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authorLinus Torvalds <torvalds@linux-foundation.org>2016-07-28 00:19:25 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-07-28 00:19:25 +0300
commit66304207cd341045df34195b4a8d422075bff513 (patch)
tree14c51758f26f9f1b040a17acfe57e820b231fe3a /drivers/i2c/i2c-core.c
parent7ae0ae4a022b72f33d23ab6e858163d4b37400a5 (diff)
parent175c7080f2747b96e4b5352e4c38ddf9a0eacfdb (diff)
downloadlinux-66304207cd341045df34195b4a8d422075bff513.tar.xz
Merge branch 'i2c/for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang: "Here is the I2C pull request for 4.8: - the core and i801 driver gained support for SMBus Host Notify - core support for more than one address in DT - i2c_add_adapter() has now better error messages. We can remove all error messages from drivers calling it as a next step. - bigger updates to rk3x driver to support rk3399 SoC - the at24 eeprom driver got refactored and can now read special variants with unique serials or fixed MAC addresses. The rest is regular driver updates and bugfixes" * 'i2c/for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (66 commits) i2c: i801: use IS_ENABLED() instead of checking for built-in or module Documentation: i2c: slave: give proper example for pm usage Documentation: i2c: slave: describe buffer problems a bit better i2c: bcm2835: Don't complain on -EPROBE_DEFER from getting our clock i2c: i2c-smbus: drop useless stubs i2c: efm32: fix a failure path in efm32_i2c_probe() Revert "i2c: core: Cleanup I2C ACPI namespace" Revert "i2c: core: Add function for finding the bus speed from ACPI" i2c: Update the description of I2C_SMBUS i2c: i2c-smbus: fix i2c_handle_smbus_host_notify documentation eeprom: at24: tweak the loop_until_timeout() macro eeprom: at24: add support for at24mac series eeprom: at24: support reading the serial number for 24csxx eeprom: at24: platform_data: use BIT() macro eeprom: at24: split at24_eeprom_write() into specialized functions eeprom: at24: split at24_eeprom_read() into specialized functions eeprom: at24: hide the read/write loop behind a macro eeprom: at24: call read/write functions via function pointers eeprom: at24: coding style fixes eeprom: at24: move at24_read() below at24_eeprom_write() ...
Diffstat (limited to 'drivers/i2c/i2c-core.c')
-rw-r--r--drivers/i2c/i2c-core.c165
1 files changed, 107 insertions, 58 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 74e5aeaf84f9..da3a02ef4a31 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -27,6 +27,8 @@
I2C slave support (c) 2014 by Wolfram Sang <wsa@sang-engineering.com>
*/
+#define pr_fmt(fmt) "i2c-core: " fmt
+
#include <dt-bindings/i2c/i2c.h>
#include <asm/uaccess.h>
#include <linux/acpi.h>
@@ -493,7 +495,8 @@ acpi_i2c_space_handler(u32 function, acpi_physical_address command,
break;
default:
- pr_info("protocol(0x%02x) is not supported.\n", accessor_type);
+ dev_warn(&adapter->dev, "protocol 0x%02x not supported for client 0x%02x\n",
+ accessor_type, client->addr);
ret = AE_BAD_PARAMETER;
goto err;
}
@@ -759,6 +762,47 @@ int i2c_recover_bus(struct i2c_adapter *adap)
}
EXPORT_SYMBOL_GPL(i2c_recover_bus);
+static void i2c_init_recovery(struct i2c_adapter *adap)
+{
+ struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
+ char *err_str;
+
+ if (!bri)
+ return;
+
+ if (!bri->recover_bus) {
+ err_str = "no recover_bus() found";
+ goto err;
+ }
+
+ /* Generic GPIO recovery */
+ if (bri->recover_bus == i2c_generic_gpio_recovery) {
+ if (!gpio_is_valid(bri->scl_gpio)) {
+ err_str = "invalid SCL gpio";
+ goto err;
+ }
+
+ if (gpio_is_valid(bri->sda_gpio))
+ bri->get_sda = get_sda_gpio_value;
+ else
+ bri->get_sda = NULL;
+
+ bri->get_scl = get_scl_gpio_value;
+ bri->set_scl = set_scl_gpio_value;
+ } else if (bri->recover_bus == i2c_generic_scl_recovery) {
+ /* Generic SCL recovery */
+ if (!bri->set_scl || !bri->get_scl) {
+ err_str = "no {get|set}_scl() found";
+ goto err;
+ }
+ }
+
+ return;
+ err:
+ dev_err(&adap->dev, "Not using recovery: %s\n", err_str);
+ adap->bus_recovery_info = NULL;
+}
+
static int i2c_device_probe(struct device *dev)
{
struct i2c_client *client = i2c_verify_client(dev);
@@ -1240,6 +1284,47 @@ struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address)
}
EXPORT_SYMBOL_GPL(i2c_new_dummy);
+/**
+ * i2c_new_secondary_device - Helper to get the instantiated secondary address
+ * and create the associated device
+ * @client: Handle to the primary client
+ * @name: Handle to specify which secondary address to get
+ * @default_addr: Used as a fallback if no secondary address was specified
+ * Context: can sleep
+ *
+ * I2C clients can be composed of multiple I2C slaves bound together in a single
+ * component. The I2C client driver then binds to the master I2C slave and needs
+ * to create I2C dummy clients to communicate with all the other slaves.
+ *
+ * This function creates and returns an I2C dummy client whose I2C address is
+ * retrieved from the platform firmware based on the given slave name. If no
+ * address is specified by the firmware default_addr is used.
+ *
+ * On DT-based platforms the address is retrieved from the "reg" property entry
+ * cell whose "reg-names" value matches the slave name.
+ *
+ * This returns the new i2c client, which should be saved for later use with
+ * i2c_unregister_device(); or NULL to indicate an error.
+ */
+struct i2c_client *i2c_new_secondary_device(struct i2c_client *client,
+ const char *name,
+ u16 default_addr)
+{
+ struct device_node *np = client->dev.of_node;
+ u32 addr = default_addr;
+ int i;
+
+ if (np) {
+ i = of_property_match_string(np, "reg-names", name);
+ if (i >= 0)
+ of_property_read_u32_index(np, "reg", i, &addr);
+ }
+
+ dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr);
+ return i2c_new_dummy(client->adapter, addr);
+}
+EXPORT_SYMBOL_GPL(i2c_new_secondary_device);
+
/* ------------------------------------------------------------------------- */
/* I2C bus adapters -- one roots each I2C or SMBUS segment */
@@ -1608,7 +1693,7 @@ static int __process_new_adapter(struct device_driver *d, void *data)
static int i2c_register_adapter(struct i2c_adapter *adap)
{
- int res = 0;
+ int res = -EINVAL;
/* Can't register until after driver model init */
if (WARN_ON(!is_registered)) {
@@ -1617,15 +1702,12 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
}
/* Sanity checks */
- if (unlikely(adap->name[0] == '\0')) {
- pr_err("i2c-core: Attempt to register an adapter with "
- "no name!\n");
- return -EINVAL;
- }
- if (unlikely(!adap->algo)) {
- pr_err("i2c-core: Attempt to register adapter '%s' with "
- "no algo!\n", adap->name);
- return -EINVAL;
+ if (WARN(!adap->name[0], "i2c adapter has no name"))
+ goto out_list;
+
+ if (!adap->algo) {
+ pr_err("adapter '%s': no algo supplied!\n", adap->name);
+ goto out_list;
}
if (!adap->lock_bus) {
@@ -1647,8 +1729,10 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
adap->dev.bus = &i2c_bus_type;
adap->dev.type = &i2c_adapter_type;
res = device_register(&adap->dev);
- if (res)
+ if (res) {
+ pr_err("adapter '%s': can't register device (%d)\n", adap->name, res);
goto out_list;
+ }
dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
@@ -1664,41 +1748,8 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
"Failed to create compatibility class link\n");
#endif
- /* bus recovery specific initialization */
- if (adap->bus_recovery_info) {
- struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
-
- if (!bri->recover_bus) {
- dev_err(&adap->dev, "No recover_bus() found, not using recovery\n");
- adap->bus_recovery_info = NULL;
- goto exit_recovery;
- }
-
- /* Generic GPIO recovery */
- if (bri->recover_bus == i2c_generic_gpio_recovery) {
- if (!gpio_is_valid(bri->scl_gpio)) {
- dev_err(&adap->dev, "Invalid SCL gpio, not using recovery\n");
- adap->bus_recovery_info = NULL;
- goto exit_recovery;
- }
+ i2c_init_recovery(adap);
- if (gpio_is_valid(bri->sda_gpio))
- bri->get_sda = get_sda_gpio_value;
- else
- bri->get_sda = NULL;
-
- bri->get_scl = get_scl_gpio_value;
- bri->set_scl = set_scl_gpio_value;
- } else if (bri->recover_bus == i2c_generic_scl_recovery) {
- /* Generic SCL recovery */
- if (!bri->set_scl || !bri->get_scl) {
- dev_err(&adap->dev, "No {get|set}_scl() found, not using recovery\n");
- adap->bus_recovery_info = NULL;
- }
- }
- }
-
-exit_recovery:
/* create pre-declared device nodes */
of_i2c_register_devices(adap);
acpi_i2c_register_devices(adap);
@@ -1730,13 +1781,12 @@ out_list:
*/
static int __i2c_add_numbered_adapter(struct i2c_adapter *adap)
{
- int id;
+ int id;
mutex_lock(&core_lock);
- id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1,
- GFP_KERNEL);
+ id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL);
mutex_unlock(&core_lock);
- if (id < 0)
+ if (WARN(id < 0, "couldn't get idr"))
return id == -ENOSPC ? -EBUSY : id;
return i2c_register_adapter(adap);
@@ -1773,7 +1823,7 @@ int i2c_add_adapter(struct i2c_adapter *adapter)
id = idr_alloc(&i2c_adapter_idr, adapter,
__i2c_first_dynamic_bus_num, 0, GFP_KERNEL);
mutex_unlock(&core_lock);
- if (id < 0)
+ if (WARN(id < 0, "couldn't get idr"))
return id;
adapter->nr = id;
@@ -1871,8 +1921,7 @@ void i2c_del_adapter(struct i2c_adapter *adap)
found = idr_find(&i2c_adapter_idr, adap->nr);
mutex_unlock(&core_lock);
if (found != adap) {
- pr_debug("i2c-core: attempting to delete unregistered "
- "adapter [%s]\n", adap->name);
+ pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name);
return;
}
@@ -2032,7 +2081,7 @@ int i2c_register_driver(struct module *owner, struct i2c_driver *driver)
if (res)
return res;
- pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name);
+ pr_debug("driver [%s] registered\n", driver->driver.name);
INIT_LIST_HEAD(&driver->clients);
/* Walk the adapters that are already present */
@@ -2059,7 +2108,7 @@ void i2c_del_driver(struct i2c_driver *driver)
i2c_for_each_dev(driver, __process_removed_driver);
driver_unregister(&driver->driver);
- pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name);
+ pr_debug("driver [%s] unregistered\n", driver->driver.name);
}
EXPORT_SYMBOL(i2c_del_driver);
@@ -2150,8 +2199,8 @@ static int of_i2c_notify(struct notifier_block *nb, unsigned long action,
put_device(&adap->dev);
if (IS_ERR(client)) {
- pr_err("%s: failed to create for '%s'\n",
- __func__, rd->dn->full_name);
+ dev_err(&adap->dev, "failed to create client for '%s'\n",
+ rd->dn->full_name);
return notifier_from_errno(PTR_ERR(client));
}
break;
@@ -2772,7 +2821,7 @@ static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg)
cpec = i2c_smbus_msg_pec(cpec, msg);
if (rpec != cpec) {
- pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n",
+ pr_debug("Bad PEC 0x%02x vs. 0x%02x\n",
rpec, cpec);
return -EBADMSG;
}