diff options
Diffstat (limited to 'arch/x86/platform/olpc/olpc.c')
| -rw-r--r-- | arch/x86/platform/olpc/olpc.c | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/arch/x86/platform/olpc/olpc.c b/arch/x86/platform/olpc/olpc.c new file mode 100644 index 00000000000..edaf3fe8dc5 --- /dev/null +++ b/arch/x86/platform/olpc/olpc.c @@ -0,0 +1,281 @@ +/* + * 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 <linux/platform_device.h> + +#include <asm/geode.h> +#include <asm/setup.h> +#include <asm/olpc.h> +#include <asm/olpc_ofw.h> + +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; + int restarts = 0; + + 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.. + */ + pr_devel("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; + } + pr_devel("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"); + if (restarts++ < 10) + goto restart; + goto err; + } + outbuf[i] = inb(0x68); + pr_devel("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); + +static bool __init check_ofw_architecture(void) +{ + size_t propsize; + char olpc_arch[5]; + const void *args[] = { NULL, "architecture", olpc_arch, (void *)5 }; + void *res[] = { &propsize }; + + if (olpc_ofw("getprop", args, res)) { + printk(KERN_ERR "ofw: getprop call failed!\n"); + return false; + } + return propsize == 5 && strncmp("OLPC", olpc_arch, 5) == 0; +} + +static u32 __init get_board_revision(void) +{ + size_t propsize; + __be32 rev; + const void *args[] = { NULL, "board-revision-int", &rev, (void *)4 }; + void *res[] = { &propsize }; + + if (olpc_ofw("getprop", args, res) || propsize != 4) { + printk(KERN_ERR "ofw: getprop call failed!\n"); + return cpu_to_be32(0); + } + return be32_to_cpu(rev); +} + +static bool __init platform_detect(void) +{ + if (!check_ofw_architecture()) + return false; + olpc_platform_info.flags |= OLPC_F_PRESENT; + olpc_platform_info.boardrev = get_board_revision(); + return true; +} + +static int __init add_xo1_platform_devices(void) +{ + struct platform_device *pdev; + + pdev = platform_device_register_simple("xo1-rfkill", -1, NULL, 0); + if (IS_ERR(pdev)) + return PTR_ERR(pdev); + + pdev = platform_device_register_simple("olpc-xo1", -1, NULL, 0); + if (IS_ERR(pdev)) + return PTR_ERR(pdev); + + return 0; +} + +static int __init olpc_init(void) +{ + int r = 0; + + if (!olpc_ofw_present() || !platform_detect()) + return 0; + + spin_lock_init(&ec_lock); + + /* 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); + +#ifdef CONFIG_PCI_OLPC + /* If the VSA exists let it emulate PCI, if not emulate in kernel. + * XO-1 only. */ + if (olpc_platform_info.boardrev < olpc_board_pre(0xd0) && + !cs5535_has_vsa2()) + x86_init.pci.arch_init = pci_olpc_init; +#endif + + 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); + + if (olpc_platform_info.boardrev < olpc_board_pre(0xd0)) { /* XO-1 */ + r = add_xo1_platform_devices(); + if (r) + return r; + } + + return 0; +} + +postcore_initcall(olpc_init); |