[PATCH 4.4 032/143] clk: imx6sl: ensure MMDC CH0 handshake is bypassed

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

[ Upstream commit 0efcc2c0fd2001a83240a8c3d71f67770484917e ]

Same as other i.MX6 SoCs, ensure unused MMDC channel's
handshake is bypassed, this is to make sure no request
signal will be generated when periphe_clk_sel is changed
or SRC warm reset is triggered.

Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx>
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/clk/imx/clk-imx6sl.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/clk/imx/clk-imx6sl.c b/drivers/clk/imx/clk-imx6sl.c
index 1be6230a07af..8b6306dc5fc6 100644
--- a/drivers/clk/imx/clk-imx6sl.c
+++ b/drivers/clk/imx/clk-imx6sl.c
@@ -17,6 +17,8 @@
 
 #include "clk.h"
 
+#define CCDR				0x4
+#define BM_CCM_CCDR_MMDC_CH0_MASK	(1 << 17)
 #define CCSR			0xc
 #define BM_CCSR_PLL1_SW_CLK_SEL	(1 << 2)
 #define CACRR			0x10
@@ -414,6 +416,10 @@ static void __init imx6sl_clocks_init(struct device_node *ccm_node)
 	clks[IMX6SL_CLK_USDHC3]       = imx_clk_gate2("usdhc3",       "usdhc3_podf",       base + 0x80, 6);
 	clks[IMX6SL_CLK_USDHC4]       = imx_clk_gate2("usdhc4",       "usdhc4_podf",       base + 0x80, 8);
 
+	/* Ensure the MMDC CH0 handshake is bypassed */
+	writel_relaxed(readl_relaxed(base + CCDR) |
+		BM_CCM_CCDR_MMDC_CH0_MASK, base + CCDR);
+
 	imx_check_clocks(clks, ARRAY_SIZE(clks));
 
 	clk_data.clks = clks;
-- 
2.19.1