mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 19:29:37 +00:00
i2c: emev2: add slave support
Add I2C slave provider using the generic slave interface. Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
parent
7a852b02d4
commit
c31d0a0002
1 changed files with 111 additions and 1 deletions
|
@ -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)
|
||||
|
|
Loading…
Reference in a new issue