linux.git/drivers/pwm, branch v4.6.3

pwm: fsl-ftm: Use flat regmap cache

2016-04-14T14:54:00+00:00

Use flat regmap cache to avoid lockdep warning at probe:

[    0.697285] WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:2755 lockdep_trace_alloc+0x15c/0x160()
[    0.697449] DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags))

The RB-tree regmap cache needs to allocate new space on first writes.
However, allocations in an atomic context (e.g. when a spinlock is held)
are not allowed. The function regmap_write calls map->lock, which
acquires a spinlock in the fast_io case. Since the pwm-fsl-ftm driver
uses MMIO, the regmap bus of type regmap_mmio is being used which has
fast_io set to true.

The MMIO space of the pwm-fsl-ftm driver is reasonable condense, hence
using the much faster flat regmap cache is anyway the better choice.

Signed-off-by: Stefan Agner 
Cc: Mark Brown 
Signed-off-by: Thierry Reding

pwm: omap-dmtimer: Add debug message for effective period and duty cycle

2016-03-23T16:11:48+00:00

After going through the math and constraints checking to compute load
and match values, it is helpful to know what the resultant period and
duty cycle are.

Signed-off-by: David Rivshin 
Acked-by: Neil Armstrong 
Signed-off-by: Thierry Reding

pwm: omap-dmtimer: Round load and match values rather than truncate

2016-03-23T16:11:47+00:00

When converting period and duty_cycle from nanoseconds to fclk cycles,
the error introduced by the integer division can be appreciable, especially
in the case of slow fclk or short period. Use DIV_ROUND_CLOSEST_ULL() so
that the error is kept to +/- 0.5 clock cycles.

Fixes: 6604c6556db9 ("pwm: Add PWM driver for OMAP using dual-mode timers")
Signed-off-by: David Rivshin 
Acked-by: Neil Armstrong 
Signed-off-by: Thierry Reding

pwm: omap-dmtimer: Add sanity checking for load and match values

2016-03-23T16:11:46+00:00

Add sanity checking to ensure that we do not program load or match values
that are out of range if a user requests period or duty_cycle values which
are not achievable. The match value cannot be less than the load value (but
can be equal), and neither can be 0xffffffff. This means that there must be
at least one fclk cycle between load and match, and another between match
and overflow.

Fixes: 6604c6556db9 ("pwm: Add PWM driver for OMAP using dual-mode timers")
Signed-off-by: David Rivshin 
Acked-by: Neil Armstrong 
[thierry.reding@gmail.com: minor coding style cleanups]
Signed-off-by: Thierry Reding

pwm: omap-dmtimer: Fix inaccurate period and duty cycle calculations

2016-03-23T16:11:45+00:00

Fix the calculation of load_value and match_value. Currently they
are slightly too low, which produces a noticeably wrong PWM rate with
sufficiently short periods (i.e. when 1/period approaches clk_rate/2).

Example:
 clk_rate=32768Hz, period=122070ns, duty_cycle=61035ns (8192Hz/50% PWM)
 Correct values: load = 0xfffffffc, match = 0xfffffffd
 Current values: load = 0xfffffffa, match = 0xfffffffc
 effective PWM: period=183105ns, duty_cycle=91553ns (5461Hz/50% PWM)

Fixes: 6604c6556db9 ("pwm: Add PWM driver for OMAP using dual-mode timers")
Signed-off-by: David Rivshin 
Acked-by: Neil Armstrong 
Tested-by: Adam Ford 
Signed-off-by: Thierry Reding

pwm: brcmstb: Fix check of devm_ioremap_resource() return code

2016-03-23T16:11:45+00:00

The change fixes potential oops while accessing iomem on invalid address
if devm_ioremap_resource() fails due to some reason.

The devm_ioremap_resource() function returns ERR_PTR() and never returns
NULL, which makes useless a following check for NULL.

Signed-off-by: Vladimir Zapolskiy 
Fixes: 3a9f5957020f ("pwm: Add Broadcom BCM7038 PWM controller support")
Acked-by: Florian Fainelli 
Signed-off-by: Thierry Reding

pwm: rcar: Depend on ARCH_RENESAS instead of ARCH_SHMOBILE

2016-03-23T16:11:44+00:00

This is part of an ongoing process to migrate from ARCH_SHMOBILE to
ARCH_RENESAS the motivation for which being that RENESAS seems to be a
more appropriate name than SHMOBILE for the majority of Renesas ARM
based SoCs.

Signed-off-by: Simon Horman 
Acked-by: Geert Uytterhoeven 
Signed-off-by: Thierry Reding

pwm: lpc18xx-sct: Test clock rate to avoid division by 0

2016-03-23T16:11:29+00:00

The clk API may return 0 on clk_get_rate(), so we should check the
result before using it as a divisor.

Signed-off-by: Wolfram Sang 
Acked-by: Joachim Eastwood 
Signed-off-by: Thierry Reding

pwm: img: Test clock rate to avoid division by 0

2016-03-23T16:11:02+00:00

The clk API may return 0 on clk_get_rate(), so we should check the
result before using it as a divisor.

Signed-off-by: Wolfram Sang 
Signed-off-by: Thierry Reding

pwm: Mark all devices as "might sleep"

2016-01-21T14:04:59+00:00

Commit d1cd21427747 ("pwm: Set enable state properly on failed call to
enable") introduced a mutex that is needed to protect internal state of
PWM devices. Since that mutex is acquired in pwm_set_polarity() and in
pwm_enable() and might potentially block, all PWM devices effectively
become "might sleep".

It's rather pointless to keep the .can_sleep field around, but given
that there are external users let's postpone the removal for the next
release cycle.

Signed-off-by: Thierry Reding