[PATCH v6 0/5] i.MX6 PU power domain support

[PATCH v6 0/5] i.MX6 PU power domain support

[Philipp Zabel]

Hi,

in this version I fixed the issues Shawn pointed out last time.
Old blurb, fast-forward if you followed previous iterations:

The i.MX6Q can gate off the CPU and PU (GPU/VPU) power domains using the
Power Gating Controller (PGC) in the GPC register space. The CPU power
domain is already handled by wait state code, but the PU power domain can
be controlled using the generic power domain framework and power off the PU
supply regulator if all devices in the power domain are (runtime) suspended.

This patchset adds a GPC platform device initialized at subsys_initcall time
(after anatop regulators) that binds to the gpc device tree node and sets up
the PU power domain. The GPC node becomes a power-controller as defined by
Tomasz' OF power domain bindings. This series depends on the patches
    "drivercore: Bind/unbind power domain on probe/remove" and
    "base: power: Add generic OF-based power domain look-up".

Changes since v5:
 - Fixed compilation for !CONFIG_PM case
 - Added #define for clock array size
 - Keep "fsl,imx6q-gpc" compatible value for i.MX6SL gpc node

Philipp Zabel (5):
  Documentation: Add device tree bindings for Freescale i.MX GPC
  ARM: imx6: gpc: Add PU power domain for GPU/VPU
  ARM: dts: imx6qdl: Add power-domain information to gpc node
  ARM: dts: imx6sl: Add power-domain information to gpc node
  ARM: dts: imx6qdl: Allow disabling the PU regulator, add a enable ramp
    delay

 .../devicetree/bindings/power/fsl,imx-gpc.txt      |  54 ++++++
 arch/arm/boot/dts/imx6qdl.dtsi                     |   7 +-
 arch/arm/boot/dts/imx6sl.dtsi                      |   4 +
 arch/arm/mach-imx/Kconfig                          |   1 +
 arch/arm/mach-imx/gpc.c                            | 203 +++++++++++++++++++++
 5 files changed, 268 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/devicetree/bindings/power/fsl,imx-gpc.txt

-- 
1.9.0

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[PATCH v6 1/5] Documentation: Add device tree bindings for Freescale i.MX GPC

[Philipp Zabel]

The i.MX6 contains a power controller that controls power gating and
sequencing for the SoC's power domains.

Signed-off-by: Philipp Zabel <p.zabel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
---
 .../devicetree/bindings/power/fsl,imx-gpc.txt      | 54 ++++++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/power/fsl,imx-gpc.txt

diff --git a/Documentation/devicetree/bindings/power/fsl,imx-gpc.txt b/Documentation/devicetree/bindings/power/fsl,imx-gpc.txt
new file mode 100644
index 0000000..eaa8c93
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/fsl,imx-gpc.txt
@@ -0,0 +1,54 @@
+Freescale i.MX General Power Controller
+=======================================
+
+The i.MX6Q General Power Control (GPC) block contains DVFS load tracking
+counters and Power Gating Control (PGC) for the CPU and PU (GPU/VPU) power
+domains.
+
+Required properties:
+- compatible: Should be "fsl,imx6q-gpc" or "fsl,imx6sl-gpc"
+- reg: should be register base and length as documented in the
+  datasheet
+- interrupts: Should contain GPC interrupt request 1
+- pu-supply: Link to the LDO regulator powering the PU power domain
+- clocks: Clock phandles to devices in the PU power domain that need
+	  to be enabled during domain power-up for reset propagation.
+- #power-domain-cells: Should be 1, see below:
+
+The gpc node is a power-controller as documented by the generic power domain
+bindings in Documentation/devicetree/bindings/power/power_domain.txt.
+
+Example:
+
+	gpc: gpc@020dc000 {
+		compatible = "fsl,imx6q-gpc";
+		reg = <0x020dc000 0x4000>;
+		interrupts = <0 89 0x04 0 90 0x04>;
+		pu-supply = <&reg_pu>;
+		clocks = <&clks 122>, <&clks 74>, <&clks 121>,
+			 <&clks 26>, <&clks 143>, <&clks 168>;
+		#power-domain-cells = <1>;
+	};
+
+
+Specifying power domain for IP modules
+======================================
+
+IP cores belonging to a power domain should contain a 'power-domain' property
+that is a phandle pointing to the gpc device node and a DOMAIN_INDEX specifying
+the power domain the device belongs to.
+
+Example of a device that is part of the PU power domain:
+
+	vpu: vpu@02040000 {
+		reg = <0x02040000 0x3c000>;
+		/* ... */
+		power-domain = <&gpc 1>;
+		/* ... */
+	};
+
+The following DOMAIN_INDEX values are valid for i.MX6Q:
+ARM_DOMAIN     0
+PU_DOMAIN      1
+The following additional DOMAIN_INDEX value is valid for i.MX6SL:
+DISPLAY_DOMAIN 2
-- 
1.9.0

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[PATCH v6 2/5] ARM: imx6: gpc: Add PU power domain for GPU/VPU

[Philipp Zabel]

When generic pm domain support is enabled, the PGC can be used
to completely gate power to the PU power domain containing GPU3D,
GPU2D, and VPU cores.
This code triggers the PGC powerdown sequence to disable the GPU/VPU
isolation cells and gate power and then disables the PU regulator.
To reenable, the reverse powerup sequence is triggered after the PU
regulator is enabled again.
The GPU and VPU devices in the PU power domain temporarily need
to be clocked during powerup, so that the reset machinery can work.

Signed-off-by: Philipp Zabel <p.zabel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
---
Changes since v5:
 - Fixed compilation for !CONFIG_PM case
 - Added #define for clock array size
---
 arch/arm/mach-imx/Kconfig |   1 +
 arch/arm/mach-imx/gpc.c   | 203 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 204 insertions(+)

diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig
index 33567aa..a42fdad 100644
--- a/arch/arm/mach-imx/Kconfig
+++ b/arch/arm/mach-imx/Kconfig
@@ -57,6 +57,7 @@ config HAVE_IMX_ANATOP
 
 config HAVE_IMX_GPC
 	bool
+	select PM_GENERIC_DOMAINS if PM
 
 config HAVE_IMX_MMDC
 	bool
diff --git a/arch/arm/mach-imx/gpc.c b/arch/arm/mach-imx/gpc.c
index 586e017..7b1f5f4 100644
--- a/arch/arm/mach-imx/gpc.c
+++ b/arch/arm/mach-imx/gpc.c
@@ -10,19 +10,41 @@
  * http://www.gnu.org/copyleft/gpl.html
  */
 
+#include <linux/clk.h>
+#include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/irq.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/regulator/consumer.h>
 #include <linux/irqchip/arm-gic.h>
 #include "common.h"
+#include "hardware.h"
 
+#define GPC_CNTR		0x000
 #define GPC_IMR1		0x008
+#define GPC_PGC_GPU_PDN		0x260
+#define GPC_PGC_GPU_PUPSCR	0x264
+#define GPC_PGC_GPU_PDNSCR	0x268
 #define GPC_PGC_CPU_PDN		0x2a0
 
 #define IMR_NUM			4
 
+#define GPU_VPU_PUP_REQ		BIT(1)
+#define GPU_VPU_PDN_REQ		BIT(0)
+
+#define GPC_CLK_MAX		6
+
+struct pu_domain {
+	struct generic_pm_domain base;
+	struct regulator *reg;
+	struct clk *clk[GPC_CLK_MAX];
+	int num_clks;
+};
+
 static void __iomem *gpc_base;
 static u32 gpc_wake_irqs[IMR_NUM];
 static u32 gpc_saved_imrs[IMR_NUM];
@@ -138,3 +160,184 @@ void __init imx_gpc_init(void)
 	gic_arch_extn.irq_unmask = imx_gpc_irq_unmask;
 	gic_arch_extn.irq_set_wake = imx_gpc_irq_set_wake;
 }
+
+#ifdef CONFIG_PM
+
+static int imx6q_pm_pu_power_off(struct generic_pm_domain *genpd)
+{
+	struct pu_domain *pu = container_of(genpd, struct pu_domain, base);
+	int iso, iso2sw;
+	u32 val;
+
+	/* Read ISO and ISO2SW power down delays */
+	val = readl_relaxed(gpc_base + GPC_PGC_GPU_PDNSCR);
+	iso = val & 0x3f;
+	iso2sw = (val >> 8) & 0x3f;
+
+	/* Gate off PU domain when GPU/VPU when powered down */
+	writel_relaxed(0x1, gpc_base + GPC_PGC_GPU_PDN);
+
+	/* Request GPC to power down GPU/VPU */
+	val = readl_relaxed(gpc_base + GPC_CNTR);
+	val |= GPU_VPU_PDN_REQ;
+	writel_relaxed(val, gpc_base + GPC_CNTR);
+
+	/* Wait ISO + ISO2SW IPG clock cycles */
+	ndelay((iso + iso2sw) * 1000 / 66);
+
+	regulator_disable(pu->reg);
+
+	return 0;
+}
+
+static int imx6q_pm_pu_power_on(struct generic_pm_domain *genpd)
+{
+	struct pu_domain *pu = container_of(genpd, struct pu_domain, base);
+	int i, ret, sw, sw2iso;
+	u32 val;
+
+	ret = regulator_enable(pu->reg);
+	if (ret) {
+		pr_err("%s: failed to enable regulator: %d\n", __func__, ret);
+		return ret;
+	}
+
+	/* Enable reset clocks for all devices in the PU domain */
+	for (i = 0; i < pu->num_clks; i++)
+		clk_prepare_enable(pu->clk[i]);
+
+	/* Gate off PU domain when GPU/VPU when powered down */
+	writel_relaxed(0x1, gpc_base + GPC_PGC_GPU_PDN);
+
+	/* Read ISO and ISO2SW power down delays */
+	val = readl_relaxed(gpc_base + GPC_PGC_GPU_PUPSCR);
+	sw = val & 0x3f;
+	sw2iso = (val >> 8) & 0x3f;
+
+	/* Request GPC to power up GPU/VPU */
+	val = readl_relaxed(gpc_base + GPC_CNTR);
+	val |= GPU_VPU_PUP_REQ;
+	writel_relaxed(val, gpc_base + GPC_CNTR);
+
+	/* Wait ISO + ISO2SW IPG clock cycles */
+	ndelay((sw + sw2iso) * 1000 / 66);
+
+	/* Disable reset clocks for all devices in the PU domain */
+	for (i = 0; i < pu->num_clks; i++)
+		clk_disable_unprepare(pu->clk[i]);
+
+	return 0;
+}
+
+static struct generic_pm_domain imx6q_arm_domain = {
+	.name = "ARM",
+};
+
+static struct pu_domain imx6q_pu_domain = {
+	.base = {
+		.name = "PU",
+		.power_off = imx6q_pm_pu_power_off,
+		.power_on = imx6q_pm_pu_power_on,
+		.power_off_latency_ns = 25000,
+		.power_on_latency_ns = 2000000,
+	},
+};
+
+static struct generic_pm_domain imx6sl_display_domain = {
+	.name = "DISPLAY",
+};
+
+static struct generic_pm_domain *imx_gpc_domains[] = {
+	&imx6q_arm_domain,
+	&imx6q_pu_domain.base,
+	&imx6sl_display_domain,
+};
+
+static struct genpd_onecell_data imx_gpc_onecell_data = {
+	.domains = imx_gpc_domains,
+	.domain_num = ARRAY_SIZE(imx_gpc_domains),
+};
+
+static int imx_gpc_genpd_init(struct device *dev, struct regulator *pu_reg)
+{
+	struct clk *clk;
+	bool is_off;
+	int i;
+
+	imx6q_pu_domain.base.of_node = dev->of_node;
+	imx6q_pu_domain.reg = pu_reg;
+
+	for (i = 0; ; i++) {
+		clk = of_clk_get(dev->of_node, i);
+		if (IS_ERR(clk))
+			break;
+		if (i >= GPC_CLK_MAX) {
+			dev_err(dev, "more than %d clocks\n", GPC_CLK_MAX);
+			goto clk_err;
+		}
+		imx6q_pu_domain.clk[i] = clk;
+	}
+	imx6q_pu_domain.num_clks = i;
+
+	is_off = IS_ENABLED(CONFIG_PM_RUNTIME);
+	if (is_off)
+		imx6q_pm_pu_power_off(&imx6q_pu_domain.base);
+
+	pm_genpd_init(&imx6q_pu_domain.base, NULL, is_off);
+	return of_genpd_add_provider(dev->of_node, of_genpd_xlate_onecell,
+				     &imx_gpc_onecell_data);
+
+clk_err:
+	while (i--)
+		clk_put(imx6q_pu_domain.clk[i]);
+	return -EINVAL;
+}
+
+#else
+static inline int imx_gpc_genpd_init(struct device *dev, struct regulator *reg)
+{
+	return 0;
+}
+#endif /* CONFIG_PM */
+
+static int imx_gpc_probe(struct platform_device *pdev)
+{
+	struct regulator *pu_reg;
+	int ret;
+
+	pu_reg = devm_regulator_get(&pdev->dev, "pu");
+	if (IS_ERR(pu_reg)) {
+		ret = PTR_ERR(pu_reg);
+		dev_err(&pdev->dev, "failed to get pu regulator: %d\n", ret);
+		return ret;
+	}
+
+	/* The regulator is initially enabled */
+	ret = regulator_enable(pu_reg);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to enable pu regulator: %d\n", ret);
+		return ret;
+	}
+	return imx_gpc_genpd_init(&pdev->dev, pu_reg);
+}
+
+static struct of_device_id imx_gpc_dt_ids[] = {
+	{ .compatible = "fsl,imx6q-gpc" },
+	{ .compatible = "fsl,imx6sl-gpc" },
+	{ }
+};
+
+static struct platform_driver imx_gpc_driver = {
+	.driver = {
+		.name = "imx-gpc",
+		.owner = THIS_MODULE,
+		.of_match_table = imx_gpc_dt_ids,
+	},
+	.probe = imx_gpc_probe,
+};
+
+static int __init imx_pgc_init(void)
+{
+	return platform_driver_register(&imx_gpc_driver);
+}
+subsys_initcall(imx_pgc_init);
-- 
1.9.0

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[PATCH v6 3/5] ARM: dts: imx6qdl: Add power-domain information to gpc node

[Philipp Zabel]

The PGC that is part of GPC controls isolation and power sequencing of the
power domains. The PU power domain will be handled by the generic pm domain
framework. It needs a phandle to the PU regulator to turn off power when
the domain is disabled, and a list of phandles to all clocks that must be
enabled during powerup for reset propagation.

Signed-off-by: Philipp Zabel <p.zabel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
---
 arch/arm/boot/dts/imx6qdl.dtsi | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm/boot/dts/imx6qdl.dtsi b/arch/arm/boot/dts/imx6qdl.dtsi
index fb28b2e..00f0bf0 100644
--- a/arch/arm/boot/dts/imx6qdl.dtsi
+++ b/arch/arm/boot/dts/imx6qdl.dtsi
@@ -600,6 +600,10 @@
 				compatible = "fsl,imx6q-gpc";
 				reg = <0x020dc000 0x4000>;
 				interrupts = <0 89 0x04 0 90 0x04>;
+				pu-supply = <&reg_pu>;
+				clocks = <&clks 122>, <&clks 74>, <&clks 121>,
+					 <&clks 26>, <&clks 143>, <&clks 168>;
+				#power-domain-cells = <1>;
 			};
 
 			gpr: iomuxc-gpr@020e0000 {
-- 
1.9.0

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[PATCH v6 4/5] ARM: dts: imx6sl: Add power-domain information to gpc node

[Philipp Zabel]

The PGC that is part of GPC controls isolation and power sequencing of the
power domains. The PU power domain will be handled by the generic pm domain
framework. It needs a phandle to the PU regulator to turn off power when
the domain is disabled and a list of clocks to be enabled during powerup
for reset propagation.

Signed-off-by: Philipp Zabel <p.zabel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
---
Changes since v5:
 - Keep "fsl,imx6q-gpc" compatible value
---
 arch/arm/boot/dts/imx6sl.dtsi | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm/boot/dts/imx6sl.dtsi b/arch/arm/boot/dts/imx6sl.dtsi
index 28558f1..d3d8cf9 100644
--- a/arch/arm/boot/dts/imx6sl.dtsi
+++ b/arch/arm/boot/dts/imx6sl.dtsi
@@ -532,6 +532,10 @@
 				compatible = "fsl,imx6sl-gpc", "fsl,imx6q-gpc";
 				reg = <0x020dc000 0x4000>;
 				interrupts = <0 89 0x04>;
+				pu-supply = <&reg_pu>;
+				clocks = <&clks IMX6SL_CLK_GPU2D_OVG>,
+					 <&clks IMX6SL_CLK_GPU2D_PODF>;
+				#power-domain-cells = <1>;
 			};
 
 			gpr: iomuxc-gpr@020e0000 {
-- 
1.9.0

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[PATCH v6 5/5] ARM: dts: imx6qdl: Allow disabling the PU regulator, add a enable ramp delay

[Philipp Zabel]

The PU regulator is enabled during boot, but not necessarily always-on.
It can be disabled by the generic pm domain framework when the PU power
domain is shut down. The ramp delay of 150 us might be a bit conservative,
the value is taken from the Freescale kernel.

Signed-off-by: Philipp Zabel <p.zabel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
---
 arch/arm/boot/dts/imx6qdl.dtsi | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/imx6qdl.dtsi b/arch/arm/boot/dts/imx6qdl.dtsi
index 00f0bf0..57e990e 100644
--- a/arch/arm/boot/dts/imx6qdl.dtsi
+++ b/arch/arm/boot/dts/imx6qdl.dtsi
@@ -515,7 +515,8 @@
 					regulator-name = "vddpu";
 					regulator-min-microvolt = <725000>;
 					regulator-max-microvolt = <1450000>;
-					regulator-always-on;
+					regulator-enable-ramp-delay = <150>;
+					regulator-boot-on;
 					anatop-reg-offset = <0x140>;
 					anatop-vol-bit-shift = <9>;
 					anatop-vol-bit-width = <5>;
-- 
1.9.0

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