[PATCH v6 159/164] staging: greybus: pwm: Rework how the number of PWM lines is determined

Uwe Kleine-König
2024-02-14T09:52:36Z

With a later patch it becomes necessary to already now the number of PWM
lines when pwmc is allocated. So make the function not use pwmc but a
plain connection and return the number of lines instead of storing it in
pwmc. This allows to get rid of the pwm_max member.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
drivers/staging/greybus/pwm.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/drivers/staging/greybus/pwm.c b/drivers/staging/greybus/pwm.c
index c7a2e874a62b..35e98e7c00c1 100644
--- a/drivers/staging/greybus/pwm.c
+++ b/drivers/staging/greybus/pwm.c
@@ -16,8 +16,6 @@

struct gb_pwm_chip {
struct gb_connection *connection;
- u8 pwm_max; /* max pwm number */
-
struct pwm_chip chip;
};

@@ -26,17 +24,21 @@ static inline struct gb_pwm_chip *pwm_chip_to_gb_pwm_chip(struct pwm_chip *chip)
return container_of(chip, struct gb_pwm_chip, chip);
}

-static int gb_pwm_count_operation(struct gb_pwm_chip *pwmc)
+static int gb_pwm_get_npwm(struct gb_connection *connection)
{
struct gb_pwm_count_response response;
int ret;

- ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_PWM_COUNT,
+ ret = gb_operation_sync(connection, GB_PWM_TYPE_PWM_COUNT,
NULL, 0, &response, sizeof(response));
if (ret)
return ret;
- pwmc->pwm_max = response.count;
- return 0;
+
+ /*
+ * The request returns the highest allowed PWM id parameter. So add one
+ * to get the number of PWMs.
+ */
+ return response.count + 1;
}

static int gb_pwm_activate_operation(struct pwm_chip *chip, u8 which)
@@ -245,7 +247,7 @@ static int gb_pwm_probe(struct gbphy_device *gbphy_dev,
struct gb_connection *connection;
struct gb_pwm_chip *pwmc;
struct pwm_chip *chip;
- int ret;
+ int ret, npwm;

pwmc = kzalloc(sizeof(*pwmc), GFP_KERNEL);
if (!pwmc)
@@ -267,15 +269,16 @@ static int gb_pwm_probe(struct gbphy_device *gbphy_dev,
goto exit_connection_destroy;

/* Query number of pwms present */
- ret = gb_pwm_count_operation(pwmc);
- if (ret)
+ ret = gb_pwm_get_npwm(connection);
+ if (ret < 0)
goto exit_connection_disable;
+ npwm = ret;

chip = &pwmc->chip;

chip->dev = &gbphy_dev->dev;
chip->ops = &gb_pwm_ops;
- chip->npwm = pwmc->pwm_max + 1;
+ chip->npwm = npwm;

ret = pwmchip_add(chip);
if (ret) {
--
2.43.0