[PATCH v3 2/2] OMAP: omap_device: Add a method to build an omap_device from a DT node
Benoit Cousson
b-cousson at ti.com
Thu Sep 22 16:52:25 EDT 2011
Add a notifier called during device_add phase. If an of_node is present,
retrieve the hwmod entry in order to populate properly the omap_device
structure.
For the moment the resource from the device-tree are overloaded.
DT does not support named resource yet, and thus, most driver
will not work without that information.
Add two helpers function to parse a property that contains multiple
strings. Please note that these helpers will be replaced by a more generic
iterator currently proposed on devicetree mailing list as soon as it
will be merged.
Add a documentation to capture the specifics OMAP bindings
needed for device-tree support.
Signed-off-by: Benoit Cousson <b-cousson at ti.com>
Cc: Kevin Hilman <khilman at ti.com>
---
.../devicetree/bindings/arm/omap/omap.txt | 42 ++++++
arch/arm/plat-omap/omap_device.c | 145 ++++++++++++++++++++
2 files changed, 187 insertions(+), 0 deletions(-)
create mode 100644 Documentation/devicetree/bindings/arm/omap/omap.txt
diff --git a/Documentation/devicetree/bindings/arm/omap/omap.txt b/Documentation/devicetree/bindings/arm/omap/omap.txt
new file mode 100644
index 0000000..6513d05
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/omap/omap.txt
@@ -0,0 +1,42 @@
+* Texas Instruments OMAP
+
+OMAP is currently using a static file per SoC family to describe the
+IPs present in the SoC.
+On top of that an omap_device is created to extend the platform_device
+capabilities and to allow binding with one or several hwmods.
+The hwmods will contain all the information to build the device:
+adresse range, irq lines, dma lines, interconnect, PRCM register,
+clock domain, input clocks.
+For the moment just point to the existing hwmod, the next step will be
+to move data from hwmod to device-tree representation.
+
+
+Required properties:
+- compatible: Every devices present in OMAP SoC should be in the
+ form: "ti,XXX"
+- ti,hwmods: list of hwmods attached to a device. Must contain at least
+ one hwmod.
+
+Optional properties:
+- ti,no_idle_on_suspend: When present, it prevents the PM to idle the module
+ during suspend.
+
+
+Example:
+
+spinlock at 1 {
+ compatible = "ti,omap-spinlock";
+ ti,hwmods = "spinlock";
+};
+
+
+Boards:
+
+- OMAP3 BeagleBoard : Low cost community board
+ compatible = "ti,omap3-beagle", "ti,omap3"
+
+- OMAP4 SDP : Software Developement Board
+ compatible = "ti,omap4-sdp", "ti,omap4430"
+
+- OMAP4 PandaBoard : Low cost community board
+ compatible = "ti,omap4-panda", "ti,omap4430"
diff --git a/arch/arm/plat-omap/omap_device.c b/arch/arm/plat-omap/omap_device.c
index cac7b9a..5b63989 100644
--- a/arch/arm/plat-omap/omap_device.c
+++ b/arch/arm/plat-omap/omap_device.c
@@ -85,6 +85,8 @@
#include <linux/clk.h>
#include <linux/clkdev.h>
#include <linux/pm_runtime.h>
+#include <linux/of.h>
+#include <linux/notifier.h>
#include <plat/omap_device.h>
#include <plat/omap_hwmod.h>
@@ -94,12 +96,15 @@
#define USE_WAKEUP_LAT 0
#define IGNORE_WAKEUP_LAT 1
+#define MAX_HWMOD_NAME_SIZE 32
+
static int omap_device_register(struct platform_device *pdev);
static int omap_early_device_register(struct platform_device *pdev);
static struct omap_device *omap_device_alloc(struct platform_device *pdev,
struct omap_hwmod **ohs, int oh_cnt,
struct omap_device_pm_latency *pm_lats,
int pm_lats_cnt);
+static void omap_device_delete(struct omap_device *od);
static struct omap_device_pm_latency omap_default_latency[] = {
@@ -315,6 +320,138 @@ static void _add_hwmod_clocks_clkdev(struct omap_device *od,
_add_clkdev(od, oh->opt_clks[i].role, oh->opt_clks[i].clk);
}
+/*
+ * XXX: DT helper functions that should be replaced by more generic
+ * API introduced by Stephen Warren once they'll be in mainline.
+ */
+static int _dt_count_property_string(const char *prop, int len)
+{
+ int i = 0;
+ size_t l = 0, total = 0;
+
+ if (!prop || !len)
+ return -EINVAL;
+
+ for (i = 0; len >= total; total += l, prop += l) {
+ l = strlen(prop) + 1;
+ if (*prop != 0)
+ i++;
+ }
+ return i;
+}
+
+static int _dt_get_property(const char *prop, int len, int index, char *output,
+ int size)
+{
+ int i = 0;
+ size_t l = 0, total = 0;
+
+ if (!prop || !len)
+ return -EINVAL;
+
+ for (i = 0; len >= total; total += l, prop += l) {
+ l = strlcpy(output, prop, size) + 1;
+ if (*prop != 0) {
+ if (i++ == index)
+ return 0;
+ }
+ }
+ return -ENODEV;
+}
+
+static struct dev_pm_domain omap_device_pm_domain;
+
+/**
+ * omap_device_build_from_dt - build an omap_device with multiple hwmods
+ * @pdev_name: name of the platform_device driver to use
+ * @pdev_id: this platform_device's connection ID
+ * @oh: ptr to the single omap_hwmod that backs this omap_device
+ * @pdata: platform_data ptr to associate with the platform_device
+ * @pdata_len: amount of memory pointed to by @pdata
+ * @pm_lats: pointer to a omap_device_pm_latency array for this device
+ * @pm_lats_cnt: ARRAY_SIZE() of @pm_lats
+ * @is_early_device: should the device be registered as an early device or not
+ *
+ * Function for building an omap_device already registered from device-tree
+ *
+ * Returns 0 or PTR_ERR() on error.
+ */
+static int omap_device_build_from_dt(struct platform_device *pdev)
+{
+ struct omap_hwmod **hwmods;
+ struct omap_device *od;
+ struct omap_hwmod *oh;
+ char oh_name[MAX_HWMOD_NAME_SIZE];
+ const char *prop;
+ int oh_cnt, i, prop_len;
+ int ret = 0;
+
+ prop = of_get_property(pdev->dev.of_node, "ti,hwmods", &prop_len);
+ oh_cnt = _dt_count_property_string(prop, prop_len);
+ if (!oh_cnt || IS_ERR_VALUE(oh_cnt)) {
+ dev_warn(&pdev->dev, "No 'hwmods' to build omap_device\n");
+ return -ENODEV;
+ }
+
+ hwmods = kzalloc(sizeof(struct omap_hwmod *) * oh_cnt, GFP_KERNEL);
+ if (!hwmods) {
+ ret = -ENOMEM;
+ goto odbfd_exit;
+ }
+
+ for (i = 0; i < oh_cnt; i++) {
+ _dt_get_property(prop, prop_len, i, oh_name,
+ MAX_HWMOD_NAME_SIZE);
+
+ oh = omap_hwmod_lookup(oh_name);
+ if (!oh) {
+ dev_err(&pdev->dev, "Cannot lookup hwmod '%s'\n",
+ oh_name);
+ ret = -EINVAL;
+ goto odbfd_exit1;
+ }
+ hwmods[i] = oh;
+ }
+
+ od = omap_device_alloc(pdev, hwmods, oh_cnt, NULL, 0);
+ if (!od) {
+ dev_err(&pdev->dev, "Cannot allocate omap_device for :%s\n",
+ oh_name);
+ ret = PTR_ERR(od);
+ goto odbfd_exit1;
+ }
+
+ if (of_get_property(pdev->dev.of_node, "ti,no_idle_on_suspend", NULL))
+ omap_device_disable_idle_on_suspend(pdev);
+
+ pdev->dev.pm_domain = &omap_device_pm_domain;
+
+odbfd_exit1:
+ kfree(hwmods);
+odbfd_exit:
+ return ret;
+}
+
+static int _omap_device_notifier_call(struct notifier_block *nb,
+ unsigned long event, void *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+
+ switch (event) {
+ case BUS_NOTIFY_ADD_DEVICE:
+ if (pdev->dev.of_node)
+ omap_device_build_from_dt(pdev);
+ break;
+
+ case BUS_NOTIFY_DEL_DEVICE:
+ if (pdev->archdata.od)
+ omap_device_delete(pdev->archdata.od);
+ break;
+ }
+
+ return NOTIFY_DONE;
+}
+
/* Public functions for use by core code */
@@ -499,6 +636,9 @@ oda_exit1:
static void omap_device_delete(struct omap_device *od)
{
+ if (!od)
+ return;
+
od->pdev->archdata.od = NULL;
kfree(od->pm_lats);
kfree(od->hwmods);
@@ -1034,8 +1174,13 @@ struct device omap_device_parent = {
.parent = &platform_bus,
};
+static struct notifier_block platform_nb = {
+ .notifier_call = _omap_device_notifier_call,
+};
+
static int __init omap_device_init(void)
{
+ bus_register_notifier(&platform_bus_type, &platform_nb);
return device_register(&omap_device_parent);
}
core_initcall(omap_device_init);
--
1.7.0.4
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