drm/radeon/kms: add support for hw i2c on r1xx-r5xx

wire hw i2c support into radeon i2c algo.

fixes merged:
- handle bus probing correctly
- use meaningful error numbers
- abort if transaction fails
- The line mapping is different depending on the asic.
- protect hw i2c engine with a mutex
- rs300 doesn't have a pin select bit
- r200 has a different pin select setup

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

6 files changed, 736 insertions, 82 deletions

diff --git a/drivers/gpu/drm/radeon/r500_reg.h b/drivers/gpu/drm/radeon/r500_reg.h
index 74ad89bdf2b..0cf2ad2a558 100644
--- a/drivers/gpu/drm/radeon/r500_reg.h
+++ b/drivers/gpu/drm/radeon/r500_reg.h
@@ -717,54 +717,62 @@
 #define AVIVO_DVOA_BIT_DEPTH_CONTROL			0x7988
 
 #define AVIVO_DC_GPIO_HPD_A                 0x7e94
-
-#define AVIVO_GPIO_0                        0x7e30
-#define AVIVO_GPIO_1                        0x7e40
-#define AVIVO_GPIO_2                        0x7e50
-#define AVIVO_GPIO_3                        0x7e60
-
 #define AVIVO_DC_GPIO_HPD_Y                 0x7e9c
 
-#define AVIVO_I2C_STATUS					0x7d30
-#	define AVIVO_I2C_STATUS_DONE				(1 << 0)
-#	define AVIVO_I2C_STATUS_NACK				(1 << 1)
-#	define AVIVO_I2C_STATUS_HALT				(1 << 2)
-#	define AVIVO_I2C_STATUS_GO				(1 << 3)
-#	define AVIVO_I2C_STATUS_MASK				0x7
-/* If radeon_mm_i2c is to be believed, this is HALT, NACK, and maybe
- * DONE? */
-#	define AVIVO_I2C_STATUS_CMD_RESET			0x7
-#	define AVIVO_I2C_STATUS_CMD_WAIT			(1 << 3)
-#define AVIVO_I2C_STOP						0x7d34
-#define AVIVO_I2C_START_CNTL				0x7d38
-#	define AVIVO_I2C_START						(1 << 8)
-#	define AVIVO_I2C_CONNECTOR0					(0 << 16)
-#	define AVIVO_I2C_CONNECTOR1					(1 << 16)
-#define R520_I2C_START (1<<0)
-#define R520_I2C_STOP (1<<1)
-#define R520_I2C_RX (1<<2)
-#define R520_I2C_EN (1<<8)
-#define R520_I2C_DDC1 (0<<16)
-#define R520_I2C_DDC2 (1<<16)
-#define R520_I2C_DDC3 (2<<16)
-#define R520_I2C_DDC_MASK (3<<16)
-#define AVIVO_I2C_CONTROL2					0x7d3c
-#	define AVIVO_I2C_7D3C_SIZE_SHIFT			8
-#	define AVIVO_I2C_7D3C_SIZE_MASK				(0xf << 8)
-#define AVIVO_I2C_CONTROL3						0x7d40
-/* Reading is done 4 bytes at a time: read the bottom 8 bits from
- * 7d44, four times in a row.
- * Writing is a little more complex.  First write DATA with
- * 0xnnnnnnzz, then 0xnnnnnnyy, where nnnnnn is some non-deterministic
- * magic number, zz is, I think, the slave address, and yy is the byte
- * you want to write. */
-#define AVIVO_I2C_DATA						0x7d44
-#define R520_I2C_ADDR_COUNT_MASK (0x7)
-#define R520_I2C_DATA_COUNT_SHIFT (8)
-#define R520_I2C_DATA_COUNT_MASK (0xF00)
-#define AVIVO_I2C_CNTL						0x7d50
-#	define AVIVO_I2C_EN							(1 << 0)
-#	define AVIVO_I2C_RESET						(1 << 8)
+#define AVIVO_DC_I2C_STATUS1				0x7d30
+#	define AVIVO_DC_I2C_DONE			(1 << 0)
+#	define AVIVO_DC_I2C_NACK			(1 << 1)
+#	define AVIVO_DC_I2C_HALT			(1 << 2)
+#	define AVIVO_DC_I2C_GO			        (1 << 3)
+#define AVIVO_DC_I2C_RESET 				0x7d34
+#	define AVIVO_DC_I2C_SOFT_RESET			(1 << 0)
+#	define AVIVO_DC_I2C_ABORT			(1 << 8)
+#define AVIVO_DC_I2C_CONTROL1 				0x7d38
+#	define AVIVO_DC_I2C_START			(1 << 0)
+#	define AVIVO_DC_I2C_STOP			(1 << 1)
+#	define AVIVO_DC_I2C_RECEIVE			(1 << 2)
+#	define AVIVO_DC_I2C_EN			        (1 << 8)
+#	define AVIVO_DC_I2C_PIN_SELECT(x)		((x) << 16)
+#	define AVIVO_SEL_DDC1			        0
+#	define AVIVO_SEL_DDC2			        1
+#	define AVIVO_SEL_DDC3			        2
+#define AVIVO_DC_I2C_CONTROL2 				0x7d3c
+#	define AVIVO_DC_I2C_ADDR_COUNT(x)		((x) << 0)
+#	define AVIVO_DC_I2C_DATA_COUNT(x)		((x) << 8)
+#define AVIVO_DC_I2C_CONTROL3 				0x7d40
+#	define AVIVO_DC_I2C_DATA_DRIVE_EN		(1 << 0)
+#	define AVIVO_DC_I2C_DATA_DRIVE_SEL		(1 << 1)
+#	define AVIVO_DC_I2C_CLK_DRIVE_EN		(1 << 7)
+#	define AVIVO_DC_I2C_RD_INTRA_BYTE_DELAY(x)      ((x) << 8)
+#	define AVIVO_DC_I2C_WR_INTRA_BYTE_DELAY(x)	((x) << 16)
+#	define AVIVO_DC_I2C_TIME_LIMIT(x)		((x) << 24)
+#define AVIVO_DC_I2C_DATA 				0x7d44
+#define AVIVO_DC_I2C_INTERRUPT_CONTROL 			0x7d48
+#	define AVIVO_DC_I2C_INTERRUPT_STATUS		(1 << 0)
+#	define AVIVO_DC_I2C_INTERRUPT_AK		(1 << 8)
+#	define AVIVO_DC_I2C_INTERRUPT_ENABLE		(1 << 16)
+#define AVIVO_DC_I2C_ARBITRATION 			0x7d50
+#	define AVIVO_DC_I2C_SW_WANTS_TO_USE_I2C		(1 << 0)
+#	define AVIVO_DC_I2C_SW_CAN_USE_I2C		(1 << 1)
+#	define AVIVO_DC_I2C_SW_DONE_USING_I2C		(1 << 8)
+#	define AVIVO_DC_I2C_HW_NEEDS_I2C		(1 << 9)
+#	define AVIVO_DC_I2C_ABORT_HDCP_I2C		(1 << 16)
+#	define AVIVO_DC_I2C_HW_USING_I2C		(1 << 17)
+
+#define AVIVO_DC_GPIO_DDC1_MASK 		        0x7e40
+#define AVIVO_DC_GPIO_DDC1_A 		                0x7e44
+#define AVIVO_DC_GPIO_DDC1_EN 		                0x7e48
+#define AVIVO_DC_GPIO_DDC1_Y 		                0x7e4c
+
+#define AVIVO_DC_GPIO_DDC2_MASK 		        0x7e50
+#define AVIVO_DC_GPIO_DDC2_A 		                0x7e54
+#define AVIVO_DC_GPIO_DDC2_EN 		                0x7e58
+#define AVIVO_DC_GPIO_DDC2_Y 		                0x7e5c
+
+#define AVIVO_DC_GPIO_DDC3_MASK 		        0x7e60
+#define AVIVO_DC_GPIO_DDC3_A 		                0x7e64
+#define AVIVO_DC_GPIO_DDC3_EN 		                0x7e68
+#define AVIVO_DC_GPIO_DDC3_Y 		                0x7e6c
 
 #define AVIVO_DISP_INTERRUPT_STATUS                             0x7edc
 #       define AVIVO_D1_VBLANK_INTERRUPT                        (1 << 4)
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index f57480ba135..88113f756ab 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -829,6 +829,7 @@ struct radeon_device {
 	struct r600_ih ih; /* r6/700 interrupt ring */
 	struct workqueue_struct *wq;
 	struct work_struct hotplug_work;
+	struct mutex dc_hw_i2c_mutex; /* display controller hw i2c mutex */
 
 	/* audio stuff */
 	struct timer_list	audio_timer;
diff --git a/drivers/gpu/drm/radeon/radeon_combios.c b/drivers/gpu/drm/radeon/radeon_combios.c
index 318afe83e6b..e208d730f51 100644
--- a/drivers/gpu/drm/radeon/radeon_combios.c
+++ b/drivers/gpu/drm/radeon/radeon_combios.c
@@ -486,9 +486,65 @@ static struct radeon_i2c_bus_rec combios_setup_i2c_bus(struct radeon_device *rde
 		i2c.y_data_reg = ddc_line;
 	}
 
-	if (rdev->family < CHIP_R200)
-		i2c.hw_capable = false;
-	else {
+	switch (rdev->family) {
+	case CHIP_R100:
+	case CHIP_RV100:
+	case CHIP_RS100:
+	case CHIP_RV200:
+	case CHIP_RS200:
+	case CHIP_RS300:
+		switch (ddc_line) {
+		case RADEON_GPIO_DVI_DDC:
+			/* in theory this should be hw capable,
+			 * but it doesn't seem to work
+			 */
+			i2c.hw_capable = false;
+			break;
+		default:
+			i2c.hw_capable = false;
+			break;
+		}
+		break;
+	case CHIP_R200:
+		switch (ddc_line) {
+		case RADEON_GPIO_DVI_DDC:
+		case RADEON_GPIO_MONID:
+			i2c.hw_capable = true;
+			break;
+		default:
+			i2c.hw_capable = false;
+			break;
+		}
+		break;
+	case CHIP_RV250:
+	case CHIP_RV280:
+		switch (ddc_line) {
+		case RADEON_GPIO_VGA_DDC:
+		case RADEON_GPIO_DVI_DDC:
+		case RADEON_GPIO_CRT2_DDC:
+			i2c.hw_capable = true;
+			break;
+		default:
+			i2c.hw_capable = false;
+			break;
+		}
+		break;
+	case CHIP_R300:
+	case CHIP_R350:
+		switch (ddc_line) {
+		case RADEON_GPIO_VGA_DDC:
+		case RADEON_GPIO_DVI_DDC:
+			i2c.hw_capable = true;
+			break;
+		default:
+			i2c.hw_capable = false;
+			break;
+		}
+		break;
+	case CHIP_RV350:
+	case CHIP_RV380:
+	case CHIP_RS400:
+	case CHIP_RS480:
 		switch (ddc_line) {
 		case RADEON_GPIO_VGA_DDC:
 		case RADEON_GPIO_DVI_DDC:
@@ -504,6 +560,10 @@ static struct radeon_i2c_bus_rec combios_setup_i2c_bus(struct radeon_device *rde
 			i2c.hw_capable = false;
 			break;
 		}
+		break;
+	default:
+		i2c.hw_capable = false;
+		break;
 	}
 	i2c.mm_i2c = false;
 	i2c.i2c_id = 0;
@@ -1253,7 +1313,10 @@ bool radeon_legacy_get_ext_tmds_info_from_combios(struct radeon_encoder *encoder
 				tmds->i2c_bus = radeon_i2c_create(dev, &i2c_bus, "DVO");
 				break;
 			case DDC_LCD: /* MM i2c */
-				DRM_ERROR("MM i2c requires hw i2c engine\n");
+				i2c_bus.valid = true;
+				i2c_bus.hw_capable = true;
+				i2c_bus.mm_i2c = true;
+				tmds->i2c_bus = radeon_i2c_create(dev, &i2c_bus, "DVO");
 				break;
 			default:
 				DRM_ERROR("Unsupported gpio %d\n", gpio);
diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
index 768b1509fa0..18ac29c505c 100644
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -638,6 +638,7 @@ int radeon_device_init(struct radeon_device *rdev,
 	mutex_init(&rdev->cs_mutex);
 	mutex_init(&rdev->ib_pool.mutex);
 	mutex_init(&rdev->cp.mutex);
+	mutex_init(&rdev->dc_hw_i2c_mutex);
 	if (rdev->family >= CHIP_R600)
 		spin_lock_init(&rdev->ih.lock);
 	mutex_init(&rdev->gem.mutex);
diff --git a/drivers/gpu/drm/radeon/radeon_i2c.c b/drivers/gpu/drm/radeon/radeon_i2c.c
index 75b090f6020..b47a5615fe6 100644
--- a/drivers/gpu/drm/radeon/radeon_i2c.c
+++ b/drivers/gpu/drm/radeon/radeon_i2c.c
@@ -26,6 +26,7 @@
 #include "drmP.h"
 #include "radeon_drm.h"
 #include "radeon.h"
+#include "atom.h"
 
 /**
  * radeon_ddc_probe
@@ -71,13 +72,25 @@ static void radeon_i2c_do_lock(struct radeon_i2c_chan *i2c, int lock_state)
 	 */
 	if (rec->hw_capable) {
 		if ((rdev->family >= CHIP_R200) && !ASIC_IS_AVIVO(rdev)) {
-			if (rec->a_clk_reg == RADEON_GPIO_MONID) {
+			u32 reg;
+
+			if (rdev->family >= CHIP_RV350)
+				reg = RADEON_GPIO_MONID;
+			else if ((rdev->family == CHIP_R300) ||
+				 (rdev->family == CHIP_R350))
+				reg = RADEON_GPIO_DVI_DDC;
+			else
+				reg = RADEON_GPIO_CRT2_DDC;
+
+			mutex_lock(&rdev->dc_hw_i2c_mutex);
+			if (rec->a_clk_reg == reg) {
 				WREG32(RADEON_DVI_I2C_CNTL_0, (RADEON_I2C_SOFT_RST |
 							       R200_DVI_I2C_PIN_SEL(R200_SEL_DDC1)));
 			} else {
 				WREG32(RADEON_DVI_I2C_CNTL_0, (RADEON_I2C_SOFT_RST |
 							       R200_DVI_I2C_PIN_SEL(R200_SEL_DDC3)));
 			}
+			mutex_unlock(&rdev->dc_hw_i2c_mutex);
 		}
 	}
 
@@ -168,22 +181,584 @@ static void set_data(void *i2c_priv, int data)
 	WREG32(rec->en_data_reg, val);
 }
 
-static int radeon_i2c_xfer(struct i2c_adapter *i2c_adap,
-			   struct i2c_msg *msgs, int num)
+/* hw i2c engine for r1xx-4xx hardware
+ * hw can buffer up to 15 bytes
+ */
+static int r100_hw_i2c_xfer(struct i2c_adapter *i2c_adap,
+			    struct i2c_msg *msgs, int num)
+{
+	struct radeon_i2c_chan *i2c = i2c_get_adapdata(i2c_adap);
+	struct radeon_device *rdev = i2c->dev->dev_private;
+	struct radeon_i2c_bus_rec *rec = &i2c->rec;
+	struct i2c_msg *p;
+	int i, j, k, ret = num;
+	/* XXX: use get_engine_clock() to get the current sclk */
+	u32 prescale = (((rdev->clock.default_sclk * 10)/(4 * 128 * 100) + 1) << 8) + 128;
+	u32 i2c_cntl_0, i2c_cntl_1, i2c_data;
+	u32 tmp, reg;
+
+	mutex_lock(&rdev->dc_hw_i2c_mutex);
+
+	reg = ((prescale << RADEON_I2C_PRESCALE_SHIFT) |
+	       RADEON_I2C_START |
+	       RADEON_I2C_STOP |
+	       RADEON_I2C_GO);
+
+	if (rdev->is_atom_bios) {
+		tmp = RREG32(RADEON_BIOS_6_SCRATCH);
+		WREG32(RADEON_BIOS_6_SCRATCH, tmp | ATOM_S6_HW_I2C_BUSY_STATE);
+	}
+
+	if (rec->mm_i2c) {
+		i2c_cntl_0 = RADEON_I2C_CNTL_0;
+		i2c_cntl_1 = RADEON_I2C_CNTL_1;
+		i2c_data = RADEON_I2C_DATA;
+	} else {
+		i2c_cntl_0 = RADEON_DVI_I2C_CNTL_0;
+		i2c_cntl_1 = RADEON_DVI_I2C_CNTL_1;
+		i2c_data = RADEON_DVI_I2C_DATA;
+
+		switch (rdev->family) {
+		case CHIP_R100:
+		case CHIP_RV100:
+		case CHIP_RS100:
+		case CHIP_RV200:
+		case CHIP_RS200:
+		case CHIP_RS300:
+			switch (rec->mask_clk_reg) {
+			case RADEON_GPIO_DVI_DDC:
+				/* no gpio select bit */
+				break;
+			default:
+				DRM_ERROR("gpio not supported with hw i2c\n");
+				ret = -EINVAL;
+				goto done;
+			}
+			break;
+		case CHIP_R200:
+			/* only bit 4 on r200 */
+			switch (rec->mask_clk_reg) {
+			case RADEON_GPIO_DVI_DDC:
+				reg |= R200_DVI_I2C_PIN_SEL(R200_SEL_DDC1);
+				break;
+			case RADEON_GPIO_MONID:
+				reg |= R200_DVI_I2C_PIN_SEL(R200_SEL_DDC3);
+				break;
+			default:
+				DRM_ERROR("gpio not supported with hw i2c\n");
+				ret = -EINVAL;
+				goto done;
+			}
+			break;
+		case CHIP_RV250:
+		case CHIP_RV280:
+			/* bits 3 and 4 */
+			switch (rec->mask_clk_reg) {
+			case RADEON_GPIO_DVI_DDC:
+				reg |= R200_DVI_I2C_PIN_SEL(R200_SEL_DDC1);
+				break;
+			case RADEON_GPIO_VGA_DDC:
+				reg |= R200_DVI_I2C_PIN_SEL(R200_SEL_DDC2);
+				break;
+			case RADEON_GPIO_CRT2_DDC:
+				reg |= R200_DVI_I2C_PIN_SEL(R200_SEL_DDC3);
+				break;
+			default:
+				DRM_ERROR("gpio not supported with hw i2c\n");
+				ret = -EINVAL;
+				goto done;
+			}
+			break;
+		case CHIP_R300:
+		case CHIP_R350:
+			/* only bit 4 on r300/r350 */
+			switch (rec->mask_clk_reg) {
+			case RADEON_GPIO_VGA_DDC:
+				reg |= R200_DVI_I2C_PIN_SEL(R200_SEL_DDC1);
+				break;
+			case RADEON_GPIO_DVI_DDC:
+				reg |= R200_DVI_I2C_PIN_SEL(R200_SEL_DDC3);
+				break;
+			default:
+				DRM_ERROR("gpio not supported with hw i2c\n");
+				ret = -EINVAL;
+				goto done;
+			}
+			break;
+		case CHIP_RV350:
+		case CHIP_RV380:
+		case CHIP_R420:
+		case CHIP_R423:
+		case CHIP_RV410:
+		case CHIP_RS400:
+		case CHIP_RS480:
+			/* bits 3 and 4 */
+			switch (rec->mask_clk_reg) {
+			case RADEON_GPIO_VGA_DDC:
+				reg |= R200_DVI_I2C_PIN_SEL(R200_SEL_DDC1);
+				break;
+			case RADEON_GPIO_DVI_DDC:
+				reg |= R200_DVI_I2C_PIN_SEL(R200_SEL_DDC2);
+				break;
+			case RADEON_GPIO_MONID:
+				reg |= R200_DVI_I2C_PIN_SEL(R200_SEL_DDC3);
+				break;
+			default:
+				DRM_ERROR("gpio not supported with hw i2c\n");
+				ret = -EINVAL;
+				goto done;
+			}
+			break;
+		default:
+			DRM_ERROR("unsupported asic\n");
+			ret = -EINVAL;
+			goto done;
+			break;
+		}
+	}
+
+	/* check for bus probe */
+	p = &msgs[0];
+	if ((num == 1) && (p->len == 0)) {
+		WREG32(i2c_cntl_0, (RADEON_I2C_DONE |
+				    RADEON_I2C_NACK |
+				    RADEON_I2C_HALT |
+				    RADEON_I2C_SOFT_RST));
+		WREG32(i2c_data, (p->addr << 1) & 0xff);
+		WREG32(i2c_data, 0);
+		WREG32(i2c_cntl_1, ((1 << RADEON_I2C_DATA_COUNT_SHIFT) |
+				    (1 << RADEON_I2C_ADDR_COUNT_SHIFT) |
+				    RADEON_I2C_EN |
+				    (48 << RADEON_I2C_TIME_LIMIT_SHIFT)));
+		WREG32(i2c_cntl_0, reg);
+		for (k = 0; k < 32; k++) {
+			udelay(10);
+			tmp = RREG32(i2c_cntl_0);
+			if (tmp & RADEON_I2C_GO)
+				continue;
+			tmp = RREG32(i2c_cntl_0);
+			if (tmp & RADEON_I2C_DONE)
+				break;
+			else {
+				DRM_DEBUG("i2c write error 0x%08x\n", tmp);
+				WREG32(i2c_cntl_0, tmp | RADEON_I2C_ABORT);
+				ret = -EIO;
+				goto done;
+			}
+		}
+		goto done;
+	}
+
+	for (i = 0; i < num; i++) {
+		p = &msgs[i];
+		for (j = 0; j < p->len; j++) {
+			if (p->flags & I2C_M_RD) {
+				WREG32(i2c_cntl_0, (RADEON_I2C_DONE |
+						    RADEON_I2C_NACK |
+						    RADEON_I2C_HALT |
+						    RADEON_I2C_SOFT_RST));
+				WREG32(i2c_data, ((p->addr << 1) & 0xff) | 0x1);
+				WREG32(i2c_cntl_1, ((1 << RADEON_I2C_DATA_COUNT_SHIFT) |
+						    (1 << RADEON_I2C_ADDR_COUNT_SHIFT) |
+						    RADEON_I2C_EN |
+						    (48 << RADEON_I2C_TIME_LIMIT_SHIFT)));
+				WREG32(i2c_cntl_0, reg | RADEON_I2C_RECEIVE);
+				for (k = 0; k < 32; k++) {
+					udelay(10);
+					tmp = RREG32(i2c_cntl_0);
+					if (tmp & RADEON_I2C_GO)
+						continue;
+					tmp = RREG32(i2c_cntl_0);
+					if (tmp & RADEON_I2C_DONE)
+						break;
+					else {
+						DRM_DEBUG("i2c read error 0x%08x\n", tmp);
+						WREG32(i2c_cntl_0, tmp | RADEON_I2C_ABORT);
+						ret = -EIO;
+						goto done;
+					}
+				}
+				p->buf[j] = RREG32(i2c_data) & 0xff;
+			} else {
+				WREG32(i2c_cntl_0, (RADEON_I2C_DONE |
+						    RADEON_I2C_NACK |
+						    RADEON_I2C_HALT |
+						    RADEON_I2C_SOFT_RST));
+				WREG32(i2c_data, (p->addr << 1) & 0xff);
+				WREG32(i2c_data, p->buf[j]);
+				WREG32(i2c_cntl_1, ((1 << RADEON_I2C_DATA_COUNT_SHIFT) |
+						    (1 << RADEON_I2C_ADDR_COUNT_SHIFT) |
+						    RADEON_I2C_EN |
+						    (48 << RADEON_I2C_TIME_LIMIT_SHIFT)));
+				WREG32(i2c_cntl_0, reg);
+				for (k = 0; k < 32; k++) {
+					udelay(10);
+					tmp = RREG32(i2c_cntl_0);
+					if (tmp & RADEON_I2C_GO)
+						continue;
+					tmp = RREG32(i2c_cntl_0);
+					if (tmp & RADEON_I2C_DONE)
+						break;
+					else {
+						DRM_DEBUG("i2c write error 0x%08x\n", tmp);
+						WREG32(i2c_cntl_0, tmp | RADEON_I2C_ABORT);
+						ret = -EIO;
+						goto done;
+					}
+				}
+			}
+		}
+	}
+
+done:
+	WREG32(i2c_cntl_0, 0);
+	WREG32(i2c_cntl_1, 0);
+	WREG32(i2c_cntl_0, (RADEON_I2C_DONE |
+			    RADEON_I2C_NACK |
+			    RADEON_I2C_HALT |
+			    RADEON_I2C_SOFT_RST));
+
+	if (rdev->is_atom_bios) {
+		tmp = RREG32(RADEON_BIOS_6_SCRATCH);
+		tmp &= ~ATOM_S6_HW_I2C_BUSY_STATE;
+		WREG32(RADEON_BIOS_6_SCRATCH, tmp);
+	}
+
+	mutex_unlock(&rdev->dc_hw_i2c_mutex);
+
+	return ret;
+}
+
+/* hw i2c engine for r5xx hardware
+ * hw can buffer up to 15 bytes
+ */
+static int r500_hw_i2c_xfer(struct i2c_adapter *i2c_adap,
+			    struct i2c_msg *msgs, int num)
+{
+	struct radeon_i2c_chan *i2c = i2c_get_adapdata(i2c_adap);
+	struct radeon_device *rdev = i2c->dev->dev_private;
+	struct radeon_i2c_bus_rec *rec = &i2c->rec;
+	struct i2c_msg *p;
+	int i2c_clock = 50;
+	int i, j, remaining, current_count, buffer_offset, ret = num;
+	/* XXX: use get_engine_clock() to get the current sclk */
+	u32 prescale;
+	u32 tmp, reg;
+	u32 saved1, saved2;
+
+	mutex_lock(&rdev->dc_hw_i2c_mutex);
+
+	/* clear gpio mask bits */
+	tmp = RREG32(rec->mask_clk_reg);
+	tmp &= ~rec->mask_clk_mask;
+	WREG32(rec->mask_clk_reg, tmp);
+	tmp = RREG32(rec->mask_clk_reg);
+
+	tmp = RREG32(rec->mask_data_reg);
+	tmp &= ~rec->mask_data_mask;
+	WREG32(rec->mask_data_reg, tmp);
+	tmp = RREG32(rec->mask_data_reg);
+
+	/* clear pin values */
+	tmp = RREG32(rec->a_clk_reg);
+	tmp &= ~rec->a_clk_mask;
+	WREG32(rec->a_clk_reg, tmp);
+	tmp = RREG32(rec->a_clk_reg);
+
+	tmp = RREG32(rec->a_data_reg);
+	tmp &= ~rec->a_data_mask;
+	WREG32(rec->a_data_reg, tmp);
+	tmp = RREG32(rec->a_data_reg);
+
+	/* set the pins to input */
+	tmp = RREG32(rec->en_clk_reg);
+	tmp &= ~rec->en_clk_mask;
+	WREG32(rec->en_clk_reg, tmp);
+	tmp = RREG32(rec->en_clk_reg);
+
+	tmp = RREG32(rec->en_data_reg);
+	tmp &= ~rec->en_data_mask;
+	WREG32(rec->en_data_reg, tmp);
+	tmp = RREG32(rec->en_data_reg);
+
+	/* */
+	tmp = RREG32(RADEON_BIOS_6_SCRATCH);
+	WREG32(RADEON_BIOS_6_SCRATCH, tmp | ATOM_S6_HW_I2C_BUSY_STATE);
+	saved1 = RREG32(AVIVO_DC_I2C_CONTROL1);
+	saved2 = RREG32(0x494);
+	WREG32(0x494, saved2 | 0x1);
+
+	WREG32(AVIVO_DC_I2C_ARBITRATION, AVIVO_DC_I2C_SW_WANTS_TO_USE_I2C);
+	for (i = 0; i < 50; i++) {
+		udelay(1);
+		if (RREG32(AVIVO_DC_I2C_ARBITRATION) & AVIVO_DC_I2C_SW_CAN_USE_I2C)
+			break;
+	}
+	if (i == 50) {
+		DRM_ERROR("failed to get i2c bus\n");
+		ret = -EBUSY;
+		goto done;
+	}
+
+	if (rdev->family == CHIP_R520)
+		prescale = (127 << 8) + ((rdev->clock.default_sclk * 10) / (4 * 127 * i2c_clock));
+	else
+		prescale = (((rdev->clock.default_sclk * 10)/(4 * 128 * 100) + 1) << 8) + 128;
+
+	reg = AVIVO_DC_I2C_START | AVIVO_DC_I2C_STOP | AVIVO_DC_I2C_EN;
+	switch (rec->mask_clk_reg) {
+	case AVIVO_DC_GPIO_DDC1_MASK:
+		reg |= AVIVO_DC_I2C_PIN_SELECT(AVIVO_SEL_DDC1);
+		break;
+	case AVIVO_DC_GPIO_DDC2_MASK:
+		reg |= AVIVO_DC_I2C_PIN_SELECT(AVIVO_SEL_DDC2);
+		break;
+	case AVIVO_DC_GPIO_DDC3_MASK:
+		reg |= AVIVO_DC_I2C_PIN_SELECT(AVIVO_SEL_DDC3);
+		break;
+	default:
+		DRM_ERROR("gpio not supported with hw i2c\n");
+		ret = -EINVAL;
+		goto done;
+	}
+
+	/* check for bus probe */
+	p = &msgs[0];
+	if ((num == 1) && (p->len == 0)) {
+		WREG32(AVIVO_DC_I2C_STATUS1, (AVIVO_DC_I2C_DONE |
+					      AVIVO_DC_I2C_NACK |
+					      AVIVO_DC_I2C_HALT));
+		WREG32(AVIVO_DC_I2C_RESET, AVIVO_DC_I2C_SOFT_RESET);
+		udelay(1);
+		WREG32(AVIVO_DC_I2C_RESET, 0);
+
+		WREG32(AVIVO_DC_I2C_DATA, (p->addr << 1) & 0xff);
+		WREG32(AVIVO_DC_I2C_DATA, 0);
+
+		WREG32(AVIVO_DC_I2C_CONTROL3, AVIVO_DC_I2C_TIME_LIMIT(48));
+		WREG32(AVIVO_DC_I2C_CONTROL2, (AVIVO_DC_I2C_ADDR_COUNT(1) |
+					       AVIVO_DC_I2C_DATA_COUNT(1) |
+					       (prescale << 16)));
+		WREG32(AVIVO_DC_I2C_CONTROL1, reg);
+		WREG32(AVIVO_DC_I2C_STATUS1, AVIVO_DC_I2C_GO);
+		for (j = 0; j < 200; j++) {
+			udelay(50);
+			tmp = RREG32(AVIVO_DC_I2C_STATUS1);
+			if (tmp & AVIVO_DC_I2C_GO)
+				continue;
+			tmp = RREG32(AVIVO_DC_I2C_STATUS1);
+			if (tmp & AVIVO_DC_I2C_DONE)
+				break;
+			else {
+				DRM_DEBUG("i2c write error 0x%08x\n", tmp);
+				WREG32(AVIVO_DC_I2C_RESET, AVIVO_DC_I2C_ABORT);
+				ret = -EIO;
+				goto done;
+			}
+		}
+		goto done;
+	}
+
+	for (i = 0; i < num; i++) {
+		p = &msgs[i];
+		remaining = p->len;
+		buffer_offset = 0;
+		if (p->flags & I2C_M_RD) {
+			while (remaining) {
+				if (remaining > 15)
+					current_count = 15;
+				else
+					current_count = remaining;
+				WREG32(AVIVO_DC_I2C_STATUS1, (AVIVO_DC_I2C_DONE |
+							      AVIVO_DC_I2C_NACK |
+							      AVIVO_DC_I2C_HALT));
+				WREG32(AVIVO_DC_I2C_RESET, AVIVO_DC_I2C_SOFT_RESET);
+				udelay(1);
+				WREG32(AVIVO_DC_I2C_RESET, 0);
+
+				WREG32(AVIVO_DC_I2C_DATA, ((p->addr << 1) & 0xff) | 0x1);
+				WREG32(AVIVO_DC_I2C_CONTROL3, AVIVO_DC_I2C_TIME_LIMIT(48));
+				WREG32(AVIVO_DC_I2C_CONTROL2, (AVIVO_DC_I2C_ADDR_COUNT(1) |
+							       AVIVO_DC_I2C_DATA_COUNT(current_count) |
+							       (prescale << 16)));
+				WREG32(AVIVO_DC_I2C_CONTROL1, reg | AVIVO_DC_I2C_RECEIVE);
+				WREG32(AVIVO_DC_I2C_STATUS1, AVIVO_DC_I2C_GO);
+				for (j = 0; j < 200; j++) {
+					udelay(50);
+					tmp = RREG32(AVIVO_DC_I2C_STATUS1);
+					if (tmp & AVIVO_DC_I2C_GO)
+						continue;
+					tmp = RREG32(AVIVO_DC_I2C_STATUS1);
+					if (tmp & AVIVO_DC_I2C_DONE)
+						break;
+					else {
+						DRM_DEBUG("i2c read error 0x%08x\n", tmp);
+						WREG32(AVIVO_DC_I2C_RESET, AVIVO_DC_I2C_ABORT);
+						ret = -EIO;
+						goto done;
+					}
+				}
+				for (j = 0; j < current_count; j++)
+					p->buf[buffer_offset + j] = RREG32(AVIVO_DC_I2C_DATA) & 0xff;
+				remaining -= current_count;
+				buffer_offset += current_count;
+			}
+		} else {
+			while (remaining) {
+				if (remaining > 15)
+					current_count = 15;
+				else
+					current_count = remaining;
+				WREG32(AVIVO_DC_I2C_STATUS1, (AVIVO_DC_I2C_DONE |
+							      AVIVO_DC_I2C_NACK |
+							      AVIVO_DC_I2C_HALT));
+				WREG32(AVIVO_DC_I2C_RESET, AVIVO_DC_I2C_SOFT_RESET);
+				udelay(1);
+				WREG32(AVIVO_DC_I2C_RESET, 0);
+
+				WREG32(AVIVO_DC_I2C_DATA, (p->addr << 1) & 0xff);
+				for (j = 0; j < current_count; j++)
+					WREG32(AVIVO_DC_I2C_DATA, p->buf[buffer_offset + j]);
+
+				WREG32(AVIVO_DC_I2C_CONTROL3, AVIVO_DC_I2C_TIME_LIMIT(48));
+				WREG32(AVIVO_DC_I2C_CONTROL2, (AVIVO_DC_I2C_ADDR_COUNT(1) |
+							       AVIVO_DC_I2C_DATA_COUNT(current_count) |
+							       (prescale << 16)));
+				WREG32(AVIVO_DC_I2C_CONTROL1, reg);
+				WREG32(AVIVO_DC_I2C_STATUS1, AVIVO_DC_I2C_GO);
+				for (j = 0; j < 200; j++) {
+					udelay(50);
+					tmp = RREG32(AVIVO_DC_I2C_STATUS1);
+					if (tmp & AVIVO_DC_I2C_GO)
+						continue;
+					tmp = RREG32(AVIVO_DC_I2C_STATUS1);
+					if (tmp & AVIVO_DC_I2C_DONE)
+						break;
+					else {
+						DRM_DEBUG("i2c write error 0x%08x\n", tmp);
+						WREG32(AVIVO_DC_I2C_RESET, AVIVO_DC_I2C_ABORT);
+						ret = -EIO;
+						goto done;
+					}
+				}
+				remaining -= current_count;
+				buffer_offset += current_count;
+			}
+		}
+	}
+
+done:
+	WREG32(AVIVO_DC_I2C_STATUS1, (AVIVO_DC_I2C_DONE |
+				      AVIVO_DC_I2C_NACK |
+				      AVIVO_DC_I2C_HALT));
+	WREG32(AVIVO_DC_I2C_RESET, AVIVO_DC_I2C_SOFT_RESET);
+	udelay(1);
+	WREG32(AVIVO_DC_I2C_RESET, 0);
+
+	WREG32(AVIVO_DC_I2C_ARBITRATION, AVIVO_DC_I2C_SW_DONE_USING_I2C);
+	WREG32(AVIVO_DC_I2C_CONTROL1, saved1);
+	WREG32(0x494, saved2);
+	tmp = RREG32(RADEON_BIOS_6_SCRATCH);
+	tmp &= ~ATOM_S6_HW_I2C_BUSY_STATE;
+	WREG32(RADEON_BIOS_6_SCRATCH, tmp);
+
+	mutex_unlock(&rdev->dc_hw_i2c_mutex);
+
+	return ret;
+}
+
+static int radeon_sw_i2c_xfer(struct i2c_adapter *i2c_adap,
+			      struct i2c_msg *msgs, int num)
 {
 	struct radeon_i2c_chan *i2c = i2c_get_adapdata(i2c_adap);
 	int ret;
 
 	radeon_i2c_do_lock(i2c, 1);
-	if (i2c_transfer(&i2c->algo.radeon.bit_adapter, msgs, num) == num)
-		ret = num;
-	else
-		ret = -1;
+	ret = i2c_transfer(&i2c->algo.radeon.bit_adapter, msgs, num);
 	radeon_i2c_do_lock(i2c, 0);
 
 	return ret;
 }
 
+static int radeon_i2c_xfer(struct i2c_adapter *i2c_adap,
+			   struct i2c_msg *msgs, int num)
+{
+	struct radeon_i2c_chan *i2c = i2c_get_adapdata(i2c_adap);
+	struct radeon_device *rdev = i2c->dev->dev_private;
+	struct radeon_i2c_bus_rec *rec = &i2c->rec;
+	int ret;
+
+	switch (rdev->family) {
+	case CHIP_R100:
+	case CHIP_RV100:
+	case CHIP_RS100:
+	case CHIP_RV200:
+	case CHIP_RS200:
+	case CHIP_R200:
+	case CHIP_RV250:
+	case CHIP_RS300:
+	case CHIP_RV280:
+	case CHIP_R300:
+	case CHIP_R350:
+	case CHIP_RV350:
+	case CHIP_RV380:
+	case CHIP_R420:
+	case CHIP_R423:
+	case CHIP_RV410:
+	case CHIP_RS400:
+	case CHIP_RS480:
+		if (rec->hw_capable)
+			ret = r100_hw_i2c_xfer(i2c_adap, msgs, num);
+		else
+			ret = radeon_sw_i2c_xfer(i2c_adap, msgs, num);
+		break;
+	case CHIP_RS600:
+	case CHIP_RS690:
+	case CHIP_RS740:
+		/* XXX fill in hw i2c implementation */
+		ret = radeon_sw_i2c_xfer(i2c_adap, msgs, num);
+		break;
+	case CHIP_RV515:
+	case CHIP_R520:
+	case CHIP_RV530:
+	case CHIP_RV560:
+	case CHIP_RV570:
+	case CHIP_R580:
+		if (rec->hw_capable) {
+			if (rec->mm_i2c)
+				ret = r100_hw_i2c_xfer(i2c_adap, msgs, num);
+			else
+				ret = r500_hw_i2c_xfer(i2c_adap, msgs, num);
+		} else
+			ret = radeon_sw_i2c_xfer(i2c_adap, msgs, num);
+		break;
+	case CHIP_R600:
+	case CHIP_RV610:
+	case CHIP_RV630:
+	case CHIP_RV670:
+		/* XXX fill in hw i2c implementation */
+		ret = radeon_sw_i2c_xfer(i2c_adap, msgs, num);
+		break;
+	case CHIP_RV620:
+	case CHIP_RV635:
+	case CHIP_RS780:
+	case CHIP_RS880:
+	case CHIP_RV770:
+	case CHIP_RV730:
+	case CHIP_RV710:
+	case CHIP_RV740:
+		/* XXX fill in hw i2c implementation */
+		ret = radeon_sw_i2c_xfer(i2c_adap, msgs, num);
+		break;
+	default:
+		DRM_ERROR("i2c: unhandled radeon chip\n");
+		ret = -EIO;
+		break;
+	}
+
+	return ret;
+}
+
 static u32 radeon_i2c_func(struct i2c_adapter *adap)
 {
 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
@@ -205,8 +780,6 @@ struct radeon_i2c_chan *radeon_i2c_create(struct drm_device *dev,
 	if (i2c == NULL)
 		return NULL;
 
-	i2c->dev = dev;
-	i2c->rec = *rec;
 	/* set the internal bit adapter */
 	i2c->algo.radeon.bit_adapter.owner = THIS_MODULE;
 	i2c_set_adapdata(&i2c->algo.radeon.bit_adapter, i2c);
@@ -223,10 +796,12 @@ struct radeon_i2c_chan *radeon_i2c_create(struct drm_device *dev,
 	i2c->algo.radeon.bit_data.data = i2c;
 	ret = i2c_bit_add_bus(&i2c->algo.radeon.bit_adapter);
 	if (ret) {
-		DRM_INFO("Failed to register internal bit i2c %s\n", name);
+		DRM_ERROR("Failed to register internal bit i2c %s\n", name);
 		goto out_free;
 	}
 	/* set the radeon i2c adapter */
+	i2c->dev = dev;
+	i2c->rec = *rec;
 	i2c->adapter.owner = THIS_MODULE;
 	i2c_set_adapdata(&i2c->adapter, i2c);
 	sprintf(i2c->adapter.name, "Radeon i2c %s", name);
@@ -234,7 +809,7 @@ struct radeon_i2c_chan *radeon_i2c_create(struct drm_device *dev,
 	i2c->adapter.algo = &radeon_i2c_algo;
 	ret = i2c_add_adapter(&i2c->adapter);
 	if (ret) {
-		DRM_INFO("Failed to register i2c %s\n", name);
+		DRM_ERROR("Failed to register i2c %s\n", name);
 		goto out_free;
 	}
 
diff --git a/drivers/gpu/drm/radeon/radeon_reg.h b/drivers/gpu/drm/radeon/radeon_reg.h
index 6d0a009dd4a..b4a06676fff 100644
--- a/drivers/gpu/drm/radeon/radeon_reg.h
+++ b/drivers/gpu/drm/radeon/radeon_reg.h
@@ -1060,32 +1060,38 @@
 
        /* Multimedia I2C bus */
 #define RADEON_I2C_CNTL_0		    0x0090
-#define RADEON_I2C_DONE                     (1 << 0)
-#define RADEON_I2C_NACK                     (1 << 1)
-#define RADEON_I2C_HALT                     (1 << 2)
-#define RADEON_I2C_SOFT_RST                 (1 << 5)
-#define RADEON_I2C_DRIVE_EN                 (1 << 6)
-#define RADEON_I2C_DRIVE_SEL                (1 << 7)
-#define RADEON_I2C_START                    (1 << 8)
-#define RADEON_I2C_STOP                     (1 << 9)
-#define RADEON_I2C_RECEIVE                  (1 << 10)
-#define RADEON_I2C_ABORT                    (1 << 11)
-#define RADEON_I2C_GO                       (1 << 12)
-#define RADEON_I2C_PRESCALE_SHIFT           16
+#       define RADEON_I2C_DONE              (1 << 0)
+#       define RADEON_I2C_NACK              (1 << 1)
+#       define RADEON_I2C_HALT              (1 << 2)
+#       define RADEON_I2C_SOFT_RST          (1 << 5)
+#       define RADEON_I2C_DRIVE_EN          (1 << 6)
+#       define RADEON_I2C_DRIVE_SEL         (1 << 7)
+#       define RADEON_I2C_START             (1 << 8)
+#       define RADEON_I2C_STOP              (1 << 9)
+#       define RADEON_I2C_RECEIVE           (1 << 10)
+#       define RADEON_I2C_ABORT             (1 << 11)
+#       define RADEON_I2C_GO                (1 << 12)
+#       define RADEON_I2C_PRESCALE_SHIFT    16
 #define RADEON_I2C_CNTL_1                   0x0094
-#define RADEON_I2C_DATA_COUNT_SHIFT         0
-#define RADEON_I2C_ADDR_COUNT_SHIFT         4
-#define RADEON_I2C_INTRA_BYTE_DELAY_SHIFT   8
-#define RADEON_I2C_SEL                      (1 << 16)
-#define RADEON_I2C_EN                       (1 << 17)
-#define RADEON_I2C_TIME_LIMIT_SHIFT         24
+#       define RADEON_I2C_DATA_COUNT_SHIFT  0
+#       define RADEON_I2C_ADDR_COUNT_SHIFT  4
+#       define RADEON_I2C_INTRA_BYTE_DELAY_SHIFT   8
+#       define RADEON_I2C_SEL               (1 << 16)
+#       define RADEON_I2C_EN                (1 << 17)
+#       define RADEON_I2C_TIME_LIMIT_SHIFT  24
 #define RADEON_I2C_DATA			    0x0098
 
 #define RADEON_DVI_I2C_CNTL_0		    0x02e0
 #       define R200_DVI_I2C_PIN_SEL(x)      ((x) << 3)
-#       define R200_SEL_DDC1                0 /* 0x60 - VGA_DDC */
-#       define R200_SEL_DDC2                1 /* 0x64 - DVI_DDC */
-#       define R200_SEL_DDC3                2 /* 0x68 - MONID_DDC */
+#       define R200_SEL_DDC1                0 /* depends on asic */
+#       define R200_SEL_DDC2                1 /* depends on asic */
+#       define R200_SEL_DDC3                2 /* depends on asic */
+#	define RADEON_SW_WANTS_TO_USE_DVI_I2C (1 << 13)
+#	define RADEON_SW_CAN_USE_DVI_I2C      (1 << 13)
+#	define RADEON_SW_DONE_USING_DVI_I2C   (1 << 14)
+#	define RADEON_HW_NEEDS_DVI_I2C        (1 << 14)
+#	define RADEON_ABORT_HW_DVI_I2C        (1 << 15)
+#	define RADEON_HW_USING_DVI_I2C        (1 << 15)
 #define RADEON_DVI_I2C_CNTL_1               0x02e4
 #define RADEON_DVI_I2C_DATA		    0x02e8