From 7d690f936e9bc9fbd6394fb3d4ad181af03ee393 Mon Sep 17 00:00:00 2001 From: AngeloGioacchino Del Regno Date: Thu, 23 Mar 2023 10:08:22 +0100 Subject: drm/panfrost: Add basic support for speed binning Some SoCs implementing ARM Mali GPUs are subject to speed binning: this means that some versions of the same SoC model may need to be limited to a slower frequency compared to the other: this is being addressed by reading nvmem (usually, an eFuse array) containing a number that identifies the speed binning of the chip, which is usually related to silicon quality. To address such situation, add basic support for reading the speed-bin through nvmem, as to make it possible to specify the supported hardware in the OPP table for GPUs. This commit also keeps compatibility with any platform that does not specify (and does not even support) speed-binning. Signed-off-by: AngeloGioacchino Del Regno Reviewed-by: Boris Brezillon Signed-off-by: Boris Brezillon Link: https://patchwork.freedesktop.org/patch/msgid/20230323090822.61766-3-angelogioacchino.delregno@collabora.com --- drivers/gpu/drm/panfrost/panfrost_devfreq.c | 30 +++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c index fe5f12f16a63..58dfb15a8757 100644 --- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c @@ -4,6 +4,7 @@ #include #include #include +#include #include #include @@ -82,6 +83,31 @@ static struct devfreq_dev_profile panfrost_devfreq_profile = { .get_dev_status = panfrost_devfreq_get_dev_status, }; +static int panfrost_read_speedbin(struct device *dev) +{ + u32 val; + int ret; + + ret = nvmem_cell_read_variable_le_u32(dev, "speed-bin", &val); + if (ret) { + /* + * -ENOENT means that this platform doesn't support speedbins + * as it didn't declare any speed-bin nvmem: in this case, we + * keep going without it; any other error means that we are + * supposed to read the bin value, but we failed doing so. + */ + if (ret != -ENOENT) { + DRM_DEV_ERROR(dev, "Cannot read speed-bin (%d).", ret); + return ret; + } + + return 0; + } + DRM_DEV_DEBUG(dev, "Using speed-bin = 0x%x\n", val); + + return devm_pm_opp_set_supported_hw(dev, &val, 1); +} + int panfrost_devfreq_init(struct panfrost_device *pfdev) { int ret; @@ -101,6 +127,10 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev) return 0; } + ret = panfrost_read_speedbin(dev); + if (ret) + return ret; + ret = devm_pm_opp_set_regulators(dev, pfdev->comp->supply_names); if (ret) { /* Continue if the optional regulator is missing */ -- cgit v1.2.3