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Subject[PATCH v2 4/4] ARM: amba: Properly handle devices with power domains
Date
To read pid/cid registers, the probed device need to be properly turned on.
When it is inside a power domain, the bus code should ensure that the
given power domain is enabled before trying to access device's registers.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
---
drivers/amba/bus.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c
index 72ebf9b..4fc1976 100644
--- a/drivers/amba/bus.c
+++ b/drivers/amba/bus.c
@@ -364,6 +364,10 @@ static int read_periphid(struct amba_device *d, unsigned int *periphid)
if (!tmp)
return -ENOMEM;

+ ret = dev_pm_domain_attach(&d->dev, true);
+ if (ret == -EPROBE_DEFER)
+ goto err_unmap;
+
ret = amba_get_enable_pclk(d);
if (ret == 0) {
u32 pid, cid;
@@ -388,6 +392,8 @@ static int read_periphid(struct amba_device *d, unsigned int *periphid)
ret = -ENODEV;
}

+ dev_pm_domain_detach(&d->dev, true);
+err_unmap:
iounmap(tmp);

return ret;
--
1.9.2


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