Add ethtool operation to read RMON registers.

Tested against net-next on i.MX28.

v2: make conditional on #ifndef CONFIG_M5272
Signed-off-by: NChris Healy <cphealy@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add ethtool operation to restart autonegotiation via the PHY.

Tested on i.MX28EVK.
Signed-off-by: NChris Healy <cphealy@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 75096579 ("lib: devres: Introduce devm_ioremap_resource()")
introduced devm_ioremap_resource() and deprecated the use of
devm_request_and_ioremap().
Signed-off-by: NTushar Behera <tushar.behera@linaro.org>
CC: netdev@vger.kernel.org
CC: "David S. Miller" <davem@davemloft.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Passing pdev in fec_ptp_init() is enough, since we can get ndev locally.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If no valid MAC address could be obtained from the hardware,
fall back to a randomly generated one.
Signed-off-by: NPavel Machek <pavel@denx.de>
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver core clears the driver data to NULL after device_release
or on probe failure, since commit 0998d063
(device-core: Ensure drvdata = NULL when no driver is bound).
Thus, it is not needed to manually clear the device driver data to NULL.
Signed-off-by: NJingoo Han <jg1.han@samsung.com>
Acked-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: NRob Herring <rob.herring@calxeda.com>
Acked-by: NRoland Stigge <stigge@antcom.de>
Acked-by: NMugunthan V N <mugunthanvnm@ti.com>
Reviewed-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Tested-by: NRoland Stigge <stigge@antcom.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to save power, let's disable the regulator in the suspend function and
enable it in resume.

Tested on a mx28evk board.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

During probe the clocks are enabled prior than the acquiring the interrupts.

In the remove function we need to do the opposite: first remove the interrupts
and then disable the clocks.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In the case of error during probe, disable the PHY regulator.

Do the same in fec_drv_remove().
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently when fec_enet_init fails it jumps to 'failed_init' error path, which
will attemp to free the interrupts.

This is wrong because at this point the interrupts have not even been acquired.

Swap failed_init/failed_irq to fix the error path.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of using a local reg_phy structure, let's put it inside the private
structure, so that we are able to have access to the regulator structure even
when we are outside fec_probe().

This is in preparation for controlling the FEC PHY regulator in the suspend and
resume functions.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use the standard DIV_ROUND_UP macro in order to provide better readability.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

MVF is a family while MVF600 is a particular SoC in the family.  We
generally prefer to use SoC rather than family name in compatible string
to define a particular type of fec device.  And this is how fec_dt_ids
works for all those IMX fec variants.  Let's change mvf to mvf600 to
have it work in the same way.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since commit ab78029e (drivers/pinctrl: grab default handles from device core)
we can rely on device core for handling pinctrl, so remove
devm_pinctrl_get_select_default() from the driver.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit 54309fa6 ("net: fec: fix kernel oops when plug/unplug cable many times")
introduced the following 'if' block in the beginning of fec_start():

	if (netif_running(ndev)) {
		netif_device_detach(ndev);
		napi_disable(&fep->napi);
		netif_stop_queue(ndev);
		netif_tx_lock_bh(ndev);
	}

Then later in the end of fec_restart() there is another block that calls the
opposite of each one of these functions.

The correct approach would be to also call them with in the reverse order, so
that we have as result:

	if (netif_running(ndev)) {
		netif_tx_unlock_bh(ndev);
		netif_wake_queue(ndev);
		napi_enable(&fep->napi);
		netif_device_attach(ndev);
	}
Suggested-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

fec_restart() runs in softirq context and we should use the
netif_tx_lock_bh/netif_tx_unlock_bh() variants to avoid the following warning
that happens since commit 54309fa6 ("net: fec: fix kernel oops when plug/unplug
cable many times"):

[    9.753168] =================================
[    9.757540] [ INFO: inconsistent lock state ]
[    9.761921] 3.10.0-rc1-next-20130514 #13 Not tainted
[    9.766897] ---------------------------------
[    9.771264] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
[    9.777288] swapper/0 [HC0[0]:SC1[3]:HE1:SE0] takes:
[    9.782261]  (_xmit_ETHER#2){+.?...}, at: [<c03c24a4>] sch_direct_xmit+0xa0/0x2d4
[    9.789879] {SOFTIRQ-ON-W} state was registered at:
[    9.794769]   [<c0059c60>] __lock_acquire+0x528/0x1bc0
[    9.799953]   [<c005b838>] lock_acquire+0xa0/0x108
[    9.804780]   [<c0441320>] _raw_spin_lock+0x28/0x38
[    9.809702]   [<c02f9fc8>] fec_restart+0x5d0/0x664
[    9.814542]   [<c02fa738>] fec_enet_adjust_link+0xa8/0xc0
[    9.819978]   [<c02f7a28>] phy_state_machine+0x2fc/0x370
[    9.825323]   [<c0035ee0>] process_one_work+0x1c0/0x4a0
[    9.830589]   [<c0036594>] worker_thread+0x138/0x394
[    9.835587]   [<c003c620>] kthread+0xa4/0xb0
[    9.839890]   [<c000e820>] ret_from_fork+0x14/0x34
[    9.844728] irq event stamp: 185984
[    9.848226] hardirqs last  enabled at (185984): [<c00232b0>] local_bh_enable_ip+0x84/0xf0
[    9.856450] hardirqs last disabled at (185983): [<c0023270>] local_bh_enable_ip+0x44/0xf0
[    9.864667] softirqs last  enabled at (185966): [<c0023470>] irq_enter+0x64/0x68
[    9.872099] softirqs last disabled at (185967): [<c0023510>] irq_exit+0x9c/0xd8
[    9.879440]
[    9.879440] other info that might help us debug this:
[    9.885981]  Possible unsafe locking scenario:
[    9.885981]
[    9.891912]        CPU0
[    9.894364]        ----
[    9.896814]   lock(_xmit_ETHER#2);
[    9.900259]   <Interrupt>
[    9.902884]     lock(_xmit_ETHER#2);
[    9.906500]
[    9.906500]  *** DEADLOCK ***
Reported-by: NShawn Guo <shawn.guo@linaro.org>
Suggested-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 4c09eed9 (net: fec: Enable imx6 enet checksum acceleration.)
enables hardware checksum acceleration unconditionally for all fec
variants.  This is inappropriate, because some variants like imx5 have
no such support on hardware.  Consequently, fec is broken on these
platforms.  Fix it by enabling hardware checksum only on imx6q-fec type
of controllers.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Reviewed-by: NJim Baxter <jim_baxter@mentor.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

reproduce steps
 1. flood ping from other machine
 	ping -f -s 41000 IP
 2. run below script
    while [ 1 ]; do ethtool -s eth0 autoneg off;
    sleep 3;ethtool -s eth0 autoneg on; sleep 4; done;

You can see oops in one hour.

The reason is fec_restart clear BD but NAPI may use it.
The solution is disable NAPI and stop xmit when reset BD.
disable NAPI may sleep, so fec_restart can't be call in
atomic context.
Signed-off-by: NFrank Li <Frank.Li@freescale.com>
Reviewed-by: NLucas Stach <l.stach@pengutronix.de>
Tested-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Enables hardware generation of IP header and
protocol specific checksums for transmitted
packets.

Enabled hardware discarding of received packets with
invalid IP header or protocol specific checksums.

The feature is enabled by default but can be
enabled/disabled by ethtool.
Signed-off-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NJim Baxter <jim_baxter@mentor.com>
Reviewed-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is nothing in the driver that requires <asm/coldfire.h> and
<asm/mcfsim.h>.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Using SIMPLE_DEV_PM_OPS can make the code smaller and simpler.

Also change CONFIG_PM to CONFIG_PM_SLEEP.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use a more current logging message style.

Convert the printks where a struct net_device is available to
netdev_<level>.  Convert the other printks to pr_<level> and
add pr_fmt where appropriate.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently when booting a mx6 device we get the following on boot:

registered PHC device on eth%d

Fix it by printing the network device name only after it gets registered, so
that the following can be read now:

fec 2188000.ethernet eth0: registered PHC device 0
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Freescale Vybrid platform implentments MAC-ENET core
providing compatibility with half- or full-duplex
10/100 Mbit/s Ethernet LANs.
Signed-off-by: NJingchang Lu <b35083@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since of_get_mac_address() is now defined even if CONFIG_OF_NET
is not configured, the ifdef around the code calling it is no longer
necessary and can be removed.

Similar, since of_get_phy_mode() is now defined as dummy function
if OF_NET is not configured, it is no longer necessary to provide
an OF dependent function as front-end. Also, the function depends
on OF_NET, not on OF, so the conditional code was not correct anyway.
Drop the front-end function and call of_get_phy_mode() directly.
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The TX Buffer in fec_enet_alloc_buffers was being initialized
with the receive register define BD_ENET_RX_INT instead of
the transmit register define BD_ENET_TX_INT
Signed-off-by: NJim Baxter <jim_baxter@mentor.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

fec_ptp.ko can't run individually
rename fec.c to fec_main.c
Build fec.o and fec_ptp.o into one fec.ko
Remove unnessary EXPORT_SYMBOL in fec_ptp
Signed-off-by: NFrank Li <Frank.Li@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

fec_poll_controller() was not declared. It should be static.
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix the following warnings that happen when building with W=1 option:

drivers/net/ethernet/freescale/fec.c: In function 'fec_enet_free_buffers':
drivers/net/ethernet/freescale/fec.c:1337:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
drivers/net/ethernet/freescale/fec.c: In function 'fec_enet_alloc_buffers':
drivers/net/ethernet/freescale/fec.c:1361:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
drivers/net/ethernet/freescale/fec.c: In function 'fec_enet_init':
drivers/net/ethernet/freescale/fec.c:1631:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

I believe these error messages are already logged
on allocation failure by warn_alloc_failed and so
get a dump_stack on OOM.

Remove the unnecessary additional error logging.

Around these deletions:

o Alignment neatening.
o Remove unnecessary casts of dma_alloc_coherent.
o Hoist assigns from ifs.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit dc975382 introduces napi support
but never calls napi_disable. This will generate a kernel oops
(kernel BUG at include/linux/netdevice.h:473!) every time, when
ndo_stop is called followed by ndo_start.
Add the missing napi_diable call.
Signed-off-by: NGeorg Hofmann <georg@hofmannsweb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Proviously we would only restart the FEC when PHY link or duplex state
changed. PHY does not always bring down the link for speed changes, in
which case we would not detect any change and keep FEC running.

Switching link speed without restarting the FEC results in the FEC being
stuck in an indefinite state, generating error conditions for every
packet.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Using devm_request_and_ioremap() can make the code cleaner and simpler.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

PCI header is not needed, so get rid of it.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Emitting netdev_alloc_skb and netdev_alloc_skb_ip_align OOM
messages is unnecessary as there is already a dump_stack
after allocation failures.

Other trivial changes around these removals:

Convert a few comparisons of pointer to 0 to !pointer.
Change flow to remove unnecessary label.
Remove now unused variable.
Hoist assignment from if.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

up stack ndo_start_xmit already hold lock.
fec_enet_start_xmit needn't spin lock.
stat_xmit just update fep->cur_tx
fec_enet_tx just update fep->dirty_tx

Reserve a empty bdb to check full or empty
cur_tx == dirty_tx    means full
cur_tx == dirty_tx +1 means empty

So needn't is_full variable.

Fix spin lock deadlock

=================================
[ INFO: inconsistent lock state ]
3.8.0-rc5+ #107 Not tainted
---------------------------------
inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
ptp4l/615 [HC1[1]:SC0[0]:HE0:SE1] takes:
 (&(&list->lock)->rlock#3){?.-...}, at: [<8042c3c4>] skb_queue_tail+0x20/0x50
 {HARDIRQ-ON-W} state was registered at:
 [<80067250>] mark_lock+0x154/0x4e8
 [<800676f4>] mark_irqflags+0x110/0x1a4
 [<80069208>] __lock_acquire+0x494/0x9c0
 [<80069ce8>] lock_acquire+0x90/0xa4
 [<80527ad0>] _raw_spin_lock_bh+0x44/0x54
 [<804877e0>] first_packet_length+0x38/0x1f0
 [<804879e4>] udp_poll+0x4c/0x5c
 [<804231f8>] sock_poll+0x24/0x28
 [<800d27f0>] do_poll.isra.10+0x120/0x254
 [<800d36e4>] do_sys_poll+0x15c/0x1e8
 [<800d3828>] sys_poll+0x60/0xc8
 [<8000e780>] ret_fast_syscall+0x0/0x3c

 *** DEADLOCK ***

 1 lock held by ptp4l/615:
  #0:  (&(&fep->hw_lock)->rlock){-.-...}, at: [<80355f9c>] fec_enet_tx+0x24/0x268
  stack backtrace:
  Backtrace:
  [<800121e0>] (dump_backtrace+0x0/0x10c) from [<80516210>] (dump_stack+0x18/0x1c)
  r6:8063b1fc r5:bf38b2f8 r4:bf38b000 r3:bf38b000
  [<805161f8>] (dump_stack+0x0/0x1c) from [<805189d0>] (print_usage_bug.part.34+0x164/0x1a4)
  [<8051886c>] (print_usage_bug.part.34+0x0/0x1a4) from [<80518a88>] (print_usage_bug+0x78/0x88)
  r8:80065664 r7:bf38b2f8 r6:00000002 r5:00000000 r4:bf38b000
  [<80518a10>] (print_usage_bug+0x0/0x88) from [<80518b58>] (mark_lock_irq+0xc0/0x270)
  r7:bf38b000 r6:00000002 r5:bf38b2f8 r4:00000000
  [<80518a98>] (mark_lock_irq+0x0/0x270) from [<80067270>] (mark_lock+0x174/0x4e8)
  [<800670fc>] (mark_lock+0x0/0x4e8) from [<80067744>] (mark_irqflags+0x160/0x1a4)
  [<800675e4>] (mark_irqflags+0x0/0x1a4) from [<80069208>] (__lock_acquire+0x494/0x9c0)
  r5:00000002 r4:bf38b2f8
  [<80068d74>] (__lock_acquire+0x0/0x9c0) from [<80069ce8>] (lock_acquire+0x90/0xa4)
  [<80069c58>] (lock_acquire+0x0/0xa4) from [<805278d8>] (_raw_spin_lock_irqsave+0x4c/0x60)
  [<8052788c>] (_raw_spin_lock_irqsave+0x0/0x60) from [<8042c3c4>] (skb_queue_tail+0x20/0x50)
  r6:bfbb2180 r5:bf1d0190 r4:bf1d0184
  [<8042c3a4>] (skb_queue_tail+0x0/0x50) from [<8042c4cc>] (sock_queue_err_skb+0xd8/0x188)
  r6:00000056 r5:bfbb2180 r4:bf1d0000 r3:00000000
  [<8042c3f4>] (sock_queue_err_skb+0x0/0x188) from [<8042d15c>] (skb_tstamp_tx+0x70/0xa0)
  r6:bf0dddb0 r5:bf1d0000 r4:bfbb2180 r3:00000004
  [<8042d0ec>] (skb_tstamp_tx+0x0/0xa0) from [<803561d0>] (fec_enet_tx+0x258/0x268)
  r6:c089d260 r5:00001c00 r4:bfbd0000
  [<80355f78>] (fec_enet_tx+0x0/0x268) from [<803562cc>] (fec_enet_interrupt+0xec/0xf8)
  [<803561e0>] (fec_enet_interrupt+0x0/0xf8) from [<8007d5b0>] (handle_irq_event_percpu+0x54/0x1a0)
  [<8007d55c>] (handle_irq_event_percpu+0x0/0x1a0) from [<8007d740>] (handle_irq_event+0x44/0x64)
  [<8007d6fc>] (handle_irq_event+0x0/0x64) from [<80080690>] (handle_fasteoi_irq+0xc4/0x15c)
  r6:bf0dc000 r5:bf811290 r4:bf811240 r3:00000000
  [<800805cc>] (handle_fasteoi_irq+0x0/0x15c) from [<8007ceec>] (generic_handle_irq+0x28/0x38)
  r5:807130c8 r4:00000096
  [<8007cec4>] (generic_handle_irq+0x0/0x38) from [<8000f16c>] (handle_IRQ+0x54/0xb4)
  r4:8071d280 r3:00000180
  [<8000f118>] (handle_IRQ+0x0/0xb4) from [<80008544>] (gic_handle_irq+0x30/0x64)
  r8:8000e924 r7:f4000100 r6:bf0ddef8 r5:8071c974 r4:f400010c
  r3:00000000
  [<80008514>] (gic_handle_irq+0x0/0x64) from [<8000e2e4>] (__irq_svc+0x44/0x5c)
  Exception stack(0xbf0ddef8 to 0xbf0ddf40)
Signed-off-by: NFrank Li <Frank.Li@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit 7f7d6c28 (net: fec: Ensure that initialization is done prior to
request_irq()) placed fec_ptp_init() into a point that ptp clock was not
available, which causes a division by zero in fec_ptp_start_cyclecounter():

[   17.895723] Division by zero in kernel.
[   17.899571] Backtrace:
[   17.902094] [<80012564>] (dump_backtrace+0x0/0x10c) from [<8056deec>]
(dump_stack+0x18/0x1c)
[   17.910539]  r6:bfba8500 r5:8075c950 r4:bfba8000 r3:bfbd0000
[   17.916284] [<8056ded4>] (dump_stack+0x0/0x1c) from [<80012688>]
(__div0+0x18/0x20)
[   17.923968] [<80012670>] (__div0+0x0/0x20) from [<802829c4>] (Ldiv0+0x8/0x10)
[   17.931140] [<80398534>] (fec_ptp_start_cyclecounter+0x0/0x110) from
[<80394f64>] (fec_restart+0x6c8/0x754)
[   17.940898] [<8039489c>] (fec_restart+0x0/0x754) from [<803969a0>]
(fec_enet_adjust_link+0xdc/0x108)
[   17.950046] [<803968c4>] (fec_enet_adjust_link+0x0/0x108) from [<80390bc4>]
(phy_state_machine+0x178/0x534)
...

Fix this by rearraging the code so that fec_ptp_init() is called only after
the clocks have been properly acquired.

Tested on both mx53 and mx6 platforms.
Reported-by: NJim Baxter <jim_baxter@mentor.com>
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently request_irq() is called prior to fec_enet_init() and fec_ptp_init(),
which causes the following crash on a mx53qsb:

Unable to handle kernel NULL pointer dereference at virtual address 00000002
pgd = 80004000
[00000002] *pgd=00000000
Internal error: Oops: 5 [#1] SMP ARM
Modules linked in:
CPU: 0    Not tainted  (3.8.0-rc7-next-20130215+ #346)
PC is at fec_enet_interrupt+0xd0/0x348
LR is at fec_enet_interrupt+0xb8/0x348
pc : [<80372b7c>]    lr : [<80372b64>]    psr: 60000193
sp : df855c20  ip : df855c20  fp : df855c74
r10: 00000516  r9 : 1c000000  r8 : 00000000
r7 : 00000000  r6 : 00000000  r5 : 00000000  r4 : df9b7800
r3 : df9b7df4  r2 : 00000000  r1 : 00000000  r0 : df9b7d34

Ensure that such initialization functions are called prior to requesting the
interrupts, so that all necessary the data structures are in place when the
irqs occur.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Check whether the phy-reset GPIO is valid, prior to requesting it.

In the case a board does not provide a phy-reset GPIO, just returns immediately.

With such gpio validation in place, it is also safe to change from pr_debug to
dev_err in the case the gpio request fails.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Old method will cause init spinlock twice.
New method will avoid init spinlock twice and fix miss init spinlock
at fec_restart.

BUG: spinlock bad magic on CPU#1, swapper/0/1
lock: 0xbfae0f8c, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
Backtrace:
 [<80011d54>] (dump_backtrace+0x0/0x10c) from [<804e7800>] (dump_stack+0x18/0x1c)
 r6:bfae0000 r5:bfae0f8c r4:00000000 r3:806c1310
 [<804e77e8>] (dump_stack+0x0/0x1c) from [<804e9f20>] (spin_dump+0x80/0x94)
 [<804e9ea0>] (spin_dump+0x0/0x94) from [<804e9f60>] (spin_bug+0x2c/0x30)
 r5:805f6f8c r4:bfae0f8c
 [<804e9f34>] (spin_bug+0x0/0x30) from [<80257984>] (do_raw_spin_lock+0x170/0x1b0                                         )
 r5:806b4950 r4:bfae0f8c
 [<80257814>] (do_raw_spin_lock+0x0/0x1b0) from [<804ed15c>] (_raw_spin_lock_irqs                                         ave+0x18/0x20)
 [<804ed144>] (_raw_spin_lock_irqsave+0x0/0x20) from [<8033c694>] (fec_ptp_start_                                         cyclecounter+0x3c/0x120)
 r4:bfae0f8c r3:00000002
 [<8033c658>] (fec_ptp_start_cyclecounter+0x0/0x120) from [<80339e08>] (fec_resta                                         rt+0x56c/0x5f8)
 r8:00000000 r7:806e6f48 r6:00000112 r5:806b4950 r4:bfae0000
 [<8033989c>] (fec_restart+0x0/0x5f8) from [<8033b9e4>] (fec_probe+0x508/0xa48)
Signed-off-by: NFrank Li <Frank.Li@freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>