"irq" and "wakeup" names are recognized by I2C core, other names are
left to individual drivers.
+- host-notify
+ device uses SMBus host notify protocol instead of interrupt line.
+
- multi-master
states that there is another master active on this bus. The OS can use
this information to adapt power management to keep the arbitration awake
used by the device. I2C core will assign "irq" interrupt (or the very first
interrupt if not using interrupt names) as primary interrupt for the slave.
+Alternatively, devices supporting SMbus Host Notify, and connected to
+adapters that support this feature, may use "host-notify" property. I2C
+core will create a virtual interrupt for Host Notify and assign it as
+primary interrupt for the slave.
+
Also, if device is marked as a wakeup source, I2C core will set up "wakeup"
interrupt for the device. If "wakeup" interrupt name is not present in the
binding, then primary interrupt will be used as wakeup interrupt.
u8 command, int size, union i2c_smbus_data *data)
{
struct i2c_piix4_adapdata *adapdata = i2c_get_adapdata(adap);
+ unsigned short piix4_smba = adapdata->smba;
+ int retries = MAX_TIMEOUT;
+ int smbslvcnt;
u8 smba_en_lo;
u8 port;
int retval;
+ /* Request the SMBUS semaphore, avoid conflicts with the IMC */
+ smbslvcnt = inb_p(SMBSLVCNT);
+ do {
+ outb_p(smbslvcnt | 0x10, SMBSLVCNT);
+
+ /* Check the semaphore status */
+ smbslvcnt = inb_p(SMBSLVCNT);
+ if (smbslvcnt & 0x10)
+ break;
+
+ usleep_range(1000, 2000);
+ } while (--retries);
+ /* SMBus is still owned by the IMC, we give up */
+ if (!retries)
+ return -EBUSY;
+
mutex_lock(&piix4_mutex_sb800);
outb_p(piix4_port_sel_sb800, SB800_PIIX4_SMB_IDX);
mutex_unlock(&piix4_mutex_sb800);
+ /* Release the semaphore */
+ outb_p(smbslvcnt | 0x20, SMBSLVCNT);
+
return retval;
}
if (!client->irq) {
int irq = -ENOENT;
- if (dev->of_node) {
+ if (client->flags & I2C_CLIENT_HOST_NOTIFY) {
+ dev_dbg(dev, "Using Host Notify IRQ\n");
+ irq = i2c_smbus_host_notify_to_irq(client);
+ } else if (dev->of_node) {
irq = of_irq_get_byname(dev->of_node, "irq");
if (irq == -EINVAL || irq == -ENODATA)
irq = of_irq_get(dev->of_node, 0);
}
if (irq == -EPROBE_DEFER)
return irq;
- /*
- * ACPI and OF did not find any useful IRQ, try to see
- * if Host Notify can be used.
- */
- if (irq < 0) {
- dev_dbg(dev, "Using Host Notify IRQ\n");
- irq = i2c_smbus_host_notify_to_irq(client);
- }
+
if (irq < 0)
irq = 0;
if (i2c_check_addr_validity(addr, info.flags)) {
dev_err(&adap->dev, "of_i2c: invalid addr=%x on %s\n",
- info.addr, node->full_name);
+ addr, node->full_name);
return ERR_PTR(-EINVAL);
}
info.of_node = of_node_get(node);
info.archdata = &dev_ad;
+ if (of_property_read_bool(node, "host-notify"))
+ info.flags |= I2C_CLIENT_HOST_NOTIFY;
+
if (of_get_property(node, "wakeup-source", NULL))
info.flags |= I2C_CLIENT_WAKE;
int ret;
if (!client || !slave_cb) {
- WARN(1, "insufficent data\n");
+ WARN(1, "insufficient data\n");
return -EINVAL;
}
unsigned long arg)
{
struct i2c_smbus_ioctl_data data_arg;
- union i2c_smbus_data temp;
+ union i2c_smbus_data temp = {};
int datasize, res;
if (copy_from_user(&data_arg,
#define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
/* Must equal I2C_M_TEN below */
#define I2C_CLIENT_SLAVE 0x20 /* we are the slave */
+#define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */
#define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
#define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */
/* Must match I2C_M_STOP|IGNORE_NAK */