Re: [PATCH 1/6] ARM: cygnus: Initial support for Broadcom Cygnus SoC
From: Scott Branden
Date: Wed Oct 08 2014 - 08:27:47 EST
Thanks for the review - comments inline.
On 14-10-08 12:54 AM, Arnd Bergmann wrote:
On Tuesday 07 October 2014 22:27:00 Scott Branden wrote:
From: Jonathan Richardson <jonathar@xxxxxxxxxxxx>
Adds initial support for the Cygnus SoC based on Broadcomâs iProc series.
Reviewed-by: Ray Jui <rjui@xxxxxxxxxxxx>
Reviewed-by: Desmond Liu <desmondl@xxxxxxxxxxxx>
Reviewed-by: JD (Jiandong) Zheng <jdzheng@xxxxxxxxxxxx>
Tested-by: Jonathan Richardson <jonathar@xxxxxxxxxxxx>
Signed-off-by: Scott Branden <sbranden@xxxxxxxxxxxx>
---
arch/arm/mach-bcm/Kconfig | 31 ++++++++
arch/arm/mach-bcm/Makefile | 3 +
arch/arm/mach-bcm/bcm_cygnus.c | 166 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 200 insertions(+)
create mode 100644 arch/arm/mach-bcm/bcm_cygnus.c
diff --git a/arch/arm/mach-bcm/Kconfig b/arch/arm/mach-bcm/Kconfig
index fc93800..2dd3f78 100644
--- a/arch/arm/mach-bcm/Kconfig
+++ b/arch/arm/mach-bcm/Kconfig
@@ -5,6 +5,37 @@ menuconfig ARCH_BCM
if ARCH_BCM
+config ARCH_BCM_IPROC
+ bool "Broadcom ARMv7 iProc boards" if ARCH_MULTI_V7
+ select ARM_GIC
+ select CACHE_L2X0
+ select HAVE_ARM_TWD if LOCAL_TIMERS
+ select HAVE_CLK
+ select CLKSRC_OF
+ select CLKSRC_MMIO
+ select GENERIC_CLOCKEVENTS
+ select ARM_GLOBAL_TIMER
+ select ARCH_REQUIRE_GPIOLIB
+ select ARM_AMBA
+ select PINCTRL
+ select DEBUG_UART_8250
A lot of these are implied by ARCH_MULTI_V7, just drop them here.
Some others like DEBUG_UART_8250 should remain user-selectable, if
the platform works without them.
Will review. It looks like DEBUG_UART_8250 actually has to move to
Kconfig.debug as that is where everyone else selects it.
+ help
+ This enables support for systems based on Broadcom IPROC architected SoCs.
+ The IPROC complex contains one or more ARM CPUs along with common
+ core periperals. Application specific SoCs are created by adding a
+ uArchitecture containing peripherals outside of the IPROC complex.
+ Currently supported SoCs are Cygnus.
+
+menu "iProc SoC based Machine types"
+ depends on ARCH_BCM_IPROC
+
+ config ARCH_BCM_CYGNUS
+ bool "Support Broadcom Cygnus board"
+ select USB_ARCH_HAS_EHCI if USB_SUPPORT
+ help
+ Support for Broadcom Cygnus SoC.
+endmenu
I don't think you need per-board config options. The main option
above should be enough.
This is not a per-board config option. This is actually a per-SoC
uArchtecture selection. More major uArchectures will be added to the
IPROC. Will Change comment to "Support Broadcom Cygnus SoC"
+
+#define CRMU_MAIL_BOX1 0x03024028
+#define CRMU_SOFT_RESET_CMD 0xFFFFFFFF
Never hardcode physical register locations in source. This should come
from DT, and get moved into a regular 'reset' device driver.
You probably want to use drivers/power/reset/syscon-reboot.c
OK, thanks for advice on where to put reset device driver. Will
investigate.
+/* CRU_RESET register */
+static void * __iomem crmu_mail_box1_reg;
+
+#ifdef CONFIG_NEON
+
+#define CRU_BASE 0x1800e000
+#define CRU_SIZE 0x34
+#define CRU_CONTROL_OFFSET 0x0
+#define CRU_PWRDWN_EN_OFFSET 0x4
+#define CRU_PWRDWN_STATUS_OFFSET 0x8
+#define CRU_NEON0_HW_RESET 6
+#define CRU_CLAMP_ON_NEON0 20
+#define CRU_PWRONIN_NEON0 21
+#define CRU_PWRONOUT_NEON0 21
+#define CRU_PWROKIN_NEON0 22
+#define CRU_PWROKOUT_NEON0 22
+#define CRU_STATUS_DELAY_NS 500
+#define CRU_MAX_RETRY_COUNT 10
+#define CRU_RETRY_INTVL_US 1
+
+/* Power up the NEON/VFPv3 block. */
+static void bcm_cygnus_powerup_neon(void)
+{
+ void * __iomem cru_base = ioremap(CRU_BASE, CRU_SIZE);
+ u32 reg, i;
Same thing here: this should really use the device node for CRU.
Can you describe what the CRU is? Is this specific to NEON or is
it some general-purpose power management unit?
It's a central resource unit with a lot of random registers to perform
various operations. To reduce confusion I'll probably move this out of
the kernel init and into the bootloader. This will simplify the kernel
init.
+static void __init bcm_cygnus_init(void)
+{
+ of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
+
+ l2x0_of_init(0, ~0UL);
The l2x0_of_init can be removed now, just move the arguments into the
respective fields of the machine descriptor.
Yes, thanks for pointing this out.
+ crmu_mail_box1_reg = ioremap(CRMU_MAIL_BOX1, SZ_4);
+ WARN_ON(!crmu_mail_box1_reg);
+
+#ifdef CONFIG_NEON
+ bcm_cygnus_powerup_neon();
+#endif
+}
In general, try to avoid #ifdef, use
if (IS_ENABLED(CONFIG_NEON))
bcm_cygnus_powerup_neon();
instead.
+
+static const char const *bcm_cygnus_dt_compat[] = {
+ "brcm,cygnus",
+ NULL,
+};
+
+DT_MACHINE_START(BCM_CYGNUS_DT, "Broadcom Cygnus SoC")
+ .init_machine = bcm_cygnus_init,
+ .map_io = debug_ll_io_init,
+ .dt_compat = bcm_cygnus_dt_compat,
+ .restart = bcm_cygnus_restart
+MACHINE_END
The map_io pointer is unnecessary, and the restart pointer should get
set by the reset driver. I hope we can find a way to avoid the
bcm_cygnus_init callback as well.
bcm_cygnus_init callback can be removed by moving initialization to
bootloader.
Arnd
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