| Message ID | 1612348525-13364-1-git-send-email-qii.wang@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | i2c: mediatek: Get device clock-stretch time via dts | expand |
Hi, On Wed, 2021-02-03 at 18:35 +0800, qii.wang@mediatek.com wrote: > 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> > --- Can it merge into 5.12? or do I need to resend the patch? Thanks, Qii
Hi Qii, On Wed, Feb 3, 2021 at 6:43 PM <qii.wang@mediatek.com> wrote: > > 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); > + I think this new property "clock-stretch-ns" is for the same purpose of "i2c-scl-falling-time-ns" + "i2c-scl-rising-time-ns" defined in Documentation/devicetree/bindings/i2c/i2c.txt? > 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
Hi, On Tue, 2021-03-02 at 19:30 +0800, Ikjoon Jang wrote: > Hi Qii, > > > > @@ -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); > > + > > I think this new property "clock-stretch-ns" is for the same purpose of > "i2c-scl-falling-time-ns" + "i2c-scl-rising-time-ns" defined in > Documentation/devicetree/bindings/i2c/i2c.txt? > I haven't find the corresponding instructions;and this patch is for the problem caused by clock-stretch when the scl is pulled. > > 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
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");