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. > 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. > # 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? > # 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. > + 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. > +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? 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. > + > +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? > + > +#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. > +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. > +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. > + timer_probe(); > + tick_setup_hrtimer_broadcast(); > +} What do you need tick_setup_hrtimer_broadcast() for? I don't see any other platform calling this. > +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. Arnd