[PATCH 0/3] ARM: dts: imx6sx: Add DISPLAY power domain support

[PATCH 0/3] ARM: dts: imx6sx: Add DISPLAY power domain support

[Leonard Crestez]

Now that mxsfb has functional runtime_pm support we can enable power
gating for the DISPLAY power domain on imx6sx.

Since pci-imx doesn't support runtime power gating this is still
always-on unless PCI is disabled/unused. But it's reasonable for an imx
board to not have PCI.

The current pd_pcie is actually only for PCIE_PHY, the PCIE ip block is
actually inside the DISPLAY domain. This is handled by adding the pcie
node in both power domains, using multi-pd support.

Series is against linux-next. The last patch needs runtime PM in all
drivers or it will cause hangs. This means Shawn should hold back on it
until the PCI and mxsfb dependencies get merged (both might take a long
time). So you can just review that patch and I will resend it later,
perhaps in another cycle.

Link to mxsfb thread: https://lkml.org/lkml/2018/9/26/1185

Leonard Crestez (3):
  soc: imx: gpc: Increase GPC_CLK_MAX to 7
  PCI: imx: Add multi-pd support
  ARM: dts: imx6sx: Add DISPLAY power domain support

 arch/arm/boot/dts/imx6sx.dtsi         | 19 ++++++++++-
 drivers/pci/controller/dwc/pci-imx6.c | 48 +++++++++++++++++++++++++++
 drivers/soc/imx/gpc.c                 |  2 +-
 3 files changed, 67 insertions(+), 2 deletions(-)

-- 
2.17.1

[PATCH 1/3] soc: imx: gpc: Increase GPC_CLK_MAX to 7

[Leonard Crestez]

The DISPLAY power domain on imx6sx has 7 clocks.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
---
 drivers/soc/imx/gpc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/soc/imx/gpc.c b/drivers/soc/imx/gpc.c
index c1d0ffdac6dd..51cbfe63ec12 100644
--- a/drivers/soc/imx/gpc.c
+++ b/drivers/soc/imx/gpc.c
@@ -39,11 +39,11 @@
 #define GPC_PGC_DISP_SR		0x24c
 
 #define GPU_VPU_PUP_REQ		BIT(1)
 #define GPU_VPU_PDN_REQ		BIT(0)
 
-#define GPC_CLK_MAX		6
+#define GPC_CLK_MAX		7
 
 #define PGC_DOMAIN_FLAG_NO_PD		BIT(0)
 
 struct imx_pm_domain {
 	struct generic_pm_domain base;
-- 
2.17.1

[PATCH 2/3] PCI: imx: Add multi-pd support

[Leonard Crestez]

On some chips the PCIE and PCIE_PHY blocks are in separate power domains
which can be power-gated independently. The driver needs to handle this
by keeping both domain active.

This is intended for imx6sx where PCIE is in DISPMIX and PCIE_PHY in
it's own domain. Defining the DISPMIX domain requires a way for pcie to
keep it active or it will break when displays are off.

The power-domains on imx6sx are meant to look like this:
	power-domains = <&pd_disp>, <&pd_pci>;
	power-domain-names = "pcie", "pcie_phy";

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

---
 drivers/pci/controller/dwc/pci-imx6.c | 48 +++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

Previously sent as RFC: https://lkml.org/lkml/2018/7/24/849

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index d13dae50dc99..6ba16fd1373c 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -25,10 +25,12 @@
 #include <linux/resource.h>
 #include <linux/signal.h>
 #include <linux/types.h>
 #include <linux/interrupt.h>
 #include <linux/reset.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
 
 #include "pcie-designware.h"
 
 #define to_imx6_pcie(x)	dev_get_drvdata((x)->dev)
 
@@ -56,10 +58,15 @@ struct imx6_pcie {
 	u32			tx_deemph_gen2_6db;
 	u32			tx_swing_full;
 	u32			tx_swing_low;
 	int			link_gen;
 	struct regulator	*vpcie;
+
+	/* power domain for pcie itself (dispmix) */
+	struct device		*pd_pcie;
+	/* power domain for pcie phy */
+	struct device		*pd_pcie_phy;
 };
 
 /* Parameters for the waiting for PCIe PHY PLL to lock on i.MX7 */
 #define PHY_PLL_LOCK_WAIT_MAX_RETRIES	2000
 #define PHY_PLL_LOCK_WAIT_USLEEP_MIN	50
@@ -289,10 +296,47 @@ static int imx6q_pcie_abort_handler(unsigned long addr,
 	}
 
 	return 1;
 }
 
+static int imx6_pcie_attach_pd(struct device *dev)
+{
+	struct imx6_pcie *imx6_pcie = dev_get_drvdata(dev);
+	struct device_link *link;
+
+	/* Do nothing when in a single power domain */
+	if (dev->pm_domain)
+		return 0;
+
+	imx6_pcie->pd_pcie = dev_pm_domain_attach_by_name(dev, "pcie");
+	if (IS_ERR(imx6_pcie->pd_pcie))
+		return PTR_ERR(imx6_pcie->pd_pcie);
+	link = device_link_add(dev, imx6_pcie->pd_pcie,
+			DL_FLAG_STATELESS |
+			DL_FLAG_PM_RUNTIME |
+			DL_FLAG_RPM_ACTIVE);
+	if (IS_ERR(link)) {
+		dev_err(dev, "Failed to add device_link to pcie pd: %ld\n", PTR_ERR(link));
+		return PTR_ERR(link);
+	}
+
+	imx6_pcie->pd_pcie_phy = dev_pm_domain_attach_by_name(dev, "pcie_phy");
+	if (IS_ERR(imx6_pcie->pd_pcie_phy))
+		return PTR_ERR(imx6_pcie->pd_pcie_phy);
+
+	device_link_add(dev, imx6_pcie->pd_pcie_phy,
+			DL_FLAG_STATELESS |
+			DL_FLAG_PM_RUNTIME |
+			DL_FLAG_RPM_ACTIVE);
+	if (IS_ERR(link)) {
+		dev_err(dev, "Failed to add device_link to pcie_phy pd: %ld\n", PTR_ERR(link));
+		return PTR_ERR(link);
+	}
+
+	return 0;
+}
+
 static void imx6_pcie_assert_core_reset(struct imx6_pcie *imx6_pcie)
 {
 	struct device *dev = imx6_pcie->pci->dev;
 
 	switch (imx6_pcie->variant) {
@@ -959,10 +1003,14 @@ static int imx6_pcie_probe(struct platform_device *pdev)
 		imx6_pcie->vpcie = NULL;
 	}
 
 	platform_set_drvdata(pdev, imx6_pcie);
 
+	ret = imx6_pcie_attach_pd(dev);
+	if (ret)
+		return ret;
+
 	ret = imx6_add_pcie_port(imx6_pcie, pdev);
 	if (ret < 0)
 		return ret;
 
 	return 0;
-- 
2.17.1

[PATCH 3/3] ARM: dts: imx6sx: Add DISPLAY power domain support

[Leonard Crestez]

This was implemented in the driver but not actually defined and
referenced in dts. This makes it always on.

From reference manual in section "10.4.1.4.1 Power Distribution":

"Display domain - The DISPLAY domain contains GIS, CSI, PXP, LCDIF,
PCIe, DCIC, and LDB. It is supplied by internal regulator."

The current pd_pcie is actually only for PCIE_PHY, the PCIE ip block is
actually inside the DISPLAY domain. Handle this by adding the pcie node
in both power domains.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
---
 arch/arm/boot/dts/imx6sx.dtsi | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/imx6sx.dtsi b/arch/arm/boot/dts/imx6sx.dtsi
index 844caa39364f..054d812bcdbc 100644
--- a/arch/arm/boot/dts/imx6sx.dtsi
+++ b/arch/arm/boot/dts/imx6sx.dtsi
@@ -778,10 +778,22 @@
 						#power-domain-cells = <0>;
 						power-supply = <&reg_soc>;
 						clocks = <&clks IMX6SX_CLK_GPU>;
 					};
 
+					pd_disp: power-domain@2 {
+						reg = <2>;
+						#power-domain-cells = <0>;
+						clocks = <&clks IMX6SX_CLK_PXP_AXI>,
+							 <&clks IMX6SX_CLK_DISPLAY_AXI>,
+							 <&clks IMX6SX_CLK_LCDIF1_PIX>,
+							 <&clks IMX6SX_CLK_LCDIF_APB>,
+							 <&clks IMX6SX_CLK_LCDIF2_PIX>,
+							 <&clks IMX6SX_CLK_CSI>,
+							 <&clks IMX6SX_CLK_VADC>;
+					};
+
 					pd_pci: power-domain@3 {
 						reg = <3>;
 						#power-domain-cells = <0>;
 						power-supply = <&reg_pcie>;
 					};
@@ -1196,10 +1208,11 @@
 					reg = <0x02218000 0x4000>;
 					interrupts = <GIC_SPI 8 IRQ_TYPE_LEVEL_HIGH>;
 					clocks = <&clks IMX6SX_CLK_PXP_AXI>,
 						 <&clks IMX6SX_CLK_DISPLAY_AXI>;
 					clock-names = "pxp-axi", "disp-axi";
+					power-domains = <&pd_disp>;
 					status = "disabled";
 				};
 
 				csi2: csi@221c000 {
 					reg = <0x0221c000 0x4000>;
@@ -1217,10 +1230,11 @@
 					interrupts = <GIC_SPI 5 IRQ_TYPE_EDGE_RISING>;
 					clocks = <&clks IMX6SX_CLK_LCDIF1_PIX>,
 						 <&clks IMX6SX_CLK_LCDIF_APB>,
 						 <&clks IMX6SX_CLK_DISPLAY_AXI>;
 					clock-names = "pix", "axi", "disp_axi";
+					power-domains = <&pd_disp>;
 					status = "disabled";
 				};
 
 				lcdif2: lcdif@2224000 {
 					compatible = "fsl,imx6sx-lcdif", "fsl,imx28-lcdif";
@@ -1228,19 +1242,21 @@
 					interrupts = <GIC_SPI 6 IRQ_TYPE_EDGE_RISING>;
 					clocks = <&clks IMX6SX_CLK_LCDIF2_PIX>,
 						 <&clks IMX6SX_CLK_LCDIF_APB>,
 						 <&clks IMX6SX_CLK_DISPLAY_AXI>;
 					clock-names = "pix", "axi", "disp_axi";
+					power-domains = <&pd_disp>;
 					status = "disabled";
 				};
 
 				vadc: vadc@2228000 {
 					reg = <0x02228000 0x4000>, <0x0222c000 0x4000>;
 					reg-names = "vadc-vafe", "vadc-vdec";
 					clocks = <&clks IMX6SX_CLK_VADC>,
 						 <&clks IMX6SX_CLK_CSI>;
 					clock-names = "vadc", "csi";
+					power-domains = <&pd_disp>;
 					status = "disabled";
 				};
 			};
 
 			adc1: adc@2280000 {
@@ -1361,10 +1377,11 @@
 			clocks = <&clks IMX6SX_CLK_PCIE_AXI>,
 				 <&clks IMX6SX_CLK_LVDS1_OUT>,
 				 <&clks IMX6SX_CLK_PCIE_REF_125M>,
 				 <&clks IMX6SX_CLK_DISPLAY_AXI>;
 			clock-names = "pcie", "pcie_bus", "pcie_phy", "pcie_inbound_axi";
-			power-domains = <&pd_pci>;
+			power-domains = <&pd_disp>, <&pd_pci>;
+			power-domain-names = "pcie", "pcie_phy";
 			status = "disabled";
 		};
 	};
 };
-- 
2.17.1

Re: [PATCH 2/3] PCI: imx: Add multi-pd support

[Shawn Guo]

On Mon, Oct 01, 2018 at 11:56:17PM +0300, Leonard Crestez wrote:
> On some chips the PCIE and PCIE_PHY blocks are in separate power domains
> which can be power-gated independently. The driver needs to handle this
> by keeping both domain active.
> 
> This is intended for imx6sx where PCIE is in DISPMIX and PCIE_PHY in
> it's own domain. Defining the DISPMIX domain requires a way for pcie to
> keep it active or it will break when displays are off.
> 
> The power-domains on imx6sx are meant to look like this:
> 	power-domains = <&pd_disp>, <&pd_pci>;
> 	power-domain-names = "pcie", "pcie_phy";
> 
> Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
> 
> ---
>  drivers/pci/controller/dwc/pci-imx6.c | 48 +++++++++++++++++++++++++++
>  1 file changed, 48 insertions(+)

Bindings document fsl,imx6q-pcie.txt should probably be updated for the
new power domain support.

Shawn