diff options
author | Tony Lindgren <tony@atomide.com> | 2019-09-15 00:02:59 +0300 |
---|---|---|
committer | Herbert Xu <herbert@gondor.apana.org.au> | 2019-10-04 18:06:12 +0300 |
commit | 8d9d4bdc495f5e57877f9ec59af323fcbf3485fe (patch) | |
tree | 938f85c5c67683c4e73e6a1a195e8aac320b6deb /drivers/char/hw_random | |
parent | b8d665aed401b51297d8f2e9fbf2774e94d278bf (diff) | |
download | linux-8d9d4bdc495f5e57877f9ec59af323fcbf3485fe.tar.xz |
hwrng: omap3-rom - Use runtime PM instead of custom functions
Nowadays we have runtime PM, and we can use it with autosuspend_timeout
to idle things automatically. This allows us to get rid of the custom
PM implementation.
We enable clocks and init RNG in runtime_resume, and reset RNG and
disable clocks in runtime_suspend. And then omap3_rom_rng_read()
becomes very simple and we don't need the old functions for
omap3_rom_rng_idle() and omap3_rom_rng_get_random(). We can now also
get rid of pr_fmt as we're using dev_err instead.
Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: Adam Ford <aford173@gmail.com>
Cc: Pali Rohár <pali.rohar@gmail.com>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/char/hw_random')
-rw-r--r-- | drivers/char/hw_random/omap3-rom-rng.c | 126 |
1 files changed, 73 insertions, 53 deletions
diff --git a/drivers/char/hw_random/omap3-rom-rng.c b/drivers/char/hw_random/omap3-rom-rng.c index 749f6ec2bde1..dab62b1f5e48 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> @@ -23,73 +21,83 @@ #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); - struct omap_rom_rng { struct clk *clk; struct device *dev; struct hwrng ops; + u32 (*rom_rng_call)(u32 ptr, u32 count, u32 flag); }; -static struct delayed_work idle_work; -static int rng_idle; -static struct clk *rng_clk; - -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 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 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 int omap3_rom_rng_probe(struct platform_device *pdev) @@ -113,27 +121,33 @@ static int omap3_rom_rng_probe(struct platform_device *pdev) } dev_set_drvdata(ddata->dev, ddata); - omap3_rom_rng_call = pdev->dev.platform_data; - if (!omap3_rom_rng_call) { + 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); 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); } - rng_clk = ddata->clk; - /* Leave the RNG in reset state. */ - ret = clk_prepare_enable(ddata->clk); - if (ret) - return ret; - omap3_rom_rng_idle(0); + pm_runtime_enable(ddata->dev); + + ret = hwrng_register(&ddata->ops); + if (!ret) + goto err_disable; + + pm_runtime_set_autosuspend_delay(ddata->dev, 500); + pm_runtime_use_autosuspend(ddata->dev); + + return 0; - return hwrng_register(&ddata->ops); +err_disable: + pm_runtime_disable(ddata->dev); + + return ret; } static int omap3_rom_rng_remove(struct platform_device *pdev) @@ -141,10 +155,10 @@ static int omap3_rom_rng_remove(struct platform_device *pdev) struct omap_rom_rng *ddata; ddata = dev_get_drvdata(&pdev->dev); - cancel_delayed_work_sync(&idle_work); hwrng_unregister(&ddata->ops); - if (!rng_idle) - clk_disable_unprepare(rng_clk); + pm_runtime_dont_use_autosuspend(ddata->dev); + pm_runtime_disable(ddata->dev); + return 0; } @@ -154,10 +168,16 @@ static const struct of_device_id omap_rom_rng_match[] = { }; 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, |