1 files changed, 224 insertions, 24 deletions

diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
index 43fdd89b8beb..3a04016db2c3 100644
--- a/drivers/i2c/busses/i2c-qcom-geni.c
+++ b/drivers/i2c/busses/i2c-qcom-geni.c
@@ -77,6 +77,25 @@ enum geni_i2c_err_code {
 #define XFER_TIMEOUT		HZ
 #define RST_TIMEOUT		HZ
 
+#define QCOM_I2C_MIN_NUM_OF_MSGS_MULTI_DESC	2
+
+/**
+ * struct geni_i2c_gpi_multi_desc_xfer - Structure for multi transfer support
+ *
+ * @msg_idx_cnt: Current message index being processed in the transfer
+ * @unmap_msg_cnt: Number of messages that have been unmapped
+ * @irq_cnt: Number of transfer completion interrupts received
+ * @dma_buf: Array of virtual addresses for DMA-safe buffers
+ * @dma_addr: Array of DMA addresses corresponding to the buffers
+ */
+struct geni_i2c_gpi_multi_desc_xfer {
+	u32 msg_idx_cnt;
+	u32 unmap_msg_cnt;
+	u32 irq_cnt;
+	void **dma_buf;
+	dma_addr_t *dma_addr;
+};
+
 struct geni_i2c_dev {
 	struct geni_se se;
 	u32 tx_wm;
@@ -99,6 +118,9 @@ struct geni_i2c_dev {
 	struct dma_chan *rx_c;
 	bool gpi_mode;
 	bool abort_done;
+	bool is_tx_multi_desc_xfer;
+	u32 num_msgs;
+	struct geni_i2c_gpi_multi_desc_xfer i2c_multi_desc_config;
 };
 
 struct geni_i2c_desc {
@@ -499,6 +521,7 @@ static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
 static void i2c_gpi_cb_result(void *cb, const struct dmaengine_result *result)
 {
 	struct geni_i2c_dev *gi2c = cb;
+	struct geni_i2c_gpi_multi_desc_xfer *tx_multi_xfer;
 
 	if (result->result != DMA_TRANS_NOERROR) {
 		dev_err(gi2c->se.dev, "DMA txn failed:%d\n", result->result);
@@ -507,6 +530,11 @@ static void i2c_gpi_cb_result(void *cb, const struct dmaengine_result *result)
 		dev_dbg(gi2c->se.dev, "DMA xfer has pending: %d\n", result->residue);
 	}
 
+	if (gi2c->is_tx_multi_desc_xfer) {
+		tx_multi_xfer = &gi2c->i2c_multi_desc_config;
+		tx_multi_xfer->irq_cnt++;
+	}
+
 	complete(&gi2c->done);
 }
 
@@ -525,7 +553,72 @@ static void geni_i2c_gpi_unmap(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
 	}
 }
 
-static int geni_i2c_gpi(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
+/**
+ * geni_i2c_gpi_multi_desc_unmap() - Unmaps DMA buffers post multi message TX transfers
+ * @gi2c: I2C dev handle
+ * @msgs: Array of I2C  messages
+ * @peripheral: Pointer to gpi_i2c_config
+ */
+static void geni_i2c_gpi_multi_desc_unmap(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[],
+					  struct gpi_i2c_config *peripheral)
+{
+	u32 msg_xfer_cnt, wr_idx = 0;
+	struct geni_i2c_gpi_multi_desc_xfer *tx_multi_xfer = &gi2c->i2c_multi_desc_config;
+
+	msg_xfer_cnt = gi2c->err ? tx_multi_xfer->msg_idx_cnt : tx_multi_xfer->irq_cnt;
+
+	/* Unmap the processed DMA buffers based on the received interrupt count */
+	for (; tx_multi_xfer->unmap_msg_cnt < msg_xfer_cnt; tx_multi_xfer->unmap_msg_cnt++) {
+		wr_idx = tx_multi_xfer->unmap_msg_cnt;
+		geni_i2c_gpi_unmap(gi2c, &msgs[wr_idx],
+				   tx_multi_xfer->dma_buf[wr_idx],
+				   tx_multi_xfer->dma_addr[wr_idx],
+				   NULL, 0);
+
+		if (tx_multi_xfer->unmap_msg_cnt == gi2c->num_msgs - 1) {
+			kfree(tx_multi_xfer->dma_buf);
+			kfree(tx_multi_xfer->dma_addr);
+			break;
+		}
+	}
+}
+
+/**
+ * geni_i2c_gpi_multi_xfer_timeout_handler() - Handles multi message transfer timeout
+ * @dev: Pointer to the corresponding dev node
+ * @multi_xfer: Pointer to the geni_i2c_gpi_multi_desc_xfer
+ * @transfer_timeout_msecs: Timeout value in milliseconds
+ * @transfer_comp: Completion object of the transfer
+ *
+ * This function waits for the completion of each processed transfer messages
+ * based on the interrupts generated upon transfer completion.
+ *
+ * Return: On success returns 0, -ETIMEDOUT on timeout.
+ */
+static int geni_i2c_gpi_multi_xfer_timeout_handler(struct device *dev,
+						   struct geni_i2c_gpi_multi_desc_xfer *multi_xfer,
+						   u32 transfer_timeout_msecs,
+						   struct completion *transfer_comp)
+{
+	int i;
+	u32 time_left;
+
+	for (i = 0; i < multi_xfer->msg_idx_cnt - 1; i++) {
+		reinit_completion(transfer_comp);
+
+		if (multi_xfer->msg_idx_cnt != multi_xfer->irq_cnt) {
+			time_left = wait_for_completion_timeout(transfer_comp,
+								transfer_timeout_msecs);
+			if (!time_left) {
+				dev_err(dev, "%s: Transfer timeout\n", __func__);
+				return -ETIMEDOUT;
+			}
+		}
+	}
+	return 0;
+}
+
+static int geni_i2c_gpi(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[],
 			struct dma_slave_config *config, dma_addr_t *dma_addr_p,
 			void **buf, unsigned int op, struct dma_chan *dma_chan)
 {
@@ -537,26 +630,45 @@ static int geni_i2c_gpi(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
 	enum dma_transfer_direction dma_dirn;
 	struct dma_async_tx_descriptor *desc;
 	int ret;
+	struct geni_i2c_gpi_multi_desc_xfer *gi2c_gpi_xfer;
+	dma_cookie_t cookie;
+	u32 msg_idx;
 
 	peripheral = config->peripheral_config;
+	gi2c_gpi_xfer = &gi2c->i2c_multi_desc_config;
+	msg_idx = gi2c_gpi_xfer->msg_idx_cnt;
 
-	dma_buf = i2c_get_dma_safe_msg_buf(msg, 1);
-	if (!dma_buf)
-		return -ENOMEM;
+	dma_buf = i2c_get_dma_safe_msg_buf(&msgs[msg_idx], 1);
+	if (!dma_buf) {
+		ret = -ENOMEM;
+		goto out;
+	}
 
 	if (op == I2C_WRITE)
 		map_dirn = DMA_TO_DEVICE;
 	else
 		map_dirn = DMA_FROM_DEVICE;
 
-	addr = dma_map_single(gi2c->se.dev->parent, dma_buf, msg->len, map_dirn);
+	addr = dma_map_single(gi2c->se.dev->parent, dma_buf,
+			      msgs[msg_idx].len, map_dirn);
 	if (dma_mapping_error(gi2c->se.dev->parent, addr)) {
-		i2c_put_dma_safe_msg_buf(dma_buf, msg, false);
-		return -ENOMEM;
+		i2c_put_dma_safe_msg_buf(dma_buf, &msgs[msg_idx], false);
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	if (gi2c->is_tx_multi_desc_xfer) {
+		flags = DMA_CTRL_ACK;
+
+		/* BEI bit to be cleared for last TRE */
+		if (msg_idx == gi2c->num_msgs - 1)
+			flags |= DMA_PREP_INTERRUPT;
+	} else {
+		flags = DMA_PREP_INTERRUPT | DMA_CTRL_ACK;
 	}
 
 	/* set the length as message for rx txn */
-	peripheral->rx_len = msg->len;
+	peripheral->rx_len = msgs[msg_idx].len;
 	peripheral->op = op;
 
 	ret = dmaengine_slave_config(dma_chan, config);
@@ -567,14 +679,21 @@ static int geni_i2c_gpi(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
 
 	peripheral->set_config = 0;
 	peripheral->multi_msg = true;
-	flags = DMA_PREP_INTERRUPT | DMA_CTRL_ACK;
 
 	if (op == I2C_WRITE)
 		dma_dirn = DMA_MEM_TO_DEV;
 	else
 		dma_dirn = DMA_DEV_TO_MEM;
 
-	desc = dmaengine_prep_slave_single(dma_chan, addr, msg->len, dma_dirn, flags);
+	desc = dmaengine_prep_slave_single(dma_chan, addr, msgs[msg_idx].len,
+					   dma_dirn, flags);
+	if (!desc && !(flags & DMA_PREP_INTERRUPT)) {
+		/* Retry with interrupt if not enough TREs */
+		flags |= DMA_PREP_INTERRUPT;
+		desc = dmaengine_prep_slave_single(dma_chan, addr, msgs[msg_idx].len,
+						   dma_dirn, flags);
+	}
+
 	if (!desc) {
 		dev_err(gi2c->se.dev, "prep_slave_sg failed\n");
 		ret = -EIO;
@@ -584,15 +703,48 @@ static int geni_i2c_gpi(struct geni_i2c_dev *gi2c, struct i2c_msg *msg,
 	desc->callback_result = i2c_gpi_cb_result;
 	desc->callback_param = gi2c;
 
-	dmaengine_submit(desc);
-	*buf = dma_buf;
-	*dma_addr_p = addr;
+	if (!((msgs[msg_idx].flags & I2C_M_RD) && op == I2C_WRITE))
+		gi2c_gpi_xfer->msg_idx_cnt++;
 
+	cookie = dmaengine_submit(desc);
+	if (dma_submit_error(cookie)) {
+		dev_err(gi2c->se.dev,
+			"%s: dmaengine_submit failed (%d)\n", __func__, cookie);
+		ret = -EINVAL;
+		goto err_config;
+	}
+
+	if (gi2c->is_tx_multi_desc_xfer) {
+		gi2c_gpi_xfer->dma_buf[msg_idx] = dma_buf;
+		gi2c_gpi_xfer->dma_addr[msg_idx] = addr;
+
+		dma_async_issue_pending(gi2c->tx_c);
+
+		if ((msg_idx == (gi2c->num_msgs - 1)) || flags & DMA_PREP_INTERRUPT) {
+			ret = geni_i2c_gpi_multi_xfer_timeout_handler(gi2c->se.dev, gi2c_gpi_xfer,
+								      XFER_TIMEOUT, &gi2c->done);
+			if (ret) {
+				dev_err(gi2c->se.dev,
+					"I2C multi write msg transfer timeout: %d\n",
+					ret);
+				gi2c->err = ret;
+				return ret;
+			}
+		}
+	} else {
+		/* Non multi descriptor message transfer */
+		*buf = dma_buf;
+		*dma_addr_p = addr;
+	}
 	return 0;
 
 err_config:
-	dma_unmap_single(gi2c->se.dev->parent, addr, msg->len, map_dirn);
-	i2c_put_dma_safe_msg_buf(dma_buf, msg, false);
+	dma_unmap_single(gi2c->se.dev->parent, addr,
+			 msgs[msg_idx].len, map_dirn);
+	i2c_put_dma_safe_msg_buf(dma_buf, &msgs[msg_idx], false);
+
+out:
+	gi2c->err = ret;
 	return ret;
 }
 
@@ -604,6 +756,7 @@ static int geni_i2c_gpi_xfer(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[], i
 	unsigned long time_left;
 	dma_addr_t tx_addr, rx_addr;
 	void *tx_buf = NULL, *rx_buf = NULL;
+	struct geni_i2c_gpi_multi_desc_xfer *tx_multi_xfer;
 	const struct geni_i2c_clk_fld *itr = gi2c->clk_fld;
 
 	config.peripheral_config = &peripheral;
@@ -617,6 +770,41 @@ static int geni_i2c_gpi_xfer(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[], i
 	peripheral.set_config = 1;
 	peripheral.multi_msg = false;
 
+	gi2c->num_msgs = num;
+	gi2c->is_tx_multi_desc_xfer = false;
+
+	tx_multi_xfer = &gi2c->i2c_multi_desc_config;
+	memset(tx_multi_xfer, 0, sizeof(struct geni_i2c_gpi_multi_desc_xfer));
+
+	/*
+	 * If number of write messages are two and higher then
+	 * configure hardware for multi descriptor transfers with BEI.
+	 */
+	if (num >= QCOM_I2C_MIN_NUM_OF_MSGS_MULTI_DESC) {
+		gi2c->is_tx_multi_desc_xfer = true;
+		for (i = 0; i < num; i++) {
+			if (msgs[i].flags & I2C_M_RD) {
+				/*
+				 * Multi descriptor transfer with BEI
+				 * support is enabled for write transfers.
+				 * TODO: Add BEI optimization support for
+				 * read transfers later.
+				 */
+				gi2c->is_tx_multi_desc_xfer = false;
+				break;
+			}
+		}
+	}
+
+	if (gi2c->is_tx_multi_desc_xfer) {
+		tx_multi_xfer->dma_buf = kcalloc(num, sizeof(void *), GFP_KERNEL);
+		tx_multi_xfer->dma_addr = kcalloc(num, sizeof(dma_addr_t), GFP_KERNEL);
+		if (!tx_multi_xfer->dma_buf || !tx_multi_xfer->dma_addr) {
+			ret = -ENOMEM;
+			goto err;
+		}
+	}
+
 	for (i = 0; i < num; i++) {
 		gi2c->cur = &msgs[i];
 		gi2c->err = 0;
@@ -627,14 +815,16 @@ static int geni_i2c_gpi_xfer(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[], i
 			peripheral.stretch = 1;
 
 		peripheral.addr = msgs[i].addr;
+		if (i > 0 && (!(msgs[i].flags & I2C_M_RD)))
+			peripheral.multi_msg = false;
 
-		ret =  geni_i2c_gpi(gi2c, &msgs[i], &config,
+		ret =  geni_i2c_gpi(gi2c, msgs, &config,
 				    &tx_addr, &tx_buf, I2C_WRITE, gi2c->tx_c);
 		if (ret)
 			goto err;
 
 		if (msgs[i].flags & I2C_M_RD) {
-			ret =  geni_i2c_gpi(gi2c, &msgs[i], &config,
+			ret =  geni_i2c_gpi(gi2c, msgs, &config,
 					    &rx_addr, &rx_buf, I2C_READ, gi2c->rx_c);
 			if (ret)
 				goto err;
@@ -642,18 +832,24 @@ static int geni_i2c_gpi_xfer(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[], i
 			dma_async_issue_pending(gi2c->rx_c);
 		}
 
-		dma_async_issue_pending(gi2c->tx_c);
-
-		time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
-		if (!time_left)
-			gi2c->err = -ETIMEDOUT;
+		if (!gi2c->is_tx_multi_desc_xfer) {
+			dma_async_issue_pending(gi2c->tx_c);
+			time_left = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT);
+			if (!time_left) {
+				dev_err(gi2c->se.dev, "%s:I2C timeout\n", __func__);
+				gi2c->err = -ETIMEDOUT;
+			}
+		}
 
 		if (gi2c->err) {
 			ret = gi2c->err;
 			goto err;
 		}
 
-		geni_i2c_gpi_unmap(gi2c, &msgs[i], tx_buf, tx_addr, rx_buf, rx_addr);
+		if (!gi2c->is_tx_multi_desc_xfer)
+			geni_i2c_gpi_unmap(gi2c, &msgs[i], tx_buf, tx_addr, rx_buf, rx_addr);
+		else if (tx_multi_xfer->unmap_msg_cnt != tx_multi_xfer->irq_cnt)
+			geni_i2c_gpi_multi_desc_unmap(gi2c, msgs, &peripheral);
 	}
 
 	return num;
@@ -662,7 +858,11 @@ err:
 	dev_err(gi2c->se.dev, "GPI transfer failed: %d\n", ret);
 	dmaengine_terminate_sync(gi2c->rx_c);
 	dmaengine_terminate_sync(gi2c->tx_c);
-	geni_i2c_gpi_unmap(gi2c, &msgs[i], tx_buf, tx_addr, rx_buf, rx_addr);
+	if (gi2c->is_tx_multi_desc_xfer)
+		geni_i2c_gpi_multi_desc_unmap(gi2c, msgs, &peripheral);
+	else
+		geni_i2c_gpi_unmap(gi2c, &msgs[i], tx_buf, tx_addr, rx_buf, rx_addr);
+
 	return ret;
 }