Commit c31d0a00 authored by Niklas Söderlund's avatar Niklas Söderlund Committed by Wolfram Sang
Browse files

i2c: emev2: add slave support 



Add I2C slave provider using the generic slave interface.

Signed-off-by: default avatarNiklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent 7a852b02

drivers/i2c/busses/i2c-emev2.c

+111 −1
Original line number Diff line number Diff line
@@ -71,6 +71,7 @@ struct em_i2c_device { 
	struct i2c_adapter adap;

	struct completion msg_done;

	struct clk *sclk;

	struct i2c_client *slave;

};



static inline void em_clear_set_bit(struct em_i2c_device *priv, u8 clear, u8 set, u8 reg)
@@ -226,22 +227,131 @@ static int em_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 
	return num;

}



static bool em_i2c_slave_irq(struct em_i2c_device *priv)

{

	u8 status, value;

	enum i2c_slave_event event;

	int ret;



	if (!priv->slave)

		return false;



	status = readb(priv->base + I2C_OFS_IICSE0);



	/* Extension code, do not participate */

	if (status & I2C_BIT_EXC0) {

		em_clear_set_bit(priv, 0, I2C_BIT_LREL0, I2C_OFS_IICC0);

		return true;

	}



	/* Stop detected, we don't know if it's for slave or master */

	if (status & I2C_BIT_SPD0) {

		/* Notify slave device */

		i2c_slave_event(priv->slave, I2C_SLAVE_STOP, &value);

		/* Pretend we did not handle the interrupt */

		return false;

	}



	/* Only handle interrupts addressed to us */

	if (!(status & I2C_BIT_COI0))

		return false;



	/* Enable stop interrupts */

	em_clear_set_bit(priv, 0, I2C_BIT_SPIE0, I2C_OFS_IICC0);



	/* Transmission or Reception */

	if (status & I2C_BIT_TRC0) {

		if (status & I2C_BIT_ACKD0) {

			/* 9 bit interrupt mode */

			em_clear_set_bit(priv, 0, I2C_BIT_WTIM0, I2C_OFS_IICC0);



			/* Send data */

			event = status & I2C_BIT_STD0 ?

				I2C_SLAVE_READ_REQUESTED :

				I2C_SLAVE_READ_PROCESSED;

			i2c_slave_event(priv->slave, event, &value);

			writeb(value, priv->base + I2C_OFS_IIC0);

		} else {

			/* NACK, stop transmitting */

			em_clear_set_bit(priv, 0, I2C_BIT_LREL0, I2C_OFS_IICC0);

		}

	} else {

		/* 8 bit interrupt mode */

		em_clear_set_bit(priv, I2C_BIT_WTIM0, I2C_BIT_ACKE0,

				I2C_OFS_IICC0);

		em_clear_set_bit(priv, I2C_BIT_WTIM0, I2C_BIT_WREL0,

				I2C_OFS_IICC0);



		if (status & I2C_BIT_STD0) {

			i2c_slave_event(priv->slave, I2C_SLAVE_WRITE_REQUESTED,

					&value);

		} else {

			/* Recv data */

			value = readb(priv->base + I2C_OFS_IIC0);

			ret = i2c_slave_event(priv->slave,

					I2C_SLAVE_WRITE_RECEIVED, &value);

			if (ret < 0)

				em_clear_set_bit(priv, I2C_BIT_ACKE0, 0,

						I2C_OFS_IICC0);

		}

	}



	return true;

}



static irqreturn_t em_i2c_irq_handler(int this_irq, void *dev_id)

{

	struct em_i2c_device *priv = dev_id;



	if (em_i2c_slave_irq(priv))

		return IRQ_HANDLED;



	complete(&priv->msg_done);



	return IRQ_HANDLED;

}



static u32 em_i2c_func(struct i2c_adapter *adap)

{

	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;

	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SLAVE;

}



static int em_i2c_reg_slave(struct i2c_client *slave)

{

	struct em_i2c_device *priv = i2c_get_adapdata(slave->adapter);



	if (priv->slave)

		return -EBUSY;



	if (slave->flags & I2C_CLIENT_TEN)

		return -EAFNOSUPPORT;



	priv->slave = slave;



	/* Set slave address */

	writeb(slave->addr << 1, priv->base + I2C_OFS_SVA0);



	return 0;

}



static int em_i2c_unreg_slave(struct i2c_client *slave)

{

	struct em_i2c_device *priv = i2c_get_adapdata(slave->adapter);



	WARN_ON(!priv->slave);



	writeb(0, priv->base + I2C_OFS_SVA0);



	priv->slave = NULL;



	return 0;

}



static struct i2c_algorithm em_i2c_algo = {

	.master_xfer = em_i2c_xfer,

	.functionality = em_i2c_func,

	.reg_slave      = em_i2c_reg_slave,

	.unreg_slave    = em_i2c_unreg_slave,

};



static int em_i2c_probe(struct platform_device *pdev)