[PATCH 5.10 064/103] i2c: mediatek: Fix apdma and i2c hand-shake timeout

Greg Kroah-Hartman
2021-01-15T12:43:24Z

From: Qii Wang <qii.wang@mediatek.com>

commit 05f6f7271a38c482c5021967433f7b698e102c45 upstream.

With the apdma remove hand-shake signal, it requirs special
operation timing to reset i2c manually, otherwise the interrupt
will not be triggered, i2c transmission will be timeout.

Fixes: 8426fe70cfa4("i2c: mediatek: Add apdma sync in i2c driver")
Signed-off-by: Qii Wang <qii.wang@mediatek.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/i2c/busses/i2c-mt65xx.c | 27 ++++++++++++++++++++++-----
1 file changed, 22 insertions(+), 5 deletions(-)

--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -38,6 +38,7 @@
#define I2C_IO_CONFIG_OPEN_DRAIN 0x0003
#define I2C_IO_CONFIG_PUSH_PULL 0x0000
#define I2C_SOFT_RST 0x0001
+#define I2C_HANDSHAKE_RST 0x0020
#define I2C_FIFO_ADDR_CLR 0x0001
#define I2C_DELAY_LEN 0x0002
#define I2C_TIME_CLR_VALUE 0x0000
@@ -45,6 +46,7 @@
#define I2C_WRRD_TRANAC_VALUE 0x0002
#define I2C_RD_TRANAC_VALUE 0x0001
#define I2C_SCL_MIS_COMP_VALUE 0x0000
+#define I2C_CHN_CLR_FLAG 0x0000

#define I2C_DMA_CON_TX 0x0000
#define I2C_DMA_CON_RX 0x0001
@@ -54,7 +56,9 @@
#define I2C_DMA_START_EN 0x0001
#define I2C_DMA_INT_FLAG_NONE 0x0000
#define I2C_DMA_CLR_FLAG 0x0000
+#define I2C_DMA_WARM_RST 0x0001
#define I2C_DMA_HARD_RST 0x0002
+#define I2C_DMA_HANDSHAKE_RST 0x0004

#define MAX_SAMPLE_CNT_DIV 8
#define MAX_STEP_CNT_DIV 64
@@ -475,11 +479,24 @@ static void mtk_i2c_init_hw(struct mtk_i
{
u16 control_reg;

- writel(I2C_DMA_HARD_RST, i2c->pdmabase + OFFSET_RST);
- udelay(50);
- writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);
-
- mtk_i2c_writew(i2c, I2C_SOFT_RST, OFFSET_SOFTRESET);
+ if (i2c->dev_comp->dma_sync) {
+ writel(I2C_DMA_WARM_RST, i2c->pdmabase + OFFSET_RST);
+ udelay(10);
+ writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);
+ udelay(10);
+ writel(I2C_DMA_HANDSHAKE_RST | I2C_DMA_HARD_RST,
+ i2c->pdmabase + OFFSET_RST);
+ mtk_i2c_writew(i2c, I2C_HANDSHAKE_RST | I2C_SOFT_RST,
+ OFFSET_SOFTRESET);
+ udelay(10);
+ writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);
+ mtk_i2c_writew(i2c, I2C_CHN_CLR_FLAG, OFFSET_SOFTRESET);
+ } else {
+ writel(I2C_DMA_HARD_RST, i2c->pdmabase + OFFSET_RST);
+ udelay(50);
+ writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);
+ mtk_i2c_writew(i2c, I2C_SOFT_RST, OFFSET_SOFTRESET);
+ }

/* Set ioconfig */
if (i2c->use_push_pull)