The Samsung serial driver registered for CPU frequency transitions to
recalculate its clock when ARM clock frequency changes. This is needed
only on S3C24xx platform so limit the ifdef to respective cpufreq
driver.
On S3C24xx the ratio ratio between frequencies of UART's parent clock
(pclk) and ARM's parent clock (fclk) remains fixed. Therefore when ARM
clock frequency goes down, the serial is also affected.
Suggested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This driver makes use of the __set_bit() and __clear_bit() functions.
When running under big-endian, these functions don't convert the bit
indexes when working with peripheral registers, leading to the
incorrect bits being set and cleared when running big-endian.
Add two new driver functions for setting and clearing bits that are
byte-order aware.
Signed-off-by: Matthew Leach <matthew@mattleach.net>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix the serial access code to deal with kernels built for big endian
operation.
Signed-off-by: Matthew Leach <matthew@mattleach.net>
Acked-by: Ben Dooks <ben.dooks@codethink.co.uk>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Due to some of serial ports can have FIFO size smaller than cache line
size, and because of need to align DMA buffer address to cache line size,
it's necessary to calculate minimum number of bytes for which we want
to start DMA transaction to be at least cache line size. The simplest
way to meet this requirement is to get maximum of cache line size and
FIFO size.
Cc: <stable@vger.kernel.org> # v3.18+
Reported-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add RX DMA transfers support for samsung serial driver. It's enabled
when DMA controller for RX channel is specified in device-tree.
DMA transactions are started when number of bytes in RX FIFO reaches
trigger level, otherwise PIO mode is used. DMA transfer size is always
PAGE_SIZE which can cause large latency when smaller data amount is
transferred, so we always terminate DMA transaction on RX timeout
interrupt. Timeout interval is set to 64 frame times.
Based on previous work of Sylwester Nawrocki and Lukasz Czerwinski.
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add TX DMA transfers support for samsung serial driver. It's enabled
when "dmas" property is defined in serial device-tree node, otherwise
TX transfers are prerformed using PIO.
TX DMA is used for data segments larger than fifosize to reduce number
of interrupts during data transmission. For buffers shorter than fifosize
PIO mode is selected.
Data blocks for DMA transfers are aligned to cache line size to avoid
problems with coherency (some areas of TX circ buffer can be used by
CPU during DMA transaction, so we have to ensure that our data is always
consistent).
Based on previous work of Sylwester Nawrocki and Lukasz Czerwinski.
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This struct contains DMA configuration for each serial port.
It will be used in next commits adding DMA support in driver.
Based on previous work of Sylwester Nawrocki and Lukasz Czerwinski.
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add format and argument checking and fix misuses in the dbg macro.
Add __printf
Use %pR for resource
Add #include guard to samsung.h
Move static functions from .h to .c
Use vscnprintf instead of length unguarded vsprintf
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Casting the return value which is a void pointer is redundant.
The conversion from void pointer to any other pointer type is
guaranteed by the C programming language.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
port->membase is (unsigned char __iomem *), not (unsigned long *)
__set_bit() uses (unsigned long *) as the second argument.
Thus, casting (unsigned long *)(unsigned long) is necessary
to fix the following sparse warnings.
drivers/tty/serial/samsung.c:142:33: warning: cast removes address space of expression
drivers/tty/serial/samsung.c:161:33: warning: cast removes address space of expression
drivers/tty/serial/samsung.c:176:33: warning: cast removes address space of expression
drivers/tty/serial/samsung.c:526:40: warning: cast removes address space of expression
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There are a few bugs in the samsung serial driver when built as a
loadable module, which makes the console code unavailable, as well as
giving no access to the 'printascii' early debug function. This adds
the appropriate compile time conditionals.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With reset port, set clock and get clock functions in SoC specific extentions
being removed, only the driver probe is left over in these extensions. The
probe function itself can be merged into one and moved into the samsung common
serial driver. With driver probe also moved, all the SoC specific extentions
are no longer required and they are deleted.
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
With clkdev based clock lookup support, the clock set and get operation
using clock names communicated between the samsung uart driver and the
SoC specific extension can be removed.
In addition to that, for each platform specific extension, add the
default clock selection, number of clock options for uart baud generator,
clock selection bit mask and shift values which is required by the
clkdev support in samsung uart driver.
The default clock selection value 'def_clk_sel' specifies the default clock
to be used as the source clock for baud rate generator in case the platform
code does not specify the same.
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
With clkdev based clock lookup added to samsung serial driver, the use
of 'struct s3c24xx_uart_clksrc' to supply clock names in platform
data is removed from all the Samsung platform code.
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Ramax Lo <ramaxlo@gmail.com>
Cc: Vasily Khoruzhick <anarsoul@gmail.com>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Instead of using clock names supplied in platform data, use a generic
clock name 'clk_uart_baud' to look up clocks. The platform code should
register clocks with the name 'clk_uart_baud' which can be used by the
baud rate generator. The clock lookup and selection of the best clock
as baud rate clock is reworked.
Platform code can specify the clocks that can be used as source for the
baud clock (as supported previously by passing names of clocks). A new
member is added to the platform data 'clk_sel' which holds a bit-field
value with each bit representing a baud source clock. If a bit at any
bit position is set, that clock is looked up to participate in the
selection of the baud clock source.
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Add a pointer to the location of the platform data in the driver's private
data. When instantiated using device tree, pdev->dev->platform_data does not
necessarily point to a valid instance of platform data. The platform data
pointer in the driver's private data could be set to pdev->dev->platform_data
or platform data instance created from device tree.
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
s3c64xx and later SoC's include the interrupt mask and pending registers
in the uart controller, unlike the s3c24xx SoC's which have these registers
in the interrupt controller. When the mask and pending registers are part
of the uart controller, a unified interrupt handler can handle the tx/rx
interrupt. With this, the static reservation of interrupt numbers for the
uart tx/rx/err interrupts in the linux irq space is not required and
simplifies adding device tree support.
Suggested-by: Grant Likely <grant.likely@secretlab.ca>
CC: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Uart port is registered as a console during the driver's probe.
So explict registration of console with console_initcall is
removed.
Signed-off-by: Thomas Abraham <thomas.ab@samsung.com>
[kgene.kim@samsung.com: removed changes of s3c2400 and s3c24a0]
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
remove invalid location line in each file header after location
moved from driver/char to driver/tty
Signed-off-by: Jovi Zhang <bookjovi@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The serial drivers are really just tty drivers, so move them to
drivers/tty/ to make things a bit neater overall.
This is part of the tty/serial driver movement proceedure as proposed by
Arnd Bergmann and approved by everyone involved a number of months ago.
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Rogier Wolff <R.E.Wolff@bitwizard.nl>
Cc: Michael H. Warfield <mhw@wittsend.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Krzysztof Kozlowski