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mfd: madera: Wait for boot done before accessing any other registers

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It is advised to wait for the boot done bit to be set before reading
any other register, update the driver to respect this.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
This commit is contained in:
Charles Keepax 2020-01-06 10:28:34 +00:00 committed by Lee Jones
parent 5e2540c17f
commit 7f6d869846
1 changed files with 15 additions and 2 deletions
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17
drivers/mfd/madera-core.c
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@ -199,7 +199,7 @@ EXPORT_SYMBOL_GPL(madera_name_from_type);
#define MADERA_BOOT_POLL_INTERVAL_USEC 5000
#define MADERA_BOOT_POLL_TIMEOUT_USEC 25000
static int madera_wait_for_boot(struct madera *madera)
static int madera_wait_for_boot_noack(struct madera *madera)
{
ktime_t timeout;
unsigned int val = 0;
@ -226,6 +226,13 @@ static int madera_wait_for_boot(struct madera *madera)
ret = -ETIMEDOUT;
}
return ret;
}
static int madera_wait_for_boot(struct madera *madera)
{
int ret = madera_wait_for_boot_noack(madera);
/*
* BOOT_DONE defaults to unmasked on boot so we must ack it.
* Do this even after a timeout to avoid interrupt storms.
@ -545,6 +552,12 @@ int madera_dev_init(struct madera *madera)
regcache_cache_only(madera->regmap, false);
regcache_cache_only(madera->regmap_32bit, false);
ret = madera_wait_for_boot_noack(madera);
if (ret) {
dev_err(madera->dev, "Device failed initial boot: %d\n", ret);
goto err_reset;
}
/*
* Now we can power up and verify that this is a chip we know about
* before we start doing any writes to its registers.
@ -650,7 +663,7 @@ int madera_dev_init(struct madera *madera)
ret = madera_wait_for_boot(madera);
if (ret) {
dev_err(madera->dev, "Device failed initial boot: %d\n", ret);
dev_err(madera->dev, "Failed to clear boot done: %d\n", ret);
goto err_reset;
}