| Message ID | 20230415104104.5537-3-aford173@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/6] drm: bridge: samsung-dsim: Support multi-lane calculations | expand |
On 4/15/23 12:41, Adam Ford wrote: > Fetch the clock rate of "sclk_mipi" (or "pll_clk") instead of > having an entry in the device tree for samsung,pll-clock-frequency. > > Signed-off-by: Adam Ford <aford173@gmail.com> > --- > drivers/gpu/drm/bridge/samsung-dsim.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c > index 9fec32b44e05..73f0c3fbbdf5 100644 > --- a/drivers/gpu/drm/bridge/samsung-dsim.c > +++ b/drivers/gpu/drm/bridge/samsung-dsim.c > @@ -1744,11 +1744,6 @@ static int samsung_dsim_parse_dt(struct samsung_dsim *dsi) > struct device_node *node = dev->of_node; > int ret; > > - ret = samsung_dsim_of_read_u32(node, "samsung,pll-clock-frequency", > - &dsi->pll_clk_rate); > - if (ret < 0) > - return ret; > - > ret = samsung_dsim_of_read_u32(node, "samsung,burst-clock-frequency", > &dsi->burst_clk_rate); > if (ret < 0) Does this break compatibility with old samsung DTs ?
On Sun, Apr 16, 2023 at 5:08 PM Marek Vasut <marex@denx.de> wrote: > > On 4/15/23 12:41, Adam Ford wrote: > > Fetch the clock rate of "sclk_mipi" (or "pll_clk") instead of > > having an entry in the device tree for samsung,pll-clock-frequency. > > > > Signed-off-by: Adam Ford <aford173@gmail.com> > > --- > > drivers/gpu/drm/bridge/samsung-dsim.c | 12 ++++++------ > > 1 file changed, 6 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c > > index 9fec32b44e05..73f0c3fbbdf5 100644 > > --- a/drivers/gpu/drm/bridge/samsung-dsim.c > > +++ b/drivers/gpu/drm/bridge/samsung-dsim.c > > @@ -1744,11 +1744,6 @@ static int samsung_dsim_parse_dt(struct samsung_dsim *dsi) > > struct device_node *node = dev->of_node; > > int ret; > > > > - ret = samsung_dsim_of_read_u32(node, "samsung,pll-clock-frequency", > > - &dsi->pll_clk_rate); > > - if (ret < 0) > > - return ret; > > - > > ret = samsung_dsim_of_read_u32(node, "samsung,burst-clock-frequency", > > &dsi->burst_clk_rate); > > if (ret < 0) > > Does this break compatibility with old samsung DTs ? My goal here was to declutter the device tree stuff and fetch data automatically if possible. What if I changed this to make them optional? If they exist, we can use them, if they don't exist, we could read the clock rate. Would that be acceptable? adam
On 4/18/23 04:29, Adam Ford wrote: > On Sun, Apr 16, 2023 at 5:08 PM Marek Vasut <marex@denx.de> wrote: >> >> On 4/15/23 12:41, Adam Ford wrote: >>> Fetch the clock rate of "sclk_mipi" (or "pll_clk") instead of >>> having an entry in the device tree for samsung,pll-clock-frequency. >>> >>> Signed-off-by: Adam Ford <aford173@gmail.com> >>> --- >>> drivers/gpu/drm/bridge/samsung-dsim.c | 12 ++++++------ >>> 1 file changed, 6 insertions(+), 6 deletions(-) >>> >>> diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c >>> index 9fec32b44e05..73f0c3fbbdf5 100644 >>> --- a/drivers/gpu/drm/bridge/samsung-dsim.c >>> +++ b/drivers/gpu/drm/bridge/samsung-dsim.c >>> @@ -1744,11 +1744,6 @@ static int samsung_dsim_parse_dt(struct samsung_dsim *dsi) >>> struct device_node *node = dev->of_node; >>> int ret; >>> >>> - ret = samsung_dsim_of_read_u32(node, "samsung,pll-clock-frequency", >>> - &dsi->pll_clk_rate); >>> - if (ret < 0) >>> - return ret; >>> - >>> ret = samsung_dsim_of_read_u32(node, "samsung,burst-clock-frequency", >>> &dsi->burst_clk_rate); >>> if (ret < 0) >> >> Does this break compatibility with old samsung DTs ? > > My goal here was to declutter the device tree stuff and fetch data > automatically if possible. What if I changed this to make them > optional? If they exist, we can use them, if they don't exist, we > could read the clock rate. Would that be acceptable? If you do not see any potential problem with ignoring the DT property altogether, that would be better of course, but I think you cannot do that with old DTs, so you should retain backward compatibility fallback, yes. What do you think ?
Am Dienstag, dem 18.04.2023 um 10:30 +0200 schrieb Marek Vasut: > On 4/18/23 04:29, Adam Ford wrote: > > On Sun, Apr 16, 2023 at 5:08 PM Marek Vasut <marex@denx.de> wrote: > > > > > > On 4/15/23 12:41, Adam Ford wrote: > > > > Fetch the clock rate of "sclk_mipi" (or "pll_clk") instead of > > > > having an entry in the device tree for samsung,pll-clock-frequency. > > > > > > > > Signed-off-by: Adam Ford <aford173@gmail.com> > > > > --- > > > > drivers/gpu/drm/bridge/samsung-dsim.c | 12 ++++++------ > > > > 1 file changed, 6 insertions(+), 6 deletions(-) > > > > > > > > diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c > > > > index 9fec32b44e05..73f0c3fbbdf5 100644 > > > > --- a/drivers/gpu/drm/bridge/samsung-dsim.c > > > > +++ b/drivers/gpu/drm/bridge/samsung-dsim.c > > > > @@ -1744,11 +1744,6 @@ static int samsung_dsim_parse_dt(struct samsung_dsim *dsi) > > > > struct device_node *node = dev->of_node; > > > > int ret; > > > > > > > > - ret = samsung_dsim_of_read_u32(node, "samsung,pll-clock-frequency", > > > > - &dsi->pll_clk_rate); > > > > - if (ret < 0) > > > > - return ret; > > > > - > > > > ret = samsung_dsim_of_read_u32(node, "samsung,burst-clock-frequency", > > > > &dsi->burst_clk_rate); > > > > if (ret < 0) > > > > > > Does this break compatibility with old samsung DTs ? > > > > My goal here was to declutter the device tree stuff and fetch data > > automatically if possible. What if I changed this to make them > > optional? If they exist, we can use them, if they don't exist, we > > could read the clock rate. Would that be acceptable? > > If you do not see any potential problem with ignoring the DT property > altogether, that would be better of course, but I think you cannot do > that with old DTs, so you should retain backward compatibility fallback, > yes. What do you think ? I'm very much in favor of this patch, but I also think we shouldn't risk breaking Samsung devices, where we don't now 100% that the input clock rate provided by the clock driver is correct. So I think the right approach is to use "samsung,pll-clock-frequency" when present in DT and get it from the clock provider otherwise. Then just remove the property from the DTs where we can validate that the input clock rate is correct, i.e. all i.MX8M*. Regards, Lucas
On Tue, Apr 18, 2023 at 3:47 AM Lucas Stach <l.stach@pengutronix.de> wrote: > > Am Dienstag, dem 18.04.2023 um 10:30 +0200 schrieb Marek Vasut: > > On 4/18/23 04:29, Adam Ford wrote: > > > On Sun, Apr 16, 2023 at 5:08 PM Marek Vasut <marex@denx.de> wrote: > > > > > > > > On 4/15/23 12:41, Adam Ford wrote: > > > > > Fetch the clock rate of "sclk_mipi" (or "pll_clk") instead of > > > > > having an entry in the device tree for samsung,pll-clock-frequency. > > > > > > > > > > Signed-off-by: Adam Ford <aford173@gmail.com> > > > > > --- > > > > > drivers/gpu/drm/bridge/samsung-dsim.c | 12 ++++++------ > > > > > 1 file changed, 6 insertions(+), 6 deletions(-) > > > > > > > > > > diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c > > > > > index 9fec32b44e05..73f0c3fbbdf5 100644 > > > > > --- a/drivers/gpu/drm/bridge/samsung-dsim.c > > > > > +++ b/drivers/gpu/drm/bridge/samsung-dsim.c > > > > > @@ -1744,11 +1744,6 @@ static int samsung_dsim_parse_dt(struct samsung_dsim *dsi) > > > > > struct device_node *node = dev->of_node; > > > > > int ret; > > > > > > > > > > - ret = samsung_dsim_of_read_u32(node, "samsung,pll-clock-frequency", > > > > > - &dsi->pll_clk_rate); > > > > > - if (ret < 0) > > > > > - return ret; > > > > > - > > > > > ret = samsung_dsim_of_read_u32(node, "samsung,burst-clock-frequency", > > > > > &dsi->burst_clk_rate); > > > > > if (ret < 0) > > > > > > > > Does this break compatibility with old samsung DTs ? > > > > > > My goal here was to declutter the device tree stuff and fetch data > > > automatically if possible. What if I changed this to make them > > > optional? If they exist, we can use them, if they don't exist, we > > > could read the clock rate. Would that be acceptable? > > > > If you do not see any potential problem with ignoring the DT property > > altogether, that would be better of course, but I think you cannot do > > that with old DTs, so you should retain backward compatibility fallback, > > yes. What do you think ? > > I'm very much in favor of this patch, but I also think we shouldn't > risk breaking Samsung devices, where we don't now 100% that the input > clock rate provided by the clock driver is correct. > > So I think the right approach is to use "samsung,pll-clock-frequency" > when present in DT and get it from the clock provider otherwise. Then > just remove the property from the DTs where we can validate that the > input clock rate is correct, i.e. all i.MX8M*. I'll update this accordingly when I do a V2 of this series. adam > > Regards, > Lucas
On 15.04.2023 12:41, Adam Ford wrote: > Fetch the clock rate of "sclk_mipi" (or "pll_clk") instead of > having an entry in the device tree for samsung,pll-clock-frequency. > > Signed-off-by: Adam Ford <aford173@gmail.com> This one breaks DSI panel operation on my Exynos-based Trats, Trats2 and TM2e boards. I've didn't check the details, but probably something is missing in the dts to make it working properly. Surprisingly the display is still working fine on Arndale board with DSI TC358764 bridge. > --- > drivers/gpu/drm/bridge/samsung-dsim.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c > index 9fec32b44e05..73f0c3fbbdf5 100644 > --- a/drivers/gpu/drm/bridge/samsung-dsim.c > +++ b/drivers/gpu/drm/bridge/samsung-dsim.c > @@ -1744,11 +1744,6 @@ static int samsung_dsim_parse_dt(struct samsung_dsim *dsi) > struct device_node *node = dev->of_node; > int ret; > > - ret = samsung_dsim_of_read_u32(node, "samsung,pll-clock-frequency", > - &dsi->pll_clk_rate); > - if (ret < 0) > - return ret; > - > ret = samsung_dsim_of_read_u32(node, "samsung,burst-clock-frequency", > &dsi->burst_clk_rate); > if (ret < 0) > @@ -1823,13 +1818,18 @@ int samsung_dsim_probe(struct platform_device *pdev) > if (IS_ERR(dsi->clks[i])) { > if (strcmp(clk_names[i], "sclk_mipi") == 0) { > dsi->clks[i] = devm_clk_get(dev, OLD_SCLK_MIPI_CLK_NAME); > - if (!IS_ERR(dsi->clks[i])) > + if (!IS_ERR(dsi->clks[i])) { > + dsi->pll_clk_rate = clk_get_rate(dsi->clks[i]); > continue; > + } > } > > dev_info(dev, "failed to get the clock: %s\n", clk_names[i]); > return PTR_ERR(dsi->clks[i]); > } > + > + if (strcmp(clk_names[i], "sclk_mipi") == 0) > + dsi->pll_clk_rate = clk_get_rate(dsi->clks[i]); > } > > dsi->reg_base = devm_platform_ioremap_resource(pdev, 0); Best regards
On Fri, Apr 21, 2023 at 6:25 AM Marek Szyprowski <m.szyprowski@samsung.com> wrote: > > On 15.04.2023 12:41, Adam Ford wrote: > > Fetch the clock rate of "sclk_mipi" (or "pll_clk") instead of > > having an entry in the device tree for samsung,pll-clock-frequency. > > > > Signed-off-by: Adam Ford <aford173@gmail.com> > > This one breaks DSI panel operation on my Exynos-based Trats, Trats2 and > TM2e boards. I've didn't check the details, but probably something is > missing in the dts to make it working properly. Surprisingly the display > is still working fine on Arndale board with DSI TC358764 bridge. Thanks for testing! I'm going to update this patch in V2 which will use the device tree settings if they are present. If they are missing, they will fetch the clock rate instead of failing. This way, it should mitigate breaking your boards, but it will allow the imx8m mini/nano/plus to eliminate hard-coding some device tree entries since they can be fetched automatically. adam > > > --- > > drivers/gpu/drm/bridge/samsung-dsim.c | 12 ++++++------ > > 1 file changed, 6 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c > > index 9fec32b44e05..73f0c3fbbdf5 100644 > > --- a/drivers/gpu/drm/bridge/samsung-dsim.c > > +++ b/drivers/gpu/drm/bridge/samsung-dsim.c > > @@ -1744,11 +1744,6 @@ static int samsung_dsim_parse_dt(struct samsung_dsim *dsi) > > struct device_node *node = dev->of_node; > > int ret; > > > > - ret = samsung_dsim_of_read_u32(node, "samsung,pll-clock-frequency", > > - &dsi->pll_clk_rate); > > - if (ret < 0) > > - return ret; > > - > > ret = samsung_dsim_of_read_u32(node, "samsung,burst-clock-frequency", > > &dsi->burst_clk_rate); > > if (ret < 0) > > @@ -1823,13 +1818,18 @@ int samsung_dsim_probe(struct platform_device *pdev) > > if (IS_ERR(dsi->clks[i])) { > > if (strcmp(clk_names[i], "sclk_mipi") == 0) { > > dsi->clks[i] = devm_clk_get(dev, OLD_SCLK_MIPI_CLK_NAME); > > - if (!IS_ERR(dsi->clks[i])) > > + if (!IS_ERR(dsi->clks[i])) { > > + dsi->pll_clk_rate = clk_get_rate(dsi->clks[i]); > > continue; > > + } > > } > > > > dev_info(dev, "failed to get the clock: %s\n", clk_names[i]); > > return PTR_ERR(dsi->clks[i]); > > } > > + > > + if (strcmp(clk_names[i], "sclk_mipi") == 0) > > + dsi->pll_clk_rate = clk_get_rate(dsi->clks[i]); > > } > > > > dsi->reg_base = devm_platform_ioremap_resource(pdev, 0); > > Best regards > -- > Marek Szyprowski, PhD > Samsung R&D Institute Poland >
diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge/samsung-dsim.c index 9fec32b44e05..73f0c3fbbdf5 100644 --- a/drivers/gpu/drm/bridge/samsung-dsim.c +++ b/drivers/gpu/drm/bridge/samsung-dsim.c @@ -1744,11 +1744,6 @@ static int samsung_dsim_parse_dt(struct samsung_dsim *dsi) struct device_node *node = dev->of_node; int ret; - ret = samsung_dsim_of_read_u32(node, "samsung,pll-clock-frequency", - &dsi->pll_clk_rate); - if (ret < 0) - return ret; - ret = samsung_dsim_of_read_u32(node, "samsung,burst-clock-frequency", &dsi->burst_clk_rate); if (ret < 0) @@ -1823,13 +1818,18 @@ int samsung_dsim_probe(struct platform_device *pdev) if (IS_ERR(dsi->clks[i])) { if (strcmp(clk_names[i], "sclk_mipi") == 0) { dsi->clks[i] = devm_clk_get(dev, OLD_SCLK_MIPI_CLK_NAME); - if (!IS_ERR(dsi->clks[i])) + if (!IS_ERR(dsi->clks[i])) { + dsi->pll_clk_rate = clk_get_rate(dsi->clks[i]); continue; + } } dev_info(dev, "failed to get the clock: %s\n", clk_names[i]); return PTR_ERR(dsi->clks[i]); } + + if (strcmp(clk_names[i], "sclk_mipi") == 0) + dsi->pll_clk_rate = clk_get_rate(dsi->clks[i]); } dsi->reg_base = devm_platform_ioremap_resource(pdev, 0);
Fetch the clock rate of "sclk_mipi" (or "pll_clk") instead of having an entry in the device tree for samsung,pll-clock-frequency. Signed-off-by: Adam Ford <aford173@gmail.com> --- drivers/gpu/drm/bridge/samsung-dsim.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-)