Commit fc66b39f authored by Jun Gao's avatar Jun Gao Committed by Wolfram Sang
Browse files

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: default avatarJun Gao <jun.gao@mediatek.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 9cbeeca0

drivers/i2c/busses/i2c-mt65xx.c

+55 −7
Original line number Original line Diff line number Diff line
@@ -441,6 +441,8 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, 
	u16 control_reg;

	u16 control_reg;

	u16 restart_flag = 0;

	u16 restart_flag = 0;

	u32 reg_4g_mode;

	u32 reg_4g_mode;

	u8 *dma_rd_buf = NULL;

	u8 *dma_wr_buf = NULL;

	dma_addr_t rpaddr = 0;

	dma_addr_t rpaddr = 0;

	dma_addr_t wpaddr = 0;

	dma_addr_t wpaddr = 0;

	int ret;

	int ret;
@@ -500,10 +502,18 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, 
	if (i2c->op == I2C_MASTER_RD) {

	if (i2c->op == I2C_MASTER_RD) {

		writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG);

		writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG);

		writel(I2C_DMA_CON_RX, i2c->pdmabase + OFFSET_CON);

		writel(I2C_DMA_CON_RX, i2c->pdmabase + OFFSET_CON);

		rpaddr = dma_map_single(i2c->dev, msgs->buf,



		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);

					msgs->len, DMA_FROM_DEVICE);

		if (dma_mapping_error(i2c->dev, rpaddr))

		if (dma_mapping_error(i2c->dev, rpaddr)) {

			i2c_put_dma_safe_msg_buf(dma_rd_buf, msgs, false);



			return -ENOMEM;

			return -ENOMEM;

		}





		if (i2c->dev_comp->support_33bits) {

		if (i2c->dev_comp->support_33bits) {

			reg_4g_mode = mtk_i2c_set_4g_mode(rpaddr);

			reg_4g_mode = mtk_i2c_set_4g_mode(rpaddr);
@@ -515,10 +525,18 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, 
	} else if (i2c->op == I2C_MASTER_WR) {

	} else if (i2c->op == I2C_MASTER_WR) {

		writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG);

		writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG);

		writel(I2C_DMA_CON_TX, i2c->pdmabase + OFFSET_CON);

		writel(I2C_DMA_CON_TX, i2c->pdmabase + OFFSET_CON);

		wpaddr = dma_map_single(i2c->dev, msgs->buf,



		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);

					msgs->len, DMA_TO_DEVICE);

		if (dma_mapping_error(i2c->dev, wpaddr))

		if (dma_mapping_error(i2c->dev, wpaddr)) {

			i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, false);



			return -ENOMEM;

			return -ENOMEM;

		}





		if (i2c->dev_comp->support_33bits) {

		if (i2c->dev_comp->support_33bits) {

			reg_4g_mode = mtk_i2c_set_4g_mode(wpaddr);

			reg_4g_mode = mtk_i2c_set_4g_mode(wpaddr);
@@ -530,16 +548,39 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, 
	} else {

	} else {

		writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_INT_FLAG);

		writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_INT_FLAG);

		writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_CON);

		writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_CON);

		wpaddr = dma_map_single(i2c->dev, msgs->buf,



		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);

					msgs->len, DMA_TO_DEVICE);

		if (dma_mapping_error(i2c->dev, wpaddr))

		if (dma_mapping_error(i2c->dev, wpaddr)) {

			i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, false);



			return -ENOMEM;

			return -ENOMEM;

		rpaddr = dma_map_single(i2c->dev, (msgs + 1)->buf,

		}



		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,

					(msgs + 1)->len,

					DMA_FROM_DEVICE);

					DMA_FROM_DEVICE);

		if (dma_mapping_error(i2c->dev, rpaddr)) {

		if (dma_mapping_error(i2c->dev, rpaddr)) {

			dma_unmap_single(i2c->dev, wpaddr,

			dma_unmap_single(i2c->dev, wpaddr,

					 msgs->len, DMA_TO_DEVICE);

					 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;

			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) {

	if (i2c->op == I2C_MASTER_WR) {

		dma_unmap_single(i2c->dev, wpaddr,

		dma_unmap_single(i2c->dev, wpaddr,

				 msgs->len, DMA_TO_DEVICE);

				 msgs->len, DMA_TO_DEVICE);



		i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, true);

	} else if (i2c->op == I2C_MASTER_RD) {

	} else if (i2c->op == I2C_MASTER_RD) {

		dma_unmap_single(i2c->dev, rpaddr,

		dma_unmap_single(i2c->dev, rpaddr,

				 msgs->len, DMA_FROM_DEVICE);

				 msgs->len, DMA_FROM_DEVICE);



		i2c_put_dma_safe_msg_buf(dma_rd_buf, msgs, true);

	} else {

	} else {

		dma_unmap_single(i2c->dev, wpaddr, msgs->len,

		dma_unmap_single(i2c->dev, wpaddr, msgs->len,

				 DMA_TO_DEVICE);

				 DMA_TO_DEVICE);

		dma_unmap_single(i2c->dev, rpaddr, (msgs + 1)->len,

		dma_unmap_single(i2c->dev, rpaddr, (msgs + 1)->len,

				 DMA_FROM_DEVICE);

				 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) {

	if (ret == 0) {

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