1 files changed, 341 insertions, 115 deletions

diff --git a/arch/arm/plat-omap/omap_device.c b/arch/arm/plat-omap/omap_device.c
index 9a6a53854911..e8d98693d2dd 100644
--- a/arch/arm/plat-omap/omap_device.c
+++ b/arch/arm/plat-omap/omap_device.c
@@ -78,6 +78,7 @@
 #undef DEBUG
 
 #include <linux/kernel.h>
+#include <linux/export.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/err.h>
@@ -85,6 +86,8 @@
 #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>
@@ -94,6 +97,23 @@
 #define USE_WAKEUP_LAT                  0
 #define IGNORE_WAKEUP_LAT               1
 
+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[] = {
+        {
+                .deactivate_func = omap_device_idle_hwmods,
+                .activate_func   = omap_device_enable_hwmods,
+                .flags = OMAP_DEVICE_LATENCY_AUTO_ADJUST,
+        }
+};
+
 /* Private functions */
 
 /**
@@ -114,7 +134,7 @@ static int _omap_device_activate(struct omap_device *od, u8 ignore_lat)
 {
         struct timespec a, b, c;
 
-        pr_debug("omap_device: %s: activating\n", od->pdev.name);
+        dev_dbg(&od->pdev->dev, "omap_device: activating\n");
 
         while (od->pm_lat_level > 0) {
                 struct omap_device_pm_latency *odpl;
@@ -138,25 +158,24 @@ static int _omap_device_activate(struct omap_device *od, u8 ignore_lat)
                 c = timespec_sub(b, a);
                 act_lat = timespec_to_ns(&c);
 
-                pr_debug("omap_device: %s: pm_lat %d: activate: elapsed time "
-                         "%llu nsec\n", od->pdev.name, od->pm_lat_level,
-                         act_lat);
+                dev_dbg(&od->pdev->dev,
+                        "omap_device: pm_lat %d: activate: elapsed time "
+                        "%llu nsec\n", od->pm_lat_level, act_lat);
 
                 if (act_lat > odpl->activate_lat) {
                         odpl->activate_lat_worst = act_lat;
                         if (odpl->flags & OMAP_DEVICE_LATENCY_AUTO_ADJUST) {
                                 odpl->activate_lat = act_lat;
-                                pr_warning("omap_device: %s.%d: new worst case "
-                                           "activate latency %d: %llu\n",
-                                           od->pdev.name, od->pdev.id,
-                                           od->pm_lat_level, act_lat);
+                                dev_dbg(&od->pdev->dev,
+                                        "new worst case activate latency "
+                                        "%d: %llu\n",
+                                        od->pm_lat_level, act_lat);
                         } else
-                                pr_warning("omap_device: %s.%d: activate "
-                                           "latency %d higher than exptected. "
-                                           "(%llu > %d)\n",
-                                           od->pdev.name, od->pdev.id,
-                                           od->pm_lat_level, act_lat,
-                                           odpl->activate_lat);
+                                dev_warn(&od->pdev->dev,
+                                         "activate latency %d "
+                                         "higher than exptected. (%llu > %d)\n",
+                                         od->pm_lat_level, act_lat,
+                                         odpl->activate_lat);
                 }
 
                 od->dev_wakeup_lat -= odpl->activate_lat;
@@ -183,7 +202,7 @@ static int _omap_device_deactivate(struct omap_device *od, u8 ignore_lat)
 {
         struct timespec a, b, c;
 
-        pr_debug("omap_device: %s: deactivating\n", od->pdev.name);
+        dev_dbg(&od->pdev->dev, "omap_device: deactivating\n");
 
         while (od->pm_lat_level < od->pm_lats_cnt) {
                 struct omap_device_pm_latency *odpl;
@@ -206,28 +225,26 @@ static int _omap_device_deactivate(struct omap_device *od, u8 ignore_lat)
                 c = timespec_sub(b, a);
                 deact_lat = timespec_to_ns(&c);
 
-                pr_debug("omap_device: %s: pm_lat %d: deactivate: elapsed time "
-                         "%llu nsec\n", od->pdev.name, od->pm_lat_level,
-                         deact_lat);
+                dev_dbg(&od->pdev->dev,
+                        "omap_device: pm_lat %d: deactivate: elapsed time "
+                        "%llu nsec\n", od->pm_lat_level, deact_lat);
 
                 if (deact_lat > odpl->deactivate_lat) {
                         odpl->deactivate_lat_worst = deact_lat;
                         if (odpl->flags & OMAP_DEVICE_LATENCY_AUTO_ADJUST) {
                                 odpl->deactivate_lat = deact_lat;
-                                pr_warning("omap_device: %s.%d: new worst case "
-                                           "deactivate latency %d: %llu\n",
-                                           od->pdev.name, od->pdev.id,
-                                           od->pm_lat_level, deact_lat);
+                                dev_dbg(&od->pdev->dev,
+                                        "new worst case deactivate latency "
+                                        "%d: %llu\n",
+                                        od->pm_lat_level, deact_lat);
                         } else
-                                pr_warning("omap_device: %s.%d: deactivate "
-                                           "latency %d higher than exptected. "
-                                           "(%llu > %d)\n",
-                                           od->pdev.name, od->pdev.id,
-                                           od->pm_lat_level, deact_lat,
-                                           odpl->deactivate_lat);
+                                dev_warn(&od->pdev->dev,
+                                         "deactivate latency %d "
+                                         "higher than exptected. (%llu > %d)\n",
+                                         od->pm_lat_level, deact_lat,
+                                         odpl->deactivate_lat);
                 }
 
-
                 od->dev_wakeup_lat += odpl->activate_lat;
 
                 od->pm_lat_level++;
@@ -245,28 +262,27 @@ static void _add_clkdev(struct omap_device *od, const char *clk_alias,
         if (!clk_alias || !clk_name)
                 return;
 
-        pr_debug("omap_device: %s: Creating %s -> %s\n",
-                 dev_name(&od->pdev.dev), clk_alias, clk_name);
+        dev_dbg(&od->pdev->dev, "Creating %s -> %s\n", clk_alias, clk_name);
 
-        r = clk_get_sys(dev_name(&od->pdev.dev), clk_alias);
+        r = clk_get_sys(dev_name(&od->pdev->dev), clk_alias);
         if (!IS_ERR(r)) {
-                pr_warning("omap_device: %s: alias %s already exists\n",
-                           dev_name(&od->pdev.dev), clk_alias);
+                dev_warn(&od->pdev->dev,
+                         "alias %s already exists\n", clk_alias);
                 clk_put(r);
                 return;
         }
 
         r = omap_clk_get_by_name(clk_name);
         if (IS_ERR(r)) {
-                pr_err("omap_device: %s: omap_clk_get_by_name for %s failed\n",
-                       dev_name(&od->pdev.dev), clk_name);
+                dev_err(&od->pdev->dev,
+                        "omap_clk_get_by_name for %s failed\n", clk_name);
                 return;
         }
 
-        l = clkdev_alloc(r, clk_alias, dev_name(&od->pdev.dev));
+        l = clkdev_alloc(r, clk_alias, dev_name(&od->pdev->dev));
         if (!l) {
-                pr_err("omap_device: %s: clkdev_alloc for %s failed\n",
-                       dev_name(&od->pdev.dev), clk_alias);
+                dev_err(&od->pdev->dev,
+                        "clkdev_alloc for %s failed\n", clk_alias);
                 return;
         }
 
@@ -304,6 +320,96 @@ static void _add_hwmod_clocks_clkdev(struct omap_device *od,
 }
 
 
+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;
+        struct device_node *node = pdev->dev.of_node;
+        const char *oh_name;
+        int oh_cnt, i, ret = 0;
+
+        oh_cnt = of_property_count_strings(node, "ti,hwmods");
+        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++) {
+                of_property_read_string_index(node, "ti,hwmods", i, &oh_name);
+                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(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 */
 
 /**
@@ -321,7 +427,7 @@ static void _add_hwmod_clocks_clkdev(struct omap_device *od,
  * return the context loss counter for that hwmod, otherwise return
  * zero.
  */
-u32 omap_device_get_context_loss_count(struct platform_device *pdev)
+int omap_device_get_context_loss_count(struct platform_device *pdev)
 {
         struct omap_device *od;
         u32 ret = 0;
@@ -343,7 +449,7 @@ u32 omap_device_get_context_loss_count(struct platform_device *pdev)
  * much memory to allocate before calling
  * omap_device_fill_resources().  Returns the count.
  */
-int omap_device_count_resources(struct omap_device *od)
+static int omap_device_count_resources(struct omap_device *od)
 {
         int c = 0;
         int i;
@@ -352,7 +458,7 @@ int omap_device_count_resources(struct omap_device *od)
                 c += omap_hwmod_count_resources(od->hwmods[i]);
 
         pr_debug("omap_device: %s: counted %d total resources across %d "
-                 "hwmods\n", od->pdev.name, c, od->hwmods_cnt);
+                 "hwmods\n", od->pdev->name, c, od->hwmods_cnt);
 
         return c;
 }
@@ -374,7 +480,8 @@ int omap_device_count_resources(struct omap_device *od)
  * functions to get device resources.  Hacking around the existing
  * platform_device code wastes memory.  Returns 0.
  */
-int omap_device_fill_resources(struct omap_device *od, struct resource *res)
+static int omap_device_fill_resources(struct omap_device *od,
+                                      struct resource *res)
 {
         int c = 0;
         int i, r;
@@ -389,6 +496,113 @@ int omap_device_fill_resources(struct omap_device *od, struct resource *res)
 }
 
 /**
+ * omap_device_alloc - allocate an omap_device
+ * @pdev: platform_device that will be included in this omap_device
+ * @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
+ *
+ * Convenience function for allocating an omap_device structure and filling
+ * hwmods, resources and pm_latency attributes.
+ *
+ * Returns an struct omap_device pointer or ERR_PTR() on error;
+ */
+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)
+{
+        int ret = -ENOMEM;
+        struct omap_device *od;
+        struct resource *res = NULL;
+        int i, res_count;
+        struct omap_hwmod **hwmods;
+
+        od = kzalloc(sizeof(struct omap_device), GFP_KERNEL);
+        if (!od) {
+                ret = -ENOMEM;
+                goto oda_exit1;
+        }
+        od->hwmods_cnt = oh_cnt;
+
+        hwmods = kmemdup(ohs, sizeof(struct omap_hwmod *) * oh_cnt, GFP_KERNEL);
+        if (!hwmods)
+                goto oda_exit2;
+
+        od->hwmods = hwmods;
+        od->pdev = pdev;
+
+        /*
+         * HACK: Ideally the resources from DT should match, and hwmod
+         * should just add the missing ones. Since the name is not
+         * properly populated by DT, stick to hwmod resources only.
+         */
+        if (pdev->num_resources && pdev->resource)
+                dev_warn(&pdev->dev, "%s(): resources already allocated %d\n",
+                        __func__, pdev->num_resources);
+
+        res_count = omap_device_count_resources(od);
+        if (res_count > 0) {
+                dev_dbg(&pdev->dev, "%s(): resources allocated from hwmod %d\n",
+                        __func__, res_count);
+                res = kzalloc(sizeof(struct resource) * res_count, GFP_KERNEL);
+                if (!res)
+                        goto oda_exit3;
+
+                omap_device_fill_resources(od, res);
+
+                ret = platform_device_add_resources(pdev, res, res_count);
+                kfree(res);
+
+                if (ret)
+                        goto oda_exit3;
+        }
+
+        if (!pm_lats) {
+                pm_lats = omap_default_latency;
+                pm_lats_cnt = ARRAY_SIZE(omap_default_latency);
+        }
+
+        od->pm_lats_cnt = pm_lats_cnt;
+        od->pm_lats = kmemdup(pm_lats,
+                        sizeof(struct omap_device_pm_latency) * pm_lats_cnt,
+                        GFP_KERNEL);
+        if (!od->pm_lats)
+                goto oda_exit3;
+
+        pdev->archdata.od = od;
+
+        for (i = 0; i < oh_cnt; i++) {
+                hwmods[i]->od = od;
+                _add_hwmod_clocks_clkdev(od, hwmods[i]);
+        }
+
+        return od;
+
+oda_exit3:
+        kfree(hwmods);
+oda_exit2:
+        kfree(od);
+oda_exit1:
+        dev_err(&pdev->dev, "omap_device: build failed (%d)\n", ret);
+
+        return ERR_PTR(ret);
+}
+
+static void omap_device_delete(struct omap_device *od)
+{
+        if (!od)
+                return;
+
+        od->pdev->archdata.od = NULL;
+        kfree(od->pm_lats);
+        kfree(od->hwmods);
+        kfree(od);
+}
+
+/**
  * omap_device_build - build and register an omap_device with one omap_hwmod
  * @pdev_name: name of the platform_device driver to use
  * @pdev_id: this platform_device's connection ID
@@ -405,7 +619,7 @@ int omap_device_fill_resources(struct omap_device *od, struct resource *res)
  * information.  Returns ERR_PTR(-EINVAL) if @oh is NULL; otherwise,
  * passes along the return value of omap_device_build_ss().
  */
-struct omap_device *omap_device_build(const char *pdev_name, int pdev_id,
+struct platform_device *omap_device_build(const char *pdev_name, int pdev_id,
                                       struct omap_hwmod *oh, void *pdata,
                                       int pdata_len,
                                       struct omap_device_pm_latency *pm_lats,
@@ -438,18 +652,15 @@ struct omap_device *omap_device_build(const char *pdev_name, int pdev_id,
  * platform_device record.  Returns an ERR_PTR() on error, or passes
  * along the return value of omap_device_register().
  */
-struct omap_device *omap_device_build_ss(const char *pdev_name, int pdev_id,
+struct platform_device *omap_device_build_ss(const char *pdev_name, int pdev_id,
                                          struct omap_hwmod **ohs, int oh_cnt,
                                          void *pdata, int pdata_len,
                                          struct omap_device_pm_latency *pm_lats,
                                          int pm_lats_cnt, int is_early_device)
 {
         int ret = -ENOMEM;
+        struct platform_device *pdev;
         struct omap_device *od;
-        char *pdev_name2;
-        struct resource *res = NULL;
-        int i, res_count;
-        struct omap_hwmod **hwmods;
 
         if (!ohs || oh_cnt == 0 || !pdev_name)
                 return ERR_PTR(-EINVAL);
@@ -457,72 +668,40 @@ struct omap_device *omap_device_build_ss(const char *pdev_name, int pdev_id,
         if (!pdata && pdata_len > 0)
                 return ERR_PTR(-EINVAL);
 
-        pr_debug("omap_device: %s: building with %d hwmods\n", pdev_name,
-                 oh_cnt);
-
-        od = kzalloc(sizeof(struct omap_device), GFP_KERNEL);
-        if (!od)
-                return ERR_PTR(-ENOMEM);
+        pdev = platform_device_alloc(pdev_name, pdev_id);
+        if (!pdev) {
+                ret = -ENOMEM;
+                goto odbs_exit;
+        }
 
-        od->hwmods_cnt = oh_cnt;
+        /* Set the dev_name early to allow dev_xxx in omap_device_alloc */
+        if (pdev->id != -1)
+                dev_set_name(&pdev->dev, "%s.%d", pdev->name,  pdev->id);
+        else
+                dev_set_name(&pdev->dev, "%s", pdev->name);
 
-        hwmods = kzalloc(sizeof(struct omap_hwmod *) * oh_cnt,
-                         GFP_KERNEL);
-        if (!hwmods)
+        od = omap_device_alloc(pdev, ohs, oh_cnt, pm_lats, pm_lats_cnt);
+        if (!od)
                 goto odbs_exit1;
 
-        memcpy(hwmods, ohs, sizeof(struct omap_hwmod *) * oh_cnt);
-        od->hwmods = hwmods;
-
-        pdev_name2 = kzalloc(strlen(pdev_name) + 1, GFP_KERNEL);
-        if (!pdev_name2)
-                goto odbs_exit2;
-        strcpy(pdev_name2, pdev_name);
-
-        od->pdev.name = pdev_name2;
-        od->pdev.id = pdev_id;
-
-        res_count = omap_device_count_resources(od);
-        if (res_count > 0) {
-                res = kzalloc(sizeof(struct resource) * res_count, GFP_KERNEL);
-                if (!res)
-                        goto odbs_exit3;
-        }
-        omap_device_fill_resources(od, res);
-
-        od->pdev.num_resources = res_count;
-        od->pdev.resource = res;
-
-        ret = platform_device_add_data(&od->pdev, pdata, pdata_len);
+        ret = platform_device_add_data(pdev, pdata, pdata_len);
         if (ret)
-                goto odbs_exit4;
-
-        od->pm_lats = pm_lats;
-        od->pm_lats_cnt = pm_lats_cnt;
+                goto odbs_exit2;
 
         if (is_early_device)
-                ret = omap_early_device_register(od);
+                ret = omap_early_device_register(pdev);
         else
-                ret = omap_device_register(od);
-
-        for (i = 0; i < oh_cnt; i++) {
-                hwmods[i]->od = od;
-                _add_hwmod_clocks_clkdev(od, hwmods[i]);
-        }
-
+                ret = omap_device_register(pdev);
         if (ret)
-                goto odbs_exit4;
+                goto odbs_exit2;
 
-        return od;
+        return pdev;
 
-odbs_exit4:
-        kfree(res);
-odbs_exit3:
-        kfree(pdev_name2);
 odbs_exit2:
-        kfree(hwmods);
+        omap_device_delete(od);
 odbs_exit1:
-        kfree(od);
+        platform_device_put(pdev);
+odbs_exit:
 
         pr_err("omap_device: %s: build failed (%d)\n", pdev_name, ret);
 
@@ -538,11 +717,11 @@ odbs_exit1:
  * platform_early_add_device() on the underlying platform_device.
  * Returns 0 by default.
  */
-int omap_early_device_register(struct omap_device *od)
+static int omap_early_device_register(struct platform_device *pdev)
 {
         struct platform_device *devices[1];
 
-        devices[0] = &(od->pdev);
+        devices[0] = pdev;
         early_platform_add_devices(devices, 1);
         return 0;
 }
@@ -615,6 +794,9 @@ static int _od_resume_noirq(struct device *dev)
 
         return pm_generic_resume_noirq(dev);
 }
+#else
+#define _od_suspend_noirq NULL
+#define _od_resume_noirq NULL
 #endif
 
 static struct dev_pm_domain omap_device_pm_domain = {
@@ -635,13 +817,13 @@ static struct dev_pm_domain omap_device_pm_domain = {
  * platform_device_register() on the underlying platform_device.
  * Returns the return value of platform_device_register().
  */
-int omap_device_register(struct omap_device *od)
+static int omap_device_register(struct platform_device *pdev)
 {
-        pr_debug("omap_device: %s: registering\n", od->pdev.name);
+        pr_debug("omap_device: %s: registering\n", pdev->name);
 
-        od->pdev.dev.parent = &omap_device_parent;
-        od->pdev.dev.pm_domain = &omap_device_pm_domain;
-        return platform_device_register(&od->pdev);
+        pdev->dev.parent = &omap_device_parent;
+        pdev->dev.pm_domain = &omap_device_pm_domain;
+        return platform_device_add(pdev);
 }
 
 
@@ -668,8 +850,9 @@ int omap_device_enable(struct platform_device *pdev)
         od = to_omap_device(pdev);
 
         if (od->_state == OMAP_DEVICE_STATE_ENABLED) {
-                WARN(1, "omap_device: %s.%d: %s() called from invalid state %d\n",
-                     od->pdev.name, od->pdev.id, __func__, od->_state);
+                dev_warn(&pdev->dev,
+                         "omap_device: %s() called from invalid state %d\n",
+                         __func__, od->_state);
                 return -EINVAL;
         }
 
@@ -707,8 +890,9 @@ int omap_device_idle(struct platform_device *pdev)
         od = to_omap_device(pdev);
 
         if (od->_state != OMAP_DEVICE_STATE_ENABLED) {
-                WARN(1, "omap_device: %s.%d: %s() called from invalid state %d\n",
-                     od->pdev.name, od->pdev.id, __func__, od->_state);
+                dev_warn(&pdev->dev,
+                         "omap_device: %s() called from invalid state %d\n",
+                         __func__, od->_state);
                 return -EINVAL;
         }
 
@@ -739,8 +923,9 @@ int omap_device_shutdown(struct platform_device *pdev)
 
         if (od->_state != OMAP_DEVICE_STATE_ENABLED &&
             od->_state != OMAP_DEVICE_STATE_IDLE) {
-                WARN(1, "omap_device: %s.%d: %s() called from invalid state %d\n",
-                     od->pdev.name, od->pdev.id, __func__, od->_state);
+                dev_warn(&pdev->dev,
+                         "omap_device: %s() called from invalid state %d\n",
+                         __func__, od->_state);
                 return -EINVAL;
         }
 
@@ -834,6 +1019,42 @@ void __iomem *omap_device_get_rt_va(struct omap_device *od)
         return omap_hwmod_get_mpu_rt_va(od->hwmods[0]);
 }
 
+/**
+ * omap_device_get_by_hwmod_name() - convert a hwmod name to
+ * device pointer.
+ * @oh_name: name of the hwmod device
+ *
+ * Returns back a struct device * pointer associated with a hwmod
+ * device represented by a hwmod_name
+ */
+struct device *omap_device_get_by_hwmod_name(const char *oh_name)
+{
+        struct omap_hwmod *oh;
+
+        if (!oh_name) {
+                WARN(1, "%s: no hwmod name!\n", __func__);
+                return ERR_PTR(-EINVAL);
+        }
+
+        oh = omap_hwmod_lookup(oh_name);
+        if (IS_ERR_OR_NULL(oh)) {
+                WARN(1, "%s: no hwmod for %s\n", __func__,
+                        oh_name);
+                return ERR_PTR(oh ? PTR_ERR(oh) : -ENODEV);
+        }
+        if (IS_ERR_OR_NULL(oh->od)) {
+                WARN(1, "%s: no omap_device for %s\n", __func__,
+                        oh_name);
+                return ERR_PTR(oh->od ? PTR_ERR(oh->od) : -ENODEV);
+        }
+
+        if (IS_ERR_OR_NULL(oh->od->pdev))
+                return ERR_PTR(oh->od->pdev ? PTR_ERR(oh->od->pdev) : -ENODEV);
+
+        return &oh->od->pdev->dev;
+}
+EXPORT_SYMBOL(omap_device_get_by_hwmod_name);
+
 /*
  * Public functions intended for use in omap_device_pm_latency
  * .activate_func and .deactivate_func function pointers
@@ -914,8 +1135,13 @@ 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);