Am Dienstag, den 06.01.2015, 20:36 +0100 schrieb Arnd Bergmann:
> On Tuesday 06 January 2015 16:30:36 Philipp Zabel wrote:
> > Patch bdb0066df96e ("mfd: syscon: Decouple syscon interface from platform
> > devices")
> > breaks probing pure syscon devices from device tree, such as anatop and
> > iomuxc-gpr on i.MX. This patch adds back the dt id table to match against
> > "syscon" compatible device tree nodes.
> >
> > Signed-off-by: Philipp Zabel <p.za...@pengutronix.de>
> >
>
> I don't understand it. Why is this required?
The debugfs entries vanished and I'd like to have a device to register
platform device children to. I guess for i.MX iomuxc it could be argued
that the iomuxc-gpr syscon should be merged into the iomuxc pinctrl
device instead of probing iomuxc-gpr as a platform device by itself.
How about allowing to register a syscon for a given device:
----8<----
diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
index d2280d6..2633b27 100644
--- a/drivers/mfd/syscon.c
+++ b/drivers/mfd/syscon.c
@@ -42,13 +42,14 @@ static struct regmap_config syscon_regmap_config = {
.reg_stride = 4,
};
-static struct syscon *of_syscon_register(struct device_node *np)
+struct syscon *syscon_register(struct device *dev, struct device_node *np)
{
struct syscon *syscon;
struct regmap *regmap;
void __iomem *base;
int ret;
struct regmap_config syscon_config = syscon_regmap_config;
+ struct resource res;
if (!of_device_is_compatible(np, "syscon"))
return ERR_PTR(-EINVAL);
@@ -57,7 +58,12 @@ static struct syscon *of_syscon_register(struct device_node
*np)
if (!syscon)
return ERR_PTR(-ENOMEM);
- base = of_iomap(np, 0);
+ if (of_address_to_resource(np, 0, &res)) {
+ ret = -ENOMEM;
+ goto err_map;
+ }
+
+ base = ioremap(res.start, resource_size(&res));
if (!base) {
ret = -ENOMEM;
goto err_map;
@@ -69,7 +75,8 @@ static struct syscon *of_syscon_register(struct device_node
*np)
else if (of_property_read_bool(np, "little-endian"))
syscon_config.val_format_endian = REGMAP_ENDIAN_LITTLE;
- regmap = regmap_init_mmio(NULL, base, &syscon_config);
+ syscon_regmap_config.max_register = res.end - res.start - 3;
+ regmap = regmap_init_mmio(dev, base, &syscon_config);
if (IS_ERR(regmap)) {
pr_err("regmap init failed\n");
ret = PTR_ERR(regmap);
@@ -91,6 +98,12 @@ err_map:
kfree(syscon);
return ERR_PTR(ret);
}
+EXPORT_SYMBOL_GPL(syscon_register);
+
+static struct syscon *of_syscon_register(struct device_node *np)
+{
+ return syscon_register(NULL, np);
+}
struct regmap *syscon_node_to_regmap(struct device_node *np)
{
diff --git a/include/linux/mfd/syscon.h b/include/linux/mfd/syscon.h
index 75e543b..e0c4a86 100644
--- a/include/linux/mfd/syscon.h
+++ b/include/linux/mfd/syscon.h
@@ -17,10 +17,14 @@
#include <linux/err.h>
+struct device;
struct device_node;
+struct syscon;
#ifdef CONFIG_MFD_SYSCON
extern struct regmap *syscon_node_to_regmap(struct device_node *np);
+extern struct syscon *syscon_register(struct device *dev,
+ struct device_node *np);
extern struct regmap *syscon_regmap_lookup_by_compatible(const char *s);
extern struct regmap *syscon_regmap_lookup_by_pdevname(const char *s);
extern struct regmap *syscon_regmap_lookup_by_phandle(
@@ -32,6 +36,12 @@ static inline struct regmap *syscon_node_to_regmap(struct
device_node *np)
return ERR_PTR(-ENOSYS);
}
+static struct syscon *syscon_register(struct device *dev,
+ struct device_node *np)
+{
+ return ERR_PTR(-ENOSYS);
+}
+
static inline struct regmap *syscon_regmap_lookup_by_compatible(const char *s)
{
return ERR_PTR(-ENOSYS);
--
---->8----
That way the syscon could be registered from iomuxc (pinctrl-imx6q):
----8<----
diff --git a/drivers/pinctrl/freescale/pinctrl-imx6q.c
b/drivers/pinctrl/freescale/pinctrl-imx6q.c
index 4d1fcb8..74a68ec 100644
--- a/drivers/pinctrl/freescale/pinctrl-imx6q.c
+++ b/drivers/pinctrl/freescale/pinctrl-imx6q.c
@@ -15,6 +15,7 @@
#include <linux/err.h>
#include <linux/init.h>
#include <linux/io.h>
+#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
@@ -473,6 +474,12 @@ static const struct of_device_id imx6q_pinctrl_of_match[]
= {
static int imx6q_pinctrl_probe(struct platform_device *pdev)
{
+ struct device_node *syscon_np;
+
+ syscon_np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-iomuxc-gpr");
+ if (syscon_np)
+ syscon_register(&pdev->dev, syscon_np);
+
return imx_pinctrl_probe(pdev, &imx6q_pinctrl_info);
}
---->8----
which makes the regmap debugfs entry return
as /sys/kernel/debug/regmap/20e0000.iomuxc
and allows to register children to the iomuxc-gpr node.
regards
Philipp
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
