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authorBen Dooks <ben-linux@fluff.org>2007-06-23 17:16:31 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-06-24 08:59:11 -0700
commit1e27dbe7746f3bcbcf1f9a37f31df4b886e36ce3 (patch)
treecca92108cf97c5c13b0c9e7f85f11da8bd513fb5
parentffd65af0e67a054e1e2393c9b0995c03c47cdc30 (diff)
SM501: Check SM501 ID register on initialisation
When binding the driver, check the ID register for a valid identity, in case the SM501 is not functioning correctly. Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/mfd/sm501.c14
-rw-r--r--include/linux/sm501-regs.h3
2 files changed, 13 insertions, 4 deletions
diff --git a/drivers/mfd/sm501.c b/drivers/mfd/sm501.c
index e14d70e07418..8135e4c3bf47 100644
--- a/drivers/mfd/sm501.c
+++ b/drivers/mfd/sm501.c
@@ -893,6 +893,7 @@ static int sm501_init_dev(struct sm501_devdata *sm)
{
resource_size_t mem_avail;
unsigned long dramctrl;
+ unsigned long devid;
int ret;
mutex_init(&sm->clock_lock);
@@ -900,13 +901,18 @@ static int sm501_init_dev(struct sm501_devdata *sm)
INIT_LIST_HEAD(&sm->devices);
- dramctrl = readl(sm->regs + SM501_DRAM_CONTROL);
+ devid = readl(sm->regs + SM501_DEVICEID);
+ if ((devid & SM501_DEVICEID_IDMASK) != SM501_DEVICEID_SM501) {
+ dev_err(sm->dev, "incorrect device id %08lx\n", devid);
+ return -EINVAL;
+ }
+
+ dramctrl = readl(sm->regs + SM501_DRAM_CONTROL);
mem_avail = sm501_mem_local[(dramctrl >> 13) & 0x7];
- dev_info(sm->dev, "SM501 At %p: Version %08x, %ld Mb, IRQ %d\n",
- sm->regs, readl(sm->regs + SM501_DEVICEID),
- (unsigned long)mem_avail >> 20, sm->irq);
+ dev_info(sm->dev, "SM501 At %p: Version %08lx, %ld Mb, IRQ %d\n",
+ sm->regs, devid, (unsigned long)mem_avail >> 20, sm->irq);
sm501_dump_gate(sm);
diff --git a/include/linux/sm501-regs.h b/include/linux/sm501-regs.h
index 8b4ecf02f9dc..014e73b31fc0 100644
--- a/include/linux/sm501-regs.h
+++ b/include/linux/sm501-regs.h
@@ -109,6 +109,9 @@
#define SM501_DEVICEID (0x000060)
/* 0x050100A0 */
+#define SM501_DEVICEID_SM501 (0x05010000)
+#define SM501_DEVICEID_IDMASK (0xffff0000)
+
#define SM501_PLLCLOCK_COUNT (0x000064)
#define SM501_MISC_TIMING (0x000068)
#define SM501_CURRENT_SDRAM_CLOCK (0x00006C)