Merge tag 'pwm/for-6.16-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux

8a2ba6f8 · Linus Torvalds <[email protected]> · 2025-06-06 13:16:50 -07:00

Pull pwm fixes from Uwe Kleine-König:
 "axi-pwmgen: Fix handling of external clock

  The pwm-axi-pwmgen device is backed by an FPGA and can be synthesized
  in different ways. Relevant here is that it can use one or two
  external clock signals. These fix clock handling for the two clocks
  case"

* tag 'pwm/for-6.16-rc1-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux:
  pwm: axi-pwmgen: fix missing separate external clock
  dt-bindings: pwm: adi,axi-pwmgen: Fix clocks

Commit: 8a2ba6f8ee7dd764ffec4484e4f4d5ad377f9a69
Parents: 6d885421 · a8841dc3

Merge commit. Changes below are compared with the first parent: 6d885421.

Changes

2 files changed · +31 −5

File	Status	Add	Del	Content
Documentation/devicetree/bindings/pwm/adi,axi-pwmgen.yaml	modified	+11	−2	View file
drivers/pwm/pwm-axi-pwmgen.c	modified	+20	−3	View file

Documentation/devicetree/bindings/pwm/adi,axi-pwmgen.yaml

View file

diff --git a/Documentation/devicetree/bindings/pwm/adi,axi-pwmgen.yaml b/Documentation/devicetree/bindings/pwm/adi,axi-pwmgen.yaml
index 45e112d..5575c58 100644
--- a/Documentation/devicetree/bindings/pwm/adi,axi-pwmgen.yaml
+++ b/Documentation/devicetree/bindings/pwm/adi,axi-pwmgen.yaml
@@ -30,11 +30,19 @@ properties:
     const: 3
 
   clocks:
-    maxItems: 1
+    minItems: 1
+    maxItems: 2
+
+  clock-names:
+    minItems: 1
+    items:
+      - const: axi
+      - const: ext
 
 required:
   - reg
   - clocks
+  - clock-names
 
 unevaluatedProperties: false
 
@@ -43,6 +51,7 @@ examples:
     pwm@44b00000 {
         compatible = "adi,axi-pwmgen-2.00.a";
         reg = <0x44b00000 0x1000>;
-        clocks = <&spi_clk>;
+        clocks = <&fpga_clk>, <&spi_clk>;
+        clock-names = "axi", "ext";
         #pwm-cells = <3>;
     };

drivers/pwm/pwm-axi-pwmgen.c

View file

diff --git a/drivers/pwm/pwm-axi-pwmgen.c b/drivers/pwm/pwm-axi-pwmgen.c
index 4337c8f..60dcd35 100644
--- a/drivers/pwm/pwm-axi-pwmgen.c
+++ b/drivers/pwm/pwm-axi-pwmgen.c
@@ -257,7 +257,7 @@ static int axi_pwmgen_probe(struct platform_device *pdev)
 	struct regmap *regmap;
 	struct pwm_chip *chip;
 	struct axi_pwmgen_ddata *ddata;
-	struct clk *clk;
+	struct clk *axi_clk, *clk;
 	void __iomem *io_base;
 	int ret;
 
@@ -280,9 +280,26 @@ static int axi_pwmgen_probe(struct platform_device *pdev)
 	ddata = pwmchip_get_drvdata(chip);
 	ddata->regmap = regmap;
 
-	clk = devm_clk_get_enabled(dev, NULL);
+	/*
+	 * Using NULL here instead of "axi" for backwards compatibility. There
+	 * are some dtbs that don't give clock-names and have the "ext" clock
+	 * as the one and only clock (due to mistake in the original bindings).
+	 */
+	axi_clk = devm_clk_get_enabled(dev, NULL);
+	if (IS_ERR(axi_clk))
+		return dev_err_probe(dev, PTR_ERR(axi_clk), "failed to get axi clock\n");
+
+	clk = devm_clk_get_optional_enabled(dev, "ext");
 	if (IS_ERR(clk))
-		return dev_err_probe(dev, PTR_ERR(clk), "failed to get clock\n");
+		return dev_err_probe(dev, PTR_ERR(clk), "failed to get ext clock\n");
+
+	/*
+	 * If there is no "ext" clock, it means the HDL was compiled with
+	 * ASYNC_CLK_EN=0. In this case, the AXI clock is also used for the
+	 * PWM output clock.
+	 */
+	if (!clk)
+		clk = axi_clk;
 
 	ret = devm_clk_rate_exclusive_get(dev, clk);
 	if (ret)