Raspberry Pi driver updates for v5.13:

- Fix-up all RPi firmware drivers so as for unbind to happen in an orderly fashion - Support for RPi's PoE hat PWM bus -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEErOkkGDHCg2EbPcGjlfZmHno8x/4FAmBY1LwACgkQlfZmHno8 x/6PjwgAuB0fgmN08RpGdyQWpsw7XUd56/g/92BtQ/p87khI9VP3ay8q+1AYGSxL jMhSpTu6FOyhyc3y129dtoJDUslsUh5vrXqz3S1niEyYf3CHLjcyc/JPky5/HWJN HlVwOowqLBKxVoX6AWGqRWc/axxtm9uMWeK2yiI4LYgDvq7DWhENSp4xwtffLt4q Tg5dcqw5PbCWA2npkabnZjhLuDt1XRaLb455yn9P8tCRiqwf5fQ/8zjfcJLNhYTV Fy/yrXyBg8RnUOlFviSbtVG0ey1BUdWkxbBd0Vxrh9iw/z+EVQdcN0DZGsKcWsXy bK7R2sdCHmV9hjgfc4+mLPKwWhyApQ== =bA9X -----END PGP SIGNATURE----- Merge tag 'rpi-poe-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/nsaenz/linux-rpi into arm/drivers Raspberry Pi driver updates for v5.13: - Fix-up all RPi firmware drivers so as for unbind to happen in an orderly fashion - Support for RPi's PoE hat PWM bus * tag 'rpi-poe-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/nsaenz/linux-rpi: pwm: Add Raspberry Pi Firmware based PWM bus dt-bindings: pwm: Add binding for RPi firmware PWM bus input: raspberrypi-ts: Release firmware handle when not needed staging: vchiq: Release firmware handle on unbind soc: bcm: raspberrypi-power: Release firmware handle on unbind reset: raspberrypi: Release firmware handle on unbind gpio: raspberrypi-exp: Release firmware handle on unbind clk: bcm: rpi: Release firmware handle on unbind firmware: raspberrypi: Introduce devm_rpi_firmware_get() firmware: raspberrypi: Keep count of all consumers Link: https://lore.kernel.org/r/20210322174232.29549-1-nsaenz@kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-09-29 05:44:11 +00:00 · 2021-04-01 20:56:49 +02:00 · 2021-04-01 20:56:49 +02:00 · 7da68c64bc
commit 7da68c64bc
parent 56a6867bee 79caa362ea
13 changed files with 331 additions and 9 deletions
--- a/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml
+++ b/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml
@ -64,6 +64,21 @@ properties:
      - compatible
      - "#reset-cells"

+  pwm:
+    type: object
+
+    properties:
+      compatible:
+        const: raspberrypi,firmware-poe-pwm
+
+      "#pwm-cells":
+        # See pwm.yaml in this directory for a description of the cells format.
+        const: 2
+
+    required:
+      - compatible
+      - "#pwm-cells"
+
    additionalProperties: false

 required:
@ -87,5 +102,10 @@ examples:
            compatible = "raspberrypi,firmware-reset";
            #reset-cells = <1>;
        };
+
+        pwm: pwm {
+            compatible = "raspberrypi,firmware-poe-pwm";
+            #pwm-cells = <2>;
+        };
    };
 ...
--- a/drivers/clk/bcm/clk-raspberrypi.c
+++ b/drivers/clk/bcm/clk-raspberrypi.c
@ -314,7 +314,7 @@ static int raspberrypi_clk_probe(struct platform_device *pdev)
 		return -ENOENT;
 	}

-	firmware = rpi_firmware_get(firmware_node);
+	firmware = devm_rpi_firmware_get(&pdev->dev, firmware_node);
 	of_node_put(firmware_node);
 	if (!firmware)
 		return -EPROBE_DEFER;
--- a/drivers/firmware/raspberrypi.c
+++ b/drivers/firmware/raspberrypi.c
@ -7,6 +7,7 @@
 */

 #include <linux/dma-mapping.h>
+#include <linux/kref.h>
 #include <linux/mailbox_client.h>
 #include <linux/module.h>
 #include <linux/of_platform.h>
@ -27,6 +28,8 @@ struct rpi_firmware {
 	struct mbox_chan *chan; /* The property channel. */
 	struct completion c;
 	u32 enabled;
+
+	struct kref consumers;
 };

 static DEFINE_MUTEX(transaction_lock);
@ -225,12 +228,38 @@ static void rpi_register_clk_driver(struct device *dev)
 						-1, NULL, 0);
 }

+static void rpi_firmware_delete(struct kref *kref)
+{
+	struct rpi_firmware *fw = container_of(kref, struct rpi_firmware,
+					       consumers);
+
+	mbox_free_channel(fw->chan);
+	kfree(fw);
+}
+
+void rpi_firmware_put(struct rpi_firmware *fw)
+{
+	kref_put(&fw->consumers, rpi_firmware_delete);
+}
+EXPORT_SYMBOL_GPL(rpi_firmware_put);
+
+static void devm_rpi_firmware_put(void *data)
+{
+	struct rpi_firmware *fw = data;
+
+	rpi_firmware_put(fw);
+}
+
 static int rpi_firmware_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct rpi_firmware *fw;

-	fw = devm_kzalloc(dev, sizeof(*fw), GFP_KERNEL);
+	/*
+	 * Memory will be freed by rpi_firmware_delete() once all users have
+	 * released their firmware handles. Don't use devm_kzalloc() here.
+	 */
+	fw = kzalloc(sizeof(*fw), GFP_KERNEL);
 	if (!fw)
 		return -ENOMEM;

@ -247,6 +276,7 @@ static int rpi_firmware_probe(struct platform_device *pdev)
 	}

 	init_completion(&fw->c);
+	kref_init(&fw->consumers);

 	platform_set_drvdata(pdev, fw);

@ -275,7 +305,8 @@ static int rpi_firmware_remove(struct platform_device *pdev)
 	rpi_hwmon = NULL;
 	platform_device_unregister(rpi_clk);
 	rpi_clk = NULL;
-	mbox_free_channel(fw->chan);
+
+	rpi_firmware_put(fw);

 	return 0;
 }
@ -284,19 +315,51 @@ static int rpi_firmware_remove(struct platform_device *pdev)
 * rpi_firmware_get - Get pointer to rpi_firmware structure.
 * @firmware_node:    Pointer to the firmware Device Tree node.
 *
+ * The reference to rpi_firmware has to be released with rpi_firmware_put().
+ *
 * Returns NULL is the firmware device is not ready.
 */
 struct rpi_firmware *rpi_firmware_get(struct device_node *firmware_node)
 {
 	struct platform_device *pdev = of_find_device_by_node(firmware_node);
+	struct rpi_firmware *fw;

 	if (!pdev)
 		return NULL;

-	return platform_get_drvdata(pdev);
+	fw = platform_get_drvdata(pdev);
+	if (!fw)
+		return NULL;
+
+	if (!kref_get_unless_zero(&fw->consumers))
+		return NULL;
+
+	return fw;
 }
 EXPORT_SYMBOL_GPL(rpi_firmware_get);

+/**
+ * devm_rpi_firmware_get - Get pointer to rpi_firmware structure.
+ * @firmware_node:    Pointer to the firmware Device Tree node.
+ *
+ * Returns NULL is the firmware device is not ready.
+ */
+struct rpi_firmware *devm_rpi_firmware_get(struct device *dev,
+					   struct device_node *firmware_node)
+{
+	struct rpi_firmware *fw;
+
+	fw = rpi_firmware_get(firmware_node);
+	if (!fw)
+		return NULL;
+
+	if (devm_add_action_or_reset(dev, devm_rpi_firmware_put, fw))
+		return NULL;
+
+	return fw;
+}
+EXPORT_SYMBOL_GPL(devm_rpi_firmware_get);
+
 static const struct of_device_id rpi_firmware_of_match[] = {
 	{ .compatible = "raspberrypi,bcm2835-firmware", },
 	{},
--- a/drivers/gpio/gpio-raspberrypi-exp.c
+++ b/drivers/gpio/gpio-raspberrypi-exp.c
@ -208,7 +208,7 @@ static int rpi_exp_gpio_probe(struct platform_device *pdev)
 		return -ENOENT;
 	}

-	fw = rpi_firmware_get(fw_node);
+	fw = devm_rpi_firmware_get(&pdev->dev, fw_node);
 	of_node_put(fw_node);
 	if (!fw)
 		return -EPROBE_DEFER;
--- a/drivers/input/touchscreen/raspberrypi-ts.c
+++ b/drivers/input/touchscreen/raspberrypi-ts.c
@ -160,7 +160,7 @@ static int rpi_ts_probe(struct platform_device *pdev)
 	touchbuf = (u32)ts->fw_regs_phys;
 	error = rpi_firmware_property(fw, RPI_FIRMWARE_FRAMEBUFFER_SET_TOUCHBUF,
 				      &touchbuf, sizeof(touchbuf));
-
+	rpi_firmware_put(fw);
 	if (error || touchbuf != 0) {
 		dev_warn(dev, "Failed to set touchbuf, %d\n", error);
 		return error;
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@ -423,6 +423,15 @@ config PWM_PXA
 	  To compile this driver as a module, choose M here: the module
 	  will be called pwm-pxa.

+config PWM_RASPBERRYPI_POE
+	tristate "Raspberry Pi Firwmware PoE Hat PWM support"
+	# Make sure not 'y' when RASPBERRYPI_FIRMWARE is 'm'. This can only
+	# happen when COMPILE_TEST=y, hence the added !RASPBERRYPI_FIRMWARE.
+	depends on RASPBERRYPI_FIRMWARE || (COMPILE_TEST && !RASPBERRYPI_FIRMWARE)
+	help
+	  Enable Raspberry Pi firmware controller PWM bus used to control the
+	  official RPI PoE hat
+
 config PWM_RCAR
 	tristate "Renesas R-Car PWM support"
 	depends on ARCH_RENESAS || COMPILE_TEST
--- a/drivers/pwm/Makefile
+++ b/drivers/pwm/Makefile
@ -38,6 +38,7 @@ obj-$(CONFIG_PWM_MXS)		+= pwm-mxs.o
 obj-$(CONFIG_PWM_OMAP_DMTIMER)	+= pwm-omap-dmtimer.o
 obj-$(CONFIG_PWM_PCA9685)	+= pwm-pca9685.o
 obj-$(CONFIG_PWM_PXA)		+= pwm-pxa.o
+obj-$(CONFIG_PWM_RASPBERRYPI_POE)	+= pwm-raspberrypi-poe.o
 obj-$(CONFIG_PWM_RCAR)		+= pwm-rcar.o
 obj-$(CONFIG_PWM_RENESAS_TPU)	+= pwm-renesas-tpu.o
 obj-$(CONFIG_PWM_ROCKCHIP)	+= pwm-rockchip.o
--- a/drivers/pwm/pwm-raspberrypi-poe.c
+++ b/drivers/pwm/pwm-raspberrypi-poe.c
@ -0,0 +1,206 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2021 Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
+ * For more information on Raspberry Pi's PoE hat see:
+ * https://www.raspberrypi.org/products/poe-hat/
+ *
+ * Limitations:
+ *  - No disable bit, so a disabled PWM is simulated by duty_cycle 0
+ *  - Only normal polarity
+ *  - Fixed 12.5 kHz period
+ *
+ * The current period is completed when HW is reconfigured.
+ */
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+
+#include <soc/bcm2835/raspberrypi-firmware.h>
+#include <dt-bindings/pwm/raspberrypi,firmware-poe-pwm.h>
+
+#define RPI_PWM_MAX_DUTY		255
+#define RPI_PWM_PERIOD_NS		80000 /* 12.5 kHz */
+
+#define RPI_PWM_CUR_DUTY_REG		0x0
+
+struct raspberrypi_pwm {
+	struct rpi_firmware *firmware;
+	struct pwm_chip chip;
+	unsigned int duty_cycle;
+};
+
+struct raspberrypi_pwm_prop {
+	__le32 reg;
+	__le32 val;
+	__le32 ret;
+} __packed;
+
+static inline
+struct raspberrypi_pwm *raspberrypi_pwm_from_chip(struct pwm_chip *chip)
+{
+	return container_of(chip, struct raspberrypi_pwm, chip);
+}
+
+static int raspberrypi_pwm_set_property(struct rpi_firmware *firmware,
+					u32 reg, u32 val)
+{
+	struct raspberrypi_pwm_prop msg = {
+		.reg = cpu_to_le32(reg),
+		.val = cpu_to_le32(val),
+	};
+	int ret;
+
+	ret = rpi_firmware_property(firmware, RPI_FIRMWARE_SET_POE_HAT_VAL,
+				    &msg, sizeof(msg));
+	if (ret)
+		return ret;
+	if (msg.ret)
+		return -EIO;
+
+	return 0;
+}
+
+static int raspberrypi_pwm_get_property(struct rpi_firmware *firmware,
+					u32 reg, u32 *val)
+{
+	struct raspberrypi_pwm_prop msg = {
+		.reg = reg
+	};
+	int ret;
+
+	ret = rpi_firmware_property(firmware, RPI_FIRMWARE_GET_POE_HAT_VAL,
+				    &msg, sizeof(msg));
+	if (ret)
+		return ret;
+	if (msg.ret)
+		return -EIO;
+
+	*val = le32_to_cpu(msg.val);
+
+	return 0;
+}
+
+static void raspberrypi_pwm_get_state(struct pwm_chip *chip,
+				      struct pwm_device *pwm,
+				      struct pwm_state *state)
+{
+	struct raspberrypi_pwm *rpipwm = raspberrypi_pwm_from_chip(chip);
+
+	state->period = RPI_PWM_PERIOD_NS;
+	state->duty_cycle = DIV_ROUND_UP(rpipwm->duty_cycle * RPI_PWM_PERIOD_NS,
+					 RPI_PWM_MAX_DUTY);
+	state->enabled = !!(rpipwm->duty_cycle);
+	state->polarity = PWM_POLARITY_NORMAL;
+}
+
+static int raspberrypi_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+				 const struct pwm_state *state)
+{
+	struct raspberrypi_pwm *rpipwm = raspberrypi_pwm_from_chip(chip);
+	unsigned int duty_cycle;
+	int ret;
+
+	if (state->period < RPI_PWM_PERIOD_NS ||
+	    state->polarity != PWM_POLARITY_NORMAL)
+		return -EINVAL;
+
+	if (!state->enabled)
+		duty_cycle = 0;
+	else if (state->duty_cycle < RPI_PWM_PERIOD_NS)
+		duty_cycle = DIV_ROUND_DOWN_ULL(state->duty_cycle * RPI_PWM_MAX_DUTY,
+						RPI_PWM_PERIOD_NS);
+	else
+		duty_cycle = RPI_PWM_MAX_DUTY;
+
+	if (duty_cycle == rpipwm->duty_cycle)
+		return 0;
+
+	ret = raspberrypi_pwm_set_property(rpipwm->firmware, RPI_PWM_CUR_DUTY_REG,
+					   duty_cycle);
+	if (ret) {
+		dev_err(chip->dev, "Failed to set duty cycle: %pe\n",
+			ERR_PTR(ret));
+		return ret;
+	}
+
+	rpipwm->duty_cycle = duty_cycle;
+
+	return 0;
+}
+
+static const struct pwm_ops raspberrypi_pwm_ops = {
+	.get_state = raspberrypi_pwm_get_state,
+	.apply = raspberrypi_pwm_apply,
+	.owner = THIS_MODULE,
+};
+
+static int raspberrypi_pwm_probe(struct platform_device *pdev)
+{
+	struct device_node *firmware_node;
+	struct device *dev = &pdev->dev;
+	struct rpi_firmware *firmware;
+	struct raspberrypi_pwm *rpipwm;
+	int ret;
+
+	firmware_node = of_get_parent(dev->of_node);
+	if (!firmware_node) {
+		dev_err(dev, "Missing firmware node\n");
+		return -ENOENT;
+	}
+
+	firmware = devm_rpi_firmware_get(&pdev->dev, firmware_node);
+	of_node_put(firmware_node);
+	if (!firmware)
+		return dev_err_probe(dev, -EPROBE_DEFER,
+				     "Failed to get firmware handle\n");
+
+	rpipwm = devm_kzalloc(&pdev->dev, sizeof(*rpipwm), GFP_KERNEL);
+	if (!rpipwm)
+		return -ENOMEM;
+
+	rpipwm->firmware = firmware;
+	rpipwm->chip.dev = dev;
+	rpipwm->chip.ops = &raspberrypi_pwm_ops;
+	rpipwm->chip.base = -1;
+	rpipwm->chip.npwm = RASPBERRYPI_FIRMWARE_PWM_NUM;
+
+	platform_set_drvdata(pdev, rpipwm);
+
+	ret = raspberrypi_pwm_get_property(rpipwm->firmware, RPI_PWM_CUR_DUTY_REG,
+					   &rpipwm->duty_cycle);
+	if (ret) {
+		dev_err(dev, "Failed to get duty cycle: %pe\n", ERR_PTR(ret));
+		return ret;
+	}
+
+	return pwmchip_add(&rpipwm->chip);
+}
+
+static int raspberrypi_pwm_remove(struct platform_device *pdev)
+{
+	struct raspberrypi_pwm *rpipwm = platform_get_drvdata(pdev);
+
+	return pwmchip_remove(&rpipwm->chip);
+}
+
+static const struct of_device_id raspberrypi_pwm_of_match[] = {
+	{ .compatible = "raspberrypi,firmware-poe-pwm", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, raspberrypi_pwm_of_match);
+
+static struct platform_driver raspberrypi_pwm_driver = {
+	.driver = {
+		.name = "raspberrypi-poe-pwm",
+		.of_match_table = raspberrypi_pwm_of_match,
+	},
+	.probe = raspberrypi_pwm_probe,
+	.remove = raspberrypi_pwm_remove,
+};
+module_platform_driver(raspberrypi_pwm_driver);
+
+MODULE_AUTHOR("Nicolas Saenz Julienne <nsaenzjulienne@suse.de>");
+MODULE_DESCRIPTION("Raspberry Pi Firmware Based PWM Bus Driver");
+MODULE_LICENSE("GPL v2");
--- a/drivers/reset/reset-raspberrypi.c
+++ b/drivers/reset/reset-raspberrypi.c
@ -82,7 +82,7 @@ static int rpi_reset_probe(struct platform_device *pdev)
 		return -ENOENT;
 	}

-	fw = rpi_firmware_get(np);
+	fw = devm_rpi_firmware_get(&pdev->dev, np);
 	of_node_put(np);
 	if (!fw)
 		return -EPROBE_DEFER;
--- a/drivers/soc/bcm/raspberrypi-power.c
+++ b/drivers/soc/bcm/raspberrypi-power.c
@ -177,7 +177,7 @@ static int rpi_power_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}

-	rpi_domains->fw = rpi_firmware_get(fw_np);
+	rpi_domains->fw = devm_rpi_firmware_get(&pdev->dev, fw_np);
 	of_node_put(fw_np);
 	if (!rpi_domains->fw)
 		return -EPROBE_DEFER;
--- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
+++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c
@ -2734,7 +2734,7 @@ static int vchiq_probe(struct platform_device *pdev)
 		return -ENOENT;
 	}

-	drvdata->fw = rpi_firmware_get(fw_node);
+	drvdata->fw = devm_rpi_firmware_get(&pdev->dev, fw_node);
 	of_node_put(fw_node);
 	if (!drvdata->fw)
 		return -EPROBE_DEFER;
--- a/include/dt-bindings/pwm/raspberrypi,firmware-poe-pwm.h
+++ b/include/dt-bindings/pwm/raspberrypi,firmware-poe-pwm.h
@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2020 Nicolas Saenz Julienne
+ * Author: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
+ */
+
+#ifndef _DT_BINDINGS_RASPBERRYPI_FIRMWARE_PWM_H
+#define _DT_BINDINGS_RASPBERRYPI_FIRMWARE_PWM_H
+
+#define RASPBERRYPI_FIRMWARE_PWM_POE		0
+#define RASPBERRYPI_FIRMWARE_PWM_NUM		1
+
+#endif
--- a/include/soc/bcm2835/raspberrypi-firmware.h
+++ b/include/soc/bcm2835/raspberrypi-firmware.h
@ -140,7 +140,10 @@ int rpi_firmware_property(struct rpi_firmware *fw,
 			  u32 tag, void *data, size_t len);
 int rpi_firmware_property_list(struct rpi_firmware *fw,
 			       void *data, size_t tag_size);
+void rpi_firmware_put(struct rpi_firmware *fw);
 struct rpi_firmware *rpi_firmware_get(struct device_node *firmware_node);
+struct rpi_firmware *devm_rpi_firmware_get(struct device *dev,
+					   struct device_node *firmware_node);
 #else
 static inline int rpi_firmware_property(struct rpi_firmware *fw, u32 tag,
 					void *data, size_t len)
@ -154,10 +157,17 @@ static inline int rpi_firmware_property_list(struct rpi_firmware *fw,
 	return -ENOSYS;
 }

+static inline void rpi_firmware_put(struct rpi_firmware *fw) { }
 static inline struct rpi_firmware *rpi_firmware_get(struct device_node *firmware_node)
 {
 	return NULL;
 }
+
+static inline struct rpi_firmware *devm_rpi_firmware_get(struct device *dev,
+					struct device_node *firmware_node)
+{
+	return NULL;
+}
 #endif

 #endif /* __SOC_RASPBERRY_FIRMWARE_H__ */