[PATCH v2 2/2] PCI: tegra: Remove PLL power supplies

From: Thierry Reding <redacted>

The Tegra PCI controller driver doesn't need to control the PLL power
supplies directly, but rather uses the pads provided by the XUSB pad
controller, which in turn is responsible for supplying power to the
PLLs.

Signed-off-by: Thierry Reding <redacted>
---
 drivers/pci/controller/pci-tegra.c | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c
index 235b456698fc..f87a09d21eb0 100644
--- a/drivers/pci/controller/pci-tegra.c
+++ b/drivers/pci/controller/pci-tegra.c

@@ -2025,7 +2025,7 @@ static int tegra_pcie_get_regulators(struct tegra_pcie *pcie, u32 lane_mask)
 		pcie->supplies[i++].supply = "hvdd-pex";
 		pcie->supplies[i++].supply = "vddio-pexctl-aud";
 	} else if (of_device_is_compatible(np, "nvidia,tegra210-pcie")) {
-		pcie->num_supplies = 6;
+		pcie->num_supplies = 3;
 
 		pcie->supplies = devm_kcalloc(pcie->dev, pcie->num_supplies,
 					      sizeof(*pcie->supplies),

@@ -2033,14 +2033,11 @@ static int tegra_pcie_get_regulators(struct tegra_pcie *pcie, u32 lane_mask)
 		if (!pcie->supplies)
 			return -ENOMEM;
 
-		pcie->supplies[i++].supply = "avdd-pll-uerefe";
 		pcie->supplies[i++].supply = "hvddio-pex";
 		pcie->supplies[i++].supply = "dvddio-pex";
-		pcie->supplies[i++].supply = "dvdd-pex-pll";
-		pcie->supplies[i++].supply = "hvdd-pex-pll-e";
 		pcie->supplies[i++].supply = "vddio-pex-ctl";
 	} else if (of_device_is_compatible(np, "nvidia,tegra124-pcie")) {
-		pcie->num_supplies = 7;
+		pcie->num_supplies = 4;
 
 		pcie->supplies = devm_kcalloc(dev, pcie->num_supplies,
 					      sizeof(*pcie->supplies),

@@ -2050,11 +2047,8 @@ static int tegra_pcie_get_regulators(struct tegra_pcie *pcie, u32 lane_mask)
 
 		pcie->supplies[i++].supply = "avddio-pex";
 		pcie->supplies[i++].supply = "dvddio-pex";
-		pcie->supplies[i++].supply = "avdd-pex-pll";
 		pcie->supplies[i++].supply = "hvdd-pex";
-		pcie->supplies[i++].supply = "hvdd-pex-pll-e";
 		pcie->supplies[i++].supply = "vddio-pex-ctl";
-		pcie->supplies[i++].supply = "avdd-pll-erefe";
 	} else if (of_device_is_compatible(np, "nvidia,tegra30-pcie")) {
 		bool need_pexa = false, need_pexb = false;
 

-- 
2.27.0

On Tue, Jun 23, 2020 at 8:55 AM Thierry Reding [off-list ref] wrote:

From: Thierry Reding <redacted>

The Tegra PCI controller driver doesn't need to control the PLL power
supplies directly, but rather uses the pads provided by the XUSB pad
controller, which in turn is responsible for supplying power to the
PLLs.

Signed-off-by: Thierry Reding <redacted>
---
 drivers/pci/controller/pci-tegra.c | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

What's going to happen here with a new dtb and an old kernel? Is it
going to error out due to missing supplies?

Rob

On Mon, Jul 27, 2020 at 10:21:42AM -0600, Rob Herring wrote:

On Tue, Jun 23, 2020 at 8:55 AM Thierry Reding [off-list ref] wrote:

quoted

From: Thierry Reding <redacted>

The Tegra PCI controller driver doesn't need to control the PLL power
supplies directly, but rather uses the pads provided by the XUSB pad
controller, which in turn is responsible for supplying power to the
PLLs.

Signed-off-by: Thierry Reding <redacted>
---
 drivers/pci/controller/pci-tegra.c | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

What's going to happen here with a new dtb and an old kernel? Is it
going to error out due to missing supplies?

It's not going to error out but fallback to the "dummy" regulator, so
this should be fine from a forwards-compatibility point of view. Though
I didn't think we technically cared about that direction very much.

Thierry

On Mon, Jul 27, 2020 at 11:21 AM Thierry Reding
[off-list ref] wrote:

On Mon, Jul 27, 2020 at 10:21:42AM -0600, Rob Herring wrote:

quoted

On Tue, Jun 23, 2020 at 8:55 AM Thierry Reding [off-list ref] wrote:

quoted

From: Thierry Reding <redacted>

The Tegra PCI controller driver doesn't need to control the PLL power
supplies directly, but rather uses the pads provided by the XUSB pad
controller, which in turn is responsible for supplying power to the
PLLs.

Signed-off-by: Thierry Reding <redacted>
---
 drivers/pci/controller/pci-tegra.c | 10 ++--------
 1 file changed, 2 insertions(+), 8 deletions(-)

What's going to happen here with a new dtb and an old kernel? Is it
going to error out due to missing supplies?

It's not going to error out but fallback to the "dummy" regulator, so
this should be fine from a forwards-compatibility point of view. Though
I didn't think we technically cared about that direction very much.

AIUI, SUSE ships newer DTs with stable kernels. Of course, the dtb's
shouldn't really come from the OS vendors, but you wouldn't want a
newer firmware (w/ dtb) to break your OS either.

In any case,

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

Rob