diff options
Diffstat (limited to 'drivers/char/hw_random/imx-rngc.c')
| -rw-r--r-- | drivers/char/hw_random/imx-rngc.c | 165 |
1 files changed, 82 insertions, 83 deletions
diff --git a/drivers/char/hw_random/imx-rngc.c b/drivers/char/hw_random/imx-rngc.c index b05d676ca814..241664a9b5d9 100644 --- a/drivers/char/hw_random/imx-rngc.c +++ b/drivers/char/hw_random/imx-rngc.c @@ -13,10 +13,13 @@ #include <linux/clk.h> #include <linux/err.h> #include <linux/platform_device.h> +#include <linux/pm.h> +#include <linux/pm_runtime.h> #include <linux/interrupt.h> #include <linux/hw_random.h> #include <linux/completion.h> #include <linux/io.h> +#include <linux/bitfield.h> #define RNGC_VER_ID 0x0000 #define RNGC_COMMAND 0x0004 @@ -26,7 +29,7 @@ #define RNGC_FIFO 0x0014 /* the fields in the ver id register */ -#define RNGC_TYPE_SHIFT 28 +#define RNG_TYPE GENMASK(31, 28) #define RNGC_VER_MAJ_SHIFT 8 /* the rng_type field */ @@ -34,25 +37,25 @@ #define RNGC_TYPE_RNGC 0x2 -#define RNGC_CMD_CLR_ERR 0x00000020 -#define RNGC_CMD_CLR_INT 0x00000010 -#define RNGC_CMD_SEED 0x00000002 -#define RNGC_CMD_SELF_TEST 0x00000001 +#define RNGC_CMD_CLR_ERR BIT(5) +#define RNGC_CMD_CLR_INT BIT(4) +#define RNGC_CMD_SEED BIT(1) +#define RNGC_CMD_SELF_TEST BIT(0) -#define RNGC_CTRL_MASK_ERROR 0x00000040 -#define RNGC_CTRL_MASK_DONE 0x00000020 -#define RNGC_CTRL_AUTO_SEED 0x00000010 +#define RNGC_CTRL_MASK_ERROR BIT(6) +#define RNGC_CTRL_MASK_DONE BIT(5) +#define RNGC_CTRL_AUTO_SEED BIT(4) -#define RNGC_STATUS_ERROR 0x00010000 -#define RNGC_STATUS_FIFO_LEVEL_MASK 0x00000f00 -#define RNGC_STATUS_FIFO_LEVEL_SHIFT 8 -#define RNGC_STATUS_SEED_DONE 0x00000020 -#define RNGC_STATUS_ST_DONE 0x00000010 +#define RNGC_STATUS_ERROR BIT(16) +#define RNGC_STATUS_FIFO_LEVEL_MASK GENMASK(11, 8) +#define RNGC_STATUS_SEED_DONE BIT(5) +#define RNGC_STATUS_ST_DONE BIT(4) #define RNGC_ERROR_STATUS_STAT_ERR 0x00000008 -#define RNGC_TIMEOUT 3000 /* 3 sec */ - +#define RNGC_SELFTEST_TIMEOUT 2500 /* us */ +#define RNGC_SEED_TIMEOUT 200 /* ms */ +#define RNGC_PM_TIMEOUT 500 /* ms */ static bool self_test = true; module_param(self_test, bool, 0); @@ -110,7 +113,8 @@ static int imx_rngc_self_test(struct imx_rngc *rngc) cmd = readl(rngc->base + RNGC_COMMAND); writel(cmd | RNGC_CMD_SELF_TEST, rngc->base + RNGC_COMMAND); - ret = wait_for_completion_timeout(&rngc->rng_op_done, RNGC_TIMEOUT); + ret = wait_for_completion_timeout(&rngc->rng_op_done, + usecs_to_jiffies(RNGC_SELFTEST_TIMEOUT)); imx_rngc_irq_mask_clear(rngc); if (!ret) return -ETIMEDOUT; @@ -122,8 +126,11 @@ static int imx_rngc_read(struct hwrng *rng, void *data, size_t max, bool wait) { struct imx_rngc *rngc = container_of(rng, struct imx_rngc, rng); unsigned int status; - unsigned int level; - int retval = 0; + int err, retval = 0; + + err = pm_runtime_resume_and_get(rngc->dev); + if (err) + return err; while (max >= sizeof(u32)) { status = readl(rngc->base + RNGC_STATUS); @@ -132,11 +139,7 @@ static int imx_rngc_read(struct hwrng *rng, void *data, size_t max, bool wait) if (status & RNGC_STATUS_ERROR) break; - /* how many random numbers are in FIFO? [0-16] */ - level = (status & RNGC_STATUS_FIFO_LEVEL_MASK) >> - RNGC_STATUS_FIFO_LEVEL_SHIFT; - - if (level) { + if (status & RNGC_STATUS_FIFO_LEVEL_MASK) { /* retrieve a random number from FIFO */ *(u32 *)data = readl(rngc->base + RNGC_FIFO); @@ -145,6 +148,8 @@ static int imx_rngc_read(struct hwrng *rng, void *data, size_t max, bool wait) max -= sizeof(u32); } } + pm_runtime_mark_last_busy(rngc->dev); + pm_runtime_put(rngc->dev); return retval ? retval : -EIO; } @@ -173,7 +178,11 @@ static int imx_rngc_init(struct hwrng *rng) { struct imx_rngc *rngc = container_of(rng, struct imx_rngc, rng); u32 cmd, ctrl; - int ret; + int ret, err; + + err = pm_runtime_resume_and_get(rngc->dev); + if (err) + return err; /* clear error */ cmd = readl(rngc->base + RNGC_COMMAND); @@ -188,18 +197,17 @@ static int imx_rngc_init(struct hwrng *rng) writel(cmd | RNGC_CMD_SEED, rngc->base + RNGC_COMMAND); ret = wait_for_completion_timeout(&rngc->rng_op_done, - RNGC_TIMEOUT); - + msecs_to_jiffies(RNGC_SEED_TIMEOUT)); if (!ret) { - ret = -ETIMEDOUT; - goto err; + err = -ETIMEDOUT; + goto out; } } while (rngc->err_reg == RNGC_ERROR_STATUS_STAT_ERR); if (rngc->err_reg) { - ret = -EIO; - goto err; + err = -EIO; + goto out; } /* @@ -210,26 +218,32 @@ static int imx_rngc_init(struct hwrng *rng) ctrl |= RNGC_CTRL_AUTO_SEED; writel(ctrl, rngc->base + RNGC_CONTROL); +out: /* * if initialisation was successful, we keep the interrupt * unmasked until imx_rngc_cleanup is called * we mask the interrupt ourselves if we return an error */ - return 0; + if (err) + imx_rngc_irq_mask_clear(rngc); -err: - imx_rngc_irq_mask_clear(rngc); - return ret; + pm_runtime_put(rngc->dev); + return err; } static void imx_rngc_cleanup(struct hwrng *rng) { struct imx_rngc *rngc = container_of(rng, struct imx_rngc, rng); + int err; - imx_rngc_irq_mask_clear(rngc); + err = pm_runtime_resume_and_get(rngc->dev); + if (!err) { + imx_rngc_irq_mask_clear(rngc); + pm_runtime_put(rngc->dev); + } } -static int imx_rngc_probe(struct platform_device *pdev) +static int __init imx_rngc_probe(struct platform_device *pdev) { struct imx_rngc *rngc; int ret; @@ -246,35 +260,24 @@ static int imx_rngc_probe(struct platform_device *pdev) return PTR_ERR(rngc->base); rngc->clk = devm_clk_get(&pdev->dev, NULL); - if (IS_ERR(rngc->clk)) { - dev_err(&pdev->dev, "Can not get rng_clk\n"); - return PTR_ERR(rngc->clk); - } + if (IS_ERR(rngc->clk)) + return dev_err_probe(&pdev->dev, PTR_ERR(rngc->clk), "Cannot get rng_clk\n"); irq = platform_get_irq(pdev, 0); if (irq < 0) return irq; - ret = clk_prepare_enable(rngc->clk); - if (ret) - return ret; + clk_prepare_enable(rngc->clk); ver_id = readl(rngc->base + RNGC_VER_ID); - rng_type = ver_id >> RNGC_TYPE_SHIFT; + rng_type = FIELD_GET(RNG_TYPE, ver_id); /* * This driver supports only RNGC and RNGB. (There's a different * driver for RNGA.) */ if (rng_type != RNGC_TYPE_RNGC && rng_type != RNGC_TYPE_RNGB) { - ret = -ENODEV; - goto err; - } - - ret = devm_request_irq(&pdev->dev, - irq, imx_rngc_irq, 0, pdev->name, (void *)rngc); - if (ret) { - dev_err(rngc->dev, "Can't get interrupt working.\n"); - goto err; + clk_disable_unprepare(rngc->clk); + return -ENODEV; } init_completion(&rngc->rng_op_done); @@ -290,44 +293,38 @@ static int imx_rngc_probe(struct platform_device *pdev) imx_rngc_irq_mask_clear(rngc); + ret = devm_request_irq(&pdev->dev, + irq, imx_rngc_irq, 0, pdev->name, (void *)rngc); + if (ret) { + clk_disable_unprepare(rngc->clk); + return dev_err_probe(&pdev->dev, ret, "Can't get interrupt working.\n"); + } + if (self_test) { ret = imx_rngc_self_test(rngc); if (ret) { - dev_err(rngc->dev, "self test failed\n"); - goto err; + clk_disable_unprepare(rngc->clk); + return dev_err_probe(&pdev->dev, ret, "self test failed\n"); } } - ret = hwrng_register(&rngc->rng); - if (ret) { - dev_err(&pdev->dev, "hwrng registration failed\n"); - goto err; - } + pm_runtime_set_autosuspend_delay(&pdev->dev, RNGC_PM_TIMEOUT); + pm_runtime_use_autosuspend(&pdev->dev); + pm_runtime_set_active(&pdev->dev); + devm_pm_runtime_enable(&pdev->dev); + + ret = devm_hwrng_register(&pdev->dev, &rngc->rng); + if (ret) + return dev_err_probe(&pdev->dev, ret, "hwrng registration failed\n"); dev_info(&pdev->dev, "Freescale RNG%c registered (HW revision %d.%02d)\n", rng_type == RNGC_TYPE_RNGB ? 'B' : 'C', (ver_id >> RNGC_VER_MAJ_SHIFT) & 0xff, ver_id & 0xff); return 0; - -err: - clk_disable_unprepare(rngc->clk); - - return ret; } -static int __exit imx_rngc_remove(struct platform_device *pdev) -{ - struct imx_rngc *rngc = platform_get_drvdata(pdev); - - hwrng_unregister(&rngc->rng); - - clk_disable_unprepare(rngc->clk); - - return 0; -} - -static int __maybe_unused imx_rngc_suspend(struct device *dev) +static int imx_rngc_suspend(struct device *dev) { struct imx_rngc *rngc = dev_get_drvdata(dev); @@ -336,7 +333,7 @@ static int __maybe_unused imx_rngc_suspend(struct device *dev) return 0; } -static int __maybe_unused imx_rngc_resume(struct device *dev) +static int imx_rngc_resume(struct device *dev) { struct imx_rngc *rngc = dev_get_drvdata(dev); @@ -345,21 +342,23 @@ static int __maybe_unused imx_rngc_resume(struct device *dev) return 0; } -static SIMPLE_DEV_PM_OPS(imx_rngc_pm_ops, imx_rngc_suspend, imx_rngc_resume); +static const struct dev_pm_ops imx_rngc_pm_ops = { + SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume) + RUNTIME_PM_OPS(imx_rngc_suspend, imx_rngc_resume, NULL) +}; static const struct of_device_id imx_rngc_dt_ids[] = { - { .compatible = "fsl,imx25-rngb", .data = NULL, }, + { .compatible = "fsl,imx25-rngb" }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, imx_rngc_dt_ids); static struct platform_driver imx_rngc_driver = { .driver = { - .name = "imx_rngc", - .pm = &imx_rngc_pm_ops, + .name = KBUILD_MODNAME, + .pm = pm_ptr(&imx_rngc_pm_ops), .of_match_table = imx_rngc_dt_ids, }, - .remove = __exit_p(imx_rngc_remove), }; module_platform_driver_probe(imx_rngc_driver, imx_rngc_probe); |