- The BAM transaction is the core data structure which will be used
for all the data transfers in QPIC NAND. Since the core framework
in nand_base.c is serializing all the NAND requests so allocating
BAM transaction before every transfer will be overhead. The memory
for it be allocated during probe time and before every transfer,
it will be cleared.
- The BAM transaction contains the array of
command and data scatter gather list and indexes. For
every transfer, all the resource will be taken from BAM
transaction.
- The size of the buffer used for BAM transactions
is calculated based on the NAND device with the maximum page size,
among all the devices connected to the
controller.
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
The EBI2 NAND controller directly remaps register read buffer with
dma_map_sg and DMA address of this buffer will be passed to DMA
API’s. While, on QPIC NAND controller, which uses BAM DMA, we read
the controller registers by preparing a BAM command descriptor. This
command descriptor requires the
- controller register address
- the DMA address in which we want to store the value read
back from the controller register.
This command descriptor will be remapped with dma_map_sg
and its DMA address will be passed to DMA API’s. Therefore,
it's required that we also map our register read buffer for
DMA (using dma_map_single). We use the returned DMA address
for preparing entries in our command descriptor.
This patch adds the DMA mapping support for register read
buffer. This buffer will be DMA mapped during allocation
time. Before starting of any operation, this buffer will
be synced for device operation and after operation
completion, it will be synced again for CPU.
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
1. QPIC NAND controller uses 3 BAM channels: command, data tx
and data rx while EBI2 NAND controller uses only single ADM
channel.
2. CRCI is only required for ADM DMA and it's not required for
BAM DMA.
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
The current driver only supports EBI2 NAND controller which uses
ADM DMA. The latest QCOM SoC uses QPIC NAND controller with BAM
DMA. NAND registers and programming sequence are same for EBI2
and QPIC NAND so the same driver can support QPIC NAND also by
adding the BAM DMA support. This patch adds the is_bam in NAND
property which will be checked for determining the DMA engine type.
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Currently driver data is being assigned directly with ECC modes.
Now, the plan is to add more NAND controller versions which will
have different properties. This patch reorganizes the current driver
data assignment by creating NAND controller properties structure
which will contain all properties specific to NAND controller.
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
The NAND page read fails without complete boot chain since
NAND_DEV_CMD_VLD value is not proper. The default power on reset
value for this register is
0xe - ERASE_START_VALID | WRITE_START_VALID | READ_STOP_VALID
The READ_START_VALID should be enabled for sending PAGE_READ
command. READ_STOP_VALID should be cleared since normal NAND
page read does not require READ_STOP command.
Fixes: c76b78d8ec ("mtd: nand: Qualcomm NAND controller driver")
Cc: stable@vger.kernel.org
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
The NAND controller can support multiple NAND devices having different
page sizes. Future code will require us to allocate memory based on the
maximum number of codewords among all the devices. We reorganize the
NAND device probing such that the ONFI parameters are first read for
each connected device to identify the maximum number of codewords
possible, and only then proceed with MTD device registration (i.e, call
nand_scan_tail and mtd_device_register).
This is a reorganization of the existing code and will not change any
functionality.
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
The memset in clear_read_regs is overhead. All the register data
will be filled by DMA during NAND operation so making these
register variables zero is not required.
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Each NAND page consist of multiple codewords. Following is
sequence for NAND page write according to hardware guide.
1. Program Power-up configuration, page row, page column
address and flash configuration registers.
2. Write NAND_FLASH_CMD followed by NANC_EXEC_CMD for each
codeword.
3. Read NAND_FLASH_STATUS for each codeword.
The step 1 should be done once for each page and step 2,3 should
be done for each codeword.
Currently, all the 3 steps are being done for each codeword which
is wrong. Now this patch reorganizes page write functions to
configure page specific register once and per codeword specific
registers for each NAND ECC step.
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Each NAND page consist of multiple codewords. Following is
sequence for NAND page read according to hardware guide.
1. Program Power-up configuration, page row, page column
address and flash configuration registers.
2. Write NAND_FLASH_CMD followed by NANC_EXEC_CMD for each
codeword.
3. Read NAND_FLASH_STATUS for each codeword.
The step 1 should be done once for each page and step 2,3 should
be done for each codeword.
Currently, all the 3 steps are being done for each codeword which
is wrong. Now this patch reorganizes read page functions to
configure page specific register once and per codeword specific
registers for each NAND ECC step.
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Currently the compatible “qcom,nandcs” is being used for each
connected NAND device to support for multiple NAND devices in the
same bus. The same thing can be achieved by looking reg property
for each sub nodes which contains the chip select number so this
patch removes the use of “qcom,nandcs” for specifying NAND device
sub nodes.
Since there is no user for this driver currently in so
changing compatible string is safe.
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
The configuration for BCH is not correct in the current driver.
The ECC_CFG_ECC_DISABLE bit defines whether to enable or disable the
BCH ECC in which
0x1 : BCH_DISABLED
0x0 : BCH_ENABLED
But currently host->bch_enabled is being assigned to BCH_DISABLED.
Fixes: c76b78d8ec ("mtd: nand: Qualcomm NAND controller driver")
Cc: stable@vger.kernel.org
Signed-off-by: Abhishek Sahu <absahu@codeaurora.org>
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
A lot of drivers are providing their own ->cmdfunc(), and most of the
time this implementation does not support all possible NAND operations.
But since ->cmdfunc() cannot return an error code, the core has no way
to know that the operation it requested is not supported.
This is a problem we cannot address for all kind of operations with the
current design, but we can prevent these silent failures for the
GET/SET FEATURES operation by overloading the default
->onfi_{set,get}_features() methods with one returning -ENOTSUPP.
Reported-by: Chris Packham <Chris.Packham@alliedtelesis.co.nz>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Chris Packham <Chris.Packham@alliedtelesis.co.nz>
The code to initialize a struct nand_hw_control is duplicated across
several drivers. Factorize it using an inline function.
Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Implementing the mtd_ooblayout_ops interface is the new way of exposing
ECC/OOB layout to MTD users.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Archit Taneja <architt@codeaurora.org>
The mtd_ooblayout_xxx() helper functions have been added to avoid direct
accesses to ecclayout fields, and thus ease for future reworks.
Use these helpers in all places where the oobfree[] and eccpos[] arrays
where directly accessed.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Tested-by: Archit Taneja <architt@codeaurora.org>
Some drivers are including linux/of_mtd.h even if they don't use any of
the of_get_nand_xxx() helpers.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Harvey Hunt <harvey.hunt@imgtec.com>
The Qualcomm NAND controller is found in SoCs like IPQ806x, MSM7xx,
MDM9x15 series.
It exists as a sub block inside the IPs EBI2 (External Bus Interface 2)
and QPIC (Qualcomm Parallel Interface Controller). These IPs provide a
broader interface for external slow peripheral devices such as LCD and
NAND/NOR flash memory or SRAM like interfaces.
We add support for the NAND controller found within EBI2. For the SoCs
of our interest, we only use the NAND controller within EBI2. Therefore,
it's safe for us to assume that the NAND controller is a standalone block
within the SoC.
The controller supports 512B, 2kB, 4kB and 8kB page 8-bit and 16-bit NAND
flash devices. It contains a HW ECC block that supports BCH ECC (4, 8 and
16 bit correction/step) and RS ECC(4 bit correction/step) that covers main
and spare data. The controller contains an internal 512 byte page buffer
to which we read/write via DMA. The EBI2 type NAND controller uses ADM DMA
for register read/write and data transfers. The controller performs page
reads and writes at a codeword/step level of 512 bytes. It can support up
to 2 external chips of different configurations.
The driver prepares register read and write configuration descriptors for
each codeword, followed by data descriptors to read or write data from the
controller's internal buffer. It uses a single ADM DMA channel that we get
via dmaengine API. The controller requires 2 ADM CRCIs for command and
data flow control. These are passed via DT.
The ecc layout used by the controller is syndrome like, but we can't use
the standard syndrome ecc ops because of several reasons. First, the amount
of data bytes covered by ecc isn't same in each step. Second, writing to
free oob space requires us writing to the entire step in which the oob
lies. This forces us to create our own ecc ops.
One more difference is how the controller accesses the bad block marker.
The controller ignores reading the marker when ECC is enabled. ECC needs
to be explicity disabled to read or write to the bad block marker. The
nand_bbt helpers library hence can't access BBMs for the controller.
For now, we skip the creation of BBT and populate chip->block_bad and
chip->block_markbad helpers instead.
Reviewed-by: Andy Gross <agross@codeaurora.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
