[Intel-gfx] [PATCH] drm/i915: Enable VLV to work in BIOS-less system
Lee, Chon Ming
chon.ming.lee at intel.com
Fri Sep 13 05:28:51 CEST 2013
On 09/12 18:30, Daniel Vetter wrote:
> On Fri, Sep 13, 2013 at 5:59 AM, Chon Ming Lee <chon.ming.lee at intel.com> wrote:
> > In non PC system, such as IVI, may not use BIOS, instead it uses boot
> > loader with only minimal system initialization. Most of the time, boot
> > loader doesn't come with VBIOS, and depends on device driver to fully
> > initialize the display controller and GPU.
> >
> > For Valleyview, without VBIOS, i915 fails to work. The patch add some
> > missing init code, such as doing a DPIO CMNRESET and program the GMBUS
> > frequency.
> >
> > Signed-off-by: Chon Ming Lee <chon.ming.lee at intel.com>
>
> Generally I prefer patches with tighter topics, grouped into a series.
> For this one I'd split it up into the gmbus setup and the dpio reset,
> so 2 patches.
>
> > ---
> > drivers/gpu/drm/i915/i915_reg.h | 8 +++++
> > drivers/gpu/drm/i915/intel_display.c | 51 ++++++++++++++++++++++++++++++++++
> > 2 files changed, 59 insertions(+), 0 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> > index bcee89b..8ddf58a 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -382,6 +382,8 @@
> > #define FB_FMAX_VMIN_FREQ_LO_MASK 0xf8000000
> >
> > /* vlv2 north clock has */
> > +#define CCK_FUSE_REG 0x8
> > +#define CCK_FUSE_HPLL_FREQ_MASK 0x3
> > #define CCK_REG_DSI_PLL_FUSE 0x44
> > #define CCK_REG_DSI_PLL_CONTROL 0x48
> > #define DSI_PLL_VCO_EN (1 << 31)
> > @@ -1424,6 +1426,12 @@
> >
> > #define MI_ARB_VLV (VLV_DISPLAY_BASE + 0x6504)
> >
> > +#define CZCLK_CDCLK_FREQ_RATIO (dev_priv->info->display_mmio_offset + 0x6508)
> > +#define CDCLK_FREQ_SHIFT 4
> > +#define CDCLK_FREQ_MASK 0x1f
> > +#define CZCLK_FREQ_MASK 0xf
> > +#define GMBUS_FREQ (dev_priv->info->display_mmio_offset + 0x6510)
> > +
> > /*
> > * Palette regs
> > */
> > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> > index 3c0e0cf..9ef1d28 100644
> > --- a/drivers/gpu/drm/i915/intel_display.c
> > +++ b/drivers/gpu/drm/i915/intel_display.c
> > @@ -9497,6 +9497,31 @@ static bool has_edp_a(struct drm_device *dev)
> > return true;
> > }
> >
> > +static void gmbus_set_freq(struct drm_i915_private *dev_priv, u32 hpll_freq)
> > +{
> > + int cdclk_ratio[] = { 10, 15, 20, 25, 30, 0, 40, 45, 50, 0,
> > + 60, 0, 0, 75, 80, 0, 90, 0, 100, 0,
> > + 0, 0, 120, 0, 0, 0, 0, 0, 150, 0, 160 };
> > + int vco_freq[] = { 800, 1600, 2000, 2400 };
> > + int gmbus_freq = 0, cdclk;
> > + u32 reg_val;
> > +
> > + BUG_ON(hpll_freq > ARRAY_SIZE(vco_freq));
> > +
> > + reg_val = I915_READ(CZCLK_CDCLK_FREQ_RATIO);
> > +
> > + cdclk = ((reg_val >> CDCLK_FREQ_SHIFT) & CDCLK_FREQ_MASK) - 1;
> > +
> > + if (cdclk_ratio[cdclk])
> > + gmbus_freq = vco_freq[hpll_freq] / cdclk_ratio[cdclk] * 10;
> > +
> > + WARN_ON(gmbus_freq == 0);
> > +
> > + if (gmbus_freq != 0)
> > + I915_WRITE(GMBUS_FREQ, gmbus_freq);
> > +
> > +}
> > +
> > static void intel_setup_outputs(struct drm_device *dev)
> > {
> > struct drm_i915_private *dev_priv = dev->dev_private;
> > @@ -9555,6 +9580,32 @@ static void intel_setup_outputs(struct drm_device *dev)
>
> Doing this in setup_outputs feels like hiding stuff ;-) I know that
> there's already the pch refclock setup here, but I've just submitted a
> patch to get it out of there.
>
> The problem is that setup_outputs isn't called on resume, and I
> suspect we actually need this.
>
> The dpio reset is probably best stuffed into intel_uncore_sanitize
> > if (I915_READ(PCH_DP_D) & DP_DETECTED)
> > intel_dp_init(dev, PCH_DP_D, PORT_D);
> > } else if (IS_VALLEYVIEW(dev)) {
> > + u32 reg_val;
> > +
> > + /* Trigger DPIO CMN RESET, require especially in BIOS less
> > + * system
> > + */
> > + reg_val = I915_READ(DPIO_CTL);
> > + if (!(reg_val & 0x1)) {
> > + I915_WRITE(DPIO_CTL, 0x0);
> > + I915_WRITE(DPIO_CTL, 0x1);
> > + POSTING_READ(DPIO_CTL);
> > + }
>
> Atm we don't have a suitable "early platform setup" function which is
> called from the right places. I'd shove this into intel_uncore.c:
> intel_uncore_sanitize for now, that should work.
>
> Maybe once your patches are in I'll throw a intel_ealy_init_hw
> refactoring on top to avoid sprinkling things all over the place
> between the driver load and the resume codepaths.
>
I have moved according what you suggest. Now, the system resume is able to work now.
Will send out the revise patch.
> > +
> > + /* In BIOS-less system, program the correct gmbus frequency
> > + * before reading edid.
> > + */
> > +
> > + /* Obtain SKU information to determine the correct CDCLK */
> > + mutex_lock(&dev_priv->dpio_lock);
> > + reg_val = vlv_cck_read(dev_priv, CCK_FUSE_REG);
> > + mutex_unlock(&dev_priv->dpio_lock);
>
> I'd move this into the gmbus_freq setup function.
>
> > +
> > + reg_val &= CCK_FUSE_HPLL_FREQ_MASK;
> > +
> > + /* Write CDCLK to GMBUS freq for GMBUS clk generation. */
> > + gmbus_set_freq(dev_priv, reg_val);
>
> Imo it's better to move this to intel_i2c.c: intel_i2c_reset. That
> function is already called from all the right places.
>
> Cheers, Daniel
>
> > +
> > /* Check for built-in panel first. Shares lanes with HDMI on SDVOC */
> > if (I915_READ(VLV_DISPLAY_BASE + GEN4_HDMIC) & SDVO_DETECTED) {
> > intel_hdmi_init(dev, VLV_DISPLAY_BASE + GEN4_HDMIC,
> > --
> > 1.7.7.6
> >
> > _______________________________________________
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> > Intel-gfx at lists.freedesktop.org
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>
>
>
> --
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch
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