From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- drivers/platform/olpc/olpc-ec.c | 495 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 495 insertions(+) create mode 100644 drivers/platform/olpc/olpc-ec.c (limited to 'drivers/platform/olpc/olpc-ec.c') diff --git a/drivers/platform/olpc/olpc-ec.c b/drivers/platform/olpc/olpc-ec.c new file mode 100644 index 000000000..921520475 --- /dev/null +++ b/drivers/platform/olpc/olpc-ec.c @@ -0,0 +1,495 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Generic driver for the OLPC Embedded Controller. + * + * Author: Andres Salomon + * + * Copyright (C) 2011-2012 One Laptop per Child Foundation. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct ec_cmd_desc { + u8 cmd; + u8 *inbuf, *outbuf; + size_t inlen, outlen; + + int err; + struct completion finished; + struct list_head node; + + void *priv; +}; + +struct olpc_ec_priv { + struct olpc_ec_driver *drv; + u8 version; + struct work_struct worker; + struct mutex cmd_lock; + + /* DCON regulator */ + bool dcon_enabled; + + /* Pending EC commands */ + struct list_head cmd_q; + spinlock_t cmd_q_lock; + + struct dentry *dbgfs_dir; + + /* + * EC event mask to be applied during suspend (defining wakeup + * sources). + */ + u16 ec_wakeup_mask; + + /* + * Running an EC command while suspending means we don't always finish + * the command before the machine suspends. This means that the EC + * is expecting the command protocol to finish, but we after a period + * of time (while the OS is asleep) the EC times out and restarts its + * idle loop. Meanwhile, the OS wakes up, thinks it's still in the + * middle of the command protocol, starts throwing random things at + * the EC... and everyone's uphappy. + */ + bool suspended; +}; + +static struct olpc_ec_driver *ec_driver; +static struct olpc_ec_priv *ec_priv; +static void *ec_cb_arg; + +void olpc_ec_driver_register(struct olpc_ec_driver *drv, void *arg) +{ + ec_driver = drv; + ec_cb_arg = arg; +} +EXPORT_SYMBOL_GPL(olpc_ec_driver_register); + +static void olpc_ec_worker(struct work_struct *w) +{ + struct olpc_ec_priv *ec = container_of(w, struct olpc_ec_priv, worker); + struct ec_cmd_desc *desc = NULL; + unsigned long flags; + + /* Grab the first pending command from the queue */ + spin_lock_irqsave(&ec->cmd_q_lock, flags); + if (!list_empty(&ec->cmd_q)) { + desc = list_first_entry(&ec->cmd_q, struct ec_cmd_desc, node); + list_del(&desc->node); + } + spin_unlock_irqrestore(&ec->cmd_q_lock, flags); + + /* Do we actually have anything to do? */ + if (!desc) + return; + + /* Protect the EC hw with a mutex; only run one cmd at a time */ + mutex_lock(&ec->cmd_lock); + desc->err = ec_driver->ec_cmd(desc->cmd, desc->inbuf, desc->inlen, + desc->outbuf, desc->outlen, ec_cb_arg); + mutex_unlock(&ec->cmd_lock); + + /* Finished, wake up olpc_ec_cmd() */ + complete(&desc->finished); + + /* Run the worker thread again in case there are more cmds pending */ + schedule_work(&ec->worker); +} + +/* + * Throw a cmd descripter onto the list. We now have SMP OLPC machines, so + * locking is pretty critical. + */ +static void queue_ec_descriptor(struct ec_cmd_desc *desc, + struct olpc_ec_priv *ec) +{ + unsigned long flags; + + INIT_LIST_HEAD(&desc->node); + + spin_lock_irqsave(&ec->cmd_q_lock, flags); + list_add_tail(&desc->node, &ec->cmd_q); + spin_unlock_irqrestore(&ec->cmd_q_lock, flags); + + schedule_work(&ec->worker); +} + +int olpc_ec_cmd(u8 cmd, u8 *inbuf, size_t inlen, u8 *outbuf, size_t outlen) +{ + struct olpc_ec_priv *ec = ec_priv; + struct ec_cmd_desc desc; + + /* Driver not yet registered. */ + if (!ec_driver) + return -EPROBE_DEFER; + + if (WARN_ON(!ec_driver->ec_cmd)) + return -ENODEV; + + if (!ec) + return -ENOMEM; + + /* Suspending in the middle of a command hoses things really badly */ + if (WARN_ON(ec->suspended)) + return -EBUSY; + + might_sleep(); + + desc.cmd = cmd; + desc.inbuf = inbuf; + desc.outbuf = outbuf; + desc.inlen = inlen; + desc.outlen = outlen; + desc.err = 0; + init_completion(&desc.finished); + + queue_ec_descriptor(&desc, ec); + + /* Timeouts must be handled in the platform-specific EC hook */ + wait_for_completion(&desc.finished); + + /* The worker thread dequeues the cmd; no need to do anything here */ + return desc.err; +} +EXPORT_SYMBOL_GPL(olpc_ec_cmd); + +void olpc_ec_wakeup_set(u16 value) +{ + struct olpc_ec_priv *ec = ec_priv; + + if (WARN_ON(!ec)) + return; + + ec->ec_wakeup_mask |= value; +} +EXPORT_SYMBOL_GPL(olpc_ec_wakeup_set); + +void olpc_ec_wakeup_clear(u16 value) +{ + struct olpc_ec_priv *ec = ec_priv; + + if (WARN_ON(!ec)) + return; + + ec->ec_wakeup_mask &= ~value; +} +EXPORT_SYMBOL_GPL(olpc_ec_wakeup_clear); + +int olpc_ec_mask_write(u16 bits) +{ + struct olpc_ec_priv *ec = ec_priv; + + if (WARN_ON(!ec)) + return -ENODEV; + + /* EC version 0x5f adds support for wide SCI mask */ + if (ec->version >= 0x5f) { + __be16 ec_word = cpu_to_be16(bits); + + return olpc_ec_cmd(EC_WRITE_EXT_SCI_MASK, (void *)&ec_word, 2, NULL, 0); + } else { + u8 ec_byte = bits & 0xff; + + return olpc_ec_cmd(EC_WRITE_SCI_MASK, &ec_byte, 1, NULL, 0); + } +} +EXPORT_SYMBOL_GPL(olpc_ec_mask_write); + +/* + * Returns true if the compile and runtime configurations allow for EC events + * to wake the system. + */ +bool olpc_ec_wakeup_available(void) +{ + if (WARN_ON(!ec_driver)) + return false; + + return ec_driver->wakeup_available; +} +EXPORT_SYMBOL_GPL(olpc_ec_wakeup_available); + +int olpc_ec_sci_query(u16 *sci_value) +{ + struct olpc_ec_priv *ec = ec_priv; + int ret; + + if (WARN_ON(!ec)) + return -ENODEV; + + /* EC version 0x5f adds support for wide SCI mask */ + if (ec->version >= 0x5f) { + __be16 ec_word; + + ret = olpc_ec_cmd(EC_EXT_SCI_QUERY, NULL, 0, (void *)&ec_word, 2); + if (ret == 0) + *sci_value = be16_to_cpu(ec_word); + } else { + u8 ec_byte; + + ret = olpc_ec_cmd(EC_SCI_QUERY, NULL, 0, &ec_byte, 1); + if (ret == 0) + *sci_value = ec_byte; + } + + return ret; +} +EXPORT_SYMBOL_GPL(olpc_ec_sci_query); + +#ifdef CONFIG_DEBUG_FS + +/* + * debugfs support for "generic commands", to allow sending + * arbitrary EC commands from userspace. + */ + +#define EC_MAX_CMD_ARGS (5 + 1) /* cmd byte + 5 args */ +#define EC_MAX_CMD_REPLY (8) + +static DEFINE_MUTEX(ec_dbgfs_lock); +static unsigned char ec_dbgfs_resp[EC_MAX_CMD_REPLY]; +static unsigned int ec_dbgfs_resp_bytes; + +static ssize_t ec_dbgfs_cmd_write(struct file *file, const char __user *buf, + size_t size, loff_t *ppos) +{ + int i, m; + unsigned char ec_cmd[EC_MAX_CMD_ARGS]; + unsigned int ec_cmd_int[EC_MAX_CMD_ARGS]; + char cmdbuf[64] = ""; + int ec_cmd_bytes; + + mutex_lock(&ec_dbgfs_lock); + + size = simple_write_to_buffer(cmdbuf, sizeof(cmdbuf), ppos, buf, size); + + m = sscanf(cmdbuf, "%x:%u %x %x %x %x %x", &ec_cmd_int[0], + &ec_dbgfs_resp_bytes, &ec_cmd_int[1], &ec_cmd_int[2], + &ec_cmd_int[3], &ec_cmd_int[4], &ec_cmd_int[5]); + if (m < 2 || ec_dbgfs_resp_bytes > EC_MAX_CMD_REPLY) { + /* reset to prevent overflow on read */ + ec_dbgfs_resp_bytes = 0; + + pr_debug("olpc-ec: bad ec cmd: cmd:response-count [arg1 [arg2 ...]]\n"); + size = -EINVAL; + goto out; + } + + /* convert scanf'd ints to char */ + ec_cmd_bytes = m - 2; + for (i = 0; i <= ec_cmd_bytes; i++) + ec_cmd[i] = ec_cmd_int[i]; + + pr_debug("olpc-ec: debugfs cmd 0x%02x with %d args %5ph, want %d returns\n", + ec_cmd[0], ec_cmd_bytes, ec_cmd + 1, + ec_dbgfs_resp_bytes); + + olpc_ec_cmd(ec_cmd[0], (ec_cmd_bytes == 0) ? NULL : &ec_cmd[1], + ec_cmd_bytes, ec_dbgfs_resp, ec_dbgfs_resp_bytes); + + pr_debug("olpc-ec: response %8ph (%d bytes expected)\n", + ec_dbgfs_resp, ec_dbgfs_resp_bytes); + +out: + mutex_unlock(&ec_dbgfs_lock); + return size; +} + +static ssize_t ec_dbgfs_cmd_read(struct file *file, char __user *buf, + size_t size, loff_t *ppos) +{ + unsigned int i, r; + char *rp; + char respbuf[64]; + + mutex_lock(&ec_dbgfs_lock); + rp = respbuf; + rp += sprintf(rp, "%02x", ec_dbgfs_resp[0]); + for (i = 1; i < ec_dbgfs_resp_bytes; i++) + rp += sprintf(rp, ", %02x", ec_dbgfs_resp[i]); + mutex_unlock(&ec_dbgfs_lock); + rp += sprintf(rp, "\n"); + + r = rp - respbuf; + return simple_read_from_buffer(buf, size, ppos, respbuf, r); +} + +static const struct file_operations ec_dbgfs_ops = { + .write = ec_dbgfs_cmd_write, + .read = ec_dbgfs_cmd_read, +}; + +static struct dentry *olpc_ec_setup_debugfs(void) +{ + struct dentry *dbgfs_dir; + + dbgfs_dir = debugfs_create_dir("olpc-ec", NULL); + if (IS_ERR_OR_NULL(dbgfs_dir)) + return NULL; + + debugfs_create_file("cmd", 0600, dbgfs_dir, NULL, &ec_dbgfs_ops); + + return dbgfs_dir; +} + +#else + +static struct dentry *olpc_ec_setup_debugfs(void) +{ + return NULL; +} + +#endif /* CONFIG_DEBUG_FS */ + +static int olpc_ec_set_dcon_power(struct olpc_ec_priv *ec, bool state) +{ + unsigned char ec_byte = state; + int ret; + + if (ec->dcon_enabled == state) + return 0; + + ret = olpc_ec_cmd(EC_DCON_POWER_MODE, &ec_byte, 1, NULL, 0); + if (ret) + return ret; + + ec->dcon_enabled = state; + return 0; +} + +static int dcon_regulator_enable(struct regulator_dev *rdev) +{ + struct olpc_ec_priv *ec = rdev_get_drvdata(rdev); + + return olpc_ec_set_dcon_power(ec, true); +} + +static int dcon_regulator_disable(struct regulator_dev *rdev) +{ + struct olpc_ec_priv *ec = rdev_get_drvdata(rdev); + + return olpc_ec_set_dcon_power(ec, false); +} + +static int dcon_regulator_is_enabled(struct regulator_dev *rdev) +{ + struct olpc_ec_priv *ec = rdev_get_drvdata(rdev); + + return ec->dcon_enabled ? 1 : 0; +} + +static const struct regulator_ops dcon_regulator_ops = { + .enable = dcon_regulator_enable, + .disable = dcon_regulator_disable, + .is_enabled = dcon_regulator_is_enabled, +}; + +static const struct regulator_desc dcon_desc = { + .name = "dcon", + .id = 0, + .ops = &dcon_regulator_ops, + .type = REGULATOR_VOLTAGE, + .owner = THIS_MODULE, + .enable_time = 25000, +}; + +static int olpc_ec_probe(struct platform_device *pdev) +{ + struct olpc_ec_priv *ec; + struct regulator_config config = { }; + struct regulator_dev *regulator; + int err; + + if (!ec_driver) + return -ENODEV; + + ec = kzalloc(sizeof(*ec), GFP_KERNEL); + if (!ec) + return -ENOMEM; + + ec->drv = ec_driver; + INIT_WORK(&ec->worker, olpc_ec_worker); + mutex_init(&ec->cmd_lock); + + INIT_LIST_HEAD(&ec->cmd_q); + spin_lock_init(&ec->cmd_q_lock); + + ec_priv = ec; + platform_set_drvdata(pdev, ec); + + /* get the EC revision */ + err = olpc_ec_cmd(EC_FIRMWARE_REV, NULL, 0, &ec->version, 1); + if (err) + goto error; + + config.dev = pdev->dev.parent; + config.driver_data = ec; + ec->dcon_enabled = true; + regulator = devm_regulator_register(&pdev->dev, &dcon_desc, &config); + if (IS_ERR(regulator)) { + dev_err(&pdev->dev, "failed to register DCON regulator\n"); + err = PTR_ERR(regulator); + goto error; + } + + ec->dbgfs_dir = olpc_ec_setup_debugfs(); + + return 0; + +error: + ec_priv = NULL; + kfree(ec); + return err; +} + +static int olpc_ec_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct olpc_ec_priv *ec = platform_get_drvdata(pdev); + int err = 0; + + olpc_ec_mask_write(ec->ec_wakeup_mask); + + if (ec_driver->suspend) + err = ec_driver->suspend(pdev); + if (!err) + ec->suspended = true; + + return err; +} + +static int olpc_ec_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct olpc_ec_priv *ec = platform_get_drvdata(pdev); + + ec->suspended = false; + return ec_driver->resume ? ec_driver->resume(pdev) : 0; +} + +static const struct dev_pm_ops olpc_ec_pm_ops = { + .suspend_late = olpc_ec_suspend, + .resume_early = olpc_ec_resume, +}; + +static struct platform_driver olpc_ec_plat_driver = { + .probe = olpc_ec_probe, + .driver = { + .name = "olpc-ec", + .pm = &olpc_ec_pm_ops, + }, +}; + +static int __init olpc_ec_init_module(void) +{ + return platform_driver_register(&olpc_ec_plat_driver); +} +arch_initcall(olpc_ec_init_module); -- cgit v1.2.3