This is a little more efficient and avoids the warning

 WARNING: possible circular locking dependency detected
 4.14.0-rc7-00010 #16 Not tainted
 ------------------------------------------------------
 kworker/2:1/70 is trying to acquire lock:
  (prepare_lock){+.+.}, at: [<c049300c>] clk_prepare_lock+0x80/0xf4

 but task is already holding lock:
  (i2c_register_adapter){+.+.}, at: [<c0690b04>]
		i2c_adapter_lock_bus+0x14/0x18

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #1 (i2c_register_adapter){+.+.}:
        rt_mutex_lock+0x44/0x5c
        i2c_adapter_lock_bus+0x14/0x18
        i2c_transfer+0xa8/0xbc
        i2c_smbus_xfer+0x20c/0x5d8
        i2c_smbus_read_byte_data+0x38/0x48
        m41t80_sqw_is_prepared+0x18/0x28
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

This is a little more efficient, and avoids the warning

 WARNING: possible circular locking dependency detected
 4.14.0-rc7-00007 #14 Not tainted
 ------------------------------------------------------
 alsactl/330 is trying to acquire lock:
 (prepare_lock){+.+.}, at: [<c049300c>] clk_prepare_lock+0x80/0xf4

 but task is already holding lock:
 (i2c_register_adapter){+.+.}, at: [<c0690ae0>]
		i2c_adapter_lock_bus+0x14/0x18

 which lock already depends on the new lock.

 the existing dependency chain (in reverse order) is:

 -> #1 (i2c_register_adapter){+.+.}:
        rt_mutex_lock+0x44/0x5c
        i2c_adapter_lock_bus+0x14/0x18
        i2c_transfer+0xa8/0xbc
        i2c_smbus_xfer+0x20c/0x5d8
        i2c_smbus_read_byte_data+0x38/0x48
        m41t80_sqw_recalc_rate+0x24/0x58
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Previously it was returning the best of
32768, 8192, 1024, 64, 2, 0

Now, best of
32768, 8192, 4096, 2048, 1024, 512, 256, 128,
64, 32, 16, 8, 4, 2, 1, 0
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Previously it was returning -EINVAL upon success.
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Note that alarms are not currently implemented.

64 bytes of nvmem is supported and exposed in
sysfs (# is the instance number, starting with 0):

	/sys/bus/nvmem/devices/pcf85363-#/nvmem
Signed-off-by: Eric Nelson <eric@nelint.com>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Tested-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Register an nvmem device to expose the 3 scratch registers (total of 12
bytes) to both userspace and kernel space.
Reviewed-by: Sekhar Nori <nsekhar@ti.com>
Tested-by: Keerthy <j-keerthy@ti.com>
Reviewed-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

This removes a possible race condition and crash and allows for further
improvement of the driver.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

If pinctrl_register() fails probe will return with an error without locking
the RTC and disabling pm_runtime.
Set ret and jump to err instead.

Fixes: 97ea1906 ("rtc: omap: Support ext_wakeup configuration")
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

The driver doesn't have a struct of_device_id table but supported devices
are registered via Device Trees. Worse, the compatible is documented but
doesn't currently match the driver.

Add the proper compatible to the driver.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Make Epson RX8130 device tree and ACPI aware.

Fixes: ee0981be ("rtc: ds1307: Add support for Epson RX8130CE")
Signed-off-by: Bastian Stender <bst@pengutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

I work for MediaTek on maintaining the MediaTek SoC based RTC driver for
the existing SoCs and keep adding support for the following SoCs in the
future.

Cc: Eddie Huang <eddie.huang@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Give a better description for original MediaTek RTC driver as PMIC based
RTC in order to distinguish SoC based RTC. Also turning all words with
Mediatek to MediaTek here.

Cc: Eddie Huang <eddie.huang@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Acked-by: Eddie Huang <eddie.huang@mediatek.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

This patch introduces the driver for the RTC on MT7622 SoC.
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Reviewed-by: Yingjoe Chen <yingjoe.chen@mediatek.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Add device-tree binding for MediaTek SoC based RTC

Cc: devicetree@vger.kernel.org
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Add support for reading and writing the RTC offset register, converting
it to the corresponding parts-per-billion value.

When setting the drift, the PCF8523 has two modes: one applies the
adjustment every two hours, the other applies the adjustment every
minute.  We select between these two modes according to which ever
gives the closest PPB value to the one requested.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Add support for trimming the RTC using the offset mechanism.  This RTC
supports two modes: low update mode and high update mode.  Low update
mode has finer precision than high update mode, so we use the low mode
where possible.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

The RTC offset correction documentation is not very clear about the
exact relationship between "offset" and the effect it has on the RTC.
Supplement the documentation with an equation giving the relationship.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Instead of adding a binary sysfs attribute from the driver (which suffers
from a race condition as the attribute appears after the device), use the
core to register an nvmem device.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Disabling interrupts when removing the driver is bad practice as this will
prevent some platform from waking up when using that RTC.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

This allows for future improvement of the driver.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

There is a race condition that can happen if abx80x_probe() fails after the
rtc registration succeeded. Solve that by moving the registration at the
end of the probe function.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

This allows for future improvement of the driver.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Instead of adding a binary sysfs attribute from the driver (which suffers
from a race condition as the attribute appears after the device), use the
core to register an nvmem device.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

This allows for future improvement of the driver.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Instead of adding a binary sysfs attribute from the driver (which suffers
from a race condition as the attribute appears after the device), use the
core to register an nvmem device.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

This allows for future improvement of the driver.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

On some platforms, the interrupt for the PL031 is optional.  Avoid
trying to claim the interrupt if it's not specified.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

If the RTC has no interrupt, there is little point in exposing the RTC
alarm capabilities, as it can't be used as a wakeup source nor can it
deliver an event to userspace.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Use the devm_* APIs for allocating memory and mapping the memory in
the probe function to relieve the driver from having to deal with
this in the cleanup paths.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

The AMBA device IDs should be marked const.  Make that so.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

We don't need both "ret" and "err" when they do the same thing.  All the
functions called here return zero on success or negative error codes.
It's more clear to return a literal zero at the end instead of
"return ret;"
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

The current timeout for waiting for WRDY is not always sufficient. Always
increase it to 10000 even on JZ4740. This is technically only required on
JZ4780, where the current symptoms seen after a hard reboot are:

  jz4740-rtc 10003000.rtc: rtc core: registered 10003000.rtc as rtc0
  jz4740-rtc 10003000.rtc: Could not write to RTC registers
  jz4740-rtc: probe of 10003000.rtc failed with error -5
Suggested-by: Alex Smith <alex.smith@imgtec.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Trivial fix in error message with duplicate 'write'
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

The current code for checking and fixing the weekday in ds1307_probe
faces some issues:
- This check is applied to all chips even if its applicable (AFAIK)
  to mcp794xx only
- The check uses MCP794XX constants for registers and bits even though
  it's executed also on other chips (ok, this could be fixed easily)
- It relies on tm_wday being properly populated when core calls set_time
  and set_alarm. This is not guaranteed at all.

First two issue we could solve by moving the check to the
mcp794xx-specific initialization (where also VBATEN flag is set).

The proposed alternative is in the set_alarm path for mcp794xx only and
calculates the alarm weekday based on the current weekday in the RTC
timekeeping regs and the difference between alarm date and current date.
So we are fine with any weekday even if it doesn't match the date.

Still there are cases where this could fail, e.g.:
- rtc date/time + weekday have power-on-reset default values
- alarm is set to actual date/time + x
- set_time is called (may change diff between rtc weekday and actual
  weekday)

But similar issues we have with the current code too:
- rtc date/time + weekday have power-on-reset default values
- alarm is set to rtc date/time + x
- set_time is called before the alarm triggers

Using random rtc date/time with relative alarms simply can interfere
with set_time. I'm not totally convinced of either option yet.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

If there is any non expired timer in the queue, the RTC alarm is never set.
This is an issue when adding a timer that expires before the next non
expired timer.

Ensure the RTC alarm is set in that case.

Fixes: 2b2f5ff0 ("rtc: interface: ignore expired timers when enqueuing new timers")
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

The vendor string for Microcrystal is microcrystal.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Pull UBI updates from Richard Weinberger:
 "Minor improvements"

* tag 'upstream-4.14-rc1' of git://git.infradead.org/linux-ubifs:
  UBI: Fix two typos in comments
  ubi: fastmap: fix spelling mistake: "invalidiate" -> "invalidate"
  ubi: pr_err() strings should end with newlines
  ubi: pr_err() strings should end with newlines
  ubi: pr_err() strings should end with newlines

Pull UML updates from Richard Weinberger:

 - minor improvements

 - fixes for Debian's new gcc defaults (pie enabled by default)

 - fixes for XSTATE/XSAVE to make UML work again on modern systems

* 'for-linus-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: return negative in tuntap_open_tramp()
  um: remove a stray tab
  um: Use relative modversions with LD_SCRIPT_DYN
  um: link vmlinux with -no-pie
  um: Fix CONFIG_GCOV for modules.
  Fix minor typos and grammar in UML start_up help
  um: defconfig: Cleanup from old Kconfig options
  um: Fix FP register size for XSTATE/XSAVE

Pull networking fixes from David Miller:

 1) Fix hotplug deadlock in hv_netvsc, from Stephen Hemminger.

 2) Fix double-free in rmnet driver, from Dan Carpenter.

 3) INET connection socket layer can double put request sockets, fix
    from Eric Dumazet.

 4) Don't match collect metadata-mode tunnels if the device is down,
    from Haishuang Yan.

 5) Do not perform TSO6/GSO on ipv6 packets with extensions headers in
    be2net driver, from Suresh Reddy.

 6) Fix scaling error in gen_estimator, from Eric Dumazet.

 7) Fix 64-bit statistics deadlock in systemport driver, from Florian
    Fainelli.

 8) Fix use-after-free in sctp_sock_dump, from Xin Long.

 9) Reject invalid BPF_END instructions in verifier, from Edward Cree.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (43 commits)
  mlxsw: spectrum_router: Only handle IPv4 and IPv6 events
  Documentation: link in networking docs
  tcp: fix data delivery rate
  bpf/verifier: reject BPF_ALU64|BPF_END
  sctp: do not mark sk dumped when inet_sctp_diag_fill returns err
  sctp: fix an use-after-free issue in sctp_sock_dump
  netvsc: increase default receive buffer size
  tcp: update skb->skb_mstamp more carefully
  net: ipv4: fix l3slave check for index returned in IP_PKTINFO
  net: smsc911x: Quieten netif during suspend
  net: systemport: Fix 64-bit stats deadlock
  net: vrf: avoid gcc-4.6 warning
  qed: remove unnecessary call to memset
  tg3: clean up redundant initialization of tnapi
  tls: make tls_sw_free_resources static
  sctp: potential read out of bounds in sctp_ulpevent_type_enabled()
  MAINTAINERS: review Renesas DT bindings as well
  net_sched: gen_estimator: fix scaling error in bytes/packets samples
  nfp: wait for the NSP resource to appear on boot
  nfp: wait for board state before talking to the NSP
  ...