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Commit 4729cbe0 authored by Jan Glauber's avatar Jan Glauber Committed by Wolfram Sang
Browse files

i2c: octeon: Add support for cn78xx chips 



cn78xx has a different interrupt architecture, so we have to manage
the interrupts differently.

Signed-off-by: default avatarDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: default avatarJan Glauber <jglauber@cavium.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent d1fbff89

Documentation/devicetree/bindings/i2c/i2c-octeon.txt

+6 −0
Original line number Diff line number Diff line
@@ -4,6 +4,12 @@ 


  Compatibility with all cn3XXX, cn5XXX and cn6XXX SOCs.



  or



  compatible: "cavium,octeon-7890-twsi"



  Compatibility with cn78XX SOCs.



- reg: The base address of the TWSI/I2C bus controller register bank.



- #address-cells: Must be <1>.

drivers/i2c/busses/i2c-octeon.c

+119 −10
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
 * warranty of any kind, whether express or implied.

 */



#include <linux/atomic.h>

#include <linux/platform_device.h>

#include <linux/interrupt.h>

#include <linux/kernel.h>
@@ -112,11 +113,18 @@ struct octeon_i2c { 
	wait_queue_head_t queue;

	struct i2c_adapter adap;

	int irq;

	int hlc_irq;		/* For cn7890 only */

	u32 twsi_freq;

	int sys_freq;

	void __iomem *twsi_base;

	struct device *dev;

	bool hlc_enabled;

	void (*int_enable)(struct octeon_i2c *);

	void (*int_disable)(struct octeon_i2c *);

	void (*hlc_int_enable)(struct octeon_i2c *);

	void (*hlc_int_disable)(struct octeon_i2c *);

	atomic_t int_enable_cnt;

	atomic_t hlc_int_enable_cnt;

};



static void octeon_i2c_writeq_flush(u64 val, void __iomem *addr)
@@ -216,6 +224,58 @@ static void octeon_i2c_int_disable(struct octeon_i2c *i2c) 
	octeon_i2c_write_int(i2c, 0);

}



/**

 * octeon_i2c_int_enable78 - enable the CORE interrupt

 * @i2c: The struct octeon_i2c

 *

 * The interrupt will be asserted when there is non-STAT_IDLE state in the

 * SW_TWSI_EOP_TWSI_STAT register.

 */

static void octeon_i2c_int_enable78(struct octeon_i2c *i2c)

{

	atomic_inc_return(&i2c->int_enable_cnt);

	enable_irq(i2c->irq);

}



static void __octeon_i2c_irq_disable(atomic_t *cnt, int irq)

{

	int count;



	/*

	 * The interrupt can be disabled in two places, but we only

	 * want to make the disable_irq_nosync() call once, so keep

	 * track with the atomic variable.

	 */

	count = atomic_dec_if_positive(cnt);

	if (count >= 0)

		disable_irq_nosync(irq);

}



/* disable the CORE interrupt */

static void octeon_i2c_int_disable78(struct octeon_i2c *i2c)

{

	__octeon_i2c_irq_disable(&i2c->int_enable_cnt, i2c->irq);

}



/**

 * octeon_i2c_hlc_int_enable78 - enable the ST interrupt

 * @i2c: The struct octeon_i2c

 *

 * The interrupt will be asserted when there is non-STAT_IDLE state in

 * the SW_TWSI_EOP_TWSI_STAT register.

 */

static void octeon_i2c_hlc_int_enable78(struct octeon_i2c *i2c)

{

	atomic_inc_return(&i2c->hlc_int_enable_cnt);

	enable_irq(i2c->hlc_irq);

}



/* disable the ST interrupt */

static void octeon_i2c_hlc_int_disable78(struct octeon_i2c *i2c)

{

	__octeon_i2c_irq_disable(&i2c->hlc_int_enable_cnt, i2c->hlc_irq);

}



/*

 * Cleanup low-level state & enable high-level controller.

 */
@@ -262,7 +322,18 @@ static irqreturn_t octeon_i2c_isr(int irq, void *dev_id) 
{

	struct octeon_i2c *i2c = dev_id;



	octeon_i2c_int_disable(i2c);

	i2c->int_disable(i2c);

	wake_up(&i2c->queue);



	return IRQ_HANDLED;

}



/* HLC interrupt service routine */

static irqreturn_t octeon_i2c_hlc_isr78(int irq, void *dev_id)

{

	struct octeon_i2c *i2c = dev_id;



	i2c->hlc_int_disable(i2c);

	wake_up(&i2c->queue);



	return IRQ_HANDLED;
@@ -283,10 +354,10 @@ static int octeon_i2c_wait(struct octeon_i2c *i2c) 
{

	long time_left;



	octeon_i2c_int_enable(i2c);

	i2c->int_enable(i2c);

	time_left = wait_event_timeout(i2c->queue, octeon_i2c_test_iflg(i2c),

				       i2c->adap.timeout);

	octeon_i2c_int_disable(i2c);

	i2c->int_disable(i2c);

	if (!time_left) {

		dev_dbg(i2c->dev, "%s: timeout\n", __func__);

		return -ETIMEDOUT;
@@ -384,11 +455,11 @@ static int octeon_i2c_hlc_wait(struct octeon_i2c *i2c) 
{

	int time_left;



	octeon_i2c_hlc_int_enable(i2c);

	i2c->hlc_int_enable(i2c);

	time_left = wait_event_timeout(i2c->queue,

				       octeon_i2c_hlc_test_ready(i2c),

				       i2c->adap.timeout);

	octeon_i2c_int_disable(i2c);

	i2c->hlc_int_disable(i2c);

	if (!time_left) {

		octeon_i2c_hlc_int_clear(i2c);

		return -ETIMEDOUT;
@@ -946,14 +1017,26 @@ static struct i2c_adapter octeon_i2c_ops = { 
static int octeon_i2c_probe(struct platform_device *pdev)

{

	struct device_node *node = pdev->dev.of_node;

	int irq, result = 0, hlc_irq = 0;

	struct resource *res_mem;

	struct octeon_i2c *i2c;

	int irq, result = 0;

	bool cn78xx_style;



	cn78xx_style = of_device_is_compatible(node, "cavium,octeon-7890-twsi");

	if (cn78xx_style) {

		hlc_irq = platform_get_irq(pdev, 0);

		if (hlc_irq < 0)

			return hlc_irq;



		irq = platform_get_irq(pdev, 2);

		if (irq < 0)

			return irq;

	} else {

		/* All adaptors have an irq.  */

		irq = platform_get_irq(pdev, 0);

		if (irq < 0)

			return irq;

	}



	i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL);

	if (!i2c) {
@@ -988,6 +1071,31 @@ static int octeon_i2c_probe(struct platform_device *pdev) 


	i2c->irq = irq;



	if (cn78xx_style) {

		i2c->hlc_irq = hlc_irq;



		i2c->int_enable = octeon_i2c_int_enable78;

		i2c->int_disable = octeon_i2c_int_disable78;

		i2c->hlc_int_enable = octeon_i2c_hlc_int_enable78;

		i2c->hlc_int_disable = octeon_i2c_hlc_int_disable78;



		irq_set_status_flags(i2c->irq, IRQ_NOAUTOEN);

		irq_set_status_flags(i2c->hlc_irq, IRQ_NOAUTOEN);



		result = devm_request_irq(&pdev->dev, i2c->hlc_irq,

					  octeon_i2c_hlc_isr78, 0,

					  DRV_NAME, i2c);

		if (result < 0) {

			dev_err(i2c->dev, "failed to attach interrupt\n");

			goto out;

		}

	} else {

		i2c->int_enable = octeon_i2c_int_enable;

		i2c->int_disable = octeon_i2c_int_disable;

		i2c->hlc_int_enable = octeon_i2c_hlc_int_enable;

		i2c->hlc_int_disable = octeon_i2c_int_disable;

	}



	result = devm_request_irq(&pdev->dev, i2c->irq,

				  octeon_i2c_isr, 0, DRV_NAME, i2c);

	if (result < 0) {
@@ -1034,6 +1142,7 @@ static int octeon_i2c_remove(struct platform_device *pdev) 


static const struct of_device_id octeon_i2c_match[] = {

	{ .compatible = "cavium,octeon-3860-twsi", },

	{ .compatible = "cavium,octeon-7890-twsi", },

	{},

};

MODULE_DEVICE_TABLE(of, octeon_i2c_match);