linux.git/drivers/i2c/busses, branch for-next

i2c: rcar: fix NACK handling when being a target

2025-01-15T18:37:33+00:00

When this controller is a target, the NACK handling had two issues.
First, the return value from the backend was not checked on the initial
WRITE_REQUESTED. So, the driver missed to send a NACK in this case.
Also, the NACK always arrives one byte late on the bus, even in the
WRITE_RECEIVED case. This seems to be a HW issue. We should then not
rely on the backend to correctly NACK the superfluous byte as well. Fix
both issues by introducing a flag which gets set whenever the backend
requests a NACK and keep sending it until we get a STOP condition.

Fixes: de20d1857dd6 ("i2c: rcar: add slave support")
Signed-off-by: Wolfram Sang

i2c: microchip-core: fix "ghost" detections

2024-12-26T00:54:47+00:00

Running i2c-detect currently produces an output akin to:
    0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:                         08 -- 0a -- 0c -- 0e --
10: 10 -- 12 -- 14 -- 16 -- UU 19 -- 1b -- 1d -- 1f
20: -- 21 -- 23 -- 25 -- 27 -- 29 -- 2b -- 2d -- 2f
30: -- -- -- -- -- -- -- -- 38 -- 3a -- 3c -- 3e --
40: 40 -- 42 -- 44 -- 46 -- 48 -- 4a -- 4c -- 4e --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: 60 -- 62 -- 64 -- 66 -- 68 -- 6a -- 6c -- 6e --
70: 70 -- 72 -- 74 -- 76 --

This happens because for an i2c_msg with a len of 0 the driver will
mark the transmission of the message as a success once the START has
been sent, without waiting for the devices on the bus to respond with an
ACK/NAK. Since i2cdetect seems to run in a tight loop over all addresses
the NAK is treated as part of the next test for the next address.

Delete the fast path that marks a message as complete when idev->msg_len
is zero after sending a START/RESTART since this isn't a valid scenario.

CC: stable@vger.kernel.org
Fixes: 64a6f1c4987e ("i2c: add support for microchip fpga i2c controllers")
Signed-off-by: Conor Dooley 
Reviewed-by: Andi Shyti 
Link: https://lore.kernel.org/r/20241218-outbid-encounter-b2e78b1cc707@spud
Signed-off-by: Andi Shyti

i2c: microchip-core: actually use repeated sends

2024-12-26T00:54:47+00:00

At present, where repeated sends are intended to be used, the
i2c-microchip-core driver sends a stop followed by a start. Lots of i2c
devices must not malfunction in the face of this behaviour, because the
driver has operated like this for years! Try to keep track of whether or
not a repeated send is required, and suppress sending a stop in these
cases.

CC: stable@vger.kernel.org
Fixes: 64a6f1c4987e ("i2c: add support for microchip fpga i2c controllers")
Signed-off-by: Conor Dooley 
Reviewed-by: Andi Shyti 
Link: https://lore.kernel.org/r/20241218-football-composure-e56df2461461@spud
Signed-off-by: Andi Shyti

i2c: imx: add imx7d compatible string for applying erratum ERR007805

2024-12-25T22:45:05+00:00

Compatible string "fsl,imx7d-i2c" is not exited at i2c-imx driver
compatible string table, at the result, "fsl,imx21-i2c" will be
matched, but it will cause erratum ERR007805 not be applied in fact.

So Add "fsl,imx7d-i2c" compatible string in i2c-imx driver to apply
the erratum ERR007805(https://www.nxp.com/docs/en/errata/IMX7DS_3N09P.pdf).

"
ERR007805 I2C: When the I2C clock speed is configured for 400 kHz,
the SCL low period violates the I2C spec of 1.3 uS min

Description: When the I2C module is programmed to operate at the
maximum clock speed of 400 kHz (as defined by the I2C spec), the SCL
clock low period violates the I2C spec of 1.3 uS min. The user must
reduce the clock speed to obtain the SCL low time to meet the 1.3us
I2C minimum required. This behavior means the SoC is not compliant
to the I2C spec at 400kHz.

Workaround: To meet the clock low period requirement in fast speed
mode, SCL must be configured to 384KHz or less.
"

"fsl,imx7d-i2c" already is documented in binding doc. This erratum
fix has been included in imx6_i2c_hwdata and it is the same in all
I.MX6/7/8, so just reuse it.

Fixes: 39c025721d70 ("i2c: imx: Implement errata ERR007805 or e7805 bus frequency limit")
Cc: stable@vger.kernel.org # v5.18+
Signed-off-by: Carlos Song 
Signed-off-by: Haibo Chen 
Reviewed-by: Frank Li 
Fixes: 39c025721d70 ("i2c: imx: Implement errata ERR007805 or e7805 bus frequency limit")
Acked-by: Oleksij Rempel 
Link: https://lore.kernel.org/r/20241218044238.143414-1-carlos.song@nxp.com
Signed-off-by: Andi Shyti

i2c: imx: fix missing stop condition in single-master mode

2024-12-25T22:45:04+00:00

A regression was introduced with the implementation of single-master
mode, preventing proper stop conditions from being generated. Devices
that require a valid stop condition, such as EEPROMs, fail to function
correctly as a result.

The issue only affects devices with the single-master property enabled.

This commit resolves the issue by re-enabling I2C bus busy bit (IBB)
polling for single-master mode when generating a stop condition. The fix
further ensures that the i2c_imx->stopped flag is cleared at the start
of each transfer, allowing the stop condition to be correctly generated
in i2c_imx_stop().

According to the reference manual (IMX8MMRM, Rev. 2, 09/2019, page
5270), polling the IBB bit to determine if the bus is free is only
necessary in multi-master mode. Consequently, the IBB bit is not polled
for the start condition in single-master mode.

Fixes: 6692694aca86 ("i2c: imx: do not poll for bus busy in single master mode")
Signed-off-by: Stefan Eichenberger 
Reviewed-by: Frank Li 
Reviewed-by: Francesco Dolcini 
Link: https://lore.kernel.org/r/20241216151829.74056-1-eichest@gmail.com
Signed-off-by: Andi Shyti

i2c: riic: Always round-up when calculating bus period

2024-12-12T11:54:02+00:00

Currently, the RIIC driver may run the I2C bus faster than requested,
which may cause subtle failures.  E.g. Biju reported a measured bus
speed of 450 kHz instead of the expected maximum of 400 kHz on RZ/G2L.

The initial calculation of the bus period uses DIV_ROUND_UP(), to make
sure the actual bus speed never becomes faster than the requested bus
speed.  However, the subsequent division-by-two steps do not use
round-up, which may lead to a too-small period, hence a too-fast and
possible out-of-spec bus speed.  E.g. on RZ/Five, requesting a bus speed
of 100 resp. 400 kHz will yield too-fast target bus speeds of 100806
resp. 403226 Hz instead of 97656 resp. 390625 Hz.

Fix this by using DIV_ROUND_UP() in the subsequent divisions, too.

Tested on RZ/A1H, RZ/A2M, and RZ/Five.

Fixes: d982d66514192cdb ("i2c: riic: remove clock and frequency restrictions")
Reported-by: Biju Das 
Signed-off-by: Geert Uytterhoeven 
Cc:  # v4.15+
Link: https://lore.kernel.org/r/c59aea77998dfea1b4456c4b33b55ab216fcbf5e.1732284746.git.geert+renesas@glider.be
Signed-off-by: Andi Shyti

i2c: nomadik: Add missing sentinel to match table

2024-12-10T15:07:53+00:00

The OF match table is not NULL-terminated.
Fix this by adding a sentinel to nmk_i2c_eyeq_match_table[].

Fixes: a0d15cc47f29be6d ("i2c: nomadik: switch from of_device_is_compatible() to of_match_device()")
Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Théo Lebrun 
Signed-off-by: Andi Shyti

i2c: pnx: Fix timeout in wait functions

2024-12-10T14:50:50+00:00

Since commit f63b94be6942 ("i2c: pnx: Fix potential deadlock warning
from del_timer_sync() call in isr") jiffies are stored in
i2c_pnx_algo_data.timeout, but wait_timeout and wait_reset are still
using it as milliseconds. Convert jiffies back to milliseconds to wait
for the expected amount of time.

Fixes: f63b94be6942 ("i2c: pnx: Fix potential deadlock warning from del_timer_sync() call in isr")
Signed-off-by: Vladimir Riabchun 
Signed-off-by: Andi Shyti

module: Convert default symbol namespace to string literal

2024-12-03T16:22:25+00:00

Commit cdd30ebb1b9f ("module: Convert symbol namespace to string
literal") only converted MODULE_IMPORT_NS() and EXPORT_SYMBOL_NS(),
leaving DEFAULT_SYMBOL_NAMESPACE as a macro expansion.

This commit converts DEFAULT_SYMBOL_NAMESPACE in the same way to avoid
annoyance for the default namespace as well.

Signed-off-by: Masahiro Yamada 
Reviewed-by: Uwe Kleine-König 
Signed-off-by: Linus Torvalds

module: Convert symbol namespace to string literal

2024-12-02T19:34:44+00:00

Clean up the existing export namespace code along the same lines of
commit 33def8498fdd ("treewide: Convert macro and uses of __section(foo)
to __section("foo")") and for the same reason, it is not desired for the
namespace argument to be a macro expansion itself.

Scripted using

  git grep -l -e MODULE_IMPORT_NS -e EXPORT_SYMBOL_NS | while read file;
  do
    awk -i inplace '
      /^#define EXPORT_SYMBOL_NS/ {
        gsub(/__stringify\(ns\)/, "ns");
        print;
        next;
      }
      /^#define MODULE_IMPORT_NS/ {
        gsub(/__stringify\(ns\)/, "ns");
        print;
        next;
      }
      /MODULE_IMPORT_NS/ {
        $0 = gensub(/MODULE_IMPORT_NS\(([^)]*)\)/, "MODULE_IMPORT_NS(\"\\1\")", "g");
      }
      /EXPORT_SYMBOL_NS/ {
        if ($0 ~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+),/) {
  	if ($0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)\)/ &&
  	    $0 !~ /(EXPORT_SYMBOL_NS[^(]*)\(\)/ &&
  	    $0 !~ /^my/) {
  	  getline line;
  	  gsub(/[[:space:]]*\\$/, "");
  	  gsub(/[[:space:]]/, "", line);
  	  $0 = $0 " " line;
  	}

  	$0 = gensub(/(EXPORT_SYMBOL_NS[^(]*)\(([^,]+), ([^)]+)\)/,
  		    "\\1(\\2, \"\\3\")", "g");
        }
      }
      { print }' $file;
  done

Requested-by: Masahiro Yamada 
Signed-off-by: Peter Zijlstra (Intel) 
Link: https://mail.google.com/mail/u/2/#inbox/FMfcgzQXKWgMmjdFwwdsfgxzKpVHWPlc
Acked-by: Greg KH 
Signed-off-by: Linus Torvalds