[PATCH 3/7] pwm: dwc: add of/platform support

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

The dwc pwm controller can be used in non-PCI systems, so allow
either platform or OF based probing.

Signed-off-by: Ben Dooks <ben.dooks@sifive.com>
---
 .../devicetree/bindings/pwm/pwm-synposys.yaml | 40 ++++++++++++++
 drivers/pwm/Kconfig                           |  5 +-
 drivers/pwm/pwm-dwc.c                         | 53 +++++++++++++++++++
 3 files changed, 96 insertions(+), 2 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/pwm/pwm-synposys.yaml

diff --git a/Documentation/devicetree/bindings/pwm/pwm-synposys.yaml b/Documentation/devicetree/bindings/pwm/pwm-synposys.yaml
new file mode 100644
index 000000000000..38ac0da75272
--- /dev/null
+++ b/Documentation/devicetree/bindings/pwm/pwm-synposys.yaml
@@ -0,0 +1,40 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright (C) 2022 SiFive, Inc.
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/pwm-synposys.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Synopsys PWM controller
+
+maintainers:
+   - Ben Dooks <ben.dooks@sifive.com>
+
+properties:
+  "#pwm-cells":
+    description: |
+      See pwm.yaml in this directory for a description of the cells format.
+
+  clocks:
+    items:
+      - description: Interface bus clock
+      - description: PWM reference clock
+
+  clock-names:
+    items:
+      - const: bus
+      - const: timer
+
+  compatible:
+    oneOf:
+      - items:
+        - const: snps,pwm
+
+required:
+  - "#pwm-cells"
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+
+additionalProperties: false
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 904de8d61828..e1aa645c1084 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -166,9 +166,10 @@ config PWM_CROS_EC
 
 config PWM_DWC
 	tristate "DesignWare PWM Controller"
-	depends on PCI
+	depends on PCI || OF
 	help
-	  PWM driver for Synopsys DWC PWM Controller attached to a PCI bus.
+	  PWM driver for Synopsys DWC PWM Controller attached to either a
+	  PCI or platform bus.
 
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-dwc.
diff --git a/drivers/pwm/pwm-dwc.c b/drivers/pwm/pwm-dwc.c
index 61f11e0a9319..235cb730c888 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/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/pwm.h>
 
@@ -319,6 +320,58 @@ static struct pci_driver dwc_pwm_driver = {
 
 module_pci_driver(dwc_pwm_driver);
 
+#ifdef CONFIG_OF
+static int dwc_pwm_plat_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct dwc_pwm *dwc;
+	int ret;
+
+	dwc = dwc_pwm_alloc(dev);
+	if (!dwc)
+		return -ENOMEM;
+
+	dwc->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(dwc->base))
+		return dev_err_probe(dev, PTR_ERR(dwc->base),
+				     "failed to map IO\n");
+
+	ret = pwmchip_add(&dwc->chip);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int dwc_pwm_plat_remove(struct platform_device *pdev)
+{
+	struct dwc_pwm *dwc = platform_get_drvdata(pdev);
+
+	pwmchip_remove(&dwc->chip);
+	return 0;
+}
+
+static const struct of_device_id dwc_pwm_dt_ids[] = {
+	{ .compatible = "snps,pwm" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, dwc_pwm_dt_ids);
+
+static struct platform_driver dwc_pwm_plat_driver = {
+	.driver = {
+		.name		= "dwc-pwm",
+		.of_match_table  = dwc_pwm_dt_ids,
+	},
+	.probe	= dwc_pwm_plat_probe,
+	.remove	= dwc_pwm_plat_remove,
+};
+
+module_platform_driver(dwc_pwm_plat_driver);
+
+MODULE_ALIAS("platform:dwc-pwm");
+#endif /* CONFIG_OF */
+
+
 MODULE_AUTHOR("Felipe Balbi (Intel)");
 MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@linux.intel.com>");
 MODULE_AUTHOR("Raymond Tan <raymond.tan@intel.com>");
-- 
2.35.1