// SPDX-License-Identifier: GPL-2.0+
// Copyright 2018 IBM Corporation
#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/irq.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/of_reserved_mem.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/reset.h>
#include <drm/drm_atomic_helper.h>
#include <drm/drm_device.h>
#include <drm/drm_fbdev_dma.h>
#include <drm/drm_gem_dma_helper.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_module.h>
#include <drm/drm_probe_helper.h>
#include <drm/drm_simple_kms_helper.h>
#include <drm/drm_vblank.h>
#include <drm/drm_drv.h>
#include "aspeed_gfx.h"
/**
* DOC: ASPEED GFX Driver
*
* This driver is for the ASPEED BMC SoC's 'GFX' display hardware, also called
* the 'SOC Display Controller' in the datasheet. This driver runs on the ARM
* based BMC systems, unlike the ast driver which runs on a host CPU and is for
* a PCIe graphics device.
*
* The AST2500 supports a total of 3 output paths:
*
* 1. VGA output, the output target can choose either or both to the DAC
* or DVO interface.
*
* 2. Graphics CRT output, the output target can choose either or both to
* the DAC or DVO interface.
*
* 3. Video input from DVO, the video input can be used for video engine
* capture or DAC display output.
*
* Output options are selected in SCU2C.
*
* The "VGA mode" device is the PCI attached controller. The "Graphics CRT"
* is the ARM's internal display controller.
*
* The driver only supports a simple configuration consisting of a 40MHz
* pixel clock, fixed by hardware limitations, and the VGA output path.
*
* The driver was written with the 'AST2500 Software Programming Guide' v17,
* which is available under NDA from ASPEED.
*/
struct aspeed_gfx_config {
u32 dac_reg; /* DAC register in SCU */
u32 int_clear_reg; /* Interrupt clear register */
u32 vga_scratch_reg; /* VGA scratch register in SCU */
u32 throd_val; /* Default Threshold Seting */
u32 scan_line_max; /* Max memory size of one scan line */
};
static const struct aspeed_gfx_config ast2400_config = {
.dac_reg = 0x2c,
.int_clear_reg = 0x60,
.vga_scratch_reg = 0x50,
.throd_val = CRT_THROD_LOW(0x1e) | CRT_THROD_HIGH(0x12),
.scan_line_max = 64,
};
static const struct aspeed_gfx_config ast2500_config = {
.dac_reg = 0x2c,
.int_clear_reg = 0x60,
.vga_scratch_reg = 0x50,
.throd_val = CRT_THROD_LOW(0x24) | CRT_THROD_HIGH(0x3c),
.scan_line_max = 128,
};
static const struct aspeed_gfx_config ast2600_config = {
.dac_reg = 0xc0,
.int_clear_reg = 0x68,
.vga_scratch_reg = 0x50,
.throd_val = CRT_THROD_LOW(0x50) | CRT_THROD_HIGH(0x70),
.scan_line_max = 128,
};
static const struct of_device_id aspeed_gfx_match[] = {
{ .compatible = "aspeed,ast2400-gfx", .data = &ast2400_config },
{ .compatible = "aspeed,ast2500-gfx", .data = &ast2500_config },
{ .compatible = "aspeed,ast2600-gfx", .data = &ast2600_config },
{ },
};
MODULE_DEVICE_TABLE(of, aspeed_gfx_match);
static const struct drm_mode_config_funcs aspeed_gfx_mode_config_funcs = {
.fb_create = drm_gem_fb_create,
.atomic_check = drm_atomic_helper_check,
.atomic_commit = drm_atomic_helper_commit,
};
static int aspeed_gfx_setup_mode_config(struct drm_device *drm)
{
int ret;
ret = drmm_mode_config_init(drm);
if (ret)
return ret;
drm->mode_config.min_width = 0;
drm->mode_config.min_height = 0;
drm->mode_config.max_width = 800;
drm->mode_config.max_height = 600;
drm->mode_config.funcs = &aspeed_gfx_mode_config_funcs;
return ret;
}
static irqreturn_t aspeed_gfx_irq_handler(int irq, void *data)
{
struct drm_device *drm = data;
struct aspeed_gfx *priv = to_aspeed_gfx(drm);
u32 reg;
reg = readl(priv->base + CRT_CTRL1);
if (reg & CRT_CTRL_VERTICAL_INTR_STS) {
drm_crtc_handle_vblank(&priv->pipe.crtc);
writel(reg, priv->base + priv->int_clr_reg);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
static int aspeed_gfx_load(struct drm_device *drm)
{
struct platform_device *pdev = to_platform_device(drm->dev);
struct aspeed_gfx *priv = to_aspeed_gfx(drm);
struct device_node *np = pdev->dev.of_node;
const struct aspeed_gfx_config *config;
struct resource *res;
int ret;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
priv->base = devm_ioremap_resource(drm->dev, res);
if (IS_ERR(priv->base))
return PTR_ERR(priv->base);
config = device_get_match_data(&pdev->dev);
if (!config)
return -EINVAL;
priv->dac_reg = config->dac_reg;
priv->int_clr_reg = config->int_clear_reg;
priv->vga_scratch_reg = config->vga_scratch_reg;
priv->throd_val = config->throd_val;
priv->scan_line_max = config->scan_line_max;
priv->scu = syscon_regmap_lookup_by_phandle(np, "syscon");
if (IS_ERR(priv->scu)) {
priv->scu = syscon_regmap_lookup_by_compatible("aspeed,ast2500-scu");
if (IS_ERR(priv->scu)) {
dev_err(&pdev->dev, "failed to find SCU regmap\n");
return PTR_ERR(priv->scu);
}
}
ret = of_reserved_mem_device_init(drm->dev);
if (ret) {
dev_err(&pdev->dev,
"failed to initialize reserved mem: %d\n", ret);
return ret;
}
ret = dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(32));
if (ret) {
dev_err(&pdev->dev, "failed to set DMA mask: %d\n", ret);
return ret;
}
priv->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
if (IS_ERR(priv->rst)) {
dev_err(&pdev->dev,
"missing or invalid reset controller device tree entry");
return PTR_ERR(priv->rst);
}
reset_control_deassert(priv->rst);
priv->clk = devm_clk_get(drm->dev, NULL);
if (IS_ERR(priv->clk)) {
dev_err(&pdev->dev,
"missing or invalid clk device tree entry");
return PTR_ERR(priv->clk);
}
clk_prepare_enable(priv->clk);
/* Sanitize control registers */
writel(0, priv->base + CRT_CTRL1);
writel(0, priv->base + CRT_CTRL2);
ret = aspeed_gfx_setup_mode_config(drm);
if (ret < 0)
return ret;
ret = drm_vblank_init(drm, 1);
if (ret < 0) {
dev_err(drm->dev, "Failed to initialise vblank\n");
return ret;
}
ret = aspeed_gfx_create_output(drm);
if (ret < 0) {
dev_err(drm->dev, "Failed to create outputs\n");
return ret;
}
ret = aspeed_gfx_create_pipe(drm);
if (ret < 0) {
dev_err(drm->dev, "Cannot setup simple display pipe\n");
return ret;
}
ret = devm_request_irq(drm->dev, platform_get_irq(pdev, 0),
aspeed_gfx_irq_handler, 0, "aspeed gfx", drm);
if (ret < 0) {
dev_err(drm->dev, "Failed to install IRQ handler\n");
return ret;
}
drm_mode_config_reset(drm);
return 0;
}
static void aspeed_gfx_unload(struct drm_device *drm)
{
drm_kms_helper_poll_fini(drm);
}
DEFINE_DRM_GEM_DMA_FOPS(fops);
static const struct drm_driver aspeed_gfx_driver = {
.driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
DRM_GEM_DMA_DRIVER_OPS,
.fops = &fops,
.name = "aspeed-gfx-drm",
.desc = "ASPEED GFX DRM",
.date = "20180319",
.major = 1,
.minor = 0,
};
static ssize_t dac_mux_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct aspeed_gfx *priv = dev_get_drvdata(dev);
u32 val;
int rc;
rc = kstrtou32(buf, 0, &val);
if (rc)
return rc;
if (val > 3)
return -EINVAL;
rc = regmap_update_bits(priv->scu, priv->dac_reg, 0x30000, val << 16);
if (rc < 0)
return 0;
return count;
}
static ssize_t dac_mux_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct aspeed_gfx *priv = dev_get_drvdata(dev);
u32 reg;
int rc;
rc = regmap_read(priv->scu, priv->dac_reg, ®);
if (rc)
return rc;
return sprintf(buf, "%u\n", (reg >> 16) & 0x3);
}
static DEVICE_ATTR_RW(dac_mux);
static ssize_t
vga_pw_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct aspeed_gfx *priv = dev_get_drvdata(dev);
u32 reg;
int rc;
rc = regmap_read(priv->scu, priv->vga_scratch_reg, ®);
if (rc)
return rc;
return sprintf(buf, "%u\n", reg);
}
static DEVICE_ATTR_RO(vga_pw);
static struct attribute *aspeed_sysfs_entries[] = {
&dev_attr_vga_pw.attr,
&dev_attr_dac_mux.attr,
NULL,
};
static struct attribute_group aspeed_sysfs_attr_group = {
.attrs = aspeed_sysfs_entries,
};
static int aspeed_gfx_probe(struct platform_device *pdev)
{
struct aspeed_gfx *priv;
int ret;
priv = devm_drm_dev_alloc(&pdev->dev, &aspeed_gfx_driver,
struct aspeed_gfx, drm);
if (IS_ERR(priv))
return PTR_ERR(priv);
ret = aspeed_gfx_load(&priv->drm);
if (ret)
return ret;
platform_set_drvdata(pdev, priv);
ret = sysfs_create_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group);
if (ret)
return ret;
ret = drm_dev_register(&priv->drm, 0);
if (ret)
goto err_unload;
drm_fbdev_dma_setup(&priv->drm, 32);
return 0;
err_unload:
sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group);
aspeed_gfx_unload(&priv->drm);
return ret;
}
static void aspeed_gfx_remove(struct platform_device *pdev)
{
struct drm_device *drm = platform_get_drvdata(pdev);
sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group);
drm_dev_unregister(drm);
aspeed_gfx_unload(drm);
drm_atomic_helper_shutdown(drm);
}
static void aspeed_gfx_shutdown(struct platform_device *pdev)
{
drm_atomic_helper_shutdown(platform_get_drvdata(pdev));
}
static struct platform_driver aspeed_gfx_platform_driver = {
.probe = aspeed_gfx_probe,
.remove_new = aspeed_gfx_remove,
.shutdown = aspeed_gfx_shutdown,
.driver = {
.name = "aspeed_gfx",
.of_match_table = aspeed_gfx_match,
},
};
drm_module_platform_driver(aspeed_gfx_platform_driver);
MODULE_AUTHOR("Joel Stanley <[email protected]>");
MODULE_DESCRIPTION("ASPEED BMC DRM/KMS driver");
MODULE_LICENSE("GPL");
Codebase Browser
linux