--- zzzz-none-000/linux-3.10.107/drivers/pwm/pwm-lpc32xx.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/pwm/pwm-lpc32xx.c	2021-02-04 17:41:59.000000000 +0000
@@ -24,9 +24,7 @@
 	void __iomem *base;
 };
 
-#define PWM_ENABLE	(1 << 31)
-#define PWM_RELOADV(x)	(((x) & 0xFF) << 8)
-#define PWM_DUTY(x)	((x) & 0xFF)
+#define PWM_ENABLE	BIT(31)
 
 #define to_lpc32xx_pwm_chip(_chip) \
 	container_of(_chip, struct lpc32xx_pwm_chip, chip)
@@ -38,40 +36,27 @@
 	unsigned long long c;
 	int period_cycles, duty_cycles;
 	u32 val;
+	c = clk_get_rate(lpc32xx->clk);
 
-	c = clk_get_rate(lpc32xx->clk) / 256;
-	c = c * period_ns;
-	do_div(c, NSEC_PER_SEC);
-
-	/* Handle high and low extremes */
-	if (c == 0)
-		c = 1;
-	if (c > 255)
-		c = 0; /* 0 set division by 256 */
-	period_cycles = c;
-
-	/* The duty-cycle value is as follows:
-	 *
-	 *  DUTY-CYCLE     HIGH LEVEL
-	 *      1            99.9%
-	 *      25           90.0%
-	 *      128          50.0%
-	 *      220          10.0%
-	 *      255           0.1%
-	 *      0             0.0%
-	 *
-	 * In other words, the register value is duty-cycle % 256 with
-	 * duty-cycle in the range 1-256.
-	 */
-	c = 256 * duty_ns;
-	do_div(c, period_ns);
-	if (c > 255)
-		c = 255;
-	duty_cycles = 256 - c;
+	/* The highest acceptable divisor is 256, which is represented by 0 */
+	period_cycles = div64_u64(c * period_ns,
+			       (unsigned long long)NSEC_PER_SEC * 256);
+	if (!period_cycles)
+		period_cycles = 1;
+	if (period_cycles > 255)
+		period_cycles = 0;
+
+	/* Compute 256 x #duty/period value and care for corner cases */
+	duty_cycles = div64_u64((unsigned long long)(period_ns - duty_ns) * 256,
+				period_ns);
+	if (!duty_cycles)
+		duty_cycles = 1;
+	if (duty_cycles > 255)
+		duty_cycles = 255;
 
 	val = readl(lpc32xx->base + (pwm->hwpwm << 2));
 	val &= ~0xFFFF;
-	val |= PWM_RELOADV(period_cycles) | PWM_DUTY(duty_cycles);
+	val |= (period_cycles << 8) | duty_cycles;
 	writel(val, lpc32xx->base + (pwm->hwpwm << 2));
 
 	return 0;
@@ -124,9 +109,6 @@
 		return -ENOMEM;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res)
-		return -EINVAL;
-
 	lpc32xx->base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(lpc32xx->base))
 		return PTR_ERR(lpc32xx->base);
@@ -137,7 +119,7 @@
 
 	lpc32xx->chip.dev = &pdev->dev;
 	lpc32xx->chip.ops = &lpc32xx_pwm_ops;
-	lpc32xx->chip.npwm = 2;
+	lpc32xx->chip.npwm = 1;
 	lpc32xx->chip.base = -1;
 
 	ret = pwmchip_add(&lpc32xx->chip);
@@ -171,7 +153,7 @@
 static struct platform_driver lpc32xx_pwm_driver = {
 	.driver = {
 		.name = "lpc32xx-pwm",
-		.of_match_table = of_match_ptr(lpc32xx_pwm_dt_ids),
+		.of_match_table = lpc32xx_pwm_dt_ids,
 	},
 	.probe = lpc32xx_pwm_probe,
 	.remove = lpc32xx_pwm_remove,