--- /dev/null
+/*
+ * RNG driver for Freescale RNGC
+ *
+ * Copyright (C) 2008-2011 Freescale Semiconductor, Inc.
+ */
+
+/*
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+/*
+ * Hardware driver for the Intel/AMD/VIA Random Number Generators (RNG)
+ * (c) Copyright 2003 Red Hat Inc <jgarzik@redhat.com>
+ *
+ * derived from
+ *
+ * Hardware driver for the AMD 768 Random Number Generator (RNG)
+ * (c) Copyright 2001 Red Hat Inc <alan@redhat.com>
+ *
+ * derived from
+ *
+ * Hardware driver for Intel i810 Random Number Generator (RNG)
+ * Copyright 2000,2001 Jeff Garzik <jgarzik@pobox.com>
+ * Copyright 2000,2001 Philipp Rumpf <prumpf@mandrakesoft.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/hw_random.h>
+#include <linux/io.h>
+
+#define RNGC_VERSION_MAJOR3 3
+
+#define RNGC_VERSION_ID 0x0000
+#define RNGC_COMMAND 0x0004
+#define RNGC_CONTROL 0x0008
+#define RNGC_STATUS 0x000C
+#define RNGC_ERROR 0x0010
+#define RNGC_FIFO 0x0014
+#define RNGC_VERIF_CTRL 0x0020
+#define RNGC_OSC_CTRL_COUNT 0x0028
+#define RNGC_OSC_COUNT 0x002C
+#define RNGC_OSC_COUNT_STATUS 0x0030
+
+#define RNGC_VERID_ZEROS_MASK 0x0f000000
+#define RNGC_VERID_RNG_TYPE_MASK 0xf0000000
+#define RNGC_VERID_RNG_TYPE_SHIFT 28
+#define RNGC_VERID_CHIP_VERSION_MASK 0x00ff0000
+#define RNGC_VERID_CHIP_VERSION_SHIFT 16
+#define RNGC_VERID_VERSION_MAJOR_MASK 0x0000ff00
+#define RNGC_VERID_VERSION_MAJOR_SHIFT 8
+#define RNGC_VERID_VERSION_MINOR_MASK 0x000000ff
+#define RNGC_VERID_VERSION_MINOR_SHIFT 0
+
+#define RNGC_CMD_ZEROS_MASK 0xffffff8c
+#define RNGC_CMD_SW_RST 0x00000040
+#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_CTRL_ZEROS_MASK 0xfffffc8c
+#define RNGC_CTRL_CTL_ACC 0x00000200
+#define RNGC_CTRL_VERIF_MODE 0x00000100
+#define RNGC_CTRL_MASK_ERROR 0x00000040
+
+#define RNGC_CTRL_MASK_DONE 0x00000020
+#define RNGC_CTRL_AUTO_SEED 0x00000010
+#define RNGC_CTRL_FIFO_UFLOW_MASK 0x00000003
+#define RNGC_CTRL_FIFO_UFLOW_SHIFT 0
+
+#define RNGC_CTRL_FIFO_UFLOW_ZEROS_ERROR 0
+#define RNGC_CTRL_FIFO_UFLOW_ZEROS_ERROR2 1
+#define RNGC_CTRL_FIFO_UFLOW_BUS_XFR 2
+#define RNGC_CTRL_FIFO_UFLOW_ZEROS_INTR 3
+
+#define RNGC_STATUS_ST_PF_MASK 0x00c00000
+#define RNGC_STATUS_ST_PF_SHIFT 22
+#define RNGC_STATUS_ST_PF_TRNG 0x00800000
+#define RNGC_STATUS_ST_PF_PRNG 0x00400000
+#define RNGC_STATUS_ERROR 0x00010000
+#define RNGC_STATUS_FIFO_SIZE_MASK 0x0000f000
+#define RNGC_STATUS_FIFO_SIZE_SHIFT 12
+#define RNGC_STATUS_FIFO_LEVEL_MASK 0x00000f00
+#define RNGC_STATUS_FIFO_LEVEL_SHIFT 8
+#define RNGC_STATUS_NEXT_SEED_DONE 0x00000040
+#define RNGC_STATUS_SEED_DONE 0x00000020
+#define RNGC_STATUS_ST_DONE 0x00000010
+#define RNGC_STATUS_RESEED 0x00000008
+#define RNGC_STATUS_SLEEP 0x00000004
+#define RNGC_STATUS_BUSY 0x00000002
+#define RNGC_STATUS_SEC_STATE 0x00000001
+
+#define RNGC_ERROR_STATUS_ZEROS_MASK 0xffffffc0
+#define RNGC_ERROR_STATUS_BAD_KEY 0x00000040
+#define RNGC_ERROR_STATUS_RAND_ERR 0x00000020
+#define RNGC_ERROR_STATUS_FIFO_ERR 0x00000010
+#define RNGC_ERROR_STATUS_STAT_ERR 0x00000008
+#define RNGC_ERROR_STATUS_ST_ERR 0x00000004
+#define RNGC_ERROR_STATUS_OSC_ERR 0x00000002
+#define RNGC_ERROR_STATUS_LFSR_ERR 0x00000001
+
+#define RNG_ADDR_RANGE 0x34
+
+static DECLARE_COMPLETION(rng_self_testing);
+static DECLARE_COMPLETION(rng_seed_done);
+
+static struct platform_device *rng_dev;
+
+int irq_rng;
+
+static int fsl_rngc_data_present(struct hwrng *rng)
+{
+ int level;
+ u32 rngc_base = (u32) rng->priv;
+
+ /* how many random numbers are in FIFO? [0-16] */
+ level = (__raw_readl(rngc_base + RNGC_STATUS) &
+ RNGC_STATUS_FIFO_LEVEL_MASK) >> RNGC_STATUS_FIFO_LEVEL_SHIFT;
+
+ return level > 0 ? 1 : 0;
+}
+
+static int fsl_rngc_data_read(struct hwrng *rng, u32 * data)
+{
+ int err;
+ u32 rngc_base = (u32) rng->priv;
+
+ /* retrieve a random number from FIFO */
+ *data = __raw_readl(rngc_base + RNGC_FIFO);
+
+ /* is there some error while reading this random number? */
+ err = __raw_readl(rngc_base + RNGC_STATUS) & RNGC_STATUS_ERROR;
+
+ /* if error happened doesn't return random number */
+ return err ? 0 : 4;
+}
+
+static irqreturn_t rngc_irq(int irq, void *dev)
+{
+ int handled = 0;
+ u32 rngc_base = (u32) dev;
+
+ /* is the seed creation done? */
+ if (__raw_readl(rngc_base + RNGC_STATUS) & RNGC_STATUS_SEED_DONE) {
+ complete(&rng_seed_done);
+ __raw_writel(RNGC_CMD_CLR_INT | RNGC_CMD_CLR_ERR,
+ rngc_base + RNGC_COMMAND);
+ handled = 1;
+ }
+
+ /* is the self test done? */
+ if (__raw_readl(rngc_base + RNGC_STATUS) & RNGC_STATUS_ST_DONE) {
+ complete(&rng_self_testing);
+ __raw_writel(RNGC_CMD_CLR_INT | RNGC_CMD_CLR_ERR,
+ rngc_base + RNGC_COMMAND);
+ handled = 1;
+ }
+
+ /* is there any error? */
+ if (__raw_readl(rngc_base + RNGC_STATUS) & RNGC_STATUS_ERROR) {
+ /* clear interrupt */
+ __raw_writel(RNGC_CMD_CLR_INT | RNGC_CMD_CLR_ERR,
+ rngc_base + RNGC_COMMAND);
+ handled = 1;
+ }
+
+ return handled;
+}
+
+static int fsl_rngc_init(struct hwrng *rng)
+{
+ int err;
+ u32 cmd, ctrl, osc, rngc_base = (u32) rng->priv;
+
+ INIT_COMPLETION(rng_self_testing);
+ INIT_COMPLETION(rng_seed_done);
+
+ err = __raw_readl(rngc_base + RNGC_STATUS) & RNGC_STATUS_ERROR;
+ if (err) {
+ /* is this a bad keys error ? */
+ if (__raw_readl(rngc_base + RNGC_ERROR) &
+ RNGC_ERROR_STATUS_BAD_KEY) {
+ dev_err(&rng_dev->dev, "Can't start, Bad Keys.\n");
+ return -EIO;
+ }
+ }
+
+ /* mask all interrupts, will be unmasked soon */
+ ctrl = __raw_readl(rngc_base + RNGC_CONTROL);
+ __raw_writel(ctrl | RNGC_CTRL_MASK_DONE | RNGC_CTRL_MASK_ERROR,
+ rngc_base + RNGC_CONTROL);
+
+ /* verify if oscillator is working */
+ osc = __raw_readl(rngc_base + RNGC_ERROR);
+ if (osc & RNGC_ERROR_STATUS_OSC_ERR) {
+ dev_err(&rng_dev->dev, "RNGC Oscillator is dead!\n");
+ return -EIO;
+ }
+
+ err = request_irq(irq_rng, rngc_irq, 0, "fsl_rngc", (void *)rng->priv);
+ if (err) {
+ dev_err(&rng_dev->dev, "Can't get interrupt working.\n");
+ return -EIO;
+ }
+
+ /* do self test, repeat until get success */
+ do {
+ /* clear error */
+ cmd = __raw_readl(rngc_base + RNGC_COMMAND);
+ __raw_writel(cmd | RNGC_CMD_CLR_ERR, rngc_base + RNGC_COMMAND);
+
+ /* unmask all interrupt */
+ ctrl = __raw_readl(rngc_base + RNGC_CONTROL);
+ __raw_writel(ctrl & ~(RNGC_CTRL_MASK_DONE |
+ RNGC_CTRL_MASK_ERROR), rngc_base + RNGC_CONTROL);
+
+ /* run self test */
+ cmd = __raw_readl(rngc_base + RNGC_COMMAND);
+ __raw_writel(cmd | RNGC_CMD_SELF_TEST,
+ rngc_base + RNGC_COMMAND);
+
+ wait_for_completion(&rng_self_testing);
+
+ } while (__raw_readl(rngc_base + RNGC_ERROR) &
+ RNGC_ERROR_STATUS_ST_ERR);
+
+ /* clear interrupt. Is it really necessary here? */
+ __raw_writel(RNGC_CMD_CLR_INT | RNGC_CMD_CLR_ERR,
+ rngc_base + RNGC_COMMAND);
+
+ /* create seed, repeat while there is some statistical error */
+ do {
+ /* clear error */
+ cmd = __raw_readl(rngc_base + RNGC_COMMAND);
+ __raw_writel(cmd | RNGC_CMD_CLR_ERR, rngc_base + RNGC_COMMAND);
+
+ /* seed creation */
+ cmd = __raw_readl(rngc_base + RNGC_COMMAND);
+ __raw_writel(cmd | RNGC_CMD_SEED, rngc_base + RNGC_COMMAND);
+
+ wait_for_completion(&rng_seed_done);
+
+ } while (__raw_readl(rngc_base + RNGC_ERROR) &
+ RNGC_ERROR_STATUS_STAT_ERR);
+
+ err = __raw_readl(rngc_base + RNGC_ERROR) &
+ (RNGC_ERROR_STATUS_STAT_ERR |
+ RNGC_ERROR_STATUS_RAND_ERR |
+ RNGC_ERROR_STATUS_FIFO_ERR |
+ RNGC_ERROR_STATUS_ST_ERR |
+ RNGC_ERROR_STATUS_OSC_ERR |
+ RNGC_ERROR_STATUS_LFSR_ERR);
+
+ if (err) {
+ dev_err(&rng_dev->dev, "FSL RNGC appears inoperable.\n");
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static struct hwrng fsl_rngc = {
+ .name = "fsl-rngc",
+ .init = fsl_rngc_init,
+ .data_present = fsl_rngc_data_present,
+ .data_read = fsl_rngc_data_read
+};
+
+static int __init fsl_rngc_probe(struct platform_device *pdev)
+{
+ int err = -ENODEV;
+ struct clk *clk;
+ struct resource *res, *mem;
+ void __iomem *rngc_base = NULL;
+
+ if (rng_dev)
+ return -EBUSY;
+
+ clk = clk_get(&pdev->dev, "rng_clk");
+
+ if (IS_ERR(clk)) {
+ dev_err(&pdev->dev, "Can not get rng_clk\n");
+ err = PTR_ERR(clk);
+ return err;
+ }
+
+ clk_enable(clk);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+ if (!res)
+ return -ENOENT;
+
+ mem = request_mem_region(res->start, res->end - res->start, pdev->name);
+
+ if (mem == NULL)
+ return -EBUSY;
+
+ dev_set_drvdata(&pdev->dev, mem);
+ rngc_base = ioremap(res->start, res->end - res->start);
+
+ fsl_rngc.priv = (unsigned long)rngc_base;
+
+ irq_rng = platform_get_irq(pdev, 0);
+
+ err = hwrng_register(&fsl_rngc);
+ if (err) {
+ dev_err(&pdev->dev, "FSL RNGC registering failed (%d)\n", err);
+ return err;
+ }
+
+ rng_dev = pdev;
+
+ dev_info(&pdev->dev, "FSL RNGC Registered.\n");
+
+ return 0;
+}
+
+static int __exit fsl_rngc_remove(struct platform_device *pdev)
+{
+ struct clk *clk;
+ struct resource *mem = dev_get_drvdata(&pdev->dev);
+ void __iomem *rngc_base = (void __iomem *)fsl_rngc.priv;
+
+ clk = clk_get(&pdev->dev, "rng_clk");
+
+ if (IS_ERR(clk))
+ dev_err(&pdev->dev, "Can not get rng_clk\n");
+ else
+ clk_disable(clk);
+
+ hwrng_unregister(&fsl_rngc);
+
+ release_resource(mem);
+
+ iounmap(rngc_base);
+
+ return 0;
+}
+
+static int fsl_rngc_suspend(struct platform_device *pdev,
+ pm_message_t state)
+{
+#ifdef CONFIG_PM
+ struct clk *clk = clk_get(&pdev->dev, "rng_clk");
+
+ if (IS_ERR(clk)) {
+ dev_err(&pdev->dev, "Can not get rng_clk\n");
+ return PTR_ERR(clk);
+ }
+
+ clk_disable(clk);
+#endif
+
+ return 0;
+}
+
+static int fsl_rngc_resume(struct platform_device *pdev)
+{
+#ifdef CONFIG_PM
+ struct clk *clk = clk_get(&pdev->dev, "rng_clk");
+
+ if (IS_ERR(clk)) {
+ dev_err(&pdev->dev, "Can not get rng_clk\n");
+ return PTR_ERR(clk);
+ }
+
+ clk_enable(clk);
+#endif
+
+ return 0;
+}
+
+static struct platform_driver fsl_rngc_driver = {
+ .driver = {
+ .name = "fsl_rngc",
+ .owner = THIS_MODULE,
+ },
+ .remove = __exit_p(fsl_rngc_remove),
+ .suspend = fsl_rngc_suspend,
+ .resume = fsl_rngc_resume,
+};
+
+static int __init mod_init(void)
+{
+ return platform_driver_probe(&fsl_rngc_driver, fsl_rngc_probe);
+}
+
+static void __exit mod_exit(void)
+{
+ platform_driver_unregister(&fsl_rngc_driver);
+}
+
+module_init(mod_init);
+module_exit(mod_exit);
+
+MODULE_AUTHOR("Freescale Semiconductor, Inc.");
+MODULE_DESCRIPTION("H/W RNGC driver for i.MX");
+MODULE_LICENSE("GPL");
projects / karo-tx-linux.git / commitdiff