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	Usage of common.h is deprecated. * Remove common.h from RNG drivers. * Sort includes. * Add time.h to sandbox driver. * Add linux/types.h to rng.h to provide size_t. Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
		
			
				
	
	
		
			143 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			143 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0+
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| /*
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|  * PRNG driver for Qualcomm IPQ40xx
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|  *
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|  * Copyright (c) 2020 Sartura Ltd.
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|  *
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|  * Author: Robert Marko <robert.marko@sartura.hr>
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|  *
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|  * Based on Linux driver
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|  */
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| 
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| #include <clk.h>
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| #include <dm.h>
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| #include <rng.h>
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| #include <asm/io.h>
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| #include <linux/bitops.h>
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| 
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| /* Device specific register offsets */
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| #define PRNG_DATA_OUT		0x0000
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| #define PRNG_STATUS			0x0004
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| #define PRNG_LFSR_CFG		0x0100
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| #define PRNG_CONFIG			0x0104
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| 
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| /* Device specific register masks and config values */
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| #define PRNG_LFSR_CFG_MASK		0x0000ffff
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| #define PRNG_LFSR_CFG_CLOCKS	0x0000dddd
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| #define PRNG_CONFIG_HW_ENABLE	BIT(1)
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| #define PRNG_STATUS_DATA_AVAIL	BIT(0)
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| 
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| #define MAX_HW_FIFO_DEPTH		16
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| #define MAX_HW_FIFO_SIZE		(MAX_HW_FIFO_DEPTH * 4)
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| #define WORD_SZ					4
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| 
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| struct msm_rng_priv {
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| 	phys_addr_t base;
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| 	struct clk clk;
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| };
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| 
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| static int msm_rng_read(struct udevice *dev, void *data, size_t len)
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| {
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| 	struct msm_rng_priv *priv = dev_get_priv(dev);
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| 	size_t currsize = 0;
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| 	u32 *retdata = data;
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| 	size_t maxsize;
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| 	u32 val;
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| 
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| 	/* calculate max size bytes to transfer back to caller */
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| 	maxsize = min_t(size_t, MAX_HW_FIFO_SIZE, len);
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| 
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| 	/* read random data from hardware */
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| 	do {
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| 		val = readl_relaxed(priv->base + PRNG_STATUS);
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| 		if (!(val & PRNG_STATUS_DATA_AVAIL))
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| 			break;
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| 
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| 		val = readl_relaxed(priv->base + PRNG_DATA_OUT);
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| 		if (!val)
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| 			break;
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| 
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| 		*retdata++ = val;
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| 		currsize += WORD_SZ;
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| 
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| 		/* make sure we stay on 32bit boundary */
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| 		if ((maxsize - currsize) < WORD_SZ)
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| 			break;
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| 	} while (currsize < maxsize);
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| 
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| 	return 0;
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| }
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| 
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| static int msm_rng_enable(struct msm_rng_priv *priv, int enable)
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| {
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| 	u32 val;
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| 
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| 	if (enable) {
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| 		/* Enable PRNG only if it is not already enabled */
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| 		val = readl_relaxed(priv->base + PRNG_CONFIG);
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| 		if (val & PRNG_CONFIG_HW_ENABLE) {
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| 			val = readl_relaxed(priv->base + PRNG_LFSR_CFG);
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| 			val &= ~PRNG_LFSR_CFG_MASK;
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| 			val |= PRNG_LFSR_CFG_CLOCKS;
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| 			writel(val, priv->base + PRNG_LFSR_CFG);
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| 
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| 			val = readl_relaxed(priv->base + PRNG_CONFIG);
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| 			val |= PRNG_CONFIG_HW_ENABLE;
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| 			writel(val, priv->base + PRNG_CONFIG);
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| 		}
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| 	} else {
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| 		val = readl_relaxed(priv->base + PRNG_CONFIG);
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| 		val &= ~PRNG_CONFIG_HW_ENABLE;
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| 		writel(val, priv->base + PRNG_CONFIG);
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| 	}
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| 
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| 	return 0;
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| }
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| 
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| static int msm_rng_probe(struct udevice *dev)
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| {
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| 	struct msm_rng_priv *priv = dev_get_priv(dev);
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| 
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| 	int ret;
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| 
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| 	priv->base = dev_read_addr(dev);
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| 	if (priv->base == FDT_ADDR_T_NONE)
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| 		return -EINVAL;
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| 
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| 	ret = clk_get_by_index(dev, 0, &priv->clk);
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| 	if (ret)
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| 		return ret;
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| 
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| 	ret = clk_enable(&priv->clk);
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| 	if (ret < 0)
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| 		return ret;
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| 
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| 	return msm_rng_enable(priv, 1);
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| }
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| 
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| static int msm_rng_remove(struct udevice *dev)
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| {
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| 	struct msm_rng_priv *priv = dev_get_priv(dev);
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| 
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| 	return msm_rng_enable(priv, 0);
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| }
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| 
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| static const struct dm_rng_ops msm_rng_ops = {
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| 	.read = msm_rng_read,
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| };
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| 
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| static const struct udevice_id msm_rng_match[] = {
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| 	{ .compatible = "qcom,prng", },
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| 	{},
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| };
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| 
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| U_BOOT_DRIVER(msm_rng) = {
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| 	.name = "msm-rng",
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| 	.id = UCLASS_RNG,
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| 	.of_match = msm_rng_match,
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| 	.ops = &msm_rng_ops,
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| 	.probe = msm_rng_probe,
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| 	.remove = msm_rng_remove,
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| 	.priv_auto	= sizeof(struct msm_rng_priv),
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| };
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