MIPS: PowerTV: Base files for Cisco PowerTV platform

Add the Cisco Powertv cable settop box to the MIPS tree. This platform is
based on a MIPS 24Kc processor with various devices integrated on the same
ASIC. There are multiple models of this box, with differing configuration
but the same kernel runs across the product line.

Signed-off-by: David VomLehn <dvomlehn@cisco.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/132/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 351 insertions, 0 deletions

diff --git a/arch/mips/powertv/powertv_setup.c b/arch/mips/powertv/powertv_setup.c
new file mode 100644
index 000000000000..bd8ebf128f29
--- /dev/null
+++ b/arch/mips/powertv/powertv_setup.c
@@ -0,0 +1,351 @@
+/*
+ * Carsten Langgaard, carstenl@mips.com
+ * Copyright (C) 2000 MIPS Technologies, Inc.  All rights reserved.
+ * Portions copyright (C) 2009 Cisco Systems, Inc.
+ *
+ *  This program is free software; you can distribute it and/or modify it
+ *  under the terms of the GNU General Public License (Version 2) as
+ *  published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope 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.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ */
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/ioport.h>
+#include <linux/pci.h>
+#include <linux/screen_info.h>
+#include <linux/notifier.h>
+#include <linux/etherdevice.h>
+#include <linux/if_ether.h>
+#include <linux/ctype.h>
+
+#include <linux/cpu.h>
+#include <asm/bootinfo.h>
+#include <asm/irq.h>
+#include <asm/mips-boards/generic.h>
+#include <asm/mips-boards/prom.h>
+#include <asm/dma.h>
+#include <linux/time.h>
+#include <asm/traps.h>
+#include <asm/asm-offsets.h>
+#include "reset.h"
+
+#define VAL(n)          STR(n)
+
+/*
+ * Macros for loading addresses and storing registers:
+ * PTR_LA       Load the address into a register
+ * LONG_S       Store the full width of the given register.
+ * LONG_L       Load the full width of the given register
+ * PTR_ADDIU    Add a constant value to a register used as a pointer
+ * REG_SIZE     Number of 8-bit bytes in a full width register
+ */
+#ifdef CONFIG_64BIT
+#warning TODO: 64-bit code needs to be verified
+#define PTR_LA          "dla    "
+#define LONG_S          "sd     "
+#define LONG_L          "ld     "
+#define PTR_ADDIU       "daddiu "
+#define REG_SIZE        "8"             /* In bytes */
+#endif
+
+#ifdef CONFIG_32BIT
+#define PTR_LA          "la     "
+#define LONG_S          "sw     "
+#define LONG_L          "lw     "
+#define PTR_ADDIU       "addiu  "
+#define REG_SIZE        "4"             /* In bytes */
+#endif
+
+static struct pt_regs die_regs;
+static bool have_die_regs;
+
+static void register_panic_notifier(void);
+static int panic_handler(struct notifier_block *notifier_block,
+        unsigned long event, void *cause_string);
+
+const char *get_system_type(void)
+{
+        return "PowerTV";
+}
+
+void __init plat_mem_setup(void)
+{
+        panic_on_oops = 1;
+        register_panic_notifier();
+
+#if 0
+        mips_pcibios_init();
+#endif
+        mips_reboot_setup();
+}
+
+/*
+ * Install a panic notifier for platform-specific diagnostics
+ */
+static void register_panic_notifier()
+{
+        static struct notifier_block panic_notifier = {
+                .notifier_call = panic_handler,
+                .next = NULL,
+                .priority       = INT_MAX
+        };
+        atomic_notifier_chain_register(&panic_notifier_list, &panic_notifier);
+}
+
+static int panic_handler(struct notifier_block *notifier_block,
+        unsigned long event, void *cause_string)
+{
+        struct pt_regs  my_regs;
+
+        /* Save all of the registers */
+        {
+                unsigned long   at, v0, v1; /* Must be on the stack */
+
+                /* Start by saving $at and v0 on the stack. We use $at
+                 * ourselves, but it looks like the compiler may use v0 or v1
+                 * to load the address of the pt_regs structure. We'll come
+                 * back later to store the registers in the pt_regs
+                 * structure. */
+                __asm__ __volatile__ (
+                        ".set   noat\n"
+                        LONG_S          "$at, %[at]\n"
+                        LONG_S          "$2, %[v0]\n"
+                        LONG_S          "$3, %[v1]\n"
+                :
+                        [at] "=m" (at),
+                        [v0] "=m" (v0),
+                        [v1] "=m" (v1)
+                :
+                :       "at"
+                );
+
+                __asm__ __volatile__ (
+                        ".set   noat\n"
+                        "move           $at, %[pt_regs]\n"
+
+                        /* Argument registers */
+                        LONG_S          "$4, " VAL(PT_R4) "($at)\n"
+                        LONG_S          "$5, " VAL(PT_R5) "($at)\n"
+                        LONG_S          "$6, " VAL(PT_R6) "($at)\n"
+                        LONG_S          "$7, " VAL(PT_R7) "($at)\n"
+
+                        /* Temporary regs */
+                        LONG_S          "$8, " VAL(PT_R8) "($at)\n"
+                        LONG_S          "$9, " VAL(PT_R9) "($at)\n"
+                        LONG_S          "$10, " VAL(PT_R10) "($at)\n"
+                        LONG_S          "$11, " VAL(PT_R11) "($at)\n"
+                        LONG_S          "$12, " VAL(PT_R12) "($at)\n"
+                        LONG_S          "$13, " VAL(PT_R13) "($at)\n"
+                        LONG_S          "$14, " VAL(PT_R14) "($at)\n"
+                        LONG_S          "$15, " VAL(PT_R15) "($at)\n"
+
+                        /* "Saved" registers */
+                        LONG_S          "$16, " VAL(PT_R16) "($at)\n"
+                        LONG_S          "$17, " VAL(PT_R17) "($at)\n"
+                        LONG_S          "$18, " VAL(PT_R18) "($at)\n"
+                        LONG_S          "$19, " VAL(PT_R19) "($at)\n"
+                        LONG_S          "$20, " VAL(PT_R20) "($at)\n"
+                        LONG_S          "$21, " VAL(PT_R21) "($at)\n"
+                        LONG_S          "$22, " VAL(PT_R22) "($at)\n"
+                        LONG_S          "$23, " VAL(PT_R23) "($at)\n"
+
+                        /* Add'l temp regs */
+                        LONG_S          "$24, " VAL(PT_R24) "($at)\n"
+                        LONG_S          "$25, " VAL(PT_R25) "($at)\n"
+
+                        /* Kernel temp regs */
+                        LONG_S          "$26, " VAL(PT_R26) "($at)\n"
+                        LONG_S          "$27, " VAL(PT_R27) "($at)\n"
+
+                        /* Global pointer, stack pointer, frame pointer and
+                         * return address */
+                        LONG_S          "$gp, " VAL(PT_R28) "($at)\n"
+                        LONG_S          "$sp, " VAL(PT_R29) "($at)\n"
+                        LONG_S          "$fp, " VAL(PT_R30) "($at)\n"
+                        LONG_S          "$ra, " VAL(PT_R31) "($at)\n"
+
+                        /* Now we can get the $at and v0 registers back and
+                         * store them */
+                        LONG_L          "$8, %[at]\n"
+                        LONG_S          "$8, " VAL(PT_R1) "($at)\n"
+                        LONG_L          "$8, %[v0]\n"
+                        LONG_S          "$8, " VAL(PT_R2) "($at)\n"
+                        LONG_L          "$8, %[v1]\n"
+                        LONG_S          "$8, " VAL(PT_R3) "($at)\n"
+                :
+                :
+                        [at] "m" (at),
+                        [v0] "m" (v0),
+                        [v1] "m" (v1),
+                        [pt_regs] "r" (&my_regs)
+                :       "at", "t0"
+                );
+
+                /* Set the current EPC value to be the current location in this
+                 * function */
+                __asm__ __volatile__ (
+                        ".set   noat\n"
+                "1:\n"
+                        PTR_LA          "$at, 1b\n"
+                        LONG_S          "$at, %[cp0_epc]\n"
+                :
+                        [cp0_epc] "=m" (my_regs.cp0_epc)
+                :
+                :       "at"
+                );
+
+                my_regs.cp0_cause = read_c0_cause();
+                my_regs.cp0_status = read_c0_status();
+        }
+
+#ifdef CONFIG_DIAGNOSTICS
+        failure_report((char *) cause_string,
+                have_die_regs ? &die_regs : &my_regs);
+        have_die_regs = false;
+#else
+        pr_crit("I'm feeling a bit sleepy. hmmmmm... perhaps a nap would... "
+                "zzzz... \n");
+#endif
+
+        return NOTIFY_DONE;
+}
+
+/**
+ * Platform-specific handling of oops
+ * @str:        Pointer to the oops string
+ * @regs:       Pointer to the oops registers
+ * All we do here is to save the registers for subsequent printing through
+ * the panic notifier.
+ */
+void platform_die(const char *str, const struct pt_regs *regs)
+{
+        /* If we already have saved registers, don't overwrite them as they
+         * they apply to the initial fault */
+
+        if (!have_die_regs) {
+                have_die_regs = true;
+                die_regs = *regs;
+        }
+}
+
+/* Information about the RF MAC address, if one was supplied on the
+ * command line. */
+static bool have_rfmac;
+static u8 rfmac[ETH_ALEN];
+
+static int rfmac_param(char *p)
+{
+        u8      *q;
+        bool    is_high_nibble;
+        int     c;
+
+        /* Skip a leading "0x", if present */
+        if (*p == '0' && *(p+1) == 'x')
+                p += 2;
+
+        q = rfmac;
+        is_high_nibble = true;
+
+        for (c = (unsigned char) *p++;
+                isxdigit(c) && q - rfmac < ETH_ALEN;
+                c = (unsigned char) *p++) {
+                int     nibble;
+
+                nibble = (isdigit(c) ? (c - '0') :
+                        (isupper(c) ? c - 'A' + 10 : c - 'a' + 10));
+
+                if (is_high_nibble)
+                        *q = nibble << 4;
+                else
+                        *q++ |= nibble;
+
+                is_high_nibble = !is_high_nibble;
+        }
+
+        /* If we parsed all the way to the end of the parameter value and
+         * parsed all ETH_ALEN bytes, we have a usable RF MAC address */
+        have_rfmac = (c == '\0' && q - rfmac == ETH_ALEN);
+
+        return 0;
+}
+
+early_param("rfmac", rfmac_param);
+
+/*
+ * Generate an Ethernet MAC address that has a good chance of being unique.
+ * @addr:       Pointer to six-byte array containing the Ethernet address
+ * Generates an Ethernet MAC address that is highly likely to be unique for
+ * this particular system on a network with other systems of the same type.
+ *
+ * The problem we are solving is that, when random_ether_addr() is used to
+ * generate MAC addresses at startup, there isn't much entropy for the random
+ * number generator to use and the addresses it produces are fairly likely to
+ * be the same as those of other identical systems on the same local network.
+ * This is true even for relatively small numbers of systems (for the reason
+ * why, see the Wikipedia entry for "Birthday problem" at:
+ *      http://en.wikipedia.org/wiki/Birthday_problem
+ *
+ * The good news is that we already have a MAC address known to be unique, the
+ * RF MAC address. The bad news is that this address is already in use on the
+ * RF interface. Worse, the obvious trick, taking the RF MAC address and
+ * turning on the locally managed bit, has already been used for other devices.
+ * Still, this does give us something to work with.
+ *
+ * The approach we take is:
+ * 1.   If we can't get the RF MAC Address, just call random_ether_addr.
+ * 2.   Use the 24-bit NIC-specific bits of the RF MAC address as the last 24
+ *      bits of the new address. This is very likely to be unique, except for
+ *      the current box.
+ * 3.   To avoid using addresses already on the current box, we set the top
+ *      six bits of the address with a value different from any currently
+ *      registered Scientific Atlanta organizationally unique identifyer
+ *      (OUI). This avoids duplication with any addresses on the system that
+ *      were generated from valid Scientific Atlanta-registered address by
+ *      simply flipping the locally managed bit.
+ * 4.   We aren't generating a multicast address, so we leave the multicast
+ *      bit off. Since we aren't using a registered address, we have to set
+ *      the locally managed bit.
+ * 5.   We then randomly generate the remaining 16-bits. This does two
+ *      things:
+ *      a.      It allows us to call this function for more than one device
+ *              in this system
+ *      b.      It ensures that things will probably still work even if
+ *              some device on the device network has a locally managed
+ *              address that matches the top six bits from step 2.
+ */
+void platform_random_ether_addr(u8 addr[ETH_ALEN])
+{
+        const int num_random_bytes = 2;
+        const unsigned char non_sciatl_oui_bits = 0xc0u;
+        const unsigned char mac_addr_locally_managed = (1 << 1);
+
+        if (!have_rfmac) {
+                pr_warning("rfmac not available on command line; "
+                        "generating random MAC address\n");
+                random_ether_addr(addr);
+        }
+
+        else {
+                int     i;
+
+                /* Set the first byte to something that won't match a Scientific
+                 * Atlanta OUI, is locally managed, and isn't a multicast
+                 * address */
+                addr[0] = non_sciatl_oui_bits | mac_addr_locally_managed;
+
+                /* Get some bytes of random address information */
+                get_random_bytes(&addr[1], num_random_bytes);
+
+                /* Copy over the NIC-specific bits of the RF MAC address */
+                for (i = 1 + num_random_bytes; i < ETH_ALEN; i++)
+                        addr[i] = rfmac[i];
+        }
+}