1 files changed, 459 insertions, 14 deletions

diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
index f9009d6..30f3a2b 100644
--- a/drivers/i2c/busses/i2c-qup.c
+++ b/drivers/i2c/busses/i2c-qup.c
@@ -14,8 +14,12 @@
  *
  */
 
+#include <linux/atomic.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dmapool.h>
+#include <linux/dma-mapping.h>
 #include <linux/err.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
@@ -24,6 +28,7 @@
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/scatterlist.h>
 
 /* QUP Registers */
 #define QUP_CONFIG		0x000
@@ -33,6 +38,7 @@
 #define QUP_OPERATIONAL		0x018
 #define QUP_ERROR_FLAGS		0x01c
 #define QUP_ERROR_FLAGS_EN	0x020
+#define QUP_OPERATIONAL_MASK	0x028
 #define QUP_HW_VERSION		0x030
 #define QUP_MX_OUTPUT_CNT	0x100
 #define QUP_OUT_FIFO_BASE	0x110
@@ -52,6 +58,7 @@
 
 #define QUP_STATE_VALID		BIT(2)
 #define QUP_I2C_MAST_GEN	BIT(4)
+#define QUP_I2C_FLUSH		BIT(6)
 
 #define QUP_OPERATIONAL_RESET	0x000ff0
 #define QUP_I2C_STATUS_RESET	0xfffffc
@@ -77,7 +84,10 @@
 
 /* Packing/Unpacking words in FIFOs, and IO modes */
 #define QUP_OUTPUT_BLK_MODE	(1 << 10)
+#define QUP_OUTPUT_BAM_MODE	(3 << 10)
 #define QUP_INPUT_BLK_MODE	(1 << 12)
+#define QUP_INPUT_BAM_MODE	(3 << 12)
+#define QUP_BAM_MODE		(QUP_OUTPUT_BAM_MODE | QUP_INPUT_BAM_MODE)
 #define QUP_UNPACK_EN		BIT(14)
 #define QUP_PACK_EN		BIT(15)
 
@@ -94,6 +104,8 @@
 #define QUP_TAG_DATA		(2 << 8)
 #define QUP_TAG_STOP		(3 << 8)
 #define QUP_TAG_REC		(4 << 8)
+#define QUP_BAM_INPUT_EOT		0x93
+#define QUP_BAM_FLUSH_STOP		0x96
 
 /* QUP v2 tags */
 #define QUP_TAG_V2_START               0x81
@@ -114,6 +126,12 @@
 #define ONE_BYTE			0x1
 #define QUP_I2C_MX_CONFIG_DURING_RUN   BIT(31)
 
+#define MX_TX_RX_LEN			SZ_64K
+#define MX_BLOCKS			(MX_TX_RX_LEN / QUP_READ_LIMIT)
+
+/* Max timeout in ms for 32k bytes */
+#define TOUT_MAX			300
+
 struct qup_i2c_block {
 	int	count;
 	int	pos;
@@ -123,6 +141,17 @@ struct qup_i2c_block {
 	u8	tags[6];
 };
 
+struct qup_i2c_tag {
+	u8 *start;
+	dma_addr_t addr;
+};
+
+struct qup_i2c_bam {
+	struct	qup_i2c_tag tag;
+	struct	dma_chan *dma;
+	struct	scatterlist *sg;
+};
+
 struct qup_i2c_dev {
 	struct device		*dev;
 	void __iomem		*base;
@@ -154,6 +183,13 @@ struct qup_i2c_dev {
 	/* To configure when bus is in run state */
 	int			config_run;
 
+	/* dma parameters */
+	bool			is_dma;
+	struct			dma_pool *dpool;
+	struct			qup_i2c_tag start_tag;
+	struct			qup_i2c_bam brx;
+	struct			qup_i2c_bam btx;
+
 	struct completion	xfer;
 };
 
@@ -230,6 +266,14 @@ static int qup_i2c_poll_state(struct qup_i2c_dev *qup, u32 req_state)
 	return qup_i2c_poll_state_mask(qup, req_state, QUP_STATE_MASK);
 }
 
+static void qup_i2c_flush(struct qup_i2c_dev *qup)
+{
+	u32 val = readl(qup->base + QUP_STATE);
+
+	val |= QUP_I2C_FLUSH;
+	writel(val, qup->base + QUP_STATE);
+}
+
 static int qup_i2c_poll_state_valid(struct qup_i2c_dev *qup)
 {
 	return qup_i2c_poll_state_mask(qup, 0, 0);
@@ -437,12 +481,14 @@ static int qup_i2c_get_data_len(struct qup_i2c_dev *qup)
 }
 
 static int qup_i2c_set_tags(u8 *tags, struct qup_i2c_dev *qup,
-			    struct i2c_msg *msg)
+			    struct i2c_msg *msg,  int is_dma)
 {
 	u16 addr = (msg->addr << 1) | ((msg->flags & I2C_M_RD) == I2C_M_RD);
 	int len = 0;
 	int data_len;
 
+	int last = (qup->blk.pos == (qup->blk.count - 1)) && (qup->is_last);
+
 	if (qup->blk.pos == 0) {
 		tags[len++] = QUP_TAG_V2_START;
 		tags[len++] = addr & 0xff;
@@ -452,7 +498,7 @@ static int qup_i2c_set_tags(u8 *tags, struct qup_i2c_dev *qup,
 	}
 
 	/* Send _STOP commands for the last block */
-	if ((qup->blk.pos == (qup->blk.count - 1)) && qup->is_last) {
+	if (last) {
 		if (msg->flags & I2C_M_RD)
 			tags[len++] = QUP_TAG_V2_DATARD_STOP;
 		else
@@ -472,6 +518,11 @@ static int qup_i2c_set_tags(u8 *tags, struct qup_i2c_dev *qup,
 	else
 		tags[len++] = data_len;
 
+	if ((msg->flags & I2C_M_RD) && last && is_dma) {
+		tags[len++] = QUP_BAM_INPUT_EOT;
+		tags[len++] = QUP_BAM_FLUSH_STOP;
+	}
+
 	return len;
 }
 
@@ -480,7 +531,7 @@ static int qup_i2c_issue_xfer_v2(struct qup_i2c_dev *qup, struct i2c_msg *msg)
 	int data_len = 0, tag_len, index;
 	int ret;
 
-	tag_len = qup_i2c_set_tags(qup->blk.tags, qup, msg);
+	tag_len = qup_i2c_set_tags(qup->blk.tags, qup, msg, 0);
 	index = msg->len - qup->blk.data_len;
 
 	/* only tags are written for read */
@@ -494,6 +545,306 @@ static int qup_i2c_issue_xfer_v2(struct qup_i2c_dev *qup, struct i2c_msg *msg)
 	return ret;
 }
 
+static void qup_i2c_bam_cb(void *data)
+{
+	struct qup_i2c_dev *qup = data;
+
+	complete(&qup->xfer);
+}
+
+static int qup_sg_set_buf(struct scatterlist *sg, void *buf,
+			  struct qup_i2c_tag *tg, unsigned int buflen,
+			  struct qup_i2c_dev *qup, int map, int dir)
+{
+	int ret;
+
+	sg_set_buf(sg, buf, buflen);
+	ret = dma_map_sg(qup->dev, sg, 1, dir);
+	if (!ret)
+		return -EINVAL;
+
+	if (!map)
+		sg_dma_address(sg) = tg->addr + ((u8 *)buf - tg->start);
+
+	return 0;
+}
+
+static void qup_i2c_rel_dma(struct qup_i2c_dev *qup)
+{
+	if (qup->btx.dma)
+		dma_release_channel(qup->btx.dma);
+	if (qup->brx.dma)
+		dma_release_channel(qup->brx.dma);
+	qup->btx.dma = NULL;
+	qup->brx.dma = NULL;
+}
+
+static int qup_i2c_req_dma(struct qup_i2c_dev *qup)
+{
+	int err;
+
+	if (!qup->btx.dma) {
+		qup->btx.dma = dma_request_slave_channel_reason(qup->dev, "tx");
+		if (IS_ERR(qup->btx.dma)) {
+			err = PTR_ERR(qup->btx.dma);
+			qup->btx.dma = NULL;
+			dev_err(qup->dev, "\n tx channel not available");
+			return err;
+		}
+	}
+
+	if (!qup->brx.dma) {
+		qup->brx.dma = dma_request_slave_channel_reason(qup->dev, "rx");
+		if (IS_ERR(qup->brx.dma)) {
+			dev_err(qup->dev, "\n rx channel not available");
+			err = PTR_ERR(qup->brx.dma);
+			qup->brx.dma = NULL;
+			qup_i2c_rel_dma(qup);
+			return err;
+		}
+	}
+	return 0;
+}
+
+static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg,
+			       int num)
+{
+	struct dma_async_tx_descriptor *txd, *rxd = NULL;
+	int ret = 0, idx = 0, limit = QUP_READ_LIMIT;
+	dma_cookie_t cookie_rx, cookie_tx;
+	u32 rx_nents = 0, tx_nents = 0, len, blocks, rem;
+	u32 i, tlen, tx_len, tx_buf = 0, rx_buf = 0, off = 0;
+	u8 *tags;
+
+	while (idx < num) {
+		blocks = (msg->len + limit) / limit;
+		rem = msg->len % limit;
+		tx_len = 0, len = 0, i = 0;
+
+		qup->is_last = (idx == (num - 1));
+
+		qup_i2c_set_blk_data(qup, msg);
+
+		if (msg->flags & I2C_M_RD) {
+			rx_nents += (blocks * 2) + 1;
+			tx_nents += 1;
+
+			while (qup->blk.pos < blocks) {
+				/* length set to '0' implies 256 bytes */
+				tlen = (i == (blocks - 1)) ? rem : 0;
+				tags = &qup->start_tag.start[off + len];
+				len += qup_i2c_set_tags(tags, qup, msg, 1);
+
+				/* scratch buf to read the start and len tags */
+				ret = qup_sg_set_buf(&qup->brx.sg[rx_buf++],
+						     &qup->brx.tag.start[0],
+						     &qup->brx.tag,
+						     2, qup, 0, 0);
+
+				if (ret)
+					return ret;
+
+				ret = qup_sg_set_buf(&qup->brx.sg[rx_buf++],
+						     &msg->buf[limit * i],
+						     NULL, tlen, qup,
+						     1, DMA_FROM_DEVICE);
+				if (ret)
+					return ret;
+
+				i++;
+				qup->blk.pos = i;
+			}
+			ret = qup_sg_set_buf(&qup->btx.sg[tx_buf++],
+					     &qup->start_tag.start[off],
+					     &qup->start_tag, len, qup, 0, 0);
+			if (ret)
+				return ret;
+
+			off += len;
+			/* scratch buf to read the BAM EOT and FLUSH tags */
+			ret = qup_sg_set_buf(&qup->brx.sg[rx_buf++],
+					     &qup->brx.tag.start[0],
+					     &qup->brx.tag, 2,
+					     qup, 0, 0);
+			if (ret)
+				return ret;
+		} else {
+			tx_nents += (blocks * 2);
+
+			while (qup->blk.pos < blocks) {
+				tlen = (i == (blocks - 1)) ? rem : 0;
+				tags = &qup->start_tag.start[off + tx_len];
+				len = qup_i2c_set_tags(tags, qup, msg, 1);
+
+				ret = qup_sg_set_buf(&qup->btx.sg[tx_buf++],
+						     tags,
+						     &qup->start_tag, len,
+						     qup, 0, 0);
+				if (ret)
+					return ret;
+
+				tx_len += len;
+				ret = qup_sg_set_buf(&qup->btx.sg[tx_buf++],
+						     &msg->buf[limit * i],
+						     NULL, tlen, qup, 1,
+						     DMA_TO_DEVICE);
+				if (ret)
+					return ret;
+				i++;
+				qup->blk.pos = i;
+			}
+			off += tx_len;
+
+			if (idx == (num - 1)) {
+				len = 1;
+				if (rx_nents) {
+					qup->btx.tag.start[0] =
+							QUP_BAM_INPUT_EOT;
+					len++;
+				}
+				qup->btx.tag.start[len - 1] =
+							QUP_BAM_FLUSH_STOP;
+				ret = qup_sg_set_buf(&qup->btx.sg[tx_buf++],
+						     &qup->btx.tag.start[0],
+						     &qup->btx.tag, len,
+						     qup, 0, 0);
+				if (ret)
+					return ret;
+				tx_nents += 1;
+			}
+		}
+		idx++;
+		msg++;
+	}
+
+	txd = dmaengine_prep_slave_sg(qup->btx.dma, qup->btx.sg, tx_nents,
+				      DMA_MEM_TO_DEV,
+				      DMA_PREP_INTERRUPT | DMA_PREP_FENCE);
+	if (!txd) {
+		dev_err(qup->dev, "failed to get tx desc\n");
+		ret = -EINVAL;
+		goto desc_err;
+	}
+
+	if (!rx_nents) {
+		txd->callback = qup_i2c_bam_cb;
+		txd->callback_param = qup;
+	}
+
+	cookie_tx = dmaengine_submit(txd);
+	if (dma_submit_error(cookie_tx)) {
+		ret = -EINVAL;
+		goto desc_err;
+	}
+
+	dma_async_issue_pending(qup->btx.dma);
+
+	if (rx_nents) {
+		rxd = dmaengine_prep_slave_sg(qup->brx.dma, qup->brx.sg,
+					      rx_nents, DMA_DEV_TO_MEM,
+					      DMA_PREP_INTERRUPT);
+		if (!rxd) {
+			dev_err(qup->dev, "failed to get rx desc\n");
+			ret = -EINVAL;
+
+			/* abort TX descriptors */
+			dmaengine_terminate_all(qup->btx.dma);
+			goto desc_err;
+		}
+
+		rxd->callback = qup_i2c_bam_cb;
+		rxd->callback_param = qup;
+		cookie_rx = dmaengine_submit(rxd);
+		if (dma_submit_error(cookie_rx)) {
+			ret = -EINVAL;
+			goto desc_err;
+		}
+
+		dma_async_issue_pending(qup->brx.dma);
+	}
+
+	if (!wait_for_completion_timeout(&qup->xfer, TOUT_MAX * HZ)) {
+		dev_err(qup->dev, "normal trans timed out\n");
+		ret = -ETIMEDOUT;
+	}
+
+	if (ret || qup->bus_err || qup->qup_err) {
+		if (qup->bus_err & QUP_I2C_NACK_FLAG) {
+			msg--;
+			dev_err(qup->dev, "NACK from %x\n", msg->addr);
+			ret = -EIO;
+
+			if (qup_i2c_change_state(qup, QUP_RUN_STATE)) {
+				dev_err(qup->dev, "change to run state timed out");
+				return ret;
+			}
+
+			if (rx_nents)
+				writel(QUP_BAM_INPUT_EOT,
+				       qup->base + QUP_OUT_FIFO_BASE);
+
+			writel(QUP_BAM_FLUSH_STOP,
+			       qup->base + QUP_OUT_FIFO_BASE);
+
+			qup_i2c_flush(qup);
+
+			/* wait for remaining interrupts to occur */
+			if (!wait_for_completion_timeout(&qup->xfer, HZ))
+				dev_err(qup->dev, "flush timed out\n");
+
+			qup_i2c_rel_dma(qup);
+		}
+	}
+
+	dma_unmap_sg(qup->dev, qup->btx.sg, tx_nents, DMA_TO_DEVICE);
+
+	if (rx_nents)
+		dma_unmap_sg(qup->dev, qup->brx.sg, rx_nents,
+			     DMA_FROM_DEVICE);
+desc_err:
+	return ret;
+}
+
+static int qup_i2c_bam_xfer(struct i2c_adapter *adap, struct i2c_msg *msg,
+			    int num)
+{
+	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
+	int ret = 0;
+
+	enable_irq(qup->irq);
+	ret = qup_i2c_req_dma(qup);
+
+	if (ret)
+		goto out;
+
+	qup->bus_err = 0;
+	qup->qup_err = 0;
+
+	writel(0, qup->base + QUP_MX_INPUT_CNT);
+	writel(0, qup->base + QUP_MX_OUTPUT_CNT);
+
+	/* set BAM mode */
+	writel(QUP_REPACK_EN | QUP_BAM_MODE, qup->base + QUP_IO_MODE);
+
+	/* mask fifo irqs */
+	writel((0x3 << 8), qup->base + QUP_OPERATIONAL_MASK);
+
+	/* set RUN STATE */
+	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
+	if (ret)
+		goto out;
+
+	writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
+
+	qup->msg = msg;
+	ret = qup_i2c_bam_do_xfer(qup, qup->msg, num);
+out:
+	disable_irq(qup->irq);
+
+	qup->msg = NULL;
+	return ret;
+}
+
 static int qup_i2c_wait_for_complete(struct qup_i2c_dev *qup,
 				     struct i2c_msg *msg)
 {
@@ -850,7 +1201,7 @@ static int qup_i2c_xfer_v2(struct i2c_adapter *adap,
 			   int num)
 {
 	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
-	int ret, idx;
+	int ret, len, idx = 0, use_dma = 0;
 
 	ret = pm_runtime_get_sync(qup->dev);
 	if (ret < 0)
@@ -865,7 +1216,27 @@ static int qup_i2c_xfer_v2(struct i2c_adapter *adap,
 	writel(I2C_MINI_CORE | I2C_N_VAL_V2, qup->base + QUP_CONFIG);
 	writel(QUP_V2_TAGS_EN, qup->base + QUP_I2C_MASTER_GEN);
 
-	for (idx = 0; idx < num; idx++) {
+	if ((qup->is_dma)) {
+		/* All i2c_msgs should be transferred using either dma or cpu */
+		for (idx = 0; idx < num; idx++) {
+			if (msgs[idx].len == 0) {
+				ret = -EINVAL;
+				goto out;
+			}
+
+			len = (msgs[idx].len > qup->out_fifo_sz) ||
+			      (msgs[idx].len > qup->in_fifo_sz);
+
+			if ((!is_vmalloc_addr(msgs[idx].buf)) && len) {
+				use_dma = 1;
+			 } else {
+				use_dma = 0;
+				break;
+			}
+		}
+	}
+
+	do {
 		if (msgs[idx].len == 0) {
 			ret = -EINVAL;
 			goto out;
@@ -884,14 +1255,15 @@ static int qup_i2c_xfer_v2(struct i2c_adapter *adap,
 
 		reinit_completion(&qup->xfer);
 
-		if (msgs[idx].flags & I2C_M_RD)
-			ret = qup_i2c_read_one_v2(qup, &msgs[idx]);
-		else
-			ret = qup_i2c_write_one_v2(qup, &msgs[idx]);
-
-		if (ret)
-			break;
-	}
+		if (use_dma) {
+			ret = qup_i2c_bam_xfer(adap, &msgs[idx], num);
+		} else {
+			if (msgs[idx].flags & I2C_M_RD)
+				ret = qup_i2c_read_one_v2(qup, &msgs[idx]);
+			else
+				ret = qup_i2c_write_one_v2(qup, &msgs[idx]);
+		}
+	} while ((idx++ < (num - 1)) && !use_dma && !ret);
 
 	if (!ret)
 		ret = qup_i2c_change_state(qup, QUP_RESET_STATE);
@@ -958,6 +1330,7 @@ static int qup_i2c_probe(struct platform_device *pdev)
 	int ret, fs_div, hs_div;
 	int src_clk_freq;
 	u32 clk_freq = 100000;
+	int blocks;
 
 	qup = devm_kzalloc(&pdev->dev, sizeof(*qup), GFP_KERNEL);
 	if (!qup)
@@ -974,8 +1347,63 @@ static int qup_i2c_probe(struct platform_device *pdev)
 		qup->adap.quirks = &qup_i2c_quirks;
 	} else {
 		qup->adap.algo = &qup_i2c_algo_v2;
+		ret = qup_i2c_req_dma(qup);
+
+		if (ret == -EPROBE_DEFER)
+			goto fail_dma;
+		else if (ret != 0)
+			goto nodma;
+
+		blocks = (MX_BLOCKS << 1) + 1;
+		qup->btx.sg = devm_kzalloc(&pdev->dev,
+					   sizeof(*qup->btx.sg) * blocks,
+					   GFP_KERNEL);
+		if (!qup->btx.sg) {
+			ret = -ENOMEM;
+			goto fail_dma;
+		}
+		sg_init_table(qup->btx.sg, blocks);
+
+		qup->brx.sg = devm_kzalloc(&pdev->dev,
+					   sizeof(*qup->brx.sg) * blocks,
+					   GFP_KERNEL);
+		if (!qup->brx.sg) {
+			ret = -ENOMEM;
+			goto fail_dma;
+		}
+		sg_init_table(qup->brx.sg, blocks);
+
+		/* 2 tag bytes for each block + 5 for start, stop tags */
+		size = blocks * 2 + 5;
+		qup->dpool = dma_pool_create("qup_i2c-dma-pool", &pdev->dev,
+					     size, 4, 0);
+
+		qup->start_tag.start = dma_pool_alloc(qup->dpool, GFP_KERNEL,
+						      &qup->start_tag.addr);
+		if (!qup->start_tag.start) {
+			ret = -ENOMEM;
+			goto fail_dma;
+		}
+
+		qup->brx.tag.start = dma_pool_alloc(qup->dpool,
+						    GFP_KERNEL,
+						    &qup->brx.tag.addr);
+		if (!qup->brx.tag.start) {
+			ret = -ENOMEM;
+			goto fail_dma;
+		}
+
+		qup->btx.tag.start = dma_pool_alloc(qup->dpool,
+						    GFP_KERNEL,
+						    &qup->btx.tag.addr);
+		if (!qup->btx.tag.start) {
+			ret = -ENOMEM;
+			goto fail_dma;
+		}
+		qup->is_dma = true;
 	}
 
+nodma:
 	/* We support frequencies up to FAST Mode (400KHz) */
 	if (!clk_freq || clk_freq > 400000) {
 		dev_err(qup->dev, "clock frequency not supported %d\n",
@@ -1073,7 +1501,7 @@ static int qup_i2c_probe(struct platform_device *pdev)
 	i2c_set_adapdata(&qup->adap, qup);
 	qup->adap.dev.parent = qup->dev;
 	qup->adap.dev.of_node = pdev->dev.of_node;
-	qup->is_last = 1;
+	qup->is_last = true;
 
 	strlcpy(qup->adap.name, "QUP I2C adapter", sizeof(qup->adap.name));
 
@@ -1093,6 +1521,11 @@ fail_runtime:
 	pm_runtime_set_suspended(qup->dev);
 fail:
 	qup_i2c_disable_clocks(qup);
+fail_dma:
+	if (qup->btx.dma)
+		dma_release_channel(qup->btx.dma);
+	if (qup->brx.dma)
+		dma_release_channel(qup->brx.dma);
 	return ret;
 }
 
@@ -1100,6 +1533,18 @@ static int qup_i2c_remove(struct platform_device *pdev)
 {
 	struct qup_i2c_dev *qup = platform_get_drvdata(pdev);
 
+	if (qup->is_dma) {
+		dma_pool_free(qup->dpool, qup->start_tag.start,
+			      qup->start_tag.addr);
+		dma_pool_free(qup->dpool, qup->brx.tag.start,
+			      qup->brx.tag.addr);
+		dma_pool_free(qup->dpool, qup->btx.tag.start,
+			      qup->btx.tag.addr);
+		dma_pool_destroy(qup->dpool);
+		dma_release_channel(qup->btx.dma);
+		dma_release_channel(qup->brx.dma);
+	}
+
 	disable_irq(qup->irq);
 	qup_i2c_disable_clocks(qup);
 	i2c_del_adapter(&qup->adap);