Geert Uytterhoeven reported that using devm_reset_controller_get leads
to a WARNING when probing a reset-controlled PHY. This is because the
device devm_reset_controller_get gets supplied is not actually the
one being probed.

Acquire an unmanaged reset-control as well as free the reset_control on
unregister to fix this.
Reported-by: NGeert Uytterhoeven <geert@linux-m68k.org>
CC: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid Bauer <mail@david-bauer.net>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 1d463956 ("mdio_bus: Fix PTR_ERR applied after initialization
to constant") accidentally changed a check from -ENOTSUPP to -ENOSYS,
causing failures if reset controller support is not enabled.  E.g. on
r7s72100/rskrza1:

    sh-eth e8203000.ethernet: MDIO init failed: -524
    sh-eth: probe of e8203000.ethernet failed with error -524

Seen on r8a7740/armadillo, r7s72100/rskrza1, and r7s9210/rza2mevb.

Fixes: 1d463956 ("mdio_bus: Fix PTR_ERR applied after initialization to constant")
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Cc: YueHaibing <yuehaibing@huawei.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 075e238d.

Going to go with Geert's fix instead, which also has a
correct Fixes tag.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 1d463956 ("mdio_bus: Fix PTR_ERR applied after initialization
to constant") accidentally changed a check from -ENOTSUPP to -ENOSYS,
causing failures if reset controller support is not enabled.  E.g. on
r7s72100/rskrza1:

    sh-eth e8203000.ethernet: MDIO init failed: -524
    sh-eth: probe of e8203000.ethernet failed with error -524

Seen on r8a7740/armadillo, r7s72100/rskrza1, and r7s9210/rza2mevb.

Fixes: 1d463956 ("mdio_bus: Fix PTR_ERR applied after initialization to constant")
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Cc: YueHaibing <yuehaibing@huawei.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When CONFIG_RESET_CONTROLLER is disabled, the
devm_reset_control_get_exclusive function returns -ENOTSUPP. This is not
handled in subsequent check and then the mdio device fails to probe.

When CONFIG_RESET_CONTROLLER is enabled, its code checks in OF for reset
device, and since it is not present, returns -ENOENT. -ENOENT is handled.
Add -ENOTSUPP also.

This happened to me when upgrading kernel on Turris Omnia. You either
have to enable CONFIG_RESET_CONTROLLER or use this patch.
Signed-off-by: NMarek Behún <marek.behun@nic.cz>
Fixes: 71dd6c0d ("net: phy: add support for reset-controller")
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix coccinelle warning:

./drivers/net/phy/mdio_bus.c:67:5-12: ERROR: PTR_ERR applied after initialization to constant on line 62
./drivers/net/phy/mdio_bus.c:68:5-12: ERROR: PTR_ERR applied after initialization to constant on line 62

Fix this by using IS_ERR before PTR_ERR
Reported-by: NHulk Robot <hulkci@huawei.com>
Fixes: 71dd6c0d ("net: phy: add support for reset-controller")
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The MDIO device reset line is optional and now that gpiod_get_optional()
returns proper value when GPIO support is compiled out, there is no
reason to use fwnode_get_named_gpiod() that I plan to hide away.

Let's switch to using more standard gpiod_get_optional() and
gpiod_set_consumer_name() to keep the nice "PHY reset" label.

Also there is no reason to only try to fetch the reset GPIO when we have
OF node, gpiolib can fetch GPIO data from firmwares as well.
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce wrappers for {bus/driver/class}_find_device() to
locate devices by its of_node.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <maxime.ripard@bootlin.com>
Cc: dri-devel@lists.freedesktop.org
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: devicetree@vger.kernel.org
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: linux-i2c@vger.kernel.org
Cc: linux-rockchip@lists.infradead.org
Cc: linux-spi@vger.kernel.org
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Alan Tull <atull@kernel.org>
Cc: linux-fpga@vger.kernel.org
Cc: Peter Rosin <peda@axentia.se>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Thor Thayer <thor.thayer@linux.intel.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Peter Rosin <peda@axentia.se>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: NLee Jones <lee.jones@linaro.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de> # I2C part
Acked-by: Moritz Fischer <mdf@kernel.org> # For FPGA part
Acked-by: NMark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20190723221838.12024-3-suzuki.poulose@arm.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This renames the GPIO reset of mdio devices from 'reset' to
'reset_gpio' to better differentiate between GPIO and
reset-controller driven reset line.
Signed-off-by: NDavid Bauer <mail@david-bauer.net>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This commit adds support for PHY reset pins handled by a reset controller.
Signed-off-by: NDavid Bauer <mail@david-bauer.net>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

KASAN has found use-after-free in fixed_mdio_bus_init,
commit 0c692d07 ("drivers/net/phy/mdio_bus.c: call
put_device on device_register() failure") call put_device()
while device_register() fails,give up the last reference
to the device and allow mdiobus_release to be executed
,kfreeing the bus. However in most drives, mdiobus_free
be called to free the bus while mdiobus_register fails.
use-after-free occurs when access bus again, this patch
revert it to let mdiobus_free free the bus.

KASAN report details as below:

BUG: KASAN: use-after-free in mdiobus_free+0x85/0x90 drivers/net/phy/mdio_bus.c:482
Read of size 4 at addr ffff8881dc824d78 by task syz-executor.0/3524

CPU: 1 PID: 3524 Comm: syz-executor.0 Not tainted 5.0.0-rc7+ #45
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xfa/0x1ce lib/dump_stack.c:113
 print_address_description+0x65/0x270 mm/kasan/report.c:187
 kasan_report+0x149/0x18d mm/kasan/report.c:317
 mdiobus_free+0x85/0x90 drivers/net/phy/mdio_bus.c:482
 fixed_mdio_bus_init+0x283/0x1000 [fixed_phy]
 ? 0xffffffffc0e40000
 ? 0xffffffffc0e40000
 ? 0xffffffffc0e40000
 do_one_initcall+0xfa/0x5ca init/main.c:887
 do_init_module+0x204/0x5f6 kernel/module.c:3460
 load_module+0x66b2/0x8570 kernel/module.c:3808
 __do_sys_finit_module+0x238/0x2a0 kernel/module.c:3902
 do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x462e99
Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6215c19c58 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
RAX: ffffffffffffffda RBX: 000000000073bf00 RCX: 0000000000462e99
RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000003
RBP: 00007f6215c19c70 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6215c1a6bc
R13: 00000000004bcefb R14: 00000000006f7030 R15: 0000000000000004

Allocated by task 3524:
 set_track mm/kasan/common.c:85 [inline]
 __kasan_kmalloc.constprop.3+0xa0/0xd0 mm/kasan/common.c:496
 kmalloc include/linux/slab.h:545 [inline]
 kzalloc include/linux/slab.h:740 [inline]
 mdiobus_alloc_size+0x54/0x1b0 drivers/net/phy/mdio_bus.c:143
 fixed_mdio_bus_init+0x163/0x1000 [fixed_phy]
 do_one_initcall+0xfa/0x5ca init/main.c:887
 do_init_module+0x204/0x5f6 kernel/module.c:3460
 load_module+0x66b2/0x8570 kernel/module.c:3808
 __do_sys_finit_module+0x238/0x2a0 kernel/module.c:3902
 do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 3524:
 set_track mm/kasan/common.c:85 [inline]
 __kasan_slab_free+0x130/0x180 mm/kasan/common.c:458
 slab_free_hook mm/slub.c:1409 [inline]
 slab_free_freelist_hook mm/slub.c:1436 [inline]
 slab_free mm/slub.c:2986 [inline]
 kfree+0xe1/0x270 mm/slub.c:3938
 device_release+0x78/0x200 drivers/base/core.c:919
 kobject_cleanup lib/kobject.c:662 [inline]
 kobject_release lib/kobject.c:691 [inline]
 kref_put include/linux/kref.h:67 [inline]
 kobject_put+0x146/0x240 lib/kobject.c:708
 put_device+0x1c/0x30 drivers/base/core.c:2060
 __mdiobus_register+0x483/0x560 drivers/net/phy/mdio_bus.c:382
 fixed_mdio_bus_init+0x26b/0x1000 [fixed_phy]
 do_one_initcall+0xfa/0x5ca init/main.c:887
 do_init_module+0x204/0x5f6 kernel/module.c:3460
 load_module+0x66b2/0x8570 kernel/module.c:3808
 __do_sys_finit_module+0x238/0x2a0 kernel/module.c:3902
 do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8881dc824c80
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 248 bytes inside of
 2048-byte region [ffff8881dc824c80, ffff8881dc825480)
The buggy address belongs to the page:
page:ffffea0007720800 count:1 mapcount:0 mapping:ffff8881f6c02800 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000010200(slab|head)
raw: 02fffc0000010200 0000000000000000 0000000500000001 ffff8881f6c02800
raw: 0000000000000000 00000000800f000f 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881dc824c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881dc824c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881dc824d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                                ^
 ffff8881dc824d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881dc824e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

Fixes: 0c692d07 ("drivers/net/phy/mdio_bus.c: call put_device on device_register() failure")
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix coccinelle warning:

./drivers/net/phy/mdio_bus.c:51:5-12: ERROR: PTR_ERR applied after initialization to constant on line 44
./drivers/net/phy/mdio_bus.c:52:5-12: ERROR: PTR_ERR applied after initialization to constant on line 44

fix this by using IS_ERR before PTR_ERR

Fixes: bafbdd52 ("phylib: Add device reset GPIO support")
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Where the license text and the MODULE_LICENSE() value agree, convert
to using an SPDX header, removing the license text.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The current code in __mdiobus_register() doesn't properly handle
failures returned by the devm_gpiod_get_optional() call: it returns
immediately, without unregistering the device that was added by the
call to device_register() earlier in the function.

This leaves a stale device, which then causes a NULL pointer
dereference in the code that handles deferred probing:

[    1.489982] Unable to handle kernel NULL pointer dereference at virtual address 00000074
[    1.498110] pgd = (ptrval)
[    1.500838] [00000074] *pgd=00000000
[    1.504432] Internal error: Oops: 17 [#1] SMP ARM
[    1.509133] Modules linked in:
[    1.512192] CPU: 1 PID: 51 Comm: kworker/1:3 Not tainted 4.20.0-00039-g3b73a4cc8b3e-dirty #99
[    1.520708] Hardware name: Xilinx Zynq Platform
[    1.525261] Workqueue: events deferred_probe_work_func
[    1.530403] PC is at klist_next+0x10/0xfc
[    1.534403] LR is at device_for_each_child+0x40/0x94
[    1.539361] pc : [<c0683fbc>]    lr : [<c0455d90>]    psr: 200e0013
[    1.545628] sp : ceeefe68  ip : 00000001  fp : ffffe000
[    1.550863] r10: 00000000  r9 : c0c66790  r8 : 00000000
[    1.556079] r7 : c0457d44  r6 : 00000000  r5 : ceeefe8c  r4 : cfa2ec78
[    1.562604] r3 : 00000064  r2 : c0457d44  r1 : ceeefe8c  r0 : 00000064
[    1.569129] Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
[    1.576263] Control: 18c5387d  Table: 0ed7804a  DAC: 00000051
[    1.582013] Process kworker/1:3 (pid: 51, stack limit = 0x(ptrval))
[    1.588280] Stack: (0xceeefe68 to 0xceef0000)
[    1.592630] fe60:                   cfa2ec78 c0c03c08 00000000 c0457d44 00000000 c0c66790
[    1.600814] fe80: 00000000 c0455d90 ceeefeac 00000064 00000000 0d7a542e cee9d494 cfa2ec78
[    1.608998] fea0: cfa2ec78 00000000 c0457d44 c0457d7c cee9d494 c0c03c08 00000000 c0455dac
[    1.617182] fec0: cf98ba44 cf926a00 cee9d494 0d7a542e 00000000 cf935a10 cf935a10 cf935a10
[    1.625366] fee0: c0c4e9b8 c0457d7c c0c4e80c 00000001 cf935a10 c0457df4 cf935a10 c0c4e99c
[    1.633550] ff00: c0c4e99c c045a27c c0c4e9c4 ced63f80 cfde8a80 cfdebc00 00000000 c013893c
[    1.641734] ff20: cfde8a80 cfde8a80 c07bd354 ced63f80 ced63f94 cfde8a80 00000008 c0c02d00
[    1.649936] ff40: cfde8a98 cfde8a80 ffffe000 c0139a30 ffffe000 c0c6624a c07bd354 00000000
[    1.658120] ff60: ffffe000 cee9e780 ceebfe00 00000000 ceeee000 ced63f80 c0139788 cf8cdea4
[    1.666304] ff80: cee9e79c c013e598 00000001 ceebfe00 c013e44c 00000000 00000000 00000000
[    1.674488] ffa0: 00000000 00000000 00000000 c01010e8 00000000 00000000 00000000 00000000
[    1.682671] ffc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[    1.690855] ffe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000
[    1.699058] [<c0683fbc>] (klist_next) from [<c0455d90>] (device_for_each_child+0x40/0x94)
[    1.707241] [<c0455d90>] (device_for_each_child) from [<c0457d7c>] (device_reorder_to_tail+0x38/0x88)
[    1.716476] [<c0457d7c>] (device_reorder_to_tail) from [<c0455dac>] (device_for_each_child+0x5c/0x94)
[    1.725692] [<c0455dac>] (device_for_each_child) from [<c0457d7c>] (device_reorder_to_tail+0x38/0x88)
[    1.734927] [<c0457d7c>] (device_reorder_to_tail) from [<c0457df4>] (device_pm_move_to_tail+0x28/0x40)
[    1.744235] [<c0457df4>] (device_pm_move_to_tail) from [<c045a27c>] (deferred_probe_work_func+0x58/0x8c)
[    1.753746] [<c045a27c>] (deferred_probe_work_func) from [<c013893c>] (process_one_work+0x210/0x4fc)
[    1.762888] [<c013893c>] (process_one_work) from [<c0139a30>] (worker_thread+0x2a8/0x5c0)
[    1.771072] [<c0139a30>] (worker_thread) from [<c013e598>] (kthread+0x14c/0x154)
[    1.778482] [<c013e598>] (kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c)
[    1.785689] Exception stack(0xceeeffb0 to 0xceeefff8)
[    1.790739] ffa0:                                     00000000 00000000 00000000 00000000
[    1.798923] ffc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
[    1.807107] ffe0: 00000000 00000000 00000000 00000000 00000013 00000000
[    1.813724] Code: e92d47f0 e1a05000 e8900048 e1a00003 (e5937010)
[    1.819844] ---[ end trace 3c2c0c8b65399ec9 ]---

The actual error that we had from devm_gpiod_get_optional() was
-EPROBE_DEFER, due to the GPIO being provided by a driver that is
probed later than the Ethernet controller driver.

To fix this, we simply add the missing device_del() invocation in the
error path.

Fixes: 69226896 ("mdio_bus: Issue GPIO RESET to PHYs")
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@bootlin.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There's no need to and one shouldn't include asm/irq.h directly.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove duplicated include linux/gpio/consumer.h
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Current implementation of MDIO bus PM ops doesn't actually implement
bus-specific PM ops but just calls PM ops defined on a device level
what doesn't seem to be fully in line with the core PM model.

When looking e.g. at __device_suspend() the PM core looks for PM ops
of a device in a specific order:
1. device PM domain
2. device type
3. device class
4. device bus

I think it has good reason that there's no PM ops on device level.

Now that a device type representation of PHY's as special type of MDIO
devices was added (only user of MDIO bus PM ops), the MDIO bus
PM ops can be removed including member pm of struct mdio_device.

If for some other type of MDIO device PM ops are needed, it should be
modeled as struct device_type as well.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If CONFIG_GPIOLIB is disabled, fwnode_get_named_gpiod() becomes a stub
function, which return -ENOSYS. Handle this in the same way as
-ENOENT, i.e. assume there is no GPIO used to reset the PHYs.
Reported-by: NChristian Zigotzky <chzigotzky@xenosoft.de>
Tested-by: NChristian Zigotzky <chzigotzky@xenosoft.de>
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Fixes: bafbdd52 ("phylib: Add device reset GPIO support")
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Ethernet switch on the MDIO bus have historically performed their own
handling of the GPIO reset line. The resent patch to have the MDIO
core handle the reset has broken the switch drivers, in that they
cannot claim the GPIO. Some switch drivers need more control over the
GPIO line than what the MDIO core provides. So restore the historical
behaviour by only performing a reset of PHYs, not switches.

Fixes: bafbdd52 ("phylib: Add device reset GPIO support")
Reported-by: NSean Wang <sean.wang@mediatek.com>
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Tested-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add unlocked versions of the bus accessors, which allows access to the
bus with all the tracing. These accessors validate that the bus mutex
is held, which is a basic requirement for all mii bus accesses.
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Ensure that all mdio devices populate the struct device fwnode pointer
as well as the of_node pointer to allow drivers that wish to use
fwnode APIs to work.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: NRob Herring <robh@kernel.org>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The PHY devices sometimes do have their reset signal (maybe even power
supply?) tied to some GPIO and sometimes it also does happen that a boot
loader does not leave it deasserted. So far this issue has been attacked
from (as I believe) a wrong angle: by teaching the MAC driver to manipulate
the GPIO in question; that solution, when applied to the device trees, led
to adding the PHY reset GPIO properties to the MAC device node, with one
exception: Cadence MACB driver which could handle the "reset-gpios" prop
in a PHY device subnode. I believe that the correct approach is to teach
the 'phylib' to get the MDIO device reset GPIO from the device tree node
corresponding to this device -- which this patch is doing...

Note that I had to modify the AT803x PHY driver as it would stop working
otherwise -- it made use of the reset GPIO for its own purposes...
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Acked-by: NRob Herring <robh@kernel.org>
[geert: Propagate actual errors from fwnode_get_named_gpiod()]
[geert: Avoid destroying initial setup]
[geert: Consolidate GPIO descriptor acquiring code]
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Tested-by: NRichard Leitner <richard.leitner@skidata.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 95b80bf3 ("mdio_bus:
Remove unneeded gpiod NULL check"), this commit assumed that GPIOLIB
checks for NULL descriptors, so it's safe to drop them, but it is not
when CONFIG_GPIOLIB is disabled in the kernel. If we do call
gpiod_set_value_cansleep() on a GPIO descriptor we will issue warnings
coming from the inline stubs declared in include/linux/gpio/consumer.h.

Fixes: 95b80bf3 ("mdio_bus: Remove unneeded gpiod NULL check")
Reported-by: NWoojung Huh <Woojung.Huh@microchip.com>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The gpiod API checks for NULL descriptors, so there is no need to
duplicate the check in the driver.
Signed-off-by: NFabio Estevam <fabio.estevam@nxp.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The MDIO reset GPIO is really a classical optional GPIO property case,
so devm_gpiod_get_optional() should have been used, not devm_gpiod_get().
Doing this  saves several LoCs...
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 4c5e7a2c ("dt-bindings: mdio: Clarify binding document")
declared that a MDIO reset GPIO property should have only a single GPIO
reference/specifier, however the supporting code was left intact, still
burdening the kernel with now apparently useless loops -- get rid of them.
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

use of_mdio_parse_addr() in place of an OF read of reg and a bounds
check (which is litterally the exact same thing that
of_mdio_parse_addr() does)
Signed-off-by: NJon Mason <jon.mason@broadcom.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Auto-loading of the Marvell DSA driver has stopped working with recent
kernels.  This seems to be due to the change of binding for DSA devices,
moving them from the platform bus to the MDIO bus.

In order for module auto-loading to work, we need to provide a MODALIAS
string in the uevent file for the device.  However, the device core does
not automatically provide this, and needs each bus_type to implement a
uevent method to generate these strings.  The MDIO bus does not provide
such a method, so no MODALIAS string is provided:

.# cat /sys/bus/mdio_bus/devices/f1072004.mdio-mii\:04/uevent
DRIVER=mv88e6085
OF_NAME=switch
OF_FULLNAME=/soc/internal-regs/mdio@72004/switch@4
OF_COMPATIBLE_0=marvell,mv88e6085
OF_COMPATIBLE_N=1

In the case of OF-based devices, the solution is easy -
of_device_uevent_modalias() does the work for us.  After this is done,
the uevent file looks like this:

.# cat /sys/bus/mdio_bus/devices/f1072004.mdio-mii\:04/uevent
DRIVER=mv88e6085
OF_NAME=switch
OF_FULLNAME=/soc/internal-regs/mdio@72004/switch@4
OF_COMPATIBLE_0=marvell,mv88e6085
OF_COMPATIBLE_N=1
MODALIAS=of:NswitchT<NULL>Cmarvell,mv88e6085

which results in auto-loading of the Marvell DSA driver on Clearfog
platforms.

Fixes: c0405563 ("ARM: dts: armada-388-clearfog: Utilize new DSA binding")
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The API convention makes it that a given MDIO bus reset should be able
to access PHY devices in its reset() callback and perform additional
MDIO accesses in order to bring the bus and PHYs in a working state.

Commit 69226896 ("mdio_bus: Issue GPIO RESET to PHYs.") broke that
contract by first calling bus->reset() and then release all PHYs from
reset using their shared GPIO line, so restore the expected
functionality here.

Fixes: 69226896 ("mdio_bus: Issue GPIO RESET to PHYs.")
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some boards [1] leave the PHYs at an invalid state
during system power-up or reset thus causing unreliability
issues with the PHY which manifests as PHY not being detected
or link not functional. To fix this, these PHYs need to be RESET
via a GPIO connected to the PHY's RESET pin.

Some boards have a single GPIO controlling the PHY RESET pin of all
PHYs on the bus whereas some others have separate GPIOs controlling
individual PHY RESETs.

In both cases, the RESET de-assertion cannot be done in the PHY driver
as the PHY will not probe till its reset is de-asserted.
So do the RESET de-assertion in the MDIO bus driver.

[1] - am572x-idk, am571x-idk, a437x-idk
Signed-off-by: NRoger Quadros <rogerq@ti.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

mdio-boardinfo contains code that is helpful for platforms to register
specific MDIO bus devices independent of how CONFIG_MDIO_DEVICE or
CONFIG_PHYLIB will be selected (modular or built-in). In order to make
that possible, let's do the following:

- descend into drivers/net/phy/ unconditionally

- make mdiobus_setup_mdiodev_from_board_info() take a callback argument
  which allows us not to expose the internal MDIO board info list and
  mutex, yet maintain the logic within the same file

- relocate the code that creates a MDIO device into
  drivers/net/phy/mdio_bus.c

- build mdio-boardinfo.o into the kernel as soon as MDIO_DEVICE is
  defined (y or m)

Fixes: 90eff909 ("net: phy: Allow splitting MDIO bus/device support from PHYs")
Fixes: 648ea013 ("net: phy: Allow pre-declaration of MDIO devices")
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Tested-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce a new configuration symbol: MDIO_DEVICE which allows building
the MDIO devices and bus code, without pulling in the entire Ethernet
PHY library and devices code.

PHYLIB nows select MDIO_DEVICE and the relevant Makefile files are
updated to reflect that.

When MDIO_DEVICE (MDIO bus/device only) is selected, but not PHYLIB, we
have mdio-bus.ko as a loadable module, and it does not have a
module_exit() function because the safety of removing a bus class is
unclear.

When both MDIO_DEVICE and PHYLIB are enabled, we need to assemble
everything into a common loadable module: libphy.ko because of nasty
circular dependencies between phy.c, phy_device.c and mdio_bus.c which
are really tough to untangle.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allow board support code to collect pre-declarations for MDIO devices by
registering them with mdiobus_register_board_info(). SPI and I2C buses
have a similar feature, we were missing this for MDIO devices, but this
is particularly useful for e.g: MDIO-connected switches which need to
provide their port layout (often board-specific) to a MDIO Ethernet
switch driver.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make it possible to generate trace events for mdio read and write accesses.
Signed-off-by: NUwe Kleine-König <uwe@kleine-koenig.org>
Acked-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I've finally noticed that mdiobus_scan() also returns either NULL or error
value on failure.  Return ERR_PTR(-ENODEV) instead of NULL since this is
the  error value  already filtered out by the callers that want to ignore
the  MDIO address scan failure...
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since commit b74766a0 ("phylib: don't return NULL
from get_phy_device()") in linux-next, phy_get_device() will return
ERR_PTR(-ENODEV) instead of NULL if the PHY device ID is all ones.

This causes problem with stmmac driver and likely some other drivers
which call mdiobus_register(). I triggered this bug on SoCFPGA MCVEVK
board with linux-next 20160427 and 20160428. In case of the stmmac, if
there is no PHY node specified in the DT for the stmmac block, the stmmac
driver ( drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c function
stmmac_mdio_register() ) will call mdiobus_register() , which will
register the MDIO bus and probe for the PHY.

The mdiobus_register() resp. __mdiobus_register() iterates over all of
the addresses on the MDIO bus and calls mdiobus_scan() for each of them,
which invokes get_phy_device(). Before the aforementioned patch, the
mdiobus_scan() would return NULL if no PHY was found on a given address
and mdiobus_register() would continue and try the next PHY address. Now,
mdiobus_scan() returns ERR_PTR(-ENODEV), which is caught by the
'if (IS_ERR(phydev))' condition and the loop exits immediately if the
PHY address does not contain PHY.

Repair this by explicitly checking for the ERR_PTR(-ENODEV) and if this
error comes around, continue with the next PHY address.
Signed-off-by: NMarek Vasut <marex@denx.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@opensource.altera.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that get_phy_device() no longer returns NULL on error, we don't need
to check for it...
Signed-off-by: NSergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

MDIO devices can be stacked upon each other. The current code supports
two levels, which until recently has been enough for a DSA mdio bus on
top of another bus. Now we have hardware which has an MDIO mux in the
middle.

Define an MDIO MUTEX class with three levels.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If bus = kzalloc() fails then we end up dereferencing bus when we do
"bus->irq[i] = PHY_POLL;".  The code is a little simpler if we reverse
the NULL check and return directly on failure.

Fixes: e7f4dc35 ('mdio: Move allocation of interrupts into core')
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make device_free and device_remove operations in the mdio device
structure, so the core code does not need to differentiate between
phy devices and generic mdio devices.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>