[PATCH v3 1/2] pwm: Introduce single-PWM of_xlate function

From: Bjorn Andersson
Date: Mon Jun 21 2021 - 23:09:58 EST


The existing pxa driver and the upcoming addition of PWM support in the
TI sn565dsi86 DSI/eDP bridge driver both has a single PWM channel and
thereby a need for a of_xlate function with the period as its single
argument.

Introduce a common helper function in the core that can be used as
of_xlate by such drivers and migrate the pxa driver to use this.

Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
---

Changes since v2:
- None

drivers/pwm/core.c | 26 ++++++++++++++++++++++++++
drivers/pwm/pwm-pxa.c | 16 +---------------
include/linux/pwm.h | 2 ++
3 files changed, 29 insertions(+), 15 deletions(-)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index a42999f877d2..5e9c876fccc4 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -152,6 +152,32 @@ of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
}
EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);

+struct pwm_device *
+of_pwm_single_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
+{
+ struct pwm_device *pwm;
+
+ if (pc->of_pwm_n_cells < 1)
+ return ERR_PTR(-EINVAL);
+
+ /* validate that one cell is specified, optionally with flags */
+ if (args->args_count != 1 && args->args_count != 2)
+ return ERR_PTR(-EINVAL);
+
+ pwm = pwm_request_from_chip(pc, 0, NULL);
+ if (IS_ERR(pwm))
+ return pwm;
+
+ pwm->args.period = args->args[0];
+ pwm->args.polarity = PWM_POLARITY_NORMAL;
+
+ if (args->args_count == 2 && args->args[2] & PWM_POLARITY_INVERTED)
+ pwm->args.polarity = PWM_POLARITY_INVERSED;
+
+ return pwm;
+}
+EXPORT_SYMBOL_GPL(of_pwm_single_xlate);
+
static void of_pwmchip_add(struct pwm_chip *chip)
{
if (!chip->dev || !chip->dev->of_node)
diff --git a/drivers/pwm/pwm-pxa.c b/drivers/pwm/pwm-pxa.c
index cfb683827d32..8cd82fb54483 100644
--- a/drivers/pwm/pwm-pxa.c
+++ b/drivers/pwm/pwm-pxa.c
@@ -148,20 +148,6 @@ static const struct platform_device_id *pxa_pwm_get_id_dt(struct device *dev)
return id ? id->data : NULL;
}

-static struct pwm_device *
-pxa_pwm_of_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
-{
- struct pwm_device *pwm;
-
- pwm = pwm_request_from_chip(pc, 0, NULL);
- if (IS_ERR(pwm))
- return pwm;
-
- pwm->args.period = args->args[0];
-
- return pwm;
-}
-
static int pwm_probe(struct platform_device *pdev)
{
const struct platform_device_id *id = platform_get_device_id(pdev);
@@ -187,7 +173,7 @@ static int pwm_probe(struct platform_device *pdev)
pwm->chip.npwm = (id->driver_data & HAS_SECONDARY_PWM) ? 2 : 1;

if (IS_ENABLED(CONFIG_OF)) {
- pwm->chip.of_xlate = pxa_pwm_of_xlate;
+ pwm->chip.of_xlate = of_pwm_single_xlate;
pwm->chip.of_pwm_n_cells = 1;
}

diff --git a/include/linux/pwm.h b/include/linux/pwm.h
index 5a73251d28e3..6aff1fa4fe5d 100644
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -411,6 +411,8 @@ struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip,

struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc,
const struct of_phandle_args *args);
+struct pwm_device *of_pwm_single_xlate(struct pwm_chip *pc,
+ const struct of_phandle_args *args);

struct pwm_device *pwm_get(struct device *dev, const char *con_id);
struct pwm_device *of_pwm_get(struct device *dev, struct device_node *np,
--
2.31.0