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path: root/drivers/pwm/pwm-omap-dmtimer.c
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2018-08-20pwm: omap-dmtimer: Return -EPROBE_DEFER if no dmtimer platform dataDavid Rivshin1-2/+3
If a pwm-omap-dmtimer is probed before the dmtimer it uses, the platform data won't be set yet. Fixes: ac30751df953 ("ARM: OMAP: pdata-quirks: Remove unused timer pdata") Cc: <stable@vger.kernel.org> # 4.17+ Signed-off-by: David Rivshin <drivshin@allworx.com> Acked-by: Pavel Machek <pavel@ucw.cz> Tested-by: Pavel Machek <pavel@ucw.cz> Acked-by: Ladislav Michl <ladis@linux-mips.org> Tested-by: Andreas Kemnade <andreas@kemnade.info> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-02-22pwm: pwm-omap-dmtimer: Adapt driver to utilize dmtimer pdata opsKeerthy1-26/+42
Adapt driver to utilize dmtimer pdata ops instead of pdata-quirks. Signed-off-by: Keerthy <j-keerthy@ti.com> Acked-by: Neil Armstrong <narmstrong@baylibre.com> Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-29pwm: omap-dmtimer: Allow for setting dmtimer clock sourceIvaylo Dimitrov1-5/+7
OMAP GP timers can have different input clocks that allow different PWM frequencies. However, there is no other way of setting the clock source but through clocks or clock-names properties of the timer itself. This limits PWM functionality to only the frequencies allowed by the particular clock source. Allowing setting the clock source by PWM rather than by timer allows different PWMs to have different ranges by not hard-wiring the clock source to the timer. Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> Acked-by: Rob Herring <robh@kernel.org> Acked-by: Thierry Reding <treding@nvidia.com> Acked-by: Pali Rohár <pali.rohar@gmail.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-05-17pwm: Use pwm_get/set_xxx() helpers where appropriateBoris Brezillon1-1/+1
Use pwm_get/set_xxx() helpers instead of directly accessing the pwm->xxx field. Doing that will ease adaptation of the PWM framework to support atomic update. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-03-23pwm: omap-dmtimer: Add debug message for effective period and duty cycleDavid Rivshin1-1/+8
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 <drivshin@allworx.com> Acked-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-03-23pwm: omap-dmtimer: Round load and match values rather than truncateDavid Rivshin1-5/+1
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 <drivshin@allworx.com> Acked-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-03-23pwm: omap-dmtimer: Add sanity checking for load and match valuesDavid Rivshin1-4/+30
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 <drivshin@allworx.com> Acked-by: Neil Armstrong <narmstrong@baylibre.com> [thierry.reding@gmail.com: minor coding style cleanups] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-03-23pwm: omap-dmtimer: Fix inaccurate period and duty cycle calculationsDavid Rivshin1-7/+20
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 <drivshin@allworx.com> Acked-by: Neil Armstrong <narmstrong@baylibre.com> Tested-by: Adam Ford <aford173@gmail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-01-04pwm: omap-dmtimer: Potential NULL dereference on errorDan Carpenter1-1/+1
"omap" is NULL so we can't dereference it. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-12-16pwm: Add PWM driver for OMAP using dual-mode timersNeil Armstrong1-0/+327
Adds support for using a OMAP dual-mode timer with PWM capability as a Linux PWM device. The driver controls the timer by using the dmtimer API. Add a platform_data structure for each pwm-omap-dmtimer nodes containing the dmtimers functions in order to get driver not rely on platform specific functions. Cc: Grant Erickson <marathon96@gmail.com> Cc: NeilBrown <neilb@suse.de> Cc: Joachim Eastwood <manabian@gmail.com> Suggested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> Acked-by: Tony Lindgren <tony@atomide.com> [thierry.reding@gmail.com: coding style bikeshed, fix timer leak] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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