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

[Paulo Zanoni]

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...

> +/*
> + * 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.

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);
> +}