Add OPP and SoC core voltage scaling support to the display controller driver. This is required for enabling system-wide DVFS on pre-Tegra186 SoCs.
Tested-by: Peter Geis pgwipeout@gmail.com # Ouya T30 Tested-by: Paul Fertser fercerpav@gmail.com # PAZ00 T20 Tested-by: Nicolas Chauvet kwizart@gmail.com # PAZ00 T20 and TK1 T124 Tested-by: Matt Merhar mattmerhar@protonmail.com # Ouya T30 Signed-off-by: Dmitry Osipenko digetx@gmail.com --- drivers/gpu/drm/tegra/dc.c | 79 ++++++++++++++++++++++++++++++++++++++ drivers/gpu/drm/tegra/dc.h | 2 + 2 files changed, 81 insertions(+)
diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c index a457ee954a49..eb70eee8992a 100644 --- a/drivers/gpu/drm/tegra/dc.c +++ b/drivers/gpu/drm/tegra/dc.c @@ -11,9 +11,12 @@ #include <linux/interconnect.h> #include <linux/module.h> #include <linux/of_device.h> +#include <linux/pm_domain.h> +#include <linux/pm_opp.h> #include <linux/pm_runtime.h> #include <linux/reset.h>
+#include <soc/tegra/common.h> #include <soc/tegra/pmc.h>
#include <drm/drm_atomic.h> @@ -1834,6 +1837,52 @@ int tegra_dc_state_setup_clock(struct tegra_dc *dc, return 0; }
+static void tegra_dc_update_voltage_state(struct tegra_dc *dc, + struct tegra_dc_state *state) +{ + unsigned long rate, pstate; + struct dev_pm_opp *opp; + int err; + + if (!dc->has_opp_table) + return; + + /* calculate actual pixel clock rate which depends on internal divider */ + rate = DIV_ROUND_UP(clk_get_rate(dc->clk) * 2, state->div + 2); + + /* find suitable OPP for the rate */ + opp = dev_pm_opp_find_freq_ceil(dc->dev, &rate); + + /* + * Very high resolution modes may results in a clock rate that is + * above the characterized maximum. In this case it's okay to fall + * back to the characterized maximum. + */ + if (opp == ERR_PTR(-ERANGE)) + opp = dev_pm_opp_find_freq_floor(dc->dev, &rate); + + if (IS_ERR(opp)) { + dev_err(dc->dev, "failed to find OPP for %luHz: %pe\n", + rate, opp); + return; + } + + pstate = dev_pm_opp_get_required_pstate(opp, 0); + dev_pm_opp_put(opp); + + /* + * The minimum core voltage depends on the pixel clock rate (which + * depends on internal clock divider of the CRTC) and not on the + * rate of the display controller clock. This is why we're not using + * dev_pm_opp_set_rate() API and instead controlling the power domain + * directly. + */ + err = dev_pm_genpd_set_performance_state(dc->dev, pstate); + if (err) + dev_err(dc->dev, "failed to set power domain state to %lu: %d\n", + pstate, err); +} + static void tegra_dc_set_clock_rate(struct tegra_dc *dc, struct tegra_dc_state *state) { @@ -1867,6 +1916,8 @@ static void tegra_dc_set_clock_rate(struct tegra_dc *dc, DRM_DEBUG_KMS("rate: %lu, div: %u\n", clk_get_rate(dc->clk), state->div); DRM_DEBUG_KMS("pclk: %lu\n", state->pclk); + + tegra_dc_update_voltage_state(dc, state); }
static void tegra_dc_stop(struct tegra_dc *dc) @@ -2057,6 +2108,13 @@ static void tegra_crtc_atomic_disable(struct drm_crtc *crtc, err = host1x_client_suspend(&dc->client); if (err < 0) dev_err(dc->dev, "failed to suspend: %d\n", err); + + if (dc->has_opp_table) { + err = dev_pm_genpd_set_performance_state(dc->dev, 0); + if (err) + dev_err(dc->dev, + "failed to clear power domain state: %d\n", err); + } }
static void tegra_crtc_atomic_enable(struct drm_crtc *crtc, @@ -3058,6 +3116,23 @@ static int tegra_dc_couple(struct tegra_dc *dc) return 0; }
+static int tegra_dc_init_opp_table(struct tegra_dc *dc) +{ + struct tegra_core_opp_params opp_params = {}; + int err; + + err = devm_tegra_core_dev_init_opp_table(dc->dev, &opp_params); + if (err && err != -ENODEV) + return err; + + if (err) + dc->has_opp_table = false; + else + dc->has_opp_table = true; + + return 0; +} + static int tegra_dc_probe(struct platform_device *pdev) { u64 dma_mask = dma_get_mask(pdev->dev.parent); @@ -3123,6 +3198,10 @@ static int tegra_dc_probe(struct platform_device *pdev) tegra_powergate_power_off(dc->powergate); }
+ err = tegra_dc_init_opp_table(dc); + if (err < 0) + return err; + dc->regs = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(dc->regs)) return PTR_ERR(dc->regs); diff --git a/drivers/gpu/drm/tegra/dc.h b/drivers/gpu/drm/tegra/dc.h index c9c4c45c0518..3f91a10ea6c7 100644 --- a/drivers/gpu/drm/tegra/dc.h +++ b/drivers/gpu/drm/tegra/dc.h @@ -101,6 +101,8 @@ struct tegra_dc { struct drm_info_list *debugfs_files;
const struct tegra_dc_soc_info *soc; + + bool has_opp_table; };
static inline struct tegra_dc *