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i2c: qup: Change qup_wait_writeready function to use for all timeouts
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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>
Tested-by: Archit Taneja <architt@codeaurora.org>
Tested-by: Telkar Nagender <ntelkar@codeaurora.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
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Sricharan R authored and Wolfram Sang committed Feb 12, 2016
1 parent 50a5ba8 commit c4f0c5f
Showing 1 changed file with 48 additions and 19 deletions.
67 changes: 48 additions & 19 deletions drivers/i2c/busses/i2c-qup.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down Expand Up @@ -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);
}
}

Expand All @@ -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;
Expand All @@ -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;
Expand All @@ -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)
Expand All @@ -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)
Expand All @@ -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);
Expand Down Expand Up @@ -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);
Expand All @@ -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)
Expand Down Expand Up @@ -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:
Expand Down

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