diff options
Diffstat (limited to 'arch/x86/platform/olpc/olpc.c')
| -rw-r--r-- | arch/x86/platform/olpc/olpc.c | 321 |
1 files changed, 321 insertions, 0 deletions
diff --git a/arch/x86/platform/olpc/olpc.c b/arch/x86/platform/olpc/olpc.c new file mode 100644 index 000000000..1d4a00e76 --- /dev/null +++ b/arch/x86/platform/olpc/olpc.c @@ -0,0 +1,321 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Support for the OLPC DCON and OLPC EC access + * + * Copyright © 2006 Advanced Micro Devices, Inc. + * Copyright © 2007-2008 Andres Salomon <dilinger@debian.org> + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/export.h> +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/string.h> +#include <linux/platform_device.h> +#include <linux/of.h> +#include <linux/syscore_ops.h> +#include <linux/mutex.h> +#include <linux/olpc-ec.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); + +/* 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. + */ +static int olpc_xo1_ec_cmd(u8 cmd, u8 *inbuf, size_t inlen, u8 *outbuf, + size_t outlen, void *arg) +{ + int ret = -EIO; + int i; + int restarts = 0; + + /* 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++) { + pr_devel("olpc-ec: sending cmd arg 0x%x\n", inbuf[i]); + outb(inbuf[i], 0x68); + if (wait_on_ibf(0x6c, 0)) { + printk(KERN_ERR "olpc-ec: timeout waiting for" + " EC accept data!\n"); + goto err; + } + } + } + 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: + return ret; +} + +static bool __init check_ofw_architecture(struct device_node *root) +{ + const char *olpc_arch; + int propsize; + + olpc_arch = of_get_property(root, "architecture", &propsize); + return propsize == 5 && strncmp("OLPC", olpc_arch, 5) == 0; +} + +static u32 __init get_board_revision(struct device_node *root) +{ + int propsize; + const __be32 *rev; + + rev = of_get_property(root, "board-revision-int", &propsize); + if (propsize != 4) + return 0; + + return be32_to_cpu(*rev); +} + +static bool __init platform_detect(void) +{ + struct device_node *root = of_find_node_by_path("/"); + bool success; + + if (!root) + return false; + + success = check_ofw_architecture(root); + if (success) { + olpc_platform_info.boardrev = get_board_revision(root); + olpc_platform_info.flags |= OLPC_F_PRESENT; + + pr_info("OLPC board revision %s%X\n", + ((olpc_platform_info.boardrev & 0xf) < 8) ? "pre" : "", + olpc_platform_info.boardrev >> 4); + } + + of_node_put(root); + return success; +} + +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); + + return PTR_ERR_OR_ZERO(pdev); +} + +static int olpc_xo1_ec_suspend(struct platform_device *pdev) +{ + /* + * Squelch SCIs while suspended. This is a fix for + * <http://dev.laptop.org/ticket/1835>. + */ + return olpc_ec_cmd(EC_SET_SCI_INHIBIT, NULL, 0, NULL, 0); +} + +static int olpc_xo1_ec_resume(struct platform_device *pdev) +{ + /* Tell the EC to stop inhibiting SCIs */ + olpc_ec_cmd(EC_SET_SCI_INHIBIT_RELEASE, NULL, 0, NULL, 0); + + /* + * Tell the wireless module to restart USB communication. + * Must be done twice. + */ + olpc_ec_cmd(EC_WAKE_UP_WLAN, NULL, 0, NULL, 0); + olpc_ec_cmd(EC_WAKE_UP_WLAN, NULL, 0, NULL, 0); + + return 0; +} + +static struct olpc_ec_driver ec_xo1_driver = { + .suspend = olpc_xo1_ec_suspend, + .resume = olpc_xo1_ec_resume, + .ec_cmd = olpc_xo1_ec_cmd, +#ifdef CONFIG_OLPC_XO1_SCI + /* + * XO-1 EC wakeups are available when olpc-xo1-sci driver is + * compiled in + */ + .wakeup_available = true, +#endif +}; + +static struct olpc_ec_driver ec_xo1_5_driver = { + .ec_cmd = olpc_xo1_ec_cmd, +#ifdef CONFIG_OLPC_XO15_SCI + /* + * XO-1.5 EC wakeups are available when olpc-xo15-sci driver is + * compiled in + */ + .wakeup_available = true, +#endif +}; + +static int __init olpc_init(void) +{ + int r = 0; + + if (!olpc_ofw_present() || !platform_detect()) + return 0; + + /* register the XO-1 and 1.5-specific EC handler */ + if (olpc_platform_info.boardrev < olpc_board_pre(0xd0)) /* XO-1 */ + olpc_ec_driver_register(&ec_xo1_driver, NULL); + else + olpc_ec_driver_register(&ec_xo1_5_driver, NULL); + platform_device_register_simple("olpc-ec", -1, NULL, 0); + + /* assume B1 and above models always have a DCON */ + if (olpc_board_at_least(olpc_board(0xb1))) + olpc_platform_info.flags |= OLPC_F_DCON; + +#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 + + 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); |