diff options
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-meson.c | 97 |
1 files changed, 65 insertions, 32 deletions
diff --git a/drivers/i2c/busses/i2c-meson.c b/drivers/i2c/busses/i2c-meson.c index 1e2647f9a2a7..06b3bed78421 100644 --- a/drivers/i2c/busses/i2c-meson.c +++ b/drivers/i2c/busses/i2c-meson.c @@ -10,6 +10,7 @@ #include <linux/i2c.h> #include <linux/interrupt.h> #include <linux/io.h> +#include <linux/iopoll.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/of.h> @@ -213,6 +214,30 @@ static void meson_i2c_prepare_xfer(struct meson_i2c *i2c) writel(i2c->tokens[1], i2c->regs + REG_TOK_LIST1); } +static void meson_i2c_transfer_complete(struct meson_i2c *i2c, u32 ctrl) +{ + if (ctrl & REG_CTRL_ERROR) { + /* + * The bit is set when the IGNORE_NAK bit is cleared + * and the device didn't respond. In this case, the + * I2C controller automatically generates a STOP + * condition. + */ + dev_dbg(i2c->dev, "error bit set\n"); + i2c->error = -ENXIO; + i2c->state = STATE_IDLE; + } else { + if (i2c->state == STATE_READ && i2c->count) + meson_i2c_get_data(i2c, i2c->msg->buf + i2c->pos, + i2c->count); + + i2c->pos += i2c->count; + + if (i2c->pos >= i2c->msg->len) + i2c->state = STATE_IDLE; + } +} + static irqreturn_t meson_i2c_irq(int irqno, void *dev_id) { struct meson_i2c *i2c = dev_id; @@ -232,27 +257,9 @@ static irqreturn_t meson_i2c_irq(int irqno, void *dev_id) return IRQ_NONE; } - if (ctrl & REG_CTRL_ERROR) { - /* - * The bit is set when the IGNORE_NAK bit is cleared - * and the device didn't respond. In this case, the - * I2C controller automatically generates a STOP - * condition. - */ - dev_dbg(i2c->dev, "error bit set\n"); - i2c->error = -ENXIO; - i2c->state = STATE_IDLE; - complete(&i2c->done); - goto out; - } - - if (i2c->state == STATE_READ && i2c->count) - meson_i2c_get_data(i2c, i2c->msg->buf + i2c->pos, i2c->count); + meson_i2c_transfer_complete(i2c, ctrl); - i2c->pos += i2c->count; - - if (i2c->pos >= i2c->msg->len) { - i2c->state = STATE_IDLE; + if (i2c->state == STATE_IDLE) { complete(&i2c->done); goto out; } @@ -279,10 +286,11 @@ static void meson_i2c_do_start(struct meson_i2c *i2c, struct i2c_msg *msg) } static int meson_i2c_xfer_msg(struct meson_i2c *i2c, struct i2c_msg *msg, - int last) + int last, bool atomic) { unsigned long time_left, flags; int ret = 0; + u32 ctrl; i2c->msg = msg; i2c->last = last; @@ -300,13 +308,24 @@ static int meson_i2c_xfer_msg(struct meson_i2c *i2c, struct i2c_msg *msg, i2c->state = (msg->flags & I2C_M_RD) ? STATE_READ : STATE_WRITE; meson_i2c_prepare_xfer(i2c); - reinit_completion(&i2c->done); + + if (!atomic) + reinit_completion(&i2c->done); /* Start the transfer */ meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_START, REG_CTRL_START); - time_left = msecs_to_jiffies(I2C_TIMEOUT_MS); - time_left = wait_for_completion_timeout(&i2c->done, time_left); + if (atomic) { + ret = readl_poll_timeout_atomic(i2c->regs + REG_CTRL, ctrl, + !(ctrl & REG_CTRL_STATUS), + 10, I2C_TIMEOUT_MS * 1000); + } else { + time_left = msecs_to_jiffies(I2C_TIMEOUT_MS); + time_left = wait_for_completion_timeout(&i2c->done, time_left); + + if (!time_left) + ret = -ETIMEDOUT; + } /* * Protect access to i2c struct and registers from interrupt @@ -315,13 +334,14 @@ static int meson_i2c_xfer_msg(struct meson_i2c *i2c, struct i2c_msg *msg, */ spin_lock_irqsave(&i2c->lock, flags); + if (atomic && !ret) + meson_i2c_transfer_complete(i2c, ctrl); + /* Abort any active operation */ meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_START, 0); - if (!time_left) { + if (ret) i2c->state = STATE_IDLE; - ret = -ETIMEDOUT; - } if (i2c->error) ret = i2c->error; @@ -331,8 +351,8 @@ static int meson_i2c_xfer_msg(struct meson_i2c *i2c, struct i2c_msg *msg, return ret; } -static int meson_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, - int num) +static int meson_i2c_xfer_messages(struct i2c_adapter *adap, + struct i2c_msg *msgs, int num, bool atomic) { struct meson_i2c *i2c = adap->algo_data; int i, ret = 0; @@ -340,7 +360,7 @@ static int meson_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, clk_enable(i2c->clk); for (i = 0; i < num; i++) { - ret = meson_i2c_xfer_msg(i2c, msgs + i, i == num - 1); + ret = meson_i2c_xfer_msg(i2c, msgs + i, i == num - 1, atomic); if (ret) break; } @@ -350,14 +370,27 @@ static int meson_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, return ret ?: i; } +static int meson_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, + int num) +{ + return meson_i2c_xfer_messages(adap, msgs, num, false); +} + +static int meson_i2c_xfer_atomic(struct i2c_adapter *adap, + struct i2c_msg *msgs, int num) +{ + return meson_i2c_xfer_messages(adap, msgs, num, true); +} + static u32 meson_i2c_func(struct i2c_adapter *adap) { return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; } static const struct i2c_algorithm meson_i2c_algorithm = { - .master_xfer = meson_i2c_xfer, - .functionality = meson_i2c_func, + .master_xfer = meson_i2c_xfer, + .master_xfer_atomic = meson_i2c_xfer_atomic, + .functionality = meson_i2c_func, }; static int meson_i2c_probe(struct platform_device *pdev) |