Commit Graph

116 Commits

Author SHA1 Message Date
Marek Szyprowski 469f813ffe serial: samsung: Remove useless spinlock
Spinlock taken only for dma_map_single() for TX buffer is completely
useless and doesn't protect anything, so remove it to simplify the code.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 18:58:52 +02:00
Marek Szyprowski 500fcc08a3 serial: samsung: Add missing checks for dma_map_single failure
This patch adds missing checks for dma_map_single() failure and proper error
reporting. Although this issue was harmless on ARM architecture, it is always
good to use the DMA mapping API in a proper way. This patch fixes the following
DMA API debug warning:

WARNING: CPU: 1 PID: 3785 at lib/dma-debug.c:1171 check_unmap+0x8a0/0xf28
dma-pl330 121a0000.pdma: DMA-API: device driver failed to check map error[device address=0x000000006e0f9000] [size=4096 bytes] [mapped as single]
Modules linked in:
CPU: 1 PID: 3785 Comm: (agetty) Tainted: G        W       4.11.0-rc1-00137-g07ca963-dirty #59
Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[<c011aaa4>] (unwind_backtrace) from [<c01127c0>] (show_stack+0x20/0x24)
[<c01127c0>] (show_stack) from [<c06ba5d8>] (dump_stack+0x84/0xa0)
[<c06ba5d8>] (dump_stack) from [<c0139528>] (__warn+0x14c/0x180)
[<c0139528>] (__warn) from [<c01395a4>] (warn_slowpath_fmt+0x48/0x50)
[<c01395a4>] (warn_slowpath_fmt) from [<c072a114>] (check_unmap+0x8a0/0xf28)
[<c072a114>] (check_unmap) from [<c072a834>] (debug_dma_unmap_page+0x98/0xc8)
[<c072a834>] (debug_dma_unmap_page) from [<c0803874>] (s3c24xx_serial_shutdown+0x314/0x52c)
[<c0803874>] (s3c24xx_serial_shutdown) from [<c07f5124>] (uart_port_shutdown+0x54/0x88)
[<c07f5124>] (uart_port_shutdown) from [<c07f522c>] (uart_shutdown+0xd4/0x110)
[<c07f522c>] (uart_shutdown) from [<c07f6a8c>] (uart_hangup+0x9c/0x208)
[<c07f6a8c>] (uart_hangup) from [<c07c426c>] (__tty_hangup+0x49c/0x634)
[<c07c426c>] (__tty_hangup) from [<c07c78ac>] (tty_ioctl+0xc88/0x16e4)
[<c07c78ac>] (tty_ioctl) from [<c03b5f2c>] (do_vfs_ioctl+0xc4/0xd10)
[<c03b5f2c>] (do_vfs_ioctl) from [<c03b6bf4>] (SyS_ioctl+0x7c/0x8c)
[<c03b6bf4>] (SyS_ioctl) from [<c010b4a0>] (ret_fast_syscall+0x0/0x3c)

Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Fixes: 62c37eedb7 ("serial: samsung: add dma reqest/release functions")
CC: stable@vger.kernel.org # v4.10+
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 18:58:52 +02:00
Marek Szyprowski 768d64f491 serial: samsung: Use right device for DMA-mapping calls
Driver should provide its own struct device for all DMA-mapping calls instead
of extracting device pointer from DMA engine channel. Although this is harmless
from the driver operation perspective on ARM architecture, it is always good
to use the DMA mapping API in a proper way. This patch fixes following DMA API
debug warning:

WARNING: CPU: 0 PID: 0 at lib/dma-debug.c:1241 check_sync+0x520/0x9f4
samsung-uart 12c20000.serial: DMA-API: device driver tries to sync DMA memory it has not allocated [device address=0x000000006df0f580] [size=64 bytes]
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.11.0-rc1-00137-g07ca963 #51
Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[<c011aaa4>] (unwind_backtrace) from [<c01127c0>] (show_stack+0x20/0x24)
[<c01127c0>] (show_stack) from [<c06ba5d8>] (dump_stack+0x84/0xa0)
[<c06ba5d8>] (dump_stack) from [<c0139528>] (__warn+0x14c/0x180)
[<c0139528>] (__warn) from [<c01395a4>] (warn_slowpath_fmt+0x48/0x50)
[<c01395a4>] (warn_slowpath_fmt) from [<c0729058>] (check_sync+0x520/0x9f4)
[<c0729058>] (check_sync) from [<c072967c>] (debug_dma_sync_single_for_device+0x88/0xc8)
[<c072967c>] (debug_dma_sync_single_for_device) from [<c0803c10>] (s3c24xx_serial_start_tx_dma+0x100/0x2f8)
[<c0803c10>] (s3c24xx_serial_start_tx_dma) from [<c0804338>] (s3c24xx_serial_tx_chars+0x198/0x33c)

Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Fixes: 62c37eedb7 ("serial: samsung: add dma reqest/release functions")
CC: stable@vger.kernel.org # v4.0+
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 18:58:52 +02:00
Krzysztof Kozlowski f98c7bce57 serial: samsung: Continue to work if DMA request fails
If DMA is not available (even when configured in DeviceTree), the driver
will fail the startup procedure thus making serial console not
available.

For example this causes boot failure on QEMU ARMv7 (Exynos4210, SMDKC210):
    [    1.302575] OF: amba_device_add() failed (-19) for /amba/pdma@12680000
    ...
    [   11.435732] samsung-uart 13800000.serial: DMA request failed
    [   72.963893] samsung-uart 13800000.serial: DMA request failed
    [   73.143361] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000000

DMA is not necessary for serial to work, so continue with UART startup
after emitting a warning.

Fixes: 62c37eedb7 ("serial: samsung: add dma reqest/release functions")
Cc: <stable@vger.kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-07 19:58:37 +01:00
남영민 a8a1781b87 serial: samsung: enable clock before accessing interrupt mask resister
Ensure that the uart clock is enabled prior to writing to the
interrupt mask register in s3c24xx_serial_resume_noirq function.
Without enabing the uart clock, the uart register cannot be accessed.

Signed-off-by: Youngmin Nam <youngmin.nam@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-03 10:12:16 +01:00
Marek Szyprowski ba3d6f8f10 serial: samsung: Simplify DMA engine initialization code
dma_request_slave_channel_compat() requires filter function and mask, which
are not needed on device tree based platforms, so simplify the code by
calling the more appropriate dma_request_chan() function. This additionally
gives us proper error handling, because the new function returns error
codes instead of NULL on failure.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-12 11:51:24 +01:00
Krzysztof Kozlowski ebaa81c728 serial: samsung: Register cpufreq notifier only on S3C24xx
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>
2016-08-31 15:39:58 +02:00
Matthew Leach bbb5ff9122 tty: serial: samsung: add byte-order aware bit functions
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>
2016-06-25 14:04:12 -07:00
Krzysztof Kozlowski 926b7b5122 serial: samsung: Fix possible out of bounds access on non-DT platform
On non-DeviceTree platforms, the index of serial device is a static
variable incremented on each probe.  It is incremented even if deferred
probe happens when getting the clock in s3c24xx_serial_init_port().

This index is used for referencing elements of statically allocated
s3c24xx_serial_ports array.  In case of re-probe, the index will point
outside of this array leading to memory corruption.

Increment the index only on successful probe.

Reported-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Fixes: b497549a03 ("[ARM] S3C24XX: Split serial driver into core and per-cpu drivers")
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25 13:50:53 -07:00
Krzysztof Kozlowski e51e4d8a18 serial: samsung: Fix ERR pointer dereference on deferred probe
When the clk_get() of "uart" clock returns EPROBE_DEFER, the next re-probe
finishes with success but uses invalid (ERR_PTR) values.  This leads to
dereferencing of ERR_PTR stored under ourport->clk:

	12c30000.serial: Controller clock not found
	(...)
	12c30000.serial: ttySAC3 at MMIO 0x12c30000 (irq = 61, base_baud = 0) is a S3C6400/10
	Unable to handle kernel paging request at virtual address fffffdfb

	(clk_prepare) from [<c039f7d0>] (s3c24xx_serial_pm+0x20/0x128)
	(s3c24xx_serial_pm) from [<c0395414>] (uart_change_pm+0x38/0x40)
	(uart_change_pm) from [<c039689c>] (uart_add_one_port+0x31c/0x44c)
	(uart_add_one_port) from [<c03a035c>] (s3c24xx_serial_probe+0x2a8/0x418)
	(s3c24xx_serial_probe) from [<c03ee110>] (platform_drv_probe+0x50/0xb0)
	(platform_drv_probe) from [<c03ecb44>] (driver_probe_device+0x1f4/0x2b0)
	(driver_probe_device) from [<c03eb0c0>] (bus_for_each_drv+0x44/0x8c)
	(bus_for_each_drv) from [<c03ec8c8>] (__device_attach+0x9c/0x100)
	(__device_attach) from [<c03ebf54>] (bus_probe_device+0x84/0x8c)
	(bus_probe_device) from [<c03ec388>] (deferred_probe_work_func+0x60/0x8c)
	(deferred_probe_work_func) from [<c012fee4>] (process_one_work+0x120/0x328)
	(process_one_work) from [<c0130150>] (worker_thread+0x2c/0x4ac)
	(worker_thread) from [<c0135320>] (kthread+0xd8/0xf4)
	(kthread) from [<c0107978>] (ret_from_fork+0x14/0x3c)

The first unsuccessful clk_get() causes s3c24xx_serial_init_port() to
exit with failure but the s3c24xx_uart_port is left half-configured
(e.g. port->mapbase is set, clk contains ERR_PTR).  On next re-probe,
the function s3c24xx_serial_init_port() will exit early with success
because of configured port->mapbase and driver will use old values,
including the ERR_PTR as clock.

Fix this by cleaning the port->mapbase on error path so each re-probe
will initialize all of the port settings.

Fixes: 60e9357547 ("serial: samsung: enable clock before clearing pending interrupts during init")
Cc: <stable@vger.kernel.org>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Tested-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25 13:50:53 -07:00
Chanwoo Choi b8995f527a serial: samsung: Reorder the sequence of clock control when call s3c24xx_serial_set_termios()
This patch fixes the broken serial log when changing the clock source
of uart device. Before disabling the original clock source, this patch
enables the new clock source to protect the clock off state for a split second.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 09:26:55 -07:00
Youngmin Nam aba06e9222 serial: samsung: optimize UART rx fifo access routine
This patch optimizes UART rx fifo access routine by reading UART SFR
when necessary. At first, the "fifocnt" variable will be initialized
as Rx FIFO count. So we don't need to access UFSTAT(FIFO status) register
every time to check FIFO count because we know that count with "fifocnt".
After all data were read out from Rx FIFO, the "fifocnt" will be set as 0.
Lastly, UFSTAT will be accessed again to check whether the data remains
by any chance.

Signed-off-by: Youngmin Nam <ym0914@gmail.com>
Reviewed-by: Jung-Ick Guack <ji.guack@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-07 16:11:14 -08:00
Peter Hurley 2eaa790989 earlycon: Use common framework for earlycon declarations
Use a single common table of struct earlycon_id for both command line
and devicetree. Re-define OF_EARLYCON_DECLARE() macro to instance a
unique earlycon declaration (the declaration is only guaranteed to be
unique within a compilation unit; separate compilation units must still
use unique earlycon names).

The semantics of OF_EARLYCON_DECLARE() is different; it declares an
earlycon which can matched either on the command line or by devicetree.
EARLYCON_DECLARE() is semantically unchanged; it declares an earlycon
which is matched by command line only. Remove redundant instances of
EARLYCON_DECLARE().

This enables all earlycons to properly initialize struct console
with the appropriate name and index, which improves diagnostics and
enables direct earlycon-to-console handoff.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-06 22:07:37 -08:00
Robert Baldyga 09557c0169 serial: samsung: Fix UART status handling in DMA mode
So far, when interrupt occured in DMA mode, it was handled by terminating
DMA transfer and draining data remaining in RX FIFO. It worked well
until interrupt was caused by timeout, but the same interrupt can be
alse caused by special condition (eg. 'break'), which requires special
handling. In such case handling mechanism was the same - DMA transaction
was terminated and FIFO was drained, but any special conditions were
ingnored. Because of this in DMA mode there was no ability to use,
for example, Magic SysRq.

This patch fixes this problem by using s3c24xx_serial_rx_drain_fifo()
function instead of uart_rx_drain_fifo(), which does the same thing
(drains RX FIFO) plus checks UART status to detect special conditions
(such as 'break'). Thanks to this we have exactly the same UART status
handling in both DMA and PIO mode.

This change additionally simplifies RX handling code, as we no longer
need uart_rx_drain_fifo() function, so we can remove it.

Reported-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>
2015-10-04 17:44:52 +01:00
Robert Baldyga 01732dd25c serial: samsung: introduce s3c24xx_serial_rx_drain_fifo() function
This patch introduces s3c24xx_serial_rx_drain_fifo() which reads data
from RX FIFO and writes it to tty buffer. It also checks for special
conditions (such as 'break') and handles it. This function has been
separated from s3c24xx_serial_rx_chars_pio() as it contains code which
can be used also in DMA mode.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:44:52 +01:00
Robert Baldyga 620bb21448 serial: samsung: remove unneded 'ignore_char' label
This label does nothing special and we don't need to have it anymore.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:44:52 +01:00
Robert Baldyga e4678afeff serial: samsung: remove unused 'irq' parameter
This parameter is not used anywhere, so we can get rid of it.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 17:44:52 +01:00
Robert Baldyga 736cd79f48 serial: samsung: fix DMA for FIFO smaller than cache line size
So far DMA mode were activated when only number of bytes to send was
equal or greater than min_dma_size. Due to requirement that DMA transaction
buffer should be aligned to cache line size, the excessive bytes were
written to FIFO before starting DMA transaction. The problem occurred
when FIFO size were smaller than cache alignment, because writing all
excessive bytes to FIFO would fail. It happened in DMA mode when PIO
interrupts disabled, which caused driver hung.

The solution is to test if buffer is alligned to cache line size before
activating DMA mode, and if it's not, running PIO mode to align buffer
and then starting DMA transaction. In PIO mode, when interrupts are
enabled, lack of space in FIFO isn't the problem, so buffer aligning
will always finish with success.

Cc: <stable@vger.kernel.org> # v3.18+
Reported-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-04 22:07:24 -07:00
Marek Szyprowski 81ccb2a69f serial: samsung: fix DMA mode enter condition for small FIFO sizes
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>
2015-08-04 22:07:23 -07:00
Javier Martinez Canillas 97d49add8b serial: samsung: Remove redundant DEBUG_LL check
Commit 84f57d9e36 ("tty: serial/samsung: fix modular build") fixed
build issues when the driver was built as a module. One of those was
that printascii is only accessible when the driver is built-in.

But there is no need to check for defined(CONFIG_DEBUG_LL) since the
SERIAL_SAMSUNG_DEBUG Kconfig symbol already depends on DEBUG_LL.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: Kukjin Kim <kgene@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-23 18:27:41 -07:00
Krzysztof Kozlowski 24ee4df122 serial: samsung: Constify platform_device_id
The platform_device_id is not modified by the driver and core uses it as
const.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-10 19:08:16 +02:00
Krzysztof Kozlowski 75781979f8 serial: samsung: Staticize local symbol
Staticize symbols not exported and not used outside of file.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-10 19:08:16 +02:00
Robert Baldyga 31c6ba97d1 serial: samsung: fix serial console break
This patch fixes problems with serial console break. When function
s3c64xx_serial_startup() was started while serial console has been working,
it caused lose of characters written to TX FIFO. This effect was particularly
observable with systemd, which closes serial port every time when it's
not currently needed, hence function s3c64xx_serial_startup() is called
quite often there. To fix this problem we avoid resetting TX FIFO if port is
used as serial console.

Example of broken console log:

[ 1086.7         Expecting device dev-ttySAC1.device...
[ 1086.[  OK  ] Reached target Paths.
[ 1086.756416] s[  OK  ] Reached target Swap.
[ 1086.776413] systemd[1]: Reached target Swap.
[ 1086.776642] systemd[1]: Starting Root Slice.
[    5.53403[  OK  ] Created slice Root Slice.
[    5.548433] systemd[1]: Create[  OK  ] Created slice User and Session Slice.
[    5.568414] sys[  OK  ] Listening on /dev/initctl Compatibility Named Pipe.
[    5.588388] s[  OK  ] Listening on Delayed Shutdown Socket.
[    5.608376] sy[  OK  ] Listening on Journal Socket (/dev/log).
[    5.628361] [  OK  ] Listening on udev Kernel Socket.
[    5.648357] s[  OK  ] Listening on udev Control Socket.
[    5.668353] s[  OK  ] Listening on Journal Socket.
[    5.688366] systemd[1]: Listeni[  OK  ] Created slice System Slice.
[    5.708393]          Mounting Temporary Directory...
[ 7139.067436]          Starting prepare device daemon...
[ 7139.091726] sy         Starting Generate environment from /etc/profile.d...
[    5.792867] system         Starting Create Static Device Nodes in /dev...
[ 7848.718         Mounting Debug File System...
[ 7848.7384         Mounting Configuration File System...
[    5.852         Starting Apply Kernel Variables...
[    5.8720         Starting Setup Virtual Console...
[ 7848.798         Starting udev Coldplug all Devices...
[ 7848.817         Starting Journal Service...
[  OK  ] Started Journal Service.
[ 7848.854222] s[  OK  ] Reached target Slices.
         Starting Remount Root and Kernel File Systems...
[  OK  ] Mounted Configuration File System.

Reported-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-04-28 14:27:38 +02:00
Javier Martinez Canillas e91d863d1a serial: samsung: Clear operation mode on UART shutdown
Exynos serial ports operate either in a DMA-based or interrupt-based
modes. In DMA-based mode, the UART generates a transfer data request
and a Transmission (Tx) interrupt in interrupt-based mode.

The Tx IRQ is only unmasked in interrupt-based mode and it was done
in s3c24xx_serial_start_tx(). Commit ba019a3e2a ("serial: samsung:
remove redundant interrupt enabling") removed the IRQ enable on that
function since it is enabled when the mode is set in enable_tx_pio().

The problem is that enable_tx_pio() is only called if the port mode
has not been set before but the mode was not cleared on .shutdown().

So if the UART was shutdown and then started up again, the mode set
will remain and the Tx IRQ won't be unmasked.

This caused a hang on at least Exynos5250, Exynos5420 and Exynos5800
when the system is rebooted or powered off.

Fixes: ba019a3e2a ("serial: samsung: remove redundant interrupt enabling")
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-03-26 23:13:14 +01:00
Marek Szyprowski c3bda295ee serial: samsung: earlycon support depends on CONFIG_SERIAL_SAMSUNG_CONSOLE
EarlyCon support depends on serial console infrastructure, so the code
implementing it should depend on CONFIG_SERIAL_SAMSUNG_CONSOLE.

This patch fixes the following build break:
CC [M]  drivers/tty/serial/samsung.o
drivers/tty/serial/samsung.c:2468:1: error: expected declaration specifiers or ‘...’ before string constant
drivers/tty/serial/samsung.c:2468:1: error: expected declaration specifiers or ‘...’ before ‘s3c2410_setup_earlycon’
drivers/tty/serial/samsung.c:2487:1: error: expected declaration specifiers or ‘...’ before string constant
drivers/tty/serial/samsung.c:2487:1: error: expected declaration specifiers or ‘...’ before ‘s3c2412_setup_earlycon’
drivers/tty/serial/samsung.c:2488:1: error: expected declaration specifiers or ‘...’ before string constant
drivers/tty/serial/samsung.c:2488:1: error: expected declaration specifiers or ‘...’ before ‘s3c2440_setup_earlycon’
drivers/tty/serial/samsung.c:2489:1: error: expected declaration specifiers or ‘...’ before string constant
drivers/tty/serial/samsung.c:2489:1: error: expected declaration specifiers or ‘...’ before ‘s3c6400_setup_earlycon’
drivers/tty/serial/samsung.c:2506:1: error: expected declaration specifiers or ‘...’ before string constant
drivers/tty/serial/samsung.c:2506:1: error: expected declaration specifiers or ‘...’ before ‘s5pv210_setup_earlycon’
drivers/tty/serial/samsung.c:2507:1: error: expected declaration specifiers or ‘...’ before string constant
drivers/tty/serial/samsung.c:2507:1: error: expected declaration specifiers or ‘...’ before ‘exynos4210_setup_earlycon’
drivers/tty/serial/samsung.c:2468:1: warning: ‘s3c2410_setup_earlycon’ defined but not used [-Wunused-function]
drivers/tty/serial/samsung.c:2487:1: warning: ‘s3c2412_setup_earlycon’ defined but not used [-Wunused-function]
drivers/tty/serial/samsung.c:2488:1: warning: ‘s3c2440_setup_earlycon’ defined but not used [-Wunused-function]
drivers/tty/serial/samsung.c:2489:1: warning: ‘s3c6400_setup_earlycon’ defined but not used [-Wunused-function]
drivers/tty/serial/samsung.c:2506:1: warning: ‘s5pv210_setup_earlycon’ defined but not used [-Wunused-function]
drivers/tty/serial/samsung.c:2507:1: warning: ‘exynos4210_setup_earlycon’ defined but not used [-Wunused-function]
make[3]: *** [drivers/tty/serial/samsung.o] Error 1

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 11:11:00 -08:00
Robert Baldyga ba019a3e2a serial: samsung: remove redundant interrupt enabling
Function s3c24xx_serial_start_tx_pio() enables interrupts if needed,
so we don't have to (or even we shouldn't) enable them before.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:28 -08:00
Tomasz Figa b94ba0328d serial: samsung: Add support for early console
This patch adds support for early console initialized from device tree
and kernel command line to all variants of Samsung serial driver.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
[mszyprow: added support for command line based initialization,
           fixed comments, added documentation]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Tested-by: Alim Akhtar <alim.akhtar@samsung.com>
Tested-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-02 10:11:26 -08:00
Greg Kroah-Hartman 61b6b7fbda Merge 3.19-rc5 into tty-next
We want those tty fixes in that release in this branch as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-19 07:02:50 +08:00
Robert Baldyga b543c301c2 serial: samsung: add DMA support for RX
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>
2015-01-09 14:25:39 -08:00
Robert Baldyga 29bef79908 serial: samsung: add DMA support for TX
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>
2015-01-09 14:25:39 -08:00
Robert Baldyga 62c37eedb7 serial: samsung: add dma reqest/release functions
Add functions requesting and releasing RX and TX DMA channels. This
function are called only when "dmas" property in serial device-tree
node is defined.

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>
2015-01-09 14:25:39 -08:00
Robert Baldyga 658c9d2b73 serial: samsung: alloc dma stucture in ourport
When we have "dmas" property in serial node in device-tree, we do
memory alocation for dma structure which will be used in DMA handling
code.

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>
2015-01-09 14:25:39 -08:00
Chanwoo Choi 31ec77aca7 serial: samsung: Add the support for Exynos5433 SoC
This patch adds new s3c24xx_serial_drv_data structure for Exynos5433 SoC
because Exynos5433 has different fifo size from existing Exynos4 SoC.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Acked-by: Inki Dae <inki.dae@samsung.com>
Acked-by: Geunsik Lim <geunsik.lim@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-01-09 13:46:02 -08:00
Linus Torvalds e6b5be2be4 Driver core patches for 3.19-rc1
Here's the set of driver core patches for 3.19-rc1.
 
 They are dominated by the removal of the .owner field in platform
 drivers.  They touch a lot of files, but they are "simple" changes, just
 removing a line in a structure.
 
 Other than that, a few minor driver core and debugfs changes.  There are
 some ath9k patches coming in through this tree that have been acked by
 the wireless maintainers as they relied on the debugfs changes.
 
 Everything has been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core update from Greg KH:
 "Here's the set of driver core patches for 3.19-rc1.

  They are dominated by the removal of the .owner field in platform
  drivers.  They touch a lot of files, but they are "simple" changes,
  just removing a line in a structure.

  Other than that, a few minor driver core and debugfs changes.  There
  are some ath9k patches coming in through this tree that have been
  acked by the wireless maintainers as they relied on the debugfs
  changes.

  Everything has been in linux-next for a while"

* tag 'driver-core-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (324 commits)
  Revert "ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries"
  fs: debugfs: add forward declaration for struct device type
  firmware class: Deletion of an unnecessary check before the function call "vunmap"
  firmware loader: fix hung task warning dump
  devcoredump: provide a one-way disable function
  device: Add dev_<level>_once variants
  ath: ath9k: use debugfs_create_devm_seqfile() helper for seq_file entries
  ath: use seq_file api for ath9k debugfs files
  debugfs: add helper function to create device related seq_file
  drivers/base: cacheinfo: remove noisy error boot message
  Revert "core: platform: add warning if driver has no owner"
  drivers: base: support cpu cache information interface to userspace via sysfs
  drivers: base: add cpu_device_create to support per-cpu devices
  topology: replace custom attribute macros with standard DEVICE_ATTR*
  cpumask: factor out show_cpumap into separate helper function
  driver core: Fix unbalanced device reference in drivers_probe
  driver core: fix race with userland in device_add()
  sysfs/kernfs: make read requests on pre-alloc files use the buffer.
  sysfs/kernfs: allow attributes to request write buffer be pre-allocated.
  fs: sysfs: return EGBIG on write if offset is larger than file size
  ...
2014-12-14 16:10:09 -08:00
Robert Baldyga 57850a50c1 serial: samsung: use port->fifosize instead of hardcoded values
Hardcoded FIFO size can cause hardware performance limitation.
Using real size value provides better FIFO usage.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-25 17:06:40 -08:00
Robert Baldyga 2f1ba72d23 serial: samsung: prefer to use fifosize from driver data
If we have fifosize set in driver data we prefer to use it instead of default
fifosize value (which is always 16). If there is defined fifosize for particular
serial we prefer to use it, otherwise we use value from info, which is
common for all serials on given platform.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-25 17:06:40 -08:00
Robert Baldyga ef4aca7048 serial: samsung: fix style problems
Split lines longer than 80 chars and remove unnecessary whitespaces.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-25 17:06:39 -08:00
Robert Baldyga 1ff383a4c3 serial: samsung: wait for transfer completion before clock disable
This patch adds waiting until transmit buffer and shifter will be empty
before clock disabling.

Without this fix it's possible to have clock disabled while data was
not transmited yet, which causes unproper state of TX line and problems
in following data transfers.

Cc: <stable@vger.kernel.org> # v2.6.26+
Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-25 17:06:39 -08:00
Paul Bolle 510d483285 serial: samsung: Remove checks for CONFIG_SAMSUNG_CLOCK
Commit 32726d2d55 ("ARM: SAMSUNG: Remove legacy clock code") removed
the Kconfig symbol SAMSUNG_CLOCK. Remove the last checks for its macro,
and the dead code they hide, too.

Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-05 19:22:09 -08:00
Wolfram Sang 9144b3cded tty: serial: drop owner assignment from platform_drivers
A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-10-20 16:21:45 +02:00
Linus Torvalds b3345d7c57 ARM: SoC platform changes for 3.17
This is the bulk of new SoC enablement and other platform changes for 3.17:
 
 * Samsung S5PV210 has been converted to DT and multiplatform
 * Clock drivers and bindings for some of the lower-end i.MX 1/2 platforms
 * Kirkwood, one of the popular Marvell platforms, is folded into the
   mvebu platform code, removing mach-kirkwood.
 * Hwmod data for TI AM43xx and DRA7 platforms.
 * More additions of Renesas shmobile platform support
 * Removal of plat-samsung contents that can be removed with S5PV210 being
   multiplatform/DT-enabled and the other two old platforms being removed.
 
 New platforms (most with only basic support right now):
 
 * Hisilicon X5HD2 settop box chipset is introduced
 * Mediatek MT6589 (mobile chipset) is introduced
 * Broadcom BCM7xxx settop box chipset is introduced
 
 + as usual a lot other pieces all over the platform code.
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Merge tag 'soc-for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM SoC platform changes from Olof Johansson:
 "This is the bulk of new SoC enablement and other platform changes for
  3.17:

   - Samsung S5PV210 has been converted to DT and multiplatform
   - Clock drivers and bindings for some of the lower-end i.MX 1/2
     platforms
   - Kirkwood, one of the popular Marvell platforms, is folded into the
     mvebu platform code, removing mach-kirkwood
   - Hwmod data for TI AM43xx and DRA7 platforms
   - More additions of Renesas shmobile platform support
   - Removal of plat-samsung contents that can be removed with S5PV210
     being multiplatform/DT-enabled and the other two old platforms
     being removed

  New platforms (most with only basic support right now):

   - Hisilicon X5HD2 settop box chipset is introduced
   - Mediatek MT6589 (mobile chipset) is introduced
   - Broadcom BCM7xxx settop box chipset is introduced

  + as usual a lot other pieces all over the platform code"

* tag 'soc-for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (240 commits)
  ARM: hisi: remove smp from machine descriptor
  power: reset: move hisilicon reboot code
  ARM: dts: Add hix5hd2-dkb dts file.
  ARM: debug: Rename Hi3716 to HIX5HD2
  ARM: hisi: enable hix5hd2 SoC
  ARM: hisi: add ARCH_HISI
  MAINTAINERS: add entry for Broadcom ARM STB architecture
  ARM: brcmstb: select GISB arbiter and interrupt drivers
  ARM: brcmstb: add infrastructure for ARM-based Broadcom STB SoCs
  ARM: configs: enable SMP in bcm_defconfig
  ARM: add SMP support for Broadcom mobile SoCs
  Documentation: arm: misc updates to Marvell EBU SoC status
  Documentation: arm: add URLs to public datasheets for the Marvell Armada XP SoC
  ARM: mvebu: fix build without platforms selected
  ARM: mvebu: add cpuidle support for Armada 38x
  ARM: mvebu: add cpuidle support for Armada 370
  cpuidle: mvebu: add Armada 38x support
  cpuidle: mvebu: add Armada 370 support
  cpuidle: mvebu: rename the driver from armada-370-xp to mvebu-v7
  ARM: mvebu: export the SCU address
  ...
2014-08-08 11:14:29 -07:00
Tomasz Figa f73d4cb681 serial: samsung: Remove support for legacy clock code
All Samsung platforms are now using the Common Clock Framework and the
legacy clock code is being removed, so remove related dead code from
samsung-serial driver as well.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
2014-07-19 04:24:59 +09:00
Naveen Krishna Chatradhi 4622eb6873 serial: samsung: improve code clarity by defining a variable
The of_node is derived from pdev for every usage, define a
device_node variable instead.

Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17 18:18:22 -07:00
Naveen Krishna Chatradhi 3bcce591aa serial: samsung: correct the case and default order in switch
The cases should comes before default in a switch.

Even if we want the case and default to share same code.
Its good to define the case first followed by default.

Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17 18:18:22 -07:00
Naveen Krishna Chatradhi 135f07c325 serial: samsung: get fifosize via device tree
UART modules on some SoCs only differ in the fifosize of each
UART channel. Its useless to duplicate the drv_data structure
or create a compatible name for such a change.

We can get fifosize via the device tree nodes (not mandating it).

Also updates the documentation.

Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-17 18:18:22 -07:00
Fabio Estevam 1ff5b64dcc serial: samsung: Use %pa to print 'resource_size_t' type
When building multi_v7_defconfig with CONFIG_ARM_LPAE=y the following warning
is seen:

drivers/tty/serial/samsung.c: In function 's3c24xx_serial_init_port':
drivers/tty/serial/samsung.c:1229:2: warning: format '%x' expects argument of type 'unsigned int', but argument 2 has type 'resource_size_t' [-Wformat]

Use %pa to print 'resource_size_t' type to fix the warning.

Reported-by: Olof's autobuilder <build@lixom.net>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Reviewed-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-10 15:27:37 -07:00
Alexander Shiyan 8b152f1096 serial: treewide: Remove empty implementations of enable_ms()
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-09 17:29:38 -07:00
Kukjin Kim 953b53a71b serial: samsung: no more support for S5PC100 SoC
This patch removes s5pc100 related serial.

Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-09 17:23:28 -07:00
Kukjin Kim 1570a5386d serial: samsung: no more support for S5P6440 and S5P6450 SoCs
This patch removes s5p64x0 related serial because of removing
support for s5p64x0 SoCs.

Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-09 17:23:28 -07:00
Tomasz Figa 13a9f6c64f serial: samsung: Consider DT alias when probing ports
Current driver code relies on probe order of particular samsung-uart
instances, which makes it impossible to get proper initialization of
ports when not all ports are available on board, not even saying of
deterministic device naming.

This patch fixes this on DT-enabled systems by using DT aliases for
ports as instance ID, if specified, or falling back to legacy method
otherwise to provide backwards compatibility.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-09 17:22:55 -07:00