summaryrefslogtreecommitdiff
path: root/drivers/char/hw_random/omap3-rom-rng.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/char/hw_random/omap3-rom-rng.c')
-rw-r--r--drivers/char/hw_random/omap3-rom-rng.c168
1 files changed, 104 insertions, 64 deletions
diff --git a/drivers/char/hw_random/omap3-rom-rng.c b/drivers/char/hw_random/omap3-rom-rng.c
index 38b719017186..e08a8887e718 100644
--- a/drivers/char/hw_random/omap3-rom-rng.c
+++ b/drivers/char/hw_random/omap3-rom-rng.c
@@ -11,8 +11,6 @@
* warranty of any kind, whether express or implied.
*/
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
#include <linux/module.h>
#include <linux/init.h>
#include <linux/random.h>
@@ -20,117 +18,159 @@
#include <linux/workqueue.h>
#include <linux/clk.h>
#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
#define RNG_RESET 0x01
#define RNG_GEN_PRNG_HW_INIT 0x02
#define RNG_GEN_HW 0x08
-/* param1: ptr, param2: count, param3: flag */
-static u32 (*omap3_rom_rng_call)(u32, u32, u32);
-
-static struct delayed_work idle_work;
-static int rng_idle;
-static struct clk *rng_clk;
+struct omap_rom_rng {
+ struct clk *clk;
+ struct device *dev;
+ struct hwrng ops;
+ u32 (*rom_rng_call)(u32 ptr, u32 count, u32 flag);
+};
-static void omap3_rom_rng_idle(struct work_struct *work)
+static int omap3_rom_rng_read(struct hwrng *rng, void *data, size_t max, bool w)
{
+ struct omap_rom_rng *ddata;
+ u32 ptr;
int r;
- r = omap3_rom_rng_call(0, 0, RNG_RESET);
- if (r != 0) {
- pr_err("reset failed: %d\n", r);
- return;
+ ddata = (struct omap_rom_rng *)rng->priv;
+
+ r = pm_runtime_get_sync(ddata->dev);
+ if (r < 0) {
+ pm_runtime_put_noidle(ddata->dev);
+
+ return r;
}
- clk_disable_unprepare(rng_clk);
- rng_idle = 1;
+
+ ptr = virt_to_phys(data);
+ r = ddata->rom_rng_call(ptr, 4, RNG_GEN_HW);
+ if (r != 0)
+ r = -EINVAL;
+ else
+ r = 4;
+
+ pm_runtime_mark_last_busy(ddata->dev);
+ pm_runtime_put_autosuspend(ddata->dev);
+
+ return r;
}
-static int omap3_rom_rng_get_random(void *buf, unsigned int count)
+static int __maybe_unused omap_rom_rng_runtime_suspend(struct device *dev)
{
- u32 r;
- u32 ptr;
+ struct omap_rom_rng *ddata;
+ int r;
- cancel_delayed_work_sync(&idle_work);
- if (rng_idle) {
- r = clk_prepare_enable(rng_clk);
- if (r)
- return r;
-
- r = omap3_rom_rng_call(0, 0, RNG_GEN_PRNG_HW_INIT);
- if (r != 0) {
- clk_disable_unprepare(rng_clk);
- pr_err("HW init failed: %d\n", r);
- return -EIO;
- }
- rng_idle = 0;
- }
+ ddata = dev_get_drvdata(dev);
- ptr = virt_to_phys(buf);
- r = omap3_rom_rng_call(ptr, count, RNG_GEN_HW);
- schedule_delayed_work(&idle_work, msecs_to_jiffies(500));
+ r = ddata->rom_rng_call(0, 0, RNG_RESET);
if (r != 0)
- return -EINVAL;
+ dev_err(dev, "reset failed: %d\n", r);
+
+ clk_disable_unprepare(ddata->clk);
+
return 0;
}
-static int omap3_rom_rng_read(struct hwrng *rng, void *data, size_t max, bool w)
+static int __maybe_unused omap_rom_rng_runtime_resume(struct device *dev)
{
+ struct omap_rom_rng *ddata;
int r;
- r = omap3_rom_rng_get_random(data, 4);
+ ddata = dev_get_drvdata(dev);
+
+ r = clk_prepare_enable(ddata->clk);
if (r < 0)
return r;
- return 4;
+
+ r = ddata->rom_rng_call(0, 0, RNG_GEN_PRNG_HW_INIT);
+ if (r != 0) {
+ clk_disable(ddata->clk);
+ dev_err(dev, "HW init failed: %d\n", r);
+
+ return -EIO;
+ }
+
+ return 0;
}
-static struct hwrng omap3_rom_rng_ops = {
- .name = "omap3-rom",
- .read = omap3_rom_rng_read,
-};
+static void omap_rom_rng_finish(void *data)
+{
+ struct omap_rom_rng *ddata = data;
+
+ pm_runtime_dont_use_autosuspend(ddata->dev);
+ pm_runtime_disable(ddata->dev);
+}
static int omap3_rom_rng_probe(struct platform_device *pdev)
{
+ struct omap_rom_rng *ddata;
int ret = 0;
- pr_info("initializing\n");
+ ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
+ if (!ddata)
+ return -ENOMEM;
- omap3_rom_rng_call = pdev->dev.platform_data;
- if (!omap3_rom_rng_call) {
- pr_err("omap3_rom_rng_call is NULL\n");
+ ddata->dev = &pdev->dev;
+ ddata->ops.priv = (unsigned long)ddata;
+ ddata->ops.name = "omap3-rom";
+ ddata->ops.read = of_device_get_match_data(&pdev->dev);
+ ddata->ops.quality = 900;
+ if (!ddata->ops.read) {
+ dev_err(&pdev->dev, "missing rom code handler\n");
+
+ return -ENODEV;
+ }
+ dev_set_drvdata(ddata->dev, ddata);
+
+ ddata->rom_rng_call = pdev->dev.platform_data;
+ if (!ddata->rom_rng_call) {
+ dev_err(ddata->dev, "rom_rng_call is NULL\n");
return -EINVAL;
}
- INIT_DELAYED_WORK(&idle_work, omap3_rom_rng_idle);
- rng_clk = devm_clk_get(&pdev->dev, "ick");
- if (IS_ERR(rng_clk)) {
- pr_err("unable to get RNG clock\n");
- return PTR_ERR(rng_clk);
+ ddata->clk = devm_clk_get(ddata->dev, "ick");
+ if (IS_ERR(ddata->clk)) {
+ dev_err(ddata->dev, "unable to get RNG clock\n");
+ return PTR_ERR(ddata->clk);
}
- /* Leave the RNG in reset state. */
- ret = clk_prepare_enable(rng_clk);
+ pm_runtime_enable(&pdev->dev);
+ pm_runtime_set_autosuspend_delay(&pdev->dev, 500);
+ pm_runtime_use_autosuspend(&pdev->dev);
+
+ ret = devm_add_action_or_reset(ddata->dev, omap_rom_rng_finish,
+ ddata);
if (ret)
return ret;
- omap3_rom_rng_idle(0);
- return hwrng_register(&omap3_rom_rng_ops);
+ return devm_hwrng_register(ddata->dev, &ddata->ops);
}
-static int omap3_rom_rng_remove(struct platform_device *pdev)
-{
- cancel_delayed_work_sync(&idle_work);
- hwrng_unregister(&omap3_rom_rng_ops);
- clk_disable_unprepare(rng_clk);
- return 0;
-}
+static const struct of_device_id omap_rom_rng_match[] = {
+ { .compatible = "nokia,n900-rom-rng", .data = omap3_rom_rng_read, },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, omap_rom_rng_match);
+
+static const struct dev_pm_ops omap_rom_rng_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(omap_rom_rng_runtime_suspend,
+ omap_rom_rng_runtime_resume)
+};
static struct platform_driver omap3_rom_rng_driver = {
.driver = {
.name = "omap3-rom-rng",
+ .of_match_table = omap_rom_rng_match,
+ .pm = &omap_rom_rng_pm_ops,
},
.probe = omap3_rom_rng_probe,
- .remove = omap3_rom_rng_remove,
};
module_platform_driver(omap3_rom_rng_driver);