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From:   Vinod Koul <vkoul@kernel.org>
To:     linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org
Cc:     Bjorn Andersson <bjorn.andersson@linaro.org>,
        Matt Mackall <mpm@selenic.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-arm-msm@vger.kernel.org, Stephen Boyd <swboyd@chromium.org>,
        Timur Tabi <timur@codeaurora.org>,
        Vinod Koul <vkoul@kernel.org>
Subject: [PATCH v4 1/6] hwrng: remove msm hw_random driver
Date:   Wed,  4 Jul 2018 17:14:22 +0530
Message-Id: <20180704114427.29953-2-vkoul@kernel.org>
In-Reply-To: <20180704114427.29953-1-vkoul@kernel.org>
References: <20180704114427.29953-1-vkoul@kernel.org>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

This driver is for a pseudo-rng so should not be added in hwrng.
Remove it so that it's replacement can be added.

Signed-off-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/char/hw_random/Kconfig   |  13 ---
 drivers/char/hw_random/Makefile  |   1 -
 drivers/char/hw_random/msm-rng.c | 183 ---------------------------------------
 3 files changed, 197 deletions(-)
 delete mode 100644 drivers/char/hw_random/msm-rng.c

diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index c34b257d852d..dac895dc01b9 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -307,19 +307,6 @@ config HW_RANDOM_HISI
 
 	  If unsure, say Y.
 
-config HW_RANDOM_MSM
-	tristate "Qualcomm SoCs Random Number Generator support"
-	depends on HW_RANDOM && ARCH_QCOM
-	default HW_RANDOM
-	---help---
-	  This driver provides kernel-side support for the Random Number
-	  Generator hardware found on Qualcomm SoCs.
-
-	  To compile this driver as a module, choose M here. the
-	  module will be called msm-rng.
-
-	  If unsure, say Y.
-
 config HW_RANDOM_ST
 	tristate "ST Microelectronics HW Random Number Generator support"
 	depends on HW_RANDOM && ARCH_STI
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index 533e913c93d1..e35ec3ce3a20 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -29,7 +29,6 @@ obj-$(CONFIG_HW_RANDOM_POWERNV) += powernv-rng.o
 obj-$(CONFIG_HW_RANDOM_HISI)	+= hisi-rng.o
 obj-$(CONFIG_HW_RANDOM_BCM2835) += bcm2835-rng.o
 obj-$(CONFIG_HW_RANDOM_IPROC_RNG200) += iproc-rng200.o
-obj-$(CONFIG_HW_RANDOM_MSM) += msm-rng.o
 obj-$(CONFIG_HW_RANDOM_ST) += st-rng.o
 obj-$(CONFIG_HW_RANDOM_XGENE) += xgene-rng.o
 obj-$(CONFIG_HW_RANDOM_STM32) += stm32-rng.o
diff --git a/drivers/char/hw_random/msm-rng.c b/drivers/char/hw_random/msm-rng.c
deleted file mode 100644
index 841fee845ec9..000000000000
--- a/drivers/char/hw_random/msm-rng.c
+++ /dev/null
@@ -1,183 +0,0 @@
-/*
- * Copyright (c) 2011-2013, The Linux Foundation. All rights reserved.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 and
- * only version 2 as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- */
-#include <linux/clk.h>
-#include <linux/err.h>
-#include <linux/hw_random.h>
-#include <linux/io.h>
-#include <linux/module.h>
-#include <linux/of.h>
-#include <linux/platform_device.h>
-
-/* Device specific register offsets */
-#define PRNG_DATA_OUT		0x0000
-#define PRNG_STATUS		0x0004
-#define PRNG_LFSR_CFG		0x0100
-#define PRNG_CONFIG		0x0104
-
-/* Device specific register masks and config values */
-#define PRNG_LFSR_CFG_MASK	0x0000ffff
-#define PRNG_LFSR_CFG_CLOCKS	0x0000dddd
-#define PRNG_CONFIG_HW_ENABLE	BIT(1)
-#define PRNG_STATUS_DATA_AVAIL	BIT(0)
-
-#define MAX_HW_FIFO_DEPTH	16
-#define MAX_HW_FIFO_SIZE	(MAX_HW_FIFO_DEPTH * 4)
-#define WORD_SZ			4
-
-struct msm_rng {
-	void __iomem *base;
-	struct clk *clk;
-	struct hwrng hwrng;
-};
-
-#define to_msm_rng(p)	container_of(p, struct msm_rng, hwrng)
-
-static int msm_rng_enable(struct hwrng *hwrng, int enable)
-{
-	struct msm_rng *rng = to_msm_rng(hwrng);
-	u32 val;
-	int ret;
-
-	ret = clk_prepare_enable(rng->clk);
-	if (ret)
-		return ret;
-
-	if (enable) {
-		/* Enable PRNG only if it is not already enabled */
-		val = readl_relaxed(rng->base + PRNG_CONFIG);
-		if (val & PRNG_CONFIG_HW_ENABLE)
-			goto already_enabled;
-
-		val = readl_relaxed(rng->base + PRNG_LFSR_CFG);
-		val &= ~PRNG_LFSR_CFG_MASK;
-		val |= PRNG_LFSR_CFG_CLOCKS;
-		writel(val, rng->base + PRNG_LFSR_CFG);
-
-		val = readl_relaxed(rng->base + PRNG_CONFIG);
-		val |= PRNG_CONFIG_HW_ENABLE;
-		writel(val, rng->base + PRNG_CONFIG);
-	} else {
-		val = readl_relaxed(rng->base + PRNG_CONFIG);
-		val &= ~PRNG_CONFIG_HW_ENABLE;
-		writel(val, rng->base + PRNG_CONFIG);
-	}
-
-already_enabled:
-	clk_disable_unprepare(rng->clk);
-	return 0;
-}
-
-static int msm_rng_read(struct hwrng *hwrng, void *data, size_t max, bool wait)
-{
-	struct msm_rng *rng = to_msm_rng(hwrng);
-	size_t currsize = 0;
-	u32 *retdata = data;
-	size_t maxsize;
-	int ret;
-	u32 val;
-
-	/* calculate max size bytes to transfer back to caller */
-	maxsize = min_t(size_t, MAX_HW_FIFO_SIZE, max);
-
-	ret = clk_prepare_enable(rng->clk);
-	if (ret)
-		return ret;
-
-	/* read random data from hardware */
-	do {
-		val = readl_relaxed(rng->base + PRNG_STATUS);
-		if (!(val & PRNG_STATUS_DATA_AVAIL))
-			break;
-
-		val = readl_relaxed(rng->base + PRNG_DATA_OUT);
-		if (!val)
-			break;
-
-		*retdata++ = val;
-		currsize += WORD_SZ;
-
-		/* make sure we stay on 32bit boundary */
-		if ((maxsize - currsize) < WORD_SZ)
-			break;
-	} while (currsize < maxsize);
-
-	clk_disable_unprepare(rng->clk);
-
-	return currsize;
-}
-
-static int msm_rng_init(struct hwrng *hwrng)
-{
-	return msm_rng_enable(hwrng, 1);
-}
-
-static void msm_rng_cleanup(struct hwrng *hwrng)
-{
-	msm_rng_enable(hwrng, 0);
-}
-
-static int msm_rng_probe(struct platform_device *pdev)
-{
-	struct resource *res;
-	struct msm_rng *rng;
-	int ret;
-
-	rng = devm_kzalloc(&pdev->dev, sizeof(*rng), GFP_KERNEL);
-	if (!rng)
-		return -ENOMEM;
-
-	platform_set_drvdata(pdev, rng);
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	rng->base = devm_ioremap_resource(&pdev->dev, res);
-	if (IS_ERR(rng->base))
-		return PTR_ERR(rng->base);
-
-	rng->clk = devm_clk_get(&pdev->dev, "core");
-	if (IS_ERR(rng->clk))
-		return PTR_ERR(rng->clk);
-
-	rng->hwrng.name = KBUILD_MODNAME,
-	rng->hwrng.init = msm_rng_init,
-	rng->hwrng.cleanup = msm_rng_cleanup,
-	rng->hwrng.read = msm_rng_read,
-
-	ret = devm_hwrng_register(&pdev->dev, &rng->hwrng);
-	if (ret) {
-		dev_err(&pdev->dev, "failed to register hwrng\n");
-		return ret;
-	}
-
-	return 0;
-}
-
-static const struct of_device_id msm_rng_of_match[] = {
-	{ .compatible = "qcom,prng", },
-	{}
-};
-MODULE_DEVICE_TABLE(of, msm_rng_of_match);
-
-static struct platform_driver msm_rng_driver = {
-	.probe = msm_rng_probe,
-	.driver = {
-		.name = KBUILD_MODNAME,
-		.of_match_table = of_match_ptr(msm_rng_of_match),
-	}
-};
-module_platform_driver(msm_rng_driver);
-
-MODULE_ALIAS("platform:" KBUILD_MODNAME);
-MODULE_AUTHOR("The Linux Foundation");
-MODULE_DESCRIPTION("Qualcomm MSM random number generator driver");
-MODULE_LICENSE("GPL v2");
-- 
2.14.4