Revision 118c9a45fdacc6fe57910fa1d048e2d5bbc193f4 authored by Linus Torvalds on 02 April 2013, 15:35:03 UTC, committed by Linus Torvalds on 02 April 2013, 15:35:03 UTC
Pull ARM SoC bug fixes from Arnd Bergmann: "After a quiet set of fixes for 3.9-rc4, a lot of people woke up and sent urgent fixes for 3.9. I pushed back on a number of them that got deferred to 3.10, but these are the ones that seemed important. Regression in 3.9: - Multiple regressions in OMAP2+ clock cleanup - SH-Mobile frame buffer bug fix that merged here because of maintainer MIA - ux500 prcmu changes broke DT booting - MMCI duplicated regulator setup on ux500 - New ux500 clock driver broke ethernet on snowball - Local interrupt driver for mvebu broke ethernet - MVEBU GPIO driver did not get set up right on Orion DT - incorrect interrupt number on Orion crypto for DT Long-standing bugs, including candidates for stable: - Kirkwood MMC needs to disable invalid card detect pins - MV SDIO pinmux was wrong on Mirabox - GoFlex Net board file needs to set NAND chip delay - MSM timer restart race - ep93xx early debug code broke in 3.7 - i.MX CPU hotplug race - Incorrect clock setup for OMAP1 USB - Workaround for bad clock setup by some old OMAP4 boot loaders - Static I/O mappings on cns3xxx since 3.2" * tag 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: ARM: cns3xxx: fix mapping of private memory region arm: mvebu: Fix pinctrl for Armada 370 Mirabox SDIO port. arm: orion5x: correct IRQ used in dtsi for mv_cesa arm: orion5x: fix orion5x.dtsi gpio parameters ARM: Kirkwood: fix unused mvsdio gpio pins arm: mvebu: Use local interrupt only for the timer 0 ARM: kirkwood: Fix chip-delay for GoFlex Net ARM: ux500: Enable the clock controlling Ethernet on Snowball ARM: ux500: Stop passing ios_handler() as an MMCI power controlling call-back ARM: ux500: Apply the TCPM and TCDM locations and sizes to dbx5x0 DT fbdev: sh_mobile_lcdc: fixup B side hsync adjust settings ARM: OMAP: clocks: Delay clk inits atleast until slab is initialized ARM: imx: fix sync issue between imx_cpu_die and imx_cpu_kill ARM: msm: Stop counting before reprogramming clockevent ARM: ep93xx: Fix wait for UART FIFO to be empty ARM: OMAP4: PM: fix PM regression introduced by recent clock cleanup ARM: OMAP3: hwmod data: keep MIDLEMODE in force-standby for musb ARM: OMAP4: clock data: lock USB DPLL on boot ARM: OMAP1: fix USB host on 1710
eisa.txt
EISA bus support (Marc Zyngier <maz@wild-wind.fr.eu.org>)
This document groups random notes about porting EISA drivers to the
new EISA/sysfs API.
Starting from version 2.5.59, the EISA bus is almost given the same
status as other much more mainstream busses such as PCI or USB. This
has been possible through sysfs, which defines a nice enough set of
abstractions to manage busses, devices and drivers.
Although the new API is quite simple to use, converting existing
drivers to the new infrastructure is not an easy task (mostly because
detection code is generally also used to probe ISA cards). Moreover,
most EISA drivers are among the oldest Linux drivers so, as you can
imagine, some dust has settled here over the years.
The EISA infrastructure is made up of three parts :
- The bus code implements most of the generic code. It is shared
among all the architectures that the EISA code runs on. It
implements bus probing (detecting EISA cards available on the bus),
allocates I/O resources, allows fancy naming through sysfs, and
offers interfaces for driver to register.
- The bus root driver implements the glue between the bus hardware
and the generic bus code. It is responsible for discovering the
device implementing the bus, and setting it up to be latter probed
by the bus code. This can go from something as simple as reserving
an I/O region on x86, to the rather more complex, like the hppa
EISA code. This is the part to implement in order to have EISA
running on an "new" platform.
- The driver offers the bus a list of devices that it manages, and
implements the necessary callbacks to probe and release devices
whenever told to.
Every function/structure below lives in <linux/eisa.h>, which depends
heavily on <linux/device.h>.
** Bus root driver :
int eisa_root_register (struct eisa_root_device *root);
The eisa_root_register function is used to declare a device as the
root of an EISA bus. The eisa_root_device structure holds a reference
to this device, as well as some parameters for probing purposes.
struct eisa_root_device {
struct device *dev; /* Pointer to bridge device */
struct resource *res;
unsigned long bus_base_addr;
int slots; /* Max slot number */
int force_probe; /* Probe even when no slot 0 */
u64 dma_mask; /* from bridge device */
int bus_nr; /* Set by eisa_root_register */
struct resource eisa_root_res; /* ditto */
};
node : used for eisa_root_register internal purpose
dev : pointer to the root device
res : root device I/O resource
bus_base_addr : slot 0 address on this bus
slots : max slot number to probe
force_probe : Probe even when slot 0 is empty (no EISA mainboard)
dma_mask : Default DMA mask. Usually the bridge device dma_mask.
bus_nr : unique bus id, set by eisa_root_register
** Driver :
int eisa_driver_register (struct eisa_driver *edrv);
void eisa_driver_unregister (struct eisa_driver *edrv);
Clear enough ?
struct eisa_device_id {
char sig[EISA_SIG_LEN];
unsigned long driver_data;
};
struct eisa_driver {
const struct eisa_device_id *id_table;
struct device_driver driver;
};
id_table : an array of NULL terminated EISA id strings,
followed by an empty string. Each string can
optionally be paired with a driver-dependent value
(driver_data).
driver : a generic driver, such as described in
Documentation/driver-model/driver.txt. Only .name,
.probe and .remove members are mandatory.
An example is the 3c59x driver :
static struct eisa_device_id vortex_eisa_ids[] = {
{ "TCM5920", EISA_3C592_OFFSET },
{ "TCM5970", EISA_3C597_OFFSET },
{ "" }
};
static struct eisa_driver vortex_eisa_driver = {
.id_table = vortex_eisa_ids,
.driver = {
.name = "3c59x",
.probe = vortex_eisa_probe,
.remove = vortex_eisa_remove
}
};
** Device :
The sysfs framework calls .probe and .remove functions upon device
discovery and removal (note that the .remove function is only called
when driver is built as a module).
Both functions are passed a pointer to a 'struct device', which is
encapsulated in a 'struct eisa_device' described as follows :
struct eisa_device {
struct eisa_device_id id;
int slot;
int state;
unsigned long base_addr;
struct resource res[EISA_MAX_RESOURCES];
u64 dma_mask;
struct device dev; /* generic device */
};
id : EISA id, as read from device. id.driver_data is set from the
matching driver EISA id.
slot : slot number which the device was detected on
state : set of flags indicating the state of the device. Current
flags are EISA_CONFIG_ENABLED and EISA_CONFIG_FORCED.
res : set of four 256 bytes I/O regions allocated to this device
dma_mask: DMA mask set from the parent device.
dev : generic device (see Documentation/driver-model/device.txt)
You can get the 'struct eisa_device' from 'struct device' using the
'to_eisa_device' macro.
** Misc stuff :
void eisa_set_drvdata (struct eisa_device *edev, void *data);
Stores data into the device's driver_data area.
void *eisa_get_drvdata (struct eisa_device *edev):
Gets the pointer previously stored into the device's driver_data area.
int eisa_get_region_index (void *addr);
Returns the region number (0 <= x < EISA_MAX_RESOURCES) of a given
address.
** Kernel parameters :
eisa_bus.enable_dev :
A comma-separated list of slots to be enabled, even if the firmware
set the card as disabled. The driver must be able to properly
initialize the device in such conditions.
eisa_bus.disable_dev :
A comma-separated list of slots to be enabled, even if the firmware
set the card as enabled. The driver won't be called to handle this
device.
virtual_root.force_probe :
Force the probing code to probe EISA slots even when it cannot find an
EISA compliant mainboard (nothing appears on slot 0). Defaults to 0
(don't force), and set to 1 (force probing) when either
CONFIG_ALPHA_JENSEN or CONFIG_EISA_VLB_PRIMING are set.
** Random notes :
Converting an EISA driver to the new API mostly involves *deleting*
code (since probing is now in the core EISA code). Unfortunately, most
drivers share their probing routine between ISA, and EISA. Special
care must be taken when ripping out the EISA code, so other busses
won't suffer from these surgical strikes...
You *must not* expect any EISA device to be detected when returning
from eisa_driver_register, since the chances are that the bus has not
yet been probed. In fact, that's what happens most of the time (the
bus root driver usually kicks in rather late in the boot process).
Unfortunately, most drivers are doing the probing by themselves, and
expect to have explored the whole machine when they exit their probe
routine.
For example, switching your favorite EISA SCSI card to the "hotplug"
model is "the right thing"(tm).
** Thanks :
I'd like to thank the following people for their help :
- Xavier Benigni for lending me a wonderful Alpha Jensen,
- James Bottomley, Jeff Garzik for getting this stuff into the kernel,
- Andries Brouwer for contributing numerous EISA ids,
- Catrin Jones for coping with far too many machines at home.
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