diff options
Diffstat (limited to 'drivers/gpu/drm/i915/intel_i2c.c')
| -rw-r--r-- | 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 0713cc289119..30675ce18056 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; |