Merge tag 'pwm/for-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux

Pull pwm updates from Uwe Kleine-König: "Here comes the usual mix of cleanups, new dt-bindings for existing drivers and nexus nodes; and a new driver for the pwm subsystem. Patches were contributed by Andy Shevchenko, Chen Wang, Chukun Pan, Frank Li, Herve Codina, Kever Yang, and Nam Cao. Patch feedback was provided by Andy Shevchenko, Conor Dooley, Daniel Mack, Duje Mihanović, Heiko Stuebner, Herve Codina, Krzysztof Kozlowski, Neil Armstrong, Rob Herring, and Zack Rusin. Thanks to all of them" * tag 'pwm/for-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/linux: dt-bindings: pwm: imx: Add i.MX93, i.MX94 and i.MX95 support dt-bindings: pwm: rockchip: Add rockchip,rk3528-pwm pwm: stmpe: Allow to compile as a module pwm: Check for CONFIG_PWM using IS_REACHABLE() in main header dt-bindings: pwm: rockchip: Add rockchip,rk3562-pwm pwm: Strengthen dependency for PWM_SIFIVE pwm: clps711x: Drop of_match_ptr() usage for .of_match_table pwm: pca9685: Drop ACPI_PTR() and of_match_ptr() pwm: Add support for pwm nexus dt bindings dt-bindings: pwm: Add support for PWM nexus node pwm: Add upgrade path to #pwm-cells = <3> for users of of_pwm_single_xlate() pwm: gpio: Switch to use hrtimer_setup() pwm: sophgo: add driver for Sophgo SG2042 PWM dt-bindings: pwm: sophgo: add PWM controller for SG2042 pwm: lpss: Only include <linux/pwm.h> where needed
2026-05-10 21:14:56 -04:00 · 2025-03-25 19:46:19 -07:00
parent 47618bc875 6df320abbb
commit 5e0c2cc4c3
15 changed files with 390 additions and 23 deletions
--- a/Documentation/devicetree/bindings/pwm/imx-tpm-pwm.yaml
+++ b/Documentation/devicetree/bindings/pwm/imx-tpm-pwm.yaml
@@ -23,8 +23,15 @@ properties:
    const: 3

  compatible:
-    enum:
-      - fsl,imx7ulp-pwm
+    oneOf:
+      - enum:
+          - fsl,imx7ulp-pwm
+      - items:
+          - enum:
+              - fsl,imx93-pwm
+              - fsl,imx94-pwm
+              - fsl,imx95-pwm
+          - const: fsl,imx7ulp-pwm

  reg:
    maxItems: 1
--- a/Documentation/devicetree/bindings/pwm/pwm-nexus-node.yaml
+++ b/Documentation/devicetree/bindings/pwm/pwm-nexus-node.yaml
@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/pwm-nexus-node.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: PWM Nexus node properties
+
+description: >
+  Platforms can have a standardized connector/expansion slot that exposes PWMs
+  signals to expansion boards.
+
+  A nexus node allows to remap a phandle list in a consumer node through a
+  connector node in a generic way. With this remapping, the consumer node needs
+  to know only about the nexus node. Resources behind the nexus node are
+  decoupled by the nexus node itself.
+
+maintainers:
+  - Herve Codina <herve.codina@bootlin.com>
+
+select: true
+
+properties:
+  '#pwm-cells': true
+
+  pwm-map:
+    $ref: /schemas/types.yaml#/definitions/uint32-matrix
+
+  pwm-map-mask:
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+
+  pwm-map-pass-thru:
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+
+dependentRequired:
+  pwm-map: ['#pwm-cells']
+  pwm-map-mask: [ pwm-map ]
+  pwm-map-pass-thru: [ pwm-map ]
+
+additionalProperties: true
+
+examples:
+  - |
+        pwm1: pwm@100 {
+            reg = <0x100 0x10>;
+            #pwm-cells = <3>;
+        };
+
+        pwm2: pwm@200 {
+            reg = <0x200 0x10>;
+            #pwm-cells = <3>;
+        };
+
+        connector: connector {
+            #pwm-cells = <3>;
+            pwm-map = <0 0 0 &pwm1 1 0 0>,
+                      <1 0 0 &pwm2 4 0 0>,
+                      <2 0 0 &pwm1 3 0 0>;
+            pwm-map-mask = <0xffffffff 0x0 0x0>;
+            pwm-map-pass-thru = <0x0 0xffffffff 0xffffffff>;
+        };
+
+        device {
+            pwms = <&connector 1 57000 0>;
+        };
--- a/Documentation/devicetree/bindings/pwm/pwm-rockchip.yaml
+++ b/Documentation/devicetree/bindings/pwm/pwm-rockchip.yaml
@@ -30,6 +30,8 @@ properties:
          - enum:
              - rockchip,px30-pwm
              - rockchip,rk3308-pwm
+              - rockchip,rk3528-pwm
+              - rockchip,rk3562-pwm
              - rockchip,rk3568-pwm
              - rockchip,rk3588-pwm
              - rockchip,rv1126-pwm
--- a/Documentation/devicetree/bindings/pwm/sophgo,sg2042-pwm.yaml
+++ b/Documentation/devicetree/bindings/pwm/sophgo,sg2042-pwm.yaml
@@ -0,0 +1,58 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pwm/sophgo,sg2042-pwm.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Sophgo SG2042 PWM controller
+
+maintainers:
+  - Chen Wang <unicorn_wang@outlook.com>
+
+description:
+  This controller contains 4 channels which can generate PWM waveforms.
+
+allOf:
+  - $ref: pwm.yaml#
+
+properties:
+  compatible:
+    const: sophgo,sg2042-pwm
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    items:
+      - const: apb
+
+  resets:
+    maxItems: 1
+
+  "#pwm-cells":
+    const: 3
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - resets
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/reset/sophgo,sg2042-reset.h>
+
+    pwm@7f006000 {
+        compatible = "sophgo,sg2042-pwm";
+        reg = <0x7f006000 0x1000>;
+        #pwm-cells = <3>;
+        clocks = <&clock 67>;
+        clock-names = "apb";
+        resets = <&rstgen RST_PWM>;
+    };
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -567,7 +567,7 @@ config PWM_SIFIVE
 	tristate "SiFive PWM support"
 	depends on OF
 	depends on COMMON_CLK && HAS_IOMEM
-	depends on RISCV || COMPILE_TEST
+	depends on ARCH_SIFIVE || COMPILE_TEST
 	help
 	  Generic PWM framework driver for SiFive SoCs.

@@ -584,6 +584,16 @@ config PWM_SL28CPLD
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-sl28cpld.

+config PWM_SOPHGO_SG2042
+	tristate "Sophgo SG2042 PWM support"
+	depends on ARCH_SOPHGO || COMPILE_TEST
+	help
+	  PWM driver for the PWM controller on Sophgo SG2042 SoC. The PWM
+	  controller supports outputing 4 channels of PWM waveforms.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called pwm_sophgo_sg2042.
+
 config PWM_SPEAR
 	tristate "STMicroelectronics SPEAr PWM support"
 	depends on PLAT_SPEAR || COMPILE_TEST
@@ -636,7 +646,7 @@ config PWM_STM32_LP
 	  will be called pwm-stm32-lp.

 config PWM_STMPE
-	bool "STMPE expander PWM export"
+	tristate "STMPE expander PWM export"
 	depends on MFD_STMPE
 	help
 	  This enables support for the PWMs found in the STMPE I/O
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@@ -53,6 +53,7 @@ obj-$(CONFIG_PWM_RZ_MTU3)	+= pwm-rz-mtu3.o
 obj-$(CONFIG_PWM_SAMSUNG)	+= pwm-samsung.o
 obj-$(CONFIG_PWM_SIFIVE)	+= pwm-sifive.o
 obj-$(CONFIG_PWM_SL28CPLD)	+= pwm-sl28cpld.o
+obj-$(CONFIG_PWM_SOPHGO_SG2042)	+= pwm-sophgo-sg2042.o
 obj-$(CONFIG_PWM_SPEAR)		+= pwm-spear.o
 obj-$(CONFIG_PWM_SPRD)		+= pwm-sprd.o
 obj-$(CONFIG_PWM_STI)		+= pwm-sti.o
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -1000,11 +1000,27 @@ of_pwm_xlate_with_flags(struct pwm_chip *chip, const struct of_phandle_args *arg
 }
 EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags);

+/*
+ * This callback is used for PXA PWM chips that only have a single PWM line.
+ * For such chips you could argue that passing the line number (i.e. the first
+ * parameter in the common case) is useless as it's always zero. So compared to
+ * the default xlate function of_pwm_xlate_with_flags() the first parameter is
+ * the default period and the second are flags.
+ *
+ * Note that if #pwm-cells = <3>, the semantic is the same as for
+ * of_pwm_xlate_with_flags() to allow converting the affected driver to
+ * #pwm-cells = <3> without breaking the legacy binding.
+ *
+ * Don't use for new drivers.
+ */
 struct pwm_device *
 of_pwm_single_xlate(struct pwm_chip *chip, const struct of_phandle_args *args)
 {
 	struct pwm_device *pwm;

+	if (args->args_count >= 3)
+		return of_pwm_xlate_with_flags(chip, args);
+
 	pwm = pwm_request_from_chip(chip, 0, NULL);
 	if (IS_ERR(pwm))
 		return pwm;
@@ -1716,8 +1732,7 @@ static struct pwm_device *of_pwm_get(struct device *dev, struct device_node *np,
 			return ERR_PTR(index);
 	}

-	err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index,
-					 &args);
+	err = of_parse_phandle_with_args_map(np, "pwms", "pwm", index, &args);
 	if (err) {
 		pr_err("%s(): can't parse \"pwms\" property\n", __func__);
 		return ERR_PTR(err);
--- a/drivers/pwm/pwm-clps711x.c
+++ b/drivers/pwm/pwm-clps711x.c
@@ -98,7 +98,7 @@ static int clps711x_pwm_probe(struct platform_device *pdev)
 	return devm_pwmchip_add(&pdev->dev, chip);
 }

-static const struct of_device_id __maybe_unused clps711x_pwm_dt_ids[] = {
+static const struct of_device_id clps711x_pwm_dt_ids[] = {
 	{ .compatible = "cirrus,ep7209-pwm", },
 	{ }
 };
@@ -107,7 +107,7 @@ MODULE_DEVICE_TABLE(of, clps711x_pwm_dt_ids);
 static struct platform_driver clps711x_pwm_driver = {
 	.driver = {
 		.name = "clps711x-pwm",
-		.of_match_table = of_match_ptr(clps711x_pwm_dt_ids),
+		.of_match_table = clps711x_pwm_dt_ids,
 	},
 	.probe = clps711x_pwm_probe,
 };
--- a/drivers/pwm/pwm-gpio.c
+++ b/drivers/pwm/pwm-gpio.c
@@ -207,13 +207,12 @@ static int pwm_gpio_probe(struct platform_device *pdev)
 	chip->ops = &pwm_gpio_ops;
 	chip->atomic = true;

-	hrtimer_init(&gpwm->gpio_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	hrtimer_setup(&gpwm->gpio_timer, pwm_gpio_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+
 	ret = devm_add_action_or_reset(dev, pwm_gpio_disable_hrtimer, gpwm);
 	if (ret)
 		return ret;

-	gpwm->gpio_timer.function = pwm_gpio_timer;
-
 	ret = pwmchip_add(chip);
 	if (ret < 0)
 		return dev_err_probe(dev, ret, "could not add pwmchip\n");
--- a/drivers/pwm/pwm-lpss.c
+++ b/drivers/pwm/pwm-lpss.c
@@ -17,6 +17,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
+#include <linux/pwm.h>
 #include <linux/time.h>

 #define DEFAULT_SYMBOL_NAMESPACE "PWM_LPSS"
--- a/drivers/pwm/pwm-lpss.h
+++ b/drivers/pwm/pwm-lpss.h
@@ -10,7 +10,6 @@
 #ifndef __PWM_LPSS_H
 #define __PWM_LPSS_H

-#include <linux/pwm.h>
 #include <linux/types.h>

 #include <linux/platform_data/x86/pwm-lpss.h>
--- a/drivers/pwm/pwm-pca9685.c
+++ b/drivers/pwm/pwm-pca9685.c
@@ -8,7 +8,6 @@
 * based on the pwm-twl-led.c driver
 */

-#include <linux/acpi.h>
 #include <linux/gpio/driver.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
@@ -639,21 +638,17 @@ static const struct i2c_device_id pca9685_id[] = {
 };
 MODULE_DEVICE_TABLE(i2c, pca9685_id);

-#ifdef CONFIG_ACPI
 static const struct acpi_device_id pca9685_acpi_ids[] = {
 	{ "INT3492", 0 },
 	{ /* sentinel */ },
 };
 MODULE_DEVICE_TABLE(acpi, pca9685_acpi_ids);
-#endif

-#ifdef CONFIG_OF
 static const struct of_device_id pca9685_dt_ids[] = {
 	{ .compatible = "nxp,pca9685-pwm", },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, pca9685_dt_ids);
-#endif

 static const struct dev_pm_ops pca9685_pwm_pm = {
 	SET_RUNTIME_PM_OPS(pca9685_pwm_runtime_suspend,
@@ -663,8 +658,8 @@ static const struct dev_pm_ops pca9685_pwm_pm = {
 static struct i2c_driver pca9685_i2c_driver = {
 	.driver = {
 		.name = "pca9685-pwm",
-		.acpi_match_table = ACPI_PTR(pca9685_acpi_ids),
-		.of_match_table = of_match_ptr(pca9685_dt_ids),
+		.acpi_match_table = pca9685_acpi_ids,
+		.of_match_table = pca9685_dt_ids,
 		.pm = &pca9685_pwm_pm,
 	},
 	.probe = pca9685_pwm_probe,
--- a/drivers/pwm/pwm-sophgo-sg2042.c
+++ b/drivers/pwm/pwm-sophgo-sg2042.c
@@ -0,0 +1,194 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Sophgo SG2042 PWM Controller Driver
+ *
+ * Copyright (C) 2024 Sophgo Technology Inc.
+ * Copyright (C) 2024 Chen Wang <unicorn_wang@outlook.com>
+ *
+ * Limitations:
+ * - After reset, the output of the PWM channel is always high.
+ *   The value of HLPERIOD/PERIOD is 0.
+ * - When HLPERIOD or PERIOD is reconfigured, PWM will start to
+ *   output waveforms with the new configuration after completing
+ *   the running period.
+ * - When PERIOD and HLPERIOD is set to 0, the PWM wave output will
+ *   be stopped and the output is pulled to high.
+ * See the datasheet [1] for more details.
+ * [1]:https://github.com/sophgo/sophgo-doc/tree/main/SG2042/TRM
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/math64.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/reset.h>
+
+/*
+ * Offset RegisterName
+ * 0x0000 HLPERIOD0
+ * 0x0004 PERIOD0
+ * 0x0008 HLPERIOD1
+ * 0x000C PERIOD1
+ * 0x0010 HLPERIOD2
+ * 0x0014 PERIOD2
+ * 0x0018 HLPERIOD3
+ * 0x001C PERIOD3
+ * Four groups and every group is composed of HLPERIOD & PERIOD
+ */
+#define SG2042_PWM_HLPERIOD(chan) ((chan) * 8 + 0)
+#define SG2042_PWM_PERIOD(chan) ((chan) * 8 + 4)
+
+#define SG2042_PWM_CHANNELNUM	4
+
+/**
+ * struct sg2042_pwm_ddata - private driver data
+ * @base:		base address of mapped PWM registers
+ * @clk_rate_hz:	rate of base clock in HZ
+ */
+struct sg2042_pwm_ddata {
+	void __iomem *base;
+	unsigned long clk_rate_hz;
+};
+
+/*
+ * period_ticks: PERIOD
+ * hlperiod_ticks: HLPERIOD
+ */
+static void pwm_sg2042_config(struct sg2042_pwm_ddata *ddata, unsigned int chan,
+			      u32 period_ticks, u32 hlperiod_ticks)
+{
+	void __iomem *base = ddata->base;
+
+	writel(period_ticks, base + SG2042_PWM_PERIOD(chan));
+	writel(hlperiod_ticks, base + SG2042_PWM_HLPERIOD(chan));
+}
+
+static int pwm_sg2042_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			    const struct pwm_state *state)
+{
+	struct sg2042_pwm_ddata *ddata = pwmchip_get_drvdata(chip);
+	u32 hlperiod_ticks;
+	u32 period_ticks;
+
+	if (state->polarity == PWM_POLARITY_INVERSED)
+		return -EINVAL;
+
+	if (!state->enabled) {
+		pwm_sg2042_config(ddata, pwm->hwpwm, 0, 0);
+		return 0;
+	}
+
+	/*
+	 * Duration of High level (duty_cycle) = HLPERIOD x Period_of_input_clk
+	 * Duration of One Cycle (period) = PERIOD x Period_of_input_clk
+	 */
+	period_ticks = min(mul_u64_u64_div_u64(ddata->clk_rate_hz, state->period, NSEC_PER_SEC), U32_MAX);
+	hlperiod_ticks = min(mul_u64_u64_div_u64(ddata->clk_rate_hz, state->duty_cycle, NSEC_PER_SEC), U32_MAX);
+
+	dev_dbg(pwmchip_parent(chip), "chan[%u]: PERIOD=%u, HLPERIOD=%u\n",
+		pwm->hwpwm, period_ticks, hlperiod_ticks);
+
+	pwm_sg2042_config(ddata, pwm->hwpwm, period_ticks, hlperiod_ticks);
+
+	return 0;
+}
+
+static int pwm_sg2042_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+				struct pwm_state *state)
+{
+	struct sg2042_pwm_ddata *ddata = pwmchip_get_drvdata(chip);
+	unsigned int chan = pwm->hwpwm;
+	u32 hlperiod_ticks;
+	u32 period_ticks;
+
+	period_ticks = readl(ddata->base + SG2042_PWM_PERIOD(chan));
+	hlperiod_ticks = readl(ddata->base + SG2042_PWM_HLPERIOD(chan));
+
+	if (!period_ticks) {
+		state->enabled = false;
+		return 0;
+	}
+
+	if (hlperiod_ticks > period_ticks)
+		hlperiod_ticks = period_ticks;
+
+	state->enabled = true;
+	state->period = DIV_ROUND_UP_ULL((u64)period_ticks * NSEC_PER_SEC, ddata->clk_rate_hz);
+	state->duty_cycle = DIV_ROUND_UP_ULL((u64)hlperiod_ticks * NSEC_PER_SEC, ddata->clk_rate_hz);
+	state->polarity = PWM_POLARITY_NORMAL;
+
+	return 0;
+}
+
+static const struct pwm_ops pwm_sg2042_ops = {
+	.apply = pwm_sg2042_apply,
+	.get_state = pwm_sg2042_get_state,
+};
+
+static const struct of_device_id sg2042_pwm_ids[] = {
+	{ .compatible = "sophgo,sg2042-pwm" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, sg2042_pwm_ids);
+
+static int pwm_sg2042_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct sg2042_pwm_ddata *ddata;
+	struct reset_control *rst;
+	struct pwm_chip *chip;
+	struct clk *clk;
+	int ret;
+
+	chip = devm_pwmchip_alloc(dev, SG2042_PWM_CHANNELNUM, sizeof(*ddata));
+	if (IS_ERR(chip))
+		return PTR_ERR(chip);
+	ddata = pwmchip_get_drvdata(chip);
+
+	ddata->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(ddata->base))
+		return PTR_ERR(ddata->base);
+
+	clk = devm_clk_get_enabled(dev, "apb");
+	if (IS_ERR(clk))
+		return dev_err_probe(dev, PTR_ERR(clk), "Failed to get base clk\n");
+
+	ret = devm_clk_rate_exclusive_get(dev, clk);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to get exclusive rate\n");
+
+	ddata->clk_rate_hz = clk_get_rate(clk);
+	/* period = PERIOD * NSEC_PER_SEC / clk_rate_hz */
+	if (!ddata->clk_rate_hz || ddata->clk_rate_hz > NSEC_PER_SEC)
+		return dev_err_probe(dev, -EINVAL,
+				     "Invalid clock rate: %lu\n", ddata->clk_rate_hz);
+
+	rst = devm_reset_control_get_optional_shared_deasserted(dev, NULL);
+	if (IS_ERR(rst))
+		return dev_err_probe(dev, PTR_ERR(rst), "Failed to get reset\n");
+
+	chip->ops = &pwm_sg2042_ops;
+	chip->atomic = true;
+
+	ret = devm_pwmchip_add(dev, chip);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Failed to register PWM chip\n");
+
+	return 0;
+}
+
+static struct platform_driver pwm_sg2042_driver = {
+	.driver	= {
+		.name = "sg2042-pwm",
+		.of_match_table = sg2042_pwm_ids,
+	},
+	.probe = pwm_sg2042_probe,
+};
+module_platform_driver(pwm_sg2042_driver);
+
+MODULE_AUTHOR("Chen Wang");
+MODULE_DESCRIPTION("Sophgo SG2042 PWM driver");
+MODULE_LICENSE("GPL");
--- a/drivers/pwm/pwm-stmpe.c
+++ b/drivers/pwm/pwm-stmpe.c
@@ -326,12 +326,33 @@ static int __init stmpe_pwm_probe(struct platform_device *pdev)
 		return ret;
 	}

+	platform_set_drvdata(pdev, chip);
+
 	return 0;
 }

-static struct platform_driver stmpe_pwm_driver = {
+static void __exit stmpe_pwm_remove(struct platform_device *pdev)
+{
+	struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
+	struct pwm_chip *chip = platform_get_drvdata(pdev);
+
+	pwmchip_remove(chip);
+	stmpe_disable(stmpe, STMPE_BLOCK_PWM);
+}
+
+/*
+ * stmpe_pwm_remove() lives in .exit.text. For drivers registered via
+ * module_platform_driver_probe() this is ok because they cannot get unbound at
+ * runtime. So mark the driver struct with __refdata to prevent modpost
+ * triggering a section mismatch warning.
+ */
+static struct platform_driver stmpe_pwm_driver __refdata = {
 	.driver = {
 		.name = "stmpe-pwm",
 	},
+	.remove = __exit_p(stmpe_pwm_remove),
 };
-builtin_platform_driver_probe(stmpe_pwm_driver, stmpe_pwm_probe);
+module_platform_driver_probe(stmpe_pwm_driver, stmpe_pwm_probe);
+
+MODULE_DESCRIPTION("STMPE expander PWM");
+MODULE_LICENSE("GPL");
--- a/include/linux/pwm.h
+++ b/include/linux/pwm.h
@@ -379,7 +379,7 @@ static inline void pwmchip_set_drvdata(struct pwm_chip *chip, void *data)
 	dev_set_drvdata(&chip->dev, data);
 }

-#if IS_ENABLED(CONFIG_PWM)
+#if IS_REACHABLE(CONFIG_PWM)

 /* PWM consumer APIs */
 int pwm_round_waveform_might_sleep(struct pwm_device *pwm, struct pwm_waveform *wf);
@@ -661,7 +661,7 @@ struct pwm_lookup {
 	PWM_LOOKUP_WITH_MODULE(_provider, _index, _dev_id, _con_id, _period, \
 			       _polarity, NULL)

-#if IS_ENABLED(CONFIG_PWM)
+#if IS_REACHABLE(CONFIG_PWM)
 void pwm_add_table(struct pwm_lookup *table, size_t num);
 void pwm_remove_table(struct pwm_lookup *table, size_t num);
 #else