This allows us to raise DRAM bandiwth to a high enough value for a stable picture on i.mx8mq. We pick a bandwidth that should be sufficient for 4k@60Hz.
Modelled like mdp5_kms. Signed-off-by: Guido Günther <[email protected]> --- drivers/gpu/drm/imx/dcss/dcss-dev.c | 47 +++++++++++++++++++++++++++-- drivers/gpu/drm/imx/dcss/dcss-dev.h | 3 ++ 2 files changed, 48 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/imx/dcss/dcss-dev.c b/drivers/gpu/drm/imx/dcss/dcss-dev.c index c849533ca83e..e336f03448d6 100644 --- a/drivers/gpu/drm/imx/dcss/dcss-dev.c +++ b/drivers/gpu/drm/imx/dcss/dcss-dev.c @@ -15,6 +15,9 @@ #include "dcss-dev.h" #include "dcss-kms.h" +/* sufficient for 4K at 60 Hz */ +#define DCSS_BW_MAX GBps_to_icc(2) + static void dcss_clocks_enable(struct dcss_dev *dcss) { clk_prepare_enable(dcss->axi_clk); @@ -162,6 +165,31 @@ static void dcss_clks_release(struct dcss_dev *dcss) devm_clk_put(dcss->dev, dcss->apb_clk); } +static int dcss_init_icc(struct dcss_dev *dcss) +{ + int ret; + struct icc_path *icc_path; + + /* Optional interconnect request */ + icc_path = of_icc_get(dcss->dev, NULL); + if (IS_ERR(icc_path)) { + ret = PTR_ERR(icc_path); + if (ret == -EPROBE_DEFER) + return ret; + /* no interconnect support is not necessarily a fatal + * condition, the platform may simply not have an + * interconnect driver yet. But warn about it in case + * bootloader didn't setup bus clocks high enough for + * scanout. + */ + dev_warn(dcss->dev, "No interconnect support may cause display underflows!\n"); + return 0; + } + dcss->icc_path = icc_path; + dcss->icc_peak_bw = DCSS_BW_MAX; + return 0; +} + struct dcss_dev *dcss_dev_create(struct device *dev, bool hdmi_output) { struct platform_device *pdev = to_platform_device(dev); @@ -190,10 +218,14 @@ struct dcss_dev *dcss_dev_create(struct device *dev, bool hdmi_output) dcss->devtype = devtype; dcss->hdmi_output = hdmi_output; + ret = dcss_init_icc(dcss); + if (ret < 0) + goto err; + ret = dcss_clks_init(dcss); if (ret) { dev_err(dev, "clocks initialization failed\n"); - goto err; + goto icc_err; } dcss->of_port = of_graph_get_port_by_id(dev->of_node, 0); @@ -223,7 +255,8 @@ struct dcss_dev *dcss_dev_create(struct device *dev, bool hdmi_output) clks_err: dcss_clks_release(dcss); - +icc_err: + icc_put(dcss->icc_path); err: kfree(dcss); @@ -243,6 +276,8 @@ void dcss_dev_destroy(struct dcss_dev *dcss) dcss_clks_release(dcss); + icc_put(dcss->icc_path); + kfree(dcss); } @@ -267,6 +302,8 @@ int dcss_dev_suspend(struct device *dev) dcss_clocks_disable(dcss); + icc_set_bw(dcss->icc_path, 0, 0); + return 0; } @@ -281,6 +318,8 @@ int dcss_dev_resume(struct device *dev) return 0; } + icc_set_bw(dcss->icc_path, 0, dcss->icc_peak_bw); + dcss_clocks_enable(dcss); dcss_blkctl_cfg(dcss->blkctl); @@ -307,6 +346,8 @@ int dcss_dev_runtime_suspend(struct device *dev) dcss_clocks_disable(dcss); + icc_set_bw(dcss->icc_path, 0, 0); + return 0; } @@ -314,6 +355,8 @@ int dcss_dev_runtime_resume(struct device *dev) { struct dcss_dev *dcss = dcss_drv_dev_to_dcss(dev); + icc_set_bw(dcss->icc_path, 0, dcss->icc_peak_bw); + dcss_clocks_enable(dcss); dcss_blkctl_cfg(dcss->blkctl); diff --git a/drivers/gpu/drm/imx/dcss/dcss-dev.h b/drivers/gpu/drm/imx/dcss/dcss-dev.h index c642ae17837f..1b35a6f0d0d4 100644 --- a/drivers/gpu/drm/imx/dcss/dcss-dev.h +++ b/drivers/gpu/drm/imx/dcss/dcss-dev.h @@ -8,6 +8,7 @@ #include <drm/drm_fourcc.h> #include <linux/io.h> +#include <linux/interconnect.h> #include <video/videomode.h> #define SET 0x04 @@ -85,6 +86,8 @@ struct dcss_dev { struct clk *pll_phy_ref_clk; bool hdmi_output; + struct icc_path *icc_path; + u32 icc_peak_bw; void (*disable_callback)(void *data); struct completion disable_completion; -- 2.29.2
