From: Jun Gao <jun.gao@mediatek.com>
To: Wolfram Sang <wsa@the-dreams.de>
Cc: <srv_heupstream@mediatek.com>, <devicetree@vger.kernel.org>,
<linux-i2c@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>,
<linux-mediatek@lists.infradead.org>,
Jun Gao <jun.gao@mediatek.com>
Subject: [PATCH v2 3/3] i2c: mediatek: Use DMA safe buffers for i2c transactions
Date: Sat, 7 Jul 2018 17:29:55 +0800 [thread overview]
Message-ID: <1530955795-17714-4-git-send-email-jun.gao@mediatek.com> (raw)
In-Reply-To: <1530955795-17714-1-git-send-email-jun.gao@mediatek.com>
From: Jun Gao <jun.gao@mediatek.com>
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>
---
drivers/i2c/busses/i2c-mt65xx.c | 62 ++++++++++++++++++++++++++++++++++++-----
1 file changed, 55 insertions(+), 7 deletions(-)
diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 806e8b90..c92cae7 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -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;
@@ -500,10 +502,18 @@ 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,
+
+ 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))
+ if (dma_mapping_error(i2c->dev, rpaddr)) {
+ i2c_free_dma_safe_msg_buf(msgs, dma_rd_buf);
+
return -ENOMEM;
+ }
if (i2c->dev_comp->support_33bits) {
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) {
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,
+
+ 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))
+ if (dma_mapping_error(i2c->dev, wpaddr)) {
+ i2c_free_dma_safe_msg_buf(msgs, dma_wr_buf);
+
return -ENOMEM;
+ }
if (i2c->dev_comp->support_33bits) {
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 {
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,
+
+ 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))
+ if (dma_mapping_error(i2c->dev, wpaddr)) {
+ i2c_free_dma_safe_msg_buf(msgs, dma_wr_buf);
+
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_free_dma_safe_msg_buf(msgs, dma_wr_buf);
+
+ 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_free_dma_safe_msg_buf(msgs, dma_wr_buf);
+ i2c_free_dma_safe_msg_buf((msgs + 1), dma_rd_buf);
+
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_release_dma_safe_msg_buf(msgs, dma_wr_buf);
} else if (i2c->op == I2C_MASTER_RD) {
dma_unmap_single(i2c->dev, rpaddr,
msgs->len, DMA_FROM_DEVICE);
+
+ i2c_release_dma_safe_msg_buf(msgs, dma_rd_buf);
} 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_release_dma_safe_msg_buf(msgs, dma_wr_buf);
+ i2c_release_dma_safe_msg_buf((msgs + 1), dma_rd_buf);
}
if (ret == 0) {
--
1.8.1.1
prev parent reply other threads:[~2018-07-07 9:31 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-07 9:29 [PATCH v2 0/3] Register i2c adapter driver earlier and use DMA safe buffers Jun Gao
2018-07-07 9:29 ` [PATCH v2 1/3] i2c: mediatek: Register i2c adapter driver earlier Jun Gao
2018-08-08 20:40 ` Wolfram Sang
2018-07-07 9:29 ` [PATCH v2 2/3] i2c: Add helper to ease DMA handling Jun Gao
2018-07-08 11:58 ` Peter Rosin
2018-07-08 12:46 ` Peter Rosin
2018-08-08 20:57 ` Wolfram Sang
2018-08-09 9:13 ` Yingjoe Chen
2018-08-09 9:23 ` Wolfram Sang
2018-07-07 9:29 ` Jun Gao [this message]
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