Commit 1ae49a15 authored by Russell King's avatar Russell King Committed by Wolfram Sang
Browse files

i2c: pxa: re-arrange functions to flow better 



Re-arrange the PXA I2C code to avoid forward declarations, and keep
similar functionality (e.g. the non-IRQ mode support) together. This
improves code readability.

Signed-off-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: default avatarWolfram Sang <wsa@kernel.org>
parent 8de32da2

drivers/i2c/busses/i2c-pxa.c

+162 −163
Original line number Diff line number Diff line
@@ -326,7 +326,6 @@ static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why) 
#endif /* ifdef DEBUG / else */



static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);

static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id);



static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)

{
@@ -741,34 +740,6 @@ static inline void i2c_pxa_stop_message(struct pxa_i2c *i2c) 
	writel(icr, _ICR(i2c));

}



static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)

{

	/* make timeout the same as for interrupt based functions */

	long timeout = 2 * DEF_TIMEOUT;



	/*

	 * Wait for the bus to become free.

	 */

	while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {

		udelay(1000);

		show_state(i2c);

	}



	if (timeout < 0) {

		show_state(i2c);

		dev_err(&i2c->adap.dev,

			"i2c_pxa: timeout waiting for bus free\n");

		return I2C_RETRY;

	}



	/*

	 * Set master mode.

	 */

	writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));



	return 0;

}



/*

 * PXA I2C send master code

 * 1. Load master code to IDBR and send it.
@@ -797,140 +768,6 @@ static int i2c_pxa_send_mastercode(struct pxa_i2c *i2c) 
	return (timeout == 0) ? I2C_RETRY : 0;

}



static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,

			       struct i2c_msg *msg, int num)

{

	unsigned long timeout = 500000; /* 5 seconds */

	int ret = 0;



	ret = i2c_pxa_pio_set_master(i2c);

	if (ret)

		goto out;



	i2c->msg = msg;

	i2c->msg_num = num;

	i2c->msg_idx = 0;

	i2c->msg_ptr = 0;

	i2c->irqlogidx = 0;



	i2c_pxa_start_message(i2c);



	while (i2c->msg_num > 0 && --timeout) {

		i2c_pxa_handler(0, i2c);

		udelay(10);

	}



	i2c_pxa_stop_message(i2c);



	/*

	 * We place the return code in i2c->msg_idx.

	 */

	ret = i2c->msg_idx;



out:

	if (timeout == 0) {

		i2c_pxa_scream_blue_murder(i2c, "timeout");

		ret = I2C_RETRY;

	}



	return ret;

}



/*

 * We are protected by the adapter bus mutex.

 */

static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)

{

	long timeout;

	int ret;



	/*

	 * Wait for the bus to become free.

	 */

	ret = i2c_pxa_wait_bus_not_busy(i2c);

	if (ret) {

		dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");

		goto out;

	}



	/*

	 * Set master mode.

	 */

	ret = i2c_pxa_set_master(i2c);

	if (ret) {

		dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);

		goto out;

	}



	if (i2c->high_mode) {

		ret = i2c_pxa_send_mastercode(i2c);

		if (ret) {

			dev_err(&i2c->adap.dev, "i2c_pxa_send_mastercode timeout\n");

			goto out;

			}

	}



	spin_lock_irq(&i2c->lock);



	i2c->msg = msg;

	i2c->msg_num = num;

	i2c->msg_idx = 0;

	i2c->msg_ptr = 0;

	i2c->irqlogidx = 0;



	i2c_pxa_start_message(i2c);



	spin_unlock_irq(&i2c->lock);



	/*

	 * The rest of the processing occurs in the interrupt handler.

	 */

	timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);

	i2c_pxa_stop_message(i2c);



	/*

	 * We place the return code in i2c->msg_idx.

	 */

	ret = i2c->msg_idx;



	if (!timeout && i2c->msg_num) {

		i2c_pxa_scream_blue_murder(i2c, "timeout");

		ret = I2C_RETRY;

	}



 out:

	return ret;

}



static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,

			    struct i2c_msg msgs[], int num)

{

	struct pxa_i2c *i2c = adap->algo_data;

	int ret, i;



	/* If the I2C controller is disabled we need to reset it

	  (probably due to a suspend/resume destroying state). We do

	  this here as we can then avoid worrying about resuming the

	  controller before its users. */

	if (!(readl(_ICR(i2c)) & ICR_IUE))

		i2c_pxa_reset(i2c);



	for (i = adap->retries; i >= 0; i--) {

		ret = i2c_pxa_do_pio_xfer(i2c, msgs, num);

		if (ret != I2C_RETRY)

			goto out;



		if (i2c_debug)

			dev_dbg(&adap->dev, "Retrying transmission\n");

		udelay(100);

	}

	i2c_pxa_scream_blue_murder(i2c, "exhausted retries");

	ret = -EREMOTEIO;

 out:

	i2c_pxa_set_slave(i2c, ret);

	return ret;

}



/*

 * i2c_pxa_master_complete - complete the message and wake up.

 */
@@ -1137,6 +974,71 @@ static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id) 
	return IRQ_HANDLED;

}



/*

 * We are protected by the adapter bus mutex.

 */

static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)

{

	long timeout;

	int ret;



	/*

	 * Wait for the bus to become free.

	 */

	ret = i2c_pxa_wait_bus_not_busy(i2c);

	if (ret) {

		dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");

		goto out;

	}



	/*

	 * Set master mode.

	 */

	ret = i2c_pxa_set_master(i2c);

	if (ret) {

		dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);

		goto out;

	}



	if (i2c->high_mode) {

		ret = i2c_pxa_send_mastercode(i2c);

		if (ret) {

			dev_err(&i2c->adap.dev, "i2c_pxa_send_mastercode timeout\n");

			goto out;

			}

	}



	spin_lock_irq(&i2c->lock);



	i2c->msg = msg;

	i2c->msg_num = num;

	i2c->msg_idx = 0;

	i2c->msg_ptr = 0;

	i2c->irqlogidx = 0;



	i2c_pxa_start_message(i2c);



	spin_unlock_irq(&i2c->lock);



	/*

	 * The rest of the processing occurs in the interrupt handler.

	 */

	timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);

	i2c_pxa_stop_message(i2c);



	/*

	 * We place the return code in i2c->msg_idx.

	 */

	ret = i2c->msg_idx;



	if (!timeout && i2c->msg_num) {

		i2c_pxa_scream_blue_murder(i2c, "timeout");

		ret = I2C_RETRY;

	}



 out:

	return ret;

}



static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)

{
@@ -1174,6 +1076,103 @@ static const struct i2c_algorithm i2c_pxa_algorithm = { 
#endif

};



/* Non-interrupt mode support */

static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)

{

	/* make timeout the same as for interrupt based functions */

	long timeout = 2 * DEF_TIMEOUT;



	/*

	 * Wait for the bus to become free.

	 */

	while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {

		udelay(1000);

		show_state(i2c);

	}



	if (timeout < 0) {

		show_state(i2c);

		dev_err(&i2c->adap.dev,

			"i2c_pxa: timeout waiting for bus free\n");

		return I2C_RETRY;

	}



	/*

	 * Set master mode.

	 */

	writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));



	return 0;

}



static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,

			       struct i2c_msg *msg, int num)

{

	unsigned long timeout = 500000; /* 5 seconds */

	int ret = 0;



	ret = i2c_pxa_pio_set_master(i2c);

	if (ret)

		goto out;



	i2c->msg = msg;

	i2c->msg_num = num;

	i2c->msg_idx = 0;

	i2c->msg_ptr = 0;

	i2c->irqlogidx = 0;



	i2c_pxa_start_message(i2c);



	while (i2c->msg_num > 0 && --timeout) {

		i2c_pxa_handler(0, i2c);

		udelay(10);

	}



	i2c_pxa_stop_message(i2c);



	/*

	 * We place the return code in i2c->msg_idx.

	 */

	ret = i2c->msg_idx;



out:

	if (timeout == 0) {

		i2c_pxa_scream_blue_murder(i2c, "timeout");

		ret = I2C_RETRY;

	}



	return ret;

}



static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,

			    struct i2c_msg msgs[], int num)

{

	struct pxa_i2c *i2c = adap->algo_data;

	int ret, i;



	/* If the I2C controller is disabled we need to reset it

	  (probably due to a suspend/resume destroying state). We do

	  this here as we can then avoid worrying about resuming the

	  controller before its users. */

	if (!(readl(_ICR(i2c)) & ICR_IUE))

		i2c_pxa_reset(i2c);



	for (i = adap->retries; i >= 0; i--) {

		ret = i2c_pxa_do_pio_xfer(i2c, msgs, num);

		if (ret != I2C_RETRY)

			goto out;



		if (i2c_debug)

			dev_dbg(&adap->dev, "Retrying transmission\n");

		udelay(100);

	}

	i2c_pxa_scream_blue_murder(i2c, "exhausted retries");

	ret = -EREMOTEIO;

 out:

	i2c_pxa_set_slave(i2c, ret);

	return ret;

}



static const struct i2c_algorithm i2c_pxa_pio_algorithm = {

	.master_xfer	= i2c_pxa_pio_xfer,

	.functionality	= i2c_pxa_functionality,