[RFC PATCH 2/3] mfd: syscon: Support early initialization
Michal Simek
michal.simek at xilinx.com
Mon Feb 10 10:22:34 EST 2014
Some platforms need to get system controller
ready as soon as possible.
The patch provides early_syscon_initialization
which create early mapping for all syscon compatible
devices in early_syscon_probe.
Regmap is get via syscon_early_regmap_lookup_by_phandle()
Regular device probes attach device to regmap
via regmap_attach_dev().
For early syscon initialization is necessary to extend
struct syscon and provide remove function
which unmap all early init structures.
Signed-off-by: Michal Simek <michal.simek at xilinx.com>
---
drivers/mfd/syscon.c | 126 +++++++++++++++++++++++++++++++++++++++------
include/linux/mfd/syscon.h | 11 ++++
2 files changed, 120 insertions(+), 17 deletions(-)
diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c
index 71841f9..5935f02 100644
--- a/drivers/mfd/syscon.c
+++ b/drivers/mfd/syscon.c
@@ -20,12 +20,15 @@
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
+#include <linux/slab.h>
#include <linux/mfd/syscon.h>
static struct platform_driver syscon_driver;
struct syscon {
+ void __iomem *base;
struct regmap *regmap;
+ struct resource res;
};
static int syscon_match_node(struct device *dev, void *data)
@@ -95,6 +98,24 @@ struct regmap *syscon_regmap_lookup_by_pdevname(const char *s)
}
EXPORT_SYMBOL_GPL(syscon_regmap_lookup_by_pdevname);
+struct regmap *syscon_early_regmap_lookup_by_phandle(struct device_node *np,
+ const char *property)
+{
+ struct device_node *syscon_np;
+ struct syscon *syscon;
+
+ syscon_np = of_parse_phandle(np, property, 0);
+ if (!syscon_np)
+ return ERR_PTR(-ENODEV);
+
+ syscon = syscon_np->data;
+
+ of_node_put(syscon_np);
+
+ return syscon->regmap;
+}
+EXPORT_SYMBOL_GPL(syscon_early_regmap_lookup_by_phandle);
+
struct regmap *syscon_regmap_lookup_by_phandle(struct device_node *np,
const char *property)
{
@@ -128,40 +149,110 @@ static int syscon_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
struct syscon *syscon;
struct resource *res;
- void __iomem *base;
- syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
+ /* Early syscon init */
+ if (pdev->dev.of_node && pdev->dev.of_node->data) {
+ syscon = pdev->dev.of_node->data;
+ res = &syscon->res;
+ regmap_attach_dev(dev, syscon->regmap, &syscon_regmap_config);
+ } else {
+
+ syscon = devm_kzalloc(dev, sizeof(*syscon), GFP_KERNEL);
+ if (!syscon)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res)
+ return -ENOENT;
+
+ syscon->base = devm_ioremap(dev, res->start,
+ resource_size(res));
+ if (!syscon->base)
+ return -ENOMEM;
+
+ syscon_regmap_config.max_register = res->end - res->start - 3;
+ syscon->regmap = devm_regmap_init_mmio(dev, syscon->base,
+ &syscon_regmap_config);
+ if (IS_ERR(syscon->regmap)) {
+ dev_err(dev, "regmap init failed\n");
+ return PTR_ERR(syscon->regmap);
+ }
+ }
+
+ platform_set_drvdata(pdev, syscon);
+
+ dev_info(dev, "regmap %pR registered\n", res);
+
+ return 0;
+}
+
+static const struct platform_device_id syscon_ids[] = {
+ { "syscon", },
+ { }
+};
+
+static int syscon_remove(struct platform_device *pdev)
+{
+ struct syscon *syscon = platform_get_drvdata(pdev);
+
+ if (pdev->dev.of_node && pdev->dev.of_node->data) {
+ iounmap(syscon->base);
+ kfree(syscon);
+ }
+
+ return 0;
+}
+
+static int early_syscon_probe(struct device_node *np)
+{
+ struct syscon *syscon;
+
+ syscon = kzalloc(sizeof(*syscon), GFP_KERNEL);
if (!syscon)
return -ENOMEM;
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!res)
- return -ENOENT;
+ if (of_address_to_resource(np, 0, &syscon->res))
+ return -EINVAL;
- base = devm_ioremap(dev, res->start, resource_size(res));
- if (!base)
- return -ENOMEM;
+ syscon->base = ioremap(syscon->res.start, resource_size(&syscon->res));
+ if (!syscon->base) {
+ pr_err("%s: Unable to map I/O memory\n", __func__);
+ return PTR_ERR(syscon->base);
+ }
- syscon_regmap_config.max_register = res->end - res->start - 3;
- syscon->regmap = devm_regmap_init_mmio(dev, base,
- &syscon_regmap_config);
+ syscon_regmap_config.max_register = syscon->res.end -
+ syscon->res.start - 3;
+ syscon->regmap = regmap_init_mmio(NULL, syscon->base,
+ &syscon_regmap_config);
if (IS_ERR(syscon->regmap)) {
- dev_err(dev, "regmap init failed\n");
+ pr_err("regmap init failed\n");
return PTR_ERR(syscon->regmap);
}
- platform_set_drvdata(pdev, syscon);
+ np->data = syscon;
- dev_info(dev, "regmap %pR registered\n", res);
+ of_node_put(np);
+
+ pr_info("%s: regmap %pR registered\n", np->full_name, &syscon->res);
return 0;
}
-static const struct platform_device_id syscon_ids[] = {
- { "syscon", },
- { }
+static struct of_device_id of_syscon_ids[] = {
+ { .compatible = "syscon" },
+ {},
};
+void __init early_syscon_init(void)
+{
+ struct device_node *np;
+
+ for_each_matching_node_and_match(np, of_syscon_ids, NULL) {
+ if (!early_syscon_probe(np))
+ BUG();
+ }
+}
+
static struct platform_driver syscon_driver = {
.driver = {
.name = "syscon",
@@ -169,6 +260,7 @@ static struct platform_driver syscon_driver = {
.of_match_table = of_syscon_match,
},
.probe = syscon_probe,
+ .remove = syscon_remove,
.id_table = syscon_ids,
};
diff --git a/include/linux/mfd/syscon.h b/include/linux/mfd/syscon.h
index 8789fa3..465c092 100644
--- a/include/linux/mfd/syscon.h
+++ b/include/linux/mfd/syscon.h
@@ -24,6 +24,10 @@ extern struct regmap *syscon_regmap_lookup_by_pdevname(const char *s);
extern struct regmap *syscon_regmap_lookup_by_phandle(
struct device_node *np,
const char *property);
+extern struct regmap *syscon_early_regmap_lookup_by_phandle(
+ struct device_node *np,
+ const char *property);
+extern void early_syscon_init(void);
#else
static inline struct regmap *syscon_node_to_regmap(struct device_node *np)
{
@@ -46,6 +50,13 @@ static inline struct regmap *syscon_regmap_lookup_by_phandle(
{
return ERR_PTR(-ENOSYS);
}
+
+static struct regmap *syscon_early_regmap_lookup_by_phandle(
+ struct device_node *np,
+ const char *property)
+{
+ return ERR_PTR(-ENOSYS);
+}
#endif
#endif /* __LINUX_MFD_SYSCON_H__ */
--
1.8.2.3
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 198 bytes
Desc: not available
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20140210/b29e2420/attachment-0001.sig>
More information about the linux-arm-kernel
mailing list