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-rw-r--r--drivers/gpu/drm/i915/i915_reg.h1
-rw-r--r--drivers/gpu/drm/i915/intel_i2c.c66
2 files changed, 57 insertions, 10 deletions
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index b522eb6e59a4..3da1af46625c 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -1807,6 +1807,7 @@ enum skl_disp_power_wells {
#define GMBUS_CYCLE_INDEX (2<<25)
#define GMBUS_CYCLE_STOP (4<<25)
#define GMBUS_BYTE_COUNT_SHIFT 16
+#define GMBUS_BYTE_COUNT_MAX 256U
#define GMBUS_SLAVE_INDEX_SHIFT 8
#define GMBUS_SLAVE_ADDR_SHIFT 1
#define GMBUS_SLAVE_READ (1<<0)
diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c
index b31088a551f2..56e437e31580 100644
--- a/drivers/gpu/drm/i915/intel_i2c.c
+++ b/drivers/gpu/drm/i915/intel_i2c.c
@@ -270,18 +270,17 @@ gmbus_wait_idle(struct drm_i915_private *dev_priv)
}
static int
-gmbus_xfer_read(struct drm_i915_private *dev_priv, struct i2c_msg *msg,
- u32 gmbus1_index)
+gmbus_xfer_read_chunk(struct drm_i915_private *dev_priv,
+ unsigned short addr, u8 *buf, unsigned int len,
+ u32 gmbus1_index)
{
int reg_offset = dev_priv->gpio_mmio_base;
- u16 len = msg->len;
- u8 *buf = msg->buf;
I915_WRITE(GMBUS1 + reg_offset,
gmbus1_index |
GMBUS_CYCLE_WAIT |
(len << GMBUS_BYTE_COUNT_SHIFT) |
- (msg->addr << GMBUS_SLAVE_ADDR_SHIFT) |
+ (addr << GMBUS_SLAVE_ADDR_SHIFT) |
GMBUS_SLAVE_READ | GMBUS_SW_RDY);
while (len) {
int ret;
@@ -303,11 +302,35 @@ gmbus_xfer_read(struct drm_i915_private *dev_priv, struct i2c_msg *msg,
}
static int
-gmbus_xfer_write(struct drm_i915_private *dev_priv, struct i2c_msg *msg)
+gmbus_xfer_read(struct drm_i915_private *dev_priv, struct i2c_msg *msg,
+ u32 gmbus1_index)
{
- int reg_offset = dev_priv->gpio_mmio_base;
- u16 len = msg->len;
u8 *buf = msg->buf;
+ unsigned int rx_size = msg->len;
+ unsigned int len;
+ int ret;
+
+ do {
+ len = min(rx_size, GMBUS_BYTE_COUNT_MAX);
+
+ ret = gmbus_xfer_read_chunk(dev_priv, msg->addr,
+ buf, len, gmbus1_index);
+ if (ret)
+ return ret;
+
+ rx_size -= len;
+ buf += len;
+ } while (rx_size != 0);
+
+ return 0;
+}
+
+static int
+gmbus_xfer_write_chunk(struct drm_i915_private *dev_priv,
+ unsigned short addr, u8 *buf, unsigned int len)
+{
+ int reg_offset = dev_priv->gpio_mmio_base;
+ unsigned int chunk_size = len;
u32 val, loop;
val = loop = 0;
@@ -319,8 +342,8 @@ gmbus_xfer_write(struct drm_i915_private *dev_priv, struct i2c_msg *msg)
I915_WRITE(GMBUS3 + reg_offset, val);
I915_WRITE(GMBUS1 + reg_offset,
GMBUS_CYCLE_WAIT |
- (msg->len << GMBUS_BYTE_COUNT_SHIFT) |
- (msg->addr << GMBUS_SLAVE_ADDR_SHIFT) |
+ (chunk_size << GMBUS_BYTE_COUNT_SHIFT) |
+ (addr << GMBUS_SLAVE_ADDR_SHIFT) |
GMBUS_SLAVE_WRITE | GMBUS_SW_RDY);
while (len) {
int ret;
@@ -337,6 +360,29 @@ gmbus_xfer_write(struct drm_i915_private *dev_priv, struct i2c_msg *msg)
if (ret)
return ret;
}
+
+ return 0;
+}
+
+static int
+gmbus_xfer_write(struct drm_i915_private *dev_priv, struct i2c_msg *msg)
+{
+ u8 *buf = msg->buf;
+ unsigned int tx_size = msg->len;
+ unsigned int len;
+ int ret;
+
+ do {
+ len = min(tx_size, GMBUS_BYTE_COUNT_MAX);
+
+ ret = gmbus_xfer_write_chunk(dev_priv, msg->addr, buf, len);
+ if (ret)
+ return ret;
+
+ buf += len;
+ tx_size -= len;
+ } while (tx_size != 0);
+
return 0;
}