[PATCH 07/10] char: hw_random: Remove tx4939 driver

[Thomas Bogendoerfer <tsbogend@alpha.franken.de>]

CPU support for TX49xx is getting removed, so remove hw_random driver
for it.

Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
---
 drivers/char/hw_random/Kconfig      |  13 ---
 drivers/char/hw_random/Makefile     |   1 -
 drivers/char/hw_random/tx4939-rng.c | 157 ----------------------------
 3 files changed, 171 deletions(-)
 delete mode 100644 drivers/char/hw_random/tx4939-rng.c

diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 1fe006f3f12f..9d13d640384a 100644
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -226,19 +226,6 @@ config HW_RANDOM_VIRTIO
 	  To compile this driver as a module, choose M here: the
 	  module will be called virtio-rng.  If unsure, say N.
 
-config HW_RANDOM_TX4939
-	tristate "TX4939 Random Number Generator support"
-	depends on SOC_TX4939
-	default HW_RANDOM
-	help
-	  This driver provides kernel-side support for the Random Number
-	  Generator hardware found on TX4939 SoC.
-
-	  To compile this driver as a module, choose M here: the
-	  module will be called tx4939-rng.
-
-	  If unsure, say Y.
-
 config HW_RANDOM_MXC_RNGA
 	tristate "Freescale i.MX RNGA Random Number Generator"
 	depends on SOC_IMX31
diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile
index 8933fada74f2..b2aa37162e24 100644
--- a/drivers/char/hw_random/Makefile
+++ b/drivers/char/hw_random/Makefile
@@ -20,7 +20,6 @@ obj-$(CONFIG_HW_RANDOM_OMAP) += omap-rng.o
 obj-$(CONFIG_HW_RANDOM_OMAP3_ROM) += omap3-rom-rng.o
 obj-$(CONFIG_HW_RANDOM_PASEMI) += pasemi-rng.o
 obj-$(CONFIG_HW_RANDOM_VIRTIO) += virtio-rng.o
-obj-$(CONFIG_HW_RANDOM_TX4939) += tx4939-rng.o
 obj-$(CONFIG_HW_RANDOM_MXC_RNGA) += mxc-rnga.o
 obj-$(CONFIG_HW_RANDOM_IMX_RNGC) += imx-rngc.o
 obj-$(CONFIG_HW_RANDOM_INGENIC_RNG) += ingenic-rng.o
diff --git a/drivers/char/hw_random/tx4939-rng.c b/drivers/char/hw_random/tx4939-rng.c
deleted file mode 100644
index c8bd34e740fd..000000000000
--- a/drivers/char/hw_random/tx4939-rng.c
+++ /dev/null
@@ -1,157 +0,0 @@
-/*
- * RNG driver for TX4939 Random Number Generators (RNG)
- *
- * Copyright (C) 2009 Atsushi Nemoto <anemo@mba.ocn.ne.jp>
- *
- * This file is subject to the terms and conditions of the GNU General Public
- * License.  See the file "COPYING" in the main directory of this archive
- * for more details.
- */
-#include <linux/err.h>
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/delay.h>
-#include <linux/io.h>
-#include <linux/platform_device.h>
-#include <linux/hw_random.h>
-#include <linux/gfp.h>
-
-#define TX4939_RNG_RCSR		0x00000000
-#define TX4939_RNG_ROR(n)	(0x00000018 + (n) * 8)
-
-#define TX4939_RNG_RCSR_INTE	0x00000008
-#define TX4939_RNG_RCSR_RST	0x00000004
-#define TX4939_RNG_RCSR_FIN	0x00000002
-#define TX4939_RNG_RCSR_ST	0x00000001
-
-struct tx4939_rng {
-	struct hwrng rng;
-	void __iomem *base;
-	u64 databuf[3];
-	unsigned int data_avail;
-};
-
-static void rng_io_start(void)
-{
-#ifndef CONFIG_64BIT
-	/*
-	 * readq is reading a 64-bit register using a 64-bit load.  On
-	 * a 32-bit kernel however interrupts or any other processor
-	 * exception would clobber the upper 32-bit of the processor
-	 * register so interrupts need to be disabled.
-	 */
-	local_irq_disable();
-#endif
-}
-
-static void rng_io_end(void)
-{
-#ifndef CONFIG_64BIT
-	local_irq_enable();
-#endif
-}
-
-static u64 read_rng(void __iomem *base, unsigned int offset)
-{
-	return ____raw_readq(base + offset);
-}
-
-static void write_rng(u64 val, void __iomem *base, unsigned int offset)
-{
-	return ____raw_writeq(val, base + offset);
-}
-
-static int tx4939_rng_data_present(struct hwrng *rng, int wait)
-{
-	struct tx4939_rng *rngdev = container_of(rng, struct tx4939_rng, rng);
-	int i;
-
-	if (rngdev->data_avail)
-		return rngdev->data_avail;
-	for (i = 0; i < 20; i++) {
-		rng_io_start();
-		if (!(read_rng(rngdev->base, TX4939_RNG_RCSR)
-		      & TX4939_RNG_RCSR_ST)) {
-			rngdev->databuf[0] =
-				read_rng(rngdev->base, TX4939_RNG_ROR(0));
-			rngdev->databuf[1] =
-				read_rng(rngdev->base, TX4939_RNG_ROR(1));
-			rngdev->databuf[2] =
-				read_rng(rngdev->base, TX4939_RNG_ROR(2));
-			rngdev->data_avail =
-				sizeof(rngdev->databuf) / sizeof(u32);
-			/* Start RNG */
-			write_rng(TX4939_RNG_RCSR_ST,
-				  rngdev->base, TX4939_RNG_RCSR);
-			wait = 0;
-		}
-		rng_io_end();
-		if (!wait)
-			break;
-		/* 90 bus clock cycles by default for generation */
-		ndelay(90 * 5);
-	}
-	return rngdev->data_avail;
-}
-
-static int tx4939_rng_data_read(struct hwrng *rng, u32 *buffer)
-{
-	struct tx4939_rng *rngdev = container_of(rng, struct tx4939_rng, rng);
-
-	rngdev->data_avail--;
-	*buffer = *((u32 *)&rngdev->databuf + rngdev->data_avail);
-	return sizeof(u32);
-}
-
-static int __init tx4939_rng_probe(struct platform_device *dev)
-{
-	struct tx4939_rng *rngdev;
-	int i;
-
-	rngdev = devm_kzalloc(&dev->dev, sizeof(*rngdev), GFP_KERNEL);
-	if (!rngdev)
-		return -ENOMEM;
-	rngdev->base = devm_platform_ioremap_resource(dev, 0);
-	if (IS_ERR(rngdev->base))
-		return PTR_ERR(rngdev->base);
-
-	rngdev->rng.name = dev_name(&dev->dev);
-	rngdev->rng.data_present = tx4939_rng_data_present;
-	rngdev->rng.data_read = tx4939_rng_data_read;
-
-	rng_io_start();
-	/* Reset RNG */
-	write_rng(TX4939_RNG_RCSR_RST, rngdev->base, TX4939_RNG_RCSR);
-	write_rng(0, rngdev->base, TX4939_RNG_RCSR);
-	/* Start RNG */
-	write_rng(TX4939_RNG_RCSR_ST, rngdev->base, TX4939_RNG_RCSR);
-	rng_io_end();
-	/*
-	 * Drop first two results.  From the datasheet:
-	 * The quality of the random numbers generated immediately
-	 * after reset can be insufficient.  Therefore, do not use
-	 * random numbers obtained from the first and second
-	 * generations; use the ones from the third or subsequent
-	 * generation.
-	 */
-	for (i = 0; i < 2; i++) {
-		rngdev->data_avail = 0;
-		if (!tx4939_rng_data_present(&rngdev->rng, 1))
-			return -EIO;
-	}
-
-	platform_set_drvdata(dev, rngdev);
-	return devm_hwrng_register(&dev->dev, &rngdev->rng);
-}
-
-static struct platform_driver tx4939_rng_driver = {
-	.driver		= {
-		.name	= "tx4939-rng",
-	},
-};
-
-module_platform_driver_probe(tx4939_rng_driver, tx4939_rng_probe);
-
-MODULE_DESCRIPTION("H/W Random Number Generator (RNG) driver for TX4939");
-MODULE_LICENSE("GPL");
-- 
2.29.2