The local array feature[] is in the stack. We can see the warning
when we enable the CONFIG_DMA_API_DEBUG:
----------------------------------------------------------
WARNING: at lib/dma-debug.c:950 check_for_stack+0xac/0xf8()
gpmi-nand 112000.gpmi-nand: DMA-API: device driver maps memory fromstack [addr=dc05be34]
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.10.17-16851-g2414a73 #1324
[<80014cbc>] (unwind_backtrace+0x0/0x138) from [<8001251c>] (show_stack+0x10/0x14)
[<8001251c>] (show_stack+0x10/0x14) from [<8002699c>] (warn_slowpath_common+0x4c/0x68)
[<8002699c>] (warn_slowpath_common+0x4c/0x68) from [<80026a4c>] (warn_slowpath_fmt+0x30/0x40)
[<80026a4c>] (warn_slowpath_fmt+0x30/0x40) from [<8028e2f8>] (check_for_stack+0xac/0xf8)
[<8028e2f8>] (check_for_stack+0xac/0xf8) from [<8028e438>] (debug_dma_map_sg+0xf4/0x188)
[<8028e438>] (debug_dma_map_sg+0xf4/0x188) from [<803968d0>] (prepare_data_dma+0xb8/0x1a8)
[<803968d0>] (prepare_data_dma+0xb8/0x1a8) from [<80397b20>] (gpmi_send_data+0x84/0xfc)
[<80397b20>] (gpmi_send_data+0x84/0xfc) from [<8038c2b4>] (nand_onfi_set_features+0x50/0x74)
[<8038c2b4>] (nand_onfi_set_features+0x50/0x74) from [<80397198>] (gpmi_extra_init+0x90/0x170)
[<80397198>] (gpmi_extra_init+0x90/0x170) from [<8039520c>] (gpmi_nand_probe+0x2f8/0xb3c)
[<8039520c>] (gpmi_nand_probe+0x2f8/0xb3c) from [<8031b974>] (platform_drv_probe+0x18/0x1c)
----------------------------------------------------------

The patch uses the kzalloc to allocate the buffer, and free it when
we do not use it anymore.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

The Armada BCH configuration in this driver uses one of the two
following ECC schemes:

 16-bit correction per 2048 bytes
 16-bit correction per 1024 bytes

These are sufficient for mapping to the 4-bit per 512-bytes and 8-bit
per 512-bytes (respectively) minimum correctability requirements of many
common NAND.

The current code only checks for the required strength (4-bit or 8-bit)
without checking the ECC step size that is associated with that strength
(and simply assumes it is 512). While that is often a safe assumption to
make, let's make it explicit, since we have that information.
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>

This commit extends the ECC correctable error detection to include
ECC BCH errors. The number of BCH correctable errors can be any up to 16,
and the actual value is exposed in the NDSR register.

Therefore, we change some symbol names to refer to correctable or
uncorrectable (instead of single-bit or double-bit as it was in the
Hamming case) and while at it, cleanup the detection code slightly.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This commit adds write support for large pages (4 KiB, 8 KiB).
Such support is implemented by issuing a multiple command sequence,
transfering a set of 2 KiB chunks per transaction.

The splitted command sequence requires to send the SEQIN command
independently of the PAGEPROG command and therefore it's set as
an execution command.

Since PAGEPROG enables ECC, each 2 KiB chunk of data is written
together with ECC code at a controller-fixed location within
the flash page.

Currently, only devices with a 4 KiB page size has been tested.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

As preparation work to fully support large pages, this commit adds
the initial infrastructure to support splitted (aka chunked) I/O
operation. This commit adds support for read, and follow-up patches
will add write support.

When a read (aka READ0) command is issued, the driver loops issuing
the same command until all the requested data is transfered, changing
the 'extended' command field as needed.

For instance, if the driver is required to read a 4 KiB page, using a
chunk size of 2 KiB, the transaction is splitted in:
1. Monolithic read, first 2 KiB page chunk is read
2. Last naked read, second and last 2KiB page chunk is read

If ECC is enabled it is calculated on each chunk transfered and added
at a controller-fixed location after the data chunk that must be
spare area.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

In preparation to support multiple (aka chunked, aka splitted)
page I/O, this commit adds 'data_buff_pos' and 'oob_buff_pos' fields
to keep track of where the next read (or write) should be done.

This will allow multiple calls to handle_data_pio() to continue
the read (or write) operation.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This commit adds support page programming with a non-zero "column"
address setting. This is important to support OOB writing, through
command sequences such as:

  cmdfunc(mtd, NAND_CMD_SEQIN, mtd->writesize, ofs);
  write_buf(mtd, oob_buf, 6);
  cmdfunc(mtd, NAND_CMD_PAGEPROG, -1, -1);
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

To allow future support of multiple page reading/writing, move the data
buffer clean out of prepare_set_command().

This is done to prevent the data buffer from being cleaned on every command
preparation, when a multiple command sequence is implemented to read/write
pages larger than the FIFO size (2 KiB).
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This commit splits the prepare_command_pool() function into two
stages: prepare_start_command() / prepare_set_command().

This is a preparation patch without any functionality changes,
and is meant to allow support for multiple page reading/writing
operations.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

READ0 and READOOB command preparation has a falltrough to SEQIN
case, where the command address is specified.
This is certainly confusing and makes the code less readable with
no added value. Let's remove it.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Let's simplify the code by first introducing a helper function
to set the page address, as done by the READ0, READOOB and SEQIN
commands.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Command buffer #3 is not properly cleared and it keeps the last
set value. Fix this by clearing when a command is setup.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This commit adds the BCH ECC support available in NFCv2 controller.
Depending on the detected required strength the respective ECC layout
is selected.

This commit adds an empty ECC layout, since support to access large
pages is first required. Once that support is added, a proper ECC
layout will be added as well.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Add support for flash-based bad block table using Marvell's
custom in-flash bad block table layout. The support is enabled
a 'flash_bbt' platform data or device tree parameter.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

In pxa3xx_nand_sensing() instead of simply using info->is_ready
after issuing a command, the correct way of checking is to wait
for the device to be ready through the chip's waitfunc().
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

The expected behavior of the waitfunc() NAND chip call is to wait
for the device to be READY (this is a standard chip line).
However, the current implementation does almost nothing, which opens
the possibility of issuing a command to a non-ready device.

Fix this by adding a new completion to wait for the ready event to arrive.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Add a comment clarifying the use of pxa3xx_set_datasize() which is only
applicable on data read/write commands (i.e. commands with a data cycle,
such as READID, READ0, STATUS, etc.)
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

There's no need to privately store the device page size as it's
available in mtd structure field mtd->writesize.
Also, this removes the hardcoded page size value, leaving the
auto-detected value only.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Introduce a fifo_size field to represent the size of the controller's
FIFO buffer, and use it to distinguish that size from the amount
of data bytes to be read from the FIFO.

This is important to support devices with pages larger than the
controller's internal FIFO, that need to read the pages in FIFO-sized
chunks.

In particular, the current code is at least confusing, for it mixes
all the different sizes involved: FIFO size, page size and data size.

This commit starts the cleaning by removing the info->page_size field
that is not currently used. The host->page_size field should also
be removed and use always mtd->writesize instead. Follow up commits
will clean this up.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Whenever possible, it's always better to use the generic chip->cmdfunc
instead of the internal pxa3xx_nand_cmdfunc().
In this particular case, this will allow to have multiple cmdfunc()
implementations for different SoC variants.
Reviewed-by: Huang Shijie <shijie8@gmail.com>
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

In order to customize early settings depending on the detected SoC variant,
move the detection to be before the nand_chip struct filling.

In a follow-up patch, this change is needed to detect the variant *before*
the call to alloc_nand_resource(), which allows to set a different cmdfunc()
for each variant.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

As per the ecc.read_page() prototype, we must return the maximum number
of bitflips that were corrected on any one region covering an ecc step.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

The current driver doesn't support sub-page writing, so report
that to the NAND core.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Since we have now support for the NFCv2 controller found on
Armada 370/XP platforms.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Given there's no public specification to this date, and in order
to capture some important details and singularities about the
controller let's document them once and for good.

Cc: linux-doc@vger.kernel.org
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Since the driver supports the new compatible string, the binding
documentation must be updated to reflect it.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This allows to drop a few casts.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

mtd_info.name is "const char *"
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: linux-mtd@lists.infradead.org
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

device_driver.name is "const char *"
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Olof Johansson <olof@lixom.net>
Cc: linux-mtd@lists.infradead.org
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

map_info.name is "const char *"
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: linux-mtd@lists.infradead.org
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Fix the following checkpatch warnings:

WARNING: line over 80 characters
#268: FILE: mtd/nand/gpmi-nand/gpmi-lib.c:268:
+	* consecutive reboots. The latter case has not been seen on the MX23 yet,

WARNING: space prohibited before semicolon
#356: FILE: mtd/nand/gpmi-nand/gpmi-lib.c:356:
+		(target.tRHOH_in_ns >= 0) ;

WARNING: space prohibited before semicolon
#1006: FILE: mtd/nand/gpmi-nand/gpmi-lib.c:1006:
+		BF_GPMI_TIMING0_DATA_SETUP(hw.data_setup_in_cycles)       ;
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Using devm_clk_get() can make the code smaller and cleaner.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

In default way, we use the ecc_strength/ecc_step size calculated by ourselves
and use all the OOB area.

This patch adds a new property : "fsl,use-minimum-ecc"

If we enable it, we will firstly try to use the datasheet's minimum required
ECC provided by the MTD layer (the ecc_strength_ds/ecc_step_ds fields
in the nand_chip{}). So we may have free space in the OOB area by using the
minimum ECC, and we may support JFFS2 with some SLC NANDs, such as Micron's
SLC NAND.

If we fail to use the minimum ECC, we will use the legacy method to calculate
the ecc_strength and ecc_step size.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This option does not need to depend in MTD_NAND, for it's enclosed
under it. Also, it's wrong to make it depend in ARCH_OMAP3 only
since the controller is used in a wider range of SoCs.

Instead, just leave the dependency on the OMAP2 driver option.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Acked-by: Pekon Gupta <pekon@ti.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Some flash also support quad read mode. Adding support for quad read
mode in m25p80 for Spansion and Macronix flash.

[Tweaked by Brian]

With this patch, quad-read support will override fast-read and
normal-read, if the SPI controller and flash chip both support it.
Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

This is a cleanup prior to adding quad read support. This will facilitate
easy addition of more read commands check under an enum rather that defining a
separate bool for it.
Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Pull ARM SoC fixes from Olof Johansson:
 "Another smallish batch of fixes, it's been quiet due to the holidays.
  Nothing controversial here, a handful of things across the board"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: pxa: fix USB gadget driver compilation regression
  ARM: OMAP2+: Fix LCD panel backlight regression for LDP legacy booting
  ARM: OMAP2+: hwmod_data: fix missing OMAP_INTC_START in irq data
  ARM: DRA7: hwmod: Fix boot crash with DEBUG_LL
  ARM: shmobile: r8a7790: fix shdi resource sizes
  ARM: shmobile: bockw: fixup DMA mask
  ARM: shmobile: armadillo: Add PWM backlight power supply

Pull x86 fixes from Peter Anvin:
 "There is a small EFI fix and a big power regression fix in this batch.

  My queue also had a fix for downing a CPU when there are insufficient
  number of IRQ vectors available, but I'm holding that one for now due
  to recent bug reports"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/efi: Don't select EFI from certain special ACPI drivers
  x86 idle: Repair large-server 50-watt idle-power regression

Pull ACPI and power management fixes and new device IDs from Rafael Wysocki:

 - Fix for a cpufreq regression causing stale sysfs files to be left
   behind during system resume if cpufreq_add_dev() fails for one or
   more CPUs from Viresh Kumar.

 - Fix for a bug in cpufreq causing CONFIG_CPU_FREQ_DEFAULT_* to be
   ignored when the intel_pstate driver is used from Jason Baron.

 - System suspend fix for a memory leak in pm_vt_switch_unregister()
   that forgot to release objects after removing them from
   pm_vt_switch_list.  From Masami Ichikawa.

 - Intel Valley View device ID and energy unit encoding update for the
   (recently added) Intel RAPL (Running Average Power Limit) driver from
   Jacob Pan.

 - Intel Bay Trail SoC GPIO and ACPI device IDs for the Low Power
   Subsystem (LPSS) ACPI driver from Paul Drews.

* tag 'pm+acpi-3.13-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  powercap / RAPL: add support for ValleyView Soc
  PM / sleep: Fix memory leak in pm_vt_switch_unregister().
  cpufreq: Use CONFIG_CPU_FREQ_DEFAULT_* to set initial policy for setpolicy drivers
  cpufreq: remove sysfs files for CPUs which failed to come back after resume
  ACPI: Add BayTrail SoC GPIO and LPSS ACPI IDs