diff options
author | Richard Fitzgerald <rf@opensource.cirrus.com> | 2018-08-27 14:51:15 +0100 |
---|---|---|
committer | Lee Jones <lee.jones@linaro.org> | 2018-10-23 08:58:34 +0100 |
commit | b04e68d16605dcde1c21b5df5f86a5372e53ae97 (patch) | |
tree | 539c884321e9b00d65e6a1d1b52773a342ced999 | |
parent | 6b269a41a4520f7eb639e61a45ebbb9c9267d5e0 (diff) |
mfd: madera: Don't use regmap_read_poll_timeout to poll for BOOT_DONE
While polling for BOOT_DONE the chip could NAK a read because it is
still booting, which would terminate the regmap_read_poll_timeout()
with an error.
Instead implement a polling loop that ignores read errors so we
always poll until the chip signals boot or the loop times out.
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
-rw-r--r-- | drivers/mfd/madera-core.c | 33 |
1 files changed, 20 insertions, 13 deletions
diff --git a/drivers/mfd/madera-core.c b/drivers/mfd/madera-core.c index 8cfea969b060..440030cecbbd 100644 --- a/drivers/mfd/madera-core.c +++ b/drivers/mfd/madera-core.c @@ -132,32 +132,39 @@ const char *madera_name_from_type(enum madera_type type) } EXPORT_SYMBOL_GPL(madera_name_from_type); -#define MADERA_BOOT_POLL_MAX_INTERVAL_US 5000 -#define MADERA_BOOT_POLL_TIMEOUT_US 25000 +#define MADERA_BOOT_POLL_INTERVAL_USEC 5000 +#define MADERA_BOOT_POLL_TIMEOUT_USEC 25000 static int madera_wait_for_boot(struct madera *madera) { + ktime_t timeout; unsigned int val; - int ret; + int ret = 0; /* * We can't use an interrupt as we need to runtime resume to do so, * so we poll the status bit. This won't race with the interrupt * handler because it will be blocked on runtime resume. + * The chip could NAK a read request while it is booting so ignore + * errors from regmap_read. */ - ret = regmap_read_poll_timeout(madera->regmap, - MADERA_IRQ1_RAW_STATUS_1, - val, - (val & MADERA_BOOT_DONE_STS1), - MADERA_BOOT_POLL_MAX_INTERVAL_US, - MADERA_BOOT_POLL_TIMEOUT_US); - - if (ret) - dev_err(madera->dev, "Polling BOOT_DONE_STS failed: %d\n", ret); + timeout = ktime_add_us(ktime_get(), MADERA_BOOT_POLL_TIMEOUT_USEC); + regmap_read(madera->regmap, MADERA_IRQ1_RAW_STATUS_1, &val); + while (!(val & MADERA_BOOT_DONE_STS1) && + !ktime_after(ktime_get(), timeout)) { + usleep_range(MADERA_BOOT_POLL_INTERVAL_USEC / 2, + MADERA_BOOT_POLL_INTERVAL_USEC); + regmap_read(madera->regmap, MADERA_IRQ1_RAW_STATUS_1, &val); + }; + + if (!(val & MADERA_BOOT_DONE_STS1)) { + dev_err(madera->dev, "Polling BOOT_DONE_STS timed out\n"); + ret = -ETIMEDOUT; + } /* * BOOT_DONE defaults to unmasked on boot so we must ack it. - * Do this unconditionally to avoid interrupt storms. + * Do this even after a timeout to avoid interrupt storms. */ regmap_write(madera->regmap, MADERA_IRQ1_STATUS_1, MADERA_BOOT_DONE_EINT1); |