DRM: i915: add mode setting support

This commit adds i915 driver support for the DRM mode setting APIs.
Currently, VGA, LVDS, SDVO DVI & VGA, TV and DVO LVDS outputs are
supported.  HDMI, DisplayPort and additional SDVO output support will
follow.

Support for the mode setting code is controlled by the new 'modeset'
module option.  A new config option, CONFIG_DRM_I915_KMS controls the
default behavior, and whether a PCI ID list is built into the module for
use by user level module utilities.

Note that if mode setting is enabled, user level drivers that access
display registers directly or that don't use the kernel graphics memory
manager will likely corrupt kernel graphics memory, disrupt output
configuration (possibly leading to hangs and/or blank displays), and
prevent panic/oops messages from appearing.  So use caution when
enabling this code; be sure your user level code supports the new
interfaces.

A new SysRq key, 'g', provides emergency support for switching back to
the kernel's framebuffer console; which is useful for testing.

Co-authors: Dave Airlie <airlied@linux.ie>, Hong Liu <hong.liu@intel.com>

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 442 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/dvo_ivch.c b/drivers/gpu/drm/i915/dvo_ivch.c
new file mode 100644
index 00000000000..0c8d375e8e3
--- /dev/null
+++ b/drivers/gpu/drm/i915/dvo_ivch.c
@@ -0,0 +1,442 @@
+/*
+ * Copyright © 2006 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Authors:
+ *    Eric Anholt <eric@anholt.net>
+ *
+ */
+
+#include "dvo.h"
+
+/*
+ * register definitions for the i82807aa.
+ *
+ * Documentation on this chipset can be found in datasheet #29069001 at
+ * intel.com.
+ */
+
+/*
+ * VCH Revision & GMBus Base Addr
+ */
+#define VR00		0x00
+# define VR00_BASE_ADDRESS_MASK		0x007f
+
+/*
+ * Functionality Enable
+ */
+#define VR01		0x01
+
+/*
+ * Enable the panel fitter
+ */
+# define VR01_PANEL_FIT_ENABLE		(1 << 3)
+/*
+ * Enables the LCD display.
+ *
+ * This must not be set while VR01_DVO_BYPASS_ENABLE is set.
+ */
+# define VR01_LCD_ENABLE		(1 << 2)
+/** Enables the DVO repeater. */
+# define VR01_DVO_BYPASS_ENABLE		(1 << 1)
+/** Enables the DVO clock */
+# define VR01_DVO_ENABLE		(1 << 0)
+
+/*
+ * LCD Interface Format
+ */
+#define VR10		0x10
+/** Enables LVDS output instead of CMOS */
+# define VR10_LVDS_ENABLE		(1 << 4)
+/** Enables 18-bit LVDS output. */
+# define VR10_INTERFACE_1X18		(0 << 2)
+/** Enables 24-bit LVDS or CMOS output */
+# define VR10_INTERFACE_1X24		(1 << 2)
+/** Enables 2x18-bit LVDS or CMOS output. */
+# define VR10_INTERFACE_2X18		(2 << 2)
+/** Enables 2x24-bit LVDS output */
+# define VR10_INTERFACE_2X24		(3 << 2)
+
+/*
+ * VR20 LCD Horizontal Display Size
+ */
+#define VR20	0x20
+
+/*
+ * LCD Vertical Display Size
+ */
+#define VR21	0x20
+
+/*
+ * Panel power down status
+ */
+#define VR30		0x30
+/** Read only bit indicating that the panel is not in a safe poweroff state. */
+# define VR30_PANEL_ON			(1 << 15)
+
+#define VR40		0x40
+# define VR40_STALL_ENABLE		(1 << 13)
+# define VR40_VERTICAL_INTERP_ENABLE	(1 << 12)
+# define VR40_ENHANCED_PANEL_FITTING	(1 << 11)
+# define VR40_HORIZONTAL_INTERP_ENABLE	(1 << 10)
+# define VR40_AUTO_RATIO_ENABLE		(1 << 9)
+# define VR40_CLOCK_GATING_ENABLE	(1 << 8)
+
+/*
+ * Panel Fitting Vertical Ratio
+ * (((image_height - 1) << 16) / ((panel_height - 1))) >> 2
+ */
+#define VR41		0x41
+
+/*
+ * Panel Fitting Horizontal Ratio
+ * (((image_width - 1) << 16) / ((panel_width - 1))) >> 2
+ */
+#define VR42		0x42
+
+/*
+ * Horizontal Image Size
+ */
+#define VR43		0x43
+
+/* VR80 GPIO 0
+ */
+#define VR80	    0x80
+#define VR81	    0x81
+#define VR82	    0x82
+#define VR83	    0x83
+#define VR84	    0x84
+#define VR85	    0x85
+#define VR86	    0x86
+#define VR87	    0x87
+
+/* VR88 GPIO 8
+ */
+#define VR88	    0x88
+
+/* Graphics BIOS scratch 0
+ */
+#define VR8E	    0x8E
+# define VR8E_PANEL_TYPE_MASK		(0xf << 0)
+# define VR8E_PANEL_INTERFACE_CMOS	(0 << 4)
+# define VR8E_PANEL_INTERFACE_LVDS	(1 << 4)
+# define VR8E_FORCE_DEFAULT_PANEL	(1 << 5)
+
+/* Graphics BIOS scratch 1
+ */
+#define VR8F	    0x8F
+# define VR8F_VCH_PRESENT		(1 << 0)
+# define VR8F_DISPLAY_CONN		(1 << 1)
+# define VR8F_POWER_MASK		(0x3c)
+# define VR8F_POWER_POS			(2)
+
+
+struct ivch_priv {
+	bool quiet;
+
+	uint16_t width, height;
+
+	uint16_t save_VR01;
+	uint16_t save_VR40;
+};
+
+
+static void ivch_dump_regs(struct intel_dvo_device *dvo);
+
+/**
+ * Reads a register on the ivch.
+ *
+ * Each of the 256 registers are 16 bits long.
+ */
+static bool ivch_read(struct intel_dvo_device *dvo, int addr, uint16_t *data)
+{
+	struct ivch_priv *priv = dvo->dev_priv;
+	struct intel_i2c_chan *i2cbus = dvo->i2c_bus;
+	u8 out_buf[1];
+	u8 in_buf[2];
+
+	struct i2c_msg msgs[] = {
+		{
+			.addr = i2cbus->slave_addr,
+			.flags = I2C_M_RD,
+			.len = 0,
+		},
+		{
+			.addr = 0,
+			.flags = I2C_M_NOSTART,
+			.len = 1,
+			.buf = out_buf,
+		},
+		{
+			.addr = i2cbus->slave_addr,
+			.flags = I2C_M_RD | I2C_M_NOSTART,
+			.len = 2,
+			.buf = in_buf,
+		}
+	};
+
+	out_buf[0] = addr;
+
+	if (i2c_transfer(&i2cbus->adapter, msgs, 3) == 3) {
+		*data = (in_buf[1] << 8) | in_buf[0];
+		return true;
+	};
+
+	if (!priv->quiet) {
+		DRM_DEBUG("Unable to read register 0x%02x from %s:%02x.\n",
+			  addr, i2cbus->adapter.name, i2cbus->slave_addr);
+	}
+	return false;
+}
+
+/** Writes a 16-bit register on the ivch */
+static bool ivch_write(struct intel_dvo_device *dvo, int addr, uint16_t data)
+{
+	struct ivch_priv *priv = dvo->dev_priv;
+	struct intel_i2c_chan *i2cbus = dvo->i2c_bus;
+	u8 out_buf[3];
+	struct i2c_msg msg = {
+		.addr = i2cbus->slave_addr,
+		.flags = 0,
+		.len = 3,
+		.buf = out_buf,
+	};
+
+	out_buf[0] = addr;
+	out_buf[1] = data & 0xff;
+	out_buf[2] = data >> 8;
+
+	if (i2c_transfer(&i2cbus->adapter, &msg, 1) == 1)
+		return true;
+
+	if (!priv->quiet) {
+		DRM_DEBUG("Unable to write register 0x%02x to %s:%d.\n",
+			  addr, i2cbus->adapter.name, i2cbus->slave_addr);
+	}
+
+	return false;
+}
+
+/** Probes the given bus and slave address for an ivch */
+static bool ivch_init(struct intel_dvo_device *dvo,
+		      struct intel_i2c_chan *i2cbus)
+{
+	struct ivch_priv *priv;
+	uint16_t temp;
+
+	priv = kzalloc(sizeof(struct ivch_priv), GFP_KERNEL);
+	if (priv == NULL)
+		return false;
+
+	dvo->i2c_bus = i2cbus;
+	dvo->i2c_bus->slave_addr = dvo->slave_addr;
+	dvo->dev_priv = priv;
+	priv->quiet = true;
+
+	if (!ivch_read(dvo, VR00, &temp))
+		goto out;
+	priv->quiet = false;
+
+	/* Since the identification bits are probably zeroes, which doesn't seem
+	 * very unique, check that the value in the base address field matches
+	 * the address it's responding on.
+	 */
+	if ((temp & VR00_BASE_ADDRESS_MASK) != dvo->slave_addr) {
+		DRM_DEBUG("ivch detect failed due to address mismatch "
+			  "(%d vs %d)\n",
+			  (temp & VR00_BASE_ADDRESS_MASK), dvo->slave_addr);
+		goto out;
+	}
+
+	ivch_read(dvo, VR20, &priv->width);
+	ivch_read(dvo, VR21, &priv->height);
+
+	return true;
+
+out:
+	kfree(priv);
+	return false;
+}
+
+static enum drm_connector_status ivch_detect(struct intel_dvo_device *dvo)
+{
+	return connector_status_connected;
+}
+
+static enum drm_mode_status ivch_mode_valid(struct intel_dvo_device *dvo,
+					    struct drm_display_mode *mode)
+{
+	if (mode->clock > 112000)
+		return MODE_CLOCK_HIGH;
+
+	return MODE_OK;
+}
+
+/** Sets the power state of the panel connected to the ivch */
+static void ivch_dpms(struct intel_dvo_device *dvo, int mode)
+{
+	int i;
+	uint16_t vr01, vr30, backlight;
+
+	/* Set the new power state of the panel. */
+	if (!ivch_read(dvo, VR01, &vr01))
+		return;
+
+	if (mode == DRM_MODE_DPMS_ON)
+		backlight = 1;
+	else
+		backlight = 0;
+	ivch_write(dvo, VR80, backlight);
+
+	if (mode == DRM_MODE_DPMS_ON)
+		vr01 |= VR01_LCD_ENABLE | VR01_DVO_ENABLE;
+	else
+		vr01 &= ~(VR01_LCD_ENABLE | VR01_DVO_ENABLE);
+
+	ivch_write(dvo, VR01, vr01);
+
+	/* Wait for the panel to make its state transition */
+	for (i = 0; i < 100; i++) {
+		if (!ivch_read(dvo, VR30, &vr30))
+			break;
+
+		if (((vr30 & VR30_PANEL_ON) != 0) == (mode == DRM_MODE_DPMS_ON))
+			break;
+		udelay(1000);
+	}
+	/* wait some more; vch may fail to resync sometimes without this */
+	udelay(16 * 1000);
+}
+
+static void ivch_mode_set(struct intel_dvo_device *dvo,
+			  struct drm_display_mode *mode,
+			  struct drm_display_mode *adjusted_mode)
+{
+	uint16_t vr40 = 0;
+	uint16_t vr01;
+
+	vr01 = 0;
+	vr40 = (VR40_STALL_ENABLE | VR40_VERTICAL_INTERP_ENABLE |
+		VR40_HORIZONTAL_INTERP_ENABLE);
+
+	if (mode->hdisplay != adjusted_mode->hdisplay ||
+	    mode->vdisplay != adjusted_mode->vdisplay) {
+		uint16_t x_ratio, y_ratio;
+
+		vr01 |= VR01_PANEL_FIT_ENABLE;
+		vr40 |= VR40_CLOCK_GATING_ENABLE;
+		x_ratio = (((mode->hdisplay - 1) << 16) /
+			   (adjusted_mode->hdisplay - 1)) >> 2;
+		y_ratio = (((mode->vdisplay - 1) << 16) /
+			   (adjusted_mode->vdisplay - 1)) >> 2;
+		ivch_write (dvo, VR42, x_ratio);
+		ivch_write (dvo, VR41, y_ratio);
+	} else {
+		vr01 &= ~VR01_PANEL_FIT_ENABLE;
+		vr40 &= ~VR40_CLOCK_GATING_ENABLE;
+	}
+	vr40 &= ~VR40_AUTO_RATIO_ENABLE;
+
+	ivch_write(dvo, VR01, vr01);
+	ivch_write(dvo, VR40, vr40);
+
+	ivch_dump_regs(dvo);
+}
+
+static void ivch_dump_regs(struct intel_dvo_device *dvo)
+{
+	uint16_t val;
+
+	ivch_read(dvo, VR00, &val);
+	DRM_DEBUG("VR00: 0x%04x\n", val);
+	ivch_read(dvo, VR01, &val);
+	DRM_DEBUG("VR01: 0x%04x\n", val);
+	ivch_read(dvo, VR30, &val);
+	DRM_DEBUG("VR30: 0x%04x\n", val);
+	ivch_read(dvo, VR40, &val);
+	DRM_DEBUG("VR40: 0x%04x\n", val);
+
+	/* GPIO registers */
+	ivch_read(dvo, VR80, &val);
+	DRM_DEBUG("VR80: 0x%04x\n", val);
+	ivch_read(dvo, VR81, &val);
+	DRM_DEBUG("VR81: 0x%04x\n", val);
+	ivch_read(dvo, VR82, &val);
+	DRM_DEBUG("VR82: 0x%04x\n", val);
+	ivch_read(dvo, VR83, &val);
+	DRM_DEBUG("VR83: 0x%04x\n", val);
+	ivch_read(dvo, VR84, &val);
+	DRM_DEBUG("VR84: 0x%04x\n", val);
+	ivch_read(dvo, VR85, &val);
+	DRM_DEBUG("VR85: 0x%04x\n", val);
+	ivch_read(dvo, VR86, &val);
+	DRM_DEBUG("VR86: 0x%04x\n", val);
+	ivch_read(dvo, VR87, &val);
+	DRM_DEBUG("VR87: 0x%04x\n", val);
+	ivch_read(dvo, VR88, &val);
+	DRM_DEBUG("VR88: 0x%04x\n", val);
+
+	/* Scratch register 0 - AIM Panel type */
+	ivch_read(dvo, VR8E, &val);
+	DRM_DEBUG("VR8E: 0x%04x\n", val);
+
+	/* Scratch register 1 - Status register */
+	ivch_read(dvo, VR8F, &val);
+	DRM_DEBUG("VR8F: 0x%04x\n", val);
+}
+
+static void ivch_save(struct intel_dvo_device *dvo)
+{
+	struct ivch_priv *priv = dvo->dev_priv;
+
+	ivch_read(dvo, VR01, &priv->save_VR01);
+	ivch_read(dvo, VR40, &priv->save_VR40);
+}
+
+static void ivch_restore(struct intel_dvo_device *dvo)
+{
+	struct ivch_priv *priv = dvo->dev_priv;
+
+	ivch_write(dvo, VR01, priv->save_VR01);
+	ivch_write(dvo, VR40, priv->save_VR40);
+}
+
+static void ivch_destroy(struct intel_dvo_device *dvo)
+{
+	struct ivch_priv *priv = dvo->dev_priv;
+
+	if (priv) {
+		kfree(priv);
+		dvo->dev_priv = NULL;
+	}
+}
+
+struct intel_dvo_dev_ops ivch_ops= {
+	.init = ivch_init,
+	.dpms = ivch_dpms,
+	.save = ivch_save,
+	.restore = ivch_restore,
+	.mode_valid = ivch_mode_valid,
+	.mode_set = ivch_mode_set,
+	.detect = ivch_detect,
+	.dump_regs = ivch_dump_regs,
+	.destroy = ivch_destroy,
+};