pwm: Check for negative duty-cycle and period

Make sure the duty-cycle and period passed in are not negative. This
should eventually be made implicit by making them unsigned. While at
it, the drivers' .config() implementations can have the equivalent
checks removed.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Axel Lin <axel.lin@gmail.com>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Jingoo Han <jg1.han@samsung.com>
Cc: Jonghwan Choi <jhbird.choi@samsung.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: "Philip, Avinash" <avinashphilip@ti.com>
Cc: Vaibhav Bedia <vaibhav.bedia@ti.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>

6 files changed, 3 insertions, 12 deletions

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 92b1782d0d8..f5acdaa5270 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -371,7 +371,7 @@ EXPORT_SYMBOL_GPL(pwm_free);
  */
 int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
 {
-	if (!pwm || period_ns == 0 || duty_ns > period_ns)
+	if (!pwm || duty_ns < 0 || period_ns <= 0 || duty_ns > period_ns)
 		return -EINVAL;
 
 	return pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns);
diff --git a/drivers/pwm/pwm-bfin.c b/drivers/pwm/pwm-bfin.c
index d53c4e7941e..5da8e185e83 100644
--- a/drivers/pwm/pwm-bfin.c
+++ b/drivers/pwm/pwm-bfin.c
@@ -69,9 +69,6 @@ static int bfin_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	unsigned long period, duty;
 	unsigned long long val;
 
-	if (duty_ns < 0 || duty_ns > period_ns)
-		return -EINVAL;
-
 	val = (unsigned long long)get_sclk() * period_ns;
 	do_div(val, NSEC_PER_SEC);
 	period = val;
diff --git a/drivers/pwm/pwm-pxa.c b/drivers/pwm/pwm-pxa.c
index bd5867a1c70..260c3a88564 100644
--- a/drivers/pwm/pwm-pxa.c
+++ b/drivers/pwm/pwm-pxa.c
@@ -70,9 +70,6 @@ static int pxa_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	unsigned long offset;
 	int rc;
 
-	if (period_ns == 0 || duty_ns > period_ns)
-		return -EINVAL;
-
 	offset = pwm->hwpwm ? 0x10 : 0;
 
 	c = clk_get_rate(pc->clk);
diff --git a/drivers/pwm/pwm-samsung.c b/drivers/pwm/pwm-samsung.c
index e5187c0ade9..023a3bee76e 100644
--- a/drivers/pwm/pwm-samsung.c
+++ b/drivers/pwm/pwm-samsung.c
@@ -126,9 +126,6 @@ static int s3c_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	if (period_ns > NS_IN_HZ || duty_ns > NS_IN_HZ)
 		return -ERANGE;
 
-	if (duty_ns > period_ns)
-		return -EINVAL;
-
 	if (period_ns == s3c->period_ns &&
 	    duty_ns == s3c->duty_ns)
 		return 0;
diff --git a/drivers/pwm/pwm-tiecap.c b/drivers/pwm/pwm-tiecap.c
index 081471fbb09..d6d4cf05565 100644
--- a/drivers/pwm/pwm-tiecap.c
+++ b/drivers/pwm/pwm-tiecap.c
@@ -60,7 +60,7 @@ static int ecap_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	unsigned long period_cycles, duty_cycles;
 	unsigned int reg_val;
 
-	if (period_ns < 0 || duty_ns < 0 || period_ns > NSEC_PER_SEC)
+	if (period_ns > NSEC_PER_SEC)
 		return -ERANGE;
 
 	c = pc->clk_rate;
diff --git a/drivers/pwm/pwm-tiehrpwm.c b/drivers/pwm/pwm-tiehrpwm.c
index caf00feadc6..d3c1dff0a0d 100644
--- a/drivers/pwm/pwm-tiehrpwm.c
+++ b/drivers/pwm/pwm-tiehrpwm.c
@@ -221,7 +221,7 @@ static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	unsigned short ps_divval, tb_divval;
 	int i, cmp_reg;
 
-	if (period_ns < 0 || duty_ns < 0 || period_ns > NSEC_PER_SEC)
+	if (period_ns > NSEC_PER_SEC)
 		return -ERANGE;
 
 	c = pc->clk_rate;