[RFC v4 09/10] pwm: dwc: add snps,pwm-number to limit pwm count

[Ben Dooks <ben.dooks@sifive.com>]

Add snps,pwm-number property to indicate if the block does not have
all 8 of the PWM blocks.

Not sure if this should be a general PWM property consider optional
for all PWM types, so have added a specific one here (there is only
one other controller with a property for PWM count at the moment)

Signed-off-by: Ben Dooks <ben.dooks@sifive.com>
---
 drivers/pwm/pwm-dwc-of.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/pwm/pwm-dwc-of.c b/drivers/pwm/pwm-dwc-of.c
index d18fac287325..65c7e6621bba 100644
--- a/drivers/pwm/pwm-dwc-of.c
+++ b/drivers/pwm/pwm-dwc-of.c
@@ -21,12 +21,20 @@ static int dwc_pwm_plat_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct dwc_pwm *dwc;
+	u32 nr_pwm;
 	int ret;
 
 	dwc = dwc_pwm_alloc(dev);
 	if (!dwc)
 		return -ENOMEM;
 
+	if (!device_property_read_u32(dev, "snps,pwm-number", &nr_pwm)) {
+		if (nr_pwm > DWC_TIMERS_TOTAL)
+			dev_err(dev, "too many PWMs specified (%d)\n", nr_pwm);
+		else
+			dwc->chip.npwm = nr_pwm;
+	}
+
 	dwc->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(dwc->base))
 		return dev_err_probe(dev, PTR_ERR(dwc->base),
-- 
2.35.1