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Commit 9dcb0e7b authored by Felipe Balbi's avatar Felipe Balbi Committed by Wolfram Sang
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i2c: omap: implement bus recovery 



implement bus recovery methods for i2c-omap
so we can recover from situations where SCL/SDA
are stuck low.

Signed-off-by: default avatarFelipe Balbi <balbi@ti.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent e9a02a3d

drivers/i2c/busses/i2c-omap.c

+65 −4
Original line number Original line Diff line number Diff line
@@ -482,10 +482,8 @@ static int omap_i2c_wait_for_bb(struct omap_i2c_dev *dev) 




	timeout = jiffies + OMAP_I2C_TIMEOUT;

	timeout = jiffies + OMAP_I2C_TIMEOUT;

	while (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {

	while (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {

		if (time_after(jiffies, timeout)) {

		if (time_after(jiffies, timeout))

			dev_warn(dev->dev, "timeout waiting for bus ready\n");

			return i2c_recover_bus(&dev->adapter);

			return -ETIMEDOUT;

		}

		msleep(1);

		msleep(1);

	}

	}
@@ -1210,6 +1208,68 @@ MODULE_DEVICE_TABLE(of, omap_i2c_of_match); 
#define OMAP_I2C_SCHEME_0		0

#define OMAP_I2C_SCHEME_0		0

#define OMAP_I2C_SCHEME_1		1

#define OMAP_I2C_SCHEME_1		1





static int omap_i2c_get_scl(struct i2c_adapter *adap)

{

	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);

	u32 reg;



	reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);



	return reg & OMAP_I2C_SYSTEST_SCL_I_FUNC;

}



static int omap_i2c_get_sda(struct i2c_adapter *adap)

{

	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);

	u32 reg;



	reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);



	return reg & OMAP_I2C_SYSTEST_SDA_I_FUNC;

}



static void omap_i2c_set_scl(struct i2c_adapter *adap, int val)

{

	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);

	u32 reg;



	reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);

	if (val)

		reg |= OMAP_I2C_SYSTEST_SCL_O;

	else

		reg &= ~OMAP_I2C_SYSTEST_SCL_O;

	omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg);

}



static void omap_i2c_prepare_recovery(struct i2c_adapter *adap)

{

	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);

	u32 reg;



	reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);

	reg |= OMAP_I2C_SYSTEST_ST_EN;

	omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg);

}



static void omap_i2c_unprepare_recovery(struct i2c_adapter *adap)

{

	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);

	u32 reg;



	reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);

	reg &= ~OMAP_I2C_SYSTEST_ST_EN;

	omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg);

}



static struct i2c_bus_recovery_info omap_i2c_bus_recovery_info = {

	.get_scl		= omap_i2c_get_scl,

	.get_sda		= omap_i2c_get_sda,

	.set_scl		= omap_i2c_set_scl,

	.prepare_recovery	= omap_i2c_prepare_recovery,

	.unprepare_recovery	= omap_i2c_unprepare_recovery,

	.recover_bus		= i2c_generic_scl_recovery,

};



static int

static int

omap_i2c_probe(struct platform_device *pdev)

omap_i2c_probe(struct platform_device *pdev)

{

{
@@ -1359,6 +1419,7 @@ omap_i2c_probe(struct platform_device *pdev) 
	adap->algo = &omap_i2c_algo;

	adap->algo = &omap_i2c_algo;

	adap->dev.parent = &pdev->dev;

	adap->dev.parent = &pdev->dev;

	adap->dev.of_node = pdev->dev.of_node;

	adap->dev.of_node = pdev->dev.of_node;

	adap->bus_recovery_info = &omap_i2c_bus_recovery_info;





	/* i2c device drivers may be active on return from add_adapter() */

	/* i2c device drivers may be active on return from add_adapter() */

	adap->nr = pdev->id;

	adap->nr = pdev->id;