diff options
Diffstat (limited to 'sound/drivers/pcmtest.c')
| -rw-r--r-- | sound/drivers/pcmtest.c | 778 |
1 files changed, 778 insertions, 0 deletions
diff --git a/sound/drivers/pcmtest.c b/sound/drivers/pcmtest.c new file mode 100644 index 0000000000..b8bff5522b --- /dev/null +++ b/sound/drivers/pcmtest.c @@ -0,0 +1,778 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Virtual ALSA driver for PCM testing/fuzzing + * + * Copyright 2023 Ivan Orlov <ivan.orlov0322@gmail.com> + * + * This is a simple virtual ALSA driver, which can be used for audio applications/PCM middle layer + * testing or fuzzing. + * It can: + * - Simulate 'playback' and 'capture' actions + * - Generate random or pattern-based capture data + * - Check playback buffer for containing looped template, and notify about the results + * through the debugfs entry + * - Inject delays into the playback and capturing processes. See 'inject_delay' parameter. + * - Inject errors during the PCM callbacks. + * - Register custom RESET ioctl and notify when it is called through the debugfs entry + * - Work in interleaved and non-interleaved modes + * - Support up to 8 substreams + * - Support up to 4 channels + * - Support framerates from 8 kHz to 48 kHz + * + * When driver works in the capture mode with multiple channels, it duplicates the looped + * pattern to each separate channel. For example, if we have 2 channels, format = U8, interleaved + * access mode and pattern 'abacaba', the DMA buffer will look like aabbccaabbaaaa..., so buffer for + * each channel will contain abacabaabacaba... Same for the non-interleaved mode. + * + * However, it may break the capturing on the higher framerates with small period size, so it is + * better to choose larger period sizes. + * + * You can find the corresponding selftest in the 'alsa' selftests folder. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <sound/pcm.h> +#include <sound/core.h> +#include <linux/dma-mapping.h> +#include <linux/platform_device.h> +#include <linux/timer.h> +#include <linux/random.h> +#include <linux/debugfs.h> +#include <linux/delay.h> + +#define TIMER_PER_SEC 5 +#define TIMER_INTERVAL (HZ / TIMER_PER_SEC) +#define DELAY_JIFFIES HZ +#define PLAYBACK_SUBSTREAM_CNT 8 +#define CAPTURE_SUBSTREAM_CNT 8 +#define MAX_CHANNELS_NUM 4 + +#define DEFAULT_PATTERN "abacaba" +#define DEFAULT_PATTERN_LEN 7 + +#define FILL_MODE_RAND 0 +#define FILL_MODE_PAT 1 + +#define MAX_PATTERN_LEN 4096 + +static int index = -1; +static char *id = "pcmtest"; +static bool enable = true; +static int inject_delay; +static bool inject_hwpars_err; +static bool inject_prepare_err; +static bool inject_trigger_err; +static bool inject_open_err; + +static short fill_mode = FILL_MODE_PAT; + +static u8 playback_capture_test; +static u8 ioctl_reset_test; +static struct dentry *driver_debug_dir; + +module_param(index, int, 0444); +MODULE_PARM_DESC(index, "Index value for pcmtest soundcard"); +module_param(id, charp, 0444); +MODULE_PARM_DESC(id, "ID string for pcmtest soundcard"); +module_param(enable, bool, 0444); +MODULE_PARM_DESC(enable, "Enable pcmtest soundcard."); +module_param(fill_mode, short, 0600); +MODULE_PARM_DESC(fill_mode, "Buffer fill mode: rand(0) or pattern(1)"); +module_param(inject_delay, int, 0600); +MODULE_PARM_DESC(inject_delay, "Inject delays during playback/capture (in jiffies)"); +module_param(inject_hwpars_err, bool, 0600); +MODULE_PARM_DESC(inject_hwpars_err, "Inject EBUSY error in the 'hw_params' callback"); +module_param(inject_prepare_err, bool, 0600); +MODULE_PARM_DESC(inject_prepare_err, "Inject EINVAL error in the 'prepare' callback"); +module_param(inject_trigger_err, bool, 0600); +MODULE_PARM_DESC(inject_trigger_err, "Inject EINVAL error in the 'trigger' callback"); +module_param(inject_open_err, bool, 0600); +MODULE_PARM_DESC(inject_open_err, "Inject EBUSY error in the 'open' callback"); + +struct pcmtst { + struct snd_pcm *pcm; + struct snd_card *card; + struct platform_device *pdev; +}; + +struct pcmtst_buf_iter { + size_t buf_pos; // position in the DMA buffer + size_t period_pos; // period-relative position + size_t b_rw; // Bytes to write on every timer tick + size_t s_rw_ch; // Samples to write to one channel on every tick + unsigned int sample_bytes; // sample_bits / 8 + bool is_buf_corrupted; // playback test result indicator + size_t period_bytes; // bytes in a one period + bool interleaved; // Interleaved/Non-interleaved mode + size_t total_bytes; // Total bytes read/written + size_t chan_block; // Bytes in one channel buffer when non-interleaved + struct snd_pcm_substream *substream; + bool suspend; // We need to pause timer without shutting it down + struct timer_list timer_instance; +}; + +static struct snd_pcm_hardware snd_pcmtst_hw = { + .info = (SNDRV_PCM_INFO_INTERLEAVED | + SNDRV_PCM_INFO_BLOCK_TRANSFER | + SNDRV_PCM_INFO_NONINTERLEAVED | + SNDRV_PCM_INFO_MMAP_VALID | + SNDRV_PCM_INFO_PAUSE), + .formats = SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S16_LE, + .rates = SNDRV_PCM_RATE_8000_48000, + .rate_min = 8000, + .rate_max = 48000, + .channels_min = 1, + .channels_max = MAX_CHANNELS_NUM, + .buffer_bytes_max = 128 * 1024, + .period_bytes_min = 4096, + .period_bytes_max = 32768, + .periods_min = 1, + .periods_max = 1024, +}; + +struct pattern_buf { + char *buf; + u32 len; +}; + +static int buf_allocated; +static struct pattern_buf patt_bufs[MAX_CHANNELS_NUM]; + +static inline void inc_buf_pos(struct pcmtst_buf_iter *v_iter, size_t by, size_t bytes) +{ + v_iter->total_bytes += by; + v_iter->buf_pos += by; + if (v_iter->buf_pos >= bytes) + v_iter->buf_pos %= bytes; +} + +/* + * Position in the DMA buffer when we are in the non-interleaved mode. We increment buf_pos + * every time we write a byte to any channel, so the position in the current channel buffer is + * (position in the DMA buffer) / count_of_channels + size_of_channel_buf * current_channel + */ +static inline size_t buf_pos_n(struct pcmtst_buf_iter *v_iter, unsigned int channels, + unsigned int chan_num) +{ + return v_iter->buf_pos / channels + v_iter->chan_block * chan_num; +} + +/* + * Get the count of bytes written for the current channel in the interleaved mode. + * This is (count of samples written for the current channel) * bytes_in_sample + + * (relative position in the current sample) + */ +static inline size_t ch_pos_i(size_t b_total, unsigned int channels, unsigned int b_sample) +{ + return b_total / channels / b_sample * b_sample + (b_total % b_sample); +} + +static void check_buf_block_i(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime) +{ + size_t i; + short ch_num; + u8 current_byte; + + for (i = 0; i < v_iter->b_rw; i++) { + current_byte = runtime->dma_area[v_iter->buf_pos]; + if (!current_byte) + break; + ch_num = (v_iter->total_bytes / v_iter->sample_bytes) % runtime->channels; + if (current_byte != patt_bufs[ch_num].buf[ch_pos_i(v_iter->total_bytes, + runtime->channels, + v_iter->sample_bytes) + % patt_bufs[ch_num].len]) { + v_iter->is_buf_corrupted = true; + break; + } + inc_buf_pos(v_iter, 1, runtime->dma_bytes); + } + // If we broke during the loop, add remaining bytes to the buffer position. + inc_buf_pos(v_iter, v_iter->b_rw - i, runtime->dma_bytes); +} + +static void check_buf_block_ni(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime) +{ + unsigned int channels = runtime->channels; + size_t i; + short ch_num; + u8 current_byte; + + for (i = 0; i < v_iter->b_rw; i++) { + ch_num = i % channels; + current_byte = runtime->dma_area[buf_pos_n(v_iter, channels, ch_num)]; + if (!current_byte) + break; + if (current_byte != patt_bufs[ch_num].buf[(v_iter->total_bytes / channels) + % patt_bufs[ch_num].len]) { + v_iter->is_buf_corrupted = true; + break; + } + inc_buf_pos(v_iter, 1, runtime->dma_bytes); + } + inc_buf_pos(v_iter, v_iter->b_rw - i, runtime->dma_bytes); +} + +/* + * Check one block of the buffer. Here we iterate the buffer until we find '0'. This condition is + * necessary because we need to detect when the reading/writing ends, so we assume that the pattern + * doesn't contain zeros. + */ +static void check_buf_block(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime) +{ + if (v_iter->interleaved) + check_buf_block_i(v_iter, runtime); + else + check_buf_block_ni(v_iter, runtime); +} + +/* + * Fill buffer in the non-interleaved mode. The order of samples is C0, ..., C0, C1, ..., C1, C2... + * The channel buffers lay in the DMA buffer continuously (see default copy + * handlers in the pcm_lib.c file). + * + * Here we increment the DMA buffer position every time we write a byte to any channel 'buffer'. + * We need this to simulate the correct hardware pointer moving. + */ +static void fill_block_pattern_n(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime) +{ + size_t i; + unsigned int channels = runtime->channels; + short ch_num; + + for (i = 0; i < v_iter->b_rw; i++) { + ch_num = i % channels; + runtime->dma_area[buf_pos_n(v_iter, channels, ch_num)] = + patt_bufs[ch_num].buf[(v_iter->total_bytes / channels) + % patt_bufs[ch_num].len]; + inc_buf_pos(v_iter, 1, runtime->dma_bytes); + } +} + +// Fill buffer in the interleaved mode. The order of samples is C0, C1, C2, C0, C1, C2, ... +static void fill_block_pattern_i(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime) +{ + size_t sample; + size_t pos_in_ch, pos_pattern; + short ch, pos_sample; + + pos_in_ch = ch_pos_i(v_iter->total_bytes, runtime->channels, v_iter->sample_bytes); + + for (sample = 0; sample < v_iter->s_rw_ch; sample++) { + for (ch = 0; ch < runtime->channels; ch++) { + for (pos_sample = 0; pos_sample < v_iter->sample_bytes; pos_sample++) { + pos_pattern = (pos_in_ch + sample * v_iter->sample_bytes + + pos_sample) % patt_bufs[ch].len; + runtime->dma_area[v_iter->buf_pos] = patt_bufs[ch].buf[pos_pattern]; + inc_buf_pos(v_iter, 1, runtime->dma_bytes); + } + } + } +} + +static void fill_block_pattern(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime) +{ + if (v_iter->interleaved) + fill_block_pattern_i(v_iter, runtime); + else + fill_block_pattern_n(v_iter, runtime); +} + +static void fill_block_rand_n(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime) +{ + unsigned int channels = runtime->channels; + // Remaining space in all channel buffers + size_t bytes_remain = runtime->dma_bytes - v_iter->buf_pos; + unsigned int i; + + for (i = 0; i < channels; i++) { + if (v_iter->b_rw <= bytes_remain) { + //b_rw - count of bytes must be written for all channels at each timer tick + get_random_bytes(runtime->dma_area + buf_pos_n(v_iter, channels, i), + v_iter->b_rw / channels); + } else { + // Write to the end of buffer and start from the beginning of it + get_random_bytes(runtime->dma_area + buf_pos_n(v_iter, channels, i), + bytes_remain / channels); + get_random_bytes(runtime->dma_area + v_iter->chan_block * i, + (v_iter->b_rw - bytes_remain) / channels); + } + } + inc_buf_pos(v_iter, v_iter->b_rw, runtime->dma_bytes); +} + +static void fill_block_rand_i(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime) +{ + size_t in_cur_block = runtime->dma_bytes - v_iter->buf_pos; + + if (v_iter->b_rw <= in_cur_block) { + get_random_bytes(&runtime->dma_area[v_iter->buf_pos], v_iter->b_rw); + } else { + get_random_bytes(&runtime->dma_area[v_iter->buf_pos], in_cur_block); + get_random_bytes(runtime->dma_area, v_iter->b_rw - in_cur_block); + } + inc_buf_pos(v_iter, v_iter->b_rw, runtime->dma_bytes); +} + +static void fill_block_random(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime) +{ + if (v_iter->interleaved) + fill_block_rand_i(v_iter, runtime); + else + fill_block_rand_n(v_iter, runtime); +} + +static void fill_block(struct pcmtst_buf_iter *v_iter, struct snd_pcm_runtime *runtime) +{ + switch (fill_mode) { + case FILL_MODE_RAND: + fill_block_random(v_iter, runtime); + break; + case FILL_MODE_PAT: + fill_block_pattern(v_iter, runtime); + break; + } +} + +/* + * Here we iterate through the buffer by (buffer_size / iterates_per_second) bytes. + * The driver uses timer to simulate the hardware pointer moving, and notify the PCM middle layer + * about period elapsed. + */ +static void timer_timeout(struct timer_list *data) +{ + struct pcmtst_buf_iter *v_iter; + struct snd_pcm_substream *substream; + + v_iter = from_timer(v_iter, data, timer_instance); + substream = v_iter->substream; + + if (v_iter->suspend) + return; + + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK && !v_iter->is_buf_corrupted) + check_buf_block(v_iter, substream->runtime); + else if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) + fill_block(v_iter, substream->runtime); + else + inc_buf_pos(v_iter, v_iter->b_rw, substream->runtime->dma_bytes); + + v_iter->period_pos += v_iter->b_rw; + if (v_iter->period_pos >= v_iter->period_bytes) { + v_iter->period_pos %= v_iter->period_bytes; + snd_pcm_period_elapsed(substream); + } + + if (!v_iter->suspend) + mod_timer(&v_iter->timer_instance, jiffies + TIMER_INTERVAL + inject_delay); +} + +static int snd_pcmtst_pcm_open(struct snd_pcm_substream *substream) +{ + struct snd_pcm_runtime *runtime = substream->runtime; + struct pcmtst_buf_iter *v_iter; + + if (inject_open_err) + return -EBUSY; + + v_iter = kzalloc(sizeof(*v_iter), GFP_KERNEL); + if (!v_iter) + return -ENOMEM; + + v_iter->substream = substream; + runtime->hw = snd_pcmtst_hw; + runtime->private_data = v_iter; + + playback_capture_test = 0; + ioctl_reset_test = 0; + + timer_setup(&v_iter->timer_instance, timer_timeout, 0); + + return 0; +} + +static int snd_pcmtst_pcm_close(struct snd_pcm_substream *substream) +{ + struct pcmtst_buf_iter *v_iter = substream->runtime->private_data; + + timer_shutdown_sync(&v_iter->timer_instance); + playback_capture_test = !v_iter->is_buf_corrupted; + kfree(v_iter); + return 0; +} + +static inline void reset_buf_iterator(struct pcmtst_buf_iter *v_iter) +{ + v_iter->buf_pos = 0; + v_iter->is_buf_corrupted = false; + v_iter->period_pos = 0; + v_iter->total_bytes = 0; +} + +static inline void start_pcmtest_timer(struct pcmtst_buf_iter *v_iter) +{ + v_iter->suspend = false; + mod_timer(&v_iter->timer_instance, jiffies + TIMER_INTERVAL); +} + +static int snd_pcmtst_pcm_trigger(struct snd_pcm_substream *substream, int cmd) +{ + struct pcmtst_buf_iter *v_iter = substream->runtime->private_data; + + if (inject_trigger_err) + return -EINVAL; + switch (cmd) { + case SNDRV_PCM_TRIGGER_START: + reset_buf_iterator(v_iter); + start_pcmtest_timer(v_iter); + break; + case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: + start_pcmtest_timer(v_iter); + break; + case SNDRV_PCM_TRIGGER_STOP: + case SNDRV_PCM_TRIGGER_PAUSE_PUSH: + // We can't call timer_shutdown_sync here, as it is forbidden to sleep here + v_iter->suspend = true; + timer_delete(&v_iter->timer_instance); + break; + } + + return 0; +} + +static snd_pcm_uframes_t snd_pcmtst_pcm_pointer(struct snd_pcm_substream *substream) +{ + struct pcmtst_buf_iter *v_iter = substream->runtime->private_data; + + return bytes_to_frames(substream->runtime, v_iter->buf_pos); +} + +static int snd_pcmtst_free(struct pcmtst *pcmtst) +{ + if (!pcmtst) + return 0; + kfree(pcmtst); + return 0; +} + +// These callbacks are required, but empty - all freeing occurs in pdev_remove +static int snd_pcmtst_dev_free(struct snd_device *device) +{ + return 0; +} + +static void pcmtst_pdev_release(struct device *dev) +{ +} + +static int snd_pcmtst_pcm_prepare(struct snd_pcm_substream *substream) +{ + struct snd_pcm_runtime *runtime = substream->runtime; + struct pcmtst_buf_iter *v_iter = runtime->private_data; + + if (inject_prepare_err) + return -EINVAL; + + v_iter->sample_bytes = samples_to_bytes(runtime, 1); + v_iter->period_bytes = snd_pcm_lib_period_bytes(substream); + v_iter->interleaved = true; + if (runtime->access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED || + runtime->access == SNDRV_PCM_ACCESS_MMAP_NONINTERLEAVED) { + v_iter->chan_block = snd_pcm_lib_buffer_bytes(substream) / runtime->channels; + v_iter->interleaved = false; + } + // We want to record RATE * ch_cnt samples per sec, it is rate * sample_bytes * ch_cnt bytes + v_iter->s_rw_ch = runtime->rate / TIMER_PER_SEC; + v_iter->b_rw = v_iter->s_rw_ch * v_iter->sample_bytes * runtime->channels; + + return 0; +} + +static int snd_pcmtst_pcm_hw_params(struct snd_pcm_substream *substream, + struct snd_pcm_hw_params *params) +{ + if (inject_hwpars_err) + return -EBUSY; + return 0; +} + +static int snd_pcmtst_pcm_hw_free(struct snd_pcm_substream *substream) +{ + return 0; +} + +static int snd_pcmtst_ioctl(struct snd_pcm_substream *substream, unsigned int cmd, void *arg) +{ + switch (cmd) { + case SNDRV_PCM_IOCTL1_RESET: + ioctl_reset_test = 1; + break; + } + return snd_pcm_lib_ioctl(substream, cmd, arg); +} + +static int snd_pcmtst_sync_stop(struct snd_pcm_substream *substream) +{ + struct pcmtst_buf_iter *v_iter = substream->runtime->private_data; + + timer_delete_sync(&v_iter->timer_instance); + + return 0; +} + +static const struct snd_pcm_ops snd_pcmtst_playback_ops = { + .open = snd_pcmtst_pcm_open, + .close = snd_pcmtst_pcm_close, + .trigger = snd_pcmtst_pcm_trigger, + .hw_params = snd_pcmtst_pcm_hw_params, + .ioctl = snd_pcmtst_ioctl, + .sync_stop = snd_pcmtst_sync_stop, + .hw_free = snd_pcmtst_pcm_hw_free, + .prepare = snd_pcmtst_pcm_prepare, + .pointer = snd_pcmtst_pcm_pointer, +}; + +static const struct snd_pcm_ops snd_pcmtst_capture_ops = { + .open = snd_pcmtst_pcm_open, + .close = snd_pcmtst_pcm_close, + .trigger = snd_pcmtst_pcm_trigger, + .hw_params = snd_pcmtst_pcm_hw_params, + .hw_free = snd_pcmtst_pcm_hw_free, + .ioctl = snd_pcmtst_ioctl, + .sync_stop = snd_pcmtst_sync_stop, + .prepare = snd_pcmtst_pcm_prepare, + .pointer = snd_pcmtst_pcm_pointer, +}; + +static int snd_pcmtst_new_pcm(struct pcmtst *pcmtst) +{ + struct snd_pcm *pcm; + int err; + + err = snd_pcm_new(pcmtst->card, "PCMTest", 0, PLAYBACK_SUBSTREAM_CNT, + CAPTURE_SUBSTREAM_CNT, &pcm); + if (err < 0) + return err; + pcm->private_data = pcmtst; + strcpy(pcm->name, "PCMTest"); + pcmtst->pcm = pcm; + snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &snd_pcmtst_playback_ops); + snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_pcmtst_capture_ops); + + err = snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV, &pcmtst->pdev->dev, + 0, 128 * 1024); + return err; +} + +static int snd_pcmtst_create(struct snd_card *card, struct platform_device *pdev, + struct pcmtst **r_pcmtst) +{ + struct pcmtst *pcmtst; + int err; + static const struct snd_device_ops ops = { + .dev_free = snd_pcmtst_dev_free, + }; + + pcmtst = kzalloc(sizeof(*pcmtst), GFP_KERNEL); + if (!pcmtst) + return -ENOMEM; + pcmtst->card = card; + pcmtst->pdev = pdev; + + err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, pcmtst, &ops); + if (err < 0) + goto _err_free_chip; + + err = snd_pcmtst_new_pcm(pcmtst); + if (err < 0) + goto _err_free_chip; + + *r_pcmtst = pcmtst; + return 0; + +_err_free_chip: + snd_pcmtst_free(pcmtst); + return err; +} + +static int pcmtst_probe(struct platform_device *pdev) +{ + struct snd_card *card; + struct pcmtst *pcmtst; + int err; + + err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); + if (err) + return err; + + err = snd_devm_card_new(&pdev->dev, index, id, THIS_MODULE, 0, &card); + if (err < 0) + return err; + err = snd_pcmtst_create(card, pdev, &pcmtst); + if (err < 0) + return err; + + strcpy(card->driver, "PCM-TEST Driver"); + strcpy(card->shortname, "PCM-Test"); + strcpy(card->longname, "PCM-Test virtual driver"); + + err = snd_card_register(card); + if (err < 0) + return err; + + platform_set_drvdata(pdev, pcmtst); + + return 0; +} + +static void pdev_remove(struct platform_device *pdev) +{ + struct pcmtst *pcmtst = platform_get_drvdata(pdev); + + snd_pcmtst_free(pcmtst); +} + +static struct platform_device pcmtst_pdev = { + .name = "pcmtest", + .dev.release = pcmtst_pdev_release, +}; + +static struct platform_driver pcmtst_pdrv = { + .probe = pcmtst_probe, + .remove_new = pdev_remove, + .driver = { + .name = "pcmtest", + }, +}; + +static ssize_t pattern_write(struct file *file, const char __user *u_buff, size_t len, loff_t *off) +{ + struct pattern_buf *patt_buf = file->f_inode->i_private; + ssize_t to_write = len; + + if (*off + to_write > MAX_PATTERN_LEN) + to_write = MAX_PATTERN_LEN - *off; + + // Crop silently everything over the buffer + if (to_write <= 0) + return len; + + if (copy_from_user(patt_buf->buf + *off, u_buff, to_write)) + return -EFAULT; + + patt_buf->len = *off + to_write; + *off += to_write; + + return to_write; +} + +static ssize_t pattern_read(struct file *file, char __user *u_buff, size_t len, loff_t *off) +{ + struct pattern_buf *patt_buf = file->f_inode->i_private; + ssize_t to_read = len; + + if (*off + to_read >= MAX_PATTERN_LEN) + to_read = MAX_PATTERN_LEN - *off; + if (to_read <= 0) + return 0; + + if (copy_to_user(u_buff, patt_buf->buf + *off, to_read)) + to_read = 0; + else + *off += to_read; + + return to_read; +} + +static const struct file_operations fill_pattern_fops = { + .read = pattern_read, + .write = pattern_write, +}; + +static int setup_patt_bufs(void) +{ + size_t i; + + for (i = 0; i < ARRAY_SIZE(patt_bufs); i++) { + patt_bufs[i].buf = kzalloc(MAX_PATTERN_LEN, GFP_KERNEL); + if (!patt_bufs[i].buf) + break; + strcpy(patt_bufs[i].buf, DEFAULT_PATTERN); + patt_bufs[i].len = DEFAULT_PATTERN_LEN; + } + + return i; +} + +static const char * const pattern_files[] = { "fill_pattern0", "fill_pattern1", + "fill_pattern2", "fill_pattern3"}; +static int init_debug_files(int buf_count) +{ + size_t i; + char len_file_name[32]; + + driver_debug_dir = debugfs_create_dir("pcmtest", NULL); + if (IS_ERR(driver_debug_dir)) + return PTR_ERR(driver_debug_dir); + debugfs_create_u8("pc_test", 0444, driver_debug_dir, &playback_capture_test); + debugfs_create_u8("ioctl_test", 0444, driver_debug_dir, &ioctl_reset_test); + + for (i = 0; i < buf_count; i++) { + debugfs_create_file(pattern_files[i], 0600, driver_debug_dir, + &patt_bufs[i], &fill_pattern_fops); + snprintf(len_file_name, sizeof(len_file_name), "%s_len", pattern_files[i]); + debugfs_create_u32(len_file_name, 0444, driver_debug_dir, &patt_bufs[i].len); + } + + return 0; +} + +static void free_pattern_buffers(void) +{ + int i; + + for (i = 0; i < buf_allocated; i++) + kfree(patt_bufs[i].buf); +} + +static void clear_debug_files(void) +{ + debugfs_remove_recursive(driver_debug_dir); +} + +static int __init mod_init(void) +{ + int err = 0; + + buf_allocated = setup_patt_bufs(); + if (!buf_allocated) + return -ENOMEM; + + snd_pcmtst_hw.channels_max = buf_allocated; + + err = init_debug_files(buf_allocated); + if (err) + return err; + err = platform_device_register(&pcmtst_pdev); + if (err) + return err; + err = platform_driver_register(&pcmtst_pdrv); + if (err) + platform_device_unregister(&pcmtst_pdev); + return err; +} + +static void __exit mod_exit(void) +{ + clear_debug_files(); + free_pattern_buffers(); + + platform_driver_unregister(&pcmtst_pdrv); + platform_device_unregister(&pcmtst_pdev); +} + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Ivan Orlov"); +module_init(mod_init); +module_exit(mod_exit); |