diff options
Diffstat (limited to 'drivers/gpu/drm/pl111/pl111_vexpress.c')
| -rw-r--r-- | drivers/gpu/drm/pl111/pl111_vexpress.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/drivers/gpu/drm/pl111/pl111_vexpress.c b/drivers/gpu/drm/pl111/pl111_vexpress.c new file mode 100644 index 000000000..5fa0441bb --- /dev/null +++ b/drivers/gpu/drm/pl111/pl111_vexpress.c @@ -0,0 +1,135 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Versatile Express PL111 handling + * Copyright (C) 2018 Linus Walleij + * + * This module binds to the "arm,vexpress-muxfpga" device on the + * Versatile Express configuration bus and sets up which CLCD instance + * gets muxed out on the DVI bridge. + */ +#include <linux/device.h> +#include <linux/module.h> +#include <linux/regmap.h> +#include <linux/vexpress.h> +#include <linux/platform_device.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_platform.h> +#include "pl111_drm.h" +#include "pl111_vexpress.h" + +#define VEXPRESS_FPGAMUX_MOTHERBOARD 0x00 +#define VEXPRESS_FPGAMUX_DAUGHTERBOARD_1 0x01 +#define VEXPRESS_FPGAMUX_DAUGHTERBOARD_2 0x02 + +int pl111_vexpress_clcd_init(struct device *dev, + struct pl111_drm_dev_private *priv, + struct regmap *map) +{ + struct device_node *root; + struct device_node *child; + struct device_node *ct_clcd = NULL; + bool has_coretile_clcd = false; + bool has_coretile_hdlcd = false; + bool mux_motherboard = true; + u32 val; + int ret; + + /* + * Check if we have a CLCD or HDLCD on the core tile by checking if a + * CLCD or HDLCD is available in the root of the device tree. + */ + root = of_find_node_by_path("/"); + if (!root) + return -EINVAL; + + for_each_available_child_of_node(root, child) { + if (of_device_is_compatible(child, "arm,pl111")) { + has_coretile_clcd = true; + ct_clcd = child; + break; + } + if (of_device_is_compatible(child, "arm,hdlcd")) { + has_coretile_hdlcd = true; + break; + } + } + + /* + * If there is a coretile HDLCD and it has a driver, + * do not mux the CLCD on the motherboard to the DVI. + */ + if (has_coretile_hdlcd && IS_ENABLED(CONFIG_DRM_HDLCD)) + mux_motherboard = false; + + /* + * On the Vexpress CA9 we let the CLCD on the coretile + * take precedence, so also in this case do not mux the + * motherboard to the DVI. + */ + if (has_coretile_clcd) + mux_motherboard = false; + + if (mux_motherboard) { + dev_info(dev, "DVI muxed to motherboard CLCD\n"); + val = VEXPRESS_FPGAMUX_MOTHERBOARD; + } else if (ct_clcd == dev->of_node) { + dev_info(dev, + "DVI muxed to daughterboard 1 (core tile) CLCD\n"); + val = VEXPRESS_FPGAMUX_DAUGHTERBOARD_1; + } else { + dev_info(dev, "core tile graphics present\n"); + dev_info(dev, "this device will be deactivated\n"); + return -ENODEV; + } + + ret = regmap_write(map, 0, val); + if (ret) { + dev_err(dev, "error setting DVI muxmode\n"); + return -ENODEV; + } + + return 0; +} + +/* + * This sets up the regmap pointer that will then be retrieved by + * the detection code in pl111_versatile.c and passed in to the + * pl111_vexpress_clcd_init() function above. + */ +static int vexpress_muxfpga_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct regmap *map; + + map = devm_regmap_init_vexpress_config(&pdev->dev); + if (IS_ERR(map)) + return PTR_ERR(map); + dev_set_drvdata(dev, map); + + return 0; +} + +static const struct of_device_id vexpress_muxfpga_match[] = { + { .compatible = "arm,vexpress-muxfpga", }, + {} +}; + +static struct platform_driver vexpress_muxfpga_driver = { + .driver = { + .name = "vexpress-muxfpga", + .of_match_table = of_match_ptr(vexpress_muxfpga_match), + }, + .probe = vexpress_muxfpga_probe, +}; + +int vexpress_muxfpga_init(void) +{ + int ret; + + ret = platform_driver_register(&vexpress_muxfpga_driver); + /* -EBUSY just means this driver is already registered */ + if (ret == -EBUSY) + ret = 0; + return ret; +} |