Add support for atomic transfers using polling mode with interrupts
intentionally disabled. This removes the warning introduced by commit
63b96983a5dd ("i2c: core: introduce callbacks for atomic transfers")
during system reboot and power off.
Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
---
v2:
- adjusted some names as pointed by Andi
---
drivers/i2c/busses/i2c-exynos5.c | 51 ++++++++++++++++++++++++++++++--
1 file changed, 48 insertions(+), 3 deletions(-)
diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c
index 2b0b9cdffa86..3ff398145b7b 100644
--- a/drivers/i2c/busses/i2c-exynos5.c
+++ b/drivers/i2c/busses/i2c-exynos5.c
@@ -162,7 +162,8 @@
#define HSI2C_MASTER_ID(x) ((x & 0xff) << 24)
#define MASTER_ID(x) ((x & 0x7) + 0x08)
-#define EXYNOS5_I2C_TIMEOUT (msecs_to_jiffies(100))
+#define EXYNOS5_I2C_TIMEOUT_MS (100)
+#define EXYNOS5_I2C_TIMEOUT (msecs_to_jiffies(EXYNOS5_I2C_TIMEOUT_MS))
enum i2c_type_exynos {
I2C_TYPE_EXYNOS5,
@@ -194,6 +195,11 @@ struct exynos5_i2c {
*/
int trans_done;
+ /*
+ * Called from atomic context, don't use interrupts.
+ */
+ int no_irqs;
+
/* Controller operating frequency */
unsigned int op_clock;
@@ -711,6 +717,24 @@ static void exynos5_i2c_message_start(struct exynos5_i2c *i2c, int stop)
spin_unlock_irqrestore(&i2c->lock, flags);
}
+static bool exynos5_i2c_poll_irqs_timeout(struct exynos5_i2c *i2c,
+ unsigned long timeout_ms)
+{
+ ktime_t start, now;
+
+ start = now = ktime_get();
+ while (ktime_ms_delta(now, start) < timeout_ms &&
+ !((i2c->trans_done && (i2c->msg->len == i2c->msg_ptr)) ||
+ (i2c->state < 0))) {
+ while (readl(i2c->regs + HSI2C_INT_ENABLE) &
+ readl(i2c->regs + HSI2C_INT_STATUS))
+ exynos5_i2c_irq(i2c->irq, i2c);
+ usleep_range(100, 200);
+ now = ktime_get();
+ }
+ return ktime_ms_delta(now, start) < timeout_ms;
+}
+
static int exynos5_i2c_xfer_msg(struct exynos5_i2c *i2c,
struct i2c_msg *msgs, int stop)
{
@@ -725,8 +749,13 @@ static int exynos5_i2c_xfer_msg(struct exynos5_i2c *i2c,
exynos5_i2c_message_start(i2c, stop);
- timeout = wait_for_completion_timeout(&i2c->msg_complete,
- EXYNOS5_I2C_TIMEOUT);
+ if (!i2c->no_irqs)
+ timeout = wait_for_completion_timeout(&i2c->msg_complete,
+ EXYNOS5_I2C_TIMEOUT);
+ else
+ timeout = exynos5_i2c_poll_irqs_timeout(i2c,
+ EXYNOS5_I2C_TIMEOUT_MS);
+
if (timeout == 0)
ret = -ETIMEDOUT;
else
@@ -777,6 +806,21 @@ static int exynos5_i2c_xfer(struct i2c_adapter *adap,
return ret ?: num;
}
+static int exynos5_i2c_xfer_atomic(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num)
+{
+ struct exynos5_i2c *i2c = adap->algo_data;
+ int ret;
+
+ disable_irq(i2c->irq);
+ i2c->no_irqs = true;
+ ret = exynos5_i2c_xfer(adap, msgs, num);
+ i2c->no_irqs = false;
+ enable_irq(i2c->irq);
+
+ return ret;
+}
+
static u32 exynos5_i2c_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
@@ -784,6 +828,7 @@ static u32 exynos5_i2c_func(struct i2c_adapter *adap)
static const struct i2c_algorithm exynos5_i2c_algorithm = {
.master_xfer = exynos5_i2c_xfer,
+ .master_xfer_atomic = exynos5_i2c_xfer_atomic,
.functionality = exynos5_i2c_func,
};
--
2.34.1
