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authorLinus Torvalds <torvalds@linux-foundation.org>2016-01-14 22:25:37 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-01-14 22:25:37 +0300
commit32250e4a5fa0b618044afa59fba01093a4bcb14a (patch)
tree678461393befc77b25e8d68cb637529927d3c284 /drivers/i2c/i2c-core.c
parent5339f9d4c2ceccab00b28d65bd5c2b2cd6a3de05 (diff)
parentc698d639f72b55686ec3518d2bc8dc5f2eca9354 (diff)
downloadlinux-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.c56
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 *))