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 | 74 ++++++++++++++++++++++++++++++++++++++ drivers/gpu/drm/tegra/dc.h | 2 ++ 2 files changed, 76 insertions(+)
diff --git a/drivers/gpu/drm/tegra/dc.c b/drivers/gpu/drm/tegra/dc.c index a29d64f87563..d4047a14e2b6 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> @@ -1762,6 +1765,47 @@ 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); + + 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_commit_state(struct tegra_dc *dc, struct tegra_dc_state *state) { @@ -1801,6 +1845,8 @@ static void tegra_dc_commit_state(struct tegra_dc *dc, value = SHIFT_CLK_DIVIDER(state->div) | PIXEL_CLK_DIVIDER_PCD1; tegra_dc_writel(dc, value, DC_DISP_DISP_CLOCK_CONTROL); } + + tegra_dc_update_voltage_state(dc, state); }
static void tegra_dc_stop(struct tegra_dc *dc) @@ -1991,6 +2037,13 @@ 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, @@ -2973,6 +3026,23 @@ 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); @@ -3038,6 +3108,10 @@ 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 40378308d527..871cfb0cd31c 100644 --- a/drivers/gpu/drm/tegra/dc.h +++ b/drivers/gpu/drm/tegra/dc.h @@ -100,6 +100,8 @@ 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 *