Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-12-26 12:52:30 +00:00
Code Issues Packages Projects Releases Wiki Activity
305180bc05
linux/drivers/media/common/saa7146/saa7146_i2c.c
Greg Kroah-Hartman b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license 
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00

425 lines
12 KiB
C
Raw Blame History

// SPDX-License-Identifier: GPL-2.0
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <media/drv-intf/saa7146_vv.h>
static u32 saa7146_i2c_func(struct i2c_adapter *adapter)
{
/* DEB_I2C("'%s'\n", adapter->name); */
return I2C_FUNC_I2C
| I2C_FUNC_SMBUS_QUICK
| I2C_FUNC_SMBUS_READ_BYTE | I2C_FUNC_SMBUS_WRITE_BYTE
| I2C_FUNC_SMBUS_READ_BYTE_DATA | I2C_FUNC_SMBUS_WRITE_BYTE_DATA;
}
/* this function returns the status-register of our i2c-device */
static inline u32 saa7146_i2c_status(struct saa7146_dev *dev)
{
u32 iicsta = saa7146_read(dev, I2C_STATUS);
/* DEB_I2C("status: 0x%08x\n", iicsta); */
return iicsta;
}
/* this function runs through the i2c-messages and prepares the data to be
sent through the saa7146. have a look at the specifications p. 122 ff
to understand this. it returns the number of u32s to send, or -1
in case of an error. */
static int saa7146_i2c_msg_prepare(const struct i2c_msg *m, int num, __le32 *op)
{
int h1, h2;
int i, j, addr;
int mem = 0, op_count = 0;
/* first determine size of needed memory */
for(i = 0; i < num; i++) {
mem += m[i].len + 1;
}
/* worst case: we need one u32 for three bytes to be send
plus one extra byte to address the device */
mem = 1 + ((mem-1) / 3);
/* we assume that op points to a memory of at least
* SAA7146_I2C_MEM bytes size. if we exceed this limit...
*/
if ((4 * mem) > SAA7146_I2C_MEM) {
/* DEB_I2C("cannot prepare i2c-message\n"); */
return -ENOMEM;
}
/* be careful: clear out the i2c-mem first */
memset(op,0,sizeof(__le32)*mem);
/* loop through all messages */
for(i = 0; i < num; i++) {
/* insert the address of the i2c-slave.
note: we get 7 bit i2c-addresses,
so we have to perform a translation */
addr = (m[i].addr*2) + ( (0 != (m[i].flags & I2C_M_RD)) ? 1 : 0);
h1 = op_count/3; h2 = op_count%3;
op[h1] |= cpu_to_le32( (u8)addr << ((3-h2)*8));
op[h1] |= cpu_to_le32(SAA7146_I2C_START << ((3-h2)*2));
op_count++;
/* loop through all bytes of message i */
for(j = 0; j < m[i].len; j++) {
/* insert the data bytes */
h1 = op_count/3; h2 = op_count%3;
op[h1] |= cpu_to_le32( (u32)((u8)m[i].buf[j]) << ((3-h2)*8));
op[h1] |= cpu_to_le32( SAA7146_I2C_CONT << ((3-h2)*2));
op_count++;
}
}
/* have a look at the last byte inserted:
if it was: ...CONT change it to ...STOP */
h1 = (op_count-1)/3; h2 = (op_count-1)%3;
if ( SAA7146_I2C_CONT == (0x3 & (le32_to_cpu(op[h1]) >> ((3-h2)*2))) ) {
op[h1] &= ~cpu_to_le32(0x2 << ((3-h2)*2));
op[h1] |= cpu_to_le32(SAA7146_I2C_STOP << ((3-h2)*2));
}
/* return the number of u32s to send */
return mem;
}
/* this functions loops through all i2c-messages. normally, it should determine
which bytes were read through the adapter and write them back to the corresponding
i2c-message. but instead, we simply write back all bytes.
fixme: this could be improved. */
static int saa7146_i2c_msg_cleanup(const struct i2c_msg *m, int num, __le32 *op)
{
int i, j;
int op_count = 0;
/* loop through all messages */
for(i = 0; i < num; i++) {
op_count++;
/* loop through all bytes of message i */
for(j = 0; j < m[i].len; j++) {
/* write back all bytes that could have been read */
m[i].buf[j] = (le32_to_cpu(op[op_count/3]) >> ((3-(op_count%3))*8));
op_count++;
}
}
return 0;
}
/* this functions resets the i2c-device and returns 0 if everything was fine, otherwise -1 */
static int saa7146_i2c_reset(struct saa7146_dev *dev)
{
/* get current status */
u32 status = saa7146_i2c_status(dev);
/* clear registers for sure */
saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
saa7146_write(dev, I2C_TRANSFER, 0);
/* check if any operation is still in progress */
if ( 0 != ( status & SAA7146_I2C_BUSY) ) {
/* yes, kill ongoing operation */
DEB_I2C("busy_state detected\n");
/* set "ABORT-OPERATION"-bit (bit 7)*/
saa7146_write(dev, I2C_STATUS, (dev->i2c_bitrate | MASK_07));
saa7146_write(dev, MC2, (MASK_00 | MASK_16));
msleep(SAA7146_I2C_DELAY);
/* clear all error-bits pending; this is needed because p.123, note 1 */
saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
saa7146_write(dev, MC2, (MASK_00 | MASK_16));
msleep(SAA7146_I2C_DELAY);
}
/* check if any error is (still) present. (this can be necessary because p.123, note 1) */
status = saa7146_i2c_status(dev);
if ( dev->i2c_bitrate != status ) {
DEB_I2C("error_state detected. status:0x%08x\n", status);
/* Repeat the abort operation. This seems to be necessary
after serious protocol errors caused by e.g. the SAA7740 */
saa7146_write(dev, I2C_STATUS, (dev->i2c_bitrate | MASK_07));
saa7146_write(dev, MC2, (MASK_00 | MASK_16));
msleep(SAA7146_I2C_DELAY);
/* clear all error-bits pending */
saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
saa7146_write(dev, MC2, (MASK_00 | MASK_16));
msleep(SAA7146_I2C_DELAY);
/* the data sheet says it might be necessary to clear the status
twice after an abort */
saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
saa7146_write(dev, MC2, (MASK_00 | MASK_16));
msleep(SAA7146_I2C_DELAY);
}
/* if any error is still present, a fatal error has occurred ... */
status = saa7146_i2c_status(dev);
if ( dev->i2c_bitrate != status ) {
DEB_I2C("fatal error. status:0x%08x\n", status);
return -1;
}
return 0;
}
/* this functions writes out the data-byte 'dword' to the i2c-device.
it returns 0 if ok, -1 if the transfer failed, -2 if the transfer
failed badly (e.g. address error) */
static int saa7146_i2c_writeout(struct saa7146_dev *dev, __le32 *dword, int short_delay)
{
u32 status = 0, mc2 = 0;
int trial = 0;
unsigned long timeout;
/* write out i2c-command */
DEB_I2C("before: 0x%08x (status: 0x%08x), %d\n",
*dword, saa7146_read(dev, I2C_STATUS), dev->i2c_op);
if( 0 != (SAA7146_USE_I2C_IRQ & dev->ext->flags)) {
saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
saa7146_write(dev, I2C_TRANSFER, le32_to_cpu(*dword));
dev->i2c_op = 1;
SAA7146_ISR_CLEAR(dev, MASK_16|MASK_17);
SAA7146_IER_ENABLE(dev, MASK_16|MASK_17);
saa7146_write(dev, MC2, (MASK_00 | MASK_16));
timeout = HZ/100 + 1; /* 10ms */
timeout = wait_event_interruptible_timeout(dev->i2c_wq, dev->i2c_op == 0, timeout);
if (timeout == -ERESTARTSYS || dev->i2c_op) {
SAA7146_IER_DISABLE(dev, MASK_16|MASK_17);
SAA7146_ISR_CLEAR(dev, MASK_16|MASK_17);
if (timeout == -ERESTARTSYS)
/* a signal arrived */
return -ERESTARTSYS;
pr_warn("%s %s [irq]: timed out waiting for end of xfer\n",
dev->name, __func__);
return -EIO;
}
status = saa7146_read(dev, I2C_STATUS);
} else {
saa7146_write(dev, I2C_STATUS, dev->i2c_bitrate);
saa7146_write(dev, I2C_TRANSFER, le32_to_cpu(*dword));
saa7146_write(dev, MC2, (MASK_00 | MASK_16));
/* do not poll for i2c-status before upload is complete */
timeout = jiffies + HZ/100 + 1; /* 10ms */
while(1) {
mc2 = (saa7146_read(dev, MC2) & 0x1);
if( 0 != mc2 ) {
break;
}
if (time_after(jiffies,timeout)) {
pr_warn("%s %s: timed out waiting for MC2\n",
dev->name, __func__);
return -EIO;
}
}
/* wait until we get a transfer done or error */
timeout = jiffies + HZ/100 + 1; /* 10ms */
/* first read usually delivers bogus results... */
saa7146_i2c_status(dev);
while(1) {
status = saa7146_i2c_status(dev);
if ((status & 0x3) != 1)
break;
if (time_after(jiffies,timeout)) {
/* this is normal when probing the bus
* (no answer from nonexisistant device...)
*/
pr_warn("%s %s [poll]: timed out waiting for end of xfer\n",
dev->name, __func__);
return -EIO;
}
if (++trial < 50 && short_delay)
udelay(10);
else
msleep(1);
}
}
/* give a detailed status report */
if ( 0 != (status & (SAA7146_I2C_SPERR | SAA7146_I2C_APERR |
SAA7146_I2C_DTERR | SAA7146_I2C_DRERR |
SAA7146_I2C_AL | SAA7146_I2C_ERR |
SAA7146_I2C_BUSY)) ) {
if ( 0 == (status & SAA7146_I2C_ERR) ||
0 == (status & SAA7146_I2C_BUSY) ) {
/* it may take some time until ERR goes high - ignore */
DEB_I2C("unexpected i2c status %04x\n", status);
}
if( 0 != (status & SAA7146_I2C_SPERR) ) {
DEB_I2C("error due to invalid start/stop condition\n");
}
if( 0 != (status & SAA7146_I2C_DTERR) ) {
DEB_I2C("error in data transmission\n");
}
if( 0 != (status & SAA7146_I2C_DRERR) ) {
DEB_I2C("error when receiving data\n");
}
if( 0 != (status & SAA7146_I2C_AL) ) {
DEB_I2C("error because arbitration lost\n");
}
/* we handle address-errors here */
if( 0 != (status & SAA7146_I2C_APERR) ) {
DEB_I2C("error in address phase\n");
return -EREMOTEIO;
}
return -EIO;
}
/* read back data, just in case we were reading ... */
*dword = cpu_to_le32(saa7146_read(dev, I2C_TRANSFER));
DEB_I2C("after: 0x%08x\n", *dword);
return 0;
}
static int saa7146_i2c_transfer(struct saa7146_dev *dev, const struct i2c_msg *msgs, int num, int retries)
{
int i = 0, count = 0;
__le32 *buffer = dev->d_i2c.cpu_addr;
int err = 0;
int short_delay = 0;
if (mutex_lock_interruptible(&dev->i2c_lock))
return -ERESTARTSYS;
for(i=0;i<num;i++) {
DEB_I2C("msg:%d/%d\n", i+1, num);
}
/* prepare the message(s), get number of u32s to transfer */
count = saa7146_i2c_msg_prepare(msgs, num, buffer);
if ( 0 > count ) {
err = -1;
goto out;
}
if ( count > 3 || 0 != (SAA7146_I2C_SHORT_DELAY & dev->ext->flags) )
short_delay = 1;
do {
/* reset the i2c-device if necessary */
err = saa7146_i2c_reset(dev);
if ( 0 > err ) {
DEB_I2C("could not reset i2c-device\n");
goto out;
}
/* write out the u32s one after another */
for(i = 0; i < count; i++) {
err = saa7146_i2c_writeout(dev, &buffer[i], short_delay);
if ( 0 != err) {
/* this one is unsatisfying: some i2c slaves on some
dvb cards don't acknowledge correctly, so the saa7146
thinks that an address error occurred. in that case, the
transaction should be retrying, even if an address error
occurred. analog saa7146 based cards extensively rely on
i2c address probing, however, and address errors indicate that a
device is really *not* there. retrying in that case
increases the time the device needs to probe greatly, so
it should be avoided. So we bail out in irq mode after an
address error and trust the saa7146 address error detection. */
if (-EREMOTEIO == err && 0 != (SAA7146_USE_I2C_IRQ & dev->ext->flags))
goto out;
DEB_I2C("error while sending message(s). starting again\n");
break;
}
}
if( 0 == err ) {
err = num;
break;
}
/* delay a bit before retrying */
msleep(10);
} while (err != num && retries--);
/* quit if any error occurred */
if (err != num)
goto out;
/* if any things had to be read, get the results */
if ( 0 != saa7146_i2c_msg_cleanup(msgs, num, buffer)) {
DEB_I2C("could not cleanup i2c-message\n");
err = -1;
goto out;
}
/* return the number of delivered messages */
DEB_I2C("transmission successful. (msg:%d)\n", err);
out:
/* another bug in revision 0: the i2c-registers get uploaded randomly by other
uploads, so we better clear them out before continuing */
if( 0 == dev->revision ) {
__le32 zero = 0;
saa7146_i2c_reset(dev);
if( 0 != saa7146_i2c_writeout(dev, &zero, short_delay)) {
pr_info("revision 0 error. this should never happen\n");
}
}
mutex_unlock(&dev->i2c_lock);
return err;
}
/* utility functions */
static int saa7146_i2c_xfer(struct i2c_adapter* adapter, struct i2c_msg *msg, int num)
{
struct v4l2_device *v4l2_dev = i2c_get_adapdata(adapter);
struct saa7146_dev *dev = to_saa7146_dev(v4l2_dev);
/* use helper function to transfer data */
return saa7146_i2c_transfer(dev, msg, num, adapter->retries);
}
/*****************************************************************************/
/* i2c-adapter helper functions */
/* exported algorithm data */
static const struct i2c_algorithm saa7146_algo = {
.master_xfer = saa7146_i2c_xfer,
.functionality = saa7146_i2c_func,
};
int saa7146_i2c_adapter_prepare(struct saa7146_dev *dev, struct i2c_adapter *i2c_adapter, u32 bitrate)
{
DEB_EE("bitrate: 0x%08x\n", bitrate);
/* enable i2c-port pins */
saa7146_write(dev, MC1, (MASK_08 | MASK_24));
dev->i2c_bitrate = bitrate;
saa7146_i2c_reset(dev);
if (i2c_adapter) {
i2c_set_adapdata(i2c_adapter, &dev->v4l2_dev);
i2c_adapter->dev.parent = &dev->pci->dev;
i2c_adapter->algo = &saa7146_algo;
i2c_adapter->algo_data = NULL;
i2c_adapter->timeout = SAA7146_I2C_TIMEOUT;
i2c_adapter->retries = SAA7146_I2C_RETRIES;
}
return 0;
}
Reference in New Issue View Git Blame Copy Permalink