* [PATCH 0/2] pwm: vt8500: Implement .apply() callback
@ 2021-11-02 9:28 ` Uwe Kleine-König
0 siblings, 0 replies; 8+ messages in thread
From: Uwe Kleine-König @ 2021-11-02 9:28 UTC (permalink / raw)
To: Thierry Reding, Lee Jones; +Cc: linux-arm-kernel, linux-pwm, Tony Prisk
Hello,
this series implements .apply for the vt8500 pwm driver and fixes a
function name that I stumbled over while doing that.
One thing that could be improved (but probably only with hardware
available which I don't have) is:
- vt8500_pwm_apply() calls the old callbacks now, it might be possible
to improve clk handling such that the clk is at most once enabled and
once disabled.
- .probe() doesn't handle the PWM already being on.
- There is no .get_state() callback.
Best regards
Uwe
Uwe Kleine-König (2):
pwm: vt8500: Implement .apply() callback
pwm: vt8500: Rename pwm_busy_wait() to make it obviously
driver-specific
drivers/pwm/pwm-vt8500.c | 73 +++++++++++++++++++++++++++++++---------
1 file changed, 58 insertions(+), 15 deletions(-)
base-commit: 8bb7eca972ad531c9b149c0a51ab43a417385813
--
2.30.2
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH 0/2] pwm: vt8500: Implement .apply() callback
@ 2021-11-02 9:28 ` Uwe Kleine-König
0 siblings, 0 replies; 8+ messages in thread
From: Uwe Kleine-König @ 2021-11-02 9:28 UTC (permalink / raw)
To: Thierry Reding, Lee Jones; +Cc: linux-arm-kernel, linux-pwm, Tony Prisk
Hello,
this series implements .apply for the vt8500 pwm driver and fixes a
function name that I stumbled over while doing that.
One thing that could be improved (but probably only with hardware
available which I don't have) is:
- vt8500_pwm_apply() calls the old callbacks now, it might be possible
to improve clk handling such that the clk is at most once enabled and
once disabled.
- .probe() doesn't handle the PWM already being on.
- There is no .get_state() callback.
Best regards
Uwe
Uwe Kleine-König (2):
pwm: vt8500: Implement .apply() callback
pwm: vt8500: Rename pwm_busy_wait() to make it obviously
driver-specific
drivers/pwm/pwm-vt8500.c | 73 +++++++++++++++++++++++++++++++---------
1 file changed, 58 insertions(+), 15 deletions(-)
base-commit: 8bb7eca972ad531c9b149c0a51ab43a417385813
--
2.30.2
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH 1/2] pwm: vt8500: Implement .apply() callback
2021-11-02 9:28 ` Uwe Kleine-König
@ 2021-11-02 9:28 ` Uwe Kleine-König
-1 siblings, 0 replies; 8+ messages in thread
From: Uwe Kleine-König @ 2021-11-02 9:28 UTC (permalink / raw)
To: Thierry Reding, Lee Jones; +Cc: linux-arm-kernel, linux-pwm, Tony Prisk
To eventually get rid of all legacy drivers convert this driver to the
modern world implementing .apply(). This just pushes down a slightly
optimized variant of how legacy drivers are handled in the core.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
drivers/pwm/pwm-vt8500.c | 57 +++++++++++++++++++++++++++++++++++-----
1 file changed, 50 insertions(+), 7 deletions(-)
diff --git a/drivers/pwm/pwm-vt8500.c b/drivers/pwm/pwm-vt8500.c
index ea2aa151080a..3203ec1b0d24 100644
--- a/drivers/pwm/pwm-vt8500.c
+++ b/drivers/pwm/pwm-vt8500.c
@@ -70,7 +70,7 @@ static inline void pwm_busy_wait(struct vt8500_chip *vt8500, int nr, u8 bitmask)
}
static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
- int duty_ns, int period_ns)
+ u64 duty_ns, u64 period_ns)
{
struct vt8500_chip *vt8500 = to_vt8500_chip(chip);
unsigned long long c;
@@ -102,8 +102,8 @@ static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
}
c = (unsigned long long)pv * duty_ns;
- do_div(c, period_ns);
- dc = c;
+
+ dc = div64_u64(c, period_ns);
writel(prescale, vt8500->base + REG_SCALAR(pwm->hwpwm));
pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_SCALAR_UPDATE);
@@ -176,11 +176,54 @@ static int vt8500_pwm_set_polarity(struct pwm_chip *chip,
return 0;
}
+static int vt8500_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ int err;
+ bool enabled = pwm->state.enabled;
+
+ if (state->polarity != pwm->state.polarity) {
+ /*
+ * Changing the polarity of a running PWM is only allowed when
+ * the PWM driver implements ->apply().
+ */
+ if (enabled) {
+ vt8500_pwm_disable(chip, pwm);
+
+ enabled = false;
+ }
+
+ err = vt8500_pwm_set_polarity(chip, pwm, state->polarity);
+ if (err)
+ return err;
+ }
+
+ if (!state->enabled) {
+ if (enabled)
+ vt8500_pwm_disable(chip, pwm);
+
+ return 0;
+ }
+
+ /*
+ * We cannot skip calling ->config even if state->period ==
+ * pwm->state.period && state->duty_cycle == pwm->state.duty_cycle
+ * because we might have exited early in the last call to
+ * pwm_apply_state because of !state->enabled and so the two values in
+ * pwm->state might not be configured in hardware.
+ */
+ err = vt8500_pwm_config(pwm->chip, pwm, state->duty_cycle, state->period);
+ if (err)
+ return err;
+
+ if (!enabled)
+ err = vt8500_pwm_enable(chip, pwm);
+
+ return err;
+}
+
static const struct pwm_ops vt8500_pwm_ops = {
- .enable = vt8500_pwm_enable,
- .disable = vt8500_pwm_disable,
- .config = vt8500_pwm_config,
- .set_polarity = vt8500_pwm_set_polarity,
+ .apply = vt8500_pwm_apply,
.owner = THIS_MODULE,
};
--
2.30.2
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH 1/2] pwm: vt8500: Implement .apply() callback
@ 2021-11-02 9:28 ` Uwe Kleine-König
0 siblings, 0 replies; 8+ messages in thread
From: Uwe Kleine-König @ 2021-11-02 9:28 UTC (permalink / raw)
To: Thierry Reding, Lee Jones; +Cc: linux-arm-kernel, linux-pwm, Tony Prisk
To eventually get rid of all legacy drivers convert this driver to the
modern world implementing .apply(). This just pushes down a slightly
optimized variant of how legacy drivers are handled in the core.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
drivers/pwm/pwm-vt8500.c | 57 +++++++++++++++++++++++++++++++++++-----
1 file changed, 50 insertions(+), 7 deletions(-)
diff --git a/drivers/pwm/pwm-vt8500.c b/drivers/pwm/pwm-vt8500.c
index ea2aa151080a..3203ec1b0d24 100644
--- a/drivers/pwm/pwm-vt8500.c
+++ b/drivers/pwm/pwm-vt8500.c
@@ -70,7 +70,7 @@ static inline void pwm_busy_wait(struct vt8500_chip *vt8500, int nr, u8 bitmask)
}
static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
- int duty_ns, int period_ns)
+ u64 duty_ns, u64 period_ns)
{
struct vt8500_chip *vt8500 = to_vt8500_chip(chip);
unsigned long long c;
@@ -102,8 +102,8 @@ static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
}
c = (unsigned long long)pv * duty_ns;
- do_div(c, period_ns);
- dc = c;
+
+ dc = div64_u64(c, period_ns);
writel(prescale, vt8500->base + REG_SCALAR(pwm->hwpwm));
pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_SCALAR_UPDATE);
@@ -176,11 +176,54 @@ static int vt8500_pwm_set_polarity(struct pwm_chip *chip,
return 0;
}
+static int vt8500_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ int err;
+ bool enabled = pwm->state.enabled;
+
+ if (state->polarity != pwm->state.polarity) {
+ /*
+ * Changing the polarity of a running PWM is only allowed when
+ * the PWM driver implements ->apply().
+ */
+ if (enabled) {
+ vt8500_pwm_disable(chip, pwm);
+
+ enabled = false;
+ }
+
+ err = vt8500_pwm_set_polarity(chip, pwm, state->polarity);
+ if (err)
+ return err;
+ }
+
+ if (!state->enabled) {
+ if (enabled)
+ vt8500_pwm_disable(chip, pwm);
+
+ return 0;
+ }
+
+ /*
+ * We cannot skip calling ->config even if state->period ==
+ * pwm->state.period && state->duty_cycle == pwm->state.duty_cycle
+ * because we might have exited early in the last call to
+ * pwm_apply_state because of !state->enabled and so the two values in
+ * pwm->state might not be configured in hardware.
+ */
+ err = vt8500_pwm_config(pwm->chip, pwm, state->duty_cycle, state->period);
+ if (err)
+ return err;
+
+ if (!enabled)
+ err = vt8500_pwm_enable(chip, pwm);
+
+ return err;
+}
+
static const struct pwm_ops vt8500_pwm_ops = {
- .enable = vt8500_pwm_enable,
- .disable = vt8500_pwm_disable,
- .config = vt8500_pwm_config,
- .set_polarity = vt8500_pwm_set_polarity,
+ .apply = vt8500_pwm_apply,
.owner = THIS_MODULE,
};
--
2.30.2
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH 2/2] pwm: vt8500: Rename pwm_busy_wait() to make it obviously driver-specific
2021-11-02 9:28 ` Uwe Kleine-König
@ 2021-11-02 9:28 ` Uwe Kleine-König
-1 siblings, 0 replies; 8+ messages in thread
From: Uwe Kleine-König @ 2021-11-02 9:28 UTC (permalink / raw)
To: Thierry Reding, Lee Jones; +Cc: linux-arm-kernel, linux-pwm, Tony Prisk
The pwm_ prefix suggests that pwm_busy_wait() is a function provided by
the pwm core. Use the otherwise consistently used driver prefix for this
function, too.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
drivers/pwm/pwm-vt8500.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/drivers/pwm/pwm-vt8500.c b/drivers/pwm/pwm-vt8500.c
index 3203ec1b0d24..7170a315535b 100644
--- a/drivers/pwm/pwm-vt8500.c
+++ b/drivers/pwm/pwm-vt8500.c
@@ -56,7 +56,7 @@ struct vt8500_chip {
#define to_vt8500_chip(chip) container_of(chip, struct vt8500_chip, chip)
#define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)
-static inline void pwm_busy_wait(struct vt8500_chip *vt8500, int nr, u8 bitmask)
+static inline void vt8500_pwm_busy_wait(struct vt8500_chip *vt8500, int nr, u8 bitmask)
{
int loops = msecs_to_loops(10);
u32 mask = bitmask << (nr << 8);
@@ -106,18 +106,18 @@ static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
dc = div64_u64(c, period_ns);
writel(prescale, vt8500->base + REG_SCALAR(pwm->hwpwm));
- pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_SCALAR_UPDATE);
+ vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_SCALAR_UPDATE);
writel(pv, vt8500->base + REG_PERIOD(pwm->hwpwm));
- pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_PERIOD_UPDATE);
+ vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_PERIOD_UPDATE);
writel(dc, vt8500->base + REG_DUTY(pwm->hwpwm));
- pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_DUTY_UPDATE);
+ vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_DUTY_UPDATE);
val = readl(vt8500->base + REG_CTRL(pwm->hwpwm));
val |= CTRL_AUTOLOAD;
writel(val, vt8500->base + REG_CTRL(pwm->hwpwm));
- pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
+ vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
clk_disable(vt8500->clk);
return 0;
@@ -138,7 +138,7 @@ static int vt8500_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
val = readl(vt8500->base + REG_CTRL(pwm->hwpwm));
val |= CTRL_ENABLE;
writel(val, vt8500->base + REG_CTRL(pwm->hwpwm));
- pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
+ vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
return 0;
}
@@ -151,7 +151,7 @@ static void vt8500_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
val = readl(vt8500->base + REG_CTRL(pwm->hwpwm));
val &= ~CTRL_ENABLE;
writel(val, vt8500->base + REG_CTRL(pwm->hwpwm));
- pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
+ vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
clk_disable(vt8500->clk);
}
@@ -171,7 +171,7 @@ static int vt8500_pwm_set_polarity(struct pwm_chip *chip,
val &= ~CTRL_INVERT;
writel(val, vt8500->base + REG_CTRL(pwm->hwpwm));
- pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
+ vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
return 0;
}
--
2.30.2
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH 2/2] pwm: vt8500: Rename pwm_busy_wait() to make it obviously driver-specific
@ 2021-11-02 9:28 ` Uwe Kleine-König
0 siblings, 0 replies; 8+ messages in thread
From: Uwe Kleine-König @ 2021-11-02 9:28 UTC (permalink / raw)
To: Thierry Reding, Lee Jones; +Cc: linux-arm-kernel, linux-pwm, Tony Prisk
The pwm_ prefix suggests that pwm_busy_wait() is a function provided by
the pwm core. Use the otherwise consistently used driver prefix for this
function, too.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
drivers/pwm/pwm-vt8500.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/drivers/pwm/pwm-vt8500.c b/drivers/pwm/pwm-vt8500.c
index 3203ec1b0d24..7170a315535b 100644
--- a/drivers/pwm/pwm-vt8500.c
+++ b/drivers/pwm/pwm-vt8500.c
@@ -56,7 +56,7 @@ struct vt8500_chip {
#define to_vt8500_chip(chip) container_of(chip, struct vt8500_chip, chip)
#define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)
-static inline void pwm_busy_wait(struct vt8500_chip *vt8500, int nr, u8 bitmask)
+static inline void vt8500_pwm_busy_wait(struct vt8500_chip *vt8500, int nr, u8 bitmask)
{
int loops = msecs_to_loops(10);
u32 mask = bitmask << (nr << 8);
@@ -106,18 +106,18 @@ static int vt8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
dc = div64_u64(c, period_ns);
writel(prescale, vt8500->base + REG_SCALAR(pwm->hwpwm));
- pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_SCALAR_UPDATE);
+ vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_SCALAR_UPDATE);
writel(pv, vt8500->base + REG_PERIOD(pwm->hwpwm));
- pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_PERIOD_UPDATE);
+ vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_PERIOD_UPDATE);
writel(dc, vt8500->base + REG_DUTY(pwm->hwpwm));
- pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_DUTY_UPDATE);
+ vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_DUTY_UPDATE);
val = readl(vt8500->base + REG_CTRL(pwm->hwpwm));
val |= CTRL_AUTOLOAD;
writel(val, vt8500->base + REG_CTRL(pwm->hwpwm));
- pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
+ vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
clk_disable(vt8500->clk);
return 0;
@@ -138,7 +138,7 @@ static int vt8500_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
val = readl(vt8500->base + REG_CTRL(pwm->hwpwm));
val |= CTRL_ENABLE;
writel(val, vt8500->base + REG_CTRL(pwm->hwpwm));
- pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
+ vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
return 0;
}
@@ -151,7 +151,7 @@ static void vt8500_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
val = readl(vt8500->base + REG_CTRL(pwm->hwpwm));
val &= ~CTRL_ENABLE;
writel(val, vt8500->base + REG_CTRL(pwm->hwpwm));
- pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
+ vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
clk_disable(vt8500->clk);
}
@@ -171,7 +171,7 @@ static int vt8500_pwm_set_polarity(struct pwm_chip *chip,
val &= ~CTRL_INVERT;
writel(val, vt8500->base + REG_CTRL(pwm->hwpwm));
- pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
+ vt8500_pwm_busy_wait(vt8500, pwm->hwpwm, STATUS_CTRL_UPDATE);
return 0;
}
--
2.30.2
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH 1/2] pwm: vt8500: Implement .apply() callback
2021-11-02 9:28 ` Uwe Kleine-König
@ 2021-11-17 16:16 ` Thierry Reding
-1 siblings, 0 replies; 8+ messages in thread
From: Thierry Reding @ 2021-11-17 16:16 UTC (permalink / raw)
To: Uwe Kleine-König; +Cc: Lee Jones, linux-arm-kernel, linux-pwm, Tony Prisk
[-- Attachment #1: Type: text/plain, Size: 521 bytes --]
On Tue, Nov 02, 2021 at 10:28:03AM +0100, Uwe Kleine-König wrote:
> To eventually get rid of all legacy drivers convert this driver to the
> modern world implementing .apply(). This just pushes down a slightly
> optimized variant of how legacy drivers are handled in the core.
>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
> drivers/pwm/pwm-vt8500.c | 57 +++++++++++++++++++++++++++++++++++-----
> 1 file changed, 50 insertions(+), 7 deletions(-)
Applied, thanks.
Thierry
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/2] pwm: vt8500: Implement .apply() callback
@ 2021-11-17 16:16 ` Thierry Reding
0 siblings, 0 replies; 8+ messages in thread
From: Thierry Reding @ 2021-11-17 16:16 UTC (permalink / raw)
To: Uwe Kleine-König; +Cc: Lee Jones, linux-arm-kernel, linux-pwm, Tony Prisk
[-- Attachment #1.1: Type: text/plain, Size: 521 bytes --]
On Tue, Nov 02, 2021 at 10:28:03AM +0100, Uwe Kleine-König wrote:
> To eventually get rid of all legacy drivers convert this driver to the
> modern world implementing .apply(). This just pushes down a slightly
> optimized variant of how legacy drivers are handled in the core.
>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
> drivers/pwm/pwm-vt8500.c | 57 +++++++++++++++++++++++++++++++++++-----
> 1 file changed, 50 insertions(+), 7 deletions(-)
Applied, thanks.
Thierry
[-- Attachment #1.2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]
[-- Attachment #2: Type: text/plain, Size: 176 bytes --]
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2021-11-17 16:18 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-11-02 9:28 [PATCH 0/2] pwm: vt8500: Implement .apply() callback Uwe Kleine-König
2021-11-02 9:28 ` Uwe Kleine-König
2021-11-02 9:28 ` [PATCH 1/2] " Uwe Kleine-König
2021-11-02 9:28 ` Uwe Kleine-König
2021-11-17 16:16 ` Thierry Reding
2021-11-17 16:16 ` Thierry Reding
2021-11-02 9:28 ` [PATCH 2/2] pwm: vt8500: Rename pwm_busy_wait() to make it obviously driver-specific Uwe Kleine-König
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