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linux/drivers/gpu/drm/drm_dp_i2c_helper.c
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from  to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00

209 lines
5.3 KiB
C

/*
* Copyright © 2009 Keith Packard
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
* the above copyright notice appear in all copies and that both that copyright
* notice and this permission notice appear in supporting documentation, and
* that the name of the copyright holders not be used in advertising or
* publicity pertaining to distribution of the software without specific,
* written prior permission. The copyright holders make no representations
* about the suitability of this software for any purpose. It is provided "as
* is" without express or implied warranty.
*
* THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
* EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
* DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
* OF THIS SOFTWARE.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/i2c.h>
#include "drm_dp_helper.h"
#include "drmP.h"
/* Run a single AUX_CH I2C transaction, writing/reading data as necessary */
static int
i2c_algo_dp_aux_transaction(struct i2c_adapter *adapter, int mode,
uint8_t write_byte, uint8_t *read_byte)
{
struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data;
int ret;
ret = (*algo_data->aux_ch)(adapter, mode,
write_byte, read_byte);
return ret;
}
/*
* I2C over AUX CH
*/
/*
* Send the address. If the I2C link is running, this 'restarts'
* the connection with the new address, this is used for doing
* a write followed by a read (as needed for DDC)
*/
static int
i2c_algo_dp_aux_address(struct i2c_adapter *adapter, u16 address, bool reading)
{
struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data;
int mode = MODE_I2C_START;
int ret;
if (reading)
mode |= MODE_I2C_READ;
else
mode |= MODE_I2C_WRITE;
algo_data->address = address;
algo_data->running = true;
ret = i2c_algo_dp_aux_transaction(adapter, mode, 0, NULL);
return ret;
}
/*
* Stop the I2C transaction. This closes out the link, sending
* a bare address packet with the MOT bit turned off
*/
static void
i2c_algo_dp_aux_stop(struct i2c_adapter *adapter, bool reading)
{
struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data;
int mode = MODE_I2C_STOP;
if (reading)
mode |= MODE_I2C_READ;
else
mode |= MODE_I2C_WRITE;
if (algo_data->running) {
(void) i2c_algo_dp_aux_transaction(adapter, mode, 0, NULL);
algo_data->running = false;
}
}
/*
* Write a single byte to the current I2C address, the
* the I2C link must be running or this returns -EIO
*/
static int
i2c_algo_dp_aux_put_byte(struct i2c_adapter *adapter, u8 byte)
{
struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data;
int ret;
if (!algo_data->running)
return -EIO;
ret = i2c_algo_dp_aux_transaction(adapter, MODE_I2C_WRITE, byte, NULL);
return ret;
}
/*
* Read a single byte from the current I2C address, the
* I2C link must be running or this returns -EIO
*/
static int
i2c_algo_dp_aux_get_byte(struct i2c_adapter *adapter, u8 *byte_ret)
{
struct i2c_algo_dp_aux_data *algo_data = adapter->algo_data;
int ret;
if (!algo_data->running)
return -EIO;
ret = i2c_algo_dp_aux_transaction(adapter, MODE_I2C_READ, 0, byte_ret);
return ret;
}
static int
i2c_algo_dp_aux_xfer(struct i2c_adapter *adapter,
struct i2c_msg *msgs,
int num)
{
int ret = 0;
bool reading = false;
int m;
int b;
for (m = 0; m < num; m++) {
u16 len = msgs[m].len;
u8 *buf = msgs[m].buf;
reading = (msgs[m].flags & I2C_M_RD) != 0;
ret = i2c_algo_dp_aux_address(adapter, msgs[m].addr, reading);
if (ret < 0)
break;
if (reading) {
for (b = 0; b < len; b++) {
ret = i2c_algo_dp_aux_get_byte(adapter, &buf[b]);
if (ret < 0)
break;
}
} else {
for (b = 0; b < len; b++) {
ret = i2c_algo_dp_aux_put_byte(adapter, buf[b]);
if (ret < 0)
break;
}
}
if (ret < 0)
break;
}
if (ret >= 0)
ret = num;
i2c_algo_dp_aux_stop(adapter, reading);
DRM_DEBUG_KMS("dp_aux_xfer return %d\n", ret);
return ret;
}
static u32
i2c_algo_dp_aux_functionality(struct i2c_adapter *adapter)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
I2C_FUNC_SMBUS_READ_BLOCK_DATA |
I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
I2C_FUNC_10BIT_ADDR;
}
static const struct i2c_algorithm i2c_dp_aux_algo = {
.master_xfer = i2c_algo_dp_aux_xfer,
.functionality = i2c_algo_dp_aux_functionality,
};
static void
i2c_dp_aux_reset_bus(struct i2c_adapter *adapter)
{
(void) i2c_algo_dp_aux_address(adapter, 0, false);
(void) i2c_algo_dp_aux_stop(adapter, false);
}
static int
i2c_dp_aux_prepare_bus(struct i2c_adapter *adapter)
{
adapter->algo = &i2c_dp_aux_algo;
adapter->retries = 3;
i2c_dp_aux_reset_bus(adapter);
return 0;
}
int
i2c_dp_aux_add_bus(struct i2c_adapter *adapter)
{
int error;
error = i2c_dp_aux_prepare_bus(adapter);
if (error)
return error;
error = i2c_add_adapter(adapter);
return error;
}
EXPORT_SYMBOL(i2c_dp_aux_add_bus);