diff options
Diffstat (limited to 'drivers/i2c/i2c-smbus.c')
| -rw-r--r-- | drivers/i2c/i2c-smbus.c | 109 |
1 files changed, 83 insertions, 26 deletions
diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c index 97f338b123b1..7d40e7aa3799 100644 --- a/drivers/i2c/i2c-smbus.c +++ b/drivers/i2c/i2c-smbus.c @@ -8,6 +8,7 @@ #include <linux/device.h> #include <linux/dmi.h> +#include <linux/gpio/consumer.h> #include <linux/i2c.h> #include <linux/i2c-smbus.h> #include <linux/interrupt.h> @@ -34,6 +35,7 @@ static int smbus_do_alert(struct device *dev, void *addrp) struct i2c_client *client = i2c_verify_client(dev); struct alert_data *data = addrp; struct i2c_driver *driver; + int ret; if (!client || client->addr != data->addr) return 0; @@ -47,16 +49,47 @@ static int smbus_do_alert(struct device *dev, void *addrp) device_lock(dev); if (client->dev.driver) { driver = to_i2c_driver(client->dev.driver); - if (driver->alert) + if (driver->alert) { + /* Stop iterating after we find the device */ driver->alert(client, data->type, data->data); - else + ret = -EBUSY; + } else { dev_warn(&client->dev, "no driver alert()!\n"); - } else + ret = -EOPNOTSUPP; + } + } else { dev_dbg(&client->dev, "alert with no driver\n"); + ret = -ENODEV; + } device_unlock(dev); - /* Stop iterating after we find the device */ - return -EBUSY; + return ret; +} + +/* Same as above, but call back all drivers with alert handler */ + +static int smbus_do_alert_force(struct device *dev, void *addrp) +{ + struct i2c_client *client = i2c_verify_client(dev); + struct alert_data *data = addrp; + struct i2c_driver *driver; + + if (!client || (client->flags & I2C_CLIENT_TEN)) + return 0; + + /* + * Drivers should either disable alerts, or provide at least + * a minimal handler. Lock so the driver won't change. + */ + device_lock(dev); + if (client->dev.driver) { + driver = to_i2c_driver(client->dev.driver); + if (driver->alert) + driver->alert(client, data->type, data->data); + } + device_unlock(dev); + + return 0; } /* @@ -67,6 +100,7 @@ static irqreturn_t smbus_alert(int irq, void *d) { struct i2c_smbus_alert *alert = d; struct i2c_client *ara; + unsigned short prev_addr = I2C_CLIENT_END; /* Not a valid address */ ara = alert->ara; @@ -94,8 +128,25 @@ static irqreturn_t smbus_alert(int irq, void *d) data.addr, data.data); /* Notify driver for the device which issued the alert */ - device_for_each_child(&ara->adapter->dev, &data, - smbus_do_alert); + status = device_for_each_child(&ara->adapter->dev, &data, + smbus_do_alert); + /* + * If we read the same address more than once, and the alert + * was not handled by a driver, it won't do any good to repeat + * the loop because it will never terminate. Try again, this + * time calling the alert handlers of all devices connected to + * the bus, and abort the loop afterwards. If this helps, we + * are all set. If it doesn't, there is nothing else we can do, + * so we might as well abort the loop. + * Note: This assumes that a driver with alert handler handles + * the alert properly and clears it if necessary. + */ + if (data.addr == prev_addr && status != -EBUSY) { + device_for_each_child(&ara->adapter->dev, &data, + smbus_do_alert_force); + break; + } + prev_addr = data.addr; } return IRQ_HANDLED; @@ -117,6 +168,8 @@ static int smbalert_probe(struct i2c_client *ara) struct i2c_smbus_alert_setup *setup = dev_get_platdata(&ara->dev); struct i2c_smbus_alert *alert; struct i2c_adapter *adapter = ara->adapter; + unsigned long irqflags = IRQF_SHARED | IRQF_ONESHOT; + struct gpio_desc *gpiod; int res, irq; alert = devm_kzalloc(&ara->dev, sizeof(struct i2c_smbus_alert), @@ -129,18 +182,25 @@ static int smbalert_probe(struct i2c_client *ara) } else { irq = fwnode_irq_get_byname(dev_fwnode(adapter->dev.parent), "smbus_alert"); - if (irq <= 0) - return irq; + if (irq <= 0) { + gpiod = devm_gpiod_get(adapter->dev.parent, "smbalert", GPIOD_IN); + if (IS_ERR(gpiod)) + return PTR_ERR(gpiod); + + irq = gpiod_to_irq(gpiod); + if (irq <= 0) + return irq; + + irqflags |= IRQF_TRIGGER_FALLING; + } } INIT_WORK(&alert->alert, smbalert_work); alert->ara = ara; if (irq > 0) { - res = devm_request_threaded_irq(&ara->dev, irq, - NULL, smbus_alert, - IRQF_SHARED | IRQF_ONESHOT, - "smbus_alert", alert); + res = devm_request_threaded_irq(&ara->dev, irq, NULL, smbus_alert, + irqflags, "smbus_alert", alert); if (res) return res; } @@ -160,7 +220,7 @@ static void smbalert_remove(struct i2c_client *ara) } static const struct i2c_device_id smbalert_ids[] = { - { "smbus_alert", 0 }, + { "smbus_alert" }, { /* LIST END */ } }; MODULE_DEVICE_TABLE(i2c, smbalert_ids); @@ -308,7 +368,7 @@ EXPORT_SYMBOL_GPL(i2c_free_slave_host_notify_device); * target systems are the same. * Restrictions to automatic SPD instantiation: * - Only works if all filled slots have the same memory type - * - Only works for DDR, DDR2, DDR3 and DDR4 for now + * - Only works for (LP)DDR memory types up to DDR5 * - Only works on systems with 1 to 8 memory slots */ #if IS_ENABLED(CONFIG_DMI) @@ -352,18 +412,11 @@ void i2c_register_spd(struct i2c_adapter *adap) return; /* - * If we're a child adapter on a muxed segment, then limit slots to 8, - * as this is the max number of SPD EEPROMs that can be addressed per bus. + * The max number of SPD EEPROMs that can be addressed per bus is 8. + * If more slots are present either muxed or multiple busses are + * necessary or the additional slots are ignored. */ - if (i2c_parent_is_i2c_adapter(adap)) { - slot_count = 8; - } else { - if (slot_count > 8) { - dev_warn(&adap->dev, - "More than 8 memory slots on a single bus, contact i801 maintainer to add missing mux config\n"); - return; - } - } + slot_count = min(slot_count, 8); /* * Memory types could be found at section 7.18.2 (Memory Device — Type), table 78 @@ -382,6 +435,10 @@ void i2c_register_spd(struct i2c_adapter *adap) case 0x1E: /* LPDDR4 */ name = "ee1004"; break; + case 0x22: /* DDR5 */ + case 0x23: /* LPDDR5 */ + name = "spd5118"; + break; default: dev_info(&adap->dev, "Memory type 0x%02x not supported yet, not instantiating SPD\n", |