Commit 696029eb authored by Joel Stanley's avatar Joel Stanley
Browse files

drm/aspeed: Add sysfs for output settings 



These settings are used by an ASPEED BMC to determine when the host is
trying to drive the display over PCIe (vga_pw) and to switch the
output between PCIe and the internal graphics device (dac_mux).

The valid values for the dac mux are:

 00: VGA mode (default, aka PCIe)
 01: Graphics CRT (aka BMC internal graphics, this driver)
 10: Pass through mode from video input port A
 11: Pass through mode from video input port B

Values for the read-only vga password register are:

 1: Host driving the display
 0: Host not driving the display

Signed-off-by: default avatarJoel Stanley <joel@jms.id.au>
Reviewed-by: default avatarAndrew Jeffery <andrew@aj.id.au>
Link: https://patchwork.freedesktop.org/patch/msgid/20200916083413.777307-1-joel@jms.id.au
parent 82e1b93a

drivers/gpu/drm/aspeed/aspeed_gfx_drv.c

+71 −0
Original line number Diff line number Diff line
@@ -212,6 +212,69 @@ static const struct of_device_id aspeed_gfx_match[] = { 
	{ }

};



#define ASPEED_SCU_VGA0		0x50

#define ASPEED_SCU_MISC_CTRL	0x2c



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, ASPEED_SCU_MISC_CTRL, 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, ASPEED_SCU_MISC_CTRL, &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, ASPEED_SCU_VGA0, &reg);

	if (rc)

		return rc;



	return sprintf(buf, "%u\n", reg & 1);

}

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;
@@ -226,6 +289,12 @@ static int aspeed_gfx_probe(struct platform_device *pdev) 
	if (ret)

		return ret;



	dev_set_drvdata(&pdev->dev, 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;
@@ -234,6 +303,7 @@ static int aspeed_gfx_probe(struct platform_device *pdev) 
	return 0;



err_unload:

	sysfs_remove_group(&pdev->dev.kobj, &aspeed_sysfs_attr_group);

	aspeed_gfx_unload(&priv->drm);



	return ret;
@@ -243,6 +313,7 @@ static int 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);