On Fri, Feb 02, 2024 at 01:12:41PM +0100, Lorenzo Pieralisi wrote:

"PCI: imx6: Use "linux,pci-domain" as slot ID"

On Fri, Jan 19, 2024 at 12:11:11PM -0500, Frank Li wrote:

quoted

Avoid use get slot id by compared with register physical address. If there
are more than 2 slots, compared logic will become complex.

"linux,pci-domain" already exist at dts since commit:
	commit (c0b70f05c87f3b arm64: dts: imx8mq: use_dt_domains for pci node).

So it is safe to remove compare basic address code:
	...
	if (dbi_base->start == IMX8MQ_PCIE2_BASE_ADDR)
		imx6_pcie->controller_id = 1;

No it is not unless you magically update all firmware out
there in the field.

commit c0b70f05c87f3b09b391027c6f056d0facf331ef
Author:     Peng Fan [off-list ref]
AuthorDate: Fri Jan 15 11:26:57 2021 +0800
Commit:     Shawn Guo [off-list ref]
CommitDate: Fri Jan 29 14:46:28 2021 +0800

I am not sure if it is neccesary to compatible with 2 years ago's dts.
I think it may not boot at all with using 2 year agao dtb file directly.

Do you have other comments? I can remove it from this big patch series,

Frank

quoted

	...

Reviewed-by: Manivannan Sadhasivam <redacted>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---

Notes:
    Change from v7 to v8
    - fixed comments
    - Added Manivannan Sadhasivam's review tag
    Change from v5 to v7
    - none
    Change from v3 to v4
    - remove compare basic address logic
    Change from v2 to v3
    - none
    Change from v1 to v2
    - fix of_get_pci_domain_nr return value check logic

 drivers/pci/controller/dwc/pci-imx6.c | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index eda6bc6ef80ee..773411d20329f 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c

@@ -33,6 +33,7 @@
 #include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
 
+#include "../../pci.h"
 #include "pcie-designware.h"
 
 #define IMX8MQ_GPR_PCIE_REF_USE_PAD		BIT(9)

@@ -40,7 +41,6 @@
 #define IMX8MQ_GPR_PCIE_CLK_REQ_OVERRIDE	BIT(11)
 #define IMX8MQ_GPR_PCIE_VREG_BYPASS		BIT(12)
 #define IMX8MQ_GPR12_PCIE2_CTRL_DEVICE_TYPE	GENMASK(11, 8)
-#define IMX8MQ_PCIE2_BASE_ADDR			0x33c00000
 
 #define to_imx6_pcie(x)	dev_get_drvdata((x)->dev)
 

@@ -1279,13 +1279,17 @@ static int imx6_pcie_probe(struct platform_device *pdev)
 					     "Failed to get PCIEPHY reset control\n");
 	}
 
-	switch (imx6_pcie->drvdata->variant) {
-	case IMX7D:
-		if (dbi_base->start == IMX8MQ_PCIE2_BASE_ADDR)
-			imx6_pcie->controller_id = 1;
-	default:
-		break;
-	}
+	/* Using linux,pci-domain as PCI slot id */
+	imx6_pcie->controller_id = of_get_pci_domain_nr(node);
+	/*
+	 * If there are no "linux,pci-domain" property specified in DT, then assume only one
+	 * controller is available.
+	 */
+	if (imx6_pcie->controller_id == -EINVAL)
+		imx6_pcie->controller_id = 0;

See above, this breaks compatibility with old DTs (and -EINVAL is not
the only error code you should handle).

Lorenzo

quoted

+	else if (imx6_pcie->controller_id < 0)
+		return dev_err_probe(dev, imx6_pcie->controller_id,
+				     "linux,pci-domain have wrong value\n");
 
 	/* Grab turnoff reset */
 	imx6_pcie->turnoff_reset = devm_reset_control_get_optional_exclusive(dev, "turnoff");
-- 
2.34.1

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