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i2c: mediatek: Use DMA safe buffers for i2c transactions 

DMA mode will always be used in i2c transactions, try to allocate
a DMA safe buffer if the buf of struct i2c_msg used is not DMA safe.

Signed-off-by: Jun Gao <jun.gao@mediatek.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Jun Gao 2018-09-06 21:15:29 +08:00 committed by Wolfram Sang
parent 9cbeeca050
commit fc66b39fe3
1 changed files with 58 additions and 10 deletions
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68
drivers/i2c/busses/i2c-mt65xx.c
View File

@ -441,6 +441,8 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
u16 control_reg;
u16 restart_flag = 0;
u32 reg_4g_mode;
u8 *dma_rd_buf = NULL;
u8 *dma_wr_buf = NULL;
dma_addr_t rpaddr = 0;
dma_addr_t wpaddr = 0;
int ret;
@ -500,11 +502,19 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
if (i2c->op == I2C_MASTER_RD) {
writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG);
writel(I2C_DMA_CON_RX, i2c->pdmabase + OFFSET_CON);
rpaddr = dma_map_single(i2c->dev, msgs->buf,
msgs->len, DMA_FROM_DEVICE);
if (dma_mapping_error(i2c->dev, rpaddr))
dma_rd_buf = i2c_get_dma_safe_msg_buf(msgs, 0);
if (!dma_rd_buf)
return -ENOMEM;
rpaddr = dma_map_single(i2c->dev, dma_rd_buf,
msgs->len, DMA_FROM_DEVICE);
if (dma_mapping_error(i2c->dev, rpaddr)) {
i2c_put_dma_safe_msg_buf(dma_rd_buf, msgs, false);
return -ENOMEM;
}
if (i2c->dev_comp->support_33bits) {
reg_4g_mode = mtk_i2c_set_4g_mode(rpaddr);
writel(reg_4g_mode, i2c->pdmabase + OFFSET_RX_4G_MODE);
@ -515,11 +525,19 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
} else if (i2c->op == I2C_MASTER_WR) {
writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG);
writel(I2C_DMA_CON_TX, i2c->pdmabase + OFFSET_CON);
wpaddr = dma_map_single(i2c->dev, msgs->buf,
msgs->len, DMA_TO_DEVICE);
if (dma_mapping_error(i2c->dev, wpaddr))
dma_wr_buf = i2c_get_dma_safe_msg_buf(msgs, 0);
if (!dma_wr_buf)
return -ENOMEM;
wpaddr = dma_map_single(i2c->dev, dma_wr_buf,
msgs->len, DMA_TO_DEVICE);
if (dma_mapping_error(i2c->dev, wpaddr)) {
i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, false);
return -ENOMEM;
}
if (i2c->dev_comp->support_33bits) {
reg_4g_mode = mtk_i2c_set_4g_mode(wpaddr);
writel(reg_4g_mode, i2c->pdmabase + OFFSET_TX_4G_MODE);
@ -530,16 +548,39 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
} else {
writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_INT_FLAG);
writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_CON);
wpaddr = dma_map_single(i2c->dev, msgs->buf,
msgs->len, DMA_TO_DEVICE);
if (dma_mapping_error(i2c->dev, wpaddr))
dma_wr_buf = i2c_get_dma_safe_msg_buf(msgs, 0);
if (!dma_wr_buf)
return -ENOMEM;
rpaddr = dma_map_single(i2c->dev, (msgs + 1)->buf,
wpaddr = dma_map_single(i2c->dev, dma_wr_buf,
msgs->len, DMA_TO_DEVICE);
if (dma_mapping_error(i2c->dev, wpaddr)) {
i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, false);
return -ENOMEM;
}
dma_rd_buf = i2c_get_dma_safe_msg_buf((msgs + 1), 0);
if (!dma_rd_buf) {
dma_unmap_single(i2c->dev, wpaddr,
msgs->len, DMA_TO_DEVICE);
i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, false);
return -ENOMEM;
}
rpaddr = dma_map_single(i2c->dev, dma_rd_buf,
(msgs + 1)->len,
DMA_FROM_DEVICE);
if (dma_mapping_error(i2c->dev, rpaddr)) {
dma_unmap_single(i2c->dev, wpaddr,
msgs->len, DMA_TO_DEVICE);
i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, false);
i2c_put_dma_safe_msg_buf(dma_rd_buf, (msgs + 1), false);
return -ENOMEM;
}
@ -578,14 +619,21 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
if (i2c->op == I2C_MASTER_WR) {
dma_unmap_single(i2c->dev, wpaddr,
msgs->len, DMA_TO_DEVICE);
i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, true);
} else if (i2c->op == I2C_MASTER_RD) {
dma_unmap_single(i2c->dev, rpaddr,
msgs->len, DMA_FROM_DEVICE);
i2c_put_dma_safe_msg_buf(dma_rd_buf, msgs, true);
} else {
dma_unmap_single(i2c->dev, wpaddr, msgs->len,
DMA_TO_DEVICE);
dma_unmap_single(i2c->dev, rpaddr, (msgs + 1)->len,
DMA_FROM_DEVICE);
i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, true);
i2c_put_dma_safe_msg_buf(dma_rd_buf, (msgs + 1), true);
}
if (ret == 0) {