Commit Graph

9 Commits

Author SHA1 Message Date
Sean Wang 04c0a4e00d pwm: mediatek: Improve precision in rate calculation
Add a way that turning resolution from in nanosecond into in picosecond
to improve noticeably almost 4.5% precision.

It's necessary to hold the new resolution with type u64 and thus related
operations on u64 are applied instead in those rate calculations.

And the patch has a dependency on [1].

[1] http://lists.infradead.org/pipermail/linux-mediatek/2018-March/012225.html

Cc: stable@vger.kernel.org
Fixes: caf065f8fd ("pwm: Add MediaTek PWM support")
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-03-28 00:32:25 +02:00
Sean Wang f361787636 pwm: mediatek: Remove redundant MODULE_ALIAS entries
MODULE_ALIAS exports information to allow the module to be auto-loaded at
boot for the drivers registered using legacy platform registration.

However, currently the driver is always used by DT-only platform,
MODULE_ALIAS is redundant and should be removed properly.

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-03-28 00:31:59 +02:00
Sean Wang 360cc03656 pwm: mediatek: Fix up PWM4 and PWM5 malfunction on MT7623
Since the offset for both registers, PWMDWIDTH and PWMTHRES, used to
control PWM4 or PWM5 are distinct from the other PWMs, whose wrong
programming on PWM hardware causes waveform cannot be output as expected.
Thus, the patch adds the extra condition for fixing up the weird case to
let PWM4 or PWM5 able to work on MT7623.

v1 -> v2: use pwm45_fixup naming instead of pwm45_quirk
v2 -> v3: add more tags for Reviewed-by, Fixes, and Cc stable

Cc: stable@vger.kernel.org
Fixes: caf065f8fd ("pwm: Add MediaTek PWM support")
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Zhi Mao <zhi.mao@mediatek.com>
Cc: John Crispin <john@phrozen.org>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-03-28 00:29:58 +02:00
Zhi Mao 424268c749 pwm: mediatek: Add MT2712/MT7622 support
Add support for MT2712 and MT7622. Due to register offset address of
pwm7 for MT2712 is not fixed 0x40, add mtk_pwm_reg_offset array for PWM
register offset.

Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Zhi Mao <zhi.mao@mediatek.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-11-15 10:57:53 +01:00
Zhi Mao 8bdb65dc85 pwm: mediatek: Disable clock on PWM configuration failure
Make sure to disable the PWM clock if the PWM cannot be configured due
to the clock divider exceeding the maximum value.

While at it, replace the hardcoded maximum clock divider with a defined
constant to improve code readability.

Signed-off-by: Zhi Mao <zhi.mao@mediatek.com>
Acked-by: John Crispin <john@phrozen.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-08-21 10:39:11 +02:00
Zhi Mao e7c197ec97 pwm: mediatek: Fix clock control issue
In order to save some power, do not prepare the top and main clocks
during mtk_pwm_probe(). Instead, prepare the clocks only when necessary
and also make sure to enable the clocks to match the semantics of the
common clock framework.

While at it, don't explicitly disable all PWM channels in ->remove()
because all users should have done that already.

Signed-off-by: Zhi Mao <zhi.mao@mediatek.com>
Acked-by: John Crispin <john@phrozen.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-08-21 10:39:09 +02:00
Zhi Mao cd30798a6c pwm: mediatek: Fix PWM source clock selection
In original code, the PWM output frequency is not correct when set
bit<3>=1 to PWMCON register.

Signed-off-by: Zhi Mao <zhi.mao@mediatek.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Acked-by: John Crispin <john@phrozen.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-08-21 10:39:09 +02:00
kbuild test robot 6db249db5e pwm: mediatek: Don't explicitly set .owner
drivers/pwm/pwm-mediatek.c:210:3-8: No need to set .owner here. The core will do it.

 Remove .owner field if calls are used which set it automatically

Generated by: scripts/coccinelle/api/platform_no_drv_owner.cocci

CC: John Crispin <john@phrozen.org>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-04-13 17:35:00 +02:00
John Crispin caf065f8fd pwm: Add MediaTek PWM support
This patch adds support for the PWM core found on current ARM base SoCs
made by MediaTek. This IP core supports 5 channels and has 2 operational
modes. There is the old mode, which is a classical PWM and the new mode
which allows the user to define bitmasks that get clocked out on the
pins. As the subsystem currently only supports PWM cores with the "old"
mode, we can safely ignore the "new" mode for now.

Signed-off-by: John Crispin <john@phrozen.org>
[thierry.reding@gmail.com: minor cleanups]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-04-06 17:45:04 +02:00