9 Commits

Author SHA1 Message Date
Uwe Kleine-König
6aaac1d924 pwm: sifive: Shut down hardware only after pwmchip_remove() completed
[ Upstream commit 2375e964d541bb09158cd2dff67b5d74e8de61cd ]

The PWMs are expected to be functional until pwmchip_remove() is called.
So disable the clks only afterwards.

Fixes: 9e37a53eb051 ("pwm: sifive: Add a driver for SiFive SoC PWM")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21 15:15:37 +02:00
Uwe Kleine-König
9073dbec88 pwm: sifive: Ensure the clk is enabled exactly once per running PWM
[ Upstream commit ace41d7564e655c39f709a78c035188a460c7cbd ]

.apply() assumes the clk to be for a given PWM iff the PWM is enabled.
So make sure this is the case when .probe() completes. And in .remove()
disable the according number of times.

This fixes a clk enable/disable imbalance, if some PWMs are already running
at probe time.

Fixes: 9e37a53eb051 (pwm: sifive: Add a driver for SiFive SoC PWM)
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21 15:15:37 +02:00
Uwe Kleine-König
47902de24a pwm: sifive: Simplify offset calculation for PWMCMP registers
[ Upstream commit 20550a61880fc55e68a0d290ad195b74729c0e7b ]

Instead of explicitly using PWM_SIFIVE_PWMCMP0 + pwm->hwpwm *
PWM_SIFIVE_SIZE_PWMCMP for each access to one of the PWMCMP registers,
introduce a macro that takes the hwpwm id as parameter.

For the register definition using a plain 4 instead of the cpp constant
PWM_SIFIVE_SIZE_PWMCMP is easier to read, so define the offset macro
without the constant. The latter can then be dropped as there are no
users left.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21 15:15:37 +02:00
Uwe Kleine-König
6d7f7ffbcd pwm: sifive: Don't check the return code of pwmchip_remove()
[ Upstream commit ceb2c2842f3664dcc4e6d8cb317e1e83bb81b1e5 ]

pwmchip_remove() returns always 0. Don't use the value to make it
possible to eventually change the function to return void. Also the
driver core ignores the return value of pwm_sifive_remove().

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-21 15:15:37 +02:00
Krzysztof Kozlowski
5530fcaf9c pwm: sifive: Simplify with dev_err_probe()
Common pattern of handling deferred probe can be simplified with
dev_err_probe().  Less code and also it prints the error value.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-09-24 09:18:11 +02:00
Guru Das Srinagesh
4cc23430a5 pwm: sifive: Use 64-bit division macro
Since the PWM framework is switching struct pwm_args.period's datatype
to u64, prepare for this transition by using DIV64_U64_ROUND_CLOSEST to
handle a 64-bit divisor.

Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-17 20:42:09 +02:00
Uwe Kleine-König
71523d1812 pwm: Ensure pwm_apply_state() doesn't modify the state argument
It is surprising for a PWM consumer when the variable holding the
requested state is modified by pwm_apply_state(). Consider for example a
driver doing:

        #define PERIOD 5000000
        #define DUTY_LITTLE 10
        ...
        struct pwm_state state = {
                .period = PERIOD,
                .duty_cycle = DUTY_LITTLE,
                .polarity = PWM_POLARITY_NORMAL,
                .enabled = true,
        };

        pwm_apply_state(mypwm, &state);
        ...
        state.duty_cycle = PERIOD / 2;
        pwm_apply_state(mypwm, &state);

For sure the second call to pwm_apply_state() should still have
state.period = PERIOD and not something the hardware driver chose for a
reason that doesn't necessarily apply to the second call.

So declare the state argument as a pointer to a const type and adapt all
drivers' .apply callbacks.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21 03:25:10 +02:00
Ding Xiang
f6abac0379 pwm: sifive: Remove redundant error message
devm_ioremap_resource() already outputs an error message, so remove the
extra error message on failure.

Signed-off-by: Ding Xiang <dingxiang@cmss.chinamobile.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21 00:26:16 +02:00
Yash Shah
9e37a53eb0 pwm: sifive: Add a driver for SiFive SoC PWM
Adds a PWM driver for PWM chip present in SiFive's HiFive Unleashed SoC.

Signed-off-by: Wesley W. Terpstra <wesley@sifive.com>
[Atish: Various fixes and code cleanup]
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Yash Shah <yash.shah@sifive.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-25 14:48:12 +02:00