receive_chars() was getting too big and too difficult
to follow. By splitting it into separate RDI and RSLI
handlers, we have smaller functions which are easy
to understand and only touch the pieces which they need
to touch.
Tested-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
quite a few changes here, though they are
pretty obvious. In summary we're making sure
to detect which interrupt type we need to
handle before calling the underlying interrupt
handling procedure.
Tested-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The driver doesn't need to know about its platform_device.
Everything the driver needs can be done through the
struct device pointer. In case we need to use the
OMAP-specific PM function pointers, those can make
sure to find the device's platform_device pointer
so they can find the struct omap_device through
pdev->archdata field.
Tested-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
this patch is in preparation to a few other changes
which will align on the prototype for function
pointers passed through pdata.
It also helps cleaning up the driver a little by
agregating checks for pdata in a single location.
Tested-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
current code only works because struct uart_port
is the first member on the uart_omap_port structure.
If, for whatever reason, someone puts another
member as the first of the structure, that cast
won't work anymore. In order to be safe, let's use
a container_of() which, for now, gets optimized into
a cast anyway.
Tested-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
OMAP hardware doesn't provide a phyisical DTR line, but
some configurations may need a DTR line which tracks whether
the device is open or not.
So allow a gpio to be configured as the DTR line.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently the errata is populated based on cpu checks this can
be removed and replaced with module version check of uart ip block.
MVR reg is provided within the uart reg map use the same
to populate the errata and thus now errata population and handling
can be managed within the driver itself.
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Kevin Hilman <khilman@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
Reviewed-by: Jon Hunter <jon-hunter@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The patch does the following
- The pm_runtime_disable is called in the remove not in the error
case of probe.The patch calls the pm_runtime_disable in the error
case.
- Calls pm_runtime_put in the error case.
- The up is not freed in the error path. Fix the memory leak by using
devm_* so that the memory need not be freed in the driver.
- Also the iounmap is not called fix the same by calling using devm_ioremap.
- Make the name of the error tags more meaningful.
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Govindraj.R <govindraj.raja@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The following commit: be4b028195
(tty: serial: OMAP: block idle while the UART is transferring data in PIO mode),
is introducing an oops if OMAP is booted using device tree blob because
the pdata will not be initialized.
Check if pdata is set before de-referencing it.
Signed-off-by: Benoit Cousson <b-cousson@ti.com>
Reviewed-by: Paul Walmsley <paul@pwsan.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The receive FIFO wakeup latency estimate in the omap-serial driver is
three orders of magnitude too small. This effectively prevents the
MPU from going to a low-power state when CONFIG_CPU_IDLE=y. This is a
major power management regression and masks some other FIFO-related
bugs in the driver.
Fix by correcting the most egregious problem in the RX wakeup latency
estimate. There are several other flaws in the estimator; these will
be fixed by a separate patch series intended for 3.4.
The difference in low-power states with this patch can be observed via
debugfs in pm_debug/count.
This estimate does not have any effect when CONFIG_CPU_IDLE=n.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Alan Cox <alan@linux.intel.com>
Acked-by: Govindraj.R <govindraj.raja@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Prevent OMAP UARTs from going idle while they are still transferring
data in PIO mode. This works around an oversight in the OMAP UART
hardware present in OMAP34xx and earlier: an idle UART won't send a
wakeup when the TX FIFO threshold is reached. This causes long delays
during data transmission when the MPU powerdomain enters a low-power
mode. The MPU interrupt controller is not able to respond to
interrupts when it's in a low-power state, so the TX buffer is not
refilled until another wakeup event occurs.
This fix changes the erratum i291 DMA idle workaround. Rather than
toggling between force-idle and no-idle, it will toggle between
smart-idle and no-idle. The important part of the workaround is the
no-idle part, so this shouldn't result in any change in behavior.
This fix should work on all OMAP UARTs. Future patches intended for
the 3.4 merge window will make this workaround conditional on a
"feature" flag, and will use the OMAP36xx+ TX event wakeup support.
Thanks to Kevin Hilman <khilman@ti.com> for mentioning the erratum i291
workaround, which led to the development of this approach.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Govindraj.R <govindraj.raja@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the (default) PIO mode, use a one-byte RX FIFO threshold. The OMAP
UART IP blocks do not appear to be capable of waking the system under
an RX timeout condition. Since the previous RX FIFO threshold was 16
bytes, this meant that omap-serial.c did not become aware of any
received data until all those bytes arrived or until another UART
interrupt occurred. This made the serial console and presumably other
serial applications (GPS, serial Bluetooth) unusable or extremely
slow. A 1-byte RX FIFO threshold also allows the MPU to enter a
low-power consumption state while waiting for the FIFO to fill.
This can be verified using the serial console by comparing the
behavior when "0123456789abcde" is pasted in from another window, with
the behavior when "0123456789abcdef" is pasted in. Since the former
string is less than sixteen bytes long, the string is not echoed for
some time, while the latter string is echoed immediately.
DMA operation is unaffected by this patch.
Thanks to Russell King - ARM Linux <linux@arm.linux.org.uk> for some
additional information on the standard behavior of the RX timeout
event, which was used to improve this commit description.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Govindraj Raja <govindraj.r@ti.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Russell King <linux@arm.linux.org.uk>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It seems that when the transmit FIFO threshold is reached on OMAP
UARTs, it does not result in a PRCM wakeup. This appears to be a
silicon bug. This means that if the MPU powerdomain is in a low-power
state, the MPU will not be awakened to refill the FIFO until the next
interrupt from another device.
The best solution, at least for the short term, would be for the OMAP
serial driver to call a OMAP subarchitecture function to prevent the
MPU powerdomain from entering a low power state while the FIFO has
data to transmit. However, we no longer have a clean way to do this,
since patches that add platform_data function pointers have been
deprecated by the OMAP maintainer. So we attempt to work around this
as well. The workarounds depend on the setting of CONFIG_CPU_IDLE.
When CONFIG_CPU_IDLE=n, the driver will now only transmit one byte at
a time. This causes the transmit FIFO threshold interrupt to stay
active until there is no more data to be sent. Thus, the MPU
powerdomain stays on during transmits. Aside from that energy
consumption penalty, each transmitted byte results in a huge number of
UART interrupts -- about five per byte. This wastes CPU time and is
quite inefficient, but is probably the most expedient workaround in
this case.
When CONFIG_CPU_IDLE=y, there is a slightly more direct workaround:
the PM QoS constraint can be abused to keep the MPU powerdomain on.
This results in a normal number of interrupts, but, similar to the
above workaround, wastes power by preventing the MPU from entering
WFI.
Future patches are planned for the 3.4 merge window to implement more
efficient, but also more disruptive, workarounds to these problems.
DMA operation is unaffected by this patch.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Govindraj Raja <govindraj.r@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Ensure FIFO levels are set correctly in non-DMA mode (the default).
This patch will cause a receive FIFO threshold interrupt to be raised when
there is at least one byte in the RX FIFO. It will also cause a transmit
FIFO threshold interrupt when there is only one byte remaining in the TX
FIFO.
These changes fix the receive interrupt problem and part of the
transmit interrupt problem. A separate set of issues must be worked
around for the transmit path to have a basic level of functionality; a
subsequent patch will address these.
DMA operation is unaffected by this patch.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Govindraj Raja <govindraj.r@ti.com>
Cc: Kevin Hilman <khilman@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The function serial_omap_restore_context is called only from
serial_omap_runtime_resume which depends on CONFIG_PM_RUNTIME. Make
serial_omap_restore_context also compile conditionally.
if CONFIG_PM_RUNTIME is not defined below warn may be seen.
LD net/xfrm/built-in.o
drivers/tty/serial/omap-serial.c:1524: warning: 'serial_omap_restore_context' defined but not used
CC drivers/tty/vt/selection.o
Acked-by: Govindraj.R <govindraj.raja@ti.com>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The macro SET_SYSTEM_SLEEP_PM_OPS depends CONFIG_PM_SLEEP. The patch
defines the suspend and resume functions for CONFIG_PM_SLEEP instead of
CONFIG_SUSPEND.
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
power management changes for omap and imx
A significant part of the changes for these two platforms went into
power management, so they are split out into a separate branch.
* tag 'pm' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (65 commits)
ARM: imx6: remove __CPUINIT annotation from v7_invalidate_l1
ARM: imx6: fix v7_invalidate_l1 by adding I-Cache invalidation
ARM: imx6q: resume PL310 only when CACHE_L2X0 defined
ARM: imx6q: build pm code only when CONFIG_PM selected
ARM: mx5: use generic irq chip pm interface for pm functions on
ARM: omap: pass minimal SoC/board data for UART from dt
arm/dts: Add minimal device tree support for omap2420 and omap2430
omap-serial: Add minimal device tree support
omap-serial: Use default clock speed (48Mhz) if not specified
omap-serial: Get rid of all pdev->id usage
ARM: OMAP2+: hwmod: Add a new flag to handle hwmods left enabled at init
ARM: OMAP4: PRM: use PRCM interrupt handler
ARM: OMAP3: pm: use prcm chain handler
ARM: OMAP: hwmod: add support for selecting mpu_irq for each wakeup pad
ARM: OMAP2+: mux: add support for PAD wakeup interrupts
ARM: OMAP: PRCM: add suspend prepare / finish support
ARM: OMAP: PRCM: add support for chain interrupt handler
ARM: OMAP3/4: PRM: add functions to read pending IRQs, PRM barrier
ARM: OMAP2+: hwmod: Add API to enable IO ring wakeup
ARM: OMAP2+: mux: add wakeup-capable hwmod mux entries to dynamic list
...
Adapt the driver to device tree and pass minimal platform
data from device tree needed for console boot.
No power management features will be suppported for now
since it requires more tweaks around OCP settings
to toggle forceidle/noidle/smartidle bits and handling
remote wakeup and dynamic muxing.
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Reviewed-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Use a default clock speed of 48Mhz, instead of ending up with 0,
if platforms fail to specify a valid clock speed.
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Reviewed-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
With Device tree, pdev->id would no longer be Valid.
Hence get rid of all instances of its usage in the
driver. Device tree support for the driver is added
in subsequent patches.
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Reviewed-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Fixes below compilation warning.
drivers/tty/serial/omap-serial.c: In function 'serial_omap_irq':
drivers/tty/serial/omap-serial.c:228:29: warning: 'ch' may be used uninitialized in this function [-Wuninitialized]
Fix below sparse warning.
drivers/tty/serial/omap-serial.c:392:52: warning: incorrect type in argument 2 (different signedness)
drivers/tty/serial/omap-serial.c:392:52: expected int *status
drivers/tty/serial/omap-serial.c:392:52: got unsigned int *<noident>
Reported-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Govindraj.R <govindraj.raja@ti.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de> (for drivers/tty changes)
Signed-off-by: Kevin Hilman <khilman@ti.com>
Felipe Balbi
NeilBrown
Greg Kroah-Hartman
Govindraj.R
Shubhrajyoti D
Cousson, Benoit
Paul Walmsley
Greg Kroah-Hartman
Linus Torvalds
Rajendra Nayak