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* [PATCH V4 0/8] Introduce an attribute to choose timing setting
@ 2021-07-17 10:17 Kewei Xu
  2021-07-17 10:17 ` [PATCH v4 1/8] i2c: mediatek: fixing the incorrect register offset Kewei Xu
                   ` (7 more replies)
  0 siblings, 8 replies; 13+ messages in thread
From: Kewei Xu @ 2021-07-17 10:17 UTC (permalink / raw)
  To: wsa
  Cc: matthias.bgg, robh+dt, linux-i2c, devicetree, linux-arm-kernel,
	linux-kernel, linux-mediatek, srv_heupstream, leilk.liu,
	qii.wang, yuhan.wei, kewei.xu, ot_daolong.zhu, liguo.zhang

v4:
1. Remove the repeated assignment of the inter_clk_div parameter
2. Modify the wrong assignment of OFFSET_MULTI_DMA
3. Unify the log print format of the i2c_dump_register() and drop the extra outer parentheses
4. Place the fixes at the very least
5. Add fixed tags 25708278f810 ("i2c: mediatek: Add i2c support for MediaTek MT8183")
6. Add "i2c: mediatek: modify bus speed calculation formula"
7. Fix single line characters exceeding 80 characters
8. Combine two different series of patches.

v3:
1. Fix code errors caused by v2 modification

v2:
1. Add "dt-bindings: i2c: add attribute default-timing-adjust"
2. Split the fix into sepatate patch.

Kewei Xu (8):
  i2c: mediatek: fixing the incorrect register offset
  dt-bindings: i2c: update bindings for MT8195 SoC
  i2c: mediatek: Reset the handshake signal between i2c and dma
  i2c: mediatek: Dump i2c/dma register when a timeout occurs
  dt-bindings: i2c: add attribute default-timing-adjust
  i2c: mediatek: Add OFFSET_EXT_CONF setting back
  i2c: mediatek: Isolate speed setting via dts for special devices
  i2c: mediatek: modify bus speed calculation formula

 .../devicetree/bindings/i2c/i2c-mt65xx.txt    |   3 +
 drivers/i2c/busses/i2c-mt65xx.c               | 194 ++++++++++++++++--
 2 files changed, 180 insertions(+), 17 deletions(-)

-- 
2.18.0


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [PATCH v4 1/8] i2c: mediatek: fixing the incorrect register offset
  2021-07-17 10:17 [PATCH V4 0/8] Introduce an attribute to choose timing setting Kewei Xu
@ 2021-07-17 10:17 ` Kewei Xu
  2021-07-17 10:17 ` [PATCH v4 2/8] dt-bindings: i2c: update bindings for MT8195 SoC Kewei Xu
                   ` (6 subsequent siblings)
  7 siblings, 0 replies; 13+ messages in thread
From: Kewei Xu @ 2021-07-17 10:17 UTC (permalink / raw)
  To: wsa
  Cc: matthias.bgg, robh+dt, linux-i2c, devicetree, linux-arm-kernel,
	linux-kernel, linux-mediatek, srv_heupstream, leilk.liu,
	qii.wang, yuhan.wei, kewei.xu, ot_daolong.zhu, liguo.zhang

The reason for the modification here is that the previous
offset information is incorrect, OFFSET_DEBUGSTAT = 0xE4 is
the correct value.

Fixes: 25708278f810 ("i2c: mediatek: Add i2c support for MediaTek MT8183")
Signed-off-by: Kewei Xu <kewei.xu@mediatek.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
---
 drivers/i2c/busses/i2c-mt65xx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 5ddfa4e56ee2..222ff765e55d 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -193,7 +193,7 @@ static const u16 mt_i2c_regs_v2[] = {
 	[OFFSET_CLOCK_DIV] = 0x48,
 	[OFFSET_SOFTRESET] = 0x50,
 	[OFFSET_SCL_MIS_COMP_POINT] = 0x90,
-	[OFFSET_DEBUGSTAT] = 0xe0,
+	[OFFSET_DEBUGSTAT] = 0xe4,
 	[OFFSET_DEBUGCTRL] = 0xe8,
 	[OFFSET_FIFO_STAT] = 0xf4,
 	[OFFSET_FIFO_THRESH] = 0xf8,
-- 
2.18.0


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [PATCH v4 2/8] dt-bindings: i2c: update bindings for MT8195 SoC
  2021-07-17 10:17 [PATCH V4 0/8] Introduce an attribute to choose timing setting Kewei Xu
  2021-07-17 10:17 ` [PATCH v4 1/8] i2c: mediatek: fixing the incorrect register offset Kewei Xu
@ 2021-07-17 10:17 ` Kewei Xu
  2021-07-17 10:17 ` [PATCH v4 3/8] i2c: mediatek: Reset the handshake signal between i2c and dma Kewei Xu
                   ` (5 subsequent siblings)
  7 siblings, 0 replies; 13+ messages in thread
From: Kewei Xu @ 2021-07-17 10:17 UTC (permalink / raw)
  To: wsa
  Cc: matthias.bgg, robh+dt, linux-i2c, devicetree, linux-arm-kernel,
	linux-kernel, linux-mediatek, srv_heupstream, leilk.liu,
	qii.wang, yuhan.wei, kewei.xu, ot_daolong.zhu, liguo.zhang

Add a DT binding documentation for the MT8195 soc.

Signed-off-by: Kewei Xu <kewei.xu@mediatek.com>
---
 Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt b/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
index 7f0194fdd0cc..7c4915bc4439 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
@@ -15,6 +15,7 @@ Required properties:
       "mediatek,mt8173-i2c": for MediaTek MT8173
       "mediatek,mt8183-i2c": for MediaTek MT8183
       "mediatek,mt8192-i2c": for MediaTek MT8192
+      "mediatek,mt8195-i2c", "mediatek,mt8192-i2c": for MediaTek MT8195
       "mediatek,mt8516-i2c", "mediatek,mt2712-i2c": for MediaTek MT8516
   - reg: physical base address of the controller and dma base, length of memory
     mapped region.
-- 
2.18.0


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [PATCH v4 3/8] i2c: mediatek: Reset the handshake signal between i2c and dma
  2021-07-17 10:17 [PATCH V4 0/8] Introduce an attribute to choose timing setting Kewei Xu
  2021-07-17 10:17 ` [PATCH v4 1/8] i2c: mediatek: fixing the incorrect register offset Kewei Xu
  2021-07-17 10:17 ` [PATCH v4 2/8] dt-bindings: i2c: update bindings for MT8195 SoC Kewei Xu
@ 2021-07-17 10:17 ` Kewei Xu
  2021-08-11  8:41   ` Chen-Yu Tsai
  2021-07-17 10:17 ` [PATCH v4 4/8] i2c: mediatek: Dump i2c/dma register when a timeout occurs Kewei Xu
                   ` (4 subsequent siblings)
  7 siblings, 1 reply; 13+ messages in thread
From: Kewei Xu @ 2021-07-17 10:17 UTC (permalink / raw)
  To: wsa
  Cc: matthias.bgg, robh+dt, linux-i2c, devicetree, linux-arm-kernel,
	linux-kernel, linux-mediatek, srv_heupstream, leilk.liu,
	qii.wang, yuhan.wei, kewei.xu, ot_daolong.zhu, liguo.zhang

Due to changes in the hardware design of the handshaking signal
between i2c and dma, it is necessary to reset the handshaking
signal before each transfer to ensure that the multi-msgs can
be transferred correctly.

Signed-off-by: Kewei Xu <kewei.xu@mediatek.com>
---
 drivers/i2c/busses/i2c-mt65xx.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 222ff765e55d..c0108387f34b 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -47,6 +47,9 @@
 #define I2C_RD_TRANAC_VALUE		0x0001
 #define I2C_SCL_MIS_COMP_VALUE		0x0000
 #define I2C_CHN_CLR_FLAG		0x0000
+#define I2C_CLR_DEBUGCTR		0x0000
+#define I2C_RELIABILITY			0x0010
+#define I2C_DMAACK_ENABLE		0x0008
 
 #define I2C_DMA_CON_TX			0x0000
 #define I2C_DMA_CON_RX			0x0001
@@ -850,6 +853,17 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
 
 	reinit_completion(&i2c->msg_complete);
 
+	if (i2c->dev_comp->apdma_sync) {
+		mtk_i2c_writew(i2c, I2C_CLR_DEBUGCTR, OFFSET_DEBUGCTRL);
+		writel(I2C_DMA_HANDSHAKE_RST | I2C_DMA_WARM_RST,
+		       i2c->pdmabase + OFFSET_RST);
+		writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);
+		mtk_i2c_writew(i2c, I2C_HANDSHAKE_RST, OFFSET_SOFTRESET);
+		mtk_i2c_writew(i2c, I2C_CHN_CLR_FLAG, OFFSET_SOFTRESET);
+		mtk_i2c_writew(i2c, I2C_RELIABILITY | I2C_DMAACK_ENABLE,
+			       OFFSET_DEBUGCTRL);
+	}
+
 	control_reg = mtk_i2c_readw(i2c, OFFSET_CONTROL) &
 			~(I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS);
 	if ((i2c->speed_hz > I2C_MAX_FAST_MODE_PLUS_FREQ) || (left_num >= 1))
-- 
2.18.0


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [PATCH v4 4/8] i2c: mediatek: Dump i2c/dma register when a timeout occurs
  2021-07-17 10:17 [PATCH V4 0/8] Introduce an attribute to choose timing setting Kewei Xu
                   ` (2 preceding siblings ...)
  2021-07-17 10:17 ` [PATCH v4 3/8] i2c: mediatek: Reset the handshake signal between i2c and dma Kewei Xu
@ 2021-07-17 10:17 ` Kewei Xu
  2021-07-17 10:17 ` [PATCH v4 5/8] dt-bindings: i2c: add attribute default-timing-adjust Kewei Xu
                   ` (3 subsequent siblings)
  7 siblings, 0 replies; 13+ messages in thread
From: Kewei Xu @ 2021-07-17 10:17 UTC (permalink / raw)
  To: wsa
  Cc: matthias.bgg, robh+dt, linux-i2c, devicetree, linux-arm-kernel,
	linux-kernel, linux-mediatek, srv_heupstream, leilk.liu,
	qii.wang, yuhan.wei, kewei.xu, ot_daolong.zhu, liguo.zhang

When a timeout error occurs in i2c transter, it is usually related
to the i2c/dma IP hardware configuration. Therefore, the purpose of
this patch is to dump the key register values of i2c/dma when a
timeout occurs in i2c for debugging.

Signed-off-by: Kewei Xu <kewei.xu@mediatek.com>
---
 drivers/i2c/busses/i2c-mt65xx.c | 56 ++++++++++++++++++++++++++++++++-
 1 file changed, 55 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index c0108387f34b..abdbf27b6eb4 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -128,6 +128,7 @@ enum I2C_REGS_OFFSET {
 	OFFSET_HS,
 	OFFSET_SOFTRESET,
 	OFFSET_DCM_EN,
+	OFFSET_MULTI_DMA,
 	OFFSET_PATH_DIR,
 	OFFSET_DEBUGSTAT,
 	OFFSET_DEBUGCTRL,
@@ -195,6 +196,7 @@ static const u16 mt_i2c_regs_v2[] = {
 	[OFFSET_TRANSFER_LEN_AUX] = 0x44,
 	[OFFSET_CLOCK_DIV] = 0x48,
 	[OFFSET_SOFTRESET] = 0x50,
+	[OFFSET_MULTI_DMA] = 0x8c,
 	[OFFSET_SCL_MIS_COMP_POINT] = 0x90,
 	[OFFSET_DEBUGSTAT] = 0xe4,
 	[OFFSET_DEBUGCTRL] = 0xe8,
@@ -831,6 +833,57 @@ static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk)
 	return 0;
 }
 
+static void i2c_dump_register(struct mtk_i2c *i2c)
+{
+	dev_err(i2c->dev, "SLAVE_ADDR: 0x%x, INTR_MASK: 0x%x\n",
+		mtk_i2c_readw(i2c, OFFSET_SLAVE_ADDR),
+		mtk_i2c_readw(i2c, OFFSET_INTR_MASK));
+	dev_err(i2c->dev, "INTR_STAT: 0x%x, CONTROL: 0x%x\n",
+		mtk_i2c_readw(i2c, OFFSET_INTR_STAT),
+		mtk_i2c_readw(i2c, OFFSET_CONTROL));
+	dev_err(i2c->dev, "TRANSFER_LEN: 0x%x, TRANSAC_LEN: 0x%x\n",
+		mtk_i2c_readw(i2c, OFFSET_TRANSFER_LEN),
+		mtk_i2c_readw(i2c, OFFSET_TRANSAC_LEN));
+	dev_err(i2c->dev, "DELAY_LEN: 0x%x, HTIMING: 0x%x\n",
+		mtk_i2c_readw(i2c, OFFSET_DELAY_LEN),
+		mtk_i2c_readw(i2c, OFFSET_TIMING));
+	dev_err(i2c->dev, "START: 0x%x, EXT_CONF: 0x%x\n",
+		mtk_i2c_readw(i2c, OFFSET_START),
+		mtk_i2c_readw(i2c, OFFSET_EXT_CONF));
+	dev_err(i2c->dev, "HS: 0x%x, IO_CONFIG: 0x%x\n",
+		mtk_i2c_readw(i2c, OFFSET_HS),
+		mtk_i2c_readw(i2c, OFFSET_IO_CONFIG));
+	dev_err(i2c->dev, "DCM_EN: 0x%x, TRANSFER_LEN_AUX: 0x%x\n",
+		mtk_i2c_readw(i2c, OFFSET_DCM_EN),
+		mtk_i2c_readw(i2c, OFFSET_TRANSFER_LEN_AUX));
+	dev_err(i2c->dev, "CLOCK_DIV: 0x%x, FIFO_STAT: 0x%x\n",
+		mtk_i2c_readw(i2c, OFFSET_CLOCK_DIV),
+		mtk_i2c_readw(i2c, OFFSET_FIFO_STAT));
+	dev_err(i2c->dev, "DEBUGCTRL : 0x%x, DEBUGSTAT: 0x%x\n",
+		mtk_i2c_readw(i2c, OFFSET_DEBUGCTRL),
+		mtk_i2c_readw(i2c, OFFSET_DEBUGSTAT));
+	if (i2c->dev_comp->regs == mt_i2c_regs_v2) {
+		dev_err(i2c->dev, "LTIMING: 0x%x, MULTI_DMA: 0x%x\n",
+			mtk_i2c_readw(i2c, OFFSET_LTIMING),
+			mtk_i2c_readw(i2c, OFFSET_MULTI_DMA));
+	}
+	dev_err(i2c->dev, "\nDMA_INT_FLAG: 0x%x, DMA_INT_EN: 0x%x\n",
+		readl(i2c->pdmabase + OFFSET_INT_FLAG),
+		readl(i2c->pdmabase + OFFSET_INT_EN));
+	dev_err(i2c->dev, "DMA_EN: 0x%x, DMA_CON: 0x%x\n",
+		readl(i2c->pdmabase + OFFSET_EN),
+		readl(i2c->pdmabase + OFFSET_CON));
+	dev_err(i2c->dev, "DMA_TX_MEM_ADDR: 0x%x, DMA_RX_MEM_ADDR: 0x%x\n",
+		readl(i2c->pdmabase + OFFSET_TX_MEM_ADDR),
+		readl(i2c->pdmabase + OFFSET_RX_MEM_ADDR));
+	dev_err(i2c->dev, "DMA_TX_LEN: 0x%x, DMA_RX_LEN: 0x%x\n",
+		readl(i2c->pdmabase + OFFSET_TX_LEN),
+		readl(i2c->pdmabase + OFFSET_RX_LEN));
+	dev_err(i2c->dev, "DMA_TX_4G_MODE: 0x%x, DMA_RX_4G_MODE: 0x%x",
+		readl(i2c->pdmabase + OFFSET_TX_4G_MODE),
+		readl(i2c->pdmabase + OFFSET_RX_4G_MODE));
+}
+
 static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
 			       int num, int left_num)
 {
@@ -1048,7 +1101,8 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
 	}
 
 	if (ret == 0) {
-		dev_dbg(i2c->dev, "addr: %x, transfer timeout\n", msgs->addr);
+		dev_err(i2c->dev, "addr: %x, transfer timeout\n", msgs->addr);
+		i2c_dump_register(i2c);
 		mtk_i2c_init_hw(i2c);
 		return -ETIMEDOUT;
 	}
-- 
2.18.0


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [PATCH v4 5/8] dt-bindings: i2c: add attribute default-timing-adjust
  2021-07-17 10:17 [PATCH V4 0/8] Introduce an attribute to choose timing setting Kewei Xu
                   ` (3 preceding siblings ...)
  2021-07-17 10:17 ` [PATCH v4 4/8] i2c: mediatek: Dump i2c/dma register when a timeout occurs Kewei Xu
@ 2021-07-17 10:17 ` Kewei Xu
  2021-07-22  3:10   ` Rob Herring
  2021-07-17 10:17 ` [PATCH v4 6/8] i2c: mediatek: Add OFFSET_EXT_CONF setting back Kewei Xu
                   ` (2 subsequent siblings)
  7 siblings, 1 reply; 13+ messages in thread
From: Kewei Xu @ 2021-07-17 10:17 UTC (permalink / raw)
  To: wsa
  Cc: matthias.bgg, robh+dt, linux-i2c, devicetree, linux-arm-kernel,
	linux-kernel, linux-mediatek, srv_heupstream, leilk.liu,
	qii.wang, yuhan.wei, kewei.xu, ot_daolong.zhu, liguo.zhang

Add attribute default-timing-adjust for DT-binding document.

Fixes: be5ce0e97cc7 ("i2c: mediatek: Add i2c ac-timing adjust support")
Signed-off-by: Kewei Xu <kewei.xu@mediatek.com>
---
 Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt b/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
index 7c4915bc4439..7b80a11d4d4c 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
@@ -33,6 +33,8 @@ Optional properties:
   - mediatek,have-pmic: platform can control i2c form special pmic side.
     Only mt6589 and mt8135 support this feature.
   - mediatek,use-push-pull: IO config use push-pull mode.
+  - mediatek,default-timing-adjust: use default timing calculation, no timing
+    adjustment.
 
 Example:
 
-- 
2.18.0


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [PATCH v4 6/8] i2c: mediatek: Add OFFSET_EXT_CONF setting back
  2021-07-17 10:17 [PATCH V4 0/8] Introduce an attribute to choose timing setting Kewei Xu
                   ` (4 preceding siblings ...)
  2021-07-17 10:17 ` [PATCH v4 5/8] dt-bindings: i2c: add attribute default-timing-adjust Kewei Xu
@ 2021-07-17 10:17 ` Kewei Xu
  2021-07-17 10:17 ` [PATCH v4 7/8] i2c: mediatek: Isolate speed setting via dts for special devices Kewei Xu
  2021-07-17 10:17 ` [PATCH v4 8/8] i2c: mediatek: modify bus speed calculation formula Kewei Xu
  7 siblings, 0 replies; 13+ messages in thread
From: Kewei Xu @ 2021-07-17 10:17 UTC (permalink / raw)
  To: wsa
  Cc: matthias.bgg, robh+dt, linux-i2c, devicetree, linux-arm-kernel,
	linux-kernel, linux-mediatek, srv_heupstream, leilk.liu,
	qii.wang, yuhan.wei, kewei.xu, ot_daolong.zhu, liguo.zhang

In the commit be5ce0e97cc7 ("i2c: mediatek: Add i2c ac-timing adjust
support"), we miss setting OFFSET_EXT_CONF register if
i2c->dev_comp->timing_adjust is false, now add it back.

Fixes: be5ce0e97cc7 ("i2c: mediatek: Add i2c ac-timing adjust support")
Signed-off-by: Kewei Xu <kewei.xu@mediatek.com>
---
 drivers/i2c/busses/i2c-mt65xx.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index abdbf27b6eb4..a2a5a4ec1d81 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -41,6 +41,8 @@
 #define I2C_HANDSHAKE_RST		0x0020
 #define I2C_FIFO_ADDR_CLR		0x0001
 #define I2C_DELAY_LEN			0x0002
+#define I2C_ST_START_CON		0x8001
+#define I2C_FS_START_CON		0x1800
 #define I2C_TIME_CLR_VALUE		0x0000
 #define I2C_TIME_DEFAULT_VALUE		0x0003
 #define I2C_WRRD_TRANAC_VALUE		0x0002
@@ -484,6 +486,7 @@ static void mtk_i2c_clock_disable(struct mtk_i2c *i2c)
 static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
 {
 	u16 control_reg;
+	u16 ext_conf_val;
 
 	if (i2c->dev_comp->apdma_sync) {
 		writel(I2C_DMA_WARM_RST, i2c->pdmabase + OFFSET_RST);
@@ -518,8 +521,13 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
 	if (i2c->dev_comp->ltiming_adjust)
 		mtk_i2c_writew(i2c, i2c->ltiming_reg, OFFSET_LTIMING);
 
+	if (i2c->speed_hz <= I2C_MAX_STANDARD_MODE_FREQ)
+		ext_conf_val = I2C_ST_START_CON;
+	else
+		ext_conf_val = I2C_FS_START_CON;
+
 	if (i2c->dev_comp->timing_adjust) {
-		mtk_i2c_writew(i2c, i2c->ac_timing.ext, OFFSET_EXT_CONF);
+		ext_conf_val = i2c->ac_timing.ext;
 		mtk_i2c_writew(i2c, i2c->ac_timing.inter_clk_div,
 			       OFFSET_CLOCK_DIV);
 		mtk_i2c_writew(i2c, I2C_SCL_MIS_COMP_VALUE,
@@ -544,6 +552,7 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
 				       OFFSET_HS_STA_STO_AC_TIMING);
 		}
 	}
+	mtk_i2c_writew(i2c, ext_conf_val, OFFSET_EXT_CONF);
 
 	/* If use i2c pin from PMIC mt6397 side, need set PATH_DIR first */
 	if (i2c->have_pmic)
-- 
2.18.0


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [PATCH v4 7/8] i2c: mediatek: Isolate speed setting via dts for special devices
  2021-07-17 10:17 [PATCH V4 0/8] Introduce an attribute to choose timing setting Kewei Xu
                   ` (5 preceding siblings ...)
  2021-07-17 10:17 ` [PATCH v4 6/8] i2c: mediatek: Add OFFSET_EXT_CONF setting back Kewei Xu
@ 2021-07-17 10:17 ` Kewei Xu
  2021-07-17 10:17 ` [PATCH v4 8/8] i2c: mediatek: modify bus speed calculation formula Kewei Xu
  7 siblings, 0 replies; 13+ messages in thread
From: Kewei Xu @ 2021-07-17 10:17 UTC (permalink / raw)
  To: wsa
  Cc: matthias.bgg, robh+dt, linux-i2c, devicetree, linux-arm-kernel,
	linux-kernel, linux-mediatek, srv_heupstream, leilk.liu,
	qii.wang, yuhan.wei, kewei.xu, ot_daolong.zhu, liguo.zhang

In the commit be5ce0e97cc7 ("i2c: mediatek: Add i2c ac-timing adjust
support"), the I2C timing calculation has been revised to support
ac-timing adjustment, however that will break on some I2C components.
As a result we want to introduce a new setting "default-adjust-timing"
so those components can choose to use the old (default) timing algorithm.

Fixes: be5ce0e97cc7 ("i2c: mediatek: Add i2c ac-timing adjust support")
Signed-off-by: Kewei Xu <kewei.xu@mediatek.com>
---
 drivers/i2c/busses/i2c-mt65xx.c | 77 +++++++++++++++++++++++++++++++--
 1 file changed, 73 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index a2a5a4ec1d81..061775489380 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -65,6 +65,7 @@
 #define I2C_DMA_HARD_RST		0x0002
 #define I2C_DMA_HANDSHAKE_RST		0x0004
 
+#define I2C_DEFAULT_CLK_DIV		5
 #define MAX_SAMPLE_CNT_DIV		8
 #define MAX_STEP_CNT_DIV		64
 #define MAX_CLOCK_DIV			256
@@ -249,6 +250,7 @@ struct mtk_i2c {
 	struct clk *clk_arb;		/* Arbitrator clock for i2c */
 	bool have_pmic;			/* can use i2c pins from PMIC */
 	bool use_push_pull;		/* IO config push-pull mode */
+	bool default_timing_adjust;	/* no timing adjust mode */
 
 	u16 irq_stat;			/* interrupt status */
 	unsigned int clk_src_div;
@@ -526,7 +528,11 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
 	else
 		ext_conf_val = I2C_FS_START_CON;
 
-	if (i2c->dev_comp->timing_adjust) {
+	if (i2c->default_timing_adjust) {
+		if (i2c->dev_comp->timing_adjust)
+			mtk_i2c_writew(i2c, I2C_DEFAULT_CLK_DIV - 1,
+				       OFFSET_CLOCK_DIV);
+	} else if (i2c->dev_comp->timing_adjust) {
 		ext_conf_val = i2c->ac_timing.ext;
 		mtk_i2c_writew(i2c, i2c->ac_timing.inter_clk_div,
 			       OFFSET_CLOCK_DIV);
@@ -609,7 +615,7 @@ static int mtk_i2c_check_ac_timing(struct mtk_i2c *i2c,
 	unsigned int sample_ns = div_u64(1000000000ULL * (sample_cnt + 1),
 					 clk_src);
 
-	if (!i2c->dev_comp->timing_adjust)
+	if (i2c->default_timing_adjust || !i2c->dev_comp->timing_adjust)
 		return 0;
 
 	if (i2c->dev_comp->ltiming_adjust)
@@ -769,7 +775,65 @@ static int mtk_i2c_calculate_speed(struct mtk_i2c *i2c, unsigned int clk_src,
 	return 0;
 }
 
-static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk)
+static int mtk_i2c_set_speed_default_timing(struct mtk_i2c *i2c,
+					    unsigned int parent_clk)
+{
+	unsigned int clk_src;
+	unsigned int step_cnt;
+	unsigned int sample_cnt;
+	unsigned int l_step_cnt;
+	unsigned int l_sample_cnt;
+	unsigned int target_speed;
+	int ret;
+
+	if (i2c->dev_comp->timing_adjust)
+		i2c->clk_src_div *= I2C_DEFAULT_CLK_DIV;
+
+	clk_src = parent_clk / i2c->clk_src_div;
+	target_speed = i2c->speed_hz;
+
+	if (target_speed > I2C_MAX_FAST_MODE_PLUS_FREQ) {
+		/* Set master code speed register */
+		ret = mtk_i2c_calculate_speed(i2c, clk_src,
+					      I2C_MAX_FAST_MODE_FREQ,
+					      &l_step_cnt, &l_sample_cnt);
+		if (ret < 0)
+			return ret;
+
+		i2c->timing_reg = (l_sample_cnt << 8) | l_step_cnt;
+
+		/* Set the high speed mode register */
+		ret = mtk_i2c_calculate_speed(i2c, clk_src, target_speed,
+					      &step_cnt, &sample_cnt);
+		if (ret < 0)
+			return ret;
+
+		i2c->high_speed_reg = I2C_TIME_DEFAULT_VALUE |
+			(sample_cnt << 12) | (step_cnt << 8);
+
+		if (i2c->dev_comp->ltiming_adjust)
+			i2c->ltiming_reg = (l_sample_cnt << 6) | l_step_cnt |
+					   (sample_cnt << 12) | (step_cnt << 9);
+	} else {
+		ret = mtk_i2c_calculate_speed(i2c, clk_src, target_speed,
+					      &step_cnt, &sample_cnt);
+		if (ret < 0)
+			return ret;
+
+		i2c->timing_reg = (sample_cnt << 8) | step_cnt;
+
+		/* Disable the high speed transaction */
+		i2c->high_speed_reg = I2C_TIME_CLR_VALUE;
+
+		if (i2c->dev_comp->ltiming_adjust)
+			i2c->ltiming_reg = (sample_cnt << 6) | step_cnt;
+	}
+
+	return 0;
+}
+
+static int mtk_i2c_set_speed_adjust_timing(struct mtk_i2c *i2c,
+					   unsigned int parent_clk)
 {
 	unsigned int clk_src;
 	unsigned int step_cnt;
@@ -1254,6 +1318,8 @@ static int mtk_i2c_parse_dt(struct device_node *np, struct mtk_i2c *i2c)
 	i2c->have_pmic = of_property_read_bool(np, "mediatek,have-pmic");
 	i2c->use_push_pull =
 		of_property_read_bool(np, "mediatek,use-push-pull");
+	i2c->default_timing_adjust =
+		of_property_read_bool(np, "mediatek,default-timing-adjust");
 
 	i2c_parse_fw_timings(i2c->dev, &i2c->timing_info, true);
 
@@ -1333,7 +1399,10 @@ static int mtk_i2c_probe(struct platform_device *pdev)
 
 	strlcpy(i2c->adap.name, I2C_DRV_NAME, sizeof(i2c->adap.name));
 
-	ret = mtk_i2c_set_speed(i2c, clk_get_rate(clk));
+	if (i2c->default_timing_adjust)
+		ret = mtk_i2c_set_speed_default_timing(i2c, clk_get_rate(clk));
+	else
+		ret = mtk_i2c_set_speed_adjust_timing(i2c, clk_get_rate(clk));
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to set the speed.\n");
 		return -EINVAL;
-- 
2.18.0


^ permalink raw reply	[flat|nested] 13+ messages in thread

* [PATCH v4 8/8] i2c: mediatek: modify bus speed calculation formula
  2021-07-17 10:17 [PATCH V4 0/8] Introduce an attribute to choose timing setting Kewei Xu
                   ` (6 preceding siblings ...)
  2021-07-17 10:17 ` [PATCH v4 7/8] i2c: mediatek: Isolate speed setting via dts for special devices Kewei Xu
@ 2021-07-17 10:17 ` Kewei Xu
  7 siblings, 0 replies; 13+ messages in thread
From: Kewei Xu @ 2021-07-17 10:17 UTC (permalink / raw)
  To: wsa
  Cc: matthias.bgg, robh+dt, linux-i2c, devicetree, linux-arm-kernel,
	linux-kernel, linux-mediatek, srv_heupstream, leilk.liu,
	qii.wang, yuhan.wei, kewei.xu, ot_daolong.zhu, liguo.zhang

When clock-div is 0 or greater than 1, the bus speed
calculated by the old speed calculation formula will be
larger than the target speed. So we update the formula.

Signed-off-by: Kewei Xu <kewei.xu@mediatek.com>
---
 drivers/i2c/busses/i2c-mt65xx.c | 35 +++++++++++++++++++++++----------
 1 file changed, 25 insertions(+), 10 deletions(-)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 061775489380..45939f919085 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -68,11 +68,12 @@
 #define I2C_DEFAULT_CLK_DIV		5
 #define MAX_SAMPLE_CNT_DIV		8
 #define MAX_STEP_CNT_DIV		64
-#define MAX_CLOCK_DIV			256
+#define MAX_CLOCK_DIV_8BITS		256
+#define MAX_CLOCK_DIV_5BITS		32
 #define MAX_HS_STEP_CNT_DIV		8
-#define I2C_STANDARD_MODE_BUFFER	(1000 / 2)
-#define I2C_FAST_MODE_BUFFER		(300 / 2)
-#define I2C_FAST_MODE_PLUS_BUFFER	(20 / 2)
+#define I2C_STANDARD_MODE_BUFFER	(1000 / 3)
+#define I2C_FAST_MODE_BUFFER		(300 / 3)
+#define I2C_FAST_MODE_PLUS_BUFFER	(20 / 3)
 
 #define I2C_CONTROL_RS                  (0x1 << 1)
 #define I2C_CONTROL_DMA_EN              (0x1 << 2)
@@ -719,14 +720,26 @@ static int mtk_i2c_calculate_speed(struct mtk_i2c *i2c, unsigned int clk_src,
 	unsigned int best_mul;
 	unsigned int cnt_mul;
 	int ret = -EINVAL;
+	int clock_div_constraint = 0;
 
 	if (target_speed > I2C_MAX_HIGH_SPEED_MODE_FREQ)
 		target_speed = I2C_MAX_HIGH_SPEED_MODE_FREQ;
 
+	if (i2c->default_timing_adjust) {
+		clock_div_constraint = 0;
+	} else if (i2c->dev_comp->ltiming_adjust &&
+		   i2c->ac_timing.inter_clk_div > 1) {
+		clock_div_constraint = 1;
+	} else if (i2c->dev_comp->ltiming_adjust &&
+		   i2c->ac_timing.inter_clk_div == 0) {
+		clock_div_constraint = -1;
+	}
+
 	max_step_cnt = mtk_i2c_max_step_cnt(target_speed);
 	base_step_cnt = max_step_cnt;
 	/* Find the best combination */
-	opt_div = DIV_ROUND_UP(clk_src >> 1, target_speed);
+	opt_div = DIV_ROUND_UP(clk_src >> 1, target_speed) +
+		  clock_div_constraint;
 	best_mul = MAX_SAMPLE_CNT_DIV * max_step_cnt;
 
 	/* Search for the best pair (sample_cnt, step_cnt) with
@@ -761,7 +774,8 @@ static int mtk_i2c_calculate_speed(struct mtk_i2c *i2c, unsigned int clk_src,
 	sample_cnt = base_sample_cnt;
 	step_cnt = base_step_cnt;
 
-	if ((clk_src / (2 * sample_cnt * step_cnt)) > target_speed) {
+	if ((clk_src / (2 * (sample_cnt * step_cnt - clock_div_constraint))) >
+		 target_speed) {
 		/* In this case, hardware can't support such
 		 * low i2c_bus_freq
 		 */
@@ -848,13 +862,16 @@ static int mtk_i2c_set_speed_adjust_timing(struct mtk_i2c *i2c,
 	target_speed = i2c->speed_hz;
 	parent_clk /= i2c->clk_src_div;
 
-	if (i2c->dev_comp->timing_adjust)
-		max_clk_div = MAX_CLOCK_DIV;
+	if (i2c->dev_comp->timing_adjust && i2c->dev_comp->ltiming_adjust)
+		max_clk_div = MAX_CLOCK_DIV_5BITS;
+	else if (i2c->dev_comp->timing_adjust)
+		max_clk_div = MAX_CLOCK_DIV_8BITS;
 	else
 		max_clk_div = 1;
 
 	for (clk_div = 1; clk_div <= max_clk_div; clk_div++) {
 		clk_src = parent_clk / clk_div;
+		i2c->ac_timing.inter_clk_div = clk_div - 1;
 
 		if (target_speed > I2C_MAX_FAST_MODE_PLUS_FREQ) {
 			/* Set master code speed register */
@@ -901,8 +918,6 @@ static int mtk_i2c_set_speed_adjust_timing(struct mtk_i2c *i2c,
 		break;
 	}
 
-	i2c->ac_timing.inter_clk_div = clk_div - 1;
-
 	return 0;
 }
 
-- 
2.18.0


^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH v4 5/8] dt-bindings: i2c: add attribute default-timing-adjust
  2021-07-17 10:17 ` [PATCH v4 5/8] dt-bindings: i2c: add attribute default-timing-adjust Kewei Xu
@ 2021-07-22  3:10   ` Rob Herring
  2021-08-18  6:37     ` Kewei Xu
  0 siblings, 1 reply; 13+ messages in thread
From: Rob Herring @ 2021-07-22  3:10 UTC (permalink / raw)
  To: Kewei Xu
  Cc: wsa, matthias.bgg, linux-i2c, devicetree, linux-arm-kernel,
	linux-kernel, linux-mediatek, srv_heupstream, leilk.liu,
	qii.wang, yuhan.wei, ot_daolong.zhu, liguo.zhang

On Sat, Jul 17, 2021 at 06:17:56PM +0800, Kewei Xu wrote:
> Add attribute default-timing-adjust for DT-binding document.
> 
> Fixes: be5ce0e97cc7 ("i2c: mediatek: Add i2c ac-timing adjust support")
> Signed-off-by: Kewei Xu <kewei.xu@mediatek.com>
> ---
>  Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt b/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
> index 7c4915bc4439..7b80a11d4d4c 100644
> --- a/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
> +++ b/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
> @@ -33,6 +33,8 @@ Optional properties:
>    - mediatek,have-pmic: platform can control i2c form special pmic side.
>      Only mt6589 and mt8135 support this feature.
>    - mediatek,use-push-pull: IO config use push-pull mode.
> +  - mediatek,default-timing-adjust: use default timing calculation, no timing
> +    adjustment.

'mediatek,use-default-timing' perhaps as it means don't adjust anything.

>  
>  Example:
>  
> -- 
> 2.18.0
> 
> 

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH v4 3/8] i2c: mediatek: Reset the handshake signal between i2c and dma
  2021-07-17 10:17 ` [PATCH v4 3/8] i2c: mediatek: Reset the handshake signal between i2c and dma Kewei Xu
@ 2021-08-11  8:41   ` Chen-Yu Tsai
  2021-08-21  7:40     ` Kewei Xu
  0 siblings, 1 reply; 13+ messages in thread
From: Chen-Yu Tsai @ 2021-08-11  8:41 UTC (permalink / raw)
  To: Kewei Xu
  Cc: wsa, Matthias Brugger, Rob Herring, linux-i2c, Devicetree List,
	moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE, LKML,
	moderated list:ARM/Mediatek SoC support, srv_heupstream,
	leilk.liu, qii.wang, yuhan.wei, ot_daolong.zhu, liguo.zhang

Hi,

On Sat, Jul 17, 2021 at 6:29 PM Kewei Xu <kewei.xu@mediatek.com> wrote:
>
> Due to changes in the hardware design of the handshaking signal
> between i2c and dma, it is necessary to reset the handshaking
> signal before each transfer to ensure that the multi-msgs can
> be transferred correctly.

This also affects MT8192. Has this been tested on that SoC as well?

> Signed-off-by: Kewei Xu <kewei.xu@mediatek.com>
> ---
>  drivers/i2c/busses/i2c-mt65xx.c | 14 ++++++++++++++
>  1 file changed, 14 insertions(+)
>
> diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
> index 222ff765e55d..c0108387f34b 100644
> --- a/drivers/i2c/busses/i2c-mt65xx.c
> +++ b/drivers/i2c/busses/i2c-mt65xx.c
> @@ -47,6 +47,9 @@
>  #define I2C_RD_TRANAC_VALUE            0x0001
>  #define I2C_SCL_MIS_COMP_VALUE         0x0000
>  #define I2C_CHN_CLR_FLAG               0x0000
> +#define I2C_CLR_DEBUGCTR               0x0000
> +#define I2C_RELIABILITY                        0x0010
> +#define I2C_DMAACK_ENABLE              0x0008
>
>  #define I2C_DMA_CON_TX                 0x0000
>  #define I2C_DMA_CON_RX                 0x0001
> @@ -850,6 +853,17 @@ static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs,
>
>         reinit_completion(&i2c->msg_complete);
>
> +       if (i2c->dev_comp->apdma_sync) {
> +               mtk_i2c_writew(i2c, I2C_CLR_DEBUGCTR, OFFSET_DEBUGCTRL);
> +               writel(I2C_DMA_HANDSHAKE_RST | I2C_DMA_WARM_RST,
> +                      i2c->pdmabase + OFFSET_RST);
> +               writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);

I2C_DMA_WARM_RST is self-clearing. Is I2C_DMA_HANDSHAKE_RST not
self-clearing? If both are self-clearing, don't you need to wait and
check for them to cleared? If they aren't self-clearing, do you need
to delay some time for them to complete?

> +               mtk_i2c_writew(i2c, I2C_HANDSHAKE_RST, OFFSET_SOFTRESET);
> +               mtk_i2c_writew(i2c, I2C_CHN_CLR_FLAG, OFFSET_SOFTRESET);

Same here. No time delay needed?

> +               mtk_i2c_writew(i2c, I2C_RELIABILITY | I2C_DMAACK_ENABLE,
> +                              OFFSET_DEBUGCTRL);

A comment explaining what the section above does would be nice. AFAICU
this is force resetting the DMA handling.


Regards
ChenYu

> +       }
> +
>         control_reg = mtk_i2c_readw(i2c, OFFSET_CONTROL) &
>                         ~(I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS);
>         if ((i2c->speed_hz > I2C_MAX_FAST_MODE_PLUS_FREQ) || (left_num >= 1))
> --
> 2.18.0
> _______________________________________________
> Linux-mediatek mailing list
> Linux-mediatek@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-mediatek

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH v4 5/8] dt-bindings: i2c: add attribute default-timing-adjust
  2021-07-22  3:10   ` Rob Herring
@ 2021-08-18  6:37     ` Kewei Xu
  0 siblings, 0 replies; 13+ messages in thread
From: Kewei Xu @ 2021-08-18  6:37 UTC (permalink / raw)
  To: Rob Herring
  Cc: wsa, matthias.bgg, linux-i2c, devicetree, linux-arm-kernel,
	linux-kernel, linux-mediatek, srv_heupstream, leilk.liu,
	qii.wang, yuhan.wei, ot_daolong.zhu, liguo.zhang

On Wed, 2021-07-21 at 21:10 -0600, Rob Herring wrote:
> On Sat, Jul 17, 2021 at 06:17:56PM +0800, Kewei Xu wrote:
> > Add attribute default-timing-adjust for DT-binding document.
> > 
> > Fixes: be5ce0e97cc7 ("i2c: mediatek: Add i2c ac-timing adjust
> > support")
> > Signed-off-by: Kewei Xu <kewei.xu@mediatek.com>
> > ---
> >  Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
> > b/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
> > index 7c4915bc4439..7b80a11d4d4c 100644
> > --- a/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
> > +++ b/Documentation/devicetree/bindings/i2c/i2c-mt65xx.txt
> > @@ -33,6 +33,8 @@ Optional properties:
> >    - mediatek,have-pmic: platform can control i2c form special pmic
> > side.
> >      Only mt6589 and mt8135 support this feature.
> >    - mediatek,use-push-pull: IO config use push-pull mode.
> > +  - mediatek,default-timing-adjust: use default timing
> > calculation, no timing
> > +    adjustment.
> 
> 'mediatek,use-default-timing' perhaps as it means don't adjust
> anything.
> 
> >  
> >  Example:
> >  
> > -- 
> > 2.18.0
> > 
Hi Rob,

Thanks for your suggestion. We will use "mediatek,use-default-timing"
instead of "mediatek,default-timing-adjust" in the next version of
patch.

Thanks
kewei

^ permalink raw reply	[flat|nested] 13+ messages in thread

* Re: [PATCH v4 3/8] i2c: mediatek: Reset the handshake signal between i2c and dma
  2021-08-11  8:41   ` Chen-Yu Tsai
@ 2021-08-21  7:40     ` Kewei Xu
  0 siblings, 0 replies; 13+ messages in thread
From: Kewei Xu @ 2021-08-21  7:40 UTC (permalink / raw)
  To: Chen-Yu Tsai
  Cc: wsa, Matthias Brugger, Rob Herring, linux-i2c, Devicetree List,
	moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE, LKML,
	moderated list:ARM/Mediatek SoC support, srv_heupstream,
	leilk.liu, qii.wang, yuhan.wei, ot_daolong.zhu, liguo.zhang

On Wed, 2021-08-11 at 16:41 +0800, Chen-Yu Tsai wrote:
> Hi,
> 
> On Sat, Jul 17, 2021 at 6:29 PM Kewei Xu <kewei.xu@mediatek.com>
> wrote:
> > 
> > Due to changes in the hardware design of the handshaking signal
> > between i2c and dma, it is necessary to reset the handshaking
> > signal before each transfer to ensure that the multi-msgs can
> > be transferred correctly.
> 
> This also affects MT8192. Has this been tested on that SoC as well?

Yes, It has been tested on MT8192.

> 
> > Signed-off-by: Kewei Xu <kewei.xu@mediatek.com>
> > ---
> >  drivers/i2c/busses/i2c-mt65xx.c | 14 ++++++++++++++
> >  1 file changed, 14 insertions(+)
> > 
> > diff --git a/drivers/i2c/busses/i2c-mt65xx.c
> > b/drivers/i2c/busses/i2c-mt65xx.c
> > index 222ff765e55d..c0108387f34b 100644
> > --- a/drivers/i2c/busses/i2c-mt65xx.c
> > +++ b/drivers/i2c/busses/i2c-mt65xx.c
> > @@ -47,6 +47,9 @@
> >  #define I2C_RD_TRANAC_VALUE            0x0001
> >  #define I2C_SCL_MIS_COMP_VALUE         0x0000
> >  #define I2C_CHN_CLR_FLAG               0x0000
> > +#define I2C_CLR_DEBUGCTR               0x0000
> > +#define I2C_RELIABILITY                        0x0010
> > +#define I2C_DMAACK_ENABLE              0x0008
> > 
> >  #define I2C_DMA_CON_TX                 0x0000
> >  #define I2C_DMA_CON_RX                 0x0001
> > @@ -850,6 +853,17 @@ static int mtk_i2c_do_transfer(struct mtk_i2c
> > *i2c, struct i2c_msg *msgs,
> > 
> >         reinit_completion(&i2c->msg_complete);
> > 
> > +       if (i2c->dev_comp->apdma_sync) {
> > +               mtk_i2c_writew(i2c, I2C_CLR_DEBUGCTR,
> > OFFSET_DEBUGCTRL);
> > +               writel(I2C_DMA_HANDSHAKE_RST | I2C_DMA_WARM_RST,
> > +                      i2c->pdmabase + OFFSET_RST);
> > +               writel(I2C_DMA_CLR_FLAG, i2c->pdmabase +
> > OFFSET_RST);
> 
> I2C_DMA_WARM_RST is self-clearing. Is I2C_DMA_HANDSHAKE_RST not
> self-clearing? If both are self-clearing, don't you need to wait and
> check for them to cleared? If they aren't self-clearing, do you need
> to delay some time for them to complete?
> 

Thank you for your suggestion. We will appropriately add the delay in
the next version of patch according to the hardware behavior
characteristics. 

Regards
Kewei

> > +               mtk_i2c_writew(i2c, I2C_HANDSHAKE_RST,
> > OFFSET_SOFTRESET);
> > +               mtk_i2c_writew(i2c, I2C_CHN_CLR_FLAG,
> > OFFSET_SOFTRESET);
> 
> Same here. No time delay needed?
> 
> > +               mtk_i2c_writew(i2c, I2C_RELIABILITY |
> > I2C_DMAACK_ENABLE,
> > +                              OFFSET_DEBUGCTRL);
> 
> A comment explaining what the section above does would be nice.
> AFAICU
> this is force resetting the DMA handling.
> 
> 
> Regards
> ChenYu
> 
> > +       }
> > +
> >         control_reg = mtk_i2c_readw(i2c, OFFSET_CONTROL) &
> >                         ~(I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS);
> >         if ((i2c->speed_hz > I2C_MAX_FAST_MODE_PLUS_FREQ) ||
> > (left_num >= 1))
> > --
> > 2.18.0
> > _______________________________________________
> > Linux-mediatek mailing list
> > Linux-mediatek@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-mediatek

^ permalink raw reply	[flat|nested] 13+ messages in thread

end of thread, other threads:[~2021-08-21  7:40 UTC | newest]

Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-17 10:17 [PATCH V4 0/8] Introduce an attribute to choose timing setting Kewei Xu
2021-07-17 10:17 ` [PATCH v4 1/8] i2c: mediatek: fixing the incorrect register offset Kewei Xu
2021-07-17 10:17 ` [PATCH v4 2/8] dt-bindings: i2c: update bindings for MT8195 SoC Kewei Xu
2021-07-17 10:17 ` [PATCH v4 3/8] i2c: mediatek: Reset the handshake signal between i2c and dma Kewei Xu
2021-08-11  8:41   ` Chen-Yu Tsai
2021-08-21  7:40     ` Kewei Xu
2021-07-17 10:17 ` [PATCH v4 4/8] i2c: mediatek: Dump i2c/dma register when a timeout occurs Kewei Xu
2021-07-17 10:17 ` [PATCH v4 5/8] dt-bindings: i2c: add attribute default-timing-adjust Kewei Xu
2021-07-22  3:10   ` Rob Herring
2021-08-18  6:37     ` Kewei Xu
2021-07-17 10:17 ` [PATCH v4 6/8] i2c: mediatek: Add OFFSET_EXT_CONF setting back Kewei Xu
2021-07-17 10:17 ` [PATCH v4 7/8] i2c: mediatek: Isolate speed setting via dts for special devices Kewei Xu
2021-07-17 10:17 ` [PATCH v4 8/8] i2c: mediatek: modify bus speed calculation formula Kewei Xu

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