Commit Graph

19 Commits

Author SHA1 Message Date
Boris Brezillon 5c31252c4a pwm: Add the pwm_is_enabled() helper
Some PWM drivers are testing the PWMF_ENABLED flag. Create a helper
function to hide the logic behind enabled test. This will allow us to
smoothly move from the current approach to an atomic PWM update
approach.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-07-20 09:46:06 +02:00
Gaetan Hug 24ccea1ce6 pwm: mxs: Fix period divider computation
The driver computes which clock divider it sould be using from the
requested period. This computation assumes that the link between the
register value and the actual divider value is raising 2 to the power of
the registry value.

    div = 1 << regvalue

This is true only for the first 5 values out of 8. Next values are 64,
256 and, 1024 - instead of 32, 64, 128.
This affects only the users requesting a period > 0.04369s.

Replace the computation with a look-up table.

Signed-off-by: Gaetan Hug <ghug@induct.be>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-03-11 13:11:16 +01:00
Wolfram Sang f05fae14a1 pwm: drop owner assignment from platform_drivers
A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-10-20 16:21:28 +02:00
Shawn Guo bd9c1b6005 pwm: mxs: set pwm_chip can_sleep flag
The .config() calls clk_get_rate() which might sleep, so we need to set
pwm_chip can_sleep flag.  Otherwise, we see the following warning when
using PWM driven heartbeat led.

WARNING: CPU: 0 PID: 0 at kernel/locking/mutex.c:856 mutex_trylock+0x184/0x1a4()
DEBUG_LOCKS_WARN_ON(in_interrupt())
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 3.14.0-rc5 
[<c0015420>] (unwind_backtrace) from [<c0012cb0>] (show_stack+0x10/0x14)
[<c0012cb0>] (show_stack) from [<c001daf8>] (warn_slowpath_common+0x6c/0x8c)
[<c001daf8>] (warn_slowpath_common) from [<c001dbac>] (warn_slowpath_fmt+0x30/0x40)
[<c001dbac>] (warn_slowpath_fmt) from [<c045df74>] (mutex_trylock+0x184/0x1a4)
[<c045df74>] (mutex_trylock) from [<c0360950>] (clk_prepare_lock+0xc/0xec)
[<c0360950>] (clk_prepare_lock) from [<c0362020>] (clk_get_rate+0xc/0x68)
[<c0362020>] (clk_get_rate) from [<c028d07c>] (mxs_pwm_config+0x20/0x198)
[<c028d07c>] (mxs_pwm_config) from [<c028bde8>] (pwm_config+0x60/0x70)
[<c028bde8>] (pwm_config) from [<c034b61c>] (__led_pwm_set+0x1c/0x3c)
[<c034b61c>] (__led_pwm_set) from [<c034bc3c>] (led_heartbeat_function+0x70/0x110)
[<c034bc3c>] (led_heartbeat_function) from [<c00292f0>] (call_timer_fn+0x7c/0x164)
[<c00292f0>] (call_timer_fn) from [<c00295c8>] (run_timer_softirq+0x1f0/0x260)
[<c00295c8>] (run_timer_softirq) from [<c002255c>] (__do_softirq+0xc4/0x2f0)
[<c002255c>] (__do_softirq) from [<c0022890>] (irq_exit+0xa4/0x10c)
[<c0022890>] (irq_exit) from [<c0010240>] (handle_IRQ+0x34/0x84)
[<c0010240>] (handle_IRQ) from [<c0013524>] (__irq_svc+0x44/0x54)
[<c0013524>] (__irq_svc) from [<c00107f8>] (arch_cpu_idle+0x40/0x48)
[<c00107f8>] (arch_cpu_idle) from [<c005deb8>] (cpu_startup_entry+0x70/0x198)
[<c005deb8>] (cpu_startup_entry) from [<c060aac8>] (start_kernel+0x2a8/0x2f8)

Reported-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-05-21 12:08:27 +02:00
Sachin Kamat de02cb887c pwm: mxs: Remove redundant of_match_ptr
The data structure of_match_ptr() protects is always compiled in.
Hence of_match_ptr() is not needed.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2013-10-08 15:49:10 +02:00
Fabio Estevam cfb9e4c40e pwm: mxs: Check the return value from stmp_reset_block()
stmp_reset_block() may fail, so let's check its return value and
propagate it in the case of error.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2013-09-03 13:07:51 +02:00
Thierry Reding 3dd0a90947 pwm: Fill in missing .owner fields
Some drivers don't set the .owner fields of the struct device_driver or
struct pwm_ops, which causes the module usage count to become wrong.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2013-06-12 13:18:29 +02:00
Fabio Estevam e7927141ed pwm: mxs: Let device core handle pinctrl
Since commit ab78029 (drivers/pinctrl: grab default handles from device core),
we can rely on device core for handling pinctrl.

So remove devm_pinctrl_get_select_default() from the driver.

Cc: Thierry Reding <thierry.reding@avionic-design.de>
Cc: <linux-kernel@vger.kernel.org>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2013-05-27 17:48:33 +02:00
Thierry Reding f1a8870aeb pwm: Constify OF match tables
A few drivers already annotate this properly. Make the same change for
all other OF supporting drivers.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Alexandre Pereira da Silva <aletes.xgr@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2013-04-23 07:42:20 +02:00
Axel Lin 4e61573df8 pwm: mxs: Remove unused *dev from struct mxs_pwm_chip
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2013-04-02 11:33:05 +02:00
Thierry Reding 6d4294d163 pwm: Convert to devm_ioremap_resource()
Convert all uses of devm_request_and_ioremap() to the newly introduced
devm_ioremap_resource() which provides more consistent error handling.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-22 11:41:57 -08:00
Bill Pemberton 77f37917a6 pwm: remove use of __devexit
CONFIG_HOTPLUG is going away as an option so __devexit is no
longer needed.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Acked-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-28 12:23:41 -08:00
Bill Pemberton fd1091125a pwm: remove use of __devexit_p
CONFIG_HOTPLUG is going away as an option so __devexit_p is no longer
needed.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Acked-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-28 12:23:41 -08:00
Axel Lin 457fd768ee pwm: pwm-mxs: Return proper error if pwmchip_remove() fails
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2012-07-23 13:24:01 +02:00
Shawn Guo 1112fe88d4 pwm: pwm-mxs: add pinctrl support
Call pinctrl subsystem to set up pwm pin.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2012-07-23 13:23:56 +02:00
Shawn Guo 22d260bd88 pwm: pwm-mxs: use devm_* managed functions
Use devm_* managed functions to have a clean fail-out.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2012-07-23 13:23:55 +02:00
Shawn Guo 01bf32e949 pwm: pwm-mxs: use global reset function stmp_reset_block
Use global reset function stmp_reset_block instead of mxs_reset_block
to remove <mach/common.h> inclusion.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2012-07-23 13:23:54 +02:00
Shawn Guo 071407eefd pwm: pwm-mxs: encode soc name in compatible string
Encode soc name in the compatible string to know the specific version
hardware block.  This is the general approach adopted for most bindings.
Change mxs-pwm binding to use the approach.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2012-07-23 13:23:53 +02:00
Shawn Guo 4dce82c1e8 pwm: add pwm-mxs support
Add generic PWM framework driver (DT only) for Freescale MXS.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2012-07-02 22:06:34 +02:00