Enable suspend/resume on Pi 5

Documentation/devicetree/bindings/net/bluetooth/brcm,bluetooth.yaml

@@ -109,6 +109,13 @@ properties:
       if the device's initial baud rate in normal mode is not supported by the
       host or if the device requires autobaud mode startup before loading FW.
 
+  brcm,power-off-in-suspend:
+    type: boolean
+    description:
+      The controller's supply is not maintained while the system is in a sleep
+      state; the controller loses its firmware and its entire configuration
+      across a suspend/resume cycle.
+
   interrupts:
     items:
       - description: Handle to the line HOST_WAKE used to wake

arch/arm/boot/dts/overlays/README

@@ -3992,6 +3992,8 @@ Params: l1ss                    Enable RC ASPM L1 sub-state support. Requires
                                 requires DMA and MSI addresses to be 32bit.
         mmio-hi                 Move the start of outbound 32bit addresses to
                                 2GB and expand 64bit outbound space to 14GB.
+        no-pwr-ctrl             Disable the regulator on the PCIe 3v3 supply.
+                                This leaves it always enabled.
 
 
 [ The pcf2127-rtc overlay has been deleted. See i2c-rtc. ]

arch/arm/boot/dts/overlays/pciex1-compat-pi5-overlay.dts

@@ -51,10 +51,22 @@
 		};
 	};
 
+	/*
+	 * Disable the regulator on the PCIe 3v3 supply.
+	 * Its is enabled by default by the firmware.
+	 */
+	fragment@4 {
+		target = <&pcie1_3v3>;
+		__dormant__ {
+			status = "disabled";
+		};
+	};
+
 	__overrides__ {
 		l1ss = <0>, "+0";
 		no-l0s = <0>, "+1";
 		no-mip = <0>, "+2";
 		mmio-hi = <0>, "+3";
+		no-pwr-ctrl = <0>, "+4";
 	};
 };

arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b.dts

@@ -101,6 +101,17 @@
 		gpio = <&rp1_gpio 46 0>;  // CD1_IO0_MICCLK, to MIPI 1 connector
 	};
 
+	pcie1_3v3: pcie1_3v3 {
+		compatible = "regulator-fixed";
+		regulator-name = "pcie1-3v3";
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+		regulator-boot-on;
+		enable-active-high;
+		gpio = <&rp1_gpio 28 GPIO_ACTIVE_HIGH>;  // PCIE_RP1_WAKE
+		startup-delay-us = <20000>;
+	};
+
 	cam_dummy_reg: cam_dummy_reg {
 		compatible = "regulator-fixed";
 		regulator-name = "cam-dummy-reg";
@@ -125,6 +136,24 @@ rp1_target: &pcie2 {
 
 &pcie1 {
 	brcm,fifo-qos-map = /bits/ 8 <3 3 3 3>;
+
+	/*
+	 * Hack to get linux to probe this pcie after pcie2.
+	 * The pcie-brcmstb driver does not defer probe if
+	 * the regulator is not found yet. This forces pcie1
+	 * to be probed after pcie2 so that the regulator
+	 * is found.
+	 */
+	vpcie3v3-supply = <&pcie1_3v3>;
+
+	pci@0,0 {
+		device_type = "pci";
+		reg = <0 0 0 0 0>;
+		#address-cells = <3>;
+		#size-cells = <2>;
+		ranges;
+		vpcie3v3-supply = <&pcie1_3v3>;
+	};
 };
 
 // The system SPI for the bootloader EEPROM
@@ -374,6 +403,7 @@ dpi_16bit_gpio2:        &rp1_dpi_16bit_gpio2        { };
 		compatible = "brcm,bcm43438-bt";
 		max-speed = <3000000>;
 		shutdown-gpios = <&gio 29 GPIO_ACTIVE_HIGH>;
+		brcm,power-off-in-suspend;
 		local-bd-address = [ 00 00 00 00 00 00 ];
 	};
 };
@@ -426,6 +456,7 @@ dpi_16bit_gpio2:        &rp1_dpi_16bit_gpio2        { };
 	vmmc-supply = <&wl_on_reg>;
 	sd-uhs-ddr50;
 	non-removable;
+	cap-power-off-card;
 	status = "okay";
 	#address-cells = <1>;
 	#size-cells = <0>;

arch/arm64/boot/dts/broadcom/bcm2712-rpi-cm5.dtsi

@@ -359,6 +359,7 @@ dpi_16bit_gpio2:        &rp1_dpi_16bit_gpio2        { };
 		compatible = "brcm,bcm43438-bt";
 		max-speed = <3000000>;
 		shutdown-gpios = <&gio 29 GPIO_ACTIVE_HIGH>;
+		brcm,power-off-in-suspend;
 		local-bd-address = [ 00 00 00 00 00 00 ];
 	};
 };
@@ -411,6 +412,7 @@ dpi_16bit_gpio2:        &rp1_dpi_16bit_gpio2        { };
 	vmmc-supply = <&wl_on_reg>;
 	sd-uhs-ddr50;
 	non-removable;
+	cap-power-off-card;
 	status = "okay";
 	#address-cells = <1>;
 	#size-cells = <0>;

arch/arm64/boot/dts/broadcom/bcm2712-rpi-cm5io.dtsi

@@ -1,5 +1,38 @@
 // SPDX-License-Identifier: GPL-2.0
 
+/ {
+	pcie1_3v3: pcie1_3v3 {
+		compatible = "regulator-fixed";
+		regulator-name = "pcie1-3v3";
+		regulator-min-microvolt = <3300000>;
+		regulator-max-microvolt = <3300000>;
+		regulator-boot-on;
+		enable-active-high;
+		gpio = <&rp1_gpio 28 GPIO_ACTIVE_HIGH>;  // PCIE_PWR_EN
+		startup-delay-us = <20000>;
+	};
+};
+
+&pcie1 {
+	/*
+	 * Hack to get linux to probe this pcie after pcie2.
+	 * The pcie-brcmstb driver does not defer probe if
+	 * the regulator is not found yet. This forces pcie1
+	 * to be probed after pcie2 so that the regulator
+	 * is found.
+	 */
+	vpcie3v3-supply = <&pcie1_3v3>;
+
+	pci@0,0 {
+		device_type = "pci";
+		reg = <0 0 0 0 0>;
+		#address-cells = <3>;
+		#size-cells = <2>;
+		ranges;
+		vpcie3v3-supply = <&pcie1_3v3>;
+	};
+};
+
 i2c_csi_dsi1: &i2c0 { // Note: This is for CAM/DISP 1 connector
 	symlink = "i2c-11";
 };

arch/arm64/configs/bcm2712_defconfig

@@ -50,7 +50,6 @@ CONFIG_ARM64_ERRATUM_2441009=y
 CONFIG_ARM64_16K_PAGES=y
 CONFIG_ARM64_VA_BITS_47=y
 CONFIG_NR_CPUS=4
-CONFIG_HOTPLUG_CPU=y
 CONFIG_NUMA=y
 CONFIG_COMPAT=y
 CONFIG_ARMV8_DEPRECATED=y
@@ -59,9 +58,11 @@ CONFIG_CP15_BARRIER_EMULATION=y
 CONFIG_SETEND_EMULATION=y
 CONFIG_RANDOMIZE_BASE=y
 CONFIG_CMDLINE="console=ttyAMA0,115200 kgdboc=ttyAMA0,115200 root=/dev/mmcblk0p2 rootfstype=ext4 rootwait"
-# CONFIG_SUSPEND is not set
-CONFIG_PM=y
+CONFIG_HIBERNATION=y
 CONFIG_PM_DEBUG=y
+CONFIG_DPM_WATCHDOG=y
+CONFIG_DPM_WATCHDOG_TIMEOUT=30
+CONFIG_DPM_WATCHDOG_WARNING_TIMEOUT=5
 CONFIG_CPU_IDLE=y
 CONFIG_CPU_FREQ=y
 CONFIG_CPU_FREQ_STAT=y

drivers/bluetooth/hci_bcm.c

@@ -26,6 +26,7 @@
 #include <linux/dmi.h>
 #include <linux/pm_runtime.h>
 #include <linux/serdev.h>
+#include <linux/workqueue.h>
 
 #include <net/bluetooth/bluetooth.h>
 #include <net/bluetooth/hci_core.h>
@@ -107,6 +108,8 @@ struct bcm_device_data {
  * @no_uart_clock_set: UART clock set command for >3Mbps mode is unavailable
  * @pcm_int_params: keep the initial PCM configuration
  * @use_autobaud_mode: start Bluetooth device in autobaud mode
+ * @power_off_in_suspend: controller loses power during a system suspend, so
+ *	the device is reprobed on resume
  * @max_autobaud_speed: max baudrate supported by device in autobaud mode
  */
 struct bcm_device {
@@ -147,6 +150,7 @@ struct bcm_device {
 	bool			drive_rts_on_open;
 	bool			no_uart_clock_set;
 	bool			use_autobaud_mode;
+	bool			power_off_in_suspend;
 	u8			pcm_int_params[5];
 	u32			max_autobaud_speed;
 };
@@ -159,6 +163,36 @@ struct bcm_data {
 	struct bcm_device	*dev;
 };
 
+/* True when the controller will be powered off across a system suspend and
+ * rebuilt by a reprobe. Runtime PM is switched off for these devices, so the
+ * runtime callbacks cannot race the suspend path.
+ */
+static bool bcm_powers_off_in_suspend(const struct bcm_device *bdev)
+{
+	return IS_ENABLED(CONFIG_PM_SLEEP) && bdev &&
+	       bdev->power_off_in_suspend && bdev->hu && bdev->hu->serdev;
+}
+
+struct bcm_reprobe {
+	struct device *dev;
+	struct work_struct work;
+};
+
+static void bcm_reprobe_worker(struct work_struct *work)
+{
+	struct bcm_reprobe *reprobe =
+		container_of(work, struct bcm_reprobe, work);
+	int ret;
+
+	ret = device_reprobe(reprobe->dev);
+	if (ret && ret != -EPROBE_DEFER)
+		dev_err(reprobe->dev, "Reprobe error %d\n", ret);
+
+	put_device(reprobe->dev);
+	kfree(reprobe);
+	module_put(THIS_MODULE);
+}
+
 /* List of BCM BT UART devices */
 static DEFINE_MUTEX(bcm_device_lock);
 static LIST_HEAD(bcm_device_list);
@@ -485,6 +519,12 @@ static int bcm_open(struct hci_uart *hu)
 
 out:
 	if (bcm->dev) {
+		/* Since bcm_resume() reprobes the device, the suspend handling
+		 * done by the hci_suspend_notifier is not necessary.
+		 */
+		if (bcm_powers_off_in_suspend(bcm->dev))
+			set_bit(HCI_UART_NO_SUSPEND_NOTIFIER, &hu->flags);
+
 		if (bcm->dev->use_autobaud_mode)
 			hci_uart_set_flow_control(hu, false);	/* Assert BT_UART_CTS_N */
 		else if (bcm->dev->drive_rts_on_open)
@@ -546,6 +586,7 @@ static int bcm_close(struct hci_uart *hu)
 
 	if (bdev) {
 		if (IS_ENABLED(CONFIG_PM) && bdev->irq_acquired) {
+			bdev->irq_acquired = false;
 			devm_free_irq(bdev->dev, bdev->irq, bdev);
 			device_init_wakeup(bdev->dev, false);
 			pm_runtime_disable(bdev->dev);
@@ -646,7 +687,7 @@ static int bcm_setup(struct hci_uart *hu)
 	if (hci_test_quirk(hu->hdev, HCI_QUIRK_INVALID_BDADDR))
 		hci_set_quirk(hu->hdev, HCI_QUIRK_USE_BDADDR_PROPERTY);
 
-	if (!bcm_request_irq(bcm))
+	if (!bcm_powers_off_in_suspend(bcm->dev) && !bcm_request_irq(bcm))
 		err = bcm_setup_sleep(hu);
 
 	return err;
@@ -825,6 +866,25 @@ static int bcm_suspend(struct device *dev)
 
 	bt_dev_dbg(bdev, "suspend: is_suspended %d", bdev->is_suspended);
 
+	/* The controller loses power across the suspend and bcm_resume()
+	 * reprobes it, so there is no state here worth preserving. Stop the
+	 * UART and drive the controller off, as h5_btrtl_suspend() does.
+	 */
+	if (bcm_powers_off_in_suspend(bdev)) {
+		struct hci_dev *hdev = bdev->hu->hdev;
+
+		/* Wait for power_on before suspending. bcm_setup causes
+		 * a timeout if a suspend occurs duriung it
+		 */
+		if (hdev)
+			flush_work(&hdev->power_on);
+
+		hci_uart_set_flow_control(bdev->hu, true);
+		bcm_gpio_set_power(bdev, false);
+
+		return 0;
+	}
+
 	/*
 	 * When used with a device instantiated as platform_device, bcm_suspend
 	 * can be called at any time as long as the platform device is bound,
@@ -859,6 +919,23 @@ static int bcm_resume(struct device *dev)
 
 	bt_dev_dbg(bdev, "resume: is_suspended %d", bdev->is_suspended);
 
+	/* The device has lost all of its firmware and state so reprobe it. */
+	if (bcm_powers_off_in_suspend(bdev)) {
+		struct bcm_reprobe *reprobe;
+
+		reprobe = kzalloc(sizeof(*reprobe), GFP_KERNEL);
+		if (!reprobe)
+			return -ENOMEM;
+
+		__module_get(THIS_MODULE);
+
+		INIT_WORK(&reprobe->work, bcm_reprobe_worker);
+		reprobe->dev = get_device(bdev->dev);
+		queue_work(system_long_wq, &reprobe->work);
+
+		return 0;
+	}
+
 	/*
 	 * When used with a device instantiated as platform_device, bcm_resume
 	 * can be called at any time as long as platform device is bound,
@@ -1229,6 +1306,8 @@ static int bcm_of_probe(struct bcm_device *bdev)
 {
 	bdev->use_autobaud_mode = device_property_read_bool(bdev->dev,
 							    "brcm,requires-autobaud-mode");
+	bdev->power_off_in_suspend = device_property_read_bool(bdev->dev,
+							       "brcm,power-off-in-suspend");
 	device_property_read_u32(bdev->dev, "max-speed", &bdev->oper_speed);
 	device_property_read_u8_array(bdev->dev, "brcm,bt-pcm-int-params",
 				      bdev->pcm_int_params, 5);

drivers/gpio/gpio-brcmstb.c

@@ -10,6 +10,7 @@
 #include <linux/irqchip/chained_irq.h>
 #include <linux/interrupt.h>
 #include <linux/platform_device.h>
+#include <linux/pm.h>
 #include <linux/string_choices.h>
 
 enum gio_reg_index {
@@ -576,8 +577,7 @@ static int brcmstb_gpio_resume(struct device *dev)
 #endif /* CONFIG_PM_SLEEP */
 
 static const struct dev_pm_ops brcmstb_gpio_pm_ops = {
-	.suspend_noirq	= brcmstb_gpio_suspend,
-	.resume_noirq = brcmstb_gpio_resume,
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(brcmstb_gpio_suspend, brcmstb_gpio_resume)
 };
 
 static int brcmstb_gpio_probe(struct platform_device *pdev)