diff options
| -rw-r--r-- | Documentation/i2c/smbus-protocol | 12 | ||||
| -rw-r--r-- | drivers/i2c/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/i2c/busses/i2c-i801.c | 32 | ||||
| -rw-r--r-- | drivers/i2c/i2c-core.c | 113 | ||||
| -rw-r--r-- | drivers/i2c/i2c-smbus.c | 102 | ||||
| -rw-r--r-- | include/linux/i2c-smbus.h | 27 | ||||
| -rw-r--r-- | include/linux/i2c.h | 4 |
7 files changed, 133 insertions, 158 deletions
diff --git a/Documentation/i2c/smbus-protocol b/Documentation/i2c/smbus-protocol index 14d4ec1be245..092d474f5843 100644 --- a/Documentation/i2c/smbus-protocol +++ b/Documentation/i2c/smbus-protocol @@ -200,10 +200,14 @@ alerting device's address. [S] [HostAddr] [Wr] A [DevAddr] A [DataLow] A [DataHigh] A [P] This is implemented in the following way in the Linux kernel: -* I2C bus drivers which support SMBus Host Notify should call - i2c_setup_smbus_host_notify() to setup SMBus Host Notify support. -* I2C drivers for devices which can trigger SMBus Host Notify should implement - the optional alert() callback. +* I2C bus drivers which support SMBus Host Notify should report + I2C_FUNC_SMBUS_HOST_NOTIFY. +* I2C bus drivers trigger SMBus Host Notify by a call to + i2c_handle_smbus_host_notify(). +* I2C drivers for devices which can trigger SMBus Host Notify will have + client->irq assigned to a Host Notify IRQ if noone else specified an other. + +There is currently no way to retrieve the data parameter from the client. Packet Error Checking (PEC) diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig index d223650a97e4..de305f89a659 100644 --- a/drivers/i2c/Kconfig +++ b/drivers/i2c/Kconfig @@ -7,6 +7,7 @@ menu "I2C support" config I2C tristate "I2C support" select RT_MUTEXES + select IRQ_DOMAIN ---help--- I2C (pronounce: I-squared-C) is a slow serial bus protocol used in many micro controller applications and developed by Philips. SMBus, diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index c0c0cac9950c..e242db43774b 100644 --- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -269,7 +269,6 @@ struct i801_priv { */ bool acpi_reserved; struct mutex acpi_lock; - struct smbus_host_notify *host_notify; }; #define FEATURE_SMBUS_PEC BIT(0) @@ -585,10 +584,10 @@ static irqreturn_t i801_host_notify_isr(struct i801_priv *priv) /* * With the tested platforms, reading SMBNTFDDAT (22 + (p)->smba) - * always returns 0 and is safe to read. - * We just use 0 given we have no use of the data right now. + * always returns 0. Our current implementation doesn't provide + * data, so we just ignore it. */ - i2c_handle_smbus_host_notify(priv->host_notify, addr, 0); + i2c_handle_smbus_host_notify(&priv->adapter, addr); /* clear Host Notify bit and return */ outb_p(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv)); @@ -951,17 +950,12 @@ static u32 i801_func(struct i2c_adapter *adapter) I2C_FUNC_SMBUS_HOST_NOTIFY : 0); } -static int i801_enable_host_notify(struct i2c_adapter *adapter) +static void i801_enable_host_notify(struct i2c_adapter *adapter) { struct i801_priv *priv = i2c_get_adapdata(adapter); if (!(priv->features & FEATURE_HOST_NOTIFY)) - return -ENOTSUPP; - - if (!priv->host_notify) - priv->host_notify = i2c_setup_smbus_host_notify(adapter); - if (!priv->host_notify) - return -ENOMEM; + return; priv->original_slvcmd = inb_p(SMBSLVCMD(priv)); @@ -971,8 +965,6 @@ static int i801_enable_host_notify(struct i2c_adapter *adapter) /* clear Host Notify bit to allow a new notification */ outb_p(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv)); - - return 0; } static void i801_disable_host_notify(struct i801_priv *priv) @@ -1647,14 +1639,7 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id) return err; } - /* - * Enable Host Notify for chips that supports it. - * It is done after i2c_add_adapter() so that we are sure the work queue - * is not used if i2c_add_adapter() fails. - */ - err = i801_enable_host_notify(&priv->adapter); - if (err && err != -ENOTSUPP) - dev_warn(&dev->dev, "Unable to enable SMBus Host Notify\n"); + i801_enable_host_notify(&priv->adapter); i801_probe_optional_slaves(priv); /* We ignore errors - multiplexing is optional */ @@ -1705,11 +1690,8 @@ static int i801_resume(struct device *dev) { struct pci_dev *pci_dev = to_pci_dev(dev); struct i801_priv *priv = pci_get_drvdata(pci_dev); - int err; - err = i801_enable_host_notify(&priv->adapter); - if (err && err != -ENOTSUPP) - dev_warn(dev, "Unable to enable SMBus Host Notify\n"); + i801_enable_host_notify(&priv->adapter); return 0; } diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 8b93a262e237..3a1bc9c4efc7 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -65,6 +65,9 @@ #define I2C_ADDR_OFFSET_TEN_BIT 0xa000 #define I2C_ADDR_OFFSET_SLAVE 0x1000 +#define I2C_ADDR_7BITS_MAX 0x77 +#define I2C_ADDR_7BITS_COUNT (I2C_ADDR_7BITS_MAX + 1) + /* core_lock protects i2c_adapter_idr, and guarantees that device detection, deletion of detected devices, and attach_adapter calls are serialized */ @@ -896,6 +899,25 @@ static void i2c_init_recovery(struct i2c_adapter *adap) adap->bus_recovery_info = NULL; } +static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client) +{ + struct i2c_adapter *adap = client->adapter; + unsigned int irq; + + if (!adap->host_notify_domain) + return -ENXIO; + + if (client->flags & I2C_CLIENT_TEN) + return -EINVAL; + + irq = irq_find_mapping(adap->host_notify_domain, client->addr); + if (!irq) + irq = irq_create_mapping(adap->host_notify_domain, + client->addr); + + return irq > 0 ? irq : -ENXIO; +} + static int i2c_device_probe(struct device *dev) { struct i2c_client *client = i2c_verify_client(dev); @@ -917,6 +939,14 @@ static int i2c_device_probe(struct device *dev) } 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; @@ -1866,6 +1896,79 @@ static const struct i2c_lock_operations i2c_adapter_lock_ops = { .unlock_bus = i2c_adapter_unlock_bus, }; +static void i2c_host_notify_irq_teardown(struct i2c_adapter *adap) +{ + struct irq_domain *domain = adap->host_notify_domain; + irq_hw_number_t hwirq; + + if (!domain) + return; + + for (hwirq = 0 ; hwirq < I2C_ADDR_7BITS_COUNT ; hwirq++) + irq_dispose_mapping(irq_find_mapping(domain, hwirq)); + + irq_domain_remove(domain); + adap->host_notify_domain = NULL; +} + +static int i2c_host_notify_irq_map(struct irq_domain *h, + unsigned int virq, + irq_hw_number_t hw_irq_num) +{ + irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq); + + return 0; +} + +static const struct irq_domain_ops i2c_host_notify_irq_ops = { + .map = i2c_host_notify_irq_map, +}; + +static int i2c_setup_host_notify_irq_domain(struct i2c_adapter *adap) +{ + struct irq_domain *domain; + + if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_HOST_NOTIFY)) + return 0; + + domain = irq_domain_create_linear(adap->dev.fwnode, + I2C_ADDR_7BITS_COUNT, + &i2c_host_notify_irq_ops, adap); + if (!domain) + return -ENOMEM; + + adap->host_notify_domain = domain; + + return 0; +} + +/** + * i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct + * I2C client. + * @adap: the adapter + * @addr: the I2C address of the notifying device + * Context: can't sleep + * + * Helper function to be called from an I2C bus driver's interrupt + * handler. It will schedule the Host Notify IRQ. + */ +int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr) +{ + int irq; + + if (!adap) + return -EINVAL; + + irq = irq_find_mapping(adap->host_notify_domain, addr); + if (irq <= 0) + return -ENXIO; + + generic_handle_irq(irq); + + return 0; +} +EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify); + static int i2c_register_adapter(struct i2c_adapter *adap) { int res = -EINVAL; @@ -1897,6 +2000,14 @@ static int i2c_register_adapter(struct i2c_adapter *adap) if (adap->timeout == 0) adap->timeout = HZ; + /* register soft irqs for Host Notify */ + res = i2c_setup_host_notify_irq_domain(adap); + if (res) { + pr_err("adapter '%s': can't create Host Notify IRQs (%d)\n", + adap->name, res); + goto out_list; + } + dev_set_name(&adap->dev, "i2c-%d", adap->nr); adap->dev.bus = &i2c_bus_type; adap->dev.type = &i2c_adapter_type; @@ -2134,6 +2245,8 @@ void i2c_del_adapter(struct i2c_adapter *adap) pm_runtime_disable(&adap->dev); + i2c_host_notify_irq_teardown(adap); + /* wait until all references to the device are gone * * FIXME: This is old code and should ideally be replaced by an diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c index b0d2679c60d1..f9271c713d20 100644 --- a/drivers/i2c/i2c-smbus.c +++ b/drivers/i2c/i2c-smbus.c @@ -241,108 +241,6 @@ int i2c_handle_smbus_alert(struct i2c_client *ara) } EXPORT_SYMBOL_GPL(i2c_handle_smbus_alert); -static void smbus_host_notify_work(struct work_struct *work) -{ - struct alert_data alert; - struct i2c_adapter *adapter; - unsigned long flags; - u16 payload; - u8 addr; - struct smbus_host_notify *data; - - data = container_of(work, struct smbus_host_notify, work); - - spin_lock_irqsave(&data->lock, flags); - payload = data->payload; - addr = data->addr; - adapter = data->adapter; - - /* clear the pending bit and release the spinlock */ - data->pending = false; - spin_unlock_irqrestore(&data->lock, flags); - - if (!adapter || !addr) - return; - - alert.type = I2C_PROTOCOL_SMBUS_HOST_NOTIFY; - alert.addr = addr; - alert.data = payload; - - device_for_each_child(&adapter->dev, &alert, smbus_do_alert); -} - -/** - * i2c_setup_smbus_host_notify - Allocate a new smbus_host_notify for the given - * I2C adapter. - * @adapter: the adapter we want to associate a Host Notify function - * - * Returns a struct smbus_host_notify pointer on success, and NULL on failure. - * The resulting smbus_host_notify must not be freed afterwards, it is a - * managed resource already. - */ -struct smbus_host_notify *i2c_setup_smbus_host_notify(struct i2c_adapter *adap) -{ - struct smbus_host_notify *host_notify; - - host_notify = devm_kzalloc(&adap->dev, sizeof(struct smbus_host_notify), - GFP_KERNEL); - if (!host_notify) - return NULL; - - host_notify->adapter = adap; - - spin_lock_init(&host_notify->lock); - INIT_WORK(&host_notify->work, smbus_host_notify_work); - - return host_notify; -} -EXPORT_SYMBOL_GPL(i2c_setup_smbus_host_notify); - -/** - * i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct - * I2C client. - * @host_notify: the struct host_notify attached to the relevant adapter - * @addr: the I2C address of the notifying device - * @data: the payload of the notification - * Context: can't sleep - * - * Helper function to be called from an I2C bus driver's interrupt - * handler. It will schedule the Host Notify work, in turn calling the - * corresponding I2C device driver's alert function. - * - * host_notify should be a valid pointer previously returned by - * i2c_setup_smbus_host_notify(). - */ -int i2c_handle_smbus_host_notify(struct smbus_host_notify *host_notify, - unsigned short addr, unsigned int data) -{ - unsigned long flags; - struct i2c_adapter *adapter; - - if (!host_notify || !host_notify->adapter) - return -EINVAL; - - adapter = host_notify->adapter; - - spin_lock_irqsave(&host_notify->lock, flags); - - if (host_notify->pending) { - spin_unlock_irqrestore(&host_notify->lock, flags); - dev_warn(&adapter->dev, "Host Notify already scheduled.\n"); - return -EBUSY; - } - - host_notify->payload = data; - host_notify->addr = addr; - - /* Mark that there is a pending notification and release the lock */ - host_notify->pending = true; - spin_unlock_irqrestore(&host_notify->lock, flags); - - return schedule_work(&host_notify->work); -} -EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify); - module_i2c_driver(smbalert_driver); MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>"); diff --git a/include/linux/i2c-smbus.h b/include/linux/i2c-smbus.h index c2e3324f9468..a1385023a29b 100644 --- a/include/linux/i2c-smbus.h +++ b/include/linux/i2c-smbus.h @@ -50,31 +50,4 @@ struct i2c_client *i2c_setup_smbus_alert(struct i2c_adapter *adapter, struct i2c_smbus_alert_setup *setup); int i2c_handle_smbus_alert(struct i2c_client *ara); -/** - * smbus_host_notify - internal structure used by the Host Notify mechanism. - * @adapter: the I2C adapter associated with this struct - * @work: worker used to schedule the IRQ in the slave device - * @lock: spinlock to check if a notification is already pending - * @pending: flag set when a notification is pending (any new notification will - * be rejected if pending is true) - * @payload: the actual payload of the Host Notify event - * @addr: the address of the slave device which raised the notification - * - * This struct needs to be allocated by i2c_setup_smbus_host_notify() and does - * not need to be freed. Internally, i2c_setup_smbus_host_notify() uses a - * managed resource to clean this up when the adapter get released. - */ -struct smbus_host_notify { - struct i2c_adapter *adapter; - struct work_struct work; - spinlock_t lock; - bool pending; - u16 payload; - u8 addr; -}; - -struct smbus_host_notify *i2c_setup_smbus_host_notify(struct i2c_adapter *adap); -int i2c_handle_smbus_host_notify(struct smbus_host_notify *host_notify, - unsigned short addr, unsigned int data); - #endif /* _LINUX_I2C_SMBUS_H */ diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 82cf90945bb8..b2109c522dec 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -30,6 +30,7 @@ #include <linux/device.h> /* for struct device */ #include <linux/sched.h> /* for completion */ #include <linux/mutex.h> +#include <linux/irqdomain.h> /* for Host Notify IRQ */ #include <linux/of.h> /* for struct device_node */ #include <linux/swab.h> /* for swab16 */ #include <uapi/linux/i2c.h> @@ -575,6 +576,8 @@ struct i2c_adapter { struct i2c_bus_recovery_info *bus_recovery_info; const struct i2c_adapter_quirks *quirks; + + struct irq_domain *host_notify_domain; }; #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) @@ -747,6 +750,7 @@ static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg) return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0); } +int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr); /** * module_i2c_driver() - Helper macro for registering a modular I2C driver * @__i2c_driver: i2c_driver struct |