// SPDX-License-Identifier: MIT /* * Copyright © 2021 Intel Corporation */ #include "i915_reg.h" #include "intel_de.h" #include "intel_display_types.h" #include "intel_panel.h" #include "intel_pch_refclk.h" #include "intel_sbi.h" static void lpt_fdi_reset_mphy(struct drm_i915_private *dev_priv) { u32 tmp; tmp = intel_de_read(dev_priv, SOUTH_CHICKEN2); tmp |= FDI_MPHY_IOSFSB_RESET_CTL; intel_de_write(dev_priv, SOUTH_CHICKEN2, tmp); if (wait_for_us(intel_de_read(dev_priv, SOUTH_CHICKEN2) & FDI_MPHY_IOSFSB_RESET_STATUS, 100)) drm_err(&dev_priv->drm, "FDI mPHY reset assert timeout\n"); tmp = intel_de_read(dev_priv, SOUTH_CHICKEN2); tmp &= ~FDI_MPHY_IOSFSB_RESET_CTL; intel_de_write(dev_priv, SOUTH_CHICKEN2, tmp); if (wait_for_us((intel_de_read(dev_priv, SOUTH_CHICKEN2) & FDI_MPHY_IOSFSB_RESET_STATUS) == 0, 100)) drm_err(&dev_priv->drm, "FDI mPHY reset de-assert timeout\n"); } /* WaMPhyProgramming:hsw */ static void lpt_fdi_program_mphy(struct drm_i915_private *dev_priv) { u32 tmp; lpt_fdi_reset_mphy(dev_priv); tmp = intel_sbi_read(dev_priv, 0x8008, SBI_MPHY); tmp &= ~(0xFF << 24); tmp |= (0x12 << 24); intel_sbi_write(dev_priv, 0x8008, tmp, SBI_MPHY); tmp = intel_sbi_read(dev_priv, 0x2008, SBI_MPHY); tmp |= (1 << 11); intel_sbi_write(dev_priv, 0x2008, tmp, SBI_MPHY); tmp = intel_sbi_read(dev_priv, 0x2108, SBI_MPHY); tmp |= (1 << 11); intel_sbi_write(dev_priv, 0x2108, tmp, SBI_MPHY); tmp = intel_sbi_read(dev_priv, 0x206C, SBI_MPHY); tmp |= (1 << 24) | (1 << 21) | (1 << 18); intel_sbi_write(dev_priv, 0x206C, tmp, SBI_MPHY); tmp = intel_sbi_read(dev_priv, 0x216C, SBI_MPHY); tmp |= (1 << 24) | (1 << 21) | (1 << 18); intel_sbi_write(dev_priv, 0x216C, tmp, SBI_MPHY); tmp = intel_sbi_read(dev_priv, 0x2080, SBI_MPHY); tmp &= ~(7 << 13); tmp |= (5 << 13); intel_sbi_write(dev_priv, 0x2080, tmp, SBI_MPHY); tmp = intel_sbi_read(dev_priv, 0x2180, SBI_MPHY); tmp &= ~(7 << 13); tmp |= (5 << 13); intel_sbi_write(dev_priv, 0x2180, tmp, SBI_MPHY); tmp = intel_sbi_read(dev_priv, 0x208C, SBI_MPHY); tmp &= ~0xFF; tmp |= 0x1C; intel_sbi_write(dev_priv, 0x208C, tmp, SBI_MPHY); tmp = intel_sbi_read(dev_priv, 0x218C, SBI_MPHY); tmp &= ~0xFF; tmp |= 0x1C; intel_sbi_write(dev_priv, 0x218C, tmp, SBI_MPHY); tmp = intel_sbi_read(dev_priv, 0x2098, SBI_MPHY); tmp &= ~(0xFF << 16); tmp |= (0x1C << 16); intel_sbi_write(dev_priv, 0x2098, tmp, SBI_MPHY); tmp = intel_sbi_read(dev_priv, 0x2198, SBI_MPHY); tmp &= ~(0xFF << 16); tmp |= (0x1C << 16); intel_sbi_write(dev_priv, 0x2198, tmp, SBI_MPHY); tmp = intel_sbi_read(dev_priv, 0x20C4, SBI_MPHY); tmp |= (1 << 27); intel_sbi_write(dev_priv, 0x20C4, tmp, SBI_MPHY); tmp = intel_sbi_read(dev_priv, 0x21C4, SBI_MPHY); tmp |= (1 << 27); intel_sbi_write(dev_priv, 0x21C4, tmp, SBI_MPHY); tmp = intel_sbi_read(dev_priv, 0x20EC, SBI_MPHY); tmp &= ~(0xF << 28); tmp |= (4 << 28); intel_sbi_write(dev_priv, 0x20EC, tmp, SBI_MPHY); tmp = intel_sbi_read(dev_priv, 0x21EC, SBI_MPHY); tmp &= ~(0xF << 28); tmp |= (4 << 28); intel_sbi_write(dev_priv, 0x21EC, tmp, SBI_MPHY); } void lpt_disable_iclkip(struct drm_i915_private *dev_priv) { u32 temp; intel_de_write(dev_priv, PIXCLK_GATE, PIXCLK_GATE_GATE); mutex_lock(&dev_priv->sb_lock); temp = intel_sbi_read(dev_priv, SBI_SSCCTL6, SBI_ICLK); temp |= SBI_SSCCTL_DISABLE; intel_sbi_write(dev_priv, SBI_SSCCTL6, temp, SBI_ICLK); mutex_unlock(&dev_priv->sb_lock); } struct iclkip_params { u32 iclk_virtual_root_freq; u32 iclk_pi_range; u32 divsel, phaseinc, auxdiv, phasedir, desired_divisor; }; static void iclkip_params_init(struct iclkip_params *p) { memset(p, 0, sizeof(*p)); p->iclk_virtual_root_freq = 172800 * 1000; p->iclk_pi_range = 64; } static int lpt_iclkip_freq(struct iclkip_params *p) { return DIV_ROUND_CLOSEST(p->iclk_virtual_root_freq, p->desired_divisor << p->auxdiv); } static void lpt_compute_iclkip(struct iclkip_params *p, int clock) { iclkip_params_init(p); /* The iCLK virtual clock root frequency is in MHz, * but the adjusted_mode->crtc_clock in KHz. To get the * divisors, it is necessary to divide one by another, so we * convert the virtual clock precision to KHz here for higher * precision. */ for (p->auxdiv = 0; p->auxdiv < 2; p->auxdiv++) { p->desired_divisor = DIV_ROUND_CLOSEST(p->iclk_virtual_root_freq, clock << p->auxdiv); p->divsel = (p->desired_divisor / p->iclk_pi_range) - 2; p->phaseinc = p->desired_divisor % p->iclk_pi_range; /* * Near 20MHz is a corner case which is * out of range for the 7-bit divisor */ if (p->divsel <= 0x7f) break; } } int lpt_iclkip(const struct intel_crtc_state *crtc_state) { struct iclkip_params p; lpt_compute_iclkip(&p, crtc_state->hw.adjusted_mode.crtc_clock); return lpt_iclkip_freq(&p); } /* Program iCLKIP clock to the desired frequency */ void lpt_program_iclkip(const struct intel_crtc_state *crtc_state) { struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc); struct drm_i915_private *dev_priv = to_i915(crtc->base.dev); int clock = crtc_state->hw.adjusted_mode.crtc_clock; struct iclkip_params p; u32 temp; lpt_disable_iclkip(dev_priv); lpt_compute_iclkip(&p, clock); drm_WARN_ON(&dev_priv->drm, lpt_iclkip_freq(&p) != clock); /* This should not happen with any sane values */ drm_WARN_ON(&dev_priv->drm, SBI_SSCDIVINTPHASE_DIVSEL(p.divsel) & ~SBI_SSCDIVINTPHASE_DIVSEL_MASK); drm_WARN_ON(&dev_priv->drm, SBI_SSCDIVINTPHASE_DIR(p.phasedir) & ~SBI_SSCDIVINTPHASE_INCVAL_MASK); drm_dbg_kms(&dev_priv->drm, "iCLKIP clock: found settings for %dKHz refresh rate: auxdiv=%x, divsel=%x, phasedir=%x, phaseinc=%x\n", clock, p.auxdiv, p.divsel, p.phasedir, p.phaseinc); mutex_lock(&dev_priv->sb_lock); /* Program SSCDIVINTPHASE6 */ temp = intel_sbi_read(dev_priv, SBI_SSCDIVINTPHASE6, SBI_ICLK); temp &= ~SBI_SSCDIVINTPHASE_DIVSEL_MASK; temp |= SBI_SSCDIVINTPHASE_DIVSEL(p.divsel); temp &= ~SBI_SSCDIVINTPHASE_INCVAL_MASK; temp |= SBI_SSCDIVINTPHASE_INCVAL(p.phaseinc); temp |= SBI_SSCDIVINTPHASE_DIR(p.phasedir); temp |= SBI_SSCDIVINTPHASE_PROPAGATE; intel_sbi_write(dev_priv, SBI_SSCDIVINTPHASE6, temp, SBI_ICLK); /* Program SSCAUXDIV */ temp = intel_sbi_read(dev_priv, SBI_SSCAUXDIV6, SBI_ICLK); temp &= ~SBI_SSCAUXDIV_FINALDIV2SEL(1); temp |= SBI_SSCAUXDIV_FINALDIV2SEL(p.auxdiv); intel_sbi_write(dev_priv, SBI_SSCAUXDIV6, temp, SBI_ICLK); /* Enable modulator and associated divider */ temp = intel_sbi_read(dev_priv, SBI_SSCCTL6, SBI_ICLK); temp &= ~SBI_SSCCTL_DISABLE; intel_sbi_write(dev_priv, SBI_SSCCTL6, temp, SBI_ICLK); mutex_unlock(&dev_priv->sb_lock); /* Wait for initialization time */ udelay(24); intel_de_write(dev_priv, PIXCLK_GATE, PIXCLK_GATE_UNGATE); } int lpt_get_iclkip(struct drm_i915_private *dev_priv) { struct iclkip_params p; u32 temp; if ((intel_de_read(dev_priv, PIXCLK_GATE) & PIXCLK_GATE_UNGATE) == 0) return 0; iclkip_params_init(&p); mutex_lock(&dev_priv->sb_lock); temp = intel_sbi_read(dev_priv, SBI_SSCCTL6, SBI_ICLK); if (temp & SBI_SSCCTL_DISABLE) { mutex_unlock(&dev_priv->sb_lock); return 0; } temp = intel_sbi_read(dev_priv, SBI_SSCDIVINTPHASE6, SBI_ICLK); p.divsel = (temp & SBI_SSCDIVINTPHASE_DIVSEL_MASK) >> SBI_SSCDIVINTPHASE_DIVSEL_SHIFT; p.phaseinc = (temp & SBI_SSCDIVINTPHASE_INCVAL_MASK) >> SBI_SSCDIVINTPHASE_INCVAL_SHIFT; temp = intel_sbi_read(dev_priv, SBI_SSCAUXDIV6, SBI_ICLK); p.auxdiv = (temp & SBI_SSCAUXDIV_FINALDIV2SEL_MASK) >> SBI_SSCAUXDIV_FINALDIV2SEL_SHIFT; mutex_unlock(&dev_priv->sb_lock); p.desired_divisor = (p.divsel + 2) * p.iclk_pi_range + p.phaseinc; return lpt_iclkip_freq(&p); } /* Implements 3 different sequences from BSpec chapter "Display iCLK * Programming" based on the parameters passed: * - Sequence to enable CLKOUT_DP * - Sequence to enable CLKOUT_DP without spread * - Sequence to enable CLKOUT_DP for FDI usage and configure PCH FDI I/O */ static void lpt_enable_clkout_dp(struct drm_i915_private *dev_priv, bool with_spread, bool with_fdi) { u32 reg, tmp; if (drm_WARN(&dev_priv->drm, with_fdi && !with_spread, "FDI requires downspread\n")) with_spread = true; if (drm_WARN(&dev_priv->drm, HAS_PCH_LPT_LP(dev_priv) && with_fdi, "LP PCH doesn't have FDI\n")) with_fdi = false; mutex_lock(&dev_priv->sb_lock); tmp = intel_sbi_read(dev_priv, SBI_SSCCTL, SBI_ICLK); tmp &= ~SBI_SSCCTL_DISABLE; tmp |= SBI_SSCCTL_PATHALT; intel_sbi_write(dev_priv, SBI_SSCCTL, tmp, SBI_ICLK); udelay(24); if (with_spread) { tmp = intel_sbi_read(dev_priv, SBI_SSCCTL, SBI_ICLK); tmp &= ~SBI_SSCCTL_PATHALT; intel_sbi_write(dev_priv, SBI_SSCCTL, tmp, SBI_ICLK); if (with_fdi) lpt_fdi_program_mphy(dev_priv); } reg = HAS_PCH_LPT_LP(dev_priv) ? SBI_GEN0 : SBI_DBUFF0; tmp = intel_sbi_read(dev_priv, reg, SBI_ICLK); tmp |= SBI_GEN0_CFG_BUFFENABLE_DISABLE; intel_sbi_write(dev_priv, reg, tmp, SBI_ICLK); mutex_unlock(&dev_priv->sb_lock); } /* Sequence to disable CLKOUT_DP */ void lpt_disable_clkout_dp(struct drm_i915_private *dev_priv) { u32 reg, tmp; mutex_lock(&dev_priv->sb_lock); reg = HAS_PCH_LPT_LP(dev_priv) ? SBI_GEN0 : SBI_DBUFF0; tmp = intel_sbi_read(dev_priv, reg, SBI_ICLK); tmp &= ~SBI_GEN0_CFG_BUFFENABLE_DISABLE; intel_sbi_write(dev_priv, reg, tmp, SBI_ICLK); tmp = intel_sbi_read(dev_priv, SBI_SSCCTL, SBI_ICLK); if (!(tmp & SBI_SSCCTL_DISABLE)) { if (!(tmp & SBI_SSCCTL_PATHALT)) { tmp |= SBI_SSCCTL_PATHALT; intel_sbi_write(dev_priv, SBI_SSCCTL, tmp, SBI_ICLK); udelay(32); } tmp |= SBI_SSCCTL_DISABLE; intel_sbi_write(dev_priv, SBI_SSCCTL, tmp, SBI_ICLK); } mutex_unlock(&dev_priv->sb_lock); } #define BEND_IDX(steps) ((50 + (steps)) / 5) static const u16 sscdivintphase[] = { [BEND_IDX( 50)] = 0x3B23, [BEND_IDX( 45)] = 0x3B23, [BEND_IDX( 40)] = 0x3C23, [BEND_IDX( 35)] = 0x3C23, [BEND_IDX( 30)] = 0x3D23, [BEND_IDX( 25)] = 0x3D23, [BEND_IDX( 20)] = 0x3E23, [BEND_IDX( 15)] = 0x3E23, [BEND_IDX( 10)] = 0x3F23, [BEND_IDX( 5)] = 0x3F23, [BEND_IDX( 0)] = 0x0025, [BEND_IDX( -5)] = 0x0025, [BEND_IDX(-10)] = 0x0125, [BEND_IDX(-15)] = 0x0125, [BEND_IDX(-20)] = 0x0225, [BEND_IDX(-25)] = 0x0225, [BEND_IDX(-30)] = 0x0325, [BEND_IDX(-35)] = 0x0325, [BEND_IDX(-40)] = 0x0425, [BEND_IDX(-45)] = 0x0425, [BEND_IDX(-50)] = 0x0525, }; /* * Bend CLKOUT_DP * steps -50 to 50 inclusive, in steps of 5 * < 0 slow down the clock, > 0 speed up the clock, 0 == no bend (135MHz) * change in clock period = -(steps / 10) * 5.787 ps */ static void lpt_bend_clkout_dp(struct drm_i915_private *dev_priv, int steps) { u32 tmp; int idx = BEND_IDX(steps); if (drm_WARN_ON(&dev_priv->drm, steps % 5 != 0)) return; if (drm_WARN_ON(&dev_priv->drm, idx >= ARRAY_SIZE(sscdivintphase))) return; mutex_lock(&dev_priv->sb_lock); if (steps % 10 != 0) tmp = 0xAAAAAAAB; else tmp = 0x00000000; intel_sbi_write(dev_priv, SBI_SSCDITHPHASE, tmp, SBI_ICLK); tmp = intel_sbi_read(dev_priv, SBI_SSCDIVINTPHASE, SBI_ICLK); tmp &= 0xffff0000; tmp |= sscdivintphase[idx]; intel_sbi_write(dev_priv, SBI_SSCDIVINTPHASE, tmp, SBI_ICLK); mutex_unlock(&dev_priv->sb_lock); } #undef BEND_IDX static bool spll_uses_pch_ssc(struct drm_i915_private *dev_priv) { u32 fuse_strap = intel_de_read(dev_priv, FUSE_STRAP); u32 ctl = intel_de_read(dev_priv, SPLL_CTL); if ((ctl & SPLL_PLL_ENABLE) == 0) return false; if ((ctl & SPLL_REF_MASK) == SPLL_REF_MUXED_SSC && (fuse_strap & HSW_CPU_SSC_ENABLE) == 0) return true; if (IS_BROADWELL(dev_priv) && (ctl & SPLL_REF_MASK) == SPLL_REF_PCH_SSC_BDW) return true; return false; } static bool wrpll_uses_pch_ssc(struct drm_i915_private *dev_priv, enum intel_dpll_id id) { u32 fuse_strap = intel_de_read(dev_priv, FUSE_STRAP); u32 ctl = intel_de_read(dev_priv, WRPLL_CTL(id)); if ((ctl & WRPLL_PLL_ENABLE) == 0) return false; if ((ctl & WRPLL_REF_MASK) == WRPLL_REF_PCH_SSC) return true; if ((IS_BROADWELL(dev_priv) || IS_HSW_ULT(dev_priv)) && (ctl & WRPLL_REF_MASK) == WRPLL_REF_MUXED_SSC_BDW && (fuse_strap & HSW_CPU_SSC_ENABLE) == 0) return true; return false; } static void lpt_init_pch_refclk(struct drm_i915_private *dev_priv) { struct intel_encoder *encoder; bool has_fdi = false; for_each_intel_encoder(&dev_priv->drm, encoder) { switch (encoder->type) { case INTEL_OUTPUT_ANALOG: has_fdi = true; break; default: break; } } /* * The BIOS may have decided to use the PCH SSC * reference so we must not disable it until the * relevant PLLs have stopped relying on it. We'll * just leave the PCH SSC reference enabled in case * any active PLL is using it. It will get disabled * after runtime suspend if we don't have FDI. * * TODO: Move the whole reference clock handling * to the modeset sequence proper so that we can * actually enable/disable/reconfigure these things * safely. To do that we need to introduce a real * clock hierarchy. That would also allow us to do * clock bending finally. */ dev_priv->pch_ssc_use = 0; if (spll_uses_pch_ssc(dev_priv)) { drm_dbg_kms(&dev_priv->drm, "SPLL using PCH SSC\n"); dev_priv->pch_ssc_use |= BIT(DPLL_ID_SPLL); } if (wrpll_uses_pch_ssc(dev_priv, DPLL_ID_WRPLL1)) { drm_dbg_kms(&dev_priv->drm, "WRPLL1 using PCH SSC\n"); dev_priv->pch_ssc_use |= BIT(DPLL_ID_WRPLL1); } if (wrpll_uses_pch_ssc(dev_priv, DPLL_ID_WRPLL2)) { drm_dbg_kms(&dev_priv->drm, "WRPLL2 using PCH SSC\n"); dev_priv->pch_ssc_use |= BIT(DPLL_ID_WRPLL2); } if (dev_priv->pch_ssc_use) return; if (has_fdi) { lpt_bend_clkout_dp(dev_priv, 0); lpt_enable_clkout_dp(dev_priv, true, true); } else { lpt_disable_clkout_dp(dev_priv); } } static void ilk_init_pch_refclk(struct drm_i915_private *dev_priv) { struct intel_encoder *encoder; int i; u32 val, final; bool has_lvds = false; bool has_cpu_edp = false; bool has_panel = false; bool has_ck505 = false; bool can_ssc = false; bool using_ssc_source = false; /* We need to take the global config into account */ for_each_intel_encoder(&dev_priv->drm, encoder) { switch (encoder->type) { case INTEL_OUTPUT_LVDS: has_panel = true; has_lvds = true; break; case INTEL_OUTPUT_EDP: has_panel = true; if (encoder->port == PORT_A) has_cpu_edp = true; break; default: break; } } if (HAS_PCH_IBX(dev_priv)) { has_ck505 = dev_priv->display.vbt.display_clock_mode; can_ssc = has_ck505; } else { has_ck505 = false; can_ssc = true; } /* Check if any DPLLs are using the SSC source */ for (i = 0; i < dev_priv->display.dpll.num_shared_dpll; i++) { u32 temp = intel_de_read(dev_priv, PCH_DPLL(i)); if (!(temp & DPLL_VCO_ENABLE)) continue; if ((temp & PLL_REF_INPUT_MASK) == PLLB_REF_INPUT_SPREADSPECTRUMIN) { using_ssc_source = true; break; } } drm_dbg_kms(&dev_priv->drm, "has_panel %d has_lvds %d has_ck505 %d using_ssc_source %d\n", has_panel, has_lvds, has_ck505, using_ssc_source); /* Ironlake: try to setup display ref clock before DPLL * enabling. This is only under driver's control after * PCH B stepping, previous chipset stepping should be * ignoring this setting. */ val = intel_de_read(dev_priv, PCH_DREF_CONTROL); /* As we must carefully and slowly disable/enable each source in turn, * compute the final state we want first and check if we need to * make any changes at all. */ final = val; final &= ~DREF_NONSPREAD_SOURCE_MASK; if (has_ck505) final |= DREF_NONSPREAD_CK505_ENABLE; else final |= DREF_NONSPREAD_SOURCE_ENABLE; final &= ~DREF_SSC_SOURCE_MASK; final &= ~DREF_CPU_SOURCE_OUTPUT_MASK; final &= ~DREF_SSC1_ENABLE; if (has_panel) { final |= DREF_SSC_SOURCE_ENABLE; if (intel_panel_use_ssc(dev_priv) && can_ssc) final |= DREF_SSC1_ENABLE; if (has_cpu_edp) { if (intel_panel_use_ssc(dev_priv) && can_ssc) final |= DREF_CPU_SOURCE_OUTPUT_DOWNSPREAD; else final |= DREF_CPU_SOURCE_OUTPUT_NONSPREAD; } else { final |= DREF_CPU_SOURCE_OUTPUT_DISABLE; } } else if (using_ssc_source) { final |= DREF_SSC_SOURCE_ENABLE; final |= DREF_SSC1_ENABLE; } if (final == val) return; /* Always enable nonspread source */ val &= ~DREF_NONSPREAD_SOURCE_MASK; if (has_ck505) val |= DREF_NONSPREAD_CK505_ENABLE; else val |= DREF_NONSPREAD_SOURCE_ENABLE; if (has_panel) { val &= ~DREF_SSC_SOURCE_MASK; val |= DREF_SSC_SOURCE_ENABLE; /* SSC must be turned on before enabling the CPU output */ if (intel_panel_use_ssc(dev_priv) && can_ssc) { drm_dbg_kms(&dev_priv->drm, "Using SSC on panel\n"); val |= DREF_SSC1_ENABLE; } else { val &= ~DREF_SSC1_ENABLE; } /* Get SSC going before enabling the outputs */ intel_de_write(dev_priv, PCH_DREF_CONTROL, val); intel_de_posting_read(dev_priv, PCH_DREF_CONTROL); udelay(200); val &= ~DREF_CPU_SOURCE_OUTPUT_MASK; /* Enable CPU source on CPU attached eDP */ if (has_cpu_edp) { if (intel_panel_use_ssc(dev_priv) && can_ssc) { drm_dbg_kms(&dev_priv->drm, "Using SSC on eDP\n"); val |= DREF_CPU_SOURCE_OUTPUT_DOWNSPREAD; } else { val |= DREF_CPU_SOURCE_OUTPUT_NONSPREAD; } } else { val |= DREF_CPU_SOURCE_OUTPUT_DISABLE; } intel_de_write(dev_priv, PCH_DREF_CONTROL, val); intel_de_posting_read(dev_priv, PCH_DREF_CONTROL); udelay(200); } else { drm_dbg_kms(&dev_priv->drm, "Disabling CPU source output\n"); val &= ~DREF_CPU_SOURCE_OUTPUT_MASK; /* Turn off CPU output */ val |= DREF_CPU_SOURCE_OUTPUT_DISABLE; intel_de_write(dev_priv, PCH_DREF_CONTROL, val); intel_de_posting_read(dev_priv, PCH_DREF_CONTROL); udelay(200); if (!using_ssc_source) { drm_dbg_kms(&dev_priv->drm, "Disabling SSC source\n"); /* Turn off the SSC source */ val &= ~DREF_SSC_SOURCE_MASK; val |= DREF_SSC_SOURCE_DISABLE; /* Turn off SSC1 */ val &= ~DREF_SSC1_ENABLE; intel_de_write(dev_priv, PCH_DREF_CONTROL, val); intel_de_posting_read(dev_priv, PCH_DREF_CONTROL); udelay(200); } } drm_WARN_ON(&dev_priv->drm, val != final); } /* * Initialize reference clocks when the driver loads */ void intel_init_pch_refclk(struct drm_i915_private *dev_priv) { if (HAS_PCH_IBX(dev_priv) || HAS_PCH_CPT(dev_priv)) ilk_init_pch_refclk(dev_priv); else if (HAS_PCH_LPT(dev_priv)) lpt_init_pch_refclk(dev_priv); }