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authorTony Lindgren <tony@atomide.com>2018-02-22 13:58:03 -0800
committerTony Lindgren <tony@atomide.com>2018-02-26 14:16:10 -0800
commit2c355ff6b6ca6e0153cc6845aa004b9f5212d81e (patch)
tree25d78419eddb76afc316193794ddc379b8395c90 /drivers/bus
parentd060b40523dcd91428c7fb2aaa307de37887484a (diff)
downloadlinux-2c355ff6b6ca6e0153cc6845aa004b9f5212d81e.tar.bz2
bus: ti-sysc: Add fck clock alias for children with notifier_block
The functional clock is used by several child device drivers to query the rate for the child device internal configuration. The functional clock is really for the whole interconnect target module, and not just for the child device, and can also be shared across multiple children. At least the timers, i2c and mmc driver query the fck for rate. So let's just create a clock alias for the child fck if it does not yet exits. We can do this with the BUS_NOTIFY_ADD_DEVICE before the child is probed. Note that we need to now also remove the legacy mode check for getting the dts clocks in ti-sysc driver. Signed-off-by: Tony Lindgren <tony@atomide.com>
Diffstat (limited to 'drivers/bus')
-rw-r--r--drivers/bus/ti-sysc.c91
1 files changed, 87 insertions, 4 deletions
diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c
index 4d46003c46cf..3ffe5446ff34 100644
--- a/drivers/bus/ti-sysc.c
+++ b/drivers/bus/ti-sysc.c
@@ -13,11 +13,14 @@
#include <linux/io.h>
#include <linux/clk.h>
+#include <linux/clkdev.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
+#include <linux/slab.h>
+
#include <linux/platform_data/ti-sysc.h>
#include <dt-bindings/bus/ti-sysc.h>
@@ -136,9 +139,6 @@ static int sysc_get_clocks(struct sysc *ddata)
{
int i, error;
- if (ddata->legacy_mode)
- return 0;
-
for (i = 0; i < SYSC_MAX_CLOCKS; i++) {
error = sysc_get_one_clock(ddata, i);
if (error && error != -ENOENT)
@@ -605,6 +605,74 @@ static int sysc_init_syss_mask(struct sysc *ddata)
return 0;
}
+/*
+ * Many child device drivers need to have fck available to get the clock
+ * rate for device internal configuration.
+ */
+static int sysc_child_add_fck(struct sysc *ddata,
+ struct device *child)
+{
+ struct clk *fck;
+ struct clk_lookup *l;
+ const char *name = clock_names[SYSC_FCK];
+
+ if (IS_ERR_OR_NULL(ddata->clocks[SYSC_FCK]))
+ return 0;
+
+ fck = clk_get(child, name);
+ if (!IS_ERR(fck)) {
+ clk_put(fck);
+
+ return -EEXIST;
+ }
+
+ l = clkdev_create(ddata->clocks[SYSC_FCK], name, dev_name(child));
+
+ return l ? 0 : -ENODEV;
+}
+
+static struct device_type sysc_device_type = {
+};
+
+static struct sysc *sysc_child_to_parent(struct device *dev)
+{
+ struct device *parent = dev->parent;
+
+ if (!parent || parent->type != &sysc_device_type)
+ return NULL;
+
+ return dev_get_drvdata(parent);
+}
+
+static int sysc_notifier_call(struct notifier_block *nb,
+ unsigned long event, void *device)
+{
+ struct device *dev = device;
+ struct sysc *ddata;
+ int error;
+
+ ddata = sysc_child_to_parent(dev);
+ if (!ddata)
+ return NOTIFY_DONE;
+
+ switch (event) {
+ case BUS_NOTIFY_ADD_DEVICE:
+ error = sysc_child_add_fck(ddata, dev);
+ if (error && error != -EEXIST)
+ dev_warn(ddata->dev, "could not add %s fck: %i\n",
+ dev_name(dev), error);
+ break;
+ default:
+ break;
+ }
+
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block sysc_nb = {
+ .notifier_call = sysc_notifier_call,
+};
+
/* Device tree configured quirks */
struct sysc_dts_quirk {
const char *name;
@@ -937,6 +1005,7 @@ static int sysc_probe(struct platform_device *pdev)
sysc_show_registers(ddata);
+ ddata->dev->type = &sysc_device_type;
error = of_platform_populate(ddata->dev->of_node,
NULL, NULL, ddata->dev);
if (error)
@@ -1008,7 +1077,21 @@ static struct platform_driver sysc_driver = {
.pm = &sysc_pm_ops,
},
};
-module_platform_driver(sysc_driver);
+
+static int __init sysc_init(void)
+{
+ bus_register_notifier(&platform_bus_type, &sysc_nb);
+
+ return platform_driver_register(&sysc_driver);
+}
+module_init(sysc_init);
+
+static void __exit sysc_exit(void)
+{
+ bus_unregister_notifier(&platform_bus_type, &sysc_nb);
+ platform_driver_unregister(&sysc_driver);
+}
+module_exit(sysc_exit);
MODULE_DESCRIPTION("TI sysc interconnect target driver");
MODULE_LICENSE("GPL v2");