[PATCH 5/7] pwm: dwc: add timer clock

[Ben Dooks <ben.dooks@sifive.com>]

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>
---
 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
 
 /* 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;
@@ -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);
 	return 0;
 }
-- 
2.35.1