diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-qup.c')
-rw-r--r-- | drivers/i2c/busses/i2c-qup.c | 67 |
1 files 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: |