From: Qii Wang <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 3/3] i2c: mediatek: Use scl_int_delay_ns to compensate clock-stretching
Date: Sat, 17 Apr 2021 14:46:52 +0800 [thread overview]
Message-ID: <1618642012-10444-4-git-send-email-qii.wang@mediatek.com> (raw)
In-Reply-To: <1618642012-10444-1-git-send-email-qii.wang@mediatek.com>
The parameters of tSU,STA/tHD,STA/tSU,STOP maybe out of spec due
to device clock-stretch or circuit loss, we could get a suitable
scl_int_delay_ns from i2c_timings to compensate 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 bf25acb..5ddfa4e 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -231,6 +231,7 @@ struct mtk_i2c {
struct i2c_adapter adap; /* i2c host adapter */
struct device *dev;
struct completion msg_complete;
+ struct i2c_timings timing_info;
/* set in i2c probe */
void __iomem *base; /* i2c base addr */
@@ -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->timing_info.scl_int_delay_ns, clk_ns);
if (su_sta_cnt > max_sta_cnt)
return -1;
@@ -1176,6 +1178,8 @@ static int mtk_i2c_parse_dt(struct device_node *np, struct mtk_i2c *i2c)
i2c->use_push_pull =
of_property_read_bool(np, "mediatek,use-push-pull");
+ i2c_parse_fw_timings(i2c->dev, &i2c->timing_info, true);
+
return 0;
}
--
1.9.1
next prev parent reply other threads:[~2021-04-17 6:47 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-17 6:46 [PATCH 0/3] Add some fix patches Qii Wang
2021-04-17 6:46 ` [PATCH 1/3] i2c: mediatek: Fix send master code at more than 1MHz Qii Wang
2021-04-17 20:06 ` Wolfram Sang
2021-04-17 6:46 ` [PATCH 2/3] i2c: mediatek: Fix wrong dma sync flag Qii Wang
2021-04-17 20:07 ` Wolfram Sang
2021-04-17 6:46 ` Qii Wang [this message]
2021-04-17 20:09 ` [PATCH 3/3] i2c: mediatek: Use scl_int_delay_ns to compensate clock-stretching Wolfram Sang
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