Hello.
Atsushi Nemoto wrote:
+static void tx4939ide_dma_host_set(ide_drive_t *drive, int on)
+{
+ ide_hwif_t *hwif = HWIF(drive);
+ u8 unit = drive->dn & 1;
+ unsigned long base = TX4939IDE_BASE(hwif);
+ u8 dma_stat = TX4939IDE_readb(base, DMA_stat);
+
+ if (on)
+ dma_stat |= (1 << (5 + unit));
+ else
+ dma_stat &= ~(1 << (5 + unit));
+
+ TX4939IDE_writeb(dma_stat, base, DMA_stat);
+}
BTW, you could save on using ide_dma_host_set() in LE mode if you'd
set hwif->dma_base properly...
Yes. I like endian-free approach in general, but there is already
some ifdefs in this driver. I have no strong opinion here.
Unfortunately, the way SFF-8038i registers were implemented in TX4939
necessiates BE specific #ifdef'ery. Or at least the run-time endianness
detection and passing the right struct *_ops to the IDE core -- but that would
burden the driver with unused and/or unneeded code for the opposite endiannes.
It could've been somewhat easied by the use of hwif->dma_{command|status},
etc. but those were recently removed (then again, if the DMA engine is not
SFF-8038i compatible, those fields make little sense)...
+static int __tx4939ide_dma_setup(ide_drive_t *drive)
+{
+ ide_hwif_t *hwif = drive->hwif;
+ struct request *rq = HWGROUP(drive)->rq;
+ unsigned int reading;
+ u8 dma_stat;
+ unsigned long base = TX4939IDE_BASE(hwif);
+
[...]
+
+ /* read DMA status for INTR & ERROR flags */
+ dma_stat = TX4939IDE_readb(base, DMA_stat);
+
+ /* clear INTR & ERROR flags */
+ TX4939IDE_writeb(dma_stat | 6, base, DMA_stat);
+ /* recover intmask cleared by writing to bit2 of DMA_stat */
+ TX4939IDE_writew(TX4939IDE_IGNORE_INTS << 8, base, int_ctl);
I think it might be worth factoring the BMDMA status clearing code
into a separate function...
...along with the int_ctl write, of course.
OK. Good idea.
+#ifdef __BIG_ENDIAN
+/* custom iops (independent from SWAP_IO_SPACE) */
+static u8 mm_inb(unsigned long port)
+{
+ return (u8)readb((void __iomem *)port);
+}
+static void mm_outb(u8 value, unsigned long port)
+{
+ writeb(value, (void __iomem *)port);
+}
I'm not sure readb()/writeb() are good substitute for
__raw_readb()/__raw_writeb() as __swizzle_addr_b() might be actually
changing the address...
__swizzle_addr_b() used for both readb() and __raw_readb(). ioswabb()
Ah, I missed that. :-/
More's the reason to rely on the default methods where possible.
---
Atsushi Nemoto
MBR, Sergei
