treewide: make use of PTR_ERR_OR_ZERO ...

PTR_ERR_OR_ZERO is designed to replace boiler plate like:

	if (IS_ERR(x))
		return PTR_ERR(x);
	return 0;

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

pwm: Replace license and copyright boilerplate by SPDX identfiers ...

This adapts all files that were identifed by licensecheck
(https://salsa.debian.org/build-common-team/licensecheck.git) as
licensed under the GPL and that have a (IMHO) clear copyright statement.

The advantage is that these specifiers are machine-parseable which helps
license conformance, e.g. for packaging barebox in Debian.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

drivers: mark first batch of compilable drivers for COMPILE_TEST ...

All of these drivers have a runtime dependency on SoC peripherals, but
can nevertheless be compile-tested. Add COMPILE_TEST as an alternate
dependency.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

drivers: explicitly select dependency STMP_DEVICE for i.MX23/28 drivers ...

Some of the i.MXs drivers can be build tested even if building for other
platforms. Support adding a future COMPILE_TEST dependency to some of
these drivers by explicitly having their Kconfig symbol select STMP_DEVICE
if the driver calls stmp_reset_block.

This has not been necessary for the normal build, because the ARCH
symbols for the IMX23 and IMX28 already selected STMP_DEVICE.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PWM: add support for STM32 ...

This driver adds support for PWM driver on STM32 platform
based on the Linux v5.4 support.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PWM: core: add apply API support for polarity ...

Some PWM chips support outputting an inverted PWM signal.
Add API support for this.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PWM: core: apply initial state in of_pwm_request ...

This functions prepares a state that can later be tweaked and applied
to the PWM device with pwm_apply_state(). This is a convenient function
that first retrieves the current PWM state and the replaces the period
with the reference values defined in pwm->args.
Once the function returns, you can adjust the ->enabled and ->duty_cycle
fields according to your needs before calling pwm_apply_state().

Signed-off-by: Ahmad Fatoum <ahmad@a3f.at>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PWM: core: retire pwm_set_period ...

Client code can use pwm_apply_state or pwm_config to set period as well
as duty cycle. Having a pwm_set_period thus doesn't add any value.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PWM: core: remove old PWM API in favor of Linux ->apply ...

Linux has the new atomic PWM API in addition to the old one for backward
compatibility. We only have three PWM drivers in here, so port them over
to the new ->apply API.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PWM: core: group PWM state into new struct pwm_state ...

As a prerequisite for moving to the new apply API, we need to group all
state into one struct that we can apply at once. Prepare for this.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PWM: core: remove ineffectual pwm_{set,get}_duty_cycle ...

The setter sets a value unused anywhere, but in the getter.
As the functions are unused, just drop them.
There's pwm_config that can be used for this instead.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PWM: core: remove FLAG_ENABLED ...

In preparation for moving to a struct pwm_state like Linux does, turn
the flag into a variable.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PWM: pxa: make MMIO writes always little endian ...

Even when the processor runs in big-endian mode, the peripheral is
little-endian and is used as such in Linux. Do here likewise.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

PWM: pxa: remove unused struct members ...

Both duty_ns and period_ns are stored to, but never read. Drop them.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

drivers: Introduce dev_set_name() ...

Introduce dev_set_name() in order to hide implementation details of
setting device's name so it'd be easier to change it.

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

param: make parameter functions more consistent ...

This patch creates a consitent set of device parameter functions.

With this we have: dev_add_param_<type><access>

"type" is one of: int32, uint32, int64, uint64, string, mac, ipv4, enum, bitmask
The improvement here is that we now can exactly specify the width of the
int type parameters and also correctly distinguish between signed and
unsigned variables which means that a variable no longer ends up with
INT_MAX when it's assigned -1.

"access" can be empty for regular read/write parameter, "_ro" for readonly
parameters which get their value from a variable pointer in the
background or "_fixed" for parameters which are set to a fixed value
(without a pointer in the background).

Some more exotic types are not (yet) implemented, like
dev_add_param_ip_ro.

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

PWM: update enable status when using the internal API ...

Without these, 'devinfo pwmX' will show enabled=0 even though the PWM
was enabled (for example by a pwm-backlight).

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

string: Fix (v)asprintf prototypes ...

Our asprintf and vasprintf have different prototypes than the glibc
functions. This causes trouble when we want to share barebox code
with userspace code. Change the prototypes for (v)asprintf to match
the glibc prototypes. Since the current (v)asprintf are convenient
to use change the existing functions to b(v)asprintf.

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>

PWM: Add MXS PWM support ...

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

PWM: Allow multiple PWMs per device node ...

Matching a device node is enough since a device node may have
multiple PWMs. Check for a id aswell.

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>

PWM: i.MX: register successfully without alias ...

When a PWM does not have an of alias generate a name from the
base address so that we can register it successfully.

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

resource: Let dev_request_mem_region return an error pointer ...

For all users fix or add the error check.

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

PWM: Implement devicetree support ...

This implements of_pwm_request() for PWM client drivers.

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

PWM: Add functions for getting/setting period/duty cycle ...

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

PWM: Add i.MX PWM driver ...

The Kernel driver from Linux-3.13 with some adjustments for
barebox.

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

PWM: pxa: use pwmx as devname ...

As this changes the name of the pwm we also have to adjust it in
pwm_request.

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

PWM: Use a separate device for PWMs ...

Instead of directly using the hardware devicet for PWMs register
a logical PWM device so that the user operates on pwmx devices rather
than pxa-pwmx.

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

pwm: sanity check values before passing them to the drivers ...

Check for valid period size before calling ops->config. This fixes
the pxa driver which otherwise does a division by zero. While at
it, also check for duty_ns being smaller or equal to period_ns.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Robert Jarzmik <robert.jarzmik@free.fr>