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Unverified Commit 8818e865 authored by Icenowy Zheng's avatar Icenowy Zheng Committed by Maxime Ripard
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bus: add bus driver for accessing Allwinner A64 DE2 



The "Display Engine 2.0" (usually called DE2) on the Allwinner A64 SoC
is different from the ones on other Allwinner SoCs. It requires a SRAM
region to be claimed, otherwise all DE2 subblocks won't be accessible.

Add a bus driver for the Allwinner A64 DE2 part which claims the SRAM
region when probing.

Signed-off-by: default avatarIcenowy Zheng <icenowy@aosc.io>
Signed-off-by: default avatarMaxime Ripard <maxime.ripard@bootlin.com>
parent a6e3ab0b

drivers/bus/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -103,6 +103,16 @@ config SIMPLE_PM_BUS 
	  Controller (BSC, sometimes called "LBSC within Bus Bridge", or

	  "External Bus Interface") as found on several Renesas ARM SoCs.



config SUN50I_DE2_BUS

	bool "Allwinner A64 DE2 Bus Driver"

	  default ARM64

	  depends on ARCH_SUNXI

	  select SUNXI_SRAM

	  help

	  Say y here to enable support for Allwinner A64 DE2 bus driver. It's

	  mostly transparent, but a SRAM region needs to be claimed in the SRAM

	  controller to make the all blocks in the DE2 part accessible.



config SUNXI_RSB

	tristate "Allwinner sunXi Reduced Serial Bus Driver"

	  default MACH_SUN8I || MACH_SUN9I || ARM64

drivers/bus/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ obj-$(CONFIG_OMAP_INTERCONNECT) += omap_l3_smx.o omap_l3_noc.o 


obj-$(CONFIG_OMAP_OCP2SCP)	+= omap-ocp2scp.o

obj-$(CONFIG_QCOM_EBI2)		+= qcom-ebi2.o

obj-$(CONFIG_SUN50I_DE2_BUS)	+= sun50i-de2.o

obj-$(CONFIG_SUNXI_RSB)		+= sunxi-rsb.o

obj-$(CONFIG_SIMPLE_PM_BUS)	+= simple-pm-bus.o

obj-$(CONFIG_TEGRA_ACONNECT)	+= tegra-aconnect.o

drivers/bus/sun50i-de2.c

0 → 100644
+48 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * Allwinner A64 Display Engine 2.0 Bus Driver

 *

 * Copyright (C) 2018 Icenowy Zheng <icenowy@aosc.io>

 */



#include <linux/of_platform.h>

#include <linux/platform_device.h>

#include <linux/soc/sunxi/sunxi_sram.h>



static int sun50i_de2_bus_probe(struct platform_device *pdev)

{

	struct device_node *np = pdev->dev.of_node;

	int ret;



	ret = sunxi_sram_claim(&pdev->dev);

	if (ret) {

		dev_err(&pdev->dev, "Error couldn't map SRAM to device\n");

		return ret;

	}



	of_platform_populate(np, NULL, NULL, &pdev->dev);



	return 0;

}



static int sun50i_de2_bus_remove(struct platform_device *pdev)

{

	sunxi_sram_release(&pdev->dev);

	return 0;

}



static const struct of_device_id sun50i_de2_bus_of_match[] = {

	{ .compatible = "allwinner,sun50i-a64-de2", },

	{ /* sentinel */ }

};



static struct platform_driver sun50i_de2_bus_driver = {

	.probe = sun50i_de2_bus_probe,

	.remove = sun50i_de2_bus_remove,

	.driver = {

		.name = "sun50i-de2-bus",

		.of_match_table = sun50i_de2_bus_of_match,

	},

};



builtin_platform_driver(sun50i_de2_bus_driver);