Commit 8aeeb314 authored by Thomas Zimmermann's avatar Thomas Zimmermann
Browse files

drm/mgag200: Provide per-device callbacks for BMC synchronization 



Move the BMC-related code into its own file and wire it up with device
callbacks.

While programming a new display mode, G200EW3 and G200WB have to de-
synchronize with the BMC. Synchronization is done via VIDRST pins
and controlled via VRSTEN and HRSTEN bits. Move the BMC code behind
a serviceable interface and call it from the CRTC's enable and
disable functions.

Signed-off-by: default avatarThomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: default avatarJocelyn Falempe <jfalempe@redhat.com>
Tested-by: default avatarJocelyn Falempe <jfalempe@redhat.com>
Acked-by: default avatarSam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20220728124103.30159-11-tzimmermann@suse.de
parent f639f74a

drivers/gpu/drm/mgag200/Makefile

+1 −0
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0-only

mgag200-y := \

	mgag200_bmc.o \

	mgag200_drv.o \

	mgag200_g200.o \

	mgag200_g200eh.o \

drivers/gpu/drm/mgag200/mgag200_bmc.c

0 → 100644
+99 −0
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// SPDX-License-Identifier: GPL-2.0-only



#include <linux/delay.h>



#include "mgag200_drv.h"



void mgag200_bmc_disable_vidrst(struct mga_device *mdev)

{

	u8 tmp;

	int iter_max;



	/*

	 * 1 - The first step is to inform the BMC of an upcoming mode

	 * change. We are putting the misc<0> to output.

	 */



	WREG8(DAC_INDEX, MGA1064_GEN_IO_CTL);

	tmp = RREG8(DAC_DATA);

	tmp |= 0x10;

	WREG_DAC(MGA1064_GEN_IO_CTL, tmp);



	/* we are putting a 1 on the misc<0> line */

	WREG8(DAC_INDEX, MGA1064_GEN_IO_DATA);

	tmp = RREG8(DAC_DATA);

	tmp |= 0x10;

	WREG_DAC(MGA1064_GEN_IO_DATA, tmp);



	/*

	 * 2- Second step to mask any further scan request. This is

	 * done by asserting the remfreqmsk bit (XSPAREREG<7>)

	 */



	WREG8(DAC_INDEX, MGA1064_SPAREREG);

	tmp = RREG8(DAC_DATA);

	tmp |= 0x80;

	WREG_DAC(MGA1064_SPAREREG, tmp);



	/*

	 * 3a- The third step is to verify if there is an active scan.

	 * We are waiting for a 0 on remhsyncsts <XSPAREREG<0>).

	 */

	iter_max = 300;

	while (!(tmp & 0x1) && iter_max) {

		WREG8(DAC_INDEX, MGA1064_SPAREREG);

		tmp = RREG8(DAC_DATA);

		udelay(1000);

		iter_max--;

	}



	/*

	 * 3b- This step occurs only if the remove is actually

	 * scanning. We are waiting for the end of the frame which is

	 * a 1 on remvsyncsts (XSPAREREG<1>)

	 */

	if (iter_max) {

		iter_max = 300;

		while ((tmp & 0x2) && iter_max) {

			WREG8(DAC_INDEX, MGA1064_SPAREREG);

			tmp = RREG8(DAC_DATA);

			udelay(1000);

			iter_max--;

		}

	}

}



void mgag200_bmc_enable_vidrst(struct mga_device *mdev)

{

	u8 tmp;



	/* Ensure that the vrsten and hrsten are set */

	WREG8(MGAREG_CRTCEXT_INDEX, 1);

	tmp = RREG8(MGAREG_CRTCEXT_DATA);

	WREG8(MGAREG_CRTCEXT_DATA, tmp | 0x88);



	/* Assert rstlvl2 */

	WREG8(DAC_INDEX, MGA1064_REMHEADCTL2);

	tmp = RREG8(DAC_DATA);

	tmp |= 0x8;

	WREG8(DAC_DATA, tmp);



	udelay(10);



	/* Deassert rstlvl2 */

	tmp &= ~0x08;

	WREG8(DAC_INDEX, MGA1064_REMHEADCTL2);

	WREG8(DAC_DATA, tmp);



	/* Remove mask of scan request */

	WREG8(DAC_INDEX, MGA1064_SPAREREG);

	tmp = RREG8(DAC_DATA);

	tmp &= ~0x80;

	WREG8(DAC_DATA, tmp);



	/* Put back a 0 on the misc<0> line */

	WREG8(DAC_INDEX, MGA1064_GEN_IO_DATA);

	tmp = RREG8(DAC_DATA);

	tmp &= ~0x10;

	WREG_DAC(MGA1064_GEN_IO_DATA, tmp);

}

drivers/gpu/drm/mgag200/mgag200_drv.h

+15 −0
Original line number Diff line number Diff line
@@ -263,6 +263,17 @@ struct mgag200_device_info { 
	}



struct mgag200_device_funcs {

	/*

	 * Disables an external reset source (i.e., BMC) before programming

	 * a new display mode.

	 */

	void (*disable_vidrst)(struct mga_device *mdev);



	/*

	 * Enables an external reset source (i.e., BMC) after programming

	 * a new display mode.

	 */

	void (*enable_vidrst)(struct mga_device *mdev);

};



struct mga_device {
@@ -354,6 +365,10 @@ resource_size_t mgag200_device_probe_vram(struct mga_device *mdev); 
void mgag200_init_registers(struct mga_device *mdev);

int mgag200_modeset_init(struct mga_device *mdev, resource_size_t vram_fb_available);



				/* mgag200_bmc.c */

void mgag200_bmc_disable_vidrst(struct mga_device *mdev);

void mgag200_bmc_enable_vidrst(struct mga_device *mdev);



				/* mgag200_i2c.c */

int mgag200_i2c_init(struct mga_device *mdev, struct mga_i2c_chan *i2c);

drivers/gpu/drm/mgag200/mgag200_g200ew3.c

+2 −0
Original line number Diff line number Diff line
@@ -21,6 +21,8 @@ static const struct mgag200_device_info mgag200_g200ew3_device_info = 
	MGAG200_DEVICE_INFO_INIT(2048, 2048, 0, true, 0, 1, false);



static const struct mgag200_device_funcs mgag200_g200ew3_device_funcs = {

	.disable_vidrst = mgag200_bmc_disable_vidrst,

	.enable_vidrst = mgag200_bmc_enable_vidrst,

};



static resource_size_t mgag200_g200ew3_device_probe_vram(struct mga_device *mdev)

drivers/gpu/drm/mgag200/mgag200_g200wb.c

+2 −0
Original line number Diff line number Diff line
@@ -36,6 +36,8 @@ static const struct mgag200_device_info mgag200_g200wb_device_info = 
	MGAG200_DEVICE_INFO_INIT(1280, 1024, 31877, true, 0, 1, false);



static const struct mgag200_device_funcs mgag200_g200wb_device_funcs = {

	.disable_vidrst = mgag200_bmc_disable_vidrst,

	.enable_vidrst = mgag200_bmc_enable_vidrst,

};



struct mga_device *mgag200_g200wb_device_create(struct pci_dev *pdev, const struct drm_driver *drv,