Merge branch 'for-next/imx'

watchdog: i.MX: fix i.MX6 reset ...

According to the Errata ERR004346 (WDOG: WDOG SRS bit requires to be written
twice), add another two writes to ensure there must be at least two
writes happen in the same one 32kHz clock period.
Without this two additional writes, the system will not reset always.

Tested with i.MX6Quad and i.MX6 UltraLite

Signed-off-by: Christian Hemp <c.hemp@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

i.MX/WD: setup the watchdog according to its datasheet ...

From earlier SoCs like the i.MX21 up to i.MX7 their datasheets states
after reset the watchdog timer has to be set first prior enabling the
watchdog itself. This change do it this way.

Signed-off-by: Juergen Borleis <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

watchdog: i.MX: Fix internal/external reset ...

The watchdog can either reset only the SoC or assert the WDOG_B
output signal instead. On some boards it's necessary to use the
external WDOG_B output to make sure that external devices like the
PMIC are also properly resetted. This has been fixed in the Linux
driver which honours a fsl,ext-reset-output device tree property
to select between both ways. Do the same in the barebox driver.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

watchdog: i.MX: add soc_reset operation ...

On i.MX21 watchdog type the reset operation is really different
from the watchdog enable/set timeout operation, so create an
extra callback for this instead of folding both things together.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

driver: replace dev_request_mem_region with dev_request_mem_resource ...

dev_request_mem_region doesn't work properly one some SoCs on which
PTR_ERR() values clash with valid return values from dev_request_mem_region.
Replace them with dev_request_mem_resource where possible.

This patch has been generated with the following semantic patch:

// <smpl>
@@
expression d;
expression n;
expression io;
identifier func;
@@
func(...) {
+struct resource *iores;
<+...
-io = dev_request_mem_region(d, n);
-if (IS_ERR(io)) {
+iores = dev_request_mem_resource(d, n);
+if (IS_ERR(iores)) {
...
-	return PTR_ERR(io);
-}
+	return PTR_ERR(iores);
+}
+io = IOMEM(iores->start);
...+>
}

@@
expression d;
expression n;
expression io;
identifier func;
@@
func(...) {
+struct resource *iores;
<+...
-io = dev_request_mem_region(d, n);
-if (IS_ERR(io)) {
+iores = dev_request_mem_resource(d, n);
+if (IS_ERR(iores))
-	return PTR_ERR(io);
-}
+	return PTR_ERR(iores);
+io = IOMEM(iores->start);
...+>
}

@@
expression d;
expression n;
expression io;
identifier func;
@@
func(...) {
+struct resource *iores;
<+...
-io = dev_request_mem_region(d, n);
-if (IS_ERR(io)) {
-	ret = PTR_ERR(io);
+iores = dev_request_mem_resource(d, n);
+if (IS_ERR(iores)) {
+	ret = PTR_ERR(iores);
...
}
+io = IOMEM(iores->start);
...+>
}

@@
expression d;
expression n;
expression io;
identifier func;
@@
func(...) {
+struct resource *iores;
<+...
-io = dev_request_mem_region(d, n);
+iores = dev_request_mem_resource(d, n);
+if (IS_ERR(iores))
+	return PTR_ERR(iores);
+io = IOMEM(iores->start);
...+>
}

@@
identifier func;
@@
func(...) {
<+...
struct resource *iores;
-struct resource *iores;
...+>
}
// </smpl>

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

driver: Fix return check of dev_request_mem_region ...

dev_request_mem_region returns an ERR_PTR, fix places which check for a
NULL pointer instead. This patch has been generated with this semantic
patch, written by me and improved by Andrey Smirnov:

// <smpl>
@@
expression e;
expression e1;
@@
e = dev_request_mem_region(...);
...
-if (!e)
-	return e1;
+if (IS_ERR(e))
+	return PTR_ERR(e);

@ rule1 @
expression e;
@@
e = dev_request_mem_region(...);

@@
expression rule1.e;
identifier ret, label;
constant errno;
@@
if (!e) {
	...
(
-	ret = -errno;
+	ret = PTR_ERR(e);
	...
	goto label;
|
-	return -errno;
+	return PTR_ERR(e);
)
}

@depends on rule1@
expression rule1.e;
@@
-	if (e == NULL)
+	if (IS_ERR(e))
{
...
}
// </smpl>

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>

wdog: imx-wd: watchdog cannot be disabled again ...

The i.MX21/i.MX6 watchdog cannot be disabled after it was activated.
Bit 2 (WDE) cannot be set to 0 again. Notify the user about that by
returning -ENOSYS.

Signed-off-by: Stefan Christ <s.christ@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

watchdog: Give watchdogs a name ...

This adds a dev and name member to struct watchdog which helps distinguishing
between different watchdogs. Also add some debugging aids.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

restart: replace reset_cpu with registered restart handlers ...

This replaces the reset_cpu() function which every SoC or board must
provide with registered handlers. This makes it possible to have multiple
reset functions for boards which have multiple ways to reset the machine.
Also boards which have no way at all to reset the machine no longer
have to provide a dummy reset_cpu() function.

The problem this solves is that some machines have external PMICs or
similar to reset the system which have to be preferred over the
internal SoC reset, because the PMIC can reset not only the SoC but also
the external devices.

To pick the right way to reset a machine each handler has a priority. The
default priority is 100 and all currently existing restart handlers are
registered with this priority. of_get_restart_priority() allows to retrieve
the priority from the device tree which makes it possible for boards to
give certain restart handlers a higher priority in order to use this one
instead of the default one.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

watchdog: imxwd: remove remove callback ...

The imxwd is for resetting the system, so we should not unregister it
during shutdown_barebox() as it may leave us without a restart handler.
Only a bug (not setting reset_wd to NULL in remove()) made the whole
thing work.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

of: use 'const void *' for struct of_device_id.data ...

Since 2011 barebox' of_device_id struct uses unsigned long type for data field:

    struct of_device_id {
            char *compatible;
            unsigned long data;
    };

Almost always struct of_device_id.data field are used as pointer
and need 'unsigned long' casting.

E.g. see 'git grep -A 4 of_device_id drivers/' output:

    drivers/ata/sata-imx.c:static __maybe_unused struct of_device_id imx_sata_dt_ids[] = {
    drivers/ata/sata-imx.c- {
    drivers/ata/sata-imx.c-         .compatible = "fsl,imx6q-ahci",
    drivers/ata/sata-imx.c-         .data = (unsigned long)&data_imx6,
    drivers/ata/sata-imx.c- }, {

Here is of_device_id struct in linux kernel v4.0:

    struct of_device_id {
            char name[32];
            char type[32];
            char compatible[128];
            const void *data;
    };

Changing of_device_id.data type to 'const void *data' will increase
barebox' linux kernel compatibility and decrease number of 'unsigned
long' casts.

Part of the patch was done using the 'coccinelle' tool with the
following semantic patch:

    @rule1@
    identifier dev;
    identifier type;
    identifier func;
    @@
    func(...) {
    <...
    - dev_get_drvdata(dev, (unsigned long *)&type)
    + dev_get_drvdata(dev, (const void **)&type)
    ...>
    }
    @rule2@
    identifier dev;
    identifier type;
    identifier func;
    identifier data;
    @@
    func(...) {
    <...
    - dev_get_drvdata(dev, (unsigned long *)&type->data)
    + dev_get_drvdata(dev, (const void **)&type->data)
    ...>
    }

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

wdog: imx-wd: Disable watchdog powerdown counter ...

Disable the watchdog powerdown counter at start. Otherwise this may
trigger a reset or poweroff over the WDOG_B line to a PMIC. This counter
is set to 16 seconds after poweron.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

wdog: imx-wd: Introduce ops struct for imx21/imx1 ...

Replace the set_timeout function in the device platform data by an ops
struct which stores a set_timeout and init function.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

watchdog: i.MX: check requested mem region in imx_wd_probe() ...

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

reset_source: rename set_reset_source to reset_source_set ...

To get all reset source related functions into the same function
namespace.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

treewide: Add missing includes ...

A lot of files rely on include/driver.h including include/of.h (and
this including include/errno.h. include the files explicitly so we can
eventually get rid of including of.h from driver.h

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Use new device_platform_driver() macro for drivers ...

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ARM i.MX: move reset source detection code ...

- for i.MX1 the register is in the System Control unit, so move
  the code to arch/arm/mach-imx/imx1.c
- for the other i.MX the register is in the watchdog unit, so move
  the code to drivers/watchdog/imxwd.c

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

ARM i.MX/watchdog: Make i.MX watchdog driver the reset source on i.MX ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

watchdog: Add i.MX watchdog support ...

This adds a driver for the watchdog found on i.MX1-i.MX6.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>