On Tue, Jul 12, 2022 at 11:01:11AM +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@xxxxxxxxxx>
> ---
> drivers/pwm/pwm-dwc.c | 17 +++++++++++++++++
> 1 file changed, 17 insertions(+)
>
> diff --git a/drivers/pwm/pwm-dwc.c b/drivers/pwm/pwm-dwc.c
> index 235cb730c888..aa0486b89bdd 100644
> --- a/drivers/pwm/pwm-dwc.c
> +++ b/drivers/pwm/pwm-dwc.c
> @@ -18,6 +18,7 @@
> #include <linux/kernel.h>
> #include <linux/module.h>
> #include <linux/pci.h>
> +#include <linux/clk.h>
> #include <linux/platform_device.h>
> #include <linux/pm_runtime.h>
> #include <linux/pwm.h>
> @@ -35,7 +36,12 @@
> #define DWC_TIMERS_COMP_VERSION 0xac
>
> #define DWC_TIMERS_TOTAL 8
> +
> +#ifndef CONFIG_OF
> #define DWC_CLK_PERIOD_NS 10
> +#else
> +#define DWC_CLK_PERIOD_NS dwc->clk_ns
> +#endif
Hmm, that looks wrong. If you have CONFIG_OF but use the pci device ...
IMHO it would help readability if you used ifdef. When there is an #else
branch anyhow, there is no reason to use the negative variant.
> /* Timer Control Register */
> #define DWC_TIM_CTRL_EN BIT(0)
> @@ -54,6 +60,8 @@ 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))
> @@ -336,6 +344,14 @@ static int dwc_pwm_plat_probe(struct platform_device *pdev)
> return dev_err_probe(dev, PTR_ERR(dwc->base),
> "failed to map IO\n");
>
> + dwc->clk = devm_clk_get(dev, "timer");
> + if (IS_ERR(dwc->clk))
> + return dev_err_probe(dev, PTR_ERR(dwc->clk),
> + "failed to get timer clock\n");
> +
> + clk_prepare_enable(dwc->clk);
> + dwc->clk_ns = 1000000000 /clk_get_rate(dwc->clk);
> +
> ret = pwmchip_add(&dwc->chip);
> if (ret)
> return ret;
Here you're missing clk_disable_unprepare(). (Alternatively use
devm_clk_get_enabled().)
> @@ -347,6 +363,7 @@ static int dwc_pwm_plat_remove(struct platform_device *pdev)
> {
> struct dwc_pwm *dwc = platform_get_drvdata(pdev);
>
> + clk_disable_unprepare(dwc->clk);
> pwmchip_remove(&dwc->chip);
The order is wrong here. You must only stop the clk when the pwmchip is
removed. Until that the PWM is supposed to stay functional.
> return 0;
> }
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
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