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path: root/drivers/i2c/busses/i2c-meson.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-meson.c')
-rw-r--r--drivers/i2c/busses/i2c-meson.c97
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)