[PATCH v7 07/10] pwm: dwc: make timer clock configurable

From: Ben Dooks
Date: Fri Dec 23 2022 - 10:38:59 EST


Add a configurable clock base rate for the pwm as when being built
for non-PCI the block may be sourced from an internal clock.

Signed-off-by: Ben Dooks <ben.dooks@xxxxxxxxxx>
---
v7:
- remove the "struct clk *" clk field from dwc_pwm_ctx, not used here,
v6:
- removed DWC_CLK_PERIOD_NS as it is now not needed
v4:
- moved earlier before the of changes to make the of changes one patch
v2:
- removed the ifdef and merged the other clock patch in here
---
drivers/pwm/pwm-dwc.c | 9 +++++----
drivers/pwm/pwm-dwc.h | 2 +-
2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/pwm/pwm-dwc.c b/drivers/pwm/pwm-dwc.c
index 90a8ae1252a1..0c6beafa8c41 100644
--- a/drivers/pwm/pwm-dwc.c
+++ b/drivers/pwm/pwm-dwc.c
@@ -47,13 +47,13 @@ static int __dwc_pwm_configure_timer(struct dwc_pwm *dwc,
* periods and check are the result within HW limits between 1 and
* 2^32 periods.
*/
- tmp = DIV_ROUND_CLOSEST_ULL(state->duty_cycle, DWC_CLK_PERIOD_NS);
+ tmp = DIV_ROUND_CLOSEST_ULL(state->duty_cycle, dwc->clk_ns);
if (tmp < 1 || tmp > (1ULL << 32))
return -ERANGE;
low = tmp - 1;

tmp = DIV_ROUND_CLOSEST_ULL(state->period - state->duty_cycle,
- DWC_CLK_PERIOD_NS);
+ dwc->clk_ns);
if (tmp < 1 || tmp > (1ULL << 32))
return -ERANGE;
high = tmp - 1;
@@ -128,12 +128,12 @@ static void dwc_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,

duty = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT(pwm->hwpwm));
duty += 1;
- duty *= DWC_CLK_PERIOD_NS;
+ duty *= dwc->clk_ns;
state->duty_cycle = duty;

period = dwc_pwm_readl(dwc, DWC_TIM_LD_CNT2(pwm->hwpwm));
period += 1;
- period *= DWC_CLK_PERIOD_NS;
+ period *= dwc->clk_ns;
period += duty;
state->period = period;

@@ -156,6 +156,7 @@ struct dwc_pwm *dwc_pwm_alloc(struct device *dev)
if (!dwc)
return NULL;

+ dwc->clk_ns = 10;
dwc->chip.dev = dev;
dwc->chip.ops = &dwc_pwm_ops;
dwc->chip.npwm = DWC_TIMERS_TOTAL;
diff --git a/drivers/pwm/pwm-dwc.h b/drivers/pwm/pwm-dwc.h
index 68f98eb76152..b29d8cd21208 100644
--- a/drivers/pwm/pwm-dwc.h
+++ b/drivers/pwm/pwm-dwc.h
@@ -22,7 +22,6 @@
#define DWC_TIMERS_COMP_VERSION 0xac

#define DWC_TIMERS_TOTAL 8
-#define DWC_CLK_PERIOD_NS 10

/* Timer Control Register */
#define DWC_TIM_CTRL_EN BIT(0)
@@ -41,6 +40,7 @@ struct dwc_pwm_ctx {
struct dwc_pwm {
struct pwm_chip chip;
void __iomem *base;
+ unsigned int clk_ns;
struct dwc_pwm_ctx ctx[DWC_TIMERS_TOTAL];
};
#define to_dwc_pwm(p) (container_of((p), struct dwc_pwm, chip))
--
2.35.1