diff options
Diffstat (limited to 'drivers/char/hw_random/cctrng.c')
| -rw-r--r-- | drivers/char/hw_random/cctrng.c | 735 |
1 files changed, 735 insertions, 0 deletions
diff --git a/drivers/char/hw_random/cctrng.c b/drivers/char/hw_random/cctrng.c new file mode 100644 index 000000000000..619148fb2dc9 --- /dev/null +++ b/drivers/char/hw_random/cctrng.c @@ -0,0 +1,735 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (C) 2019-2020 ARM Limited or its affiliates. */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/clk.h> +#include <linux/hw_random.h> +#include <linux/io.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/interrupt.h> +#include <linux/irqreturn.h> +#include <linux/workqueue.h> +#include <linux/circ_buf.h> +#include <linux/completion.h> +#include <linux/of.h> +#include <linux/bitfield.h> +#include <linux/fips.h> + +#include "cctrng.h" + +#define CC_REG_LOW(name) (name ## _BIT_SHIFT) +#define CC_REG_HIGH(name) (CC_REG_LOW(name) + name ## _BIT_SIZE - 1) +#define CC_GENMASK(name) GENMASK(CC_REG_HIGH(name), CC_REG_LOW(name)) + +#define CC_REG_FLD_GET(reg_name, fld_name, reg_val) \ + (FIELD_GET(CC_GENMASK(CC_ ## reg_name ## _ ## fld_name), reg_val)) + +#define CC_HW_RESET_LOOP_COUNT 10 +#define CC_TRNG_SUSPEND_TIMEOUT 3000 + +/* data circular buffer in words must be: + * - of a power-of-2 size (limitation of circ_buf.h macros) + * - at least 6, the size generated in the EHR according to HW implementation + */ +#define CCTRNG_DATA_BUF_WORDS 32 + +/* The timeout for the TRNG operation should be calculated with the formula: + * Timeout = EHR_NUM * VN_COEFF * EHR_LENGTH * SAMPLE_CNT * SCALE_VALUE + * while: + * - SAMPLE_CNT is input value from the characterisation process + * - all the rest are constants + */ +#define EHR_NUM 1 +#define VN_COEFF 4 +#define EHR_LENGTH CC_TRNG_EHR_IN_BITS +#define SCALE_VALUE 2 +#define CCTRNG_TIMEOUT(smpl_cnt) \ + (EHR_NUM * VN_COEFF * EHR_LENGTH * smpl_cnt * SCALE_VALUE) + +struct cctrng_drvdata { + struct platform_device *pdev; + void __iomem *cc_base; + struct clk *clk; + struct hwrng rng; + u32 active_rosc; + /* Sampling interval for each ring oscillator: + * count of ring oscillator cycles between consecutive bits sampling. + * Value of 0 indicates non-valid rosc + */ + u32 smpl_ratio[CC_TRNG_NUM_OF_ROSCS]; + + u32 data_buf[CCTRNG_DATA_BUF_WORDS]; + struct circ_buf circ; + struct work_struct compwork; + struct work_struct startwork; + + /* pending_hw - 1 when HW is pending, 0 when it is idle */ + atomic_t pending_hw; + + /* protects against multiple concurrent consumers of data_buf */ + spinlock_t read_lock; +}; + + +/* functions for write/read CC registers */ +static inline void cc_iowrite(struct cctrng_drvdata *drvdata, u32 reg, u32 val) +{ + iowrite32(val, (drvdata->cc_base + reg)); +} +static inline u32 cc_ioread(struct cctrng_drvdata *drvdata, u32 reg) +{ + return ioread32(drvdata->cc_base + reg); +} + + +static int cc_trng_pm_get(struct device *dev) +{ + int rc = 0; + + rc = pm_runtime_get_sync(dev); + + /* pm_runtime_get_sync() can return 1 as a valid return code */ + return (rc == 1 ? 0 : rc); +} + +static void cc_trng_pm_put_suspend(struct device *dev) +{ + int rc = 0; + + pm_runtime_mark_last_busy(dev); + rc = pm_runtime_put_autosuspend(dev); + if (rc) + dev_err(dev, "pm_runtime_put_autosuspend returned %x\n", rc); +} + +static int cc_trng_pm_init(struct cctrng_drvdata *drvdata) +{ + struct device *dev = &(drvdata->pdev->dev); + + /* must be before the enabling to avoid redundant suspending */ + pm_runtime_set_autosuspend_delay(dev, CC_TRNG_SUSPEND_TIMEOUT); + pm_runtime_use_autosuspend(dev); + /* set us as active - note we won't do PM ops until cc_trng_pm_go()! */ + return pm_runtime_set_active(dev); +} + +static void cc_trng_pm_go(struct cctrng_drvdata *drvdata) +{ + struct device *dev = &(drvdata->pdev->dev); + + /* enable the PM module*/ + pm_runtime_enable(dev); +} + +static void cc_trng_pm_fini(struct cctrng_drvdata *drvdata) +{ + struct device *dev = &(drvdata->pdev->dev); + + pm_runtime_disable(dev); +} + + +static inline int cc_trng_parse_sampling_ratio(struct cctrng_drvdata *drvdata) +{ + struct device *dev = &(drvdata->pdev->dev); + struct device_node *np = drvdata->pdev->dev.of_node; + int rc; + int i; + /* ret will be set to 0 if at least one rosc has (sampling ratio > 0) */ + int ret = -EINVAL; + + rc = of_property_read_u32_array(np, "arm,rosc-ratio", + drvdata->smpl_ratio, + CC_TRNG_NUM_OF_ROSCS); + if (rc) { + /* arm,rosc-ratio was not found in device tree */ + return rc; + } + + /* verify that at least one rosc has (sampling ratio > 0) */ + for (i = 0; i < CC_TRNG_NUM_OF_ROSCS; ++i) { + dev_dbg(dev, "rosc %d sampling ratio %u", + i, drvdata->smpl_ratio[i]); + + if (drvdata->smpl_ratio[i] > 0) + ret = 0; + } + + return ret; +} + +static int cc_trng_change_rosc(struct cctrng_drvdata *drvdata) +{ + struct device *dev = &(drvdata->pdev->dev); + + dev_dbg(dev, "cctrng change rosc (was %d)\n", drvdata->active_rosc); + drvdata->active_rosc += 1; + + while (drvdata->active_rosc < CC_TRNG_NUM_OF_ROSCS) { + if (drvdata->smpl_ratio[drvdata->active_rosc] > 0) + return 0; + + drvdata->active_rosc += 1; + } + return -EINVAL; +} + + +static void cc_trng_enable_rnd_source(struct cctrng_drvdata *drvdata) +{ + u32 max_cycles; + + /* Set watchdog threshold to maximal allowed time (in CPU cycles) */ + max_cycles = CCTRNG_TIMEOUT(drvdata->smpl_ratio[drvdata->active_rosc]); + cc_iowrite(drvdata, CC_RNG_WATCHDOG_VAL_REG_OFFSET, max_cycles); + + /* enable the RND source */ + cc_iowrite(drvdata, CC_RND_SOURCE_ENABLE_REG_OFFSET, 0x1); + + /* unmask RNG interrupts */ + cc_iowrite(drvdata, CC_RNG_IMR_REG_OFFSET, (u32)~CC_RNG_INT_MASK); +} + + +/* increase circular data buffer index (head/tail) */ +static inline void circ_idx_inc(int *idx, int bytes) +{ + *idx += (bytes + 3) >> 2; + *idx &= (CCTRNG_DATA_BUF_WORDS - 1); +} + +static inline size_t circ_buf_space(struct cctrng_drvdata *drvdata) +{ + return CIRC_SPACE(drvdata->circ.head, + drvdata->circ.tail, CCTRNG_DATA_BUF_WORDS); + +} + +static int cctrng_read(struct hwrng *rng, void *data, size_t max, bool wait) +{ + /* current implementation ignores "wait" */ + + struct cctrng_drvdata *drvdata = (struct cctrng_drvdata *)rng->priv; + struct device *dev = &(drvdata->pdev->dev); + u32 *buf = (u32 *)drvdata->circ.buf; + size_t copied = 0; + size_t cnt_w; + size_t size; + size_t left; + + if (!spin_trylock(&drvdata->read_lock)) { + /* concurrent consumers from data_buf cannot be served */ + dev_dbg_ratelimited(dev, "unable to hold lock\n"); + return 0; + } + + /* copy till end of data buffer (without wrap back) */ + cnt_w = CIRC_CNT_TO_END(drvdata->circ.head, + drvdata->circ.tail, CCTRNG_DATA_BUF_WORDS); + size = min((cnt_w<<2), max); + memcpy(data, &(buf[drvdata->circ.tail]), size); + copied = size; + circ_idx_inc(&drvdata->circ.tail, size); + /* copy rest of data in data buffer */ + left = max - copied; + if (left > 0) { + cnt_w = CIRC_CNT(drvdata->circ.head, + drvdata->circ.tail, CCTRNG_DATA_BUF_WORDS); + size = min((cnt_w<<2), left); + memcpy(data, &(buf[drvdata->circ.tail]), size); + copied += size; + circ_idx_inc(&drvdata->circ.tail, size); + } + + spin_unlock(&drvdata->read_lock); + + if (circ_buf_space(drvdata) >= CC_TRNG_EHR_IN_WORDS) { + if (atomic_cmpxchg(&drvdata->pending_hw, 0, 1) == 0) { + /* re-check space in buffer to avoid potential race */ + if (circ_buf_space(drvdata) >= CC_TRNG_EHR_IN_WORDS) { + /* increment device's usage counter */ + int rc = cc_trng_pm_get(dev); + + if (rc) { + dev_err(dev, + "cc_trng_pm_get returned %x\n", + rc); + return rc; + } + + /* schedule execution of deferred work handler + * for filling of data buffer + */ + schedule_work(&drvdata->startwork); + } else { + atomic_set(&drvdata->pending_hw, 0); + } + } + } + + return copied; +} + +static void cc_trng_hw_trigger(struct cctrng_drvdata *drvdata) +{ + u32 tmp_smpl_cnt = 0; + struct device *dev = &(drvdata->pdev->dev); + + dev_dbg(dev, "cctrng hw trigger.\n"); + + /* enable the HW RND clock */ + cc_iowrite(drvdata, CC_RNG_CLK_ENABLE_REG_OFFSET, 0x1); + + /* do software reset */ + cc_iowrite(drvdata, CC_RNG_SW_RESET_REG_OFFSET, 0x1); + /* in order to verify that the reset has completed, + * the sample count need to be verified + */ + do { + /* enable the HW RND clock */ + cc_iowrite(drvdata, CC_RNG_CLK_ENABLE_REG_OFFSET, 0x1); + + /* set sampling ratio (rng_clocks) between consecutive bits */ + cc_iowrite(drvdata, CC_SAMPLE_CNT1_REG_OFFSET, + drvdata->smpl_ratio[drvdata->active_rosc]); + + /* read the sampling ratio */ + tmp_smpl_cnt = cc_ioread(drvdata, CC_SAMPLE_CNT1_REG_OFFSET); + + } while (tmp_smpl_cnt != drvdata->smpl_ratio[drvdata->active_rosc]); + + /* disable the RND source for setting new parameters in HW */ + cc_iowrite(drvdata, CC_RND_SOURCE_ENABLE_REG_OFFSET, 0); + + cc_iowrite(drvdata, CC_RNG_ICR_REG_OFFSET, 0xFFFFFFFF); + + cc_iowrite(drvdata, CC_TRNG_CONFIG_REG_OFFSET, drvdata->active_rosc); + + /* Debug Control register: set to 0 - no bypasses */ + cc_iowrite(drvdata, CC_TRNG_DEBUG_CONTROL_REG_OFFSET, 0); + + cc_trng_enable_rnd_source(drvdata); +} + +static void cc_trng_compwork_handler(struct work_struct *w) +{ + u32 isr = 0; + u32 ehr_valid = 0; + struct cctrng_drvdata *drvdata = + container_of(w, struct cctrng_drvdata, compwork); + struct device *dev = &(drvdata->pdev->dev); + int i; + + /* stop DMA and the RNG source */ + cc_iowrite(drvdata, CC_RNG_DMA_ENABLE_REG_OFFSET, 0); + cc_iowrite(drvdata, CC_RND_SOURCE_ENABLE_REG_OFFSET, 0); + + /* read RNG_ISR and check for errors */ + isr = cc_ioread(drvdata, CC_RNG_ISR_REG_OFFSET); + ehr_valid = CC_REG_FLD_GET(RNG_ISR, EHR_VALID, isr); + dev_dbg(dev, "Got RNG_ISR=0x%08X (EHR_VALID=%u)\n", isr, ehr_valid); + + if (fips_enabled && CC_REG_FLD_GET(RNG_ISR, CRNGT_ERR, isr)) { + fips_fail_notify(); + /* FIPS error is fatal */ + panic("Got HW CRNGT error while fips is enabled!\n"); + } + + /* Clear all pending RNG interrupts */ + cc_iowrite(drvdata, CC_RNG_ICR_REG_OFFSET, isr); + + + if (!ehr_valid) { + /* in case of AUTOCORR/TIMEOUT error, try the next ROSC */ + if (CC_REG_FLD_GET(RNG_ISR, AUTOCORR_ERR, isr) || + CC_REG_FLD_GET(RNG_ISR, WATCHDOG, isr)) { + dev_dbg(dev, "cctrng autocorr/timeout error.\n"); + goto next_rosc; + } + + /* in case of VN error, ignore it */ + } + + /* read EHR data from registers */ + for (i = 0; i < CC_TRNG_EHR_IN_WORDS; i++) { + /* calc word ptr in data_buf */ + u32 *buf = (u32 *)drvdata->circ.buf; + + buf[drvdata->circ.head] = cc_ioread(drvdata, + CC_EHR_DATA_0_REG_OFFSET + (i*sizeof(u32))); + + /* EHR_DATA registers are cleared on read. In case 0 value was + * returned, restart the entropy collection. + */ + if (buf[drvdata->circ.head] == 0) { + dev_dbg(dev, "Got 0 value in EHR. active_rosc %u\n", + drvdata->active_rosc); + goto next_rosc; + } + + circ_idx_inc(&drvdata->circ.head, 1<<2); + } + + atomic_set(&drvdata->pending_hw, 0); + + /* continue to fill data buffer if needed */ + if (circ_buf_space(drvdata) >= CC_TRNG_EHR_IN_WORDS) { + if (atomic_cmpxchg(&drvdata->pending_hw, 0, 1) == 0) { + /* Re-enable rnd source */ + cc_trng_enable_rnd_source(drvdata); + return; + } + } + + cc_trng_pm_put_suspend(dev); + + dev_dbg(dev, "compwork handler done\n"); + return; + +next_rosc: + if ((circ_buf_space(drvdata) >= CC_TRNG_EHR_IN_WORDS) && + (cc_trng_change_rosc(drvdata) == 0)) { + /* trigger trng hw with next rosc */ + cc_trng_hw_trigger(drvdata); + } else { + atomic_set(&drvdata->pending_hw, 0); + cc_trng_pm_put_suspend(dev); + } +} + +static irqreturn_t cc_isr(int irq, void *dev_id) +{ + struct cctrng_drvdata *drvdata = (struct cctrng_drvdata *)dev_id; + struct device *dev = &(drvdata->pdev->dev); + u32 irr; + + /* if driver suspended return, probably shared interrupt */ + if (pm_runtime_suspended(dev)) + return IRQ_NONE; + + /* read the interrupt status */ + irr = cc_ioread(drvdata, CC_HOST_RGF_IRR_REG_OFFSET); + dev_dbg(dev, "Got IRR=0x%08X\n", irr); + + if (irr == 0) /* Probably shared interrupt line */ + return IRQ_NONE; + + /* clear interrupt - must be before processing events */ + cc_iowrite(drvdata, CC_HOST_RGF_ICR_REG_OFFSET, irr); + + /* RNG interrupt - most probable */ + if (irr & CC_HOST_RNG_IRQ_MASK) { + /* Mask RNG interrupts - will be unmasked in deferred work */ + cc_iowrite(drvdata, CC_RNG_IMR_REG_OFFSET, 0xFFFFFFFF); + + /* We clear RNG interrupt here, + * to avoid it from firing as we'll unmask RNG interrupts. + */ + cc_iowrite(drvdata, CC_HOST_RGF_ICR_REG_OFFSET, + CC_HOST_RNG_IRQ_MASK); + + irr &= ~CC_HOST_RNG_IRQ_MASK; + + /* schedule execution of deferred work handler */ + schedule_work(&drvdata->compwork); + } + + if (irr) { + dev_dbg_ratelimited(dev, + "IRR includes unknown cause bits (0x%08X)\n", + irr); + /* Just warning */ + } + + return IRQ_HANDLED; +} + +static void cc_trng_startwork_handler(struct work_struct *w) +{ + struct cctrng_drvdata *drvdata = + container_of(w, struct cctrng_drvdata, startwork); + + drvdata->active_rosc = 0; + cc_trng_hw_trigger(drvdata); +} + + +static int cc_trng_clk_init(struct cctrng_drvdata *drvdata) +{ + struct clk *clk; + struct device *dev = &(drvdata->pdev->dev); + int rc = 0; + + clk = devm_clk_get_optional(dev, NULL); + if (IS_ERR(clk)) { + if (PTR_ERR(clk) != -EPROBE_DEFER) + dev_err(dev, "Error getting clock: %pe\n", clk); + return PTR_ERR(clk); + } + drvdata->clk = clk; + + rc = clk_prepare_enable(drvdata->clk); + if (rc) { + dev_err(dev, "Failed to enable clock\n"); + return rc; + } + + return 0; +} + +static void cc_trng_clk_fini(struct cctrng_drvdata *drvdata) +{ + clk_disable_unprepare(drvdata->clk); +} + + +static int cctrng_probe(struct platform_device *pdev) +{ + struct resource *req_mem_cc_regs = NULL; + struct cctrng_drvdata *drvdata; + struct device *dev = &pdev->dev; + int rc = 0; + u32 val; + int irq; + + drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL); + if (!drvdata) + return -ENOMEM; + + drvdata->rng.name = devm_kstrdup(dev, dev_name(dev), GFP_KERNEL); + if (!drvdata->rng.name) + return -ENOMEM; + + drvdata->rng.read = cctrng_read; + drvdata->rng.priv = (unsigned long)drvdata; + drvdata->rng.quality = CC_TRNG_QUALITY; + + platform_set_drvdata(pdev, drvdata); + drvdata->pdev = pdev; + + drvdata->circ.buf = (char *)drvdata->data_buf; + + /* Get device resources */ + /* First CC registers space */ + req_mem_cc_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); + /* Map registers space */ + drvdata->cc_base = devm_ioremap_resource(dev, req_mem_cc_regs); + if (IS_ERR(drvdata->cc_base)) { + dev_err(dev, "Failed to ioremap registers"); + return PTR_ERR(drvdata->cc_base); + } + + dev_dbg(dev, "Got MEM resource (%s): %pR\n", req_mem_cc_regs->name, + req_mem_cc_regs); + dev_dbg(dev, "CC registers mapped from %pa to 0x%p\n", + &req_mem_cc_regs->start, drvdata->cc_base); + + /* Then IRQ */ + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_err(dev, "Failed getting IRQ resource\n"); + return irq; + } + + /* parse sampling rate from device tree */ + rc = cc_trng_parse_sampling_ratio(drvdata); + if (rc) { + dev_err(dev, "Failed to get legal sampling ratio for rosc\n"); + return rc; + } + + rc = cc_trng_clk_init(drvdata); + if (rc) { + dev_err(dev, "cc_trng_clk_init failed\n"); + return rc; + } + + INIT_WORK(&drvdata->compwork, cc_trng_compwork_handler); + INIT_WORK(&drvdata->startwork, cc_trng_startwork_handler); + spin_lock_init(&drvdata->read_lock); + + /* register the driver isr function */ + rc = devm_request_irq(dev, irq, cc_isr, IRQF_SHARED, "cctrng", drvdata); + if (rc) { + dev_err(dev, "Could not register to interrupt %d\n", irq); + goto post_clk_err; + } + dev_dbg(dev, "Registered to IRQ: %d\n", irq); + + /* Clear all pending interrupts */ + val = cc_ioread(drvdata, CC_HOST_RGF_IRR_REG_OFFSET); + dev_dbg(dev, "IRR=0x%08X\n", val); + cc_iowrite(drvdata, CC_HOST_RGF_ICR_REG_OFFSET, val); + + /* unmask HOST RNG interrupt */ + cc_iowrite(drvdata, CC_HOST_RGF_IMR_REG_OFFSET, + cc_ioread(drvdata, CC_HOST_RGF_IMR_REG_OFFSET) & + ~CC_HOST_RNG_IRQ_MASK); + + /* init PM */ + rc = cc_trng_pm_init(drvdata); + if (rc) { + dev_err(dev, "cc_trng_pm_init failed\n"); + goto post_clk_err; + } + + /* increment device's usage counter */ + rc = cc_trng_pm_get(dev); + if (rc) { + dev_err(dev, "cc_trng_pm_get returned %x\n", rc); + goto post_pm_err; + } + + /* set pending_hw to verify that HW won't be triggered from read */ + atomic_set(&drvdata->pending_hw, 1); + + /* registration of the hwrng device */ + rc = hwrng_register(&drvdata->rng); + if (rc) { + dev_err(dev, "Could not register hwrng device.\n"); + goto post_pm_err; + } + + /* trigger HW to start generate data */ + drvdata->active_rosc = 0; + cc_trng_hw_trigger(drvdata); + + /* All set, we can allow auto-suspend */ + cc_trng_pm_go(drvdata); + + dev_info(dev, "ARM cctrng device initialized\n"); + + return 0; + +post_pm_err: + cc_trng_pm_fini(drvdata); + +post_clk_err: + cc_trng_clk_fini(drvdata); + + return rc; +} + +static int cctrng_remove(struct platform_device *pdev) +{ + struct cctrng_drvdata *drvdata = platform_get_drvdata(pdev); + struct device *dev = &pdev->dev; + + dev_dbg(dev, "Releasing cctrng resources...\n"); + + hwrng_unregister(&drvdata->rng); + + cc_trng_pm_fini(drvdata); + + cc_trng_clk_fini(drvdata); + + dev_info(dev, "ARM cctrng device terminated\n"); + + return 0; +} + +static int __maybe_unused cctrng_suspend(struct device *dev) +{ + struct cctrng_drvdata *drvdata = dev_get_drvdata(dev); + + dev_dbg(dev, "set HOST_POWER_DOWN_EN\n"); + cc_iowrite(drvdata, CC_HOST_POWER_DOWN_EN_REG_OFFSET, + POWER_DOWN_ENABLE); + + clk_disable_unprepare(drvdata->clk); + + return 0; +} + +static bool cctrng_wait_for_reset_completion(struct cctrng_drvdata *drvdata) +{ + unsigned int val; + unsigned int i; + + for (i = 0; i < CC_HW_RESET_LOOP_COUNT; i++) { + /* in cc7x3 NVM_IS_IDLE indicates that CC reset is + * completed and device is fully functional + */ + val = cc_ioread(drvdata, CC_NVM_IS_IDLE_REG_OFFSET); + if (val & BIT(CC_NVM_IS_IDLE_VALUE_BIT_SHIFT)) { + /* hw indicate reset completed */ + return true; + } + /* allow scheduling other process on the processor */ + schedule(); + } + /* reset not completed */ + return false; +} + +static int __maybe_unused cctrng_resume(struct device *dev) +{ + struct cctrng_drvdata *drvdata = dev_get_drvdata(dev); + int rc; + + dev_dbg(dev, "unset HOST_POWER_DOWN_EN\n"); + /* Enables the device source clk */ + rc = clk_prepare_enable(drvdata->clk); + if (rc) { + dev_err(dev, "failed getting clock back on. We're toast.\n"); + return rc; + } + + /* wait for Cryptocell reset completion */ + if (!cctrng_wait_for_reset_completion(drvdata)) { + dev_err(dev, "Cryptocell reset not completed"); + return -EBUSY; + } + + /* unmask HOST RNG interrupt */ + cc_iowrite(drvdata, CC_HOST_RGF_IMR_REG_OFFSET, + cc_ioread(drvdata, CC_HOST_RGF_IMR_REG_OFFSET) & + ~CC_HOST_RNG_IRQ_MASK); + + cc_iowrite(drvdata, CC_HOST_POWER_DOWN_EN_REG_OFFSET, + POWER_DOWN_DISABLE); + + return 0; +} + +static UNIVERSAL_DEV_PM_OPS(cctrng_pm, cctrng_suspend, cctrng_resume, NULL); + +static const struct of_device_id arm_cctrng_dt_match[] = { + { .compatible = "arm,cryptocell-713-trng", }, + { .compatible = "arm,cryptocell-703-trng", }, + {}, +}; +MODULE_DEVICE_TABLE(of, arm_cctrng_dt_match); + +static struct platform_driver cctrng_driver = { + .driver = { + .name = "cctrng", + .of_match_table = arm_cctrng_dt_match, + .pm = &cctrng_pm, + }, + .probe = cctrng_probe, + .remove = cctrng_remove, +}; + +static int __init cctrng_mod_init(void) +{ + /* Compile time assertion checks */ + BUILD_BUG_ON(CCTRNG_DATA_BUF_WORDS < 6); + BUILD_BUG_ON((CCTRNG_DATA_BUF_WORDS & (CCTRNG_DATA_BUF_WORDS-1)) != 0); + + return platform_driver_register(&cctrng_driver); +} +module_init(cctrng_mod_init); + +static void __exit cctrng_mod_exit(void) +{ + platform_driver_unregister(&cctrng_driver); +} +module_exit(cctrng_mod_exit); + +/* Module description */ +MODULE_DESCRIPTION("ARM CryptoCell TRNG Driver"); +MODULE_AUTHOR("ARM"); +MODULE_LICENSE("GPL v2"); |