pwm: fsl-ftm: Clean up the code

This patch intends to prepare for converting to direct regmap API usage.

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: fsl-ftm: Convert to direct regmap API usage

The regmap core supports different endian modes for devices. This patch
convert to direct regmap API usage, preparing to support big endianness
for LS1 SoC.

Using the regmap framework it will be easy to support devices that only
differ in endianness with the same device driver.

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: fsl-ftm: Document 'big-endian' property

The same FTM PWM device can have a different endianness on different
SoCs. The device tree provides a property to describing this so that an
operating system device driver can handle all variants of the device.
Refer to the table below for the endianness of the FTM PWM block as
integrated into the existing SoCs:

	SoC     | FTM-PWM endianness
	--------+-------------------
	Vybrid  | LE
	LS1     | BE
	LS2     | LE

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: fsl-ftm: Select REGMAP_MMIO

Commit 42fa98a9c360 ("pwm: fsl-ftm: Convert to direct regmap API usage")
introduced the following error when REGMAP_MMIO=n:

drivers/built-in.o: In function `fsl_pwm_probe':
>> pwm-fsl-ftm.c:(.text+0xd7d7): undefined reference to `devm_regmap_init_mmio_clk'

Select select REGMAP_MMIO in order to fix this error.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: lpss: Add ACPI and PCI IDs for Intel Braswell

This is pretty much the same as Baytrail PWM. Only difference is that the
input clock runs on different frequency.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: lpss: Properly split driver to parts

The driver consists of core, PCI, and platform parts. It would be better
to split them into separate files.

The platform driver is now called pwm-lpss-platform. Thus, previously
set CONFIG_PWM_LPSS=m is not enough to build it. But we are on the safe
side since it seems no one from outside Intel is using it for now.

While here, move to use macros module_pci_driver() and
module_platform_driver().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Alan Cox <alan@linux.intel.com>
[thierry.reding: change select to depends on PWM_LPSS, cleanup]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: lpss: pci: Move to use pcim_enable_device()

Let's use managed functions for this driver.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: lpss: Fix build failure on PowerPC

An x86 build seems to pull in the linux/io.h include indirectly. On
PowerPC that doesn't happen and the build breaks due to the readl() and
writel() functions not being declared. Fix this by explicitly including
linux/io.h.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: lpss: use c99 initializers in structures

Use c99 initializers for structures.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@decl@
identifier i1,fld;
type T;
field list[n] fs;
@@

struct i1 {
 fs
 T fld;
 ...};

@bad@
identifier decl.i1,i2;
expression e;
initializer list[decl.n] is;
@@

struct i1 i2 = { is,
+ .fld = e
- e
 ,...};
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
[thierry.reding: rebased and applied same fix for Braswell]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: lpss: make it buildable only on X86

There is no sign of this IP block on non-x86 architectures and rather will not
be. Thus, make this explicit by applying a direct dependency to X86.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: Fix possible ZERO_SIZE_PTR pointer dereferencing error.

Since we cannot make sure the 'chip->npwm' will always be none zero here,
and then if either equal to zero, the kzalloc() will return ZERO_SIZE_PTR,
which equals to ((void *)16).

So this patch fix this with just doing the zero check before calling kzalloc().

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: imx: Fix the macro MX3_PWMCR_PRESCALER(x) definition

This patch adds missing parentheses around the argument of the macro
MX3_PWMCR_PRESCALER(x) to avoid any potential macro expansion issue.

Reported-by: Lothar Waßmann <LW@KARO-electronics.de>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawn.guo@freescale.com>
Cc: Lothar Waßmann <LW@KARO-electronics.de>
Cc: linux-pwm@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Liu Ying <Ying.Liu@freescale.com>
Acked-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: imx: Cleanup indentation for register definitions

This patch contains no logic change to cleanup indentation for register
definitions only.

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawn.guo@freescale.com>
Cc: Lothar Waßmann <LW@KARO-electronics.de>
Cc: linux-pwm@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Liu Ying <Ying.Liu@freescale.com>
Acked-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: imx: Avoid sample FIFO overflow for i.MX PWM version2

The i.MX PWM version2 is embedded in several i.MX SoCs, such as i.MX27,
i.MX51 and i.MX6SL.  There is a 4-word (16 bit) sample FIFO in this IP.
Each FIFO slot determines the duty period of a PWM waveform in one full
cycle.  The IP spec mentions that we should not write a fourth sample
because the FIFO will become full and triggers a FIFO write error (FWE)
which will prevent the PWM from starting once it is enabled.  In order
to avoid any sample FIFO overflow issue, this patch clears all sample
FIFO by doing software reset in the configuration hook when the
controller is disabled or waits for a full PWM cycle to get a
relinquished FIFO slot when the controller is enabled and the FIFO is
fully loaded.

The FIFO overflow issue can be reproduced by the following commands on
the i.MX6SL EVK platform, assuming we use PWM2 for the debug LED which
is driven by the pin HSIC_STROBE and the maximal brightness is 255.

	echo 0   > /sys/class/leds/user/brightness
	echo 0   > /sys/class/leds/user/brightness
	echo 0   > /sys/class/leds/user/brightness
	echo 0   > /sys/class/leds/user/brightness
	echo 255 > /sys/class/leds/user/brightness

Here, FWE happens (PWMSR register reads 0x58) and the LED can not be
lighten.

Another way to reproduce the FIFO overflow issue is to run this script:

	while true;
		do echo 255 > /sys/class/leds/user/brightness;
	done

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Shawn Guo <shawn.guo@freescale.com>
Cc: Lothar Waßmann <LW@KARO-electronics.de>
Cc: linux-pwm@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Liu Ying <Ying.Liu@freescale.com>
Acked-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: rockchip: Allow polarity invert on rk3288

The rk3288 has the ability to invert the polarity of the PWM.  Let's
enable that ability.  Note that this increases pwm_cells to 3 for
rk3288.

Signed-off-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Caesar Wang <caesar.wang@rock-chips.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: Fix uninitialized warnings in pwm_get()

With some versions of gcc (e.g. 4.1.2):

drivers/pwm/core.c: In function ‘pwm_get’:
drivers/pwm/core.c:610: warning: ‘polarity’ may be used uninitialized in this function
drivers/pwm/core.c:609: warning: ‘period’ may be used uninitialized in this function

While these are false positives, we can get rid of them by refactoring
the code to store a pointer to the best match, as suggested before by
Thierry Reding. This does require moving the mutex_unlock() down.

Fixes: d717ea73e36dd565 ("pwm: Fix period and polarity in pwm_get() for non-perfect matches")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
ext4: convert ext4_dx_find_entry() to use the ERR_PTR convention

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4: convert ext4_getblk() to use the ERR_PTR convention

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4: convert ext4_bread() to use the ERR_PTR convention

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
ext4: convert dx_probe() to use the ERR_PTR convention

Signed-off-by: Theodore Ts'o <tytso@mit.edu>