diff options
Diffstat (limited to 'drivers/char/hw_random/omap3-rom-rng.c')
| -rw-r--r-- | drivers/char/hw_random/omap3-rom-rng.c | 168 |
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); |