Add a req_running field to the pl330_thread to track which request (if
any) has been submitted to the DMA. This mechanism replaces the old
one in which we tried to guess the same by looking at the PC of the
DMA, which could prevent the driver from sending more requests if it
didn't guess correctly.
Reference: <1323631637-9610-1-git-send-email-javi.merino@arm.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Acked-by: Jassi Brar <jaswinder.singh@linaro.org>
Tested-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
scctl should be shifted by CC_SRCCTRL_SHFT and dcctl by
CC_DSTCCTRL_SHFT, not the other way round.
Reference: <1320244259-10496-4-git-send-email-javi.merino@arm.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Acked-by: Jassi Brar <jassisinghbrar@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When the manager is running non-secure, the only channels that can
issue interrupts are the ones that have a 1 in their corresponding bit
in Configuration Register 3. The other ones will generate an abort
when trying to signal the end of the transaction so they are useless
in non-secure mode.
Reference: <1320244259-10496-2-git-send-email-javi.merino@arm.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Acked-by: Jassi Brar <jassisinghbrar@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
If two requests have been submitted and one of them is running, if you
call pl330_chan_ctrl(ch_id, PL330_OP_START), there's a window of time
between the spin_lock_irqsave() and the _state() check in which the
running transaction may finish. In that case, we don't receive the
interrupt (because they are disabled), but _start() sees that the DMA
is stopped, so it starts it. The problem is that it sends the
transaction that has just finished again, because pl330_update()
hasn't mark it as done yet.
This patch fixes this race condition by not calling _start() if the
DMA is already executing transactions. When interrupts are reenabled,
pl330_update() will call _start().
Reference: <1317892206-3600-1-git-send-email-javi.merino@arm.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
Acked-by: Jassi Brar <jassi.brar@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The driver can handle different revisions of the core
which vary only minorly.
Signed-off-by: Jassi Brar <jassi.brar@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
PL330 is a configurable DMA controller PrimeCell device.
The register map of the device is well defined.
The configuration of a particular implementation can be
read from the six configuration registers CR0-4,Dn.
This patch implements a driver for the specification:-
http://infocenter.arm.com/help/topic/com.arm.doc.ddi0424a/DDI0424A_dmac_pl330_r0p0_trm.pdf
The exported interface should be sufficient to implement
a driver for any DMA API.
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
