From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH V4 03-1/13] DMA: PL330: Support DMA_SLAVE_CONFIG command
Date: Thu, 21 Jul 2011 09:11:38 +0100 [thread overview]
Message-ID: <20110721081138.GL26574@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <CABb+yY2_XKyCr2mEzqd0bCYJk3U7+sg8Xz4b4ma2KB1BconYOw@mail.gmail.com>
On Thu, Jul 21, 2011 at 12:47:49AM +0530, Jassi Brar wrote:
> On Wed, Jul 20, 2011 at 4:16 PM, Boojin Kim <boojin.kim@samsung.com> wrote:
> > + ? ? ? ? ? ? ? if (slave_config->direction == DMA_TO_DEVICE) {
> > + ? ? ? ? ? ? ? ? ? ? ? if (slave_config->dst_addr)
> > + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? peri->fifo_addr = slave_config->dst_addr;
> > + ? ? ? ? ? ? ? ? ? ? ? if (slave_config->dst_addr_width)
> > + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? peri->burst_sz = __ffs(slave_config->dst_addr_width);
> > + ? ? ? ? ? ? ? } else if (slave_config->direction == DMA_FROM_DEVICE) {
> > + ? ? ? ? ? ? ? ? ? ? ? if (slave_config->src_addr)
> > + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? peri->fifo_addr = slave_config->src_addr;
> > + ? ? ? ? ? ? ? ? ? ? ? if (slave_config->src_addr_width)
> > + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? peri->burst_sz = __ffs(slave_config->src_addr_width);
> > + ? ? ? ? ? ? ? }
> PL330 has fixed channels to peripherals.
> So FIFO addresses(burst_sz too?) should already be set via platform data.
> Client drivers shouldn't bother.
That's utter crap, and isn't what the DMA engine API is about.
The above looks correctly implemented. Slave DMA engine users are
supposed to supply the device DMA register address via this
DMA_SLAVE_CONFIG call. Doing this via platform data for the DMA
device is braindead.
next prev parent reply other threads:[~2011-07-21 8:11 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-20 10:46 [PATCH V4 00/13] To use DMA generic APIs for Samsung DMA Boojin Kim
2011-07-20 10:46 ` [PATCH V4 01/13] DMA: PL330: Add support runtime PM for PL330 DMAC Boojin Kim
2011-07-20 18:35 ` Jassi Brar
2011-07-20 10:46 ` [PATCH V4 03-1/13] DMA: PL330: Support DMA_SLAVE_CONFIG command Boojin Kim
2011-07-20 19:17 ` Jassi Brar
2011-07-21 4:13 ` Boojin Kim
2011-07-21 5:00 ` Jassi Brar
2011-07-21 6:34 ` Boojin Kim
2011-07-21 7:31 ` Jassi Brar
2011-07-21 8:11 ` Russell King - ARM Linux [this message]
2011-07-21 9:14 ` Jassi Brar
2011-07-21 10:23 ` Linus Walleij
2011-07-21 14:28 ` Jassi Brar
2011-07-21 15:28 ` Russell King - ARM Linux
2011-07-22 13:59 ` Linus Walleij
2011-07-21 11:29 ` Russell King - ARM Linux
2011-07-21 15:12 ` Jassi Brar
2011-07-21 15:23 ` Russell King - ARM Linux
2011-07-21 15:56 ` Jassi Brar
2011-07-21 16:02 ` Russell King - ARM Linux
2011-07-22 5:42 ` Jassi Brar
2011-07-25 2:10 ` Boojin Kim
2011-07-20 10:46 ` [PATCH V4 03-2/13] DMA: PL330: Add DMA_CYCLIC capability Boojin Kim
2011-07-20 10:46 ` [PATCH V4 05/13] ARM: SAMSUNG: Add common DMA operations Boojin Kim
2011-07-20 16:04 ` [PATCH V4 00/13] To use DMA generic APIs for Samsung DMA Kukjin Kim
2011-07-22 12:07 ` Koul, Vinod
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