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>

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);

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;

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);

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;

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;

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;