* [RFC v2 2/3] i2c: Kconfig: rename variable I2C_SMBUS to I2C_SMBUS_ALERT
2017-11-28 3:38 [RFC v2 0/3] i2c: core: move smbus_alert into i2c-core Phil Reid
2017-11-28 3:38 ` [RFC v2 1/3] i2c: smbus: move of_i2c_setup_smbus_alert declaration to i2c-core.h Phil Reid
@ 2017-11-28 3:38 ` Phil Reid
2017-11-28 22:08 ` Jean Delvare
2017-11-28 3:38 ` [RFC v2 3/3] i2c: core: move smbus_alert module into i2c-core Phil Reid
2 siblings, 1 reply; 8+ messages in thread
From: Phil Reid @ 2017-11-28 3:38 UTC (permalink / raw)
To: realmz6, wsa, sre, preid, adi-buildroot-devel, linux-i2c,
linux-pm, jdelvare, benjamin.tissoires
i2c-smbus now only contains code related to the smbus_alert driver.
Other smbus protocols have been moved from this into the i2c-core-smbus.
Change the Kconfig variable name to reflect this.
Signed-off-by: Phil Reid <preid@electromag.com.au>
---
arch/blackfin/configs/BF527-TLL6527M_defconfig | 2 +-
drivers/i2c/Kconfig | 11 +++++------
drivers/i2c/Makefile | 2 +-
drivers/i2c/busses/Kconfig | 8 ++++----
drivers/i2c/i2c-core-smbus.c | 2 +-
drivers/i2c/i2c-core.h | 2 +-
drivers/power/supply/Kconfig | 2 +-
7 files changed, 14 insertions(+), 15 deletions(-)
diff --git a/arch/blackfin/configs/BF527-TLL6527M_defconfig b/arch/blackfin/configs/BF527-TLL6527M_defconfig
index cdeb518..30f3b5c 100644
--- a/arch/blackfin/configs/BF527-TLL6527M_defconfig
+++ b/arch/blackfin/configs/BF527-TLL6527M_defconfig
@@ -109,7 +109,7 @@ CONFIG_SERIAL_BFIN_UART1=y
# CONFIG_HW_RANDOM is not set
CONFIG_I2C_CHARDEV=y
# CONFIG_I2C_HELPER_AUTO is not set
-CONFIG_I2C_SMBUS=y
+CONFIG_I2C_SMBUS_ALERT=y
CONFIG_I2C_BLACKFIN_TWI=y
CONFIG_I2C_BLACKFIN_TWI_CLK_KHZ=100
CONFIG_GPIOLIB=y
diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
index efc3354..fcd4bea 100644
--- a/drivers/i2c/Kconfig
+++ b/drivers/i2c/Kconfig
@@ -55,7 +55,7 @@ config I2C_CHARDEV
programs use the I2C bus. Information on how to do this is
contained in the file <file:Documentation/i2c/dev-interface>.
- This support is also available as a module. If so, the module
+ This support is also available as a module. If so, the module
will be called i2c-dev.
config I2C_MUX
@@ -84,12 +84,11 @@ config I2C_HELPER_AUTO
In doubt, say Y.
-config I2C_SMBUS
- tristate "SMBus-specific protocols" if !I2C_HELPER_AUTO
+config I2C_SMBUS_ALERT
+ tristate "SMBus-alert protocol" if !I2C_HELPER_AUTO
help
- Say Y here if you want support for SMBus extensions to the I2C
- specification. At the moment, two extensions are supported:
- the SMBus Alert protocol and the SMBus Host Notify protocol.
+ Say Y here if you want support for SMBus alert extensions to the I2C
+ specification.
This support is also available as a module. If so, the module
will be called i2c-smbus.
diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
index 7bb65a4..b0116a1 100644
--- a/drivers/i2c/Makefile
+++ b/drivers/i2c/Makefile
@@ -9,7 +9,7 @@ i2c-core-$(CONFIG_ACPI) += i2c-core-acpi.o
i2c-core-$(CONFIG_I2C_SLAVE) += i2c-core-slave.o
i2c-core-$(CONFIG_OF) += i2c-core-of.o
-obj-$(CONFIG_I2C_SMBUS) += i2c-smbus.o
+obj-$(CONFIG_I2C_SMBUS_ALERT) += i2c-smbus.o
obj-$(CONFIG_I2C_CHARDEV) += i2c-dev.o
obj-$(CONFIG_I2C_MUX) += i2c-mux.o
obj-y += algos/ busses/ muxes/
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 009345d..310d5ec 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -91,7 +91,7 @@ config I2C_I801
tristate "Intel 82801 (ICH/PCH)"
depends on PCI
select CHECK_SIGNATURE if X86 && DMI
- select I2C_SMBUS
+ select I2C_SMBUS_ALERT
help
If you say yes to this option, support will be included for the Intel
801 family of mainboard I2C interfaces. Specifically, the following
@@ -1056,7 +1056,7 @@ config I2C_OCTEON
config I2C_THUNDERX
tristate "Cavium ThunderX I2C bus support"
depends on 64BIT && PCI && (ARM64 || COMPILE_TEST)
- select I2C_SMBUS
+ select I2C_SMBUS_ALERT
help
Say yes if you want to support the I2C serial bus on Cavium
ThunderX SOC.
@@ -1132,7 +1132,7 @@ config I2C_PARPORT
tristate "Parallel port adapter"
depends on PARPORT
select I2C_ALGOBIT
- select I2C_SMBUS
+ select I2C_SMBUS_ALERT
help
This supports parallel port I2C adapters such as the ones made by
Philips or Velleman, Analog Devices evaluation boards, and more.
@@ -1156,7 +1156,7 @@ config I2C_PARPORT
config I2C_PARPORT_LIGHT
tristate "Parallel port adapter (light)"
select I2C_ALGOBIT
- select I2C_SMBUS
+ select I2C_SMBUS_ALERT
help
This supports parallel port I2C adapters such as the ones made by
Philips or Velleman, Analog Devices evaluation boards, and more.
diff --git a/drivers/i2c/i2c-core-smbus.c b/drivers/i2c/i2c-core-smbus.c
index 4bb9927..f4c3b18 100644
--- a/drivers/i2c/i2c-core-smbus.c
+++ b/drivers/i2c/i2c-core-smbus.c
@@ -626,7 +626,7 @@ struct i2c_client *i2c_setup_smbus_alert(struct i2c_adapter *adapter,
}
EXPORT_SYMBOL_GPL(i2c_setup_smbus_alert);
-#if IS_ENABLED(CONFIG_I2C_SMBUS) && IS_ENABLED(CONFIG_OF)
+#if IS_ENABLED(CONFIG_I2C_SMBUS_ALERT) && IS_ENABLED(CONFIG_OF)
int of_i2c_setup_smbus_alert(struct i2c_adapter *adapter)
{
struct i2c_client *client;
diff --git a/drivers/i2c/i2c-core.h b/drivers/i2c/i2c-core.h
index 8ef0402..2ee5396 100644
--- a/drivers/i2c/i2c-core.h
+++ b/drivers/i2c/i2c-core.h
@@ -61,7 +61,7 @@ static inline void of_i2c_register_devices(struct i2c_adapter *adap) { }
#endif
extern struct notifier_block i2c_of_notifier;
-#if IS_ENABLED(CONFIG_I2C_SMBUS) && IS_ENABLED(CONFIG_OF)
+#if IS_ENABLED(CONFIG_I2C_SMBUS_ALERT) && IS_ENABLED(CONFIG_OF)
int of_i2c_setup_smbus_alert(struct i2c_adapter *adap);
#else
static inline int of_i2c_setup_smbus_alert(struct i2c_adapter *adap)
diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index fbca0ba..fac8252 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -187,7 +187,7 @@ config CHARGER_SBS
config MANAGER_SBS
tristate "Smart Battery System Manager"
depends on I2C && I2C_MUX && GPIOLIB
- select I2C_SMBUS
+ select I2C_SMBUS_ALERT
help
Say Y here to include support for Smart Battery System Manager
ICs. The driver reports online and charging status via sysfs.
--
1.8.3.1
^ permalink raw reply related [flat|nested] 8+ messages in thread* [RFC v2 3/3] i2c: core: move smbus_alert module into i2c-core
2017-11-28 3:38 [RFC v2 0/3] i2c: core: move smbus_alert into i2c-core Phil Reid
2017-11-28 3:38 ` [RFC v2 1/3] i2c: smbus: move of_i2c_setup_smbus_alert declaration to i2c-core.h Phil Reid
2017-11-28 3:38 ` [RFC v2 2/3] i2c: Kconfig: rename variable I2C_SMBUS to I2C_SMBUS_ALERT Phil Reid
@ 2017-11-28 3:38 ` Phil Reid
2 siblings, 0 replies; 8+ messages in thread
From: Phil Reid @ 2017-11-28 3:38 UTC (permalink / raw)
To: realmz6, wsa, sre, preid, adi-buildroot-devel, linux-i2c,
linux-pm, jdelvare, benjamin.tissoires
Remove the i2c-smbus module and move the smbus_alert driver into the
i2c-core. This simplifies the build logic for when i2c-core is builtin
and drivers selecting I2C_SMBUS_ALERT are modules. Also smbus_alert code
is moved from i2c-core-smbus.c to i2c-core-smbus-alert.c
Signed-off-by: Phil Reid <preid@electromag.com.au>
---
drivers/i2c/Kconfig | 5 +-
drivers/i2c/Makefile | 2 +-
drivers/i2c/i2c-core-base.c | 7 ++
drivers/i2c/i2c-core-smbus-alert.c | 243 +++++++++++++++++++++++++++++++++++++
drivers/i2c/i2c-core-smbus.c | 22 ----
drivers/i2c/i2c-core.h | 13 ++
drivers/i2c/i2c-smbus.c | 218 ---------------------------------
7 files changed, 265 insertions(+), 245 deletions(-)
create mode 100644 drivers/i2c/i2c-core-smbus-alert.c
delete mode 100644 drivers/i2c/i2c-smbus.c
diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
index fcd4bea..486a1f4 100644
--- a/drivers/i2c/Kconfig
+++ b/drivers/i2c/Kconfig
@@ -85,14 +85,11 @@ config I2C_HELPER_AUTO
In doubt, say Y.
config I2C_SMBUS_ALERT
- tristate "SMBus-alert protocol" if !I2C_HELPER_AUTO
+ bool "SMBus-alert protocol" if !I2C_HELPER_AUTO
help
Say Y here if you want support for SMBus alert extensions to the I2C
specification.
- This support is also available as a module. If so, the module
- will be called i2c-smbus.
-
source drivers/i2c/algos/Kconfig
source drivers/i2c/busses/Kconfig
diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
index b0116a1..efc3c54c 100644
--- a/drivers/i2c/Makefile
+++ b/drivers/i2c/Makefile
@@ -8,8 +8,8 @@ i2c-core-objs := i2c-core-base.o i2c-core-smbus.o
i2c-core-$(CONFIG_ACPI) += i2c-core-acpi.o
i2c-core-$(CONFIG_I2C_SLAVE) += i2c-core-slave.o
i2c-core-$(CONFIG_OF) += i2c-core-of.o
+i2c-core-$(CONFIG_I2C_SMBUS_ALERT) += i2c-core-smbus-alert.o
-obj-$(CONFIG_I2C_SMBUS_ALERT) += i2c-smbus.o
obj-$(CONFIG_I2C_CHARDEV) += i2c-dev.o
obj-$(CONFIG_I2C_MUX) += i2c-mux.o
obj-y += algos/ busses/ muxes/
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 54ffc8d..5788c80 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1690,6 +1690,10 @@ static int __init i2c_init(void)
if (retval)
goto class_err;
+ retval = i2c_smbus_alert_add_driver();
+ if (retval)
+ goto dummy_err;
+
if (IS_ENABLED(CONFIG_OF_DYNAMIC))
WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier));
if (IS_ENABLED(CONFIG_ACPI))
@@ -1697,6 +1701,8 @@ static int __init i2c_init(void)
return 0;
+dummy_err:
+ i2c_del_driver(&dummy_driver);
class_err:
#ifdef CONFIG_I2C_COMPAT
class_compat_unregister(i2c_adapter_compat_class);
@@ -1713,6 +1719,7 @@ static void __exit i2c_exit(void)
WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier));
if (IS_ENABLED(CONFIG_OF_DYNAMIC))
WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier));
+ i2c_smbus_alert_del_driver();
i2c_del_driver(&dummy_driver);
#ifdef CONFIG_I2C_COMPAT
class_compat_unregister(i2c_adapter_compat_class);
diff --git a/drivers/i2c/i2c-core-smbus-alert.c b/drivers/i2c/i2c-core-smbus-alert.c
new file mode 100644
index 0000000..fb5aae6
--- /dev/null
+++ b/drivers/i2c/i2c-core-smbus-alert.c
@@ -0,0 +1,243 @@
+/*
+ * i2c-smbus.c - SMBus extensions to the I2C protocol
+ *
+ * Copyright (C) 2008 David Brownell
+ * Copyright (C) 2010 Jean Delvare <jdelvare@suse.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_irq.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+#include "i2c-core.h"
+
+struct i2c_smbus_alert {
+ struct work_struct alert;
+ struct i2c_client *ara; /* Alert response address */
+};
+
+struct alert_data {
+ unsigned short addr;
+ enum i2c_alert_protocol type;
+ unsigned int data;
+};
+
+/* If this is the alerting device, notify its driver */
+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;
+
+ if (!client || client->addr != data->addr)
+ return 0;
+ if (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);
+ else
+ dev_warn(&client->dev, "no driver alert()!\n");
+ } else
+ dev_dbg(&client->dev, "alert with no driver\n");
+ device_unlock(dev);
+
+ /* Stop iterating after we find the device */
+ return -EBUSY;
+}
+
+/*
+ * The alert IRQ handler needs to hand work off to a task which can issue
+ * SMBus calls, because those sleeping calls can't be made in IRQ context.
+ */
+static irqreturn_t smbus_alert(int irq, void *d)
+{
+ struct i2c_smbus_alert *alert = d;
+ struct i2c_client *ara;
+ unsigned short prev_addr = 0; /* Not a valid address */
+
+ ara = alert->ara;
+
+ for (;;) {
+ s32 status;
+ struct alert_data data;
+
+ /*
+ * Devices with pending alerts reply in address order, low
+ * to high, because of slave transmit arbitration. After
+ * responding, an SMBus device stops asserting SMBALERT#.
+ *
+ * Note that SMBus 2.0 reserves 10-bit addresses for future
+ * use. We neither handle them, nor try to use PEC here.
+ */
+ status = i2c_smbus_read_byte(ara);
+ if (status < 0)
+ break;
+
+ data.data = status & 1;
+ data.addr = status >> 1;
+ data.type = I2C_PROTOCOL_SMBUS_ALERT;
+
+ if (data.addr == prev_addr) {
+ dev_warn(&ara->dev, "Duplicate SMBALERT# from dev "
+ "0x%02x, skipping\n", data.addr);
+ break;
+ }
+ dev_dbg(&ara->dev, "SMBALERT# from dev 0x%02x, flag %d\n",
+ data.addr, data.data);
+
+ /* Notify driver for the device which issued the alert */
+ device_for_each_child(&ara->adapter->dev, &data,
+ smbus_do_alert);
+ prev_addr = data.addr;
+ }
+
+ return IRQ_HANDLED;
+}
+
+static void smbalert_work(struct work_struct *work)
+{
+ struct i2c_smbus_alert *alert;
+
+ alert = container_of(work, struct i2c_smbus_alert, alert);
+
+ smbus_alert(0, alert);
+}
+
+/* Setup SMBALERT# infrastructure */
+static int smbalert_probe(struct i2c_client *ara,
+ const struct i2c_device_id *id)
+{
+ struct i2c_smbus_alert_setup *setup = dev_get_platdata(&ara->dev);
+ struct i2c_smbus_alert *alert;
+ struct i2c_adapter *adapter = ara->adapter;
+ int res, irq;
+
+ alert = devm_kzalloc(&ara->dev, sizeof(struct i2c_smbus_alert),
+ GFP_KERNEL);
+ if (!alert)
+ return -ENOMEM;
+
+ if (setup) {
+ irq = setup->irq;
+ } else {
+ irq = of_irq_get_byname(adapter->dev.of_node, "smbus_alert");
+ if (irq <= 0)
+ return irq;
+ }
+
+ 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);
+ if (res)
+ return res;
+ }
+
+ i2c_set_clientdata(ara, alert);
+ dev_info(&adapter->dev, "supports SMBALERT#\n");
+
+ return 0;
+}
+
+/* IRQ and memory resources are managed so they are freed automatically */
+static int smbalert_remove(struct i2c_client *ara)
+{
+ struct i2c_smbus_alert *alert = i2c_get_clientdata(ara);
+
+ cancel_work_sync(&alert->alert);
+ return 0;
+}
+
+static const struct i2c_device_id smbalert_ids[] = {
+ { "smbus_alert", 0 },
+ { /* LIST END */ }
+};
+MODULE_DEVICE_TABLE(i2c, smbalert_ids);
+
+static struct i2c_driver smbalert_driver = {
+ .driver = {
+ .name = "smbus_alert",
+ },
+ .probe = smbalert_probe,
+ .remove = smbalert_remove,
+ .id_table = smbalert_ids,
+};
+
+#if IS_ENABLED(CONFIG_OF)
+int of_i2c_setup_smbus_alert(struct i2c_adapter *adapter)
+{
+ struct i2c_client *client;
+ int irq;
+
+ irq = of_property_match_string(adapter->dev.of_node, "interrupt-names",
+ "smbus_alert");
+ if (irq == -EINVAL || irq == -ENODATA)
+ return 0;
+ else if (irq < 0)
+ return irq;
+
+ client = i2c_setup_smbus_alert(adapter, NULL);
+ if (!client)
+ return -ENODEV;
+
+ return 0;
+}
+#endif
+
+/**
+ * i2c_handle_smbus_alert - Handle an SMBus alert
+ * @ara: the ARA client on the relevant adapter
+ * Context: can't sleep
+ *
+ * Helper function to be called from an I2C bus driver's interrupt
+ * handler. It will schedule the alert work, in turn calling the
+ * corresponding I2C device driver's alert function.
+ *
+ * It is assumed that ara is a valid i2c client previously returned by
+ * i2c_setup_smbus_alert().
+ */
+int i2c_handle_smbus_alert(struct i2c_client *ara)
+{
+ struct i2c_smbus_alert *alert = i2c_get_clientdata(ara);
+
+ return schedule_work(&alert->alert);
+}
+EXPORT_SYMBOL_GPL(i2c_handle_smbus_alert);
+
+int i2c_smbus_alert_add_driver(void)
+{
+ return i2c_add_driver(&smbalert_driver);
+}
+
+void i2c_smbus_alert_del_driver(void)
+{
+ i2c_del_driver(&smbalert_driver);
+}
diff --git a/drivers/i2c/i2c-core-smbus.c b/drivers/i2c/i2c-core-smbus.c
index f4c3b18..7f3ec02 100644
--- a/drivers/i2c/i2c-core-smbus.c
+++ b/drivers/i2c/i2c-core-smbus.c
@@ -625,25 +625,3 @@ struct i2c_client *i2c_setup_smbus_alert(struct i2c_adapter *adapter,
return i2c_new_device(adapter, &ara_board_info);
}
EXPORT_SYMBOL_GPL(i2c_setup_smbus_alert);
-
-#if IS_ENABLED(CONFIG_I2C_SMBUS_ALERT) && IS_ENABLED(CONFIG_OF)
-int of_i2c_setup_smbus_alert(struct i2c_adapter *adapter)
-{
- struct i2c_client *client;
- int irq;
-
- irq = of_property_match_string(adapter->dev.of_node, "interrupt-names",
- "smbus_alert");
- if (irq == -EINVAL || irq == -ENODATA)
- return 0;
- else if (irq < 0)
- return irq;
-
- client = i2c_setup_smbus_alert(adapter, NULL);
- if (!client)
- return -ENODEV;
-
- return 0;
-}
-EXPORT_SYMBOL_GPL(of_i2c_setup_smbus_alert);
-#endif
diff --git a/drivers/i2c/i2c-core.h b/drivers/i2c/i2c-core.h
index 2ee5396..c6873f4 100644
--- a/drivers/i2c/i2c-core.h
+++ b/drivers/i2c/i2c-core.h
@@ -69,3 +69,16 @@ static inline int of_i2c_setup_smbus_alert(struct i2c_adapter *adap)
return 0;
}
#endif
+
+#if IS_ENABLED(CONFIG_I2C_SMBUS_ALERT)
+int i2c_smbus_alert_add_driver(void);
+void i2c_smbus_alert_del_driver(void);
+#else
+static inline int i2c_smbus_alert_add_driver(void)
+{
+ return 0;
+}
+static inline void i2c_smbus_alert_del_driver(void)
+{
+}
+#endif
diff --git a/drivers/i2c/i2c-smbus.c b/drivers/i2c/i2c-smbus.c
deleted file mode 100644
index c11a50e..0000000
--- a/drivers/i2c/i2c-smbus.c
+++ /dev/null
@@ -1,218 +0,0 @@
-/*
- * i2c-smbus.c - SMBus extensions to the I2C protocol
- *
- * Copyright (C) 2008 David Brownell
- * Copyright (C) 2010 Jean Delvare <jdelvare@suse.de>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- */
-
-#include <linux/device.h>
-#include <linux/i2c.h>
-#include <linux/i2c-smbus.h>
-#include <linux/interrupt.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/of_irq.h>
-#include <linux/slab.h>
-#include <linux/workqueue.h>
-
-#include "i2c-core.h"
-
-struct i2c_smbus_alert {
- struct work_struct alert;
- struct i2c_client *ara; /* Alert response address */
-};
-
-struct alert_data {
- unsigned short addr;
- enum i2c_alert_protocol type;
- unsigned int data;
-};
-
-/* If this is the alerting device, notify its driver */
-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;
-
- if (!client || client->addr != data->addr)
- return 0;
- if (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);
- else
- dev_warn(&client->dev, "no driver alert()!\n");
- } else
- dev_dbg(&client->dev, "alert with no driver\n");
- device_unlock(dev);
-
- /* Stop iterating after we find the device */
- return -EBUSY;
-}
-
-/*
- * The alert IRQ handler needs to hand work off to a task which can issue
- * SMBus calls, because those sleeping calls can't be made in IRQ context.
- */
-static irqreturn_t smbus_alert(int irq, void *d)
-{
- struct i2c_smbus_alert *alert = d;
- struct i2c_client *ara;
- unsigned short prev_addr = 0; /* Not a valid address */
-
- ara = alert->ara;
-
- for (;;) {
- s32 status;
- struct alert_data data;
-
- /*
- * Devices with pending alerts reply in address order, low
- * to high, because of slave transmit arbitration. After
- * responding, an SMBus device stops asserting SMBALERT#.
- *
- * Note that SMBus 2.0 reserves 10-bit addresses for future
- * use. We neither handle them, nor try to use PEC here.
- */
- status = i2c_smbus_read_byte(ara);
- if (status < 0)
- break;
-
- data.data = status & 1;
- data.addr = status >> 1;
- data.type = I2C_PROTOCOL_SMBUS_ALERT;
-
- if (data.addr == prev_addr) {
- dev_warn(&ara->dev, "Duplicate SMBALERT# from dev "
- "0x%02x, skipping\n", data.addr);
- break;
- }
- dev_dbg(&ara->dev, "SMBALERT# from dev 0x%02x, flag %d\n",
- data.addr, data.data);
-
- /* Notify driver for the device which issued the alert */
- device_for_each_child(&ara->adapter->dev, &data,
- smbus_do_alert);
- prev_addr = data.addr;
- }
-
- return IRQ_HANDLED;
-}
-
-static void smbalert_work(struct work_struct *work)
-{
- struct i2c_smbus_alert *alert;
-
- alert = container_of(work, struct i2c_smbus_alert, alert);
-
- smbus_alert(0, alert);
-}
-
-/* Setup SMBALERT# infrastructure */
-static int smbalert_probe(struct i2c_client *ara,
- const struct i2c_device_id *id)
-{
- struct i2c_smbus_alert_setup *setup = dev_get_platdata(&ara->dev);
- struct i2c_smbus_alert *alert;
- struct i2c_adapter *adapter = ara->adapter;
- int res, irq;
-
- alert = devm_kzalloc(&ara->dev, sizeof(struct i2c_smbus_alert),
- GFP_KERNEL);
- if (!alert)
- return -ENOMEM;
-
- if (setup) {
- irq = setup->irq;
- } else {
- irq = of_irq_get_byname(adapter->dev.of_node, "smbus_alert");
- if (irq <= 0)
- return irq;
- }
-
- 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);
- if (res)
- return res;
- }
-
- i2c_set_clientdata(ara, alert);
- dev_info(&adapter->dev, "supports SMBALERT#\n");
-
- return 0;
-}
-
-/* IRQ and memory resources are managed so they are freed automatically */
-static int smbalert_remove(struct i2c_client *ara)
-{
- struct i2c_smbus_alert *alert = i2c_get_clientdata(ara);
-
- cancel_work_sync(&alert->alert);
- return 0;
-}
-
-static const struct i2c_device_id smbalert_ids[] = {
- { "smbus_alert", 0 },
- { /* LIST END */ }
-};
-MODULE_DEVICE_TABLE(i2c, smbalert_ids);
-
-static struct i2c_driver smbalert_driver = {
- .driver = {
- .name = "smbus_alert",
- },
- .probe = smbalert_probe,
- .remove = smbalert_remove,
- .id_table = smbalert_ids,
-};
-
-/**
- * i2c_handle_smbus_alert - Handle an SMBus alert
- * @ara: the ARA client on the relevant adapter
- * Context: can't sleep
- *
- * Helper function to be called from an I2C bus driver's interrupt
- * handler. It will schedule the alert work, in turn calling the
- * corresponding I2C device driver's alert function.
- *
- * It is assumed that ara is a valid i2c client previously returned by
- * i2c_setup_smbus_alert().
- */
-int i2c_handle_smbus_alert(struct i2c_client *ara)
-{
- struct i2c_smbus_alert *alert = i2c_get_clientdata(ara);
-
- return schedule_work(&alert->alert);
-}
-EXPORT_SYMBOL_GPL(i2c_handle_smbus_alert);
-
-module_i2c_driver(smbalert_driver);
-
-MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
-MODULE_DESCRIPTION("SMBus protocol extensions support");
-MODULE_LICENSE("GPL");
--
1.8.3.1
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