> Subject: Re: [PATCH] ARM: Add support for Realtek SOC > > On Thu, Sep 5, 2019 at 7:48 AM <jamestai....@gmail.com> wrote: > > > > From: "james.tai" <james....@realtek.com> > > > > This patch adds the basic machine file for the Realtek RTD16XX > > platform. > > > > Signed-off-by: james.tai <james....@realtek.com> > > Hi James, > > Thanks a lot for your submission! I'm glad to see interest in upstream support > for this SoC family. I have a few small comments on details, mostly where I > would either like to see an explanation in the patch description, or things > that > looks like they can be left out from the patch. > Thanks for your reply.
> > index 33b00579beff..c7c9a3662eb7 100644 > > --- a/arch/arm/Kconfig > > +++ b/arch/arm/Kconfig > > @@ -836,6 +836,8 @@ source "arch/arm/mach-zx/Kconfig" > > > > source "arch/arm/mach-zynq/Kconfig" > > > > +source "arch/arm/mach-realtek/Kconfig" > > + > > diff --git a/arch/arm/mach-realtek/Kconfig > b/arch/arm/mach-realtek/Kconfig > > @@ -225,6 +226,7 @@ machine-$(CONFIG_ARCH_VT8500) > += vt8500 > > machine-$(CONFIG_ARCH_W90X900) += w90x900 > > machine-$(CONFIG_ARCH_ZX) += zx > > machine-$(CONFIG_ARCH_ZYNQ) += zynq > > +machine-$(CONFIG_ARCH_REALTEK) += realtek > > machine-$(CONFIG_PLAT_SPEAR) += spear > > > > # Platform directory name. This list is sorted alphanumerically > > Please keep these lists in alphabetical order. > I will keep these lists in alphabetical order in new version patch. > > # ARMv7-M architecture > > config ARCH_EFM32 > > bool "Energy Micro efm32" > > diff --git a/arch/arm/Makefile b/arch/arm/Makefile index > > c3624ca6c0bc..1f0926449d47 100644 > > --- a/arch/arm/Makefile > > +++ b/arch/arm/Makefile > > @@ -148,6 +148,7 @@ endif > > textofs-$(CONFIG_ARCH_MSM8X60) := 0x00208000 > > textofs-$(CONFIG_ARCH_MSM8960) := 0x00208000 > > textofs-$(CONFIG_ARCH_MESON) := 0x00208000 > > +textofs-$(CONFIG_ARCH_REALTEK) := 0x00208000 > > textofs-$(CONFIG_ARCH_AXXIA) := 0x00308000 > > Can you explain why this is needed for your platform? > We need to reserve memory (0x00000000 ~ 0x001B0000) for rom and boot code. > > # Machine directory name. This list is sorted alphanumerically new > > file mode 100644 index 000000000000..a8269964dbdb > > --- /dev/null > > +++ b/arch/arm/mach-realtek/Kconfig > > @@ -0,0 +1,32 @@ > > +# SPDX-License-Identifier: GPL-2.0-only menuconfig ARCH_REALTEK > > + bool "Realtek SoCs" > > Please add "depends on ARCH_MULTI_V7" to avoid compile time issues when > selecting it on an earlier architecture. > I will add "depends on ARCH_MULTI_V7" in new version patch. > > + select ARM_GLOBAL_TIMER > > + select CLKDEV_LOOKUP > > + select HAVE_SMP > > + select HAVE_MACH_CLKDEV > > + select GENERIC_CLOCKEVENTS > > + select HAVE_SCHED_CLOCK > > + select ARCH_HAS_CPUFREQ > > + select CLKSRC_OF > > + select ARCH_REQUIRE_GPIOLIB > > + select GENERIC_IRQ_CHIP > > + select IRQ_DOMAIN > > + select PINCTRL > > + select COMMON_CLK > > + select ARCH_HAS_BARRIERS > > + select SPARSE_IRQ > > + select PM_OPP > > + select ARM_HAS_SG_CHAIN > > + select ARM_PATCH_PHYS_VIRT > > + select AUTO_ZRELADDR > > + select MIGHT_HAVE_PCI > > + select MULTI_IRQ_HANDLER > > + select PCI_DOMAINS if PCI > > + select USE_OF > > Almost all of the symbols above are implied by > ARCH_MULTI_V7 and should not be selected separately. > OK, I understand. > > +config ARCH_RTD16XX > > + bool "Enable support for RTD1619" > > + depends on ARCH_REALTEK > > + select ARM_GIC_V3 > > + select ARM_PSCI > > As I understand, this chip uses a Cortex-A55. What is the reason for adding > support only to the 32-bit ARM architecture rather than 64-bit? The RTD16XX platform also support the 64-bit ARM architecture. I will add the 64-bit ARM architecture in new version patch. > Most 64-bit SoCs are only supported with arch/arm64, but generally speaking > that is not a requirement. My rule of thumb is that on systems with 1GB of > RAM or more, one would want to run a 64-bit kernel, while systems with less > than that are better off with a 32-bit one, but that is clearly not the only > reason > for picking one over the other. > Support 32-bit ARM architecture is for application compatibility. > > + > > +static int rtk_boot_secondary(unsigned int cpu, struct task_struct > > +*idle) { > > + unsigned long entry_pa = __pa_symbol(secondary_startup); > > + > > + writel_relaxed(entry_pa | (cpu << CPUID), cpu_release_virt); > > + > > + arch_send_wakeup_ipi_mask(cpumask_of(cpu)); > > + > > + return 0; > > +} > > It's very unusual to see custom smp operations on an ARMv8 system, as we > normally use PSCI here. Can you explain what is going on here? Are you able to > use a boot wrapper that implements these in psci instead? > The smp operations is porting form other Realtek platform. Currently, The RTD16XX platform can use the PSCI method. I will add PSCI method in new version patch. > > + > > +#include "platsmp.h" > > + > > +#define RBUS_BASE_PHYS (0x98000000) > > +#define RBUS_BASE_VIRT (0xfe000000) > > +#define RBUS_BASE_SIZE (0x00100000) > > + > > +static struct map_desc rtk_io_desc[] __initdata = { > > + { > > + .virtual = (unsigned long) IOMEM(RBUS_BASE_VIRT), > > + .pfn = __phys_to_pfn(RBUS_BASE_PHYS), > > + .length = RBUS_BASE_SIZE, > > + .type = MT_DEVICE, > > + }, > > +}; > > This needs a comment: Why do you require a static mapping for > "RBUS_BASE_PHYS"? Normally device drivers should just use > ioremap() for mapping whichever registers they want to access. > The static mapping is for old Realtek devices driver. I will 'use ioremap()' to replace with static mapping. > > +static void __init rtk_dt_init(void) > > +{ > > + of_platform_populate(NULL, of_default_bus_match_table, NULL, > > +NULL); } > > This should be taken care of by the > of_platform_default_populate_init() and can be dropped. > I will remove rtk_dt_init() in new version patch. > > +static void __init rtk_timer_init(void) { #ifdef CONFIG_COMMON_CLK > > + of_clk_init(NULL); > > +#endif > > COMMON_CLK is implied by ARCH_MULTI_V7, so the #ifdef can be dropped. > OK, I understand. > > + timer_probe(); > > + tick_setup_hrtimer_broadcast(); } > > What do you need tick_setup_hrtimer_broadcast() for? I don't see any other > platform calling this. > I want to initialize the HR timer. > > +bool __init rtk_smp_init_ops(void) > > +{ > > + smp_set_ops(smp_ops(rtk_smp_ops)); > > + > > + return true; > > +} > > I think this can also be dropped, as you set the smp_ops in the machine > descriptor. > OK, I understand. > Arnd > > ------Please consider the environment before printing this e-mail.