[PATCH v2 7/9] i2c: designware: Move interrupt handling functions before i2c_dw_xfer()

Jarkko Nikula
2024-02-06T14:52:27Z

Code is more logically arranged when i2c_dw_read_clear_intrbits() and
i2c_dw_isr() are located before i2c_dw_xfer().

Real reason for this is to prepare for more shared code between
interrupt and polling mode code.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
---
drivers/i2c/busses/i2c-designware-master.c | 226 ++++++++++-----------
1 file changed, 113 insertions(+), 113 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
index 2e8f9733ddd3..856c955c6560 100644
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -633,119 +633,6 @@ i2c_dw_read(struct dw_i2c_dev *dev)
}
}

-/*
- * Prepare controller for a transaction and call i2c_dw_xfer_msg.
- */
-static int
-i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
-{
- struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
- int ret;
-
- dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
-
- pm_runtime_get_sync(dev->dev);
-
- /*
- * Initiate I2C message transfer when polling mode is enabled,
- * As it is polling based transfer mechanism, which does not support
- * interrupt based functionalities of existing DesignWare driver.
- */
- switch (dev->flags & MODEL_MASK) {
- case MODEL_AMD_NAVI_GPU:
- ret = amd_i2c_dw_xfer_quirk(adap, msgs, num);
- goto done_nolock;
- case MODEL_WANGXUN_SP:
- ret = txgbe_i2c_dw_xfer_quirk(adap, msgs, num);
- goto done_nolock;
- default:
- break;
- }
-
- reinit_completion(&dev->cmd_complete);
- dev->msgs = msgs;
- dev->msgs_num = num;
- dev->cmd_err = 0;
- dev->msg_write_idx = 0;
- dev->msg_read_idx = 0;
- dev->msg_err = 0;
- dev->status = 0;
- dev->abort_source = 0;
- dev->rx_outstanding = 0;
-
- ret = i2c_dw_acquire_lock(dev);
- if (ret)
- goto done_nolock;
-
- ret = i2c_dw_wait_bus_not_busy(dev);
- if (ret < 0)
- goto done;
-
- /* Start the transfers */
- i2c_dw_xfer_init(dev);
-
- /* Wait for tx to complete */
- if (!wait_for_completion_timeout(&dev->cmd_complete, adap->timeout)) {
- dev_err(dev->dev, "controller timed out\n");
- /* i2c_dw_init implicitly disables the adapter */
- i2c_recover_bus(&dev->adapter);
- i2c_dw_init_master(dev);
- ret = -ETIMEDOUT;
- goto done;
- }
-
- /*
- * We must disable the adapter before returning and signaling the end
- * of the current transfer. Otherwise the hardware might continue
- * generating interrupts which in turn causes a race condition with
- * the following transfer. Needs some more investigation if the
- * additional interrupts are a hardware bug or this driver doesn't
- * handle them correctly yet.
- */
- __i2c_dw_disable_nowait(dev);
-
- if (dev->msg_err) {
- ret = dev->msg_err;
- goto done;
- }
-
- /* No error */
- if (likely(!dev->cmd_err && !dev->status)) {
- ret = num;
- goto done;
- }
-
- /* We have an error */
- if (dev->cmd_err == DW_IC_ERR_TX_ABRT) {
- ret = i2c_dw_handle_tx_abort(dev);
- goto done;
- }
-
- if (dev->status)
- dev_err(dev->dev,
- "transfer terminated early - interrupt latency too high?\n");
-
- ret = -EIO;
-
-done:
- i2c_dw_release_lock(dev);
-
-done_nolock:
- pm_runtime_mark_last_busy(dev->dev);
- pm_runtime_put_autosuspend(dev->dev);
-
- return ret;
-}
-
-static const struct i2c_algorithm i2c_dw_algo = {
- .master_xfer = i2c_dw_xfer,
- .functionality = i2c_dw_func,
-};
-
-static const struct i2c_adapter_quirks i2c_dw_quirks = {
- .flags = I2C_AQ_NO_ZERO_LEN,
-};
-
static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev)
{
unsigned int stat, dummy;
@@ -872,6 +759,119 @@ static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
return IRQ_HANDLED;
}

+/*
+ * Prepare controller for a transaction and call i2c_dw_xfer_msg.
+ */
+static int
+i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
+{
+ struct dw_i2c_dev *dev = i2c_get_adapdata(adap);
+ int ret;
+
+ dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);
+
+ pm_runtime_get_sync(dev->dev);
+
+ /*
+ * Initiate I2C message transfer when polling mode is enabled,
+ * As it is polling based transfer mechanism, which does not support
+ * interrupt based functionalities of existing DesignWare driver.
+ */
+ switch (dev->flags & MODEL_MASK) {
+ case MODEL_AMD_NAVI_GPU:
+ ret = amd_i2c_dw_xfer_quirk(adap, msgs, num);
+ goto done_nolock;
+ case MODEL_WANGXUN_SP:
+ ret = txgbe_i2c_dw_xfer_quirk(adap, msgs, num);
+ goto done_nolock;
+ default:
+ break;
+ }
+
+ reinit_completion(&dev->cmd_complete);
+ dev->msgs = msgs;
+ dev->msgs_num = num;
+ dev->cmd_err = 0;
+ dev->msg_write_idx = 0;
+ dev->msg_read_idx = 0;
+ dev->msg_err = 0;
+ dev->status = 0;
+ dev->abort_source = 0;
+ dev->rx_outstanding = 0;
+
+ ret = i2c_dw_acquire_lock(dev);
+ if (ret)
+ goto done_nolock;
+
+ ret = i2c_dw_wait_bus_not_busy(dev);
+ if (ret < 0)
+ goto done;
+
+ /* Start the transfers */
+ i2c_dw_xfer_init(dev);
+
+ /* Wait for tx to complete */
+ if (!wait_for_completion_timeout(&dev->cmd_complete, adap->timeout)) {
+ dev_err(dev->dev, "controller timed out\n");
+ /* i2c_dw_init implicitly disables the adapter */
+ i2c_recover_bus(&dev->adapter);
+ i2c_dw_init_master(dev);
+ ret = -ETIMEDOUT;
+ goto done;
+ }
+
+ /*
+ * We must disable the adapter before returning and signaling the end
+ * of the current transfer. Otherwise the hardware might continue
+ * generating interrupts which in turn causes a race condition with
+ * the following transfer. Needs some more investigation if the
+ * additional interrupts are a hardware bug or this driver doesn't
+ * handle them correctly yet.
+ */
+ __i2c_dw_disable_nowait(dev);
+
+ if (dev->msg_err) {
+ ret = dev->msg_err;
+ goto done;
+ }
+
+ /* No error */
+ if (likely(!dev->cmd_err && !dev->status)) {
+ ret = num;
+ goto done;
+ }
+
+ /* We have an error */
+ if (dev->cmd_err == DW_IC_ERR_TX_ABRT) {
+ ret = i2c_dw_handle_tx_abort(dev);
+ goto done;
+ }
+
+ if (dev->status)
+ dev_err(dev->dev,
+ "transfer terminated early - interrupt latency too high?\n");
+
+ ret = -EIO;
+
+done:
+ i2c_dw_release_lock(dev);
+
+done_nolock:
+ pm_runtime_mark_last_busy(dev->dev);
+ pm_runtime_put_autosuspend(dev->dev);
+
+ return ret;
+}
+
+static const struct i2c_algorithm i2c_dw_algo = {
+ .master_xfer = i2c_dw_xfer,
+ .functionality = i2c_dw_func,
+};
+
+static const struct i2c_adapter_quirks i2c_dw_quirks = {
+ .flags = I2C_AQ_NO_ZERO_LEN,
+};
+
void i2c_dw_configure_master(struct dw_i2c_dev *dev)
{
struct i2c_timings *t = &dev->timings;
--
2.43.0