[v6,07/10] pwm: dwc: make timer clock configurable

Message ID 20221020151610.59443-8-ben.dooks@sifive.com
State New
Headers
Series Designware PWM driver updates for OF |

Commit Message

Ben Dooks Oct. 20, 2022, 3:16 p.m. UTC
  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@sifive.com>
---
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-pci.c |  1 +
 drivers/pwm/pwm-dwc.c     | 10 ++++++----
 drivers/pwm/pwm-dwc.h     |  3 ++-
 3 files changed, 9 insertions(+), 5 deletions(-)
  

Comments

Uwe Kleine-König Nov. 10, 2022, 3:39 p.m. UTC | #1
Hello,

On Thu, Oct 20, 2022 at 04:16:07PM +0100, Ben Dooks wrote:
> 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@sifive.com>
> ---
> 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-pci.c |  1 +
>  drivers/pwm/pwm-dwc.c     | 10 ++++++----
>  drivers/pwm/pwm-dwc.h     |  3 ++-
>  3 files changed, 9 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/pwm/pwm-dwc-pci.c b/drivers/pwm/pwm-dwc-pci.c
> index 2213d0e7f3c8..949423e368f9 100644
> --- a/drivers/pwm/pwm-dwc-pci.c
> +++ b/drivers/pwm/pwm-dwc-pci.c
> @@ -20,6 +20,7 @@
>  #include <linux/pci.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/pwm.h>
> +#include <linux/clk.h>
>  
>  #include "pwm-dwc.h"
>  

I assume this is only needed because pwm-dwc.h now uses struct clk.
Maybe just add

	struct clk;

to the pwm-dwc.h instead of this hunk?

> [...]
> diff --git a/drivers/pwm/pwm-dwc.h b/drivers/pwm/pwm-dwc.h
> index 68f98eb76152..dc451cb2eff5 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 +40,8 @@ struct dwc_pwm_ctx {
>  struct dwc_pwm {
>  	struct pwm_chip chip;
>  	void __iomem *base;
> +	struct clk *clk;

This is unsed, please add it in the patch that makes use of it.

> +	unsigned int clk_ns;
>  	struct dwc_pwm_ctx ctx[DWC_TIMERS_TOTAL];
>  };
>  #define to_dwc_pwm(p)	(container_of((p), struct dwc_pwm, chip))

Best regards
Uwe
  

Patch

diff --git a/drivers/pwm/pwm-dwc-pci.c b/drivers/pwm/pwm-dwc-pci.c
index 2213d0e7f3c8..949423e368f9 100644
--- a/drivers/pwm/pwm-dwc-pci.c
+++ b/drivers/pwm/pwm-dwc-pci.c
@@ -20,6 +20,7 @@ 
 #include <linux/pci.h>
 #include <linux/pm_runtime.h>
 #include <linux/pwm.h>
+#include <linux/clk.h>
 
 #include "pwm-dwc.h"
 
diff --git a/drivers/pwm/pwm-dwc.c b/drivers/pwm/pwm-dwc.c
index 90a8ae1252a1..1251620ab771 100644
--- a/drivers/pwm/pwm-dwc.c
+++ b/drivers/pwm/pwm-dwc.c
@@ -14,6 +14,7 @@ 
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/clk.h>
 #include <linux/pm_runtime.h>
 #include <linux/pwm.h>
 
@@ -47,13 +48,13 @@  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 +129,12 @@  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 +157,7 @@  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..dc451cb2eff5 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 +40,8 @@  struct dwc_pwm_ctx {
 struct dwc_pwm {
 	struct pwm_chip chip;
 	void __iomem *base;
+	struct clk *clk;
+	unsigned int clk_ns;
 	struct dwc_pwm_ctx ctx[DWC_TIMERS_TOTAL];
 };
 #define to_dwc_pwm(p)	(container_of((p), struct dwc_pwm, chip))