[PATCH 01/14 v5] drm/i915/intel_i2c: refactor gmbus_xfer

Daniel Kurtz
2012-03-28T12:52:12Z

Split out gmbus_xfer_read/write() helper functions.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
---
drivers/gpu/drm/i915/intel_i2c.c | 151 +++++++++++++++++++++++---------------
1 files changed, 92 insertions(+), 59 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c
index 0713cc2..30675ce 100644
--- a/drivers/gpu/drm/i915/intel_i2c.c
+++ b/drivers/gpu/drm/i915/intel_i2c.c
@@ -198,6 +198,82 @@ intel_i2c_quirk_xfer(struct intel_gmbus *bus,
}

static int
+gmbus_xfer_read(struct drm_i915_private *dev_priv, struct i2c_msg *msg,
+ bool last)
+{
+ int reg_offset = dev_priv->gpio_mmio_base;
+ u16 len = msg->len;
+ u8 *buf = msg->buf;
+
+ I915_WRITE(GMBUS1 + reg_offset,
+ GMBUS_CYCLE_WAIT |
+ (last ? GMBUS_CYCLE_STOP : 0) |
+ (len << GMBUS_BYTE_COUNT_SHIFT) |
+ (msg->addr << GMBUS_SLAVE_ADDR_SHIFT) |
+ GMBUS_SLAVE_READ | GMBUS_SW_RDY);
+ POSTING_READ(GMBUS2 + reg_offset);
+ do {
+ u32 val, loop = 0;
+
+ if (wait_for(I915_READ(GMBUS2 + reg_offset) &
+ (GMBUS_SATOER | GMBUS_HW_RDY),
+ 50))
+ return -ETIMEDOUT;
+ if (I915_READ(GMBUS2 + reg_offset) & GMBUS_SATOER)
+ return -ENXIO;
+
+ val = I915_READ(GMBUS3 + reg_offset);
+ do {
+ *buf++ = val & 0xff;
+ val >>= 8;
+ } while (--len && ++loop < 4);
+ } while (len);
+
+ return 0;
+}
+
+static int
+gmbus_xfer_write(struct drm_i915_private *dev_priv, struct i2c_msg *msg,
+ bool last)
+{
+ int reg_offset = dev_priv->gpio_mmio_base;
+ u16 len = msg->len;
+ u8 *buf = msg->buf;
+ u32 val, loop;
+
+ val = loop = 0;
+ do {
+ val |= *buf++ << (8 * loop);
+ } while (--len && ++loop < 4);
+
+ I915_WRITE(GMBUS3 + reg_offset, val);
+ I915_WRITE(GMBUS1 + reg_offset,
+ GMBUS_CYCLE_WAIT |
+ (last ? GMBUS_CYCLE_STOP : 0) |
+ (msg->len << GMBUS_BYTE_COUNT_SHIFT) |
+ (msg->addr << GMBUS_SLAVE_ADDR_SHIFT) |
+ GMBUS_SLAVE_WRITE | GMBUS_SW_RDY);
+ POSTING_READ(GMBUS2 + reg_offset);
+ while (len) {
+ if (wait_for(I915_READ(GMBUS2 + reg_offset) &
+ (GMBUS_SATOER | GMBUS_HW_RDY),
+ 50))
+ return -ETIMEDOUT;
+ if (I915_READ(GMBUS2 + reg_offset) & GMBUS_SATOER)
+ return -ENXIO;
+
+ val = loop = 0;
+ do {
+ val |= *buf++ << (8 * loop);
+ } while (--len && ++loop < 4);
+
+ I915_WRITE(GMBUS3 + reg_offset, val);
+ POSTING_READ(GMBUS2 + reg_offset);
+ }
+ return 0;
+}
+
+static int
gmbus_xfer(struct i2c_adapter *adapter,
struct i2c_msg *msgs,
int num)
@@ -220,65 +296,22 @@ gmbus_xfer(struct i2c_adapter *adapter,
I915_WRITE(GMBUS0 + reg_offset, bus->reg0);

for (i = 0; i < num; i++) {
- u16 len = msgs[i].len;
- u8 *buf = msgs[i].buf;
-
- if (msgs[i].flags & I2C_M_RD) {
- I915_WRITE(GMBUS1 + reg_offset,
- GMBUS_CYCLE_WAIT |
- (i + 1 == num ? GMBUS_CYCLE_STOP : 0) |
- (len << GMBUS_BYTE_COUNT_SHIFT) |
- (msgs[i].addr << GMBUS_SLAVE_ADDR_SHIFT) |
- GMBUS_SLAVE_READ | GMBUS_SW_RDY);
- POSTING_READ(GMBUS2+reg_offset);
- do {
- u32 val, loop = 0;
-
- if (wait_for(I915_READ(GMBUS2 + reg_offset) & (GMBUS_SATOER | GMBUS_HW_RDY), 50))
- goto timeout;
- if (I915_READ(GMBUS2 + reg_offset) & GMBUS_SATOER)
- goto clear_err;
-
- val = I915_READ(GMBUS3 + reg_offset);
- do {
- *buf++ = val & 0xff;
- val >>= 8;
- } while (--len && ++loop < 4);
- } while (len);
- } else {
- u32 val, loop;
-
- val = loop = 0;
- do {
- val |= *buf++ << (8 * loop);
- } while (--len && ++loop < 4);
-
- I915_WRITE(GMBUS3 + reg_offset, val);
- I915_WRITE(GMBUS1 + reg_offset,
- GMBUS_CYCLE_WAIT |
- (i + 1 == num ? GMBUS_CYCLE_STOP : 0) |
- (msgs[i].len << GMBUS_BYTE_COUNT_SHIFT) |
- (msgs[i].addr << GMBUS_SLAVE_ADDR_SHIFT) |
- GMBUS_SLAVE_WRITE | GMBUS_SW_RDY);
- POSTING_READ(GMBUS2+reg_offset);
-
- while (len) {
- if (wait_for(I915_READ(GMBUS2 + reg_offset) & (GMBUS_SATOER | GMBUS_HW_RDY), 50))
- goto timeout;
- if (I915_READ(GMBUS2 + reg_offset) & GMBUS_SATOER)
- goto clear_err;
-
- val = loop = 0;
- do {
- val |= *buf++ << (8 * loop);
- } while (--len && ++loop < 4);
-
- I915_WRITE(GMBUS3 + reg_offset, val);
- POSTING_READ(GMBUS2+reg_offset);
- }
- }
-
- if (i + 1 < num && wait_for(I915_READ(GMBUS2 + reg_offset) & (GMBUS_SATOER | GMBUS_HW_WAIT_PHASE), 50))
+ bool last = i + 1 == num;
+
+ if (msgs[i].flags & I2C_M_RD)
+ ret = gmbus_xfer_read(dev_priv, &msgs[i], last);
+ else
+ ret = gmbus_xfer_write(dev_priv, &msgs[i], last);
+
+ if (ret == -ETIMEDOUT)
+ goto timeout;
+ if (ret == -ENXIO)
+ goto clear_err;
+
+ if (!last &&
+ wait_for(I915_READ(GMBUS2 + reg_offset) &
+ (GMBUS_SATOER | GMBUS_HW_WAIT_PHASE),
+ 50))
goto timeout;
if (I915_READ(GMBUS2 + reg_offset) & GMBUS_SATOER)
goto clear_err;
--
1.7.7.3