[Intel-gfx] [PATCH 02/20] drm/i915/icl: Program DSI Escape clock Divider

[Chauhan, Madhav]

> -----Original Message-----
> From: Zanoni, Paulo R
> Sent: Friday, June 15, 2018 11:00 PM
> To: Chauhan, Madhav <madhav.chauhan at intel.com>; intel-
> gfx at lists.freedesktop.org
> Cc: Nikula, Jani <jani.nikula at intel.com>; Shankar, Uma
> <uma.shankar at intel.com>; Vivi, Rodrigo <rodrigo.vivi at intel.com>
> Subject: Re: [PATCH 02/20] drm/i915/icl: Program DSI Escape clock Divider
> 
> Em Sex, 2018-06-15 às 15:51 +0530, Madhav Chauhan escreveu:
> > Escape Clock is used for LP communication across the DSI Link. To
> > achieve the constant frequency of the escape clock from the variable
> > DPLL frequency output, a variable divider(M) is needed. This patch
> > programs the same.
> >
> > Signed-off-by: Madhav Chauhan <madhav.chauhan at intel.com>
> > ---
> >  drivers/gpu/drm/i915/Makefile        |  1 +
> >  drivers/gpu/drm/i915/i915_reg.h      |  1 +
> >  drivers/gpu/drm/i915/intel_dsi_new.c | 65
> > ++++++++++++++++++++++++++++++++++++
> >  3 files changed, 67 insertions(+)
> >  create mode 100644 drivers/gpu/drm/i915/intel_dsi_new.c
> >
> > diff --git a/drivers/gpu/drm/i915/Makefile
> > b/drivers/gpu/drm/i915/Makefile index 4c6adae..a5f60c8 100644
> > --- a/drivers/gpu/drm/i915/Makefile
> > +++ b/drivers/gpu/drm/i915/Makefile
> > @@ -142,6 +142,7 @@ i915-y += dvo_ch7017.o \
> >  	  intel_dp_mst.o \
> >  	  intel_dp.o \
> >  	  intel_dsi.o \
> > +	  intel_dsi_new.o \
> >  	  intel_dsi_dcs_backlight.o \
> >  	  intel_dsi_pll.o \
> >  	  intel_dsi_vbt.o \
> > diff --git a/drivers/gpu/drm/i915/i915_reg.h
> > b/drivers/gpu/drm/i915/i915_reg.h index bf2d3e4..55ef57d 100644
> > --- a/drivers/gpu/drm/i915/i915_reg.h
> > +++ b/drivers/gpu/drm/i915/i915_reg.h
> > @@ -9350,6 +9350,7 @@ enum skl_power_gate {
> >  						_ICL_DPHY_ESC_CLK_DI
> > V0, \
> >  						_ICL_DPHY_ESC_CLK_DI
> > V1)
> >  #define ICL_ESC_CLK_DIV_MASK		0x1ff
> > +#define DSI_MAX_ESC_CLK			20000
> > /* in KHz */
> >
> >  /* Gen4+ Timestamp and Pipe Frame time stamp registers */
> >  #define GEN4_TIMESTAMP		_MMIO(0x2358)
> > diff --git a/drivers/gpu/drm/i915/intel_dsi_new.c
> > b/drivers/gpu/drm/i915/intel_dsi_new.c
> > new file mode 100644
> > index 0000000..0d325ca
> > --- /dev/null
> > +++ b/drivers/gpu/drm/i915/intel_dsi_new.c
> > @@ -0,0 +1,65 @@
> 
> I am not a lawyer nor a license expert, but as far as I understand (and I may
> be wrong):
> 
> > +// SPDX-License-Identifier: GPL-2.0+
> 
> the line above...

I was getting checkpatch warning and then I explored the options and found this.
Looked at some of the recent files added (intel_hdcp.c) as well and they have this option .

> 
> > +/*
> > + * Copyright © 2018 Intel Corporation
> > + *
> > + * Permission is hereby granted, free of charge, to any person
> > obtaining a
> > + * copy of this software and associated documentation files (the
> > "Software"),
> > + * to deal in the Software without restriction, including without
> > limitation
> > + * the rights to use, copy, modify, merge, publish, distribute,
> > sublicense,
> > + * and/or sell copies of the Software, and to permit persons to whom
> > the
> > + * Software is furnished to do so, subject to the following
> > conditions:
> > + *
> > + * The above copyright notice and this permission notice (including
> > the next
> > + * paragraph) shall be included in all copies or substantial
> > portions of the
> > + * Software.
> > + *
> > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
> KIND,
> > EXPRESS OR
> > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
> > MERCHANTABILITY,
> > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO
> > EVENT SHALL
> > + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
> DAMAGES
> > OR OTHER
> > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
> OTHERWISE,
> > ARISING
> > + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
> OR
> > OTHER
> > + * DEALINGS IN THE SOFTWARE.
> 
> ... does not seem to match the license above.

Can you please be more specific here??

Regards,
Madhav

> 
> https://www.kernel.org/doc/html/latest/process/license-rules.html
> 
> https://spdx.org/
> 
> Thanks,
> Paulo
> 
> > + *
> > + * Authors:
> > + *   Madhav Chauhan <madhav.chauhan at intel.com>
> > + *   Jani Nikula <jani.nikula at intel.com>
> > + */
> > +
> > +#include "intel_dsi.h"
> > +
> > +static void gen11_dsi_program_esc_clk_div(struct intel_encoder
> > *encoder)
> > +{
> > +	struct drm_i915_private *dev_priv = to_i915(encoder-
> > >base.dev);
> > +	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder-
> > >base);
> > +	enum port port;
> > +	u32 bpp = mipi_dsi_pixel_format_to_bpp(intel_dsi-
> > >pixel_format);
> > +	u32 afe_clk_khz; /* 8X Clock */
> > +	u32 esc_clk_div_m;
> > +
> > +	afe_clk_khz = DIV_ROUND_CLOSEST(intel_dsi->pclk * bpp,
> > +					intel_dsi->lane_count);
> > +
> > +	esc_clk_div_m = DIV_ROUND_UP(afe_clk_khz, DSI_MAX_ESC_CLK);
> > +
> > +	for_each_dsi_port(port, intel_dsi->ports) {
> > +		I915_WRITE(ICL_DSI_ESC_CLK_DIV(port),
> > +				esc_clk_div_m &
> > ICL_ESC_CLK_DIV_MASK);
> > +		POSTING_READ(ICL_DSI_ESC_CLK_DIV(port));
> > +	}
> > +
> > +	for_each_dsi_port(port, intel_dsi->ports) {
> > +		I915_WRITE(ICL_DPHY_ESC_CLK_DIV(port),
> > +				esc_clk_div_m &
> > ICL_ESC_CLK_DIV_MASK);
> > +		POSTING_READ(ICL_DPHY_ESC_CLK_DIV(port));
> > +	}
> > +}
> > +
> > +static void __attribute__((unused)) gen11_dsi_pre_enable(
> > +				struct intel_encoder *encoder,
> > +				const struct intel_crtc_state
> > *pipe_config,
> > +				const struct drm_connector_state
> > *conn_state)
> > +{
> > +	/* step3: enable DSI PLL */
> > +	gen11_dsi_program_esc_clk_div(encoder);
> > +}