Commit 445094c8 authored by Marek Szyprowski's avatar Marek Szyprowski Committed by Wolfram Sang
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i2c: exynos5: add support for atomic transfers 



Add support for atomic transfers using polling mode with interrupts
intentionally disabled. This removes the warning introduced by commit
63b96983 ("i2c: core: introduce callbacks for atomic transfers")
during system reboot and power-off.

Signed-off-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: default avatarAndi Shyti <andi.shyti@kernel.org>
Signed-off-by: default avatarWolfram Sang <wsa@kernel.org>
parent 29c9e85d

drivers/i2c/busses/i2c-exynos5.c

+44 −2
Original line number Diff line number Diff line
@@ -194,6 +194,11 @@ struct exynos5_i2c { 
	 */

	int			trans_done;



	/*

	 * Called from atomic context, don't use interrupts.

	 */

	unsigned int		atomic;



	/* Controller operating frequency */

	unsigned int		op_clock;
@@ -711,6 +716,22 @@ 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)

{

	unsigned long time_left = jiffies + timeout;



	while (time_before(jiffies, time_left) &&

	       !((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);

	}

	return time_before(jiffies, time_left);

}



static int exynos5_i2c_xfer_msg(struct exynos5_i2c *i2c,

			      struct i2c_msg *msgs, int stop)

{
@@ -725,8 +746,13 @@ static int exynos5_i2c_xfer_msg(struct exynos5_i2c *i2c, 


	exynos5_i2c_message_start(i2c, stop);



	if (!i2c->atomic)

		timeout = wait_for_completion_timeout(&i2c->msg_complete,

						      EXYNOS5_I2C_TIMEOUT);

	else

		timeout = exynos5_i2c_poll_irqs_timeout(i2c,

							EXYNOS5_I2C_TIMEOUT);



	if (timeout == 0)

		ret = -ETIMEDOUT;

	else
@@ -777,6 +803,21 @@ 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->atomic = true;

	ret = exynos5_i2c_xfer(adap, msgs, num);

	i2c->atomic = 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 +825,7 @@ 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,

};