hwrng: omap - Add device variant for SafeXcel IP-76 found in Armada 8K

This commits adds a device variant for Safexcel,EIP76 found in Marvell
Armada 8k. It defines registers mapping with the good offset and add a
specific initialization function.

Signed-off-by: Romain Perier <romain.perier@free-electrons.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig
index 200dab5136a7f99576fffcb440edc7eedfa71e78..ceff2fc524b1a784204bf188351be7a70c5ad6a3 100644 (file)
--- a/drivers/char/hw_random/Kconfig
+++ b/drivers/char/hw_random/Kconfig
@@ -168,7 +168,7 @@ config HW_RANDOM_IXP4XX
 
 config HW_RANDOM_OMAP
        tristate "OMAP Random Number Generator support"
-       depends on ARCH_OMAP16XX || ARCH_OMAP2PLUS
+       depends on ARCH_OMAP16XX || ARCH_OMAP2PLUS || ARCH_MVEBU
        default HW_RANDOM
        ---help---
          This driver provides kernel-side support for the Random Number

diff --git a/drivers/char/hw_random/omap-rng.c b/drivers/char/hw_random/omap-rng.c
index c64a0990feb753945de3fb6eb011a8fc7bf93697..3ad86fdf954e96a71b16f436f2b22bd02e6cbd8f 100644 (file)
--- a/drivers/char/hw_random/omap-rng.c
+++ b/drivers/char/hw_random/omap-rng.c
@@ -28,6 +28,7 @@
 #include <linux/of_device.h>
 #include <linux/of_address.h>
 #include <linux/interrupt.h>
+#include <linux/clk.h>
 
 #include <asm/io.h>
 
@@ -63,6 +64,7 @@
 
 #define OMAP2_RNG_OUTPUT_SIZE                  0x4
 #define OMAP4_RNG_OUTPUT_SIZE                  0x8
+#define EIP76_RNG_OUTPUT_SIZE                  0x10
 
 enum {
        RNG_OUTPUT_0_REG = 0,
@@ -108,6 +110,23 @@ static const u16 reg_map_omap4[] = {
        [RNG_SYSCONFIG_REG]     = 0x1FE4,
 };
 
+static const u16 reg_map_eip76[] = {
+       [RNG_OUTPUT_0_REG]      = 0x0,
+       [RNG_OUTPUT_1_REG]      = 0x4,
+       [RNG_OUTPUT_2_REG]      = 0x8,
+       [RNG_OUTPUT_3_REG]      = 0xc,
+       [RNG_STATUS_REG]        = 0x10,
+       [RNG_INTACK_REG]        = 0x10,
+       [RNG_CONTROL_REG]       = 0x14,
+       [RNG_CONFIG_REG]        = 0x18,
+       [RNG_ALARMCNT_REG]      = 0x1c,
+       [RNG_FROENABLE_REG]     = 0x20,
+       [RNG_FRODETUNE_REG]     = 0x24,
+       [RNG_ALARMMASK_REG]     = 0x28,
+       [RNG_ALARMSTOP_REG]     = 0x2c,
+       [RNG_REV_REG]           = 0x7c,
+};
+
 struct omap_rng_dev;
 /**
  * struct omap_rng_pdata - RNG IP block-specific data
@@ -130,6 +149,7 @@ struct omap_rng_dev {
        struct device                   *dev;
        const struct omap_rng_pdata     *pdata;
        struct hwrng rng;
+       struct clk                      *clk;
 };
 
 static inline u32 omap_rng_read(struct omap_rng_dev *priv, u16 reg)
@@ -221,6 +241,38 @@ static inline u32 omap4_rng_data_present(struct omap_rng_dev *priv)
        return omap_rng_read(priv, RNG_STATUS_REG) & RNG_REG_STATUS_RDY;
 }
 
+static int eip76_rng_init(struct omap_rng_dev *priv)
+{
+       u32 val;
+
+       /* Return if RNG is already running. */
+       if (omap_rng_read(priv, RNG_CONTROL_REG) & RNG_CONTROL_ENABLE_TRNG_MASK)
+               return 0;
+
+       /*  Number of 512 bit blocks of raw Noise Source output data that must
+        *  be processed by either the Conditioning Function or the
+        *  SP 800-90 DRBG ‘BC_DF’ functionality to yield a ‘full entropy’
+        *  output value.
+        */
+       val = 0x5 << RNG_CONFIG_MIN_REFIL_CYCLES_SHIFT;
+
+       /* Number of FRO samples that are XOR-ed together into one bit to be
+        * shifted into the main shift register
+        */
+       val |= RNG_CONFIG_MAX_REFIL_CYCLES << RNG_CONFIG_MAX_REFIL_CYCLES_SHIFT;
+       omap_rng_write(priv, RNG_CONFIG_REG, val);
+
+       /* Enable all available FROs */
+       omap_rng_write(priv, RNG_FRODETUNE_REG, 0x0);
+       omap_rng_write(priv, RNG_FROENABLE_REG, RNG_REG_FROENABLE_MASK);
+
+       /* Enable TRNG */
+       val = RNG_CONTROL_ENABLE_TRNG_MASK;
+       omap_rng_write(priv, RNG_CONTROL_REG, val);
+
+       return 0;
+}
+
 static int omap4_rng_init(struct omap_rng_dev *priv)
 {
        u32 val;
@@ -290,6 +342,14 @@ static struct omap_rng_pdata omap4_rng_pdata = {
        .cleanup        = omap4_rng_cleanup,
 };
 
+static struct omap_rng_pdata eip76_rng_pdata = {
+       .regs           = (u16 *)reg_map_eip76,
+       .data_size      = EIP76_RNG_OUTPUT_SIZE,
+       .data_present   = omap4_rng_data_present,
+       .init           = eip76_rng_init,
+       .cleanup        = omap4_rng_cleanup,
+};
+
 static const struct of_device_id omap_rng_of_match[] = {
                {
                        .compatible     = "ti,omap2-rng",
@@ -299,6 +359,10 @@ static const struct of_device_id omap_rng_of_match[] = {
                        .compatible     = "ti,omap4-rng",
                        .data           = &omap4_rng_pdata,
                },
+               {
+                       .compatible     = "inside-secure,safexcel-eip76",
+                       .data           = &eip76_rng_pdata,
+               },
                {},
 };
 MODULE_DEVICE_TABLE(of, omap_rng_of_match);
@@ -317,7 +381,8 @@ static int of_get_omap_rng_device_details(struct omap_rng_dev *priv,
        }
        priv->pdata = match->data;
 
-       if (of_device_is_compatible(dev->of_node, "ti,omap4-rng")) {
+       if (of_device_is_compatible(dev->of_node, "ti,omap4-rng") ||
+           of_device_is_compatible(dev->of_node, "inside-secure,safexcel-eip76")) {
                irq = platform_get_irq(pdev, 0);
                if (irq < 0) {
                        dev_err(dev, "%s: error getting IRQ resource - %d\n",
@@ -333,6 +398,16 @@ static int of_get_omap_rng_device_details(struct omap_rng_dev *priv,
                        return err;
                }
                omap_rng_write(priv, RNG_INTMASK_REG, RNG_SHUTDOWN_OFLO_MASK);
+
+               priv->clk = of_clk_get(pdev->dev.of_node, 0);
+               if (IS_ERR(priv->clk) && PTR_ERR(priv->clk) == -EPROBE_DEFER)
+                       return -EPROBE_DEFER;
+               if (!IS_ERR(priv->clk)) {
+                       err = clk_prepare_enable(priv->clk);
+                       if (err)
+                               dev_err(&pdev->dev, "unable to enable the clk, "
+                                                   "err = %d\n", err);
+               }
        }
        return 0;
 }
@@ -394,7 +469,7 @@ static int omap_rng_probe(struct platform_device *pdev)
        ret = (dev->of_node) ? of_get_omap_rng_device_details(priv, pdev) :
                                get_omap_rng_device_details(priv);
        if (ret)
-               goto err_ioremap;
+               goto err_register;
 
        ret = hwrng_register(&priv->rng);
        if (ret)
@@ -407,7 +482,11 @@ static int omap_rng_probe(struct platform_device *pdev)
 
 err_register:
        priv->base = NULL;
+       pm_runtime_put_sync(&pdev->dev);
        pm_runtime_disable(&pdev->dev);
+
+       if (!IS_ERR(priv->clk))
+               clk_disable_unprepare(priv->clk);
 err_ioremap:
        dev_err(dev, "initialization failed.\n");
        return ret;
@@ -424,6 +503,9 @@ static int omap_rng_remove(struct platform_device *pdev)
        pm_runtime_put_sync(&pdev->dev);
        pm_runtime_disable(&pdev->dev);
 
+       if (!IS_ERR(priv->clk))
+               clk_disable_unprepare(priv->clk);
+
        return 0;
 }