diff options
Diffstat (limited to 'drivers/misc')
| -rw-r--r-- | drivers/misc/Kconfig | 39 | ||||
| -rw-r--r-- | drivers/misc/Makefile | 2 | ||||
| -rw-r--r-- | drivers/misc/eeprom/at24.c | 60 | ||||
| -rw-r--r-- | drivers/misc/eeprom/at25.c | 1 | ||||
| -rw-r--r-- | drivers/misc/hwlat_detector.c | 1208 | ||||
| -rw-r--r-- | drivers/misc/kgdbts.c | 6 | ||||
| -rw-r--r-- | drivers/misc/sgi-gru/grutables.h | 15 | ||||
| -rw-r--r-- | drivers/misc/tsl2550.c | 473 |
8 files changed, 1782 insertions, 22 deletions
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig index d16af6a423fb..625e3a62c696 100644 --- a/drivers/misc/Kconfig +++ b/drivers/misc/Kconfig @@ -90,6 +90,35 @@ config IBM_ASM information on the specific driver level and support statement for your IBM server. +config HWLAT_DETECTOR + tristate "Testing module to detect hardware-induced latencies" + depends on DEBUG_FS + depends on RING_BUFFER + default m + ---help--- + A simple hardware latency detector. Use this module to detect + large latencies introduced by the behavior of the underlying + system firmware external to Linux. We do this using periodic + use of stop_machine to grab all available CPUs and measure + for unexplainable gaps in the CPU timestamp counter(s). By + default, the module is not enabled until the "enable" file + within the "hwlat_detector" debugfs directory is toggled. + + This module is often used to detect SMI (System Management + Interrupts) on x86 systems, though is not x86 specific. To + this end, we default to using a sample window of 1 second, + during which we will sample for 0.5 seconds. If an SMI or + similar event occurs during that time, it is recorded + into an 8K samples global ring buffer until retreived. + + WARNING: This software should never be enabled (it can be built + but should not be turned on after it is loaded) in a production + environment where high latencies are a concern since the + sampling mechanism actually introduces latencies for + regular tasks while the CPU(s) are being held. + + If unsure, say N + config PHANTOM tristate "Sensable PHANToM (PCI)" depends on PCI @@ -268,6 +297,16 @@ config ISL29003 This driver can also be built as a module. If so, the module will be called isl29003. +config SENSORS_TSL2550 + tristate "Taos TSL2550 ambient light sensor" + depends on I2C && SYSFS + help + If you say yes here you get support for the Taos TSL2550 + ambient light sensor. + + This driver can also be built as a module. If so, the module + will be called tsl2550. + config EP93XX_PWM tristate "EP93xx PWM support" depends on ARCH_EP93XX diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile index 049ff2482f30..c221917a239c 100644 --- a/drivers/misc/Makefile +++ b/drivers/misc/Makefile @@ -21,10 +21,12 @@ obj-$(CONFIG_SGI_GRU) += sgi-gru/ obj-$(CONFIG_CS5535_MFGPT) += cs5535-mfgpt.o obj-$(CONFIG_HP_ILO) += hpilo.o obj-$(CONFIG_ISL29003) += isl29003.o +obj-$(CONFIG_SENSORS_TSL2550) += tsl2550.o obj-$(CONFIG_EP93XX_PWM) += ep93xx_pwm.o obj-$(CONFIG_DS1682) += ds1682.o obj-$(CONFIG_TI_DAC7512) += ti_dac7512.o obj-$(CONFIG_C2PORT) += c2port/ obj-$(CONFIG_IWMC3200TOP) += iwmc3200top/ +obj-$(CONFIG_HWLAT_DETECTOR) += hwlat_detector.o obj-y += eeprom/ obj-y += cb710/ diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index 2cb2736d65aa..0c11e411d8ec 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -54,7 +54,7 @@ struct at24_data { struct at24_platform_data chip; struct memory_accessor macc; - bool use_smbus; + int use_smbus; /* * Lock protects against activities from other Linux tasks, @@ -184,11 +184,19 @@ static ssize_t at24_eeprom_read(struct at24_data *at24, char *buf, if (count > io_limit) count = io_limit; - if (at24->use_smbus) { + switch (at24->use_smbus) { + case I2C_SMBUS_I2C_BLOCK_DATA: /* Smaller eeproms can work given some SMBus extension calls */ if (count > I2C_SMBUS_BLOCK_MAX) count = I2C_SMBUS_BLOCK_MAX; - } else { + break; + case I2C_SMBUS_WORD_DATA: + count = 2; + break; + case I2C_SMBUS_BYTE_DATA: + count = 1; + break; + default: /* * When we have a better choice than SMBus calls, use a * combined I2C message. Write address; then read up to @@ -219,10 +227,27 @@ static ssize_t at24_eeprom_read(struct at24_data *at24, char *buf, timeout = jiffies + msecs_to_jiffies(write_timeout); do { read_time = jiffies; - if (at24->use_smbus) { + switch (at24->use_smbus) { + case I2C_SMBUS_I2C_BLOCK_DATA: status = i2c_smbus_read_i2c_block_data(client, offset, count, buf); - } else { + break; + case I2C_SMBUS_WORD_DATA: + status = i2c_smbus_read_word_data(client, offset); + if (status >= 0) { + buf[0] = status & 0xff; + buf[1] = status >> 8; + status = count; + } + break; + case I2C_SMBUS_BYTE_DATA: + status = i2c_smbus_read_byte_data(client, offset); + if (status >= 0) { + buf[0] = status; + status = count; + } + break; + default: status = i2c_transfer(client->adapter, msg, 2); if (status == 2) status = count; @@ -434,7 +459,7 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct at24_platform_data chip; bool writable; - bool use_smbus = false; + int use_smbus = 0; struct at24_data *at24; int err; unsigned i, num_addresses; @@ -475,12 +500,19 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) err = -EPFNOSUPPORT; goto err_out; } - if (!i2c_check_functionality(client->adapter, + if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) { + use_smbus = I2C_SMBUS_I2C_BLOCK_DATA; + } else if (i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_READ_WORD_DATA)) { + use_smbus = I2C_SMBUS_WORD_DATA; + } else if (i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_READ_BYTE_DATA)) { + use_smbus = I2C_SMBUS_BYTE_DATA; + } else { err = -EPFNOSUPPORT; goto err_out; } - use_smbus = true; } if (chip.flags & AT24_FLAG_TAKE8ADDR) @@ -505,6 +537,7 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) * Export the EEPROM bytes through sysfs, since that's convenient. * By default, only root should see the data (maybe passwords etc) */ + sysfs_bin_attr_init(&at24->bin); at24->bin.attr.name = "eeprom"; at24->bin.attr.mode = chip.flags & AT24_FLAG_IRUGO ? S_IRUGO : S_IRUSR; at24->bin.read = at24_bin_read; @@ -565,11 +598,16 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) dev_info(&client->dev, "%zu byte %s EEPROM %s\n", at24->bin.size, client->name, writable ? "(writable)" : "(read-only)"); + if (use_smbus == I2C_SMBUS_WORD_DATA || + use_smbus == I2C_SMBUS_BYTE_DATA) { + dev_notice(&client->dev, "Falling back to %s reads, " + "performance will suffer\n", use_smbus == + I2C_SMBUS_WORD_DATA ? "word" : "byte"); + } dev_dbg(&client->dev, - "page_size %d, num_addresses %d, write_max %d%s\n", + "page_size %d, num_addresses %d, write_max %d, use_smbus %d\n", chip.page_size, num_addresses, - at24->write_max, - use_smbus ? ", use_smbus" : ""); + at24->write_max, use_smbus); /* export data to kernel code */ if (chip.setup) diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c index d902d81dde39..d194212a41f6 100644 --- a/drivers/misc/eeprom/at25.c +++ b/drivers/misc/eeprom/at25.c @@ -347,6 +347,7 @@ static int at25_probe(struct spi_device *spi) * that's sensitive for read and/or write, like ethernet addresses, * security codes, board-specific manufacturing calibrations, etc. */ + sysfs_bin_attr_init(&at25->bin); at25->bin.attr.name = "eeprom"; at25->bin.attr.mode = S_IRUSR; at25->bin.read = at25_bin_read; diff --git a/drivers/misc/hwlat_detector.c b/drivers/misc/hwlat_detector.c new file mode 100644 index 000000000000..e02d8e17b484 --- /dev/null +++ b/drivers/misc/hwlat_detector.c @@ -0,0 +1,1208 @@ +/* + * hwlat_detector.c - A simple Hardware Latency detector. + * + * Use this module to detect large system latencies induced by the behavior of + * certain underlying system hardware or firmware, independent of Linux itself. + * The code was developed originally to detect the presence of SMIs on Intel + * and AMD systems, although there is no dependency upon x86 herein. + * + * The classical example usage of this module is in detecting the presence of + * SMIs or System Management Interrupts on Intel and AMD systems. An SMI is a + * somewhat special form of hardware interrupt spawned from earlier CPU debug + * modes in which the (BIOS/EFI/etc.) firmware arranges for the South Bridge + * LPC (or other device) to generate a special interrupt under certain + * circumstances, for example, upon expiration of a special SMI timer device, + * due to certain external thermal readings, on certain I/O address accesses, + * and other situations. An SMI hits a special CPU pin, triggers a special + * SMI mode (complete with special memory map), and the OS is unaware. + * + * Although certain hardware-inducing latencies are necessary (for example, + * a modern system often requires an SMI handler for correct thermal control + * and remote management) they can wreak havoc upon any OS-level performance + * guarantees toward low-latency, especially when the OS is not even made + * aware of the presence of these interrupts. For this reason, we need a + * somewhat brute force mechanism to detect these interrupts. In this case, + * we do it by hogging all of the CPU(s) for configurable timer intervals, + * sampling the built-in CPU timer, looking for discontiguous readings. + * + * WARNING: This implementation necessarily introduces latencies. Therefore, + * you should NEVER use this module in a production environment + * requiring any kind of low-latency performance guarantee(s). + * + * Copyright (C) 2008-2009 Jon Masters, Red Hat, Inc. <jcm@redhat.com> + * + * Includes useful feedback from Clark Williams <clark@redhat.com> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/ring_buffer.h> +#include <linux/stop_machine.h> +#include <linux/time.h> +#include <linux/hrtimer.h> +#include <linux/kthread.h> +#include <linux/debugfs.h> +#include <linux/seq_file.h> +#include <linux/uaccess.h> +#include <linux/version.h> +#include <linux/delay.h> + +#define BUF_SIZE_DEFAULT 262144UL /* 8K*(sizeof(entry)) */ +#define BUF_FLAGS (RB_FL_OVERWRITE) /* no block on full */ +#define U64STR_SIZE 22 /* 20 digits max */ + +#define VERSION "1.0.0" +#define BANNER "hwlat_detector: " +#define DRVNAME "hwlat_detector" +#define DEFAULT_SAMPLE_WINDOW 1000000 /* 1s */ +#define DEFAULT_SAMPLE_WIDTH 500000 /* 0.5s */ +#define DEFAULT_LAT_THRESHOLD 10 /* 10us */ + +/* Module metadata */ + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Jon Masters <jcm@redhat.com>"); +MODULE_DESCRIPTION("A simple hardware latency detector"); +MODULE_VERSION(VERSION); + +/* Module parameters */ + +static int debug; +static int enabled; +static int threshold; + +module_param(debug, int, 0); /* enable debug */ +module_param(enabled, int, 0); /* enable detector */ +module_param(threshold, int, 0); /* latency threshold */ + +/* Buffering and sampling */ + +static struct ring_buffer *ring_buffer; /* sample buffer */ +static DEFINE_MUTEX(ring_buffer_mutex); /* lock changes */ +static unsigned long buf_size = BUF_SIZE_DEFAULT; +static struct task_struct *kthread; /* sampling thread */ + +/* DebugFS filesystem entries */ + +static struct dentry *debug_dir; /* debugfs directory */ +static struct dentry *debug_max; /* maximum TSC delta */ +static struct dentry *debug_count; /* total detect count */ +static struct dentry *debug_sample_width; /* sample width us */ +static struct dentry *debug_sample_window; /* sample window us */ +static struct dentry *debug_sample; /* raw samples us */ +static struct dentry *debug_threshold; /* threshold us */ +static struct dentry *debug_enable; /* enable/disable */ + +/* Individual samples and global state */ + +struct sample; /* latency sample */ +struct data; /* Global state */ + +/* Sampling functions */ +static int __buffer_add_sample(struct sample *sample); +static struct sample *buffer_get_sample(struct sample *sample); +static int get_sample(void *unused); + +/* Threading and state */ +static int kthread_fn(void *unused); +static int start_kthread(void); +static int stop_kthread(void); +static void __reset_stats(void); +static int init_stats(void); + +/* Debugfs interface */ +static ssize_t simple_data_read(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos, const u64 *entry); +static ssize_t simple_data_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos, u64 *entry); +static int debug_sample_fopen(struct inode *inode, struct file *filp); +static ssize_t debug_sample_fread(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos); +static int debug_sample_release(struct inode *inode, struct file *filp); +static int debug_enable_fopen(struct inode *inode, struct file *filp); +static ssize_t debug_enable_fread(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos); +static ssize_t debug_enable_fwrite(struct file *file, + const char __user *user_buffer, + size_t user_size, loff_t *offset); + +/* Initialization functions */ +static int init_debugfs(void); +static void free_debugfs(void); +static int detector_init(void); +static void detector_exit(void); + +/* Individual latency samples are stored here when detected and packed into + * the ring_buffer circular buffer, where they are overwritten when + * more than buf_size/sizeof(sample) samples are received. */ +struct sample { + u64 seqnum; /* unique sequence */ + u64 duration; /* ktime delta */ + struct timespec timestamp; /* wall time */ +}; + +/* keep the global state somewhere. Mostly used under stop_machine. */ +static struct data { + + struct mutex lock; /* protect changes */ + + u64 count; /* total since reset */ + u64 max_sample; /* max hardware latency */ + u64 threshold; /* sample threshold level */ + + u64 sample_window; /* total sampling window (on+off) */ + u64 sample_width; /* active sampling portion of window */ + + atomic_t sample_open; /* whether the sample file is open */ + + wait_queue_head_t wq; /* waitqeue for new sample values */ + +} data; + +/** + * __buffer_add_sample - add a new latency sample recording to the ring buffer + * @sample: The new latency sample value + * + * This receives a new latency sample and records it in a global ring buffer. + * No additional locking is used in this case - suited for stop_machine use. + */ +static int __buffer_add_sample(struct sample *sample) +{ + return ring_buffer_write(ring_buffer, + sizeof(struct sample), sample); +} + +/** + * buffer_get_sample - remove a hardware latency sample from the ring buffer + * @sample: Pre-allocated storage for the sample + * + * This retrieves a hardware latency sample from the global circular buffer + */ +static struct sample *buffer_get_sample(struct sample *sample) +{ + struct ring_buffer_event *e = NULL; + struct sample *s = NULL; + unsigned int cpu = 0; + + if (!sample) + return NULL; + + /* ring_buffers are per-cpu but we just want any value */ + /* so we'll start with this cpu and try others if not */ + /* Steven is planning to add a generic mechanism */ + mutex_lock(&ring_buffer_mutex); + e = ring_buffer_consume(ring_buffer, smp_processor_id(), NULL); + if (!e) { + for_each_online_cpu(cpu) { + e = ring_buffer_consume(ring_buffer, cpu, NULL); + if (e) + break; + } + } + + if (e) { + s = ring_buffer_event_data(e); + memcpy(sample, s, sizeof(struct sample)); + } else + sample = NULL; + mutex_unlock(&ring_buffer_mutex); + + return sample; +} + +/** + * get_sample - sample the CPU TSC and look for likely hardware latencies + * @unused: This is not used but is a part of the stop_machine API + * + * Used to repeatedly capture the CPU TSC (or similar), looking for potential + * hardware-induced latency. Called under stop_machine, with data.lock held. + */ +static int get_sample(void *unused) +{ + ktime_t start, t1, t2; + s64 diff, total = 0; + u64 sample = 0; + int ret = 1; + + start = ktime_get(); /* start timestamp */ + + do { + + t1 = ktime_get(); /* we'll look for a discontinuity */ + t2 = ktime_get(); + + total = ktime_to_us(ktime_sub(t2, start)); /* sample width */ + diff = ktime_to_us(ktime_sub(t2, t1)); /* current diff */ + + /* This shouldn't happen */ + if (diff < 0) { + printk(KERN_ERR BANNER "time running backwards\n"); + goto out; + } + + if (diff > sample) + sample = diff; /* only want highest value */ + + } while (total <= data.sample_width); + + /* If we exceed the threshold value, we have found a hardware latency */ + if (sample > data.threshold) { + struct sample s; + + data.count++; + s.seqnum = data.count; + s.duration = sample; + s.timestamp = CURRENT_TIME; + __buffer_add_sample(&s); + + /* Keep a running maximum ever recorded hardware latency */ + if (sample > data.max_sample) + data.max_sample = sample; + + wake_up(&data.wq); /* wake up reader(s) */ + } + + ret = 0; +out: + return ret; +} + +/* + * kthread_fn - The CPU time sampling/hardware latency detection kernel thread + * @unused: A required part of the kthread API. + * + * Used to periodically sample the CPU TSC via a call to get_sample. We + * use stop_machine, whith does (intentionally) introduce latency since we + * need to ensure nothing else might be running (and thus pre-empting). + * Obviously this should never be used in production environments. + * + * stop_machine will schedule us typically only on CPU0 which is fine for + * almost every real-world hardware latency situation - but we might later + * generalize this if we find there are any actualy systems with alternate + * SMI delivery or other non CPU0 hardware latencies. + */ +static int kthread_fn(void *unused) +{ + int err = 0; + u64 interval = 0; + + while (!kthread_should_stop()) { + + mutex_lock(&data.lock); + + err = stop_machine(get_sample, unused, 0); + if (err) { + /* Houston, we have a problem */ + mutex_unlock(&data.lock); + goto err_out; + } + + interval = data.sample_window - data.sample_width; + do_div(interval, USEC_PER_MSEC); /* modifies interval value */ + + mutex_unlock(&data.lock); + + if (msleep_interruptible(interval)) + goto out; + } + goto out; +err_out: + printk(KERN_ERR BANNER "could not call stop_machine, disabling\n"); + enabled = 0; +out: + return err; + +} + +/** + * start_kthread - Kick off the hardware latency sampling/detector kthread + * + * This starts a kernel thread that will sit and sample the CPU timestamp + * counter (TSC or similar) and look for potential hardware latencies. + */ +static int start_kthread(void) +{ + kthread = kthread_run(kthread_fn, NULL, + DRVNAME); + if (IS_ERR(kthread)) { + printk(KERN_ERR BANNER "could not start sampling thread\n"); + enabled = 0; + return -ENOMEM; + } + + return 0; +} + +/** + * stop_kthread - Inform the hardware latency samping/detector kthread to stop + * + * This kicks the running hardware latency sampling/detector kernel thread and + * tells it to stop sampling now. Use this on unload and at system shutdown. + */ +static int stop_kthread(void) +{ + int ret; + + ret = kthread_stop(kthread); + + return ret; +} + +/** + * __reset_stats - Reset statistics for the hardware latency detector + * + * We use data to store various statistics and global state. We call this + * function in order to reset those when "enable" is toggled on or off, and + * also at initialization. Should be called with data.lock held. + */ +static void __reset_stats(void) +{ + data.count = 0; + data.max_sample = 0; + ring_buffer_reset(ring_buffer); /* flush out old sample entries */ +} + +/** + * init_stats - Setup global state statistics for the hardware latency detector + * + * We use data to store various statistics and global state. We also use + * a global ring buffer (ring_buffer) to keep raw samples of detected hardware + * induced system latencies. This function initializes these structures and + * allocates the global ring buffer also. + */ +static int init_stats(void) +{ + int ret = -ENOMEM; + + mutex_init(&data.lock); + init_waitqueue_head(&data.wq); + atomic_set(&data.sample_open, 0); + + ring_buffer = ring_buffer_alloc(buf_size, BUF_FLAGS); + + if (WARN(!ring_buffer, KERN_ERR BANNER + "failed to allocate ring buffer!\n")) + goto out; + + __reset_stats(); + data.threshold = DEFAULT_LAT_THRESHOLD; /* threshold us */ + data.sample_window = DEFAULT_SAMPLE_WINDOW; /* window us */ + data.sample_width = DEFAULT_SAMPLE_WIDTH; /* width us */ + + ret = 0; + +out: + return ret; + +} + +/* + * simple_data_read - Wrapper read function for global state debugfs entries + * @filp: The active open file structure for the debugfs "file" + * @ubuf: The userspace provided buffer to read value into + * @cnt: The maximum number of bytes to read + * @ppos: The current "file" position + * @entry: The entry to read from + * + * This function provides a generic read implementation for the global state + * "data" structure debugfs filesystem entries. It would be nice to use + * simple_attr_read directly, but we need to make sure that the data.lock + * spinlock is held during the actual read (even though we likely won't ever + * actually race here as the updater runs under a stop_machine context). + */ +static ssize_t simple_data_read(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos, const u64 *entry) +{ + char buf[U64STR_SIZE]; + u64 val = 0; + int len = 0; + + memset(buf, 0, sizeof(buf)); + + if (!entry) + return -EFAULT; + + mutex_lock(&data.lock); + val = *entry; + mutex_unlock(&data.lock); + + len = snprintf(buf, sizeof(buf), "%llu\n", (unsigned long long)val); + + return simple_read_from_buffer(ubuf, cnt, ppos, buf, len); + +} + +/* + * simple_data_write - Wrapper write function for global state debugfs entries + * @filp: The active open file structure for the debugfs "file" + * @ubuf: The userspace provided buffer to write value from + * @cnt: The maximum number of bytes to write + * @ppos: The current "file" position + * @entry: The entry to write to + * + * This function provides a generic write implementation for the global state + * "data" structure debugfs filesystem entries. It would be nice to use + * simple_attr_write directly, but we need to make sure that the data.lock + * spinlock is held during the actual write (even though we likely won't ever + * actually race here as the updater runs under a stop_machine context). + */ +static ssize_t simple_data_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *ppos, u64 *entry) +{ + char buf[U64STR_SIZE]; + int csize = min(cnt, sizeof(buf)); + u64 val = 0; + int err = 0; + + memset(buf, '\0', sizeof(buf)); + if (copy_from_user(buf, ubuf, csize)) + return -EFAULT; + + buf[U64STR_SIZE-1] = '\0'; /* just in case */ + err = strict_strtoull(buf, 10, &val); + if (err) + return -EINVAL; + + mutex_lock(&data.lock); + *entry = val; + mutex_unlock(&data.lock); + + return csize; +} + +/** + * debug_count_fopen - Open function for "count" debugfs entry + * @inode: The in-kernel inode representation of the debugfs "file" + * @filp: The active open file structure for the debugfs "file" + * + * This function provides an open implementation for the "count" debugfs + * interface to the hardware latency detector. + */ +static int debug_count_fopen(struct inode *inode, struct file *filp) +{ + return 0; +} + +/** + * debug_count_fread - Read function for "count" debugfs entry + * @filp: The active open file structure for the debugfs "file" + * @ubuf: The userspace provided buffer to read value into + * @cnt: The maximum number of bytes to read + * @ppos: The current "file" position + * + * This function provides a read implementation for the "count" debugfs + * interface to the hardware latency detector. Can be used to read the + * number of latency readings exceeding the configured threshold since + * the detector was last reset (e.g. by writing a zero into "count"). + */ +static ssize_t debug_count_fread(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + return simple_data_read(filp, ubuf, cnt, ppos, &data.count); +} + +/** + * debug_count_fwrite - Write function for "count" debugfs entry + * @filp: The active open file structure for the debugfs "file" + * @ubuf: The user buffer that contains the value to write + * @cnt: The maximum number of bytes to write to "file" + * @ppos: The current position in the debugfs "file" + * + * This function provides a write implementation for the "count" debugfs + * interface to the hardware latency detector. Can be used to write a + * desired value, especially to zero the total count. + */ +static ssize_t debug_count_fwrite(struct file *filp, + const char __user *ubuf, + size_t cnt, + loff_t *ppos) +{ + return simple_data_write(filp, ubuf, cnt, ppos, &data.count); +} + +/** + * debug_enable_fopen - Dummy open function for "enable" debugfs interface + * @inode: The in-kernel inode representation of the debugfs "file" + * @filp: The active open file structure for the debugfs "file" + * + * This function provides an open implementation for the "enable" debugfs + * interface to the hardware latency detector. + */ +static int debug_enable_fopen(struct inode *inode, struct file *filp) +{ + return 0; +} + +/** + * debug_enable_fread - Read function for "enable" debugfs interface + * @filp: The active open file structure for the debugfs "file" + * @ubuf: The userspace provided buffer to read value into + * @cnt: The maximum number of bytes to read + * @ppos: The current "file" position + * + * This function provides a read implementation for the "enable" debugfs + * interface to the hardware latency detector. Can be used to determine + * whether the detector is currently enabled ("0\n" or "1\n" returned). + */ +static ssize_t debug_enable_fread(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + char buf[4]; + + if ((cnt < sizeof(buf)) || (*ppos)) + return 0; + + buf[0] = enabled ? '1' : '0'; + buf[1] = '\n'; + buf[2] = '\0'; + if (copy_to_user(ubuf, buf, strlen(buf))) + return -EFAULT; + return *ppos = strlen(buf); +} + +/** + * debug_enable_fwrite - Write function for "enable" debugfs interface + * @filp: The active open file structure for the debugfs "file" + * @ubuf: The user buffer that contains the value to write + * @cnt: The maximum number of bytes to write to "file" + * @ppos: The current position in the debugfs "file" + * + * This function provides a write implementation for the "enable" debugfs + * interface to the hardware latency detector. Can be used to enable or + * disable the detector, which will have the side-effect of possibly + * also resetting the global stats and kicking off the measuring + * kthread (on an enable) or the converse (upon a disable). + */ +static ssize_t debug_enable_fwrite(struct file *filp, + const char __user *ubuf, + size_t cnt, + loff_t *ppos) +{ + char buf[4]; + int csize = min(cnt, sizeof(buf)); + long val = 0; + int err = 0; + + memset(buf, '\0', sizeof(buf)); + if (copy_from_user(buf, ubuf, csize)) + return -EFAULT; + + buf[sizeof(buf)-1] = '\0'; /* just in case */ + err = strict_strtoul(buf, 10, &val); + if (0 != err) + return -EINVAL; + + if (val) { + if (enabled) + goto unlock; + enabled = 1; + __reset_stats(); + if (start_kthread()) + return -EFAULT; + } else { + if (!enabled) + goto unlock; + enabled = 0; + stop_kthread(); + wake_up(&data.wq); /* reader(s) should return */ + } +unlock: + return csize; +} + +/** + * debug_max_fopen - Open function for "max" debugfs entry + * @inode: The in-kernel inode representation of the debugfs "file" + * @filp: The active open file structure for the debugfs "file" + * + * This function provides an open implementation for the "max" debugfs + * interface to the hardware latency detector. + */ +static int debug_max_fopen(struct inode *inode, struct file *filp) +{ + return 0; +} + +/** + * debug_max_fread - Read function for "max" debugfs entry + * @filp: The active open file structure for the debugfs "file" + * @ubuf: The userspace provided buffer to read value into + * @cnt: The maximum number of bytes to read + * @ppos: The current "file" position + * + * This function provides a read implementation for the "max" debugfs + * interface to the hardware latency detector. Can be used to determine + * the maximum latency value observed since it was last reset. + */ +static ssize_t debug_max_fread(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + return simple_data_read(filp, ubuf, cnt, ppos, &data.max_sample); +} + +/** + * debug_max_fwrite - Write function for "max" debugfs entry + * @filp: The active open file structure for the debugfs "file" + * @ubuf: The user buffer that contains the value to write + * @cnt: The maximum number of bytes to write to "file" + * @ppos: The current position in the debugfs "file" + * + * This function provides a write implementation for the "max" debugfs + * interface to the hardware latency detector. Can be used to reset the + * maximum or set it to some other desired value - if, then, subsequent + * measurements exceed this value, the maximum will be updated. + */ +static ssize_t debug_max_fwrite(struct file *filp, + const char __user *ubuf, + size_t cnt, + loff_t *ppos) +{ + return simple_data_write(filp, ubuf, cnt, ppos, &data.max_sample); +} + + +/** + * debug_sample_fopen - An open function for "sample" debugfs interface + * @inode: The in-kernel inode representation of this debugfs "file" + * @filp: The active open file structure for the debugfs "file" + * + * This function handles opening the "sample" file within the hardware + * latency detector debugfs directory interface. This file is used to read + * raw samples from the global ring_buffer and allows the user to see a + * running latency history. Can be opened blocking or non-blocking, + * affecting whether it behaves as a buffer read pipe, or does not. + * Implements simple locking to prevent multiple simultaneous use. + */ +static int debug_sample_fopen(struct inode *inode, struct file *filp) +{ + if (!atomic_add_unless(&data.sample_open, 1, 1)) + return -EBUSY; + else + return 0; +} + +/** + * debug_sample_fread - A read function for "sample" debugfs interface + * @filp: The active open file structure for the debugfs "file" + * @ubuf: The user buffer that will contain the samples read + * @cnt: The maximum bytes to read from the debugfs "file" + * @ppos: The current position in the debugfs "file" + * + * This function handles reading from the "sample" file within the hardware + * latency detector debugfs directory interface. This file is used to read + * raw samples from the global ring_buffer and allows the user to see a + * running latency history. By default this will block pending a new + * value written into the sample buffer, unless there are already a + * number of value(s) waiting in the buffer, or the sample file was + * previously opened in a non-blocking mode of operation. + */ +static ssize_t debug_sample_fread(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + int len = 0; + char buf[64]; + struct sample *sample = NULL; + + if (!enabled) + return 0; + + sample = kzalloc(sizeof(struct sample), GFP_KERNEL); + if (!sample) + return -ENOMEM; + + while (!buffer_get_sample(sample)) { + + DEFINE_WAIT(wait); + + if (filp->f_flags & O_NONBLOCK) { + len = -EAGAIN; + goto out; + } + + prepare_to_wait(&data.wq, &wait, TASK_INTERRUPTIBLE); + schedule(); + finish_wait(&data.wq, &wait); + + if (signal_pending(current)) { + len = -EINTR; + goto out; + } + + if (!enabled) { /* enable was toggled */ + len = 0; + goto out; + } + } + + len = snprintf(buf, sizeof(buf), "%010lu.%010lu\t%llu\n", + sample->timestamp.tv_sec, + sample->timestamp.tv_nsec, + sample->duration); + + + /* handling partial reads is more trouble than it's worth */ + if (len > cnt) + goto out; + + if (copy_to_user(ubuf, buf, len)) + len = -EFAULT; + +out: + kfree(sample); + return len; +} + +/** + * debug_sample_release - Release function for "sample" debugfs interface + * @inode: The in-kernel inode represenation of the debugfs "file" + * @filp: The active open file structure for the debugfs "file" + * + * This function completes the close of the debugfs interface "sample" file. + * Frees the sample_open "lock" so that other users may open the interface. + */ +static int debug_sample_release(struct inode *inode, struct file *filp) +{ + atomic_dec(&data.sample_open); + + return 0; +} + +/** + * debug_threshold_fopen - Open function for "threshold" debugfs entry + * @inode: The in-kernel inode representation of the debugfs "file" + * @filp: The active open file structure for the debugfs "file" + * + * This function provides an open implementation for the "threshold" debugfs + * interface to the hardware latency detector. + */ +static int debug_threshold_fopen(struct inode *inode, struct file *filp) +{ + return 0; +} + +/** + * debug_threshold_fread - Read function for "threshold" debugfs entry + * @filp: The active open file structure for the debugfs "file" + * @ubuf: The userspace provided buffer to read value into + * @cnt: The maximum number of bytes to read + * @ppos: The current "file" position + * + * This function provides a read implementation for the "threshold" debugfs + * interface to the hardware latency detector. It can be used to determine + * the current threshold level at which a latency will be recorded in the + * global ring buffer, typically on the order of 10us. + */ +static ssize_t debug_threshold_fread(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + return simple_data_read(filp, ubuf, cnt, ppos, &data.threshold); +} + +/** + * debug_threshold_fwrite - Write function for "threshold" debugfs entry + * @filp: The active open file structure for the debugfs "file" + * @ubuf: The user buffer that contains the value to write + * @cnt: The maximum number of bytes to write to "file" + * @ppos: The current position in the debugfs "file" + * + * This function provides a write implementation for the "threshold" debugfs + * interface to the hardware latency detector. It can be used to configure + * the threshold level at which any subsequently detected latencies will + * be recorded into the global ring buffer. + */ +static ssize_t debug_threshold_fwrite(struct file *filp, + const char __user *ubuf, + size_t cnt, + loff_t *ppos) +{ + int ret; + + ret = simple_data_write(filp, ubuf, cnt, ppos, &data.threshold); + + if (enabled) + wake_up_process(kthread); + + return ret; +} + +/** + * debug_width_fopen - Open function for "width" debugfs entry + * @inode: The in-kernel inode representation of the debugfs "file" + * @filp: The active open file structure for the debugfs "file" + * + * This function provides an open implementation for the "width" debugfs + * interface to the hardware latency detector. + */ +static int debug_width_fopen(struct inode *inode, struct file *filp) +{ + return 0; +} + +/** + * debug_width_fread - Read function for "width" debugfs entry + * @filp: The active open file structure for the debugfs "file" + * @ubuf: The userspace provided buffer to read value into + * @cnt: The maximum number of bytes to read + * @ppos: The current "file" position + * + * This function provides a read implementation for the "width" debugfs + * interface to the hardware latency detector. It can be used to determine + * for how many us of the total window us we will actively sample for any + * hardware-induced latecy periods. Obviously, it is not possible to + * sample constantly and have the system respond to a sample reader, or, + * worse, without having the system appear to have gone out to lunch. + */ +static ssize_t debug_width_fread(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + return simple_data_read(filp, ubuf, cnt, ppos, &data.sample_width); +} + +/** + * debug_width_fwrite - Write function for "width" debugfs entry + * @filp: The active open file structure for the debugfs "file" + * @ubuf: The user buffer that contains the value to write + * @cnt: The maximum number of bytes to write to "file" + * @ppos: The current position in the debugfs "file" + * + * This function provides a write implementation for the "width" debugfs + * interface to the hardware latency detector. It can be used to configure + * for how many us of the total window us we will actively sample for any + * hardware-induced latency periods. Obviously, it is not possible to + * sample constantly and have the system respond to a sample reader, or, + * worse, without having the system appear to have gone out to lunch. It + * is enforced that width is less that the total window size. + */ +static ssize_t debug_width_fwrite(struct file *filp, + const char __user *ubuf, + size_t cnt, + loff_t *ppos) +{ + char buf[U64STR_SIZE]; + int csize = min(cnt, sizeof(buf)); + u64 val = 0; + int err = 0; + + memset(buf, '\0', sizeof(buf)); + if (copy_from_user(buf, ubuf, csize)) + return -EFAULT; + + buf[U64STR_SIZE-1] = '\0'; /* just in case */ + err = strict_strtoull(buf, 10, &val); + if (0 != err) + return -EINVAL; + + mutex_lock(&data.lock); + if (val < data.sample_window) + data.sample_width = val; + else { + mutex_unlock(&data.lock); + return -EINVAL; + } + mutex_unlock(&data.lock); + + if (enabled) + wake_up_process(kthread); + + return csize; +} + +/** + * debug_window_fopen - Open function for "window" debugfs entry + * @inode: The in-kernel inode representation of the debugfs "file" + * @filp: The active open file structure for the debugfs "file" + * + * This function provides an open implementation for the "window" debugfs + * interface to the hardware latency detector. The window is the total time + * in us that will be considered one sample period. Conceptually, windows + * occur back-to-back and contain a sample width period during which + * actual sampling occurs. + */ +static int debug_window_fopen(struct inode *inode, struct file *filp) +{ + return 0; +} + +/** + * debug_window_fread - Read function for "window" debugfs entry + * @filp: The active open file structure for the debugfs "file" + * @ubuf: The userspace provided buffer to read value into + * @cnt: The maximum number of bytes to read + * @ppos: The current "file" position + * + * This function provides a read implementation for the "window" debugfs + * interface to the hardware latency detector. The window is the total time + * in us that will be considered one sample period. Conceptually, windows + * occur back-to-back and contain a sample width period during which + * actual sampling occurs. Can be used to read the total window size. + */ +static ssize_t debug_window_fread(struct file *filp, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + return simple_data_read(filp, ubuf, cnt, ppos, &data.sample_window); +} + +/** + * debug_window_fwrite - Write function for "window" debugfs entry + * @filp: The active open file structure for the debugfs "file" + * @ubuf: The user buffer that contains the value to write + * @cnt: The maximum number of bytes to write to "file" + * @ppos: The current position in the debugfs "file" + * + * This function provides a write implementation for the "window" debufds + * interface to the hardware latency detetector. The window is the total time + * in us that will be considered one sample period. Conceptually, windows + * occur back-to-back and contain a sample width period during which + * actual sampling occurs. Can be used to write a new total window size. It + * is enfoced that any value written must be greater than the sample width + * size, or an error results. + */ +static ssize_t debug_window_fwrite(struct file *filp, + const char __user *ubuf, + size_t cnt, + loff_t *ppos) +{ + char buf[U64STR_SIZE]; + int csize = min(cnt, sizeof(buf)); + u64 val = 0; + int err = 0; + + memset(buf, '\0', sizeof(buf)); + if (copy_from_user(buf, ubuf, csize)) + return -EFAULT; + + buf[U64STR_SIZE-1] = '\0'; /* just in case */ + err = strict_strtoull(buf, 10, &val); + if (0 != err) + return -EINVAL; + + mutex_lock(&data.lock); + if (data.sample_width < val) + data.sample_window = val; + else { + mutex_unlock(&data.lock); + return -EINVAL; + } + mutex_unlock(&data.lock); + + return csize; +} + +/* + * Function pointers for the "count" debugfs file operations + */ +static const struct file_operations count_fops = { + .open = debug_count_fopen, + .read = debug_count_fread, + .write = debug_count_fwrite, + .owner = THIS_MODULE, +}; + +/* + * Function pointers for the "enable" debugfs file operations + */ +static const struct file_operations enable_fops = { + .open = debug_enable_fopen, + .read = debug_enable_fread, + .write = debug_enable_fwrite, + .owner = THIS_MODULE, +}; + +/* + * Function pointers for the "max" debugfs file operations + */ +static const struct file_operations max_fops = { + .open = debug_max_fopen, + .read = debug_max_fread, + .write = debug_max_fwrite, + .owner = THIS_MODULE, +}; + +/* + * Function pointers for the "sample" debugfs file operations + */ +static const struct file_operations sample_fops = { + .open = debug_sample_fopen, + .read = debug_sample_fread, + .release = debug_sample_release, + .owner = THIS_MODULE, +}; + +/* + * Function pointers for the "threshold" debugfs file operations + */ +static const struct file_operations threshold_fops = { + .open = debug_threshold_fopen, + .read = debug_threshold_fread, + .write = debug_threshold_fwrite, + .owner = THIS_MODULE, +}; + +/* + * Function pointers for the "width" debugfs file operations + */ +static const struct file_operations width_fops = { + .open = debug_width_fopen, + .read = debug_width_fread, + .write = debug_width_fwrite, + .owner = THIS_MODULE, +}; + +/* + * Function pointers for the "window" debugfs file operations + */ +static const struct file_operations window_fops = { + .open = debug_window_fopen, + .read = debug_window_fread, + .write = debug_window_fwrite, + .owner = THIS_MODULE, +}; + +/** + * init_debugfs - A function to initialize the debugfs interface files + * + * This function creates entries in debugfs for "hwlat_detector", including + * files to read values from the detector, current samples, and the + * maximum sample that has been captured since the hardware latency + * dectector was started. + */ +static int init_debugfs(void) +{ + int ret = -ENOMEM; + + debug_dir = debugfs_create_dir(DRVNAME, NULL); + if (!debug_dir) + goto err_debug_dir; + + debug_sample = debugfs_create_file("sample", 0444, + debug_dir, NULL, + &sample_fops); + if (!debug_sample) + goto err_sample; + + debug_count = debugfs_create_file("count", 0444, + debug_dir, NULL, + &count_fops); + if (!debug_count) + goto err_count; + + debug_max = debugfs_create_file("max", 0444, + debug_dir, NULL, + &max_fops); + if (!debug_max) + goto err_max; + + debug_sample_window = debugfs_create_file("window", 0644, + debug_dir, NULL, + &window_fops); + if (!debug_sample_window) + goto err_window; + + debug_sample_width = debugfs_create_file("width", 0644, + debug_dir, NULL, + &width_fops); + if (!debug_sample_width) + goto err_width; + + debug_threshold = debugfs_create_file("threshold", 0644, + debug_dir, NULL, + &threshold_fops); + if (!debug_threshold) + goto err_threshold; + + debug_enable = debugfs_create_file("enable", 0644, + debug_dir, &enabled, + &enable_fops); + if (!debug_enable) + goto err_enable; + + else { + ret = 0; + goto out; + } + +err_enable: + debugfs_remove(debug_threshold); +err_threshold: + debugfs_remove(debug_sample_width); +err_width: + debugfs_remove(debug_sample_window); +err_window: + debugfs_remove(debug_max); +err_max: + debugfs_remove(debug_count); +err_count: + debugfs_remove(debug_sample); +err_sample: + debugfs_remove(debug_dir); +err_debug_dir: +out: + return ret; +} + +/** + * free_debugfs - A function to cleanup the debugfs file interface + */ +static void free_debugfs(void) +{ + /* could also use a debugfs_remove_recursive */ + debugfs_remove(debug_enable); + debugfs_remove(debug_threshold); + debugfs_remove(debug_sample_width); + debugfs_remove(debug_sample_window); + debugfs_remove(debug_max); + debugfs_remove(debug_count); + debugfs_remove(debug_sample); + debugfs_remove(debug_dir); +} + +/** + * detector_init - Standard module initialization code + */ +static int detector_init(void) +{ + int ret = -ENOMEM; + + printk(KERN_INFO BANNER "version %s\n", VERSION); + + ret = init_stats(); + if (0 != ret) + goto out; + + ret = init_debugfs(); + if (0 != ret) + goto err_stats; + + if (enabled) + ret = start_kthread(); + + goto out; + +err_stats: + ring_buffer_free(ring_buffer); +out: + return ret; + +} + +/** + * detector_exit - Standard module cleanup code + */ +static void detector_exit(void) +{ + if (enabled) { + enabled = 0; + stop_kthread(); + } + + free_debugfs(); + ring_buffer_free(ring_buffer); /* free up the ring buffer */ + +} + +module_init(detector_init); +module_exit(detector_exit); diff --git a/drivers/misc/kgdbts.c b/drivers/misc/kgdbts.c index fcb6ec1af173..72450237a0f4 100644 --- a/drivers/misc/kgdbts.c +++ b/drivers/misc/kgdbts.c @@ -295,6 +295,10 @@ static int check_and_rewind_pc(char *put_str, char *arg) /* On x86 a breakpoint stop requires it to be decremented */ if (addr + 1 == kgdbts_regs.ip) offset = -1; +#elif defined(CONFIG_SUPERH) + /* On SUPERH a breakpoint stop requires it to be decremented */ + if (addr + 2 == kgdbts_regs.pc) + offset = -2; #endif if (strcmp(arg, "silent") && instruction_pointer(&kgdbts_regs) + offset != addr) { @@ -305,6 +309,8 @@ static int check_and_rewind_pc(char *put_str, char *arg) #ifdef CONFIG_X86 /* On x86 adjust the instruction pointer if needed */ kgdbts_regs.ip += offset; +#elif defined(CONFIG_SUPERH) + kgdbts_regs.pc += offset; #endif return 0; } diff --git a/drivers/misc/sgi-gru/grutables.h b/drivers/misc/sgi-gru/grutables.h index 02a77b8b8eef..7a8b9068ea03 100644 --- a/drivers/misc/sgi-gru/grutables.h +++ b/drivers/misc/sgi-gru/grutables.h @@ -516,8 +516,7 @@ struct gru_blade_state { /* Scan all active GRUs in a GRU bitmap */ #define for_each_gru_in_bitmap(gid, map) \ - for ((gid) = find_first_bit((map), GRU_MAX_GRUS); (gid) < GRU_MAX_GRUS;\ - (gid)++, (gid) = find_next_bit((map), GRU_MAX_GRUS, (gid))) + for_each_set_bit((gid), (map), GRU_MAX_GRUS) /* Scan all active GRUs on a specific blade */ #define for_each_gru_on_blade(gru, nid, i) \ @@ -536,23 +535,17 @@ struct gru_blade_state { /* Scan each CBR whose bit is set in a TFM (or copy of) */ #define for_each_cbr_in_tfm(i, map) \ - for ((i) = find_first_bit(map, GRU_NUM_CBE); \ - (i) < GRU_NUM_CBE; \ - (i)++, (i) = find_next_bit(map, GRU_NUM_CBE, i)) + for_each_set_bit((i), (map), GRU_NUM_CBE) /* Scan each CBR in a CBR bitmap. Note: multiple CBRs in an allocation unit */ #define for_each_cbr_in_allocation_map(i, map, k) \ - for ((k) = find_first_bit(map, GRU_CBR_AU); (k) < GRU_CBR_AU; \ - (k) = find_next_bit(map, GRU_CBR_AU, (k) + 1)) \ + for_each_set_bit((k), (map), GRU_CBR_AU) \ for ((i) = (k)*GRU_CBR_AU_SIZE; \ (i) < ((k) + 1) * GRU_CBR_AU_SIZE; (i)++) /* Scan each DSR in a DSR bitmap. Note: multiple DSRs in an allocation unit */ #define for_each_dsr_in_allocation_map(i, map, k) \ - for ((k) = find_first_bit((const unsigned long *)map, GRU_DSR_AU);\ - (k) < GRU_DSR_AU; \ - (k) = find_next_bit((const unsigned long *)map, \ - GRU_DSR_AU, (k) + 1)) \ + for_each_set_bit((k), (const unsigned long *)(map), GRU_DSR_AU) \ for ((i) = (k) * GRU_DSR_AU_CL; \ (i) < ((k) + 1) * GRU_DSR_AU_CL; (i)++) diff --git a/drivers/misc/tsl2550.c b/drivers/misc/tsl2550.c new file mode 100644 index 000000000000..483ae5f7f68e --- /dev/null +++ b/drivers/misc/tsl2550.c @@ -0,0 +1,473 @@ +/* + * tsl2550.c - Linux kernel modules for ambient light sensor + * + * Copyright (C) 2007 Rodolfo Giometti <giometti@linux.it> + * Copyright (C) 2007 Eurotech S.p.A. <info@eurotech.it> + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/i2c.h> +#include <linux/mutex.h> + +#define TSL2550_DRV_NAME "tsl2550" +#define DRIVER_VERSION "1.2" + +/* + * Defines + */ + +#define TSL2550_POWER_DOWN 0x00 +#define TSL2550_POWER_UP 0x03 +#define TSL2550_STANDARD_RANGE 0x18 +#define TSL2550_EXTENDED_RANGE 0x1d +#define TSL2550_READ_ADC0 0x43 +#define TSL2550_READ_ADC1 0x83 + +/* + * Structs + */ + +struct tsl2550_data { + struct i2c_client *client; + struct mutex update_lock; + + unsigned int power_state:1; + unsigned int operating_mode:1; +}; + +/* + * Global data + */ + +static const u8 TSL2550_MODE_RANGE[2] = { + TSL2550_STANDARD_RANGE, TSL2550_EXTENDED_RANGE, +}; + +/* + * Management functions + */ + +static int tsl2550_set_operating_mode(struct i2c_client *client, int mode) +{ + struct tsl2550_data *data = i2c_get_clientdata(client); + + int ret = i2c_smbus_write_byte(client, TSL2550_MODE_RANGE[mode]); + + data->operating_mode = mode; + + return ret; +} + +static int tsl2550_set_power_state(struct i2c_client *client, int state) +{ + struct tsl2550_data *data = i2c_get_clientdata(client); + int ret; + + if (state == 0) + ret = i2c_smbus_write_byte(client, TSL2550_POWER_DOWN); + else { + ret = i2c_smbus_write_byte(client, TSL2550_POWER_UP); + + /* On power up we should reset operating mode also... */ + tsl2550_set_operating_mode(client, data->operating_mode); + } + + data->power_state = state; + + return ret; +} + +static int tsl2550_get_adc_value(struct i2c_client *client, u8 cmd) +{ + int ret; + + ret = i2c_smbus_read_byte_data(client, cmd); + if (ret < 0) + return ret; + if (!(ret & 0x80)) + return -EAGAIN; + return ret & 0x7f; /* remove the "valid" bit */ +} + +/* + * LUX calculation + */ + +#define TSL2550_MAX_LUX 1846 + +static const u8 ratio_lut[] = { + 100, 100, 100, 100, 100, 100, 100, 100, + 100, 100, 100, 100, 100, 100, 99, 99, + 99, 99, 99, 99, 99, 99, 99, 99, + 99, 99, 99, 98, 98, 98, 98, 98, + 98, 98, 97, 97, 97, 97, 97, 96, + 96, 96, 96, 95, 95, 95, 94, 94, + 93, 93, 93, 92, 92, 91, 91, 90, + 89, 89, 88, 87, 87, 86, 85, 84, + 83, 82, 81, 80, 79, 78, 77, 75, + 74, 73, 71, 69, 68, 66, 64, 62, + 60, 58, 56, 54, 52, 49, 47, 44, + 42, 41, 40, 40, 39, 39, 38, 38, + 37, 37, 37, 36, 36, 36, 35, 35, + 35, 35, 34, 34, 34, 34, 33, 33, + 33, 33, 32, 32, 32, 32, 32, 31, + 31, 31, 31, 31, 30, 30, 30, 30, + 30, +}; + +static const u16 count_lut[] = { + 0, 1, 2, 3, 4, 5, 6, 7, + 8, 9, 10, 11, 12, 13, 14, 15, + 16, 18, 20, 22, 24, 26, 28, 30, + 32, 34, 36, 38, 40, 42, 44, 46, + 49, 53, 57, 61, 65, 69, 73, 77, + 81, 85, 89, 93, 97, 101, 105, 109, + 115, 123, 131, 139, 147, 155, 163, 171, + 179, 187, 195, 203, 211, 219, 227, 235, + 247, 263, 279, 295, 311, 327, 343, 359, + 375, 391, 407, 423, 439, 455, 471, 487, + 511, 543, 575, 607, 639, 671, 703, 735, + 767, 799, 831, 863, 895, 927, 959, 991, + 1039, 1103, 1167, 1231, 1295, 1359, 1423, 1487, + 1551, 1615, 1679, 1743, 1807, 1871, 1935, 1999, + 2095, 2223, 2351, 2479, 2607, 2735, 2863, 2991, + 3119, 3247, 3375, 3503, 3631, 3759, 3887, 4015, +}; + +/* + * This function is described into Taos TSL2550 Designer's Notebook + * pages 2, 3. + */ +static int tsl2550_calculate_lux(u8 ch0, u8 ch1) +{ + unsigned int lux; + + /* Look up count from channel values */ + u16 c0 = count_lut[ch0]; + u16 c1 = count_lut[ch1]; + + /* + * Calculate ratio. + * Note: the "128" is a scaling factor + */ + u8 r = 128; + + /* Avoid division by 0 and count 1 cannot be greater than count 0 */ + if (c1 <= c0) + if (c0) { + r = c1 * 128 / c0; + + /* Calculate LUX */ + lux = ((c0 - c1) * ratio_lut[r]) / 256; + } else + lux = 0; + else + return -EAGAIN; + + /* LUX range check */ + return lux > TSL2550_MAX_LUX ? TSL2550_MAX_LUX : lux; +} + +/* + * SysFS support + */ + +static ssize_t tsl2550_show_power_state(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev)); + + return sprintf(buf, "%u\n", data->power_state); +} + +static ssize_t tsl2550_store_power_state(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + struct i2c_client *client = to_i2c_client(dev); + struct tsl2550_data *data = i2c_get_clientdata(client); + unsigned long val = simple_strtoul(buf, NULL, 10); + int ret; + + if (val < 0 || val > 1) + return -EINVAL; + + mutex_lock(&data->update_lock); + ret = tsl2550_set_power_state(client, val); + mutex_unlock(&data->update_lock); + + if (ret < 0) + return ret; + + return count; +} + +static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO, + tsl2550_show_power_state, tsl2550_store_power_state); + +static ssize_t tsl2550_show_operating_mode(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev)); + + return sprintf(buf, "%u\n", data->operating_mode); +} + +static ssize_t tsl2550_store_operating_mode(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + struct i2c_client *client = to_i2c_client(dev); + struct tsl2550_data *data = i2c_get_clientdata(client); + unsigned long val = simple_strtoul(buf, NULL, 10); + int ret; + + if (val < 0 || val > 1) + return -EINVAL; + + if (data->power_state == 0) + return -EBUSY; + + mutex_lock(&data->update_lock); + ret = tsl2550_set_operating_mode(client, val); + mutex_unlock(&data->update_lock); + + if (ret < 0) + return ret; + + return count; +} + +static DEVICE_ATTR(operating_mode, S_IWUSR | S_IRUGO, + tsl2550_show_operating_mode, tsl2550_store_operating_mode); + +static ssize_t __tsl2550_show_lux(struct i2c_client *client, char *buf) +{ + struct tsl2550_data *data = i2c_get_clientdata(client); + u8 ch0, ch1; + int ret; + + ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC0); + if (ret < 0) + return ret; + ch0 = ret; + + ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC1); + if (ret < 0) + return ret; + ch1 = ret; + + /* Do the job */ + ret = tsl2550_calculate_lux(ch0, ch1); + if (ret < 0) + return ret; + if (data->operating_mode == 1) + ret *= 5; + + return sprintf(buf, "%d\n", ret); +} + +static ssize_t tsl2550_show_lux1_input(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct i2c_client *client = to_i2c_client(dev); + struct tsl2550_data *data = i2c_get_clientdata(client); + int ret; + + /* No LUX data if not operational */ + if (!data->power_state) + return -EBUSY; + + mutex_lock(&data->update_lock); + ret = __tsl2550_show_lux(client, buf); + mutex_unlock(&data->update_lock); + + return ret; +} + +static DEVICE_ATTR(lux1_input, S_IRUGO, + tsl2550_show_lux1_input, NULL); + +static struct attribute *tsl2550_attributes[] = { + &dev_attr_power_state.attr, + &dev_attr_operating_mode.attr, + &dev_attr_lux1_input.attr, + NULL +}; + +static const struct attribute_group tsl2550_attr_group = { + .attrs = tsl2550_attributes, +}; + +/* + * Initialization function + */ + +static int tsl2550_init_client(struct i2c_client *client) +{ + struct tsl2550_data *data = i2c_get_clientdata(client); + int err; + + /* + * Probe the chip. To do so we try to power up the device and then to + * read back the 0x03 code + */ + err = i2c_smbus_read_byte_data(client, TSL2550_POWER_UP); + if (err < 0) + return err; + if (err != TSL2550_POWER_UP) + return -ENODEV; + data->power_state = 1; + + /* Set the default operating mode */ + err = i2c_smbus_write_byte(client, + TSL2550_MODE_RANGE[data->operating_mode]); + if (err < 0) + return err; + + return 0; +} + +/* + * I2C init/probing/exit functions + */ + +static struct i2c_driver tsl2550_driver; +static int __devinit tsl2550_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); + struct tsl2550_data *data; + int *opmode, err = 0; + + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE + | I2C_FUNC_SMBUS_READ_BYTE_DATA)) { + err = -EIO; + goto exit; + } + + data = kzalloc(sizeof(struct tsl2550_data), GFP_KERNEL); + if (!data) { + err = -ENOMEM; + goto exit; + } + data->client = client; + i2c_set_clientdata(client, data); + + /* Check platform data */ + opmode = client->dev.platform_data; + if (opmode) { + if (*opmode < 0 || *opmode > 1) { + dev_err(&client->dev, "invalid operating_mode (%d)\n", + *opmode); + err = -EINVAL; + goto exit_kfree; + } + data->operating_mode = *opmode; + } else + data->operating_mode = 0; /* default mode is standard */ + dev_info(&client->dev, "%s operating mode\n", + data->operating_mode ? "extended" : "standard"); + + mutex_init(&data->update_lock); + + /* Initialize the TSL2550 chip */ + err = tsl2550_init_client(client); + if (err) + goto exit_kfree; + + /* Register sysfs hooks */ + err = sysfs_create_group(&client->dev.kobj, &tsl2550_attr_group); + if (err) + goto exit_kfree; + + dev_info(&client->dev, "support ver. %s enabled\n", DRIVER_VERSION); + + return 0; + +exit_kfree: + kfree(data); +exit: + return err; +} + +static int __devexit tsl2550_remove(struct i2c_client *client) +{ + sysfs_remove_group(&client->dev.kobj, &tsl2550_attr_group); + + /* Power down the device */ + tsl2550_set_power_state(client, 0); + + kfree(i2c_get_clientdata(client)); + + return 0; +} + +#ifdef CONFIG_PM + +static int tsl2550_suspend(struct i2c_client *client, pm_message_t mesg) +{ + return tsl2550_set_power_state(client, 0); +} + +static int tsl2550_resume(struct i2c_client *client) +{ + return tsl2550_set_power_state(client, 1); +} + +#else + +#define tsl2550_suspend NULL +#define tsl2550_resume NULL + +#endif /* CONFIG_PM */ + +static const struct i2c_device_id tsl2550_id[] = { + { "tsl2550", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, tsl2550_id); + +static struct i2c_driver tsl2550_driver = { + .driver = { + .name = TSL2550_DRV_NAME, + .owner = THIS_MODULE, + }, + .suspend = tsl2550_suspend, + .resume = tsl2550_resume, + .probe = tsl2550_probe, + .remove = __devexit_p(tsl2550_remove), + .id_table = tsl2550_id, +}; + +static int __init tsl2550_init(void) +{ + return i2c_add_driver(&tsl2550_driver); +} + +static void __exit tsl2550_exit(void) +{ + i2c_del_driver(&tsl2550_driver); +} + +MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>"); +MODULE_DESCRIPTION("TSL2550 ambient light sensor driver"); +MODULE_LICENSE("GPL"); +MODULE_VERSION(DRIVER_VERSION); + +module_init(tsl2550_init); +module_exit(tsl2550_exit); |