[PATCH v3 0/2] Register i2c adapter driver earlier and use DMA safe buffers

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Revision v3 of 3 in this series.

6 messages, 2 authors, 2018-09-11 · open the first message on its own page

[PATCH v3 0/2] Register i2c adapter driver earlier and use DMA safe buffers

From: Jun Gao <hidden>
Date: 2018-09-06 13:16:02 

This patch series based on v4.19-rc2, include i2c adapter driver register time
modification and DMA safe buffers used for i2c transactions.

changes since v2:
- Remove the patch i2c: Add helper to ease DMA handling
- Use i2c refactor function to release a DMA safe buffer

changes since v1:
- Add the initializations for DMA safe buffer pointers

Jun Gao (2):
  i2c: mediatek: Register i2c adapter driver earlier
  i2c: mediatek: Use DMA safe buffers for i2c transactions

 drivers/i2c/busses/i2c-mt65xx.c | 74 ++++++++++++++++++++++++++++++++++++-----
 1 file changed, 66 insertions(+), 8 deletions(-)

--
1.8.1.1

[PATCH v3 1/2] i2c: mediatek: Register i2c adapter driver earlier

From: Jun Gao <hidden>
Date: 2018-09-06 13:15:46 

From: Jun Gao <redacted>

In order not to block the initializations of some i2c devices.
Register i2c adapter driver at appropriate time.

Signed-off-by: Jun Gao <redacted>
---
 drivers/i2c/busses/i2c-mt65xx.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 1e57f58..806e8b90 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -888,7 +888,17 @@ static int mtk_i2c_resume(struct device *dev)
 	},
 };
 
-module_platform_driver(mtk_i2c_driver);
+static int __init mtk_i2c_adap_init(void)
+{
+	return platform_driver_register(&mtk_i2c_driver);
+}
+subsys_initcall(mtk_i2c_adap_init);
+
+static void __exit mtk_i2c_adap_exit(void)
+{
+	platform_driver_unregister(&mtk_i2c_driver);
+}
+module_exit(mtk_i2c_adap_exit);
 
 MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("MediaTek I2C Bus Driver");
-- 
1.8.1.1

Re: [PATCH v3 1/2] i2c: mediatek: Register i2c adapter driver earlier

From: Wolfram Sang <hidden>
Date: 2018-09-06 18:31:51 

On Thu, Sep 06, 2018 at 09:15:28PM +0800, Jun Gao wrote:
From: Jun Gao <redacted>

In order not to block the initializations of some i2c devices.
Register i2c adapter driver at appropriate time.

Signed-off-by: Jun Gao <redacted>
The reasons this patch was rejected in v2 still hold.

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Re: [PATCH v3 1/2] i2c: mediatek: Register i2c adapter driver earlier

From: Jun Gao <hidden>
Date: 2018-09-11 02:26:52 

On Thu, 2018-09-06 at 20:31 +0200, Wolfram Sang wrote:
On Thu, Sep 06, 2018 at 09:15:28PM +0800, Jun Gao wrote:
quoted
From: Jun Gao <redacted>

In order not to block the initializations of some i2c devices.
Register i2c adapter driver at appropriate time.

Signed-off-by: Jun Gao <redacted>
The reasons this patch was rejected in v2 still hold.
OK. Thanks for your opinion.

[PATCH v3 2/2] i2c: mediatek: Use DMA safe buffers for i2c transactions

From: Jun Gao <hidden>
Date: 2018-09-06 13:15:49 

From: Jun Gao <redacted>

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 <redacted>
---
 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..695a2ae 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_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);
@@ -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_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);
@@ -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_put_dma_safe_msg_buf(dma_wr_buf, msgs, false);
+
 			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,
 					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) {
-- 
1.8.1.1

Re: [PATCH v3 2/2] i2c: mediatek: Use DMA safe buffers for i2c transactions

From: Wolfram Sang <hidden>
Date: 2018-09-06 18:33:53 

On Thu, Sep 06, 2018 at 09:15:29PM +0800, Jun Gao wrote:
From: Jun Gao <redacted>

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 <redacted>
Applied to for-next, thanks!

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