[PATCH V5 2/6] i2c: qup: Add V2 tags support

Sricharan R
2015-11-17T11:47:13Z

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));