Combine machine descriptions and code of all P2020 boards into just one
generic unified P2020 machine description. This allows kernel to boot on
any P2020-based board with P2020 DTS file without need to patch kernel and
define a new machine description in 85xx powerpc platform directory.

Signed-off-by: Pali Rohár <pali@kernel.org>
---
 arch/powerpc/platforms/85xx/p2020.c | 83 +++++++----------------------
 1 file changed, 19 insertions(+), 64 deletions(-)

diff --git a/arch/powerpc/platforms/85xx/p2020.c b/arch/powerpc/platforms/85xx/p2020.c
index d327e6c9b838..1a3ffeb47dfc 100644
--- a/arch/powerpc/platforms/85xx/p2020.c
+++ b/arch/powerpc/platforms/85xx/p2020.c
@@ -154,83 +154,38 @@ static void __init p2020_setup_arch(void)
 #endif
 }
 
-#ifdef CONFIG_MPC85xx_DS
-machine_arch_initcall(p2020_ds, mpc85xx_common_publish_devices);
-#endif /* CONFIG_MPC85xx_DS */
-
-#ifdef CONFIG_MPC85xx_RDB
-machine_arch_initcall(p2020_rdb, mpc85xx_common_publish_devices);
-machine_arch_initcall(p2020_rdb_pc, mpc85xx_common_publish_devices);
-#endif /* CONFIG_MPC85xx_RDB */
+machine_arch_initcall(p2020, mpc85xx_common_publish_devices);
 
 /*
  * Called very early, device-tree isn't unflattened
  */
-#ifdef CONFIG_MPC85xx_DS
-static int __init p2020_ds_probe(void)
-{
-	return !!of_machine_is_compatible("fsl,P2020DS");
-}
-#endif /* CONFIG_MPC85xx_DS */
-
-#ifdef CONFIG_MPC85xx_RDB
-static int __init p2020_rdb_probe(void)
-{
-	if (of_machine_is_compatible("fsl,P2020RDB"))
-		return 1;
-	return 0;
-}
-
-static int __init p2020_rdb_pc_probe(void)
+static int __init p2020_probe(void)
 {
-	if (of_machine_is_compatible("fsl,P2020RDB-PC"))
-		return 1;
-	return 0;
+	struct device_node *p2020_cpu;
+
+	/*
+	 * There is no common compatible string for all P2020 boards.
+	 * The only common thing is "PowerPC,P2020@0" cpu node.
+	 * So check for P2020 board via this cpu node.
+	 */
+	p2020_cpu = of_find_node_by_path("/cpus/PowerPC,P2020@0");
+	if (!p2020_cpu)
+		return 0;
+
+	of_node_put(p2020_cpu);
+	return 1;
 }
-#endif /* CONFIG_MPC85xx_RDB */
-
-#ifdef CONFIG_MPC85xx_DS
-define_machine(p2020_ds) {
-	.name			= "P2020 DS",
-	.probe			= p2020_ds_probe,
-	.setup_arch		= p2020_setup_arch,
-	.init_IRQ		= p2020_pic_init,
-#ifdef CONFIG_PCI
-	.pcibios_fixup_bus	= fsl_pcibios_fixup_bus,
-	.pcibios_fixup_phb      = fsl_pcibios_fixup_phb,
-#endif
-	.get_irq		= mpic_get_irq,
-	.calibrate_decr		= generic_calibrate_decr,
-	.progress		= udbg_progress,
-};
-#endif /* CONFIG_MPC85xx_DS */
-
-#ifdef CONFIG_MPC85xx_RDB
-define_machine(p2020_rdb) {
-	.name			= "P2020 RDB",
-	.probe			= p2020_rdb_probe,
-	.setup_arch		= p2020_setup_arch,
-	.init_IRQ		= p2020_pic_init,
-#ifdef CONFIG_PCI
-	.pcibios_fixup_bus	= fsl_pcibios_fixup_bus,
-	.pcibios_fixup_phb      = fsl_pcibios_fixup_phb,
-#endif
-	.get_irq		= mpic_get_irq,
-	.calibrate_decr		= generic_calibrate_decr,
-	.progress		= udbg_progress,
-};
 
-define_machine(p2020_rdb_pc) {
-	.name			= "P2020RDB-PC",
-	.probe			= p2020_rdb_pc_probe,
+define_machine(p2020) {
+	.name			= "Freescale P2020",
+	.probe			= p2020_probe,
 	.setup_arch		= p2020_setup_arch,
 	.init_IRQ		= p2020_pic_init,
 #ifdef CONFIG_PCI
 	.pcibios_fixup_bus	= fsl_pcibios_fixup_bus,
-	.pcibios_fixup_phb      = fsl_pcibios_fixup_phb,
+	.pcibios_fixup_phb	= fsl_pcibios_fixup_phb,
 #endif
 	.get_irq		= mpic_get_irq,
 	.calibrate_decr		= generic_calibrate_decr,
 	.progress		= udbg_progress,
 };
-#endif /* CONFIG_MPC85xx_RDB */
-- 
2.20.1

Le 19/08/2022 à 21:15, Pali Rohár a écrit :
> Combine machine descriptions and code of all P2020 boards into just one
> generic unified P2020 machine description. This allows kernel to boot on
> any P2020-based board with P2020 DTS file without need to patch kernel and
> define a new machine description in 85xx powerpc platform directory.
> 
> Signed-off-by: Pali Rohár <pali@kernel.org>
> ---
>   arch/powerpc/platforms/85xx/p2020.c | 83 +++++++----------------------
>   1 file changed, 19 insertions(+), 64 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/85xx/p2020.c b/arch/powerpc/platforms/85xx/p2020.c
> index d327e6c9b838..1a3ffeb47dfc 100644
> --- a/arch/powerpc/platforms/85xx/p2020.c
> +++ b/arch/powerpc/platforms/85xx/p2020.c
> @@ -154,83 +154,38 @@ static void __init p2020_setup_arch(void)
>   #endif
>   }
>   
> -#ifdef CONFIG_MPC85xx_DS
> -machine_arch_initcall(p2020_ds, mpc85xx_common_publish_devices);
> -#endif /* CONFIG_MPC85xx_DS */
> -
> -#ifdef CONFIG_MPC85xx_RDB
> -machine_arch_initcall(p2020_rdb, mpc85xx_common_publish_devices);
> -machine_arch_initcall(p2020_rdb_pc, mpc85xx_common_publish_devices);
> -#endif /* CONFIG_MPC85xx_RDB */
> +machine_arch_initcall(p2020, mpc85xx_common_publish_devices);
>   
>   /*
>    * Called very early, device-tree isn't unflattened
>    */
> -#ifdef CONFIG_MPC85xx_DS
> -static int __init p2020_ds_probe(void)
> -{
> -	return !!of_machine_is_compatible("fsl,P2020DS");
> -}
> -#endif /* CONFIG_MPC85xx_DS */
> -
> -#ifdef CONFIG_MPC85xx_RDB
> -static int __init p2020_rdb_probe(void)
> -{
> -	if (of_machine_is_compatible("fsl,P2020RDB"))
> -		return 1;
> -	return 0;
> -}
> -
> -static int __init p2020_rdb_pc_probe(void)
> +static int __init p2020_probe(void)
>   {
> -	if (of_machine_is_compatible("fsl,P2020RDB-PC"))
> -		return 1;
> -	return 0;
> +	struct device_node *p2020_cpu;
> +
> +	/*
> +	 * There is no common compatible string for all P2020 boards.
> +	 * The only common thing is "PowerPC,P2020@0" cpu node.
> +	 * So check for P2020 board via this cpu node.
> +	 */
> +	p2020_cpu = of_find_node_by_path("/cpus/PowerPC,P2020@0");
> +	if (!p2020_cpu)
> +		return 0;

This looks odd. I though all probe were using the compatible, and in 
fact I have a series in preparation that drops all 
of_machine_is_compatible() checks in probe functions and do it in the 
caller instead, after adding a .compatible string in the machine 
description.

Is there really no compatible that can be used for all p2020 ?

> +
> +	of_node_put(p2020_cpu);
> +	return 1;
>   }
> -#endif /* CONFIG_MPC85xx_RDB */
> -
> -#ifdef CONFIG_MPC85xx_DS
> -define_machine(p2020_ds) {
> -	.name			= "P2020 DS",
> -	.probe			= p2020_ds_probe,
> -	.setup_arch		= p2020_setup_arch,
> -	.init_IRQ		= p2020_pic_init,
> -#ifdef CONFIG_PCI
> -	.pcibios_fixup_bus	= fsl_pcibios_fixup_bus,
> -	.pcibios_fixup_phb      = fsl_pcibios_fixup_phb,
> -#endif
> -	.get_irq		= mpic_get_irq,
> -	.calibrate_decr		= generic_calibrate_decr,
> -	.progress		= udbg_progress,
> -};
> -#endif /* CONFIG_MPC85xx_DS */
> -
> -#ifdef CONFIG_MPC85xx_RDB
> -define_machine(p2020_rdb) {
> -	.name			= "P2020 RDB",
> -	.probe			= p2020_rdb_probe,
> -	.setup_arch		= p2020_setup_arch,
> -	.init_IRQ		= p2020_pic_init,
> -#ifdef CONFIG_PCI
> -	.pcibios_fixup_bus	= fsl_pcibios_fixup_bus,
> -	.pcibios_fixup_phb      = fsl_pcibios_fixup_phb,
> -#endif
> -	.get_irq		= mpic_get_irq,
> -	.calibrate_decr		= generic_calibrate_decr,
> -	.progress		= udbg_progress,
> -};
>   
> -define_machine(p2020_rdb_pc) {
> -	.name			= "P2020RDB-PC",
> -	.probe			= p2020_rdb_pc_probe,
> +define_machine(p2020) {
> +	.name			= "Freescale P2020",
> +	.probe			= p2020_probe,
>   	.setup_arch		= p2020_setup_arch,
>   	.init_IRQ		= p2020_pic_init,
>   #ifdef CONFIG_PCI
>   	.pcibios_fixup_bus	= fsl_pcibios_fixup_bus,
> -	.pcibios_fixup_phb      = fsl_pcibios_fixup_phb,
> +	.pcibios_fixup_phb	= fsl_pcibios_fixup_phb,
>   #endif
>   	.get_irq		= mpic_get_irq,
>   	.calibrate_decr		= generic_calibrate_decr,
>   	.progress		= udbg_progress,
>   };
> -#endif /* CONFIG_MPC85xx_RDB */

On Monday 26 September 2022 10:02:47 Christophe Leroy wrote:
> > +static int __init p2020_probe(void)
> >   {
> > -	if (of_machine_is_compatible("fsl,P2020RDB-PC"))
> > -		return 1;
> > -	return 0;
> > +	struct device_node *p2020_cpu;
> > +
> > +	/*
> > +	 * There is no common compatible string for all P2020 boards.
> > +	 * The only common thing is "PowerPC,P2020@0" cpu node.
> > +	 * So check for P2020 board via this cpu node.
> > +	 */
> > +	p2020_cpu = of_find_node_by_path("/cpus/PowerPC,P2020@0");
> > +	if (!p2020_cpu)
> > +		return 0;
> 
> This looks odd. I though all probe were using the compatible, and in 
> fact I have a series in preparation that drops all 
> of_machine_is_compatible() checks in probe functions and do it in the 
> caller instead, after adding a .compatible string in the machine 
> description.
> 
> Is there really no compatible that can be used for all p2020 ?

Really. There is none. I have looked into all available P2020 DTB files
(either externals passed by bootloader or kernel in-tree) and there is
no common compatible string. The only "common" thing is cpu node, how I
implemented it int this patch series.

And same issue is with boards with P101x and P102x DTB files.