diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-01-14 22:25:37 +0300 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-01-14 22:25:37 +0300 |
commit | 32250e4a5fa0b618044afa59fba01093a4bcb14a (patch) | |
tree | 678461393befc77b25e8d68cb637529927d3c284 /drivers/i2c/i2c-core.c | |
parent | 5339f9d4c2ceccab00b28d65bd5c2b2cd6a3de05 (diff) | |
parent | c698d639f72b55686ec3518d2bc8dc5f2eca9354 (diff) | |
download | linux-32250e4a5fa0b618044afa59fba01093a4bcb14a.tar.xz |
Merge branch 'i2c/for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c updates from Wolfram Sang:
"Quite some driver updates:
- piix4 can now handle multiplexed adapters
- brcmstb, xlr, eg20t, designware drivers support more SoCs
- emev2 gained i2c slave support
- img-scb and rcar got bigger refactoring to remove issues
- lots of common driver updates
i2c core changes:
- new quirk flag when an adapter does not support clock stretching,
so clients can be configured to avoid that if possible
- added a helper function to retrieve timing parameters from firmware
(with rcar being the first user)
- "multi-master" DT binding added so drivers can adapt to this
setting (like disabling PM to keep arbitration working)
- RuntimePM for the logical adapter device is now always enabled by
the core to ensure propagation from childs to the parent (the HW
device)
- new macro builtin_i2c_driver to reduce boilerplate"
* 'i2c/for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (70 commits)
i2c: create builtin_i2c_driver to avoid registration boilerplate
i2c: imx: fix i2c resource leak with dma transfer
dt-bindings: i2c: eeprom: add another EEPROM device
dt-bindings: move I2C eeprom descriptions to the proper file
i2c: designware: Do not require clock when SSCN and FFCN are provided
DT: i2c: trivial-devices: Add Epson RX8010 and MPL3115
i2c: s3c2410: remove superfluous runtime PM calls
i2c: always enable RuntimePM for the adapter device
i2c: designware: retry transfer on transient failure
i2c: ibm_iic: rename i2c_timings struct due to clash with generic version
i2c: designware: Add support for AMD Seattle I2C
i2c: imx: Remove unneeded comments
i2c: st: use to_platform_device()
i2c: designware: use to_pci_dev()
i2c: brcmstb: Adding support for CM and DSL SoCs
i2c: mediatek: fix i2c multi transfer issue in high speed mode
i2c: imx: improve code readability
i2c: imx: Improve message log when DMA is not used
i2c: imx: add runtime pm support to improve the performance
i2c: imx: init bus recovery info before adding i2c adapter
...
Diffstat (limited to 'drivers/i2c/i2c-core.c')
-rw-r--r-- | drivers/i2c/i2c-core.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index ba8eb087f224..ffe715d346d8 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -53,6 +53,7 @@ #include <linux/jump_label.h> #include <asm/uaccess.h> #include <linux/err.h> +#include <linux/property.h> #include "i2c-core.h" @@ -1563,6 +1564,7 @@ static int i2c_register_adapter(struct i2c_adapter *adap) dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); pm_runtime_no_callbacks(&adap->dev); + pm_runtime_enable(&adap->dev); #ifdef CONFIG_I2C_COMPAT res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, @@ -1817,6 +1819,8 @@ void i2c_del_adapter(struct i2c_adapter *adap) /* device name is gone after device_unregister */ dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); + pm_runtime_disable(&adap->dev); + /* wait until all references to the device are gone * * FIXME: This is old code and should ideally be replaced by an @@ -1839,6 +1843,58 @@ void i2c_del_adapter(struct i2c_adapter *adap) } EXPORT_SYMBOL(i2c_del_adapter); +/** + * i2c_parse_fw_timings - get I2C related timing parameters from firmware + * @dev: The device to scan for I2C timing properties + * @t: the i2c_timings struct to be filled with values + * @use_defaults: bool to use sane defaults derived from the I2C specification + * when properties are not found, otherwise use 0 + * + * Scan the device for the generic I2C properties describing timing parameters + * for the signal and fill the given struct with the results. If a property was + * not found and use_defaults was true, then maximum timings are assumed which + * are derived from the I2C specification. If use_defaults is not used, the + * results will be 0, so drivers can apply their own defaults later. The latter + * is mainly intended for avoiding regressions of existing drivers which want + * to switch to this function. New drivers almost always should use the defaults. + */ + +void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults) +{ + int ret; + + memset(t, 0, sizeof(*t)); + + ret = device_property_read_u32(dev, "clock-frequency", &t->bus_freq_hz); + if (ret && use_defaults) + t->bus_freq_hz = 100000; + + ret = device_property_read_u32(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns); + if (ret && use_defaults) { + if (t->bus_freq_hz <= 100000) + t->scl_rise_ns = 1000; + else if (t->bus_freq_hz <= 400000) + t->scl_rise_ns = 300; + else + t->scl_rise_ns = 120; + } + + ret = device_property_read_u32(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns); + if (ret && use_defaults) { + if (t->bus_freq_hz <= 400000) + t->scl_fall_ns = 300; + else + t->scl_fall_ns = 120; + } + + device_property_read_u32(dev, "i2c-scl-internal-delay-ns", &t->scl_int_delay_ns); + + ret = device_property_read_u32(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns); + if (ret && use_defaults) + t->sda_fall_ns = t->scl_fall_ns; +} +EXPORT_SYMBOL_GPL(i2c_parse_fw_timings); + /* ------------------------------------------------------------------------- */ int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)) |