1 files changed, 260 insertions, 0 deletions

diff --git a/arch/x86/kernel/olpc.c b/arch/x86/kernel/olpc.c
new file mode 100644
index 000000000000..3e6672274807
--- /dev/null
+++ b/arch/x86/kernel/olpc.c
@@ -0,0 +1,260 @@
+/*
+ * Support for the OLPC DCON and OLPC EC access
+ *
+ * Copyright © 2006  Advanced Micro Devices, Inc.
+ * Copyright © 2007-2008  Andres Salomon <dilinger@debian.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <linux/string.h>
+#include <asm/geode.h>
+#include <asm/olpc.h>
+
+#ifdef CONFIG_OPEN_FIRMWARE
+#include <asm/ofw.h>
+#endif
+
+struct olpc_platform_t olpc_platform_info;
+EXPORT_SYMBOL_GPL(olpc_platform_info);
+
+static DEFINE_SPINLOCK(ec_lock);
+
+/* what the timeout *should* be (in ms) */
+#define EC_BASE_TIMEOUT 20
+
+/* the timeout that bugs in the EC might force us to actually use */
+static int ec_timeout = EC_BASE_TIMEOUT;
+
+static int __init olpc_ec_timeout_set(char *str)
+{
+        if (get_option(&str, &ec_timeout) != 1) {
+                ec_timeout = EC_BASE_TIMEOUT;
+                printk(KERN_ERR "olpc-ec:  invalid argument to "
+                                "'olpc_ec_timeout=', ignoring!\n");
+        }
+        printk(KERN_DEBUG "olpc-ec:  using %d ms delay for EC commands.\n",
+                        ec_timeout);
+        return 1;
+}
+__setup("olpc_ec_timeout=", olpc_ec_timeout_set);
+
+/*
+ * These {i,o}bf_status functions return whether the buffers are full or not.
+ */
+
+static inline unsigned int ibf_status(unsigned int port)
+{
+        return !!(inb(port) & 0x02);
+}
+
+static inline unsigned int obf_status(unsigned int port)
+{
+        return inb(port) & 0x01;
+}
+
+#define wait_on_ibf(p, d) __wait_on_ibf(__LINE__, (p), (d))
+static int __wait_on_ibf(unsigned int line, unsigned int port, int desired)
+{
+        unsigned int timeo;
+        int state = ibf_status(port);
+
+        for (timeo = ec_timeout; state != desired && timeo; timeo--) {
+                mdelay(1);
+                state = ibf_status(port);
+        }
+
+        if ((state == desired) && (ec_timeout > EC_BASE_TIMEOUT) &&
+                        timeo < (ec_timeout - EC_BASE_TIMEOUT)) {
+                printk(KERN_WARNING "olpc-ec:  %d: waited %u ms for IBF!\n",
+                                line, ec_timeout - timeo);
+        }
+
+        return !(state == desired);
+}
+
+#define wait_on_obf(p, d) __wait_on_obf(__LINE__, (p), (d))
+static int __wait_on_obf(unsigned int line, unsigned int port, int desired)
+{
+        unsigned int timeo;
+        int state = obf_status(port);
+
+        for (timeo = ec_timeout; state != desired && timeo; timeo--) {
+                mdelay(1);
+                state = obf_status(port);
+        }
+
+        if ((state == desired) && (ec_timeout > EC_BASE_TIMEOUT) &&
+                        timeo < (ec_timeout - EC_BASE_TIMEOUT)) {
+                printk(KERN_WARNING "olpc-ec:  %d: waited %u ms for OBF!\n",
+                                line, ec_timeout - timeo);
+        }
+
+        return !(state == desired);
+}
+
+/*
+ * This allows the kernel to run Embedded Controller commands.  The EC is
+ * documented at <http://wiki.laptop.org/go/Embedded_controller>, and the
+ * available EC commands are here:
+ * <http://wiki.laptop.org/go/Ec_specification>.  Unfortunately, while
+ * OpenFirmware's source is available, the EC's is not.
+ */
+int olpc_ec_cmd(unsigned char cmd, unsigned char *inbuf, size_t inlen,
+                unsigned char *outbuf,  size_t outlen)
+{
+        unsigned long flags;
+        int ret = -EIO;
+        int i;
+
+        spin_lock_irqsave(&ec_lock, flags);
+
+        /* Clear OBF */
+        for (i = 0; i < 10 && (obf_status(0x6c) == 1); i++)
+                inb(0x68);
+        if (i == 10) {
+                printk(KERN_ERR "olpc-ec:  timeout while attempting to "
+                                "clear OBF flag!\n");
+                goto err;
+        }
+
+        if (wait_on_ibf(0x6c, 0)) {
+                printk(KERN_ERR "olpc-ec:  timeout waiting for EC to "
+                                "quiesce!\n");
+                goto err;
+        }
+
+restart:
+        /*
+         * Note that if we time out during any IBF checks, that's a failure;
+         * we have to return.  There's no way for the kernel to clear that.
+         *
+         * If we time out during an OBF check, we can restart the command;
+         * reissuing it will clear the OBF flag, and we should be alright.
+         * The OBF flag will sometimes misbehave due to what we believe
+         * is a hardware quirk..
+         */
+        printk(KERN_DEBUG "olpc-ec:  running cmd 0x%x\n", cmd);
+        outb(cmd, 0x6c);
+
+        if (wait_on_ibf(0x6c, 0)) {
+                printk(KERN_ERR "olpc-ec:  timeout waiting for EC to read "
+                                "command!\n");
+                goto err;
+        }
+
+        if (inbuf && inlen) {
+                /* write data to EC */
+                for (i = 0; i < inlen; i++) {
+                        if (wait_on_ibf(0x6c, 0)) {
+                                printk(KERN_ERR "olpc-ec:  timeout waiting for"
+                                                " EC accept data!\n");
+                                goto err;
+                        }
+                        printk(KERN_DEBUG "olpc-ec:  sending cmd arg 0x%x\n",
+                                        inbuf[i]);
+                        outb(inbuf[i], 0x68);
+                }
+        }
+        if (outbuf && outlen) {
+                /* read data from EC */
+                for (i = 0; i < outlen; i++) {
+                        if (wait_on_obf(0x6c, 1)) {
+                                printk(KERN_ERR "olpc-ec:  timeout waiting for"
+                                                " EC to provide data!\n");
+                                goto restart;
+                        }
+                        outbuf[i] = inb(0x68);
+                        printk(KERN_DEBUG "olpc-ec:  received 0x%x\n",
+                                        outbuf[i]);
+                }
+        }
+
+        ret = 0;
+err:
+        spin_unlock_irqrestore(&ec_lock, flags);
+        return ret;
+}
+EXPORT_SYMBOL_GPL(olpc_ec_cmd);
+
+#ifdef CONFIG_OPEN_FIRMWARE
+static void __init platform_detect(void)
+{
+        size_t propsize;
+        u32 rev;
+
+        if (ofw("getprop", 4, 1, NULL, "board-revision-int", &rev, 4,
+                        &propsize) || propsize != 4) {
+                printk(KERN_ERR "ofw: getprop call failed!\n");
+                rev = 0;
+        }
+        olpc_platform_info.boardrev = be32_to_cpu(rev);
+}
+#else
+static void __init platform_detect(void)
+{
+        /* stopgap until OFW support is added to the kernel */
+        olpc_platform_info.boardrev = be32_to_cpu(0xc2);
+}
+#endif
+
+static int __init olpc_init(void)
+{
+        unsigned char *romsig;
+
+        /* The ioremap check is dangerous; limit what we run it on */
+        if (!is_geode() || geode_has_vsa2())
+                return 0;
+
+        spin_lock_init(&ec_lock);
+
+        romsig = ioremap(0xffffffc0, 16);
+        if (!romsig)
+                return 0;
+
+        if (strncmp(romsig, "CL1   Q", 7))
+                goto unmap;
+        if (strncmp(romsig+6, romsig+13, 3)) {
+                printk(KERN_INFO "OLPC BIOS signature looks invalid.  "
+                                "Assuming not OLPC\n");
+                goto unmap;
+        }
+
+        printk(KERN_INFO "OLPC board with OpenFirmware %.16s\n", romsig);
+        olpc_platform_info.flags |= OLPC_F_PRESENT;
+
+        /* get the platform revision */
+        platform_detect();
+
+        /* assume B1 and above models always have a DCON */
+        if (olpc_board_at_least(olpc_board(0xb1)))
+                olpc_platform_info.flags |= OLPC_F_DCON;
+
+        /* get the EC revision */
+        olpc_ec_cmd(EC_FIRMWARE_REV, NULL, 0,
+                        (unsigned char *) &olpc_platform_info.ecver, 1);
+
+        /* check to see if the VSA exists */
+        if (geode_has_vsa2())
+                olpc_platform_info.flags |= OLPC_F_VSA;
+
+        printk(KERN_INFO "OLPC board revision %s%X (EC=%x)\n",
+                        ((olpc_platform_info.boardrev & 0xf) < 8) ? "pre" : "",
+                        olpc_platform_info.boardrev >> 4,
+                        olpc_platform_info.ecver);
+
+unmap:
+        iounmap(romsig);
+        return 0;
+}
+
+postcore_initcall(olpc_init);