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authorEddie Huang <eddie.huang@mediatek.com>2015-08-06 15:22:10 +0800
committerWolfram Sang <wsa@the-dreams.de>2015-08-11 16:53:11 +0200
commitea89ef1f7bf7c71b4f533a6ffb3f6f124890b37b (patch)
tree2ed339ad06320608a89ee8f2e58fa29b51d05fd9 /drivers/i2c
parent66621f96c95175cc64d91dd213781bf65bbf8ec4 (diff)
downloadlinux-ea89ef1f7bf7c71b4f533a6ffb3f6f124890b37b.tar.bz2
i2c: mediatek: Reset DMA engine in hardware init function
Reset DMA in hardware init function to avoid unknown hardware state before do any I2C operation. Signed-off-by: Liguo Zhang <liguo.zhang@mediatek.com> Signed-off-by: Eddie Huang <eddie.huang@mediatek.com> Reviewed-by: Daniel Kurtz <djkurtz@chromium.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-mt65xx.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 9920eef74672..e28ad4c17d3d 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -59,6 +59,7 @@
#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 +82,7 @@ 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 +264,10 @@ 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);
}
/*