Documentation/locking/00-INDEX


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00-INDEX
	- this file.
lockdep-design.txt
	- documentation on the runtime locking correctness validator.
lockstat.txt
	- info on collecting statistics on locks (and contention).
mutex-design.txt
	- info on the generic mutex subsystem.
rt-mutex-design.txt
	- description of the RealTime mutex implementation design.
rt-mutex.txt
	- desc. of RT-mutex subsystem with PI (Priority Inheritance) support.
spinlocks.txt
	- info on using spinlocks to provide exclusive access in kernel.
ww-mutex-design.txt
	- Intro to Mutex wait/would deadlock handling.s
/* Atmel PDMIC driver
 *
 * Copyright (C) 2015 Atmel
 *
 * Author: Songjun Wu <songjun.wu@atmel.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 or later
 * as published by the Free Software Foundation.
 */

#include <linux/of.h>
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <sound/core.h>
#include <sound/dmaengine_pcm.h>
#include <sound/pcm_params.h>
#include <sound/tlv.h>
#include "atmel-pdmic.h"

struct atmel_pdmic_pdata {
	u32 mic_min_freq;
	u32 mic_max_freq;
	s32 mic_offset;
	const char *card_name;
};

struct atmel_pdmic {
	dma_addr_t phy_base;
	struct regmap *regmap;
	struct clk *pclk;
	struct clk *gclk;
	struct device *dev;
	int irq;
	struct snd_pcm_substream *substream;
	const struct atmel_pdmic_pdata *pdata;
};

static const struct of_device_id atmel_pdmic_of_match[] = {
	{
		.compatible = "atmel,sama5d2-pdmic",
	}, {
		/* sentinel */
	}
};
MODULE_DEVICE_TABLE(of, atmel_pdmic_of_match);

#define PDMIC_OFFSET_MAX_VAL	S16_MAX
#define PDMIC_OFFSET_MIN_VAL	S16_MIN

static struct atmel_pdmic_pdata *atmel_pdmic_dt_init(struct device *dev)
{
	struct device_node *np = dev->of_node;
	struct atmel_pdmic_pdata *pdata;

	if (!np) {
		dev_err(dev, "device node not found\n");
		return ERR_PTR(-EINVAL);
	}

	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
	if (!pdata)
		return ERR_PTR(-ENOMEM);

	if (of_property_read_string(np, "atmel,model", &pdata->card_name))
		pdata->card_name = "PDMIC";

	if (of_property_read_u32(np, "atmel,mic-min-freq",
				 &pdata->mic_min_freq)) {
		dev_err(dev, "failed to get mic-min-freq\n");
		return ERR_PTR(-EINVAL);
	}

	if (of_property_read_u32(np, "atmel,mic-max-freq",
				 &pdata->mic_max_freq)) {
		dev_err(dev, "failed to get mic-max-freq\n");
		return ERR_PTR(-EINVAL);
	}

	if (pdata->mic_max_freq < pdata->mic_min_freq) {
		dev_err(dev,
			"mic-max-freq should not be less than mic-min-freq\n");
		return ERR_PTR(-EINVAL);
	}

	if (of_property_read_s32(np, "atmel,mic-offset", &pdata->mic_offset))
		pdata->mic_offset = 0;

	if (pdata->mic_offset > PDMIC_OFFSET_MAX_VAL) {
		dev_warn(dev,
			 "mic-offset value %d is larger than the max value %d, the max value is specified\n",
			 pdata->mic_offset, PDMIC_OFFSET_MAX_VAL);
		pdata->mic_offset = PDMIC_OFFSET_MAX_VAL;
	} else if (pdata->mic_offset < PDMIC_OFFSET_MIN_VAL) {
		dev_warn(dev,
			 "mic-offset value %d is less than the min value %d, the min value is specified\n",
			 pdata->mic_offset, PDMIC_OFFSET_MIN_VAL);
		pdata->mic_offset = PDMIC_OFFSET_MIN_VAL;
	}

	return pdata;
}

/* cpu dai component */
static int atmel_pdmic_cpu_dai_startup(struct snd_pcm_substream *substream,
					struct snd_soc_dai *cpu_dai)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct atmel_pdmic *dd = snd_soc_card_get_drvdata(rtd->card);
	int ret;

	ret = clk_prepare_enable(dd->gclk);
	if (ret)
		return ret;

	ret =  clk_prepare_enable(dd->pclk);
	if (ret) {
		clk_disable_unprepare(dd->gclk);
		return ret;
	}

	/* Clear all bits in the Control Register(PDMIC_CR) */
	regmap_write(dd->regmap, PDMIC_CR, 0);

	dd->substream = substream;

	/* Enable the overrun error interrupt */
	regmap_write(dd->regmap, PDMIC_IER, PDMIC_IER_OVRE);

	return 0;
}

static void atmel_pdmic_cpu_dai_shutdown(struct snd_pcm_substream *substream,
					struct snd_soc_dai *cpu_dai)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct atmel_pdmic *dd = snd_soc_card_get_drvdata(rtd->card);

	/* Disable the overrun error interrupt */
	regmap_write(dd->regmap, PDMIC_IDR, PDMIC_IDR_OVRE);

	clk_disable_unprepare(dd->gclk);
	clk_disable_unprepare(dd->pclk);
}

static int atmel_pdmic_cpu_dai_prepare(struct snd_pcm_substream *substream,
					struct snd_soc_dai *cpu_dai)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct atmel_pdmic *dd = snd_soc_card_get_drvdata(rtd->card);
	u32 val;

	/* Clean the PDMIC Converted Data Register */
	return regmap_read(dd->regmap, PDMIC_CDR, &val);
}

static const struct snd_soc_dai_ops atmel_pdmic_cpu_dai_ops = {
	.startup	= atmel_pdmic_cpu_dai_startup,
	.shutdown	= atmel_pdmic_cpu_dai_shutdown,
	.prepare	= atmel_pdmic_cpu_dai_prepare,
};

#define ATMEL_PDMIC_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S32_LE)

static struct snd_soc_dai_driver atmel_pdmic_cpu_dai = {
	.capture = {
		.channels_min	= 1,
		.channels_max	= 1,
		.rates		= SNDRV_PCM_RATE_KNOT,
		.formats	= ATMEL_PDMIC_FORMATS,},
	.ops = &atmel_pdmic_cpu_dai_ops,
};

static const struct snd_soc_component_driver atmel_pdmic_cpu_dai_component = {
	.name = "atmel-pdmic",
};

/* platform */
#define ATMEL_PDMIC_MAX_BUF_SIZE  (64 * 1024)
#define ATMEL_PDMIC_PREALLOC_BUF_SIZE  ATMEL_PDMIC_MAX_BUF_SIZE

static const struct snd_pcm_hardware atmel_pdmic_hw = {
	.info			= SNDRV_PCM_INFO_MMAP
				| SNDRV_PCM_INFO_MMAP_VALID
				| SNDRV_PCM_INFO_INTERLEAVED
				| SNDRV_PCM_INFO_RESUME
				| SNDRV_PCM_INFO_PAUSE,
	.formats		= ATMEL_PDMIC_FORMATS,
	.buffer_bytes_max	= ATMEL_PDMIC_MAX_BUF_SIZE,
	.period_bytes_min	= 256,
	.period_bytes_max	= 32 * 1024,
	.periods_min		= 2,
	.periods_max		= 256,
};

static int
atmel_pdmic_platform_configure_dma(struct snd_pcm_substream *substream,
				struct snd_pcm_hw_params *params,
				struct dma_slave_config *slave_config)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct atmel_pdmic *dd = snd_soc_card_get_drvdata(rtd->card);
	int ret;

	ret = snd_hwparams_to_dma_slave_config(substream, params,
					       slave_config);
	if (ret) {
		dev_err(dd->dev,
			"hw params to dma slave configure failed\n");
		return ret;
	}

	slave_config->src_addr		= dd->phy_base + PDMIC_CDR;
	slave_config->src_maxburst	= 1;
	slave_config->dst_maxburst	= 1;

	return 0;
}

static const struct snd_dmaengine_pcm_config
atmel_pdmic_dmaengine_pcm_config = {
	.prepare_slave_config	= atmel_pdmic_platform_configure_dma,
	.pcm_hardware		= &atmel_pdmic_hw,
	.prealloc_buffer_size	= ATMEL_PDMIC_PREALLOC_BUF_SIZE,
};

/* codec */
/* Mic Gain = dgain * 2^(-scale) */
struct mic_gain {
	unsigned int dgain;
	unsigned int scale;
};

/* range from -90 dB to 90 dB */
static const struct mic_gain mic_gain_table[] = {
{    1, 15}, {    1, 14},                           /* -90, -84 dB */
{    3, 15}, {    1, 13}, {    3, 14}, {    1, 12}, /* -81, -78, -75, -72 dB */
{    5, 14}, {   13, 15},                           /* -70, -68 dB */
{    9, 14}, {   21, 15}, {   23, 15}, {   13, 14}, /* -65 ~ -62 dB */
{   29, 15}, {   33, 15}, {   37, 15}, {   41, 15}, /* -61 ~ -58 dB */
{   23, 14}, {   13, 13}, {   58, 15}, {   65, 15}, /* -57 ~ -54 dB */
{   73, 15}, {   41, 14}, {   23, 13}, {   13, 12}, /* -53 ~ -50 dB */
{   29, 13}, {   65, 14}, {   73, 14}, {   41, 13}, /* -49 ~ -46 dB */
{   23, 12}, {  207, 15}, {   29, 12}, {   65, 13}, /* -45 ~ -42 dB */
{   73, 13}, {   41, 12}, {   23, 11}, {  413, 15}, /* -41 ~ -38 dB */
{  463, 15}, {  519, 15}, {  583, 15}, {  327, 14}, /* -37 ~ -34 dB */
{  367, 14}, {  823, 15}, {  231, 13}, { 1036, 15}, /* -33 ~ -30 dB */
{ 1163, 15}, { 1305, 15}, {  183, 12}, { 1642, 15}, /* -29 ~ -26 dB */
{ 1843, 15}, { 2068, 15}, {  145, 11}, { 2603, 15}, /* -25 ~ -22 dB */
{  365, 12}, { 3277, 15}, { 3677, 15}, { 4125, 15}, /* -21 ~ -18 dB */
{ 4629, 15}, { 5193, 15}, { 5827, 15}, { 3269, 14}, /* -17 ~ -14 dB */
{  917, 12}, { 8231, 15}, { 9235, 15}, { 5181, 14}, /* -13 ~ -10 dB */
{11627, 15}, {13045, 15}, {14637, 15}, {16423, 15}, /*  -9 ~ -6 dB */
{18427, 15}, {20675, 15}, { 5799, 13}, {26029, 15}, /*  -5 ~ -2 dB */
{ 7301, 13}, {    1,  0}, {18383, 14}, {10313, 13}, /*  -1 ~ 2 dB */
{23143, 14}, {25967, 14}, {29135, 14}, {16345, 13}, /*   3 ~ 6 dB */
{ 4585, 11}, {20577, 13}, { 1443,  9}, {25905, 13}, /*   7 ~ 10 dB */
{14533, 12}, { 8153, 11}, { 2287,  9}, {20529, 12}, /*  11 ~ 14 dB */
{11517, 11}, { 6461, 10}, {28997, 12}, { 4067,  9}, /*  15 ~ 18 dB */
{18253, 11}, {   10,  0}, {22979, 11}, {25783, 11}, /*  19 ~ 22 dB */
{28929, 11}, {32459, 11}, { 9105,  9}, {20431, 10}, /*  23 ~ 26 dB */
{22925, 10}, {12861,  9}, { 7215,  8}, {16191,  9}, /*  27 ~ 30 dB */
{ 9083,