Commit Graph

15 Commits

Author SHA1 Message Date
David Wu 3f9a363133 pwm: rockchip: Add rk3328 support
The rk3328 SoC supports atomic update, we could lock the configuration
of period and duty at first, after unlock is configured, the period and
duty are effective at the same time.

If the polarity, period and duty need to be configured together,
the way for atomic update is "configure lock and old polarity" ->
"configure period and duty" -> "configure unlock and new polarity".

Signed-off-by: David Wu <david.wu@rock-chips.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-08-18 17:44:34 +02:00
David Wu 831b279050 pwm: rockchip: Use same PWM ops for each IP
Just use the same PWM ops for each IP, and get rid of the ops in struct
rockchip_pwm_data, but still define the three different instances of the
struct to use common interface for each IP.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-08-18 17:42:30 +02:00
David Wu bc834d7b07 pwm: rockchip: Move the configuration of polarity
It is usually possible to configure the polarity, cycle and duty all at
once, so that the polarity and cycle and duty are applied atomically.
Move it from rockchip_pwm_set_enable() into rockchip_pwm_config(), as
well as prepare for the next atomic update commit.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-08-18 17:40:05 +02:00
David Wu ed054693d7 pwm: rockchip: Use pwm_apply() instead of pwm_enable()
Drop the custom hook of pwm_enable() and implement pwm_apply_v1() and
pwm_apply_v2() instead.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-08-18 17:36:56 +02:00
David Wu f90df9cda6 pwm: rockchip: Remove the judge from return value of pwm_config()
It seems the rockchip_pwm_config() always returns the result 0, so
remove the judge.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-08-18 17:33:07 +02:00
David Wu 27922ff598 pwm: rockchip: Add APB and function both clocks support
New PWM module provides two individual clocks for APB clock and function
clock.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-08-18 17:31:56 +02:00
David Wu a900152b5c pwm: rockchip: State of PWM clock should synchronize with PWM enabled state
If the PWM was not enabled at U-Boot loader, PWM could not work for
clock always disabled at PWM driver. The PWM clock is enabled at
beginning of pwm_apply(), but disabled at end of pwm_apply().

If the PWM was enabled at U-Boot loader, PWM clock is always enabled
unless closed by ATF. The pwm-backlight might turn off the power at
early suspend, should disable PWM clock for saving power consume.

It is important to provide opportunity to enable/disable clock at PWM
driver, the PWM consumer should ensure correct order to call PWM enable
and disable, and PWM driver ensure state of PWM clock synchronized with
PWM enabled state.

Fixes: 2bf1c98aa5 ("pwm: rockchip: Add support for atomic update")
Cc: stable@vger.kernel.org
Signed-off-by: David Wu <david.wu@rock-chips.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-04-06 15:08:52 +02:00
Boris Brezillon 2bf1c98aa5 pwm: rockchip: Add support for atomic update
Implement the ->apply() function to add support for atomic update.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Tested-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-07-11 12:49:28 +02:00
Boris Brezillon 48cf973cae pwm: rockchip: Avoid glitches on already running PWMs
The current logic will disable the PWM clk even if the PWM was left
enabled by the bootloader (because it's controlling a critical device
like a regulator for example).
Keep the PWM clk enabled if the PWM is enabled to avoid any glitches.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Tested-by: Brian Norris <briannorris@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-07-11 12:49:27 +02:00
Boris Brezillon 1ebb74cf35 pwm: rockchip: Add support for hardware readout
Implement the ->get_state() function to expose initial state.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Tested-by: Brian Norris <briannorris@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-07-11 12:49:27 +02:00
Boris Brezillon 12f9ce4a51 pwm: rockchip: Fix period and duty cycle approximation
The current implementation always round down the duty and period values,
while it would be better to round them to the closest integer.

These changes are needed in preparation of atomic update support to
prevent a period/duty cycle drift when executing several times the
'pwm_get_state() / modify / pwm_apply_state()' sequence.

Say you have an expected period of 3.333 us and a clk rate of
112.666667 MHz -- the clock frequency doesn't divide evenly, so the
period (stashed in nanoseconds) shrinks when we convert to the register
value and back, as follows:

  pwm_apply_state(): register = period * 112666667 / 1000000000;
  pwm_get_state(): period = register * 1000000000 / 112666667;

or in other words:

  period = period * 112666667 / 1000000000 * 1000000000 / 112666667;

which yields a sequence like:

  3333 -> 3328
  3328 -> 3319
  3319 -> 3310
  3310 -> 3301
  3301 -> 3292
  3292 -> ... (etc) ...

With this patch, we'd see instead:

  period = div_round_closest(period * 112666667, 1000000000) *
                   1000000000 / 112666667;

which yields a stable sequence:

  3333 -> 3337
  3337 -> 3337
  3337 -> ... (etc) ...

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Tested-by: Brian Norris <briannorris@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-07-11 12:49:26 +02:00
Boris Brezillon 15da7b5001 pwm: Make use of pwm_get_xxx() helpers where appropriate
Use the pwm_get_xxx() helpers instead of directly accessing the fields
in struct pwm_device. This will allow us to smoothly move to the atomic
update approach.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-07-20 09:53:22 +02:00
Doug Anderson 7264354c0c 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>
2014-08-26 10:44:08 +02:00
Caesar Wang f630629908 pwm: rockchip: Added to support for RK3288 SoC
This patch added to support the PWM controller found on
RK3288 SoC.

Signed-off-by: Caesar Wang <caesar.wang@rock-chips.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-08-08 13:12:47 +02:00
Beniamino Galvani 101353c82a pwm: add Rockchip SoC PWM support
This commit adds a driver for the PWM controller found on Rockchip
RK29, RK30 and RK31 SoCs.

Signed-off-by: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-07-11 15:54:51 +02:00