| Message ID | 20220311143532.265091-4-paul.kocialkowski@bootlin.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Allwinner A31/A83T MIPI CSI-2 and A31 ISP / CSI Rework | expand |
Hi Paul! Dne petek, 11. marec 2022 ob 15:34:49 CET je Paul Kocialkowski napisal(a): > Since the bus clock alone is not enough to get access to the registers, > don't pass it to regmap and manage it instead just like the other > clocks. > Let me ask it in another way, is bus clock needed only for register access? If yes, it makes sense to keep it enabled only during register access. Best regards, Jernej > Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com> > --- > drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c | 10 ++++++++-- > drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h | 1 + > 2 files changed, 9 insertions(+), 2 deletions(-) > > diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c b/drivers/ media/platform/sunxi/sun6i-csi/sun6i_csi.c > index 5fbaa1e99412..dc79f3c14336 100644 > --- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c > +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c > @@ -827,13 +827,19 @@ static int sun6i_csi_resource_request(struct sun6i_csi_device *csi_dev, > if (IS_ERR(io_base)) > return PTR_ERR(io_base); > > - csi_dev->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "bus", io_base, > - &sun6i_csi_regmap_config); > + csi_dev->regmap = devm_regmap_init_mmio(&pdev->dev, io_base, > + &sun6i_csi_regmap_config); > if (IS_ERR(csi_dev->regmap)) { > dev_err(&pdev->dev, "Failed to init register map\n"); > return PTR_ERR(csi_dev->regmap); > } > > + csi_dev->clk_bus = devm_clk_get(&pdev->dev, "bus"); > + if (IS_ERR(csi_dev->clk_bus)) { > + dev_err(&pdev->dev, "Unable to acquire bus clock\n"); > + return PTR_ERR(csi_dev->clk_bus); > + } > + > csi_dev->clk_mod = devm_clk_get(&pdev->dev, "mod"); > if (IS_ERR(csi_dev->clk_mod)) { > dev_err(&pdev->dev, "Unable to acquire csi clock\n"); > diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h b/drivers/ media/platform/sunxi/sun6i-csi/sun6i_csi.h > index e4e7ac6c869f..356661b413f8 100644 > --- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h > +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h > @@ -51,6 +51,7 @@ struct sun6i_csi_device { > struct sun6i_video video; > > struct regmap *regmap; > + struct clk *clk_bus; > struct clk *clk_mod; > struct clk *clk_ram; > struct reset_control *reset; > -- > 2.35.1 > >
Hi Jernej, On Tue 15 Mar 22, 20:22, Jernej Škrabec wrote: > Hi Paul! > > Dne petek, 11. marec 2022 ob 15:34:49 CET je Paul Kocialkowski napisal(a): > > Since the bus clock alone is not enough to get access to the registers, > > don't pass it to regmap and manage it instead just like the other > > clocks. > > > > Let me ask it in another way, is bus clock needed only for register access? If > yes, it makes sense to keep it enabled only during register access. Ah right, I lost sight that what regmap will do is to enable/disable the clock around register access. I understand there might be an advantage in terms of power consumption here. I haven't checked specifically, but since it was used like that before it's probably fine. Out of curiosity: is there any noticeable latency added by the process? Cheers, Paul > Best regards, > Jernej > > > Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com> > > --- > > drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c | 10 ++++++++-- > > drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h | 1 + > > 2 files changed, 9 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c b/drivers/ > media/platform/sunxi/sun6i-csi/sun6i_csi.c > > index 5fbaa1e99412..dc79f3c14336 100644 > > --- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c > > +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c > > @@ -827,13 +827,19 @@ static int sun6i_csi_resource_request(struct > sun6i_csi_device *csi_dev, > > if (IS_ERR(io_base)) > > return PTR_ERR(io_base); > > > > - csi_dev->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "bus", > io_base, > > - > &sun6i_csi_regmap_config); > > + csi_dev->regmap = devm_regmap_init_mmio(&pdev->dev, io_base, > > + > &sun6i_csi_regmap_config); > > if (IS_ERR(csi_dev->regmap)) { > > dev_err(&pdev->dev, "Failed to init register map\n"); > > return PTR_ERR(csi_dev->regmap); > > } > > > > + csi_dev->clk_bus = devm_clk_get(&pdev->dev, "bus"); > > + if (IS_ERR(csi_dev->clk_bus)) { > > + dev_err(&pdev->dev, "Unable to acquire bus clock\n"); > > + return PTR_ERR(csi_dev->clk_bus); > > + } > > + > > csi_dev->clk_mod = devm_clk_get(&pdev->dev, "mod"); > > if (IS_ERR(csi_dev->clk_mod)) { > > dev_err(&pdev->dev, "Unable to acquire csi clock\n"); > > diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h b/drivers/ > media/platform/sunxi/sun6i-csi/sun6i_csi.h > > index e4e7ac6c869f..356661b413f8 100644 > > --- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h > > +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h > > @@ -51,6 +51,7 @@ struct sun6i_csi_device { > > struct sun6i_video video; > > > > struct regmap *regmap; > > + struct clk *clk_bus; > > struct clk *clk_mod; > > struct clk *clk_ram; > > struct reset_control *reset; > > -- > > 2.35.1 > > > > > >
diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c index 5fbaa1e99412..dc79f3c14336 100644 --- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c @@ -827,13 +827,19 @@ static int sun6i_csi_resource_request(struct sun6i_csi_device *csi_dev, if (IS_ERR(io_base)) return PTR_ERR(io_base); - csi_dev->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "bus", io_base, - &sun6i_csi_regmap_config); + csi_dev->regmap = devm_regmap_init_mmio(&pdev->dev, io_base, + &sun6i_csi_regmap_config); if (IS_ERR(csi_dev->regmap)) { dev_err(&pdev->dev, "Failed to init register map\n"); return PTR_ERR(csi_dev->regmap); } + csi_dev->clk_bus = devm_clk_get(&pdev->dev, "bus"); + if (IS_ERR(csi_dev->clk_bus)) { + dev_err(&pdev->dev, "Unable to acquire bus clock\n"); + return PTR_ERR(csi_dev->clk_bus); + } + csi_dev->clk_mod = devm_clk_get(&pdev->dev, "mod"); if (IS_ERR(csi_dev->clk_mod)) { dev_err(&pdev->dev, "Unable to acquire csi clock\n"); diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h index e4e7ac6c869f..356661b413f8 100644 --- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h +++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h @@ -51,6 +51,7 @@ struct sun6i_csi_device { struct sun6i_video video; struct regmap *regmap; + struct clk *clk_bus; struct clk *clk_mod; struct clk *clk_ram; struct reset_control *reset;
Since the bus clock alone is not enough to get access to the registers, don't pass it to regmap and manage it instead just like the other clocks. Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com> --- drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.c | 10 ++++++++-- drivers/media/platform/sunxi/sun6i-csi/sun6i_csi.h | 1 + 2 files changed, 9 insertions(+), 2 deletions(-)