd-i2c.h>
#include "pvrusb2-i2c-core.h"
#include "pvrusb2-hdw-internal.h"
#include "pvrusb2-debug.h"
#include "pvrusb2-fx2-cmd.h"
#include "pvrusb2.h"

#define trace_i2c(...) …

/*

  This module attempts to implement a compliant I2C adapter for the pvrusb2
  device.

*/

static unsigned int i2c_scan;
module_param(i2c_scan, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(…) …;

static int ir_mode[PVR_NUM] = …;
module_param_array(…);
MODULE_PARM_DESC(…) …;

static int pvr2_disable_ir_video;
module_param_named(disable_autoload_ir_video, pvr2_disable_ir_video,
		   int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(…) …;

static int pvr2_i2c_write(struct pvr2_hdw *hdw, /* Context */
			  u8 i2c_addr,      /* I2C address we're talking to */
			  u8 *data,         /* Data to write */
			  u16 length)       /* Size of data to write */
{ … }

static int pvr2_i2c_read(struct pvr2_hdw *hdw, /* Context */
			 u8 i2c_addr,       /* I2C address we're talking to */
			 u8 *data,          /* Data to write */
			 u16 dlen,          /* Size of data to write */
			 u8 *res,           /* Where to put data we read */
			 u16 rlen)          /* Amount of data to read */
{ … }

/* This is the common low level entry point for doing I2C operations to the
   hardware. */
static int pvr2_i2c_basic_op(struct pvr2_hdw *hdw,
			     u8 i2c_addr,
			     u8 *wdata,
			     u16 wlen,
			     u8 *rdata,
			     u16 rlen)
{ … }


/* This is a special entry point for cases of I2C transaction attempts to
   the IR receiver.  The implementation here simulates the IR receiver by
   issuing a command to the FX2 firmware and using that response to return
   what the real I2C receiver would have returned.  We use this for 24xxx
   devices, where the IR receiver chip has been removed and replaced with
   FX2 related logic. */
static int i2c_24xxx_ir(struct pvr2_hdw *hdw,
			u8 i2c_addr,u8 *wdata,u16 wlen,u8 *rdata,u16 rlen)
{ … }

/* This is a special entry point that is entered if an I2C operation is
   attempted to a wm8775 chip on model 24xxx hardware.  Autodetect of this
   part doesn't work, but we know it is really there.  So let's look for
   the autodetect attempt and just return success if we see that. */
static int i2c_hack_wm8775(struct pvr2_hdw *hdw,
			   u8 i2c_addr,u8 *wdata,u16 wlen,u8 *rdata,u16 rlen)
{ … }

/* This is an entry point designed to always fail any attempt to perform a
   transfer.  We use this to cause certain I2C addresses to not be
   probed. */
static int i2c_black_hole(struct pvr2_hdw *hdw,
			   u8 i2c_addr,u8 *wdata,u16 wlen,u8 *rdata,u16 rlen)
{ … }

/* This is a special entry point that is entered if an I2C operation is
   attempted to a cx25840 chip on model 24xxx hardware.  This chip can
   sometimes wedge itself.  Worse still, when this happens msp3400 can
   falsely detect this part and then the system gets hosed up after msp3400
   gets confused and dies.  What we want to do here is try to keep msp3400
   away and also try to notice if the chip is wedged and send a warning to
   the system log. */
static int i2c_hack_cx25840(struct pvr2_hdw *hdw,
			    u8 i2c_addr,u8 *wdata,u16 wlen,u8 *rdata,u16 rlen)
{ … }

/* This is a very, very limited I2C adapter implementation.  We can only
   support what we actually know will work on the device... */
static int pvr2_i2c_xfer(struct i2c_adapter *i2c_adap,
			 struct i2c_msg msgs[],
			 int num)
{ … }

static u32 pvr2_i2c_functionality(struct i2c_adapter *adap)
{ … }

static const struct i2c_algorithm pvr2_i2c_algo_template = …;

static const struct i2c_adapter pvr2_i2c_adap_template = …;


/* Return true if device exists at given address */
static int do_i2c_probe(struct pvr2_hdw *hdw, int addr)
{ … }

static void do_i2c_scan(struct pvr2_hdw *hdw)
{ … }

static void pvr2_i2c_register_ir(struct pvr2_hdw *hdw)
{ … }

void pvr2_i2c_core_init(struct pvr2_hdw *hdw)
{ … }

void pvr2_i2c_core_done(struct pvr2_hdw *hdw)
{ … }