linux-stable.git/drivers/i2c, branch v4.4.136 Linux kernel stable tree i2c: rcar: revoke START request early 2018-06-06T14:46:22+00:00 Wolfram Sang wsa+renesas@sang-engineering.com 2015-11-19T15:56:49+00:00 ea37818a5410d44b9e269372b917960e0c4dc6ba commit 52df445f29b79006d8b2dcd129152987c0d3bd64 upstream. If we don't clear START generation as soon as possible, it may cause another message to be generated, e.g. when receiving NACK in address phase. To keep the race window as small as possible, we clear it right at the beginning of the interrupt. We don't need any checks since we always want to stop START and STOP generation on the next occasion after we started it. This patch improves the situation but sadly does not completely fix it. It is still to be researched if we can do better given this HW design. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com> Reviewed-by: Biju Das <biju.das@bp.renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 52df445f29b79006d8b2dcd129152987c0d3bd64 upstream.

If we don't clear START generation as soon as possible, it may cause
another message to be generated, e.g. when receiving NACK in address
phase. To keep the race window as small as possible, we clear it right
at the beginning of the interrupt. We don't need any checks since we
always want to stop START and STOP generation on the next occasion after
we started it.

This patch improves the situation but sadly does not completely fix it.
It is still to be researched if we can do better given this HW design.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Biju Das <biju.das@bp.renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
i2c: rcar: check master irqs before slave irqs 2018-06-06T14:46:22+00:00 Wolfram Sang wsa+renesas@sang-engineering.com 2015-11-19T15:56:48+00:00 fdcc1b764db0910ebd168a960247d409f0ce1340 commit c3be0af15959e11fa535d5332ab3d7cf34abd09b upstream. Due to the HW design, master IRQs are timing critical, so give them precedence over slave IRQ. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com> Reviewed-by: Biju Das <biju.das@bp.renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c3be0af15959e11fa535d5332ab3d7cf34abd09b upstream.

Due to the HW design, master IRQs are timing critical, so give them
precedence over slave IRQ.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Biju Das <biju.das@bp.renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
i2c: rcar: don't issue stop when HW does it automatically 2018-06-06T14:46:22+00:00 Wolfram Sang wsa+renesas@sang-engineering.com 2015-11-19T15:56:47+00:00 b414f20d848b786481a42a3c570cbfeedac61242 commit d89667b14f9d13b684287f6189ca209af5feee43 upstream. The manual says (55.4.8.6) that HW does automatically send STOP after NACK was received. My measuerments confirm that. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com> Reviewed-by: Biju Das <biju.das@bp.renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d89667b14f9d13b684287f6189ca209af5feee43 upstream.

The manual says (55.4.8.6) that HW does automatically send STOP after
NACK was received. My measuerments confirm that.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Biju Das <biju.das@bp.renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
i2c: rcar: init new messages in irq 2018-06-06T14:46:22+00:00 Wolfram Sang wsa+renesas@sang-engineering.com 2015-11-19T15:56:46+00:00 de427f7ee8255d1791e1b1c33e83a87035a778b4 commit cc21d0b4b62e41e5013d763adade5ea4462c33a4 upstream. Setting up new messages was done in process context while handling a message was in interrupt context. Because of the HW design, this IP core is sensitive to timing, so the context switches were too expensive. Move this setup to interrupt context as well. In my test setup, this fixed the occasional 'data byte sent twice' issue which a number of people have seen. It also fixes to send REP_START after a read message which was wrongly send as a STOP + START sequence before. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com> Reviewed-by: Chris Paterson <Chris.Paterson2@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit cc21d0b4b62e41e5013d763adade5ea4462c33a4 upstream.

Setting up new messages was done in process context while handling a
message was in interrupt context. Because of the HW design, this IP core
is sensitive to timing, so the context switches were too expensive. Move
this setup to interrupt context as well.

In my test setup, this fixed the occasional 'data byte sent twice' issue
which a number of people have seen. It also fixes to send REP_START
after a read message which was wrongly send as a STOP + START sequence
before.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Chris Paterson <Chris.Paterson2@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
i2c: rcar: refactor setup of a msg 2018-06-06T14:46:22+00:00 Wolfram Sang wsa+renesas@sang-engineering.com 2015-11-19T15:56:45+00:00 d088d20380b04e4dcc5f3531387c6df13da86e8b commit b9d0684c79c4b9d30ce0d47d3270493dd0e76e59 upstream. We want to reuse this function later. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com> Reviewed-by: Chris Paterson <Chris.Paterson2@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit b9d0684c79c4b9d30ce0d47d3270493dd0e76e59 upstream.

We want to reuse this function later.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Chris Paterson <Chris.Paterson2@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
i2c: rcar: remove spinlock 2018-06-06T14:46:22+00:00 Wolfram Sang wsa+renesas@sang-engineering.com 2015-11-19T15:56:44+00:00 bc6909d79f211823ded993786a23bca1737f9386 commit ff2316b87a336bff940939cd9fc56287ed48e578 upstream. After making sure to reinit the HW and clear interrupts in the timeout case, we know that interrupts are always disabled in the sections protected by the spinlock. Thus, we can simply remove it which is a preparation for further refactoring. While here, rename the timeout variable to time_left which is way more readable. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com> Reviewed-by: Chris Paterson <Chris.Paterson2@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit ff2316b87a336bff940939cd9fc56287ed48e578 upstream.

After making sure to reinit the HW and clear interrupts in the timeout
case, we know that interrupts are always disabled in the sections
protected by the spinlock. Thus, we can simply remove it which is a
preparation for further refactoring. While here, rename the timeout
variable to time_left which is way more readable.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Chris Paterson <Chris.Paterson2@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
i2c: rcar: remove unused IOERROR state 2018-06-06T14:46:22+00:00 Wolfram Sang wsa+renesas@sang-engineering.com 2015-11-19T15:56:43+00:00 90c9e4d18d785c3ae4ddd8df42a0cea5c3d05de2 commit 90f779e565bdc18dd4f79d81cf11f43a7266010b upstream. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com> Reviewed-by: Chris Paterson <Chris.Paterson2@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 90f779e565bdc18dd4f79d81cf11f43a7266010b upstream.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Chris Paterson <Chris.Paterson2@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
i2c: rcar: rework hw init 2018-06-06T14:46:22+00:00 Wolfram Sang wsa+renesas@sang-engineering.com 2015-11-19T15:56:42+00:00 7b72a3d26d990372a70280479b285f44e60337b6 commit 2c78cdc1c06308a59d6ed4145cdba73fdeff8c0d upstream. We don't need to init HW before every transfer since we know the HW state then. HW init at probe time is enough. While here, add setting the clock register which belongs to init HW. Also, set MDBS bit since not setting it is prohibited according to the manual. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com> Reviewed-by: Chris Paterson <Chris.Paterson2@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 2c78cdc1c06308a59d6ed4145cdba73fdeff8c0d upstream.

We don't need to init HW before every transfer since we know the HW
state then. HW init at probe time is enough. While here, add setting the
clock register which belongs to init HW. Also, set MDBS bit since not
setting it is prohibited according to the manual.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Chris Paterson <Chris.Paterson2@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
i2c: rcar: make sure clocks are on when doing clock calculation 2018-06-06T14:46:21+00:00 Wolfram Sang wsa+renesas@sang-engineering.com 2015-11-19T15:56:41+00:00 016b97b83c804796fb55316472f9b22f4cc92d05 commit e43e0df13f8528ca55ed79f469c4b2af897fa796 upstream. When calculating the bus speed, the clock should be on, of course. Most bootloaders left them on, so this went unnoticed so far. Move the ioremapping out of this clock-enabled-block and prepare for adding hw initialization there, too. Reported-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com> Reviewed-by: Chris Paterson <Chris.Paterson2@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit e43e0df13f8528ca55ed79f469c4b2af897fa796 upstream.

When calculating the bus speed, the clock should be on, of course. Most
bootloaders left them on, so this went unnoticed so far.

Move the ioremapping out of this clock-enabled-block and prepare for
adding hw initialization there, too.

Reported-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Chris Paterson <Chris.Paterson2@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
i2c: mv64xxx: Apply errata delay only in standard mode 2018-05-30T05:49:11+00:00 Gregory CLEMENT gregory.clement@bootlin.com 2018-03-14T17:03:40+00:00 82eac614c60e27d1014cc0c91b9bcc6b4cdc49db [ Upstream commit 31184d8c6ea49ea0676d100cdd7e1f102ad025b5 ] The errata FE-8471889 description has been updated. There is still a timing violation for repeated start. But the errata now states that it was only the case for the Standard mode (100 kHz), in Fast mode (400 kHz) there is no issue. This patch limit the errata fix to the Standard mode. It has been tesed successfully on the clearfog (Aramda 388 based board). Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 31184d8c6ea49ea0676d100cdd7e1f102ad025b5 ]

The errata FE-8471889 description has been updated. There is still a
timing violation for repeated start. But the errata now states that it
was only the case for the Standard mode (100 kHz), in Fast mode (400 kHz)
there is no issue.

This patch limit the errata fix to the Standard mode.

It has been tesed successfully on the clearfog (Aramda 388 based board).

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>