[PATCH] mfd: ab8500-sysctrl: Handle probe deferral

From: Linus Walleij
Date: Fri Jan 13 2017 - 05:01:46 EST


In the current boot, clients making use of the AB8500 sysctrl
may be probed before the ab8500-sysctrl driver. This gives them
-EINVAL, but should rather give -EPROBE_DEFER.

Before this, the abx500 clock driver didn't probe properly,
and as a result the codec driver in turn using the clocks did
not probe properly. After this patch, everything probes
properly.

Also add OF compatible-string probing. This driver is all
device tree, so let's just make a drive-by-fix of that as
well.

Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
drivers/mfd/ab8500-sysctrl.c | 14 +++++++++++---
1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/mfd/ab8500-sysctrl.c b/drivers/mfd/ab8500-sysctrl.c
index 80c0efa66ac1..5b0a0850ef69 100644
--- a/drivers/mfd/ab8500-sysctrl.c
+++ b/drivers/mfd/ab8500-sysctrl.c
@@ -101,7 +101,7 @@ int ab8500_sysctrl_read(u16 reg, u8 *value)
u8 bank;

if (sysctrl_dev == NULL)
- return -EINVAL;
+ return -EPROBE_DEFER;

bank = (reg >> 8);
if (!valid_bank(bank))
@@ -117,11 +117,13 @@ int ab8500_sysctrl_write(u16 reg, u8 mask, u8 value)
u8 bank;

if (sysctrl_dev == NULL)
- return -EINVAL;
+ return -EPROBE_DEFER;

bank = (reg >> 8);
- if (!valid_bank(bank))
+ if (!valid_bank(bank)) {
+ pr_err("invalid bank\n");
return -EINVAL;
+ }

return abx500_mask_and_set_register_interruptible(sysctrl_dev, bank,
(u8)(reg & 0xFF), mask, value);
@@ -148,9 +150,15 @@ static int ab8500_sysctrl_remove(struct platform_device *pdev)
return 0;
}

+static const struct of_device_id ab8500_sysctrl_match[] = {
+ { .compatible = "stericsson,ab8500-sysctrl", },
+ {}
+};
+
static struct platform_driver ab8500_sysctrl_driver = {
.driver = {
.name = "ab8500-sysctrl",
+ .of_match_table = ab8500_sysctrl_match,
},
.probe = ab8500_sysctrl_probe,
.remove = ab8500_sysctrl_remove,
--
2.9.3