[PATCH 1/6] km: qrio: fix set_gpio read/modify/write

[Holger Brunck]

From: Tomas Alvarez Vanoli <tomas.alvarez-vanoli at hitachienergy.com>

Setting GPIO by reading the value of the GPRT register, toggling the
correct bit and then writing it causes input values to transfer to the
output. Here's how (example):

1) set gpio 17 and 18 as input.
2) set gpio 17 output value to 0 (read gprt, change 17 to 0, write).
3) set gpio 18 output value to 0 (read gprt, change 18 to 0, write).

The problem here is that because we set 17 as input, and it's a pull-up,
when we read gprt in step 3, the bit 17 will be 1 and not 0.
Instead of doing read/write/modify, the solution is to keep track
internally of the user set GPIOs, and replace the read step with this
static variable.

Signed-off-by: Tomas Alvarez Vanoli <tomas.alvarez-vanoli at hitachienergy.com>
Signed-off-by: Holger Brunck <holger.brunck at hitachienergy.com>
---
 board/keymile/common/qrio.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/board/keymile/common/qrio.c b/board/keymile/common/qrio.c
index c8299483299..f8f8d5edede 100644
--- a/board/keymile/common/qrio.c
+++ b/board/keymile/common/qrio.c
@@ -18,6 +18,11 @@
 #define DIRECT_OFF		0x18
 #define GPRT_OFF		0x1c
 
+// used to keep track of the user settings for the input/output
+static u32 gprt_user[2] = { 0x0, 0x0 };
+// convert the bank offset to the correct static user gprt
+#define QRIO_USER_GRPT_BANK(bank) gprt_user[(bank - 0x40) / 0x20]
+
 void show_qrio(void)
 {
 	void __iomem *qrio_base = (void *)CFG_SYS_QRIO_BASE;
@@ -72,12 +77,13 @@ void qrio_set_gpio(u8 port_off, u8 gpio_nr, bool value)
 
 	mask = 1U << gpio_nr;
 
-	gprt = in_be32(qrio_base + port_off + GPRT_OFF);
+	gprt = QRIO_USER_GRPT_BANK(port_off);
 	if (value)
 		gprt |= mask;
 	else
 		gprt &= ~mask;
 
+	QRIO_USER_GRPT_BANK(port_off) = gprt;
 	out_be32(qrio_base + port_off + GPRT_OFF, gprt);
 }
 
-- 
2.49.0