[PATCH v3 0/5] BCM2835 PM driver (MFD version respin)

[PATCH v3 0/5] BCM2835 PM driver (MFD version respin)

[Eric Anholt]

Guenter had some minor changes to patch #2, which I've done in this
version.

Eric Anholt (5):
  dt-bindings: soc: Add a new binding for the BCM2835 PM node.
  bcm2835-pm: Move bcm2835-watchdog's DT probe to an MFD.
  soc: bcm: bcm2835-pm: Add support for power domains under a new
    binding.
  ARM: bcm283x: Extend the WDT DT node out to cover the whole PM block.
  ARM: bcm283x: Switch V3D over to using the PM driver instead of
    firmware.

 .../bindings/soc/bcm/brcm,bcm2835-pm.txt      |  42 ++
 arch/arm/boot/dts/bcm2835-rpi.dtsi            |   4 -
 arch/arm/boot/dts/bcm283x.dtsi                |  16 +-
 arch/arm/mach-bcm/Kconfig                     |   1 +
 drivers/mfd/Makefile                          |   1 +
 drivers/mfd/bcm2835-pm.c                      |  92 +++
 drivers/soc/bcm/Kconfig                       |  11 +
 drivers/soc/bcm/Makefile                      |   1 +
 drivers/soc/bcm/bcm2835-power.c               | 661 ++++++++++++++++++
 drivers/watchdog/bcm2835_wdt.c                |  26 +-
 include/dt-bindings/soc/bcm2835-pm.h          |  28 +
 include/linux/mfd/bcm2835-pm.h                |  14 +
 12 files changed, 873 insertions(+), 24 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-pm.txt
 create mode 100644 drivers/mfd/bcm2835-pm.c
 create mode 100644 drivers/soc/bcm/bcm2835-power.c
 create mode 100644 include/dt-bindings/soc/bcm2835-pm.h
 create mode 100644 include/linux/mfd/bcm2835-pm.h

-- 
2.20.0.rc1

[PATCH v3 1/5] dt-bindings: soc: Add a new binding for the BCM2835 PM node.

[Eric Anholt]

This binding supersedes the bcm2835-pm-wdt binding which only covered
enough to provide a watchdog, but the HW block is actually mostly
about power domains.

Signed-off-by: Eric Anholt <eric@anholt.net>
---
 .../bindings/soc/bcm/brcm,bcm2835-pm.txt      | 42 +++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-pm.txt

diff --git a/Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-pm.txt b/Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-pm.txt
new file mode 100644
index 000000000000..7818d33a158f
--- /dev/null
+++ b/Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-pm.txt
@@ -0,0 +1,42 @@
+BCM2835 PM (Power domains, watchdog)
+
+The PM block controls power domains and some reset lines, and includes
+a watchdog timer.  This binding supersedes the brcm,bcm2835-pm-wdt
+binding which covered some of PM's register range and functionality.
+
+Required properties:
+
+- compatible:		Should be "brcm,bcm2835-pm"
+- reg:			Specifies base physical address and size of the two
+			  register ranges ("PM" and "ASYNC_BRIDGE" in that
+			  order)
+- clocks:		a) v3d: The V3D clock from CPRMAN
+			b) peri_image: The PERI_IMAGE clock from CPRMAN
+			c) h264: The H264 clock from CPRMAN
+			d) isp: The ISP clock from CPRMAN
+- #reset-cells: 	Should be 1.  This property follows the reset controller
+			  bindings[1].
+- #power-domain-cells:	Should be 1.  This property follows the power domain
+			  bindings[2].
+
+Optional properties:
+
+- timeout-sec:	Contains the watchdog timeout in seconds
+
+[1] Documentation/devicetree/bindings/reset/reset.txt
+[2] Documentation/devicetree/bindings/power/power_domain.txt
+
+Example:
+
+pm {
+	compatible = "brcm,bcm2835-pm", "brcm,bcm2835-pm-wdt";
+	#power-domain-cells = <1>;
+	#reset-cells = <1>;
+	reg = <0x7e100000 0x114>,
+	      <0x7e00a000 0x24>;
+	clocks = <&clocks BCM2835_CLOCK_V3D>,
+		 <&clocks BCM2835_CLOCK_PERI_IMAGE>,
+		 <&clocks BCM2835_CLOCK_H264>,
+		 <&clocks BCM2835_CLOCK_ISP>;
+	clock-names = "v3d", "peri_image", "h264", "isp";
+};
-- 
2.20.0.rc1

[PATCH v3 2/5] bcm2835-pm: Move bcm2835-watchdog's DT probe to an MFD.

[Eric Anholt]

The PM block that the wdt driver was binding to actually has multiple
features we want to expose (power domains, reset, watchdog).  Move the
DT attachment to a MFD driver and make WDT probe against MFD.

Signed-off-by: Eric Anholt <eric@anholt.net>
---

v3: don't reset bcm2835_power_off_wdt on remove, drop pm driver's
    empty remove, sort includes, add a "static".

 arch/arm/mach-bcm/Kconfig      |  1 +
 drivers/mfd/Makefile           |  1 +
 drivers/mfd/bcm2835-pm.c       | 64 ++++++++++++++++++++++++++++++++++
 drivers/watchdog/bcm2835_wdt.c | 26 +++++---------
 include/linux/mfd/bcm2835-pm.h | 13 +++++++
 5 files changed, 88 insertions(+), 17 deletions(-)
 create mode 100644 drivers/mfd/bcm2835-pm.c
 create mode 100644 include/linux/mfd/bcm2835-pm.h

diff --git a/arch/arm/mach-bcm/Kconfig b/arch/arm/mach-bcm/Kconfig
index 25aac6ee2ab1..95242c2162a2 100644
--- a/arch/arm/mach-bcm/Kconfig
+++ b/arch/arm/mach-bcm/Kconfig
@@ -167,6 +167,7 @@ config ARCH_BCM2835
 	select BCM2835_TIMER
 	select PINCTRL
 	select PINCTRL_BCM2835
+	select MFD_CORE
 	help
 	  This enables support for the Broadcom BCM2835 and BCM2836 SoCs.
 	  This SoC is used in the Raspberry Pi and Roku 2 devices.
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 12980a4ad460..ee6fb6af655e 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_MFD_88PM805)	+= 88pm805.o 88pm80x.o
 obj-$(CONFIG_MFD_ACT8945A)	+= act8945a.o
 obj-$(CONFIG_MFD_SM501)		+= sm501.o
 obj-$(CONFIG_MFD_ASIC3)		+= asic3.o tmio_core.o
+obj-$(CONFIG_ARCH_BCM2835)	+= bcm2835-pm.o
 obj-$(CONFIG_MFD_BCM590XX)	+= bcm590xx.o
 obj-$(CONFIG_MFD_BD9571MWV)	+= bd9571mwv.o
 cros_ec_core-objs		:= cros_ec.o
diff --git a/drivers/mfd/bcm2835-pm.c b/drivers/mfd/bcm2835-pm.c
new file mode 100644
index 000000000000..53839e6a81e7
--- /dev/null
+++ b/drivers/mfd/bcm2835-pm.c
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PM MFD driver for Broadcom BCM2835
+ *
+ * This driver binds to the PM block and creates the MFD device for
+ * the WDT driver.
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/mfd/bcm2835-pm.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
+
+static const struct mfd_cell bcm2835_pm_devs[] = {
+	{ .name = "bcm2835-wdt" },
+};
+
+static int bcm2835_pm_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct device *dev = &pdev->dev;
+	struct bcm2835_pm *pm;
+
+	pm = devm_kzalloc(dev, sizeof(*pm), GFP_KERNEL);
+	if (!pm)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, pm);
+
+	pm->dev = dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	pm->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(pm->base))
+		return PTR_ERR(pm->base);
+
+	return devm_mfd_add_devices(dev, -1,
+				    bcm2835_pm_devs, ARRAY_SIZE(bcm2835_pm_devs),
+				    NULL, 0, NULL);
+}
+
+static const struct of_device_id bcm2835_pm_of_match[] = {
+	{ .compatible = "brcm,bcm2835-pm-wdt", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, bcm2835_pm_of_match);
+
+static struct platform_driver bcm2835_pm_driver = {
+	.probe		= bcm2835_pm_probe,
+	.driver = {
+		.name =	"bcm2835-pm",
+		.of_match_table = bcm2835_pm_of_match,
+	},
+};
+module_platform_driver(bcm2835_pm_driver);
+
+MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
+MODULE_DESCRIPTION("Driver for Broadcom BCM2835 PM MFD");
+MODULE_LICENSE("GPL");
diff --git a/drivers/watchdog/bcm2835_wdt.c b/drivers/watchdog/bcm2835_wdt.c
index ed05514cc2dc..1834524ae373 100644
--- a/drivers/watchdog/bcm2835_wdt.c
+++ b/drivers/watchdog/bcm2835_wdt.c
@@ -12,6 +12,7 @@
 
 #include <linux/delay.h>
 #include <linux/types.h>
+#include <linux/mfd/bcm2835-pm.h>
 #include <linux/module.h>
 #include <linux/io.h>
 #include <linux/watchdog.h>
@@ -47,6 +48,8 @@ struct bcm2835_wdt {
 	spinlock_t		lock;
 };
 
+static struct bcm2835_wdt *bcm2835_power_off_wdt;
+
 static unsigned int heartbeat;
 static bool nowayout = WATCHDOG_NOWAYOUT;
 
@@ -148,10 +151,7 @@ static struct watchdog_device bcm2835_wdt_wdd = {
  */
 static void bcm2835_power_off(void)
 {
-	struct device_node *np =
-		of_find_compatible_node(NULL, NULL, "brcm,bcm2835-pm-wdt");
-	struct platform_device *pdev = of_find_device_by_node(np);
-	struct bcm2835_wdt *wdt = platform_get_drvdata(pdev);
+	struct bcm2835_wdt *wdt = bcm2835_power_off_wdt;
 	u32 val;
 
 	/*
@@ -169,7 +169,7 @@ static void bcm2835_power_off(void)
 
 static int bcm2835_wdt_probe(struct platform_device *pdev)
 {
-	struct resource *res;
+	struct bcm2835_pm *pm = dev_get_drvdata(pdev->dev.parent);
 	struct device *dev = &pdev->dev;
 	struct bcm2835_wdt *wdt;
 	int err;
@@ -181,10 +181,7 @@ static int bcm2835_wdt_probe(struct platform_device *pdev)
 
 	spin_lock_init(&wdt->lock);
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	wdt->base = devm_ioremap_resource(dev, res);
-	if (IS_ERR(wdt->base))
-		return PTR_ERR(wdt->base);
+	wdt->base = pm->base;
 
 	watchdog_set_drvdata(&bcm2835_wdt_wdd, wdt);
 	watchdog_init_timeout(&bcm2835_wdt_wdd, heartbeat, dev);
@@ -211,8 +208,10 @@ static int bcm2835_wdt_probe(struct platform_device *pdev)
 		return err;
 	}
 
-	if (pm_power_off == NULL)
+	if (pm_power_off == NULL) {
 		pm_power_off = bcm2835_power_off;
+		bcm2835_power_off_wdt = wdt;
+	}
 
 	dev_info(dev, "Broadcom BCM2835 watchdog timer");
 	return 0;
@@ -226,18 +225,11 @@ static int bcm2835_wdt_remove(struct platform_device *pdev)
 	return 0;
 }
 
-static const struct of_device_id bcm2835_wdt_of_match[] = {
-	{ .compatible = "brcm,bcm2835-pm-wdt", },
-	{},
-};
-MODULE_DEVICE_TABLE(of, bcm2835_wdt_of_match);
-
 static struct platform_driver bcm2835_wdt_driver = {
 	.probe		= bcm2835_wdt_probe,
 	.remove		= bcm2835_wdt_remove,
 	.driver = {
 		.name =		"bcm2835-wdt",
-		.of_match_table = bcm2835_wdt_of_match,
 	},
 };
 module_platform_driver(bcm2835_wdt_driver);
diff --git a/include/linux/mfd/bcm2835-pm.h b/include/linux/mfd/bcm2835-pm.h
new file mode 100644
index 000000000000..b7d0ee1feffa
--- /dev/null
+++ b/include/linux/mfd/bcm2835-pm.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+#ifndef BCM2835_MFD_PM_H
+#define BCM2835_MFD_PM_H
+
+#include <linux/regmap.h>
+
+struct bcm2835_pm {
+	struct device *dev;
+	void __iomem *base;
+};
+
+#endif /* BCM2835_MFD_PM_H */
-- 
2.20.0.rc1

[PATCH v3 3/5] soc: bcm: bcm2835-pm: Add support for power domains under a new binding.

[Eric Anholt]

This provides a free software alternative to raspberrypi-power.c's
firmware calls to manage power domains.  It also exposes a reset line,
where previously the vc4 driver had to try to force power off the
domain in order to trigger a reset.

Signed-off-by: Eric Anholt <eric@anholt.net>
---
 drivers/mfd/bcm2835-pm.c             |  36 +-
 drivers/soc/bcm/Kconfig              |  11 +
 drivers/soc/bcm/Makefile             |   1 +
 drivers/soc/bcm/bcm2835-power.c      | 661 +++++++++++++++++++++++++++
 include/dt-bindings/soc/bcm2835-pm.h |  28 ++
 include/linux/mfd/bcm2835-pm.h       |   1 +
 6 files changed, 734 insertions(+), 4 deletions(-)
 create mode 100644 drivers/soc/bcm/bcm2835-power.c
 create mode 100644 include/dt-bindings/soc/bcm2835-pm.h

diff --git a/drivers/mfd/bcm2835-pm.c b/drivers/mfd/bcm2835-pm.c
index 53839e6a81e7..42fe67f1538e 100644
--- a/drivers/mfd/bcm2835-pm.c
+++ b/drivers/mfd/bcm2835-pm.c
@@ -3,7 +3,7 @@
  * PM MFD driver for Broadcom BCM2835
  *
  * This driver binds to the PM block and creates the MFD device for
- * the WDT driver.
+ * the WDT and power drivers.
  */
 
 #include <linux/delay.h>
@@ -21,11 +21,16 @@ static const struct mfd_cell bcm2835_pm_devs[] = {
 	{ .name = "bcm2835-wdt" },
 };
 
+static const struct mfd_cell bcm2835_power_devs[] = {
+	{ .name = "bcm2835-power" },
+};
+
 static int bcm2835_pm_probe(struct platform_device *pdev)
 {
 	struct resource *res;
 	struct device *dev = &pdev->dev;
 	struct bcm2835_pm *pm;
+	int ret;
 
 	pm = devm_kzalloc(dev, sizeof(*pm), GFP_KERNEL);
 	if (!pm)
@@ -39,13 +44,36 @@ static int bcm2835_pm_probe(struct platform_device *pdev)
 	if (IS_ERR(pm->base))
 		return PTR_ERR(pm->base);
 
-	return devm_mfd_add_devices(dev, -1,
-				    bcm2835_pm_devs, ARRAY_SIZE(bcm2835_pm_devs),
-				    NULL, 0, NULL);
+	ret = devm_mfd_add_devices(dev, -1,
+				   bcm2835_pm_devs, ARRAY_SIZE(bcm2835_pm_devs),
+				   NULL, 0, NULL);
+	if (ret)
+		return ret;
+
+	/* We'll use the presence of the AXI ASB regs in the
+	 * bcm2835-pm binding as the key for whether we can reference
+	 * the full PM register range and support power domains.
+	 */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (res) {
+		pm->asb = devm_ioremap_resource(dev, res);
+		if (IS_ERR(pm->asb))
+			return PTR_ERR(pm->asb);
+
+		ret = devm_mfd_add_devices(dev, -1,
+					   bcm2835_power_devs,
+					   ARRAY_SIZE(bcm2835_power_devs),
+					   NULL, 0, NULL);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
 }
 
 static const struct of_device_id bcm2835_pm_of_match[] = {
 	{ .compatible = "brcm,bcm2835-pm-wdt", },
+	{ .compatible = "brcm,bcm2835-pm", },
 	{},
 };
 MODULE_DEVICE_TABLE(of, bcm2835_pm_of_match);
diff --git a/drivers/soc/bcm/Kconfig b/drivers/soc/bcm/Kconfig
index 055a845ed979..fe1af29560e9 100644
--- a/drivers/soc/bcm/Kconfig
+++ b/drivers/soc/bcm/Kconfig
@@ -1,5 +1,16 @@
 menu "Broadcom SoC drivers"
 
+config BCM2835_POWER
+	bool "BCM2835 power domain driver"
+	depends on ARCH_BCM2835 || (COMPILE_TEST && OF)
+	select PM_GENERIC_DOMAINS if PM
+	select RESET_CONTROLLER
+	help
+	  This enables support for the BCM2835 power domains and reset
+	  controller.  Any usage of power domains by the Raspberry Pi
+	  firmware means that Linux usage of the same power domain
+	  must be accessed using the RASPBERRYPI_POWER driver
+
 config RASPBERRYPI_POWER
 	bool "Raspberry Pi power domain driver"
 	depends on ARCH_BCM2835 || (COMPILE_TEST && OF)
diff --git a/drivers/soc/bcm/Makefile b/drivers/soc/bcm/Makefile
index dc4fced72d21..c81df4b2403c 100644
--- a/drivers/soc/bcm/Makefile
+++ b/drivers/soc/bcm/Makefile
@@ -1,2 +1,3 @@
+obj-$(CONFIG_BCM2835_POWER)	+= bcm2835-power.o
 obj-$(CONFIG_RASPBERRYPI_POWER)	+= raspberrypi-power.o
 obj-$(CONFIG_SOC_BRCMSTB)	+= brcmstb/
diff --git a/drivers/soc/bcm/bcm2835-power.c b/drivers/soc/bcm/bcm2835-power.c
new file mode 100644
index 000000000000..48412957ec7a
--- /dev/null
+++ b/drivers/soc/bcm/bcm2835-power.c
@@ -0,0 +1,661 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Power domain driver for Broadcom BCM2835
+ *
+ * Copyright (C) 2018 Broadcom
+ */
+
+#include <dt-bindings/soc/bcm2835-pm.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/mfd/bcm2835-pm.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/reset-controller.h>
+#include <linux/types.h>
+
+#define PM_GNRIC                        0x00
+#define PM_AUDIO                        0x04
+#define PM_STATUS                       0x18
+#define PM_RSTC				0x1c
+#define PM_RSTS				0x20
+#define PM_WDOG				0x24
+#define PM_PADS0			0x28
+#define PM_PADS2			0x2c
+#define PM_PADS3			0x30
+#define PM_PADS4			0x34
+#define PM_PADS5			0x38
+#define PM_PADS6			0x3c
+#define PM_CAM0				0x44
+#define PM_CAM0_LDOHPEN			BIT(2)
+#define PM_CAM0_LDOLPEN			BIT(1)
+#define PM_CAM0_CTRLEN			BIT(0)
+
+#define PM_CAM1				0x48
+#define PM_CAM1_LDOHPEN			BIT(2)
+#define PM_CAM1_LDOLPEN			BIT(1)
+#define PM_CAM1_CTRLEN			BIT(0)
+
+#define PM_CCP2TX			0x4c
+#define PM_CCP2TX_LDOEN			BIT(1)
+#define PM_CCP2TX_CTRLEN		BIT(0)
+
+#define PM_DSI0				0x50
+#define PM_DSI0_LDOHPEN			BIT(2)
+#define PM_DSI0_LDOLPEN			BIT(1)
+#define PM_DSI0_CTRLEN			BIT(0)
+
+#define PM_DSI1				0x54
+#define PM_DSI1_LDOHPEN			BIT(2)
+#define PM_DSI1_LDOLPEN			BIT(1)
+#define PM_DSI1_CTRLEN			BIT(0)
+
+#define PM_HDMI				0x58
+#define PM_HDMI_RSTDR			BIT(19)
+#define PM_HDMI_LDOPD			BIT(1)
+#define PM_HDMI_CTRLEN			BIT(0)
+
+#define PM_USB				0x5c
+/* The power gates must be enabled with this bit before enabling the LDO in the
+ * USB block.
+ */
+#define PM_USB_CTRLEN			BIT(0)
+
+#define PM_PXLDO			0x60
+#define PM_PXBG				0x64
+#define PM_DFT				0x68
+#define PM_SMPS				0x6c
+#define PM_XOSC				0x70
+#define PM_SPAREW			0x74
+#define PM_SPARER			0x78
+#define PM_AVS_RSTDR			0x7c
+#define PM_AVS_STAT			0x80
+#define PM_AVS_EVENT			0x84
+#define PM_AVS_INTEN			0x88
+#define PM_DUMMY			0xfc
+
+#define PM_IMAGE			0x108
+#define PM_GRAFX			0x10c
+#define PM_PROC				0x110
+#define PM_ENAB				BIT(12)
+#define PM_ISPRSTN			BIT(8)
+#define PM_H264RSTN			BIT(7)
+#define PM_PERIRSTN			BIT(6)
+#define PM_V3DRSTN			BIT(6)
+#define PM_ISFUNC			BIT(5)
+#define PM_MRDONE			BIT(4)
+#define PM_MEMREP			BIT(3)
+#define PM_ISPOW			BIT(2)
+#define PM_POWOK			BIT(1)
+#define PM_POWUP			BIT(0)
+#define PM_INRUSH_SHIFT			13
+#define PM_INRUSH_3_5_MA		0
+#define PM_INRUSH_5_MA			1
+#define PM_INRUSH_10_MA			2
+#define PM_INRUSH_20_MA			3
+#define PM_INRUSH_MASK			(3 << PM_INRUSH_SHIFT)
+
+#define PM_PASSWORD			0x5a000000
+
+#define PM_WDOG_TIME_SET		0x000fffff
+#define PM_RSTC_WRCFG_CLR		0xffffffcf
+#define PM_RSTS_HADWRH_SET		0x00000040
+#define PM_RSTC_WRCFG_SET		0x00000030
+#define PM_RSTC_WRCFG_FULL_RESET	0x00000020
+#define PM_RSTC_RESET			0x00000102
+
+#define PM_READ(reg) readl(power->base + (reg))
+#define PM_WRITE(reg, val) writel(PM_PASSWORD | (val), power->base + (reg))
+
+#define ASB_BRDG_VERSION                0x00
+#define ASB_CPR_CTRL                    0x04
+
+#define ASB_V3D_S_CTRL			0x08
+#define ASB_V3D_M_CTRL			0x0c
+#define ASB_ISP_S_CTRL			0x10
+#define ASB_ISP_M_CTRL			0x14
+#define ASB_H264_S_CTRL			0x18
+#define ASB_H264_M_CTRL			0x1c
+
+#define ASB_REQ_STOP                    BIT(0)
+#define ASB_ACK                         BIT(1)
+#define ASB_EMPTY                       BIT(2)
+#define ASB_FULL                        BIT(3)
+
+#define ASB_AXI_BRDG_ID			0x20
+
+#define ASB_READ(reg) readl(power->asb + (reg))
+#define ASB_WRITE(reg, val) writel(PM_PASSWORD | (val), power->asb + (reg))
+
+struct bcm2835_power_domain {
+	struct generic_pm_domain base;
+	struct bcm2835_power *power;
+	u32 domain;
+	struct clk *clk;
+};
+
+struct bcm2835_power {
+	struct device		*dev;
+	/* PM registers. */
+	void __iomem		*base;
+	/* AXI Async bridge registers. */
+	void __iomem		*asb;
+
+	struct genpd_onecell_data pd_xlate;
+	struct bcm2835_power_domain domains[BCM2835_POWER_DOMAIN_COUNT];
+	struct reset_controller_dev reset;
+};
+
+static int bcm2835_asb_enable(struct bcm2835_power *power, u32 reg)
+{
+	u64 start = ktime_get_ns();
+
+	/* Enable the module's async AXI bridges. */
+	ASB_WRITE(reg, ASB_READ(reg) & ~ASB_REQ_STOP);
+	while (ASB_READ(reg) & ASB_ACK) {
+		cpu_relax();
+		if (ktime_get_ns() - start >= 1000)
+			return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static int bcm2835_asb_disable(struct bcm2835_power *power, u32 reg)
+{
+	u64 start = ktime_get_ns();
+
+	/* Enable the module's async AXI bridges. */
+	ASB_WRITE(reg, ASB_READ(reg) | ASB_REQ_STOP);
+	while (!(ASB_READ(reg) & ASB_ACK)) {
+		cpu_relax();
+		if (ktime_get_ns() - start >= 1000)
+			return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static int bcm2835_power_power_off(struct bcm2835_power_domain *pd, u32 pm_reg)
+{
+	struct bcm2835_power *power = pd->power;
+
+	/* Enable functional isolation */
+	PM_WRITE(pm_reg, PM_READ(pm_reg) & ~PM_ISFUNC);
+
+	/* Enable electrical isolation */
+	PM_WRITE(pm_reg, PM_READ(pm_reg) & ~PM_ISPOW);
+
+	/* Open the power switches. */
+	PM_WRITE(pm_reg, PM_READ(pm_reg) & ~PM_POWUP);
+
+	return 0;
+}
+
+static int bcm2835_power_power_on(struct bcm2835_power_domain *pd, u32 pm_reg)
+{
+	struct bcm2835_power *power = pd->power;
+	struct device *dev = power->dev;
+	u64 start;
+	int ret;
+	int inrush;
+	bool powok;
+
+	/* If it was already powered on by the fw, leave it that way. */
+	if (PM_READ(pm_reg) & PM_POWUP)
+		return 0;
+
+	/* Enable power.  Allowing too much current at once may result
+	 * in POWOK never getting set, so start low and ramp it up as
+	 * necessary to succeed.
+	 */
+	powok = false;
+	for (inrush = PM_INRUSH_3_5_MA; inrush <= PM_INRUSH_20_MA; inrush++) {
+		PM_WRITE(pm_reg,
+			 (PM_READ(pm_reg) & ~PM_INRUSH_MASK) |
+			 (inrush << PM_INRUSH_SHIFT) |
+			 PM_POWUP);
+
+		start = ktime_get_ns();
+		while (!(powok = !!(PM_READ(pm_reg) & PM_POWOK))) {
+			cpu_relax();
+			if (ktime_get_ns() - start >= 3000)
+				break;
+		}
+	}
+	if (!powok) {
+		dev_err(dev, "Timeout waiting for %s power OK\n",
+			pd->base.name);
+		ret = -ETIMEDOUT;
+		goto err_disable_powup;
+	}
+
+	/* Disable electrical isolation */
+	PM_WRITE(pm_reg, PM_READ(pm_reg) | PM_ISPOW);
+
+	/* Repair memory */
+	PM_WRITE(pm_reg, PM_READ(pm_reg) | PM_MEMREP);
+	start = ktime_get_ns();
+	while (!(PM_READ(pm_reg) & PM_MRDONE)) {
+		cpu_relax();
+		if (ktime_get_ns() - start >= 1000) {
+			dev_err(dev, "Timeout waiting for %s memory repair\n",
+				pd->base.name);
+			ret = -ETIMEDOUT;
+			goto err_disable_ispow;
+		}
+	}
+
+	/* Disable functional isolation */
+	PM_WRITE(pm_reg, PM_READ(pm_reg) | PM_ISFUNC);
+
+	return 0;
+
+err_disable_ispow:
+	PM_WRITE(pm_reg, PM_READ(pm_reg) & ~PM_ISPOW);
+err_disable_powup:
+	PM_WRITE(pm_reg, PM_READ(pm_reg) & ~(PM_POWUP | PM_INRUSH_MASK));
+	return ret;
+}
+
+static int bcm2835_asb_power_on(struct bcm2835_power_domain *pd,
+				u32 pm_reg,
+				u32 asb_m_reg,
+				u32 asb_s_reg,
+				u32 reset_flags)
+{
+	struct bcm2835_power *power = pd->power;
+	int ret;
+
+	ret = clk_prepare_enable(pd->clk);
+	if (ret) {
+		dev_err(power->dev, "Failed to enable clock for %s\n",
+			pd->base.name);
+		return ret;
+	}
+
+	/* Wait 32 clocks for reset to propagate, 1 us will be enough */
+	udelay(1);
+
+	clk_disable_unprepare(pd->clk);
+
+	/* Deassert the resets. */
+	PM_WRITE(pm_reg, PM_READ(pm_reg) | reset_flags);
+
+	ret = clk_prepare_enable(pd->clk);
+	if (ret) {
+		dev_err(power->dev, "Failed to enable clock for %s\n",
+			pd->base.name);
+		goto err_enable_resets;
+	}
+
+	ret = bcm2835_asb_enable(power, asb_m_reg);
+	if (ret) {
+		dev_err(power->dev, "Failed to enable ASB master for %s\n",
+			pd->base.name);
+		goto err_disable_clk;
+	}
+	ret = bcm2835_asb_enable(power, asb_s_reg);
+	if (ret) {
+		dev_err(power->dev, "Failed to enable ASB slave for %s\n",
+			pd->base.name);
+		goto err_disable_asb_master;
+	}
+
+	return 0;
+
+err_disable_asb_master:
+	bcm2835_asb_disable(power, asb_m_reg);
+err_disable_clk:
+	clk_disable_unprepare(pd->clk);
+err_enable_resets:
+	PM_WRITE(pm_reg, PM_READ(pm_reg) & ~reset_flags);
+	return ret;
+}
+
+static int bcm2835_asb_power_off(struct bcm2835_power_domain *pd,
+				 u32 pm_reg,
+				 u32 asb_m_reg,
+				 u32 asb_s_reg,
+				 u32 reset_flags)
+{
+	struct bcm2835_power *power = pd->power;
+	int ret;
+
+	ret = bcm2835_asb_disable(power, asb_s_reg);
+	if (ret) {
+		dev_warn(power->dev, "Failed to disable ASB slave for %s\n",
+			 pd->base.name);
+		return ret;
+	}
+	ret = bcm2835_asb_disable(power, asb_m_reg);
+	if (ret) {
+		dev_warn(power->dev, "Failed to disable ASB master for %s\n",
+			 pd->base.name);
+		bcm2835_asb_enable(power, asb_s_reg);
+		return ret;
+	}
+
+	clk_disable_unprepare(pd->clk);
+
+	/* Assert the resets. */
+	PM_WRITE(pm_reg, PM_READ(pm_reg) & ~reset_flags);
+
+	return 0;
+}
+
+static int bcm2835_power_pd_power_on(struct generic_pm_domain *domain)
+{
+	struct bcm2835_power_domain *pd =
+		container_of(domain, struct bcm2835_power_domain, base);
+	struct bcm2835_power *power = pd->power;
+
+	switch (pd->domain) {
+	case BCM2835_POWER_DOMAIN_GRAFX:
+		return bcm2835_power_power_on(pd, PM_GRAFX);
+
+	case BCM2835_POWER_DOMAIN_GRAFX_V3D:
+		return bcm2835_asb_power_on(pd, PM_GRAFX,
+					    ASB_V3D_M_CTRL, ASB_V3D_S_CTRL,
+					    PM_V3DRSTN);
+
+	case BCM2835_POWER_DOMAIN_IMAGE:
+		return bcm2835_power_power_on(pd, PM_IMAGE);
+
+	case BCM2835_POWER_DOMAIN_IMAGE_PERI:
+		return bcm2835_asb_power_on(pd, PM_IMAGE,
+					    0, 0,
+					    PM_PERIRSTN);
+
+	case BCM2835_POWER_DOMAIN_IMAGE_ISP:
+		return bcm2835_asb_power_on(pd, PM_IMAGE,
+					    ASB_ISP_M_CTRL, ASB_ISP_S_CTRL,
+					    PM_ISPRSTN);
+
+	case BCM2835_POWER_DOMAIN_IMAGE_H264:
+		return bcm2835_asb_power_on(pd, PM_IMAGE,
+					    ASB_H264_M_CTRL, ASB_H264_S_CTRL,
+					    PM_H264RSTN);
+
+	case BCM2835_POWER_DOMAIN_USB:
+		PM_WRITE(PM_USB, PM_USB_CTRLEN);
+		return 0;
+
+	case BCM2835_POWER_DOMAIN_DSI0:
+		PM_WRITE(PM_DSI0, PM_DSI0_CTRLEN);
+		PM_WRITE(PM_DSI0, PM_DSI0_CTRLEN | PM_DSI0_LDOHPEN);
+		return 0;
+
+	case BCM2835_POWER_DOMAIN_DSI1:
+		PM_WRITE(PM_DSI1, PM_DSI1_CTRLEN);
+		PM_WRITE(PM_DSI1, PM_DSI1_CTRLEN | PM_DSI1_LDOHPEN);
+		return 0;
+
+	case BCM2835_POWER_DOMAIN_CCP2TX:
+		PM_WRITE(PM_CCP2TX, PM_CCP2TX_CTRLEN);
+		PM_WRITE(PM_CCP2TX, PM_CCP2TX_CTRLEN | PM_CCP2TX_LDOEN);
+		return 0;
+
+	case BCM2835_POWER_DOMAIN_HDMI:
+		PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) | PM_HDMI_RSTDR);
+		PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) | PM_HDMI_CTRLEN);
+		PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) & ~PM_HDMI_LDOPD);
+		usleep_range(100, 200);
+		PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) & ~PM_HDMI_RSTDR);
+		return 0;
+
+	default:
+		dev_err(power->dev, "Invalid domain %d\n", pd->domain);
+		return -EINVAL;
+	}
+}
+
+static int bcm2835_power_pd_power_off(struct generic_pm_domain *domain)
+{
+	struct bcm2835_power_domain *pd =
+		container_of(domain, struct bcm2835_power_domain, base);
+	struct bcm2835_power *power = pd->power;
+
+	switch (pd->domain) {
+	case BCM2835_POWER_DOMAIN_GRAFX:
+		return bcm2835_power_power_off(pd, PM_GRAFX);
+
+	case BCM2835_POWER_DOMAIN_GRAFX_V3D:
+		return bcm2835_asb_power_off(pd, PM_GRAFX,
+					     ASB_V3D_M_CTRL, ASB_V3D_S_CTRL,
+					     PM_V3DRSTN);
+
+	case BCM2835_POWER_DOMAIN_IMAGE:
+		return bcm2835_power_power_off(pd, PM_IMAGE);
+
+	case BCM2835_POWER_DOMAIN_IMAGE_PERI:
+		return bcm2835_asb_power_off(pd, PM_IMAGE,
+					     0, 0,
+					     PM_PERIRSTN);
+
+	case BCM2835_POWER_DOMAIN_IMAGE_ISP:
+		return bcm2835_asb_power_off(pd, PM_IMAGE,
+					     ASB_ISP_M_CTRL, ASB_ISP_S_CTRL,
+					     PM_ISPRSTN);
+
+	case BCM2835_POWER_DOMAIN_IMAGE_H264:
+		return bcm2835_asb_power_off(pd, PM_IMAGE,
+					     ASB_H264_M_CTRL, ASB_H264_S_CTRL,
+					     PM_H264RSTN);
+
+	case BCM2835_POWER_DOMAIN_USB:
+		PM_WRITE(PM_USB, 0);
+		return 0;
+
+	case BCM2835_POWER_DOMAIN_DSI0:
+		PM_WRITE(PM_DSI0, PM_DSI0_CTRLEN);
+		PM_WRITE(PM_DSI0, 0);
+		return 0;
+
+	case BCM2835_POWER_DOMAIN_DSI1:
+		PM_WRITE(PM_DSI1, PM_DSI1_CTRLEN);
+		PM_WRITE(PM_DSI1, 0);
+		return 0;
+
+	case BCM2835_POWER_DOMAIN_CCP2TX:
+		PM_WRITE(PM_CCP2TX, PM_CCP2TX_CTRLEN);
+		PM_WRITE(PM_CCP2TX, 0);
+		return 0;
+
+	case BCM2835_POWER_DOMAIN_HDMI:
+		PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) | PM_HDMI_LDOPD);
+		PM_WRITE(PM_HDMI, PM_READ(PM_HDMI) & ~PM_HDMI_CTRLEN);
+		return 0;
+
+	default:
+		dev_err(power->dev, "Invalid domain %d\n", pd->domain);
+		return -EINVAL;
+	}
+}
+
+static void
+bcm2835_init_power_domain(struct bcm2835_power *power,
+			  int pd_xlate_index, const char *name)
+{
+	struct device *dev = power->dev;
+	struct bcm2835_power_domain *dom = &power->domains[pd_xlate_index];
+
+	dom->clk = devm_clk_get(dev->parent, name);
+
+	dom->base.name = name;
+	dom->base.power_on = bcm2835_power_pd_power_on;
+	dom->base.power_off = bcm2835_power_pd_power_off;
+
+	dom->domain = pd_xlate_index;
+	dom->power = power;
+
+	/* XXX: on/off at boot? */
+	pm_genpd_init(&dom->base, NULL, true);
+
+	power->pd_xlate.domains[pd_xlate_index] = &dom->base;
+}
+
+/** bcm2835_reset_reset - Resets a block that has a reset line in the
+ * PM block.
+ *
+ * The consumer of the reset controller must have the power domain up
+ * -- there's no reset ability with the power domain down.  To reset
+ * the sub-block, we just disable its access to memory through the
+ * ASB, reset, and re-enable.
+ */
+static int bcm2835_reset_reset(struct reset_controller_dev *rcdev,
+			       unsigned long id)
+{
+	struct bcm2835_power *power = container_of(rcdev, struct bcm2835_power,
+						   reset);
+	struct bcm2835_power_domain *pd;
+	int ret;
+
+	switch (id) {
+	case BCM2835_RESET_V3D:
+		pd = &power->domains[BCM2835_POWER_DOMAIN_GRAFX_V3D];
+		break;
+	case BCM2835_RESET_H264:
+		pd = &power->domains[BCM2835_POWER_DOMAIN_IMAGE_H264];
+		break;
+	case BCM2835_RESET_ISP:
+		pd = &power->domains[BCM2835_POWER_DOMAIN_IMAGE_ISP];
+		break;
+	default:
+		dev_err(power->dev, "Bad reset id %ld\n", id);
+		return -EINVAL;
+	}
+
+	ret = bcm2835_power_pd_power_off(&pd->base);
+	if (ret)
+		return ret;
+
+	return bcm2835_power_pd_power_on(&pd->base);
+}
+
+static int bcm2835_reset_status(struct reset_controller_dev *rcdev,
+				unsigned long id)
+{
+	struct bcm2835_power *power = container_of(rcdev, struct bcm2835_power,
+						   reset);
+
+	switch (id) {
+	case BCM2835_RESET_V3D:
+		return !PM_READ(PM_GRAFX & PM_V3DRSTN);
+	case BCM2835_RESET_H264:
+		return !PM_READ(PM_IMAGE & PM_H264RSTN);
+	case BCM2835_RESET_ISP:
+		return !PM_READ(PM_IMAGE & PM_ISPRSTN);
+	default:
+		return -EINVAL;
+	}
+}
+
+const struct reset_control_ops bcm2835_reset_ops = {
+	.reset = bcm2835_reset_reset,
+	.status = bcm2835_reset_status,
+};
+
+static const char *const power_domain_names[] = {
+	[BCM2835_POWER_DOMAIN_GRAFX] = "grafx",
+	[BCM2835_POWER_DOMAIN_GRAFX_V3D] = "v3d",
+
+	[BCM2835_POWER_DOMAIN_IMAGE] = "image",
+	[BCM2835_POWER_DOMAIN_IMAGE_PERI] = "peri_image",
+	[BCM2835_POWER_DOMAIN_IMAGE_H264] = "h264",
+	[BCM2835_POWER_DOMAIN_IMAGE_ISP] = "isp",
+
+	[BCM2835_POWER_DOMAIN_USB] = "usb",
+	[BCM2835_POWER_DOMAIN_DSI0] = "dsi0",
+	[BCM2835_POWER_DOMAIN_DSI1] = "dsi1",
+	[BCM2835_POWER_DOMAIN_CAM0] = "cam0",
+	[BCM2835_POWER_DOMAIN_CAM1] = "cam1",
+	[BCM2835_POWER_DOMAIN_CCP2TX] = "ccp2tx",
+	[BCM2835_POWER_DOMAIN_HDMI] = "hdmi",
+};
+
+static int bcm2835_power_probe(struct platform_device *pdev)
+{
+	struct bcm2835_pm *pm = dev_get_drvdata(pdev->dev.parent);
+	struct device *dev = &pdev->dev;
+	struct bcm2835_power *power;
+	static const struct {
+		int parent, child;
+	} domain_deps[] = {
+		{ BCM2835_POWER_DOMAIN_GRAFX, BCM2835_POWER_DOMAIN_GRAFX_V3D },
+		{ BCM2835_POWER_DOMAIN_IMAGE, BCM2835_POWER_DOMAIN_IMAGE_PERI },
+		{ BCM2835_POWER_DOMAIN_IMAGE, BCM2835_POWER_DOMAIN_IMAGE_H264 },
+		{ BCM2835_POWER_DOMAIN_IMAGE, BCM2835_POWER_DOMAIN_IMAGE_ISP },
+		{ BCM2835_POWER_DOMAIN_IMAGE_PERI, BCM2835_POWER_DOMAIN_USB },
+		{ BCM2835_POWER_DOMAIN_IMAGE_PERI, BCM2835_POWER_DOMAIN_CAM0 },
+		{ BCM2835_POWER_DOMAIN_IMAGE_PERI, BCM2835_POWER_DOMAIN_CAM1 },
+	};
+	int ret, i;
+	u32 id;
+
+	power = devm_kzalloc(dev, sizeof(*power), GFP_KERNEL);
+	if (!power)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, power);
+
+	power->dev = dev;
+	power->base = pm->base;
+	power->asb = pm->asb;
+
+	id = ASB_READ(ASB_AXI_BRDG_ID);
+	if (id != 0x62726467 /* "BRDG" */) {
+		dev_err(dev, "ASB register ID returned 0x%08x\n", id);
+		return -ENODEV;
+	}
+
+	power->pd_xlate.domains = devm_kcalloc(dev,
+					       ARRAY_SIZE(power_domain_names),
+					       sizeof(*power->pd_xlate.domains),
+					       GFP_KERNEL);
+	if (!power->pd_xlate.domains)
+		return -ENOMEM;
+
+	power->pd_xlate.num_domains = ARRAY_SIZE(power_domain_names);
+
+	for (i = 0; i < ARRAY_SIZE(power_domain_names); i++)
+		bcm2835_init_power_domain(power, i, power_domain_names[i]);
+
+	for (i = 0; i < ARRAY_SIZE(domain_deps); i++) {
+		pm_genpd_add_subdomain(&power->domains[domain_deps[i].parent].base,
+				       &power->domains[domain_deps[i].child].base);
+	}
+
+	power->reset.owner = THIS_MODULE;
+	power->reset.nr_resets = BCM2835_RESET_COUNT;
+	power->reset.ops = &bcm2835_reset_ops;
+	power->reset.of_node = dev->parent->of_node;
+
+	ret = devm_reset_controller_register(dev, &power->reset);
+	if (ret)
+		return ret;
+
+	of_genpd_add_provider_onecell(dev->parent->of_node, &power->pd_xlate);
+
+	dev_info(dev, "Broadcom BCM2835 power domains driver");
+	return 0;
+}
+
+static int bcm2835_power_remove(struct platform_device *pdev)
+{
+	return 0;
+}
+
+static struct platform_driver bcm2835_power_driver = {
+	.probe		= bcm2835_power_probe,
+	.remove		= bcm2835_power_remove,
+	.driver = {
+		.name =	"bcm2835-power",
+	},
+};
+module_platform_driver(bcm2835_power_driver);
+
+MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
+MODULE_DESCRIPTION("Driver for Broadcom BCM2835 PM power domains and reset");
+MODULE_LICENSE("GPL");
diff --git a/include/dt-bindings/soc/bcm2835-pm.h b/include/dt-bindings/soc/bcm2835-pm.h
new file mode 100644
index 000000000000..153d75b8d99f
--- /dev/null
+++ b/include/dt-bindings/soc/bcm2835-pm.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: (GPL-2.0+ OR MIT) */
+
+#ifndef _DT_BINDINGS_ARM_BCM2835_PM_H
+#define _DT_BINDINGS_ARM_BCM2835_PM_H
+
+#define BCM2835_POWER_DOMAIN_GRAFX		0
+#define BCM2835_POWER_DOMAIN_GRAFX_V3D		1
+#define BCM2835_POWER_DOMAIN_IMAGE		2
+#define BCM2835_POWER_DOMAIN_IMAGE_PERI		3
+#define BCM2835_POWER_DOMAIN_IMAGE_ISP		4
+#define BCM2835_POWER_DOMAIN_IMAGE_H264		5
+#define BCM2835_POWER_DOMAIN_USB		6
+#define BCM2835_POWER_DOMAIN_DSI0		7
+#define BCM2835_POWER_DOMAIN_DSI1		8
+#define BCM2835_POWER_DOMAIN_CAM0		9
+#define BCM2835_POWER_DOMAIN_CAM1		10
+#define BCM2835_POWER_DOMAIN_CCP2TX		11
+#define BCM2835_POWER_DOMAIN_HDMI		12
+
+#define BCM2835_POWER_DOMAIN_COUNT		13
+
+#define BCM2835_RESET_V3D			0
+#define BCM2835_RESET_ISP			1
+#define BCM2835_RESET_H264			2
+
+#define BCM2835_RESET_COUNT			3
+
+#endif /* _DT_BINDINGS_ARM_BCM2835_PM_H */
diff --git a/include/linux/mfd/bcm2835-pm.h b/include/linux/mfd/bcm2835-pm.h
index b7d0ee1feffa..ed37dc40e82a 100644
--- a/include/linux/mfd/bcm2835-pm.h
+++ b/include/linux/mfd/bcm2835-pm.h
@@ -8,6 +8,7 @@
 struct bcm2835_pm {
 	struct device *dev;
 	void __iomem *base;
+	void __iomem *asb;
 };
 
 #endif /* BCM2835_MFD_PM_H */
-- 
2.20.0.rc1

[PATCH v3 4/5] ARM: bcm283x: Extend the WDT DT node out to cover the whole PM block.

[Eric Anholt]

It was covering part of the PM block's range, up to the WDT regs.  To
support the rest of the PM block's functionality, we need the full
register range plus the AXI Async Bridge regs for PM sequencing.

This doesn't convert any of the consumers over to the new binding yet,
since we will need to be careful in coordinating our usage of firmware
services that might power domains on and off versus the bcm2835-pm
driver's access of those same domains.

Signed-off-by: Eric Anholt <eric@anholt.net>
---
 arch/arm/boot/dts/bcm283x.dtsi | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/arch/arm/boot/dts/bcm283x.dtsi b/arch/arm/boot/dts/bcm283x.dtsi
index 31b29646b14c..bd5be68b4561 100644
--- a/arch/arm/boot/dts/bcm283x.dtsi
+++ b/arch/arm/boot/dts/bcm283x.dtsi
@@ -121,8 +121,16 @@
 		};
 
 		watchdog@7e100000 {
-			compatible = "brcm,bcm2835-pm-wdt";
-			reg = <0x7e100000 0x28>;
+			compatible = "brcm,bcm2835-pm", "brcm,bcm2835-pm-wdt";
+			#power-domain-cells = <1>;
+			#reset-cells = <1>;
+			reg = <0x7e100000 0x114>,
+			      <0x7e00a000 0x24>;
+			clocks = <&clocks BCM2835_CLOCK_V3D>,
+				 <&clocks BCM2835_CLOCK_PERI_IMAGE>,
+				 <&clocks BCM2835_CLOCK_H264>,
+				 <&clocks BCM2835_CLOCK_ISP>;
+			clock-names = "v3d", "peri_image", "h264", "isp";
 		};
 
 		clocks: cprman@7e101000 {
-- 
2.20.0.rc1

[PATCH v3 5/5] ARM: bcm283x: Switch V3D over to using the PM driver instead of firmware.

[Eric Anholt]

The GRAFX domain only contains V3D, and this driver should be the only
accessor of V3D (firmware usage gets disabled when V3D is in the DT),
so we can safely make Linux control the GRAFX and GRAFX_V3D power
domains.

Signed-off-by: Eric Anholt <eric@anholt.net>
---
 arch/arm/boot/dts/bcm2835-rpi.dtsi | 4 ----
 arch/arm/boot/dts/bcm283x.dtsi     | 4 +++-
 2 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/arch/arm/boot/dts/bcm2835-rpi.dtsi b/arch/arm/boot/dts/bcm2835-rpi.dtsi
index cb2d6d78a7fb..21a930148709 100644
--- a/arch/arm/boot/dts/bcm2835-rpi.dtsi
+++ b/arch/arm/boot/dts/bcm2835-rpi.dtsi
@@ -87,10 +87,6 @@
 	power-domains = <&power RPI_POWER_DOMAIN_USB>;
 };
 
-&v3d {
-	power-domains = <&power RPI_POWER_DOMAIN_V3D>;
-};
-
 &hdmi {
 	power-domains = <&power RPI_POWER_DOMAIN_HDMI>;
 	status = "okay";
diff --git a/arch/arm/boot/dts/bcm283x.dtsi b/arch/arm/boot/dts/bcm283x.dtsi
index bd5be68b4561..ce7bc9cc43ae 100644
--- a/arch/arm/boot/dts/bcm283x.dtsi
+++ b/arch/arm/boot/dts/bcm283x.dtsi
@@ -3,6 +3,7 @@
 #include <dt-bindings/clock/bcm2835-aux.h>
 #include <dt-bindings/gpio/gpio.h>
 #include <dt-bindings/interrupt-controller/irq.h>
+#include <dt-bindings/soc/bcm2835-pm.h>
 
 /* firmware-provided startup stubs live here, where the secondary CPUs are
  * spinning.
@@ -120,7 +121,7 @@
 			#interrupt-cells = <2>;
 		};
 
-		watchdog@7e100000 {
+		pm: watchdog@7e100000 {
 			compatible = "brcm,bcm2835-pm", "brcm,bcm2835-pm-wdt";
 			#power-domain-cells = <1>;
 			#reset-cells = <1>;
@@ -637,6 +638,7 @@
 			compatible = "brcm,bcm2835-v3d";
 			reg = <0x7ec00000 0x1000>;
 			interrupts = <1 10>;
+			power-domains = <&pm BCM2835_POWER_DOMAIN_GRAFX_V3D>;
 		};
 
 		vc4: gpu {
-- 
2.20.0.rc1

Re: [PATCH v3 2/5] bcm2835-pm: Move bcm2835-watchdog's DT probe to an MFD.

[Guenter Roeck]

On Fri, Nov 30, 2018 at 12:27:40PM -0800, Eric Anholt wrote:
> The PM block that the wdt driver was binding to actually has multiple
> features we want to expose (power domains, reset, watchdog).  Move the
> DT attachment to a MFD driver and make WDT probe against MFD.
> 
> Signed-off-by: Eric Anholt <eric@anholt.net>

For watchdog:

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
> 
> v3: don't reset bcm2835_power_off_wdt on remove, drop pm driver's
>     empty remove, sort includes, add a "static".
> 
>  arch/arm/mach-bcm/Kconfig      |  1 +
>  drivers/mfd/Makefile           |  1 +
>  drivers/mfd/bcm2835-pm.c       | 64 ++++++++++++++++++++++++++++++++++
>  drivers/watchdog/bcm2835_wdt.c | 26 +++++---------
>  include/linux/mfd/bcm2835-pm.h | 13 +++++++
>  5 files changed, 88 insertions(+), 17 deletions(-)
>  create mode 100644 drivers/mfd/bcm2835-pm.c
>  create mode 100644 include/linux/mfd/bcm2835-pm.h
> 
> diff --git a/arch/arm/mach-bcm/Kconfig b/arch/arm/mach-bcm/Kconfig
> index 25aac6ee2ab1..95242c2162a2 100644
> --- a/arch/arm/mach-bcm/Kconfig
> +++ b/arch/arm/mach-bcm/Kconfig
> @@ -167,6 +167,7 @@ config ARCH_BCM2835
>  	select BCM2835_TIMER
>  	select PINCTRL
>  	select PINCTRL_BCM2835
> +	select MFD_CORE
>  	help
>  	  This enables support for the Broadcom BCM2835 and BCM2836 SoCs.
>  	  This SoC is used in the Raspberry Pi and Roku 2 devices.
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index 12980a4ad460..ee6fb6af655e 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -10,6 +10,7 @@ obj-$(CONFIG_MFD_88PM805)	+= 88pm805.o 88pm80x.o
>  obj-$(CONFIG_MFD_ACT8945A)	+= act8945a.o
>  obj-$(CONFIG_MFD_SM501)		+= sm501.o
>  obj-$(CONFIG_MFD_ASIC3)		+= asic3.o tmio_core.o
> +obj-$(CONFIG_ARCH_BCM2835)	+= bcm2835-pm.o
>  obj-$(CONFIG_MFD_BCM590XX)	+= bcm590xx.o
>  obj-$(CONFIG_MFD_BD9571MWV)	+= bd9571mwv.o
>  cros_ec_core-objs		:= cros_ec.o
> diff --git a/drivers/mfd/bcm2835-pm.c b/drivers/mfd/bcm2835-pm.c
> new file mode 100644
> index 000000000000..53839e6a81e7
> --- /dev/null
> +++ b/drivers/mfd/bcm2835-pm.c
> @@ -0,0 +1,64 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * PM MFD driver for Broadcom BCM2835
> + *
> + * This driver binds to the PM block and creates the MFD device for
> + * the WDT driver.
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/io.h>
> +#include <linux/mfd/bcm2835-pm.h>
> +#include <linux/mfd/core.h>
> +#include <linux/module.h>
> +#include <linux/of_address.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/types.h>
> +#include <linux/watchdog.h>
> +
> +static const struct mfd_cell bcm2835_pm_devs[] = {
> +	{ .name = "bcm2835-wdt" },
> +};
> +
> +static int bcm2835_pm_probe(struct platform_device *pdev)
> +{
> +	struct resource *res;
> +	struct device *dev = &pdev->dev;
> +	struct bcm2835_pm *pm;
> +
> +	pm = devm_kzalloc(dev, sizeof(*pm), GFP_KERNEL);
> +	if (!pm)
> +		return -ENOMEM;
> +	platform_set_drvdata(pdev, pm);
> +
> +	pm->dev = dev;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	pm->base = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(pm->base))
> +		return PTR_ERR(pm->base);
> +
> +	return devm_mfd_add_devices(dev, -1,
> +				    bcm2835_pm_devs, ARRAY_SIZE(bcm2835_pm_devs),
> +				    NULL, 0, NULL);
> +}
> +
> +static const struct of_device_id bcm2835_pm_of_match[] = {
> +	{ .compatible = "brcm,bcm2835-pm-wdt", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, bcm2835_pm_of_match);
> +
> +static struct platform_driver bcm2835_pm_driver = {
> +	.probe		= bcm2835_pm_probe,
> +	.driver = {
> +		.name =	"bcm2835-pm",
> +		.of_match_table = bcm2835_pm_of_match,
> +	},
> +};
> +module_platform_driver(bcm2835_pm_driver);
> +
> +MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
> +MODULE_DESCRIPTION("Driver for Broadcom BCM2835 PM MFD");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/watchdog/bcm2835_wdt.c b/drivers/watchdog/bcm2835_wdt.c
> index ed05514cc2dc..1834524ae373 100644
> --- a/drivers/watchdog/bcm2835_wdt.c
> +++ b/drivers/watchdog/bcm2835_wdt.c
> @@ -12,6 +12,7 @@
>  
>  #include <linux/delay.h>
>  #include <linux/types.h>
> +#include <linux/mfd/bcm2835-pm.h>
>  #include <linux/module.h>
>  #include <linux/io.h>
>  #include <linux/watchdog.h>
> @@ -47,6 +48,8 @@ struct bcm2835_wdt {
>  	spinlock_t		lock;
>  };
>  
> +static struct bcm2835_wdt *bcm2835_power_off_wdt;
> +
>  static unsigned int heartbeat;
>  static bool nowayout = WATCHDOG_NOWAYOUT;
>  
> @@ -148,10 +151,7 @@ static struct watchdog_device bcm2835_wdt_wdd = {
>   */
>  static void bcm2835_power_off(void)
>  {
> -	struct device_node *np =
> -		of_find_compatible_node(NULL, NULL, "brcm,bcm2835-pm-wdt");
> -	struct platform_device *pdev = of_find_device_by_node(np);
> -	struct bcm2835_wdt *wdt = platform_get_drvdata(pdev);
> +	struct bcm2835_wdt *wdt = bcm2835_power_off_wdt;
>  	u32 val;
>  
>  	/*
> @@ -169,7 +169,7 @@ static void bcm2835_power_off(void)
>  
>  static int bcm2835_wdt_probe(struct platform_device *pdev)
>  {
> -	struct resource *res;
> +	struct bcm2835_pm *pm = dev_get_drvdata(pdev->dev.parent);
>  	struct device *dev = &pdev->dev;
>  	struct bcm2835_wdt *wdt;
>  	int err;
> @@ -181,10 +181,7 @@ static int bcm2835_wdt_probe(struct platform_device *pdev)
>  
>  	spin_lock_init(&wdt->lock);
>  
> -	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> -	wdt->base = devm_ioremap_resource(dev, res);
> -	if (IS_ERR(wdt->base))
> -		return PTR_ERR(wdt->base);
> +	wdt->base = pm->base;
>  
>  	watchdog_set_drvdata(&bcm2835_wdt_wdd, wdt);
>  	watchdog_init_timeout(&bcm2835_wdt_wdd, heartbeat, dev);
> @@ -211,8 +208,10 @@ static int bcm2835_wdt_probe(struct platform_device *pdev)
>  		return err;
>  	}
>  
> -	if (pm_power_off == NULL)
> +	if (pm_power_off == NULL) {
>  		pm_power_off = bcm2835_power_off;
> +		bcm2835_power_off_wdt = wdt;
> +	}
>  
>  	dev_info(dev, "Broadcom BCM2835 watchdog timer");
>  	return 0;
> @@ -226,18 +225,11 @@ static int bcm2835_wdt_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> -static const struct of_device_id bcm2835_wdt_of_match[] = {
> -	{ .compatible = "brcm,bcm2835-pm-wdt", },
> -	{},
> -};
> -MODULE_DEVICE_TABLE(of, bcm2835_wdt_of_match);
> -
>  static struct platform_driver bcm2835_wdt_driver = {
>  	.probe		= bcm2835_wdt_probe,
>  	.remove		= bcm2835_wdt_remove,
>  	.driver = {
>  		.name =		"bcm2835-wdt",
> -		.of_match_table = bcm2835_wdt_of_match,
>  	},
>  };
>  module_platform_driver(bcm2835_wdt_driver);
> diff --git a/include/linux/mfd/bcm2835-pm.h b/include/linux/mfd/bcm2835-pm.h
> new file mode 100644
> index 000000000000..b7d0ee1feffa
> --- /dev/null
> +++ b/include/linux/mfd/bcm2835-pm.h
> @@ -0,0 +1,13 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +
> +#ifndef BCM2835_MFD_PM_H
> +#define BCM2835_MFD_PM_H
> +
> +#include <linux/regmap.h>
> +
> +struct bcm2835_pm {
> +	struct device *dev;
> +	void __iomem *base;
> +};
> +
> +#endif /* BCM2835_MFD_PM_H */
> -- 
> 2.20.0.rc1
> 

Re: [PATCH v3 1/5] dt-bindings: soc: Add a new binding for the BCM2835 PM node.

[Rob Herring]

On Fri, 30 Nov 2018 12:27:39 -0800, Eric Anholt wrote:
> This binding supersedes the bcm2835-pm-wdt binding which only covered
> enough to provide a watchdog, but the HW block is actually mostly
> about power domains.
> 
> Signed-off-by: Eric Anholt <eric@anholt.net>
> ---
>  .../bindings/soc/bcm/brcm,bcm2835-pm.txt      | 42 +++++++++++++++++++
>  1 file changed, 42 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-pm.txt
> 

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH v3 3/5] soc: bcm: bcm2835-pm: Add support for power domains under a new binding.

[Rob Herring]

On Fri, Nov 30, 2018 at 12:27:41PM -0800, Eric Anholt wrote:
> This provides a free software alternative to raspberrypi-power.c's
> firmware calls to manage power domains.  It also exposes a reset line,
> where previously the vc4 driver had to try to force power off the
> domain in order to trigger a reset.
> 
> Signed-off-by: Eric Anholt <eric@anholt.net>
> ---
>  drivers/mfd/bcm2835-pm.c             |  36 +-
>  drivers/soc/bcm/Kconfig              |  11 +
>  drivers/soc/bcm/Makefile             |   1 +
>  drivers/soc/bcm/bcm2835-power.c      | 661 +++++++++++++++++++++++++++
>  include/dt-bindings/soc/bcm2835-pm.h |  28 ++

Acked-by: Rob Herring <robh@kernel.org>

>  include/linux/mfd/bcm2835-pm.h       |   1 +
>  6 files changed, 734 insertions(+), 4 deletions(-)
>  create mode 100644 drivers/soc/bcm/bcm2835-power.c
>  create mode 100644 include/dt-bindings/soc/bcm2835-pm.h

Re: [PATCH v3 1/5] dt-bindings: soc: Add a new binding for the BCM2835 PM node.

[Stefan Wahren]

Hi Eric,

[add Sebastian]

> Eric Anholt <eric@anholt.net> hat am 30. November 2018 um 21:27 geschrieben:
> 
> 
> This binding supersedes the bcm2835-pm-wdt binding which only covered
> enough to provide a watchdog, but the HW block is actually mostly
> about power domains.
> 
> Signed-off-by: Eric Anholt <eric@anholt.net>
> ---
>  .../bindings/soc/bcm/brcm,bcm2835-pm.txt      | 42 +++++++++++++++++++
>  1 file changed, 42 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-pm.txt
> 
> diff --git a/Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-pm.txt b/Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-pm.txt
> new file mode 100644
> index 000000000000..7818d33a158f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/soc/bcm/brcm,bcm2835-pm.txt
> @@ -0,0 +1,42 @@
> +BCM2835 PM (Power domains, watchdog)
> +
> +The PM block controls power domains and some reset lines, and includes
> +a watchdog timer.  This binding supersedes the brcm,bcm2835-pm-wdt
> +binding which covered some of PM's register range and functionality.
> +
> +Required properties:
> +
> +- compatible:		Should be "brcm,bcm2835-pm"
> +- reg:			Specifies base physical address and size of the two
> +			  register ranges ("PM" and "ASYNC_BRIDGE" in that
> +			  order)
> +- clocks:		a) v3d: The V3D clock from CPRMAN
> +			b) peri_image: The PERI_IMAGE clock from CPRMAN
> +			c) h264: The H264 clock from CPRMAN
> +			d) isp: The ISP clock from CPRMAN
> +- #reset-cells: 	Should be 1.  This property follows the reset controller
> +			  bindings[1].
> +- #power-domain-cells:	Should be 1.  This property follows the power domain
> +			  bindings[2].
> +
> +Optional properties:
> +
> +- timeout-sec:	Contains the watchdog timeout in seconds
> +
> +[1] Documentation/devicetree/bindings/reset/reset.txt
> +[2] Documentation/devicetree/bindings/power/power_domain.txt
> +

sorry for my late reply. I hope we can take the opportunity of a new binding to fix an old issue of the bcm2835-wdt driver. The watchdog driver sets the pm_power_off callback without checking for "system-power-controller" property [3]. As a result we can't use another poweroff controller like e.g. gpio-poweroff. In downstream this has been workarounded by an additional devicetree property for the gpio-poweroff driver [4]. But this isn't the right way because the issue is in the bcm2835 watchdog driver not in all the other reset controller.

Suggested pseudo code:

if (!pm_power_off) {
    /* Preserve the old behavior of watchdog driver in case of old DTB */
    if (!of_device_is_compatible(dev->of.node, "brcm,bcm2835-pm") ||
        of_device_is_system_power_controller(dev->of.node))
        pm_power_off = bcm2835_power_off;
}

Best regards
Stefan

[3] - https://elixir.bootlin.com/linux/latest/source/Documentation/devicetree/bindings/power/power-controller.txt
[4] - https://github.com/raspberrypi/linux/commit/f86dcfac0a4e478fee40b5a3729ff1b159ae91ee