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SubjectRe: [RFC][PATCH V4] axi: add AXI bus driver
On Tue, Apr 12, 2011 at 08:52:55PM +0200, Rafał Miłecki wrote:
> Cc: Greg KH <greg@kroah.com>
> Cc: Michael Büsch <mb@bu3sch.de>
> Cc: Larry Finger <Larry.Finger@lwfinger.net>
> Cc: George Kashperko <george@znau.edu.ua>
> Cc: Arend van Spriel <arend@broadcom.com>
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: Russell King <rmk@arm.linux.org.uk>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Andy Botting <andy@andybotting.com>
> Cc: linuxdriverproject <devel@linuxdriverproject.org>
> Cc: linux-kernel@vger.kernel.org <linux-kernel@vger.kernel.org>
> Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
> ---
> Greg: is this what you expected from dynamic allocation and documentation?
>
> Did I miss any other comments about something to change?
>
> V2: Rename to axi
> Use DEFINE_PCI_DEVICE_TABLE in bridge
> Make use of pr_fmt and pr_*
> Store core class
> Rename bridge to not b43 specific
> Replace magic 0x1000 with BCMAI_CORE_SIZE
> Remove some old "ssb" names and defines
> Move BCMAI_ADDR_BASE def
> Add drvdata field
> V3: Fix reloading (kfree issue)
> Add 14e4:0x4331
> Fix non-initialized struct issue
> Drop useless inline functions wrappers for pci core drv
> Proper pr_* usage
> V3.1: Include forgotten changes (pr_* and include related)
> Explain why we dare to implement empty release function
> V4: Add ABI documentation
> Move struct device to wrapper and alloc it dynamically
> checkpatch.pl pointed fixes
> ---
> Documentation/ABI/testing/sysfs-bus-axi | 31 +++
> drivers/Kconfig | 2 +
> drivers/Makefile | 1 +
> drivers/axi/Kconfig | 33 +++
> drivers/axi/Makefile | 7 +
> drivers/axi/TODO | 3 +
> drivers/axi/axi_pci_bridge.c | 33 +++
> drivers/axi/axi_private.h | 37 +++
> drivers/axi/core.c | 51 ++++
> drivers/axi/driver_chipcommon.c | 87 +++++++
> drivers/axi/driver_chipcommon_pmu.c | 134 ++++++++++
> drivers/axi/driver_pci.c | 163 ++++++++++++
> drivers/axi/host_pci.c | 178 +++++++++++++
> drivers/axi/main.c | 271 ++++++++++++++++++++
> drivers/axi/scan.c | 392 +++++++++++++++++++++++++++++
> drivers/axi/scan.h | 56 ++++
> include/linux/axi/axi.h | 227 +++++++++++++++++
> include/linux/axi/axi_driver_chipcommon.h | 308 ++++++++++++++++++++++
> include/linux/axi/axi_driver_pci.h | 89 +++++++
> include/linux/axi/axi_regs.h | 34 +++
> include/linux/mod_devicetable.h | 17 ++
> scripts/mod/file2alias.c | 21 ++
> 22 files changed, 2175 insertions(+), 0 deletions(-)
> create mode 100644 Documentation/ABI/testing/sysfs-bus-axi
> create mode 100644 drivers/axi/Kconfig
> create mode 100644 drivers/axi/Makefile
> create mode 100644 drivers/axi/TODO
> create mode 100644 drivers/axi/axi_pci_bridge.c
> create mode 100644 drivers/axi/axi_private.h
> create mode 100644 drivers/axi/core.c
> create mode 100644 drivers/axi/driver_chipcommon.c
> create mode 100644 drivers/axi/driver_chipcommon_pmu.c
> create mode 100644 drivers/axi/driver_pci.c
> create mode 100644 drivers/axi/host_pci.c
> create mode 100644 drivers/axi/main.c
> create mode 100644 drivers/axi/scan.c
> create mode 100644 drivers/axi/scan.h
> create mode 100644 include/linux/axi/axi.h
> create mode 100644 include/linux/axi/axi_driver_chipcommon.h
> create mode 100644 include/linux/axi/axi_driver_pci.h
> create mode 100644 include/linux/axi/axi_regs.h
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-axi b/Documentation/ABI/testing/sysfs-bus-axi
> new file mode 100644
> index 0000000..6223612
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-axi
> @@ -0,0 +1,31 @@
> +What: /sys/bus/axi/devices/.../class
> +Date: April 2011
> +KernelVersion: 2.6.40
> +Contact: Rafał Miłecki <zajec5@gmail.com>
> +Description:
> + Each AXI core is identified by few fields, including class it
> + belongs to. See include/linux/axi/axi.h for possible values.
> +
> +What: /sys/bus/axi/devices/.../manuf
> +Date: April 2011
> +KernelVersion: 2.6.40
> +Contact: Rafał Miłecki <zajec5@gmail.com>
> +Description:
> + Each AXI core has it's manufacturer id. See
> + include/linux/axi/axi.h for possible values.
> +
> +What: /sys/bus/axi/devices/.../rev
> +Date: April 2011
> +KernelVersion: 2.6.40
> +Contact: Rafał Miłecki <zajec5@gmail.com>
> +Description:
> + AXI cores of the same type can still slightly differ depending
> + on their revision. Use it for detailed programming.
> +
> +What: /sys/bus/axi/devices/.../id
> +Date: April 2011
> +KernelVersion: 2.6.40
> +Contact: Rafał Miłecki <zajec5@gmail.com>
> +Description:
> + There are a few types of AXI cores, they can be identified by
> + id field.
> diff --git a/drivers/Kconfig b/drivers/Kconfig
> index 177c7d1..1244e8c 100644
> --- a/drivers/Kconfig
> +++ b/drivers/Kconfig
> @@ -68,6 +68,8 @@ source "drivers/watchdog/Kconfig"
>
> source "drivers/ssb/Kconfig"
>
> +source "drivers/axi/Kconfig"
> +
> source "drivers/mfd/Kconfig"
>
> source "drivers/regulator/Kconfig"
> diff --git a/drivers/Makefile b/drivers/Makefile
> index 3f135b6..6e1979b 100644
> --- a/drivers/Makefile
> +++ b/drivers/Makefile
> @@ -110,6 +110,7 @@ obj-$(CONFIG_HID) += hid/
> obj-$(CONFIG_PPC_PS3) += ps3/
> obj-$(CONFIG_OF) += of/
> obj-$(CONFIG_SSB) += ssb/
> +obj-$(CONFIG_AXI) += axi/
> obj-$(CONFIG_VHOST_NET) += vhost/
> obj-$(CONFIG_VLYNQ) += vlynq/
> obj-$(CONFIG_STAGING) += staging/
> diff --git a/drivers/axi/Kconfig b/drivers/axi/Kconfig
> new file mode 100644
> index 0000000..6221af0
> --- /dev/null
> +++ b/drivers/axi/Kconfig
> @@ -0,0 +1,33 @@
> +config AXI_POSSIBLE
> + bool
> + depends on HAS_IOMEM && HAS_DMA
> + default y
> +
> +menu "AMBA AXI"
> + depends on AXI_POSSIBLE
> +
> +config AXI
> + tristate "AXI support"
> + depends on AXI_POSSIBLE
> + help
> + Bus driver for one of the Advanced Microcontroller Bus Architecture
> + interfaces: Advanced eXtensible Interface.
> +
> +config AXI_HOST_PCI_POSSIBLE
> + bool
> + depends on AXI && PCI = y
> + default y
> +
> +config AXI_HOST_PCI
> + bool "Support for AXI on PCI-host bus"
> + depends on AXI_HOST_PCI_POSSIBLE
> +
> +config AXI_DEBUG
> + bool "AXI debugging"
> + depends on AXI
> + help
> + This turns on additional debugging messages.
> +
> + If unsure, say N
> +
> +endmenu
> diff --git a/drivers/axi/Makefile b/drivers/axi/Makefile
> new file mode 100644
> index 0000000..50d6797
> --- /dev/null
> +++ b/drivers/axi/Makefile
> @@ -0,0 +1,7 @@
> +axi-y += main.o scan.o core.o
> +axi-y += driver_chipcommon.o driver_chipcommon_pmu.o
> +axi-y += driver_pci.o
> +axi-$(CONFIG_AXI_HOST_PCI) += host_pci.o axi_pci_bridge.o
> +obj-$(CONFIG_AXI) += axi.o
> +
> +ccflags-$(CONFIG_AXI_DEBUG) := -DDEBUG
> diff --git a/drivers/axi/TODO b/drivers/axi/TODO
> new file mode 100644
> index 0000000..5190336
> --- /dev/null
> +++ b/drivers/axi/TODO
> @@ -0,0 +1,3 @@
> +- Interrupts
> +- Defines for PCI core driver
> +- Convert axi_bus->cores into linked list
> diff --git a/drivers/axi/axi_pci_bridge.c b/drivers/axi/axi_pci_bridge.c
> new file mode 100644
> index 0000000..17e882c
> --- /dev/null
> +++ b/drivers/axi/axi_pci_bridge.c
> @@ -0,0 +1,33 @@
> +/*
> + * AXI PCI bridge module
> + *
> + * Licensed under the GNU/GPL. See COPYING for details.
> + */
> +
> +#include "axi_private.h"
> +
> +#include <linux/axi/axi.h>
> +#include <linux/pci.h>
> +
> +static DEFINE_PCI_DEVICE_TABLE(axi_pci_bridge_tbl) = {
> + { PCI_DEVICE(PCI_VENDOR_ID_BROADCOM, 0x4331) },
> + { PCI_DEVICE(PCI_VENDOR_ID_BROADCOM, 0x4353) },
> + { PCI_DEVICE(PCI_VENDOR_ID_BROADCOM, 0x4727) },
> + { 0, },
> +};
> +MODULE_DEVICE_TABLE(pci, axi_pci_bridge_tbl);
> +
> +static struct pci_driver axi_pci_bridge_driver = {
> + .name = "axi-pci-bridge",
> + .id_table = axi_pci_bridge_tbl,
> +};
> +
> +int __init axi_pci_bridge_init(void)
> +{
> + return axi_host_pci_register(&axi_pci_bridge_driver);
> +}
> +
> +void __exit axi_pci_bridge_exit(void)
> +{
> + axi_host_pci_unregister(&axi_pci_bridge_driver);
> +}

You register a pci driver that does nothing? That's not right, you need
to then base your axi bus off of that pci device, so it is hooked up
correctly in the /sys/devices/ tree. Otherwise you are somewhere up in
the virtual location for your axi bus, right?

> +bool axi_core_is_enabled(struct axi_device *core)
> +{
> + if ((axi_aread32(core, AXI_IOCTL) & (AXI_IOCTL_CLK | AXI_IOCTL_FGC))
> + != AXI_IOCTL_CLK)
> + return false;
> + if (axi_aread32(core, AXI_RESET_CTL) & AXI_RESET_CTL_RESET)
> + return false;
> + return true;
> +}
> +EXPORT_SYMBOL(axi_core_is_enabled);

EXPORT_SYMBOL_GPL()?

What module uses this? And why would it care?

> +EXPORT_SYMBOL(axi_core_enable);

EXPORT_SYMBOL_GPL()?

Same goes for your other exports, just want you to be sure here.

> +u32 xaxi_chipco_gpio_control(struct axi_drv_cc *cc, u32 mask, u32 value)
> +{
> + return axi_cc_write32_masked(cc, AXI_CC_GPIOCTL, mask, value);
> +}
> +EXPORT_SYMBOL(xaxi_chipco_gpio_control);

"xaxi"? Shouldn't that be consistant with the other exports and start
with "axi"?

> +static u8 axi_host_pci_read8(struct axi_device *core, u16 offset)
> +{
> + if (unlikely(core->bus->mapped_core != core))

Are you sure about the use of unlikely in this, and other functions?
The compiler almost always does a better job than we do for these types
of calls, just let it do it's job.

> + axi_host_pci_switch_core(core);
> + return ioread8(core->bus->mmio + offset);

I think because of that unlikely, you just slowed down all pci devices,
right? That's not very nice :)


thanks,

greg k-h
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