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From: <qii.wang@mediatek.com>
To: <wsa@the-dreams.de>
Cc: <matthias.bgg@gmail.com>, <linux-i2c@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-kernel@vger.kernel.org>,
	<linux-mediatek@lists.infradead.org>,
	<srv_heupstream@mediatek.com>, <leilk.liu@mediatek.com>,
	<qii.wang@mediatek.com>
Subject: [PATCH] i2c: mediatek: Get device clock-stretch time via dts
Date: Wed, 3 Feb 2021 18:35:25 +0800	[thread overview]
Message-ID: <1612348525-13364-1-git-send-email-qii.wang@mediatek.com> (raw)

From: Qii Wang <qii.wang@mediatek.com>

tSU,STA/tHD,STA/tSU,STOP maybe out of spec due to device
clock-stretching or circuit loss, we could get device
clock-stretch time from dts to adjust these parameters
to meet the spec via EXT_CONF register.

Signed-off-by: Qii Wang <qii.wang@mediatek.com>
---
 drivers/i2c/busses/i2c-mt65xx.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 2ffd2f3..47c7255 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -245,6 +245,7 @@ struct mtk_i2c {
 	u16 irq_stat;			/* interrupt status */
 	unsigned int clk_src_div;
 	unsigned int speed_hz;		/* The speed in transfer */
+	unsigned int clock_stretch_ns;
 	enum mtk_trans_op op;
 	u16 timing_reg;
 	u16 high_speed_reg;
@@ -607,7 +608,8 @@ static int mtk_i2c_check_ac_timing(struct mtk_i2c *i2c,
 	else
 		clk_ns = sample_ns / 2;
 
-	su_sta_cnt = DIV_ROUND_UP(spec->min_su_sta_ns, clk_ns);
+	su_sta_cnt = DIV_ROUND_UP(spec->min_su_sta_ns + i2c->clock_stretch_ns,
+				  clk_ns);
 	if (su_sta_cnt > max_sta_cnt)
 		return -1;
 
@@ -1171,6 +1173,8 @@ static int mtk_i2c_parse_dt(struct device_node *np, struct mtk_i2c *i2c)
 	if (i2c->clk_src_div == 0)
 		return -EINVAL;
 
+	of_property_read_u32(np, "clock-stretch-ns", &i2c->clock_stretch_ns);
+
 	i2c->have_pmic = of_property_read_bool(np, "mediatek,have-pmic");
 	i2c->use_push_pull =
 		of_property_read_bool(np, "mediatek,use-push-pull");
-- 
1.9.1


WARNING: multiple messages have this Message-ID (diff)
From: <qii.wang@mediatek.com>
To: <wsa@the-dreams.de>
Cc: qii.wang@mediatek.com, srv_heupstream@mediatek.com,
	leilk.liu@mediatek.com, linux-kernel@vger.kernel.org,
	linux-mediatek@lists.infradead.org, linux-i2c@vger.kernel.org,
	matthias.bgg@gmail.com, linux-arm-kernel@lists.infradead.org
Subject: [PATCH] i2c: mediatek: Get device clock-stretch time via dts
Date: Wed, 3 Feb 2021 18:35:25 +0800	[thread overview]
Message-ID: <1612348525-13364-1-git-send-email-qii.wang@mediatek.com> (raw)

From: Qii Wang <qii.wang@mediatek.com>

tSU,STA/tHD,STA/tSU,STOP maybe out of spec due to device
clock-stretching or circuit loss, we could get device
clock-stretch time from dts to adjust these parameters
to meet the spec via EXT_CONF register.

Signed-off-by: Qii Wang <qii.wang@mediatek.com>
---
 drivers/i2c/busses/i2c-mt65xx.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 2ffd2f3..47c7255 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -245,6 +245,7 @@ struct mtk_i2c {
 	u16 irq_stat;			/* interrupt status */
 	unsigned int clk_src_div;
 	unsigned int speed_hz;		/* The speed in transfer */
+	unsigned int clock_stretch_ns;
 	enum mtk_trans_op op;
 	u16 timing_reg;
 	u16 high_speed_reg;
@@ -607,7 +608,8 @@ static int mtk_i2c_check_ac_timing(struct mtk_i2c *i2c,
 	else
 		clk_ns = sample_ns / 2;
 
-	su_sta_cnt = DIV_ROUND_UP(spec->min_su_sta_ns, clk_ns);
+	su_sta_cnt = DIV_ROUND_UP(spec->min_su_sta_ns + i2c->clock_stretch_ns,
+				  clk_ns);
 	if (su_sta_cnt > max_sta_cnt)
 		return -1;
 
@@ -1171,6 +1173,8 @@ static int mtk_i2c_parse_dt(struct device_node *np, struct mtk_i2c *i2c)
 	if (i2c->clk_src_div == 0)
 		return -EINVAL;
 
+	of_property_read_u32(np, "clock-stretch-ns", &i2c->clock_stretch_ns);
+
 	i2c->have_pmic = of_property_read_bool(np, "mediatek,have-pmic");
 	i2c->use_push_pull =
 		of_property_read_bool(np, "mediatek,use-push-pull");
-- 
1.9.1
_______________________________________________
Linux-mediatek mailing list
Linux-mediatek@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-mediatek

WARNING: multiple messages have this Message-ID (diff)
From: <qii.wang@mediatek.com>
To: <wsa@the-dreams.de>
Cc: qii.wang@mediatek.com, srv_heupstream@mediatek.com,
	leilk.liu@mediatek.com, linux-kernel@vger.kernel.org,
	linux-mediatek@lists.infradead.org, linux-i2c@vger.kernel.org,
	matthias.bgg@gmail.com, linux-arm-kernel@lists.infradead.org
Subject: [PATCH] i2c: mediatek: Get device clock-stretch time via dts
Date: Wed, 3 Feb 2021 18:35:25 +0800	[thread overview]
Message-ID: <1612348525-13364-1-git-send-email-qii.wang@mediatek.com> (raw)

From: Qii Wang <qii.wang@mediatek.com>

tSU,STA/tHD,STA/tSU,STOP maybe out of spec due to device
clock-stretching or circuit loss, we could get device
clock-stretch time from dts to adjust these parameters
to meet the spec via EXT_CONF register.

Signed-off-by: Qii Wang <qii.wang@mediatek.com>
---
 drivers/i2c/busses/i2c-mt65xx.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 2ffd2f3..47c7255 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -245,6 +245,7 @@ struct mtk_i2c {
 	u16 irq_stat;			/* interrupt status */
 	unsigned int clk_src_div;
 	unsigned int speed_hz;		/* The speed in transfer */
+	unsigned int clock_stretch_ns;
 	enum mtk_trans_op op;
 	u16 timing_reg;
 	u16 high_speed_reg;
@@ -607,7 +608,8 @@ static int mtk_i2c_check_ac_timing(struct mtk_i2c *i2c,
 	else
 		clk_ns = sample_ns / 2;
 
-	su_sta_cnt = DIV_ROUND_UP(spec->min_su_sta_ns, clk_ns);
+	su_sta_cnt = DIV_ROUND_UP(spec->min_su_sta_ns + i2c->clock_stretch_ns,
+				  clk_ns);
 	if (su_sta_cnt > max_sta_cnt)
 		return -1;
 
@@ -1171,6 +1173,8 @@ static int mtk_i2c_parse_dt(struct device_node *np, struct mtk_i2c *i2c)
 	if (i2c->clk_src_div == 0)
 		return -EINVAL;
 
+	of_property_read_u32(np, "clock-stretch-ns", &i2c->clock_stretch_ns);
+
 	i2c->have_pmic = of_property_read_bool(np, "mediatek,have-pmic");
 	i2c->use_push_pull =
 		of_property_read_bool(np, "mediatek,use-push-pull");
-- 
1.9.1
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

             reply	other threads:[~2021-02-03 10:36 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-03 10:35 qii.wang [this message]
2021-02-03 10:35 ` [PATCH] i2c: mediatek: Get device clock-stretch time via dts qii.wang
2021-02-03 10:35 ` qii.wang
2021-03-01 12:22 ` Qii Wang
2021-03-01 12:22   ` Qii Wang
2021-03-01 12:22   ` Qii Wang
2021-03-02 11:30 ` Ikjoon Jang
2021-03-02 11:30   ` Ikjoon Jang
2021-03-02 11:30   ` Ikjoon Jang
2021-03-02 12:32   ` Qii Wang
2021-03-02 12:32     ` Qii Wang
2021-03-02 12:32     ` Qii Wang

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