[U-Boot] [PATCH 01/17] sunxi: axp221: Protect axp221_init against multiple calls

Hans de Goede
2015-01-11T19:34:39Z

The voltage setting code knows it needs to call axp221_init before calling
the various voltage setting functions.

But users of axp utility functions like axp221_get_sid() do not know this,
so the utility functions always call axp221_init() to ensure that the
p2wi / rsb setup magic has been done.

Since doing this repeatedly is quite expensive, add a check to axp221_init
so that it only does the initialization once.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
drivers/power/axp221.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/power/axp221.c b/drivers/power/axp221.c
index 1fda19a..728727b 100644
--- a/drivers/power/axp221.c
+++ b/drivers/power/axp221.c
@@ -304,9 +304,14 @@ int axp221_set_aldo3(unsigned int mvolt)

int axp221_init(void)
{
+ /* This cannot be 0 because it is used in SPL before BSS is ready */
+ static int needs_init = 1;
u8 axp_chip_id;
int ret;

+ if (!needs_init)
+ return 0;
+
ret = pmic_bus_init();
if (ret)
return ret;
@@ -318,6 +323,7 @@ int axp221_init(void)
if (!(axp_chip_id == 0x6 || axp_chip_id == 0x7 || axp_chip_id == 0x17))
return -ENODEV;

+ needs_init = 0;
return 0;
}

--
2.1.0