Hi Lee,
I'm just trying to use this for my sl28 driver. Some remarks, see below.
Am 2020-06-22 09:51, schrieb Lee Jones:
The existing SYSCON implementation only supports MMIO (memory mapped)
accesses, facilitated by Regmap. This extends support for registers
held behind I2C busses.
Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
---
Changelog:
v3 => v4
- Add ability to provide a non-default Regmap configuration
v2 => v3
- Change 'is CONFIG' present check to include loadable modules
- s/#ifdef CONFIG_MFD_SYSCON_I2C/#if
IS_ENABLED(CONFIG_MFD_SYSCON_I2C)/
v1 => v2
- Remove legacy references to OF
- Allow building as a module (fixes h8300 0-day issue)
drivers/mfd/Kconfig | 7 +++
drivers/mfd/Makefile | 1 +
drivers/mfd/syscon-i2c.c | 104 +++++++++++++++++++++++++++++++++
include/linux/mfd/syscon-i2c.h | 36 ++++++++++++
4 files changed, 148 insertions(+)
create mode 100644 drivers/mfd/syscon-i2c.c
create mode 100644 include/linux/mfd/syscon-i2c.h
[..]
+static struct regmap *syscon_i2c_get_regmap(struct i2c_client *client,
+ struct regmap_config *regmap_config)
+{
+ struct device *dev = &client->dev;
+ struct syscon *entry, *syscon = NULL;
+
+ spin_lock(&syscon_i2c_list_slock);
+
+ list_for_each_entry(entry, &syscon_i2c_list, list)
+ if (entry->dev == dev) {
+ syscon = entry;
+ break;
+ }
+
+ spin_unlock(&syscon_i2c_list_slock);
+
+ if (!syscon)
+ syscon = syscon_i2c_register(client, regmap_config);
+
+ if (IS_ERR(syscon))
+ return ERR_CAST(syscon);
+
+ return syscon->regmap;
+}
+
+struct regmap *syscon_i2c_to_regmap_config(struct i2c_client *client,
+ struct regmap_config *regmap_config)
+{
+ return syscon_i2c_get_regmap(client, regmap_config);
+}
+EXPORT_SYMBOL_GPL(syscon_i2c_to_regmap_config);
+
+struct regmap *syscon_i2c_to_regmap(struct i2c_client *client)
+{
+ return syscon_i2c_get_regmap(client, &syscon_i2c_regmap_config);
+}
+EXPORT_SYMBOL_GPL(syscon_i2c_to_regmap);
What do you think about
struct regmap *syscon_i2c_to_regmap(struct device *dev)
{
struct i2c_client *client = i2c_verify_client(dev);
if (!client)
return ERR_PTR(-EINVAL);
return syscon_i2c_get_regmap(client, &syscon_i2c_regmap_config);
}
Or even move it to syscon_i2c_get_regmap().
This way, (a) a driver doesn't have to use "#include <linux/i2c.h>" just
to call to_i2c_client() (or i2c_verify_client()) and (b) you won't do it
all over again in all sub drivers.
So you could just do a
regmap = syscon_i2c_to_regmap(pdev->dev.parent);
I've also noticed that the mmio syscon uses device_node as parameter.
What
was the reason to divert from that? Just curious.
-michael
