Reset DMA in hardware init function to avoid unknown hardware state
before do any I2C operation.
Signed-off-by: Liguo Zhang <liguo.zhang@xxxxxxxxxxxx>
Signed-off-by: Eddie Huang <eddie.huang@xxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-mt65xx.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 9920eef..055159d 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -1,6 +1,8 @@
/*
* Copyright (c) 2014 MediaTek Inc.
- * Author: Xudong Chen <xudong.chen@xxxxxxxxxxxx>
+ * Author:
+ * Xudong Chen <xudong.chen@xxxxxxxxxxxx>
+ * Liguo Zhang <liguo.zhang@xxxxxxxxxxxx>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
@@ -59,6 +61,7 @@
#define I2C_DMA_START_EN 0x0001
#define I2C_DMA_INT_FLAG_NONE 0x0000
#define I2C_DMA_CLR_FLAG 0x0000
+#define I2C_DMA_HARD_RST 0x0002
#define I2C_DEFAULT_SPEED 100000 /* hz */
#define MAX_FS_MODE_SPEED 400000
@@ -81,6 +84,7 @@ enum DMA_REGS_OFFSET {
OFFSET_INT_FLAG = 0x0,
OFFSET_INT_EN = 0x04,
OFFSET_EN = 0x08,
+ OFFSET_RST = 0x0c,
OFFSET_CON = 0x18,
OFFSET_TX_MEM_ADDR = 0x1c,
OFFSET_RX_MEM_ADDR = 0x20,
@@ -262,6 +266,10 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
I2C_CONTROL_CLK_EXT_EN | I2C_CONTROL_DMA_EN;
writew(control_reg, i2c->base + OFFSET_CONTROL);
writew(I2C_DELAY_LEN, i2c->base + OFFSET_DELAY_LEN);
+
+ writel(I2C_DMA_HARD_RST, i2c->pdmabase + OFFSET_RST);
+ udelay(50);
+ writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);
}
/*
--
1.7.9.5
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