diff options
Diffstat (limited to 'drivers/platform')
-rw-r--r-- | drivers/platform/olpc/olpc-ec.c | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/drivers/platform/olpc/olpc-ec.c b/drivers/platform/olpc/olpc-ec.c index a3d32c2..1a15a79 100644 --- a/drivers/platform/olpc/olpc-ec.c +++ b/drivers/platform/olpc/olpc-ec.c @@ -6,6 +6,7 @@ * Licensed under the GPL v2 or later. */ #include <linux/completion.h> +#include <linux/debugfs.h> #include <linux/spinlock.h> #include <linux/mutex.h> #include <linux/platform_device.h> @@ -31,6 +32,8 @@ struct ec_cmd_desc { struct olpc_ec_priv { struct olpc_ec_driver *drv; + struct dentry *dbgfs_dir; + /* * Running an EC command while suspending means we don't always finish * the command before the machine suspends. This means that the EC @@ -144,6 +147,114 @@ int olpc_ec_cmd(u8 cmd, u8 *inbuf, size_t inlen, u8 *outbuf, size_t outlen) } EXPORT_SYMBOL_GPL(olpc_ec_cmd); +#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 %02x %02x %02x %02x %02x, want %d returns\n", + ec_cmd[0], ec_cmd_bytes, ec_cmd[1], ec_cmd[2], + ec_cmd[3], ec_cmd[4], ec_cmd[5], 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 %02x %02x %02x %02x %02x %02x %02x %02x (%d bytes expected)\n", + ec_dbgfs_resp[0], ec_dbgfs_resp[1], ec_dbgfs_resp[2], + ec_dbgfs_resp[3], ec_dbgfs_resp[4], ec_dbgfs_resp[5], + ec_dbgfs_resp[6], ec_dbgfs_resp[7], + 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_probe(struct platform_device *pdev) { struct olpc_ec_priv *ec; @@ -160,6 +271,12 @@ static int olpc_ec_probe(struct platform_device *pdev) platform_set_drvdata(pdev, ec); err = ec_driver->probe ? ec_driver->probe(pdev) : 0; + if (err) { + ec_priv = NULL; + kfree(ec); + } else { + ec->dbgfs_dir = olpc_ec_setup_debugfs(); + } return err; } |