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>

1 files changed, 586 insertions, 11 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_i2c.c b/drivers/gpu/drm/radeon/radeon_i2c.c
index 75b090f60208..b47a5615fe6a 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;
 	}