Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1307113 > unrolled thread

[PATCH V6 0/6] i2c: qup: Add support for v2 tags and bam dma

Back to article view | Back to linux.kernel

Contents

  [PATCH V6 0/6] i2c: qup: Add support for v2 tags and bam dma Sricharan R <sricharan@codeaurora.org> - 2016-01-12 09:50 +0100
    [PATCH V6 2/6] i2c: qup: Add V2 tags support Sricharan R <sricharan@codeaurora.org> - 2016-01-12 09:50 +0100
    [PATCH V6 1/6] i2c: qup: Change qup_wait_writeready function to use for all timeouts Sricharan R <sricharan@codeaurora.org> - 2016-01-12 09:50 +0100
    Re: [PATCH V6 0/6] i2c: qup: Add support for v2 tags and bam dma Archit Taneja <architt@codeaurora.org> - 2016-01-12 11:30 +0100

#1307113 — [PATCH V6 0/6] i2c: qup: Add support for v2 tags and bam dma

i2c: qup: Add support for v2 tags and bam dma

QUP from version 2.1.1 onwards, supports a new format of i2c command tags.
Tag codes instructs the controller to perform a operation like read/write.
This new tagging version supports and is required for adding bam dma
capabilities. V2 tags supports transfer of more than 256 bytes in a single i2c
transaction. Also adding bam dma support facilitates transferring each i2c_msg
in i2c_msgs without a 'stop' bit in between which is required for some of
the clients.

Tested this series on apq8074 dragon board eeprom client on i2c bus1

[V6] Added review tags and fixed a checkpatch warning in patch 4/6.

[V5] Addressed few more comments from Ivan T. Ivanov.
     Squashed patch 2 and 3 as no point in having only few lines of
     common code between v1 and v2 tags for increased complexity.
     Couple of non functional review comments fixes in patch 3, 4.
     Added a change in patch 4 to have proper transfer completion in
     a corner case. patch 5, 6 unchanged.

[V4] Added a patch to factor out some common code.
     Removed support for freq > 400KHZ as per comments.
     Addressed comments from Ivan T. Ivanov to keep the code for
     V2 support in a separate path.
     Changed the authorship of V2 tags support patch.

[V3] Added support to coalesce each i2c_msg in i2c_msgs for fifo and
     block mode in Patch 2. Also addressed further code comments.

     http://comments.gmane.org/gmane.linux.drivers.i2c/22497

[V2] Addressed comments from Ivan T. Ivanov, Andy Gross [v1] Initial Version

Sricharan R (6):
  i2c: qup: Change qup_wait_writeready function to use for all timeouts
  i2c: qup: Add V2 tags support
  i2c: qup: Transfer each i2c_msg in i2c_msgs without a stop bit
  i2c: qup: Add bam dma capabilities
  dts: msm8974: Add blsp2_bam dma node
  dts: msm8974: Add dma channels for blsp2_i2c1 node

 arch/arm/boot/dts/qcom-msm8974.dtsi |  14 +-
 drivers/i2c/busses/i2c-qup.c        | 922 ++++++++++++++++++++++++++++++++++--
 2 files changed, 887 insertions(+), 49 deletions(-)

-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[toc] | [next] | [standalone]

#1307115 — [PATCH V6 2/6] i2c: qup: Add V2 tags support

QUP from version 2.1.1 onwards, supports a new format of
i2c command tags. Tag codes instructs the controller to
perform a operation like read/write. This new tagging version
supports bam dma and transfers of more than 256 bytes without 'stop'
in between. Adding the support for the same.

For each block a data_write/read tag and data_len tag is added to
the output fifo. For the final block of data write_stop/read_stop
tag is used.

Signed-off-by: Andy Gross <agross@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
---
 drivers/i2c/busses/i2c-qup.c | 415 ++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 386 insertions(+), 29 deletions(-)

diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
index 81ed120..715d4d7 100644
--- a/drivers/i2c/busses/i2c-qup.c
+++ b/drivers/i2c/busses/i2c-qup.c
@@ -42,6 +42,7 @@
 #define QUP_IN_FIFO_BASE	0x218
 #define QUP_I2C_CLK_CTL		0x400
 #define QUP_I2C_STATUS		0x404
+#define QUP_I2C_MASTER_GEN	0x408
 
 /* QUP States and reset values */
 #define QUP_RESET_STATE		0
@@ -69,6 +70,8 @@
 #define QUP_CLOCK_AUTO_GATE	BIT(13)
 #define I2C_MINI_CORE		(2 << 8)
 #define I2C_N_VAL		15
+#define I2C_N_VAL_V2		7
+
 /* Most significant word offset in FIFO port */
 #define QUP_MSW_SHIFT		(I2C_N_VAL + 1)
 
@@ -79,6 +82,7 @@
 #define QUP_PACK_EN		BIT(15)
 
 #define QUP_REPACK_EN		(QUP_UNPACK_EN | QUP_PACK_EN)
+#define QUP_V2_TAGS_EN		1
 
 #define QUP_OUTPUT_BLOCK_SIZE(x)(((x) >> 0) & 0x03)
 #define QUP_OUTPUT_FIFO_SIZE(x)	(((x) >> 2) & 0x07)
@@ -91,6 +95,13 @@
 #define QUP_TAG_STOP		(3 << 8)
 #define QUP_TAG_REC		(4 << 8)
 
+/* QUP v2 tags */
+#define QUP_TAG_V2_START               0x81
+#define QUP_TAG_V2_DATAWR              0x82
+#define QUP_TAG_V2_DATAWR_STOP         0x83
+#define QUP_TAG_V2_DATARD              0x85
+#define QUP_TAG_V2_DATARD_STOP         0x87
+
 /* Status, Error flags */
 #define I2C_STATUS_WR_BUFFER_FULL	BIT(0)
 #define I2C_STATUS_BUS_ACTIVE		BIT(8)
@@ -102,6 +113,15 @@
 #define RESET_BIT			0x0
 #define ONE_BYTE			0x1
 
+struct qup_i2c_block {
+	int	count;
+	int	pos;
+	int	tx_tag_len;
+	int	rx_tag_len;
+	int	data_len;
+	u8	tags[6];
+};
+
 struct qup_i2c_dev {
 	struct device		*dev;
 	void __iomem		*base;
@@ -117,6 +137,7 @@ struct qup_i2c_dev {
 	int			in_blk_sz;
 
 	unsigned long		one_byte_t;
+	struct qup_i2c_block	blk;
 
 	struct i2c_msg		*msg;
 	/* Current posion in user message buffer */
@@ -263,6 +284,24 @@ static int qup_i2c_wait_ready(struct qup_i2c_dev *qup, int op, bool val,
 	}
 }
 
+static void qup_i2c_set_write_mode_v2(struct qup_i2c_dev *qup,
+				      struct i2c_msg *msg)
+{
+	/* Number of entries to shift out, including the tags */
+	int total = msg->len + qup->blk.tx_tag_len;
+
+	if (total < qup->out_fifo_sz) {
+		/* FIFO mode */
+		writel(QUP_REPACK_EN, qup->base + QUP_IO_MODE);
+		writel(total, qup->base + QUP_MX_WRITE_CNT);
+	} else {
+		/* BLOCK mode (transfer data on chunks) */
+		writel(QUP_OUTPUT_BLK_MODE | QUP_REPACK_EN,
+		       qup->base + QUP_IO_MODE);
+		writel(total, qup->base + QUP_MX_OUTPUT_CNT);
+	}
+}
+
 static void qup_i2c_set_write_mode(struct qup_i2c_dev *qup, struct i2c_msg *msg)
 {
 	/* Number of entries to shift out, including the start */
@@ -324,9 +363,189 @@ static int qup_i2c_issue_write(struct qup_i2c_dev *qup, struct i2c_msg *msg)
 	return ret;
 }
 
-static int qup_i2c_write_one(struct qup_i2c_dev *qup, struct i2c_msg *msg)
+static void qup_i2c_set_blk_data(struct qup_i2c_dev *qup,
+				 struct i2c_msg *msg)
+{
+	memset(&qup->blk, 0, sizeof(qup->blk));
+
+	qup->blk.data_len = msg->len;
+	qup->blk.count = (msg->len + QUP_READ_LIMIT - 1) / QUP_READ_LIMIT;
+
+	/* 4 bytes for first block and 2 writes for rest */
+	qup->blk.tx_tag_len = 4 + (qup->blk.count - 1) * 2;
+
+	/* There are 2 tag bytes that are read in to fifo for every block */
+	if (msg->flags & I2C_M_RD)
+		qup->blk.rx_tag_len = qup->blk.count * 2;
+}
+
+static int qup_i2c_send_data(struct qup_i2c_dev *qup, int tlen, u8 *tbuf,
+			     int dlen, u8 *dbuf)
+{
+	u32 val = 0, idx = 0, pos = 0, i = 0, t;
+	int  len = tlen + dlen;
+	u8 *buf = tbuf;
+	int ret = 0;
+
+	while (len > 0) {
+		ret = qup_i2c_wait_ready(qup, QUP_OUT_FULL,
+					 RESET_BIT, 4 * ONE_BYTE);
+		if (ret) {
+			dev_err(qup->dev, "timeout for fifo out full");
+			return ret;
+		}
+
+		t = (len >= 4) ? 4 : len;
+
+		while (idx < t) {
+			if (!i && (pos >= tlen)) {
+				buf = dbuf;
+				pos = 0;
+				i = 1;
+			}
+			val |= buf[pos++] << (idx++ * 8);
+		}
+
+		writel(val, qup->base + QUP_OUT_FIFO_BASE);
+		idx  = 0;
+		val = 0;
+		len -= 4;
+	}
+
+	return ret;
+}
+
+static int qup_i2c_get_data_len(struct qup_i2c_dev *qup)
+{
+	int data_len;
+
+	if (qup->blk.data_len > QUP_READ_LIMIT)
+		data_len = QUP_READ_LIMIT;
+	else
+		data_len = qup->blk.data_len;
+
+	return data_len;
+}
+
+static int qup_i2c_set_tags(u8 *tags, struct qup_i2c_dev *qup,
+			    struct i2c_msg *msg)
+{
+	u16 addr = (msg->addr << 1) | ((msg->flags & I2C_M_RD) == I2C_M_RD);
+	int len = 0;
+	int data_len;
+
+	if (qup->blk.pos == 0) {
+		tags[len++] = QUP_TAG_V2_START;
+		tags[len++] = addr & 0xff;
+
+		if (msg->flags & I2C_M_TEN)
+			tags[len++] = addr >> 8;
+	}
+
+	/* Send _STOP commands for the last block */
+	if (qup->blk.pos == (qup->blk.count - 1)) {
+		if (msg->flags & I2C_M_RD)
+			tags[len++] = QUP_TAG_V2_DATARD_STOP;
+		else
+			tags[len++] = QUP_TAG_V2_DATAWR_STOP;
+	} else {
+		if (msg->flags & I2C_M_RD)
+			tags[len++] = QUP_TAG_V2_DATARD;
+		else
+			tags[len++] = QUP_TAG_V2_DATAWR;
+	}
+
+	data_len = qup_i2c_get_data_len(qup);
+
+	/* 0 implies 256 bytes */
+	if (data_len == QUP_READ_LIMIT)
+		tags[len++] = 0;
+	else
+		tags[len++] = data_len;
+
+	return len;
+}
+
+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);
+	index = msg->len - qup->blk.data_len;
+
+	/* only tags are written for read */
+	if (!(msg->flags & I2C_M_RD))
+		data_len = qup_i2c_get_data_len(qup);
+
+	ret = qup_i2c_send_data(qup, tag_len, qup->blk.tags,
+				data_len, &msg->buf[index]);
+	qup->blk.data_len -= data_len;
+
+	return ret;
+}
+
+static int qup_i2c_wait_for_complete(struct qup_i2c_dev *qup,
+				     struct i2c_msg *msg)
 {
 	unsigned long left;
+	int ret = 0;
+
+	left = wait_for_completion_timeout(&qup->xfer, HZ);
+	if (!left) {
+		writel(1, qup->base + QUP_SW_RESET);
+		ret = -ETIMEDOUT;
+	}
+
+	if (qup->bus_err || qup->qup_err) {
+		if (qup->bus_err & QUP_I2C_NACK_FLAG) {
+			dev_err(qup->dev, "NACK from %x\n", msg->addr);
+			ret = -EIO;
+		}
+	}
+
+	return ret;
+}
+
+static int qup_i2c_write_one_v2(struct qup_i2c_dev *qup, struct i2c_msg *msg)
+{
+	int ret = 0;
+
+	qup->msg = msg;
+	qup->pos = 0;
+	enable_irq(qup->irq);
+	qup_i2c_set_blk_data(qup, msg);
+	qup_i2c_set_write_mode_v2(qup, msg);
+
+	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
+	if (ret)
+		goto err;
+
+	writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
+
+	do {
+		ret = qup_i2c_issue_xfer_v2(qup, msg);
+		if (ret)
+			goto err;
+
+		ret = qup_i2c_wait_for_complete(qup, msg);
+		if (ret)
+			goto err;
+
+		qup->blk.pos++;
+	} while (qup->blk.pos < qup->blk.count);
+
+	ret = qup_i2c_wait_ready(qup, QUP_OUT_NOT_EMPTY, RESET_BIT, ONE_BYTE);
+
+err:
+	disable_irq(qup->irq);
+	qup->msg = NULL;
+
+	return ret;
+}
+
+static int qup_i2c_write_one(struct qup_i2c_dev *qup, struct i2c_msg *msg)
+{
 	int ret;
 
 	qup->msg = msg;
@@ -355,19 +574,9 @@ static int qup_i2c_write_one(struct qup_i2c_dev *qup, struct i2c_msg *msg)
 		if (ret)
 			goto err;
 
-		left = wait_for_completion_timeout(&qup->xfer, HZ);
-		if (!left) {
-			writel(1, qup->base + QUP_SW_RESET);
-			ret = -ETIMEDOUT;
-			goto err;
-		}
-
-		if (qup->bus_err || qup->qup_err) {
-			if (qup->bus_err & QUP_I2C_NACK_FLAG)
-				dev_err(qup->dev, "NACK from %x\n", msg->addr);
-			ret = -EIO;
+		ret = qup_i2c_wait_for_complete(qup, msg);
+		if (ret)
 			goto err;
-		}
 	} while (qup->pos < msg->len);
 
 	/* Wait for the outstanding data in the fifo to drain */
@@ -394,6 +603,26 @@ static void qup_i2c_set_read_mode(struct qup_i2c_dev *qup, int len)
 	}
 }
 
+static void qup_i2c_set_read_mode_v2(struct qup_i2c_dev *qup, int len)
+{
+	int tx_len = qup->blk.tx_tag_len;
+
+	len += qup->blk.rx_tag_len;
+
+	if (len < qup->in_fifo_sz) {
+		/* FIFO mode */
+		writel(QUP_REPACK_EN, qup->base + QUP_IO_MODE);
+		writel(len, qup->base + QUP_MX_READ_CNT);
+		writel(tx_len, qup->base + QUP_MX_WRITE_CNT);
+	} else {
+		/* BLOCK mode (transfer data on chunks) */
+		writel(QUP_INPUT_BLK_MODE | QUP_REPACK_EN,
+		       qup->base + QUP_IO_MODE);
+		writel(len, qup->base + QUP_MX_INPUT_CNT);
+		writel(tx_len, qup->base + QUP_MX_OUTPUT_CNT);
+	}
+}
+
 static void qup_i2c_issue_read(struct qup_i2c_dev *qup, struct i2c_msg *msg)
 {
 	u32 addr, len, val;
@@ -434,16 +663,90 @@ static int qup_i2c_read_fifo(struct qup_i2c_dev *qup, struct i2c_msg *msg)
 	return ret;
 }
 
+static int qup_i2c_read_fifo_v2(struct qup_i2c_dev *qup,
+				struct i2c_msg *msg)
+{
+	u32 val;
+	int idx, pos = 0, ret = 0, total;
+
+	total = qup_i2c_get_data_len(qup);
+
+	/* 2 extra bytes for read tags */
+	while (pos < (total + 2)) {
+		/* Check that FIFO have data */
+		ret = qup_i2c_wait_ready(qup, QUP_IN_NOT_EMPTY,
+					 SET_BIT, 4 * ONE_BYTE);
+		if (ret) {
+			dev_err(qup->dev, "timeout for fifo not empty");
+			return ret;
+		}
+		val = readl(qup->base + QUP_IN_FIFO_BASE);
+
+		for (idx = 0; idx < 4; idx++, val >>= 8, pos++) {
+			/* first 2 bytes are tag bytes */
+			if (pos < 2)
+				continue;
+
+			if (pos >= (total + 2))
+				goto out;
+
+			msg->buf[qup->pos++] = val & 0xff;
+		}
+	}
+
+out:
+	qup->blk.data_len -= total;
+
+	return ret;
+}
+
+static int qup_i2c_read_one_v2(struct qup_i2c_dev *qup, struct i2c_msg *msg)
+{
+	int ret = 0;
+
+	qup->msg = msg;
+	qup->pos  = 0;
+	enable_irq(qup->irq);
+	qup_i2c_set_blk_data(qup, msg);
+	qup_i2c_set_read_mode_v2(qup, msg->len);
+
+	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
+	if (ret)
+		goto err;
+
+	writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
+
+	do {
+		ret = qup_i2c_issue_xfer_v2(qup, msg);
+		if (ret)
+			goto err;
+
+		ret = qup_i2c_wait_for_complete(qup, msg);
+		if (ret)
+			goto err;
+
+		ret = qup_i2c_read_fifo_v2(qup, msg);
+		if (ret)
+			goto err;
+
+		qup->blk.pos++;
+	} while (qup->blk.pos < qup->blk.count);
+
+err:
+	disable_irq(qup->irq);
+	qup->msg = NULL;
+
+	return ret;
+}
+
 static int qup_i2c_read_one(struct qup_i2c_dev *qup, struct i2c_msg *msg)
 {
-	unsigned long left;
 	int ret;
 
 	qup->msg = msg;
 	qup->pos  = 0;
 
 	enable_irq(qup->irq);
-
 	qup_i2c_set_read_mode(qup, msg->len);
 
 	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
@@ -463,19 +766,9 @@ static int qup_i2c_read_one(struct qup_i2c_dev *qup, struct i2c_msg *msg)
 		goto err;
 
 	do {
-		left = wait_for_completion_timeout(&qup->xfer, HZ);
-		if (!left) {
-			writel(1, qup->base + QUP_SW_RESET);
-			ret = -ETIMEDOUT;
+		ret = qup_i2c_wait_for_complete(qup, msg);
+		if (ret)
 			goto err;
-		}
-
-		if (qup->bus_err || qup->qup_err) {
-			if (qup->bus_err & QUP_I2C_NACK_FLAG)
-				dev_err(qup->dev, "NACK from %x\n", msg->addr);
-			ret = -EIO;
-			goto err;
-		}
 
 		ret = qup_i2c_read_fifo(qup, msg);
 		if (ret)
@@ -542,6 +835,60 @@ out:
 	return ret;
 }
 
+static int qup_i2c_xfer_v2(struct i2c_adapter *adap,
+			   struct i2c_msg msgs[],
+			   int num)
+{
+	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
+	int ret, idx;
+
+	ret = pm_runtime_get_sync(qup->dev);
+	if (ret < 0)
+		goto out;
+
+	writel(1, qup->base + QUP_SW_RESET);
+	ret = qup_i2c_poll_state(qup, QUP_RESET_STATE);
+	if (ret)
+		goto out;
+
+	/* Configure QUP as I2C mini core */
+	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 (msgs[idx].len == 0) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		if (qup_i2c_poll_state_i2c_master(qup)) {
+			ret = -EIO;
+			goto out;
+		}
+
+		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)
+			ret = qup_i2c_change_state(qup, QUP_RESET_STATE);
+
+		if (ret)
+			break;
+	}
+
+	if (ret == 0)
+		ret = num;
+out:
+	pm_runtime_mark_last_busy(qup->dev);
+	pm_runtime_put_autosuspend(qup->dev);
+
+	return ret;
+}
+
 static u32 qup_i2c_func(struct i2c_adapter *adap)
 {
 	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
@@ -552,6 +899,11 @@ static const struct i2c_algorithm qup_i2c_algo = {
 	.functionality	= qup_i2c_func,
 };
 
+static const struct i2c_algorithm qup_i2c_algo_v2 = {
+	.master_xfer	= qup_i2c_xfer_v2,
+	.functionality	= qup_i2c_func,
+};
+
 /*
  * The QUP block will issue a NACK and STOP on the bus when reaching
  * the end of the read, the length of the read is specified as one byte
@@ -601,6 +953,13 @@ static int qup_i2c_probe(struct platform_device *pdev)
 
 	of_property_read_u32(node, "clock-frequency", &clk_freq);
 
+	if (of_device_is_compatible(pdev->dev.of_node, "qcom,i2c-qup-v1.1.1")) {
+		qup->adap.algo = &qup_i2c_algo;
+		qup->adap.quirks = &qup_i2c_quirks;
+	} else {
+		qup->adap.algo = &qup_i2c_algo_v2;
+	}
+
 	/* We support frequencies up to FAST Mode (400KHz) */
 	if (!clk_freq || clk_freq > 400000) {
 		dev_err(qup->dev, "clock frequency not supported %d\n",
@@ -696,8 +1055,6 @@ static int qup_i2c_probe(struct platform_device *pdev)
 		qup->out_blk_sz, qup->out_fifo_sz);
 
 	i2c_set_adapdata(&qup->adap, qup);
-	qup->adap.algo = &qup_i2c_algo;
-	qup->adap.quirks = &qup_i2c_quirks;
 	qup->adap.dev.parent = qup->dev;
 	qup->adap.dev.of_node = pdev->dev.of_node;
 	strlcpy(qup->adap.name, "QUP I2C adapter", sizeof(qup->adap.name));
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[toc] | [prev] | [next] | [standalone]

#1307117 — [PATCH V6 1/6] i2c: qup: Change qup_wait_writeready function to use for all timeouts

qup_wait_writeready waits only on a output fifo empty event.
Change the same function to accept the event and data length
to wait as parameters. This way the same function can be used for
timeouts in other places as well.

Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Reviewed-by: Andy Gross <andy.gross@linaro.org>
---
 drivers/i2c/busses/i2c-qup.c | 67 +++++++++++++++++++++++++++++++-------------
 1 file changed, 48 insertions(+), 19 deletions(-)

diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
index fdcbdab..81ed120 100644
--- a/drivers/i2c/busses/i2c-qup.c
+++ b/drivers/i2c/busses/i2c-qup.c
@@ -98,6 +98,9 @@
 #define QUP_STATUS_ERROR_FLAGS		0x7c
 
 #define QUP_READ_LIMIT			256
+#define SET_BIT				0x1
+#define RESET_BIT			0x0
+#define ONE_BYTE			0x1
 
 struct qup_i2c_dev {
 	struct device		*dev;
@@ -221,26 +224,42 @@ static int qup_i2c_change_state(struct qup_i2c_dev *qup, u32 state)
 	return 0;
 }
 
-static int qup_i2c_wait_writeready(struct qup_i2c_dev *qup)
+/**
+ * qup_i2c_wait_ready - wait for a give number of bytes in tx/rx path
+ * @qup: The qup_i2c_dev device
+ * @op: The bit/event to wait on
+ * @val: value of the bit to wait on, 0 or 1
+ * @len: The length the bytes to be transferred
+ */
+static int qup_i2c_wait_ready(struct qup_i2c_dev *qup, int op, bool val,
+			      int len)
 {
 	unsigned long timeout;
 	u32 opflags;
 	u32 status;
+	u32 shift = __ffs(op);
 
-	timeout = jiffies + HZ;
+	len *= qup->one_byte_t;
+	/* timeout after a wait of twice the max time */
+	timeout = jiffies + len * 4;
 
 	for (;;) {
 		opflags = readl(qup->base + QUP_OPERATIONAL);
 		status = readl(qup->base + QUP_I2C_STATUS);
 
-		if (!(opflags & QUP_OUT_NOT_EMPTY) &&
-		    !(status & I2C_STATUS_BUS_ACTIVE))
-			return 0;
+		if (((opflags & op) >> shift) == val) {
+			if (op == QUP_OUT_NOT_EMPTY) {
+				if (!(status & I2C_STATUS_BUS_ACTIVE))
+					return 0;
+			} else {
+				return 0;
+			}
+		}
 
 		if (time_after(jiffies, timeout))
 			return -ETIMEDOUT;
 
-		usleep_range(qup->one_byte_t, qup->one_byte_t * 2);
+		usleep_range(len, len * 2);
 	}
 }
 
@@ -261,13 +280,13 @@ static void qup_i2c_set_write_mode(struct qup_i2c_dev *qup, struct i2c_msg *msg)
 	}
 }
 
-static void qup_i2c_issue_write(struct qup_i2c_dev *qup, struct i2c_msg *msg)
+static int qup_i2c_issue_write(struct qup_i2c_dev *qup, struct i2c_msg *msg)
 {
 	u32 addr = msg->addr << 1;
 	u32 qup_tag;
-	u32 opflags;
 	int idx;
 	u32 val;
+	int ret = 0;
 
 	if (qup->pos == 0) {
 		val = QUP_TAG_START | addr;
@@ -279,9 +298,10 @@ static void qup_i2c_issue_write(struct qup_i2c_dev *qup, struct i2c_msg *msg)
 
 	while (qup->pos < msg->len) {
 		/* Check that there's space in the FIFO for our pair */
-		opflags = readl(qup->base + QUP_OPERATIONAL);
-		if (opflags & QUP_OUT_FULL)
-			break;
+		ret = qup_i2c_wait_ready(qup, QUP_OUT_FULL, RESET_BIT,
+					 4 * ONE_BYTE);
+		if (ret)
+			return ret;
 
 		if (qup->pos == msg->len - 1)
 			qup_tag = QUP_TAG_STOP;
@@ -300,6 +320,8 @@ static void qup_i2c_issue_write(struct qup_i2c_dev *qup, struct i2c_msg *msg)
 		qup->pos++;
 		idx++;
 	}
+
+	return ret;
 }
 
 static int qup_i2c_write_one(struct qup_i2c_dev *qup, struct i2c_msg *msg)
@@ -325,7 +347,9 @@ static int qup_i2c_write_one(struct qup_i2c_dev *qup, struct i2c_msg *msg)
 		if (ret)
 			goto err;
 
-		qup_i2c_issue_write(qup, msg);
+		ret = qup_i2c_issue_write(qup, msg);
+		if (ret)
+			goto err;
 
 		ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
 		if (ret)
@@ -347,7 +371,7 @@ static int qup_i2c_write_one(struct qup_i2c_dev *qup, struct i2c_msg *msg)
 	} while (qup->pos < msg->len);
 
 	/* Wait for the outstanding data in the fifo to drain */
-	ret = qup_i2c_wait_writeready(qup);
+	ret = qup_i2c_wait_ready(qup, QUP_OUT_NOT_EMPTY, RESET_BIT, ONE_BYTE);
 
 err:
 	disable_irq(qup->irq);
@@ -384,18 +408,19 @@ static void qup_i2c_issue_read(struct qup_i2c_dev *qup, struct i2c_msg *msg)
 }
 
 
-static void qup_i2c_read_fifo(struct qup_i2c_dev *qup, struct i2c_msg *msg)
+static int qup_i2c_read_fifo(struct qup_i2c_dev *qup, struct i2c_msg *msg)
 {
-	u32 opflags;
 	u32 val = 0;
 	int idx;
+	int ret = 0;
 
 	for (idx = 0; qup->pos < msg->len; idx++) {
 		if ((idx & 1) == 0) {
 			/* Check that FIFO have data */
-			opflags = readl(qup->base + QUP_OPERATIONAL);
-			if (!(opflags & QUP_IN_NOT_EMPTY))
-				break;
+			ret = qup_i2c_wait_ready(qup, QUP_IN_NOT_EMPTY,
+						 SET_BIT, 4 * ONE_BYTE);
+			if (ret)
+				return ret;
 
 			/* Reading 2 words at time */
 			val = readl(qup->base + QUP_IN_FIFO_BASE);
@@ -405,6 +430,8 @@ static void qup_i2c_read_fifo(struct qup_i2c_dev *qup, struct i2c_msg *msg)
 			msg->buf[qup->pos++] = val >> QUP_MSW_SHIFT;
 		}
 	}
+
+	return ret;
 }
 
 static int qup_i2c_read_one(struct qup_i2c_dev *qup, struct i2c_msg *msg)
@@ -450,7 +477,9 @@ static int qup_i2c_read_one(struct qup_i2c_dev *qup, struct i2c_msg *msg)
 			goto err;
 		}
 
-		qup_i2c_read_fifo(qup, msg);
+		ret = qup_i2c_read_fifo(qup, msg);
+		if (ret)
+			goto err;
 	} while (qup->pos < msg->len);
 
 err:
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[toc] | [prev] | [next] | [standalone]

#1307222

On 01/12/2016 02:13 PM, Sricharan R wrote:
> i2c: qup: Add support for v2 tags and bam dma
>
> QUP from version 2.1.1 onwards, supports a new format of i2c command tags.
> Tag codes instructs the controller to perform a operation like read/write.
> This new tagging version supports and is required for adding bam dma
> capabilities. V2 tags supports transfer of more than 256 bytes in a single i2c
> transaction. Also adding bam dma support facilitates transferring each i2c_msg
> in i2c_msgs without a 'stop' bit in between which is required for some of
> the clients.
>
> Tested this series on apq8074 dragon board eeprom client on i2c bus1
>
> [V6] Added review tags and fixed a checkpatch warning in patch 4/6.
>
> [V5] Addressed few more comments from Ivan T. Ivanov.
>       Squashed patch 2 and 3 as no point in having only few lines of
>       common code between v1 and v2 tags for increased complexity.
>       Couple of non functional review comments fixes in patch 3, 4.
>       Added a change in patch 4 to have proper transfer completion in
>       a corner case. patch 5, 6 unchanged.
>
> [V4] Added a patch to factor out some common code.
>       Removed support for freq > 400KHZ as per comments.
>       Addressed comments from Ivan T. Ivanov to keep the code for
>       V2 support in a separate path.
>       Changed the authorship of V2 tags support patch.
>
> [V3] Added support to coalesce each i2c_msg in i2c_msgs for fifo and
>       block mode in Patch 2. Also addressed further code comments.
>
>       http://comments.gmane.org/gmane.linux.drivers.i2c/22497
>
> [V2] Addressed comments from Ivan T. Ivanov, Andy Gross [v1] Initial Version

For the series:

Tested-by: Archit Taneja <architt@codeaurora.org>

>
> Sricharan R (6):
>    i2c: qup: Change qup_wait_writeready function to use for all timeouts
>    i2c: qup: Add V2 tags support
>    i2c: qup: Transfer each i2c_msg in i2c_msgs without a stop bit
>    i2c: qup: Add bam dma capabilities
>    dts: msm8974: Add blsp2_bam dma node
>    dts: msm8974: Add dma channels for blsp2_i2c1 node
>
>   arch/arm/boot/dts/qcom-msm8974.dtsi |  14 +-
>   drivers/i2c/busses/i2c-qup.c        | 922 ++++++++++++++++++++++++++++++++++--
>   2 files changed, 887 insertions(+), 49 deletions(-)
>

-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora 
Forum, hosted by The Linux Foundation

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web