From: Lothar Waßmann <LW@KARO-electronics.de>
Date: Wed, 10 Jan 2018 14:19:40 +0000 (+0100)
Subject: karo: add workaround for Linux hang on i.MX6QP when tzasc1_ipg_clock is disabled
X-Git-Tag: KARO-TX6-2019-07-31~19
X-Git-Url: https://git.kernelconcepts.de/?p=karo-tx-uboot.git;a=commitdiff_plain;h=ae60a91421744ef95d81cb09ea8a4fba851789c5

karo: add workaround for Linux hang on i.MX6QP when tzasc1_ipg_clock is disabled

The IPU on i.MX6QP apparently requires the tzasc1_ipg_clock
(CCGR2[11]) to be enabled which is not documented anywhere.

Enable this clock in the DCD to prevent Linux from hanging when using
the IPU.
---

diff --git a/board/karo/tx6/lowlevel_init.S b/board/karo/tx6/lowlevel_init.S
index 049d99ba64..c70dbbe7c5 100644
--- a/board/karo/tx6/lowlevel_init.S
+++ b/board/karo/tx6/lowlevel_init.S
@@ -794,13 +794,17 @@ dcd_hdr:
 	MXC_DCD_ITEM(CCM_BASE_ADDR + CCM_CCGR4, CCGR(14))
 	MXC_DCD_ITEM(CCM_BASE_ADDR + CCM_CCGR2, CCGR(7))
 	MXC_DCD_CMD_WRT(MXC_DCD_CMD_SZ_WORD, MXC_DCD_CMD_FLAG_WRITE)
-#endif
+#endif /* CONFIG_TX6_EMMC */
 	MXC_DCD_ITEM(CCM_BASE_ADDR + CCM_CHSCCDR, 0x00012093) /* default: 0x0002a150 (0x00029148) */
 	MXC_DCD_ITEM(CCM_BASE_ADDR + CCM_CSCDR2, 0x00012090) /* default: 0x0002a150 (0x00029148) */
 	MXC_DCD_ITEM(ANATOP_BASE_ADDR + ANATOP_PLL_ENET, 0x00002001) /* ENET PLL */
 
 	/* enable all relevant clocks... */
 	MXC_DCD_CMD_WRT(MXC_DCD_CMD_SZ_WORD, MXC_DCD_CMD_FLAG_SET)
+#ifdef CONFIG_TX6QP
+	/* workaround for hangup on i.MX6QP when IPU is being used */
+	MXC_DCD_ITEM(CCM_BASE_ADDR + CCM_CCGR2, CCGR(11) | CCGR(12))
+#endif
 	MXC_DCD_ITEM(CCM_BASE_ADDR + CCM_CCGR0, CCGR(2)) /* 0xf0c03f3f default: 0xf0c03f0f APBH-DMA */
 	MXC_DCD_ITEM(CCM_BASE_ADDR + CCM_CCGR1, CCGR(5)) /* 0xf0fc0c00 default: 0xf0fc0000 ENET */
 	MXC_DCD_ITEM(CCM_BASE_ADDR + CCM_CCGR2, CCGR(3)) /* 0xfc3fc0cc default: 0xfc3fc00c I2C1 */