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| author | Paul Walmsley <paul@pwsan.com> | 2012-06-21 21:40:37 -0600 |
|---|---|---|
| committer | Paul Walmsley <paul@pwsan.com> | 2012-06-21 21:40:37 -0600 |
| commit | 2acd089471d93373e051c6b1f9f9e0d9e51a76bc (patch) | |
| tree | 047f85f2990046ba33c3c0227987d70ceab50abb /drivers/w1 | |
| parent | d660030061dd7e20ad18557368188d9c1002ec71 (diff) | |
| download | linux-3.10-2acd089471d93373e051c6b1f9f9e0d9e51a76bc.tar.gz linux-3.10-2acd089471d93373e051c6b1f9f9e0d9e51a76bc.tar.bz2 linux-3.10-2acd089471d93373e051c6b1f9f9e0d9e51a76bc.zip | |
W1: OMAP HDQ1W: use 32-bit register accesses
HDQ/1-wire registers are 32 bits long, even if the register contents
fit into 8 bits, so accesses must be 32-bit aligned. Evidently the
OMAP2/3 interconnects allowed the driver to get away with 8 bit accesses,
but the OMAP4 puts a stop to that:
[ 1.488800] Driver for 1-wire Dallas network protocol.
[ 1.495025] Bad mode in data abort handler detected
[ 1.500122] Internal error: Oops - bad mode: 0 [#1] SMP
[ 1.505615] Modules linked in:
[ 1.508819] CPU: 0 Not tainted (3.3.0-rc1-00008-g45030e9 #992)
[ 1.515289] PC is at 0xffff0018
[ 1.518615] LR is at omap_hdq_probe+0xd4/0x2cc
The OMAP4430 ES2 Rev X TRM does warn about this restriction in section
23.2.6.2 "HDQ/1-Wire Registers".
Fixes the crash on OMAP4430 ES2 Pandaboard. Tested also on OMAP34xx and
OMAP2420; it seems to work fine on those chips, although due to the lack
of boards with HDQ/1-wire devices here, a more indepth test was not
possible.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Evgeniy Polyakov <zbr@ioremap.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Diffstat (limited to 'drivers/w1')
| -rw-r--r-- | drivers/w1/masters/omap_hdq.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/w1/masters/omap_hdq.c b/drivers/w1/masters/omap_hdq.c index 5ef385bfed1..344db9c5ab8 100644 --- a/drivers/w1/masters/omap_hdq.c +++ b/drivers/w1/masters/omap_hdq.c @@ -102,20 +102,20 @@ static struct w1_bus_master omap_w1_master = { /* HDQ register I/O routines */ static inline u8 hdq_reg_in(struct hdq_data *hdq_data, u32 offset) { - return __raw_readb(hdq_data->hdq_base + offset); + return __raw_readl(hdq_data->hdq_base + offset); } static inline void hdq_reg_out(struct hdq_data *hdq_data, u32 offset, u8 val) { - __raw_writeb(val, hdq_data->hdq_base + offset); + __raw_writel(val, hdq_data->hdq_base + offset); } static inline u8 hdq_reg_merge(struct hdq_data *hdq_data, u32 offset, u8 val, u8 mask) { - u8 new_val = (__raw_readb(hdq_data->hdq_base + offset) & ~mask) + u8 new_val = (__raw_readl(hdq_data->hdq_base + offset) & ~mask) | (val & mask); - __raw_writeb(new_val, hdq_data->hdq_base + offset); + __raw_writel(new_val, hdq_data->hdq_base + offset); return new_val; } |