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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-03-25 03:53:42 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-03-25 03:53:42 -0300
commit03dd4cb26d967f9588437b0fc9cc0e8353322bb7 (patch)
treefa581f6dc1c0596391690d1f67eceef3af8246dc /drivers/pwm/pwm-lpc32xx.c
parentd4e493caf788ef44982e131ff9c786546904d934 (diff)
Linux-libre 4.5-gnu
Diffstat (limited to 'drivers/pwm/pwm-lpc32xx.c')
-rw-r--r--drivers/pwm/pwm-lpc32xx.c59
1 files changed, 22 insertions, 37 deletions
diff --git a/drivers/pwm/pwm-lpc32xx.c b/drivers/pwm/pwm-lpc32xx.c
index 9fde60ce8..4d470c1a4 100644
--- a/drivers/pwm/pwm-lpc32xx.c
+++ b/drivers/pwm/pwm-lpc32xx.c
@@ -24,9 +24,7 @@ struct lpc32xx_pwm_chip {
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 @@ static int lpc32xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
unsigned long long c;
int period_cycles, duty_cycles;
u32 val;
-
- 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;
+ c = clk_get_rate(lpc32xx->clk);
+
+ /* 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 > 256)
+ return -ERANGE;
+ if (period_cycles == 256)
+ 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;
@@ -83,7 +68,7 @@ static int lpc32xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
u32 val;
int ret;
- ret = clk_enable(lpc32xx->clk);
+ ret = clk_prepare_enable(lpc32xx->clk);
if (ret)
return ret;
@@ -103,7 +88,7 @@ static void lpc32xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
val &= ~PWM_ENABLE;
writel(val, lpc32xx->base + (pwm->hwpwm << 2));
- clk_disable(lpc32xx->clk);
+ clk_disable_unprepare(lpc32xx->clk);
}
static const struct pwm_ops lpc32xx_pwm_ops = {
@@ -134,7 +119,7 @@ static int lpc32xx_pwm_probe(struct platform_device *pdev)
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);