path: root/sound/soc/sti/uniperif_player.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) STMicroelectronics SA 2015
 * Authors: Arnaud Pouliquen <arnaud.pouliquen@st.com>
 *          for STMicroelectronics.
 */

#include <linux/clk.h>
#include <linux/mfd/syscon.h>

#include <sound/asoundef.h>
#include <sound/soc.h>

#include "uniperif.h"

/*
 * Some hardware-related definitions
 */

/* sys config registers definitions */
#define SYS_CFG_AUDIO_GLUE 0xA4

/*
 * Driver specific types.
 */

#define UNIPERIF_PLAYER_CLK_ADJ_MIN  -999999
#define UNIPERIF_PLAYER_CLK_ADJ_MAX  1000000
#define UNIPERIF_PLAYER_I2S_OUT 1 /* player id connected to I2S/TDM TX bus */

/*
 * Note: snd_pcm_hardware is linked to DMA controller but is declared here to
 * integrate  DAI_CPU capability in term of rate and supported channels
 */
static const struct snd_pcm_hardware uni_player_pcm_hw = {
	.info = SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
		SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_MMAP |
		SNDRV_PCM_INFO_MMAP_VALID,
	.formats = SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_S16_LE,

	.rates = SNDRV_PCM_RATE_CONTINUOUS,
	.rate_min = 8000,
	.rate_max = 192000,

	.channels_min = 2,
	.channels_max = 8,

	.periods_min = 2,
	.periods_max = 48,

	.period_bytes_min = 128,
	.period_bytes_max = 64 * PAGE_SIZE,
	.buffer_bytes_max = 256 * PAGE_SIZE
};

/*
 * uni_player_irq_handler
 * In case of error audio stream is stopped; stop action is protected via PCM
 * stream lock to avoid race condition with trigger callback.
 */
static irqreturn_t uni_player_irq_handler(int irq, void *dev_id)
{
	irqreturn_t ret = IRQ_NONE;
	struct uniperif *player = dev_id;
	unsigned int status;
	unsigned int tmp;

	spin_lock(&player->irq_lock);
	if (!player->substream)
		goto irq_spin_unlock;

	snd_pcm_stream_lock(player->substream);
	if (player->state == UNIPERIF_STATE_STOPPED)
		goto stream_unlock;

	/* Get interrupt status & clear them immediately */
	status = GET_UNIPERIF_ITS(player);
	SET_UNIPERIF_ITS_BCLR(player, status);

	/* Check for fifo error (underrun) */
	if (unlikely(status & UNIPERIF_ITS_FIFO_ERROR_MASK(player))) {
		dev_err(player->dev, "FIFO underflow error detected\n");

		/* Interrupt is just for information when underflow recovery */
		if (player->underflow_enabled) {
			/* Update state to underflow */
			player->state = UNIPERIF_STATE_UNDERFLOW;

		} else {
			/* Disable interrupt so doesn't continually fire */
			SET_UNIPERIF_ITM_BCLR_FIFO_ERROR(player);

			/* Stop the player */
			snd_pcm_stop_xrun(player->substream);
		}

		ret = IRQ_HANDLED;
	}

	/* Check for dma error (overrun) */
	if (unlikely(status & UNIPERIF_ITS_DMA_ERROR_MASK(player))) {
		dev_err(player->dev, "DMA error detected\n");

		/* Disable interrupt so doesn't continually fire */
		SET_UNIPERIF_ITM_BCLR_DMA_ERROR(player);

		/* Stop the player */
		snd_pcm_stop_xrun(player->substream);

		ret = IRQ_HANDLED;
	}

	/* Check for underflow recovery done */
	if (unlikely(status & UNIPERIF_ITM_UNDERFLOW_REC_DONE_MASK(player))) {
		if (!player->underflow_enabled) {
			dev_err(player->dev,
				"unexpected Underflow recovering\n");
			ret = -EPERM;
			goto stream_unlock;
		}
		/* Read the underflow recovery duration */
		tmp = GET_UNIPERIF_STATUS_1_UNDERFLOW_DURATION(player);
		dev_dbg(player->dev, "Underflow recovered (%d LR clocks max)\n",
			tmp);

		/* Clear the underflow recovery duration */
		SET_UNIPERIF_BIT_CONTROL_CLR_UNDERFLOW_DURATION(player);

		/* Update state to started */
		player->state = UNIPERIF_STATE_STARTED;

		ret = IRQ_HANDLED;
	}

	/* Check if underflow recovery failed */
	if (unlikely(status &
		     UNIPERIF_ITM_UNDERFLOW_REC_FAILED_MASK(player))) {
		dev_err(player->dev, "Underflow recovery failed\n");

		/* Stop the player */
		snd_pcm_stop_xrun(player->substream);

		ret = IRQ_HANDLED;
	}

stream_unlock:
	snd_pcm_stream_unlock(player->substream);
irq_spin_unlock:
	spin_unlock(&player->irq_lock);

	return ret;
}

static int uni_player_clk_set_rate(struct uniperif *player, unsigned long rate)
{
	int rate_adjusted, rate_achieved, delta, ret;
	int adjustment = player->clk_adj;

	/*
	 *             a
	 * F = f + --------- * f = f + d
	 *          1000000
	 *
	 *         a
	 * d = --------- * f
	 *      1000000
	 *
	 * where:
	 *   f - nominal rate
	 *   a - adjustment in ppm (parts per milion)
	 *   F - rate to be set in synthesizer
	 *   d - delta (difference) between f and F
	 */
	if (adjustment < 0) {
		/* div64_64 operates on unsigned values... */
		delta = -1;
		adjustment = -adjustment;
	} else {
		delta = 1;
	}
	/* 500000 ppm is 0.5, which is used to round up values */
	delta *= (int)div64_u64((uint64_t)rate *
				(uint64_t)adjustment + 500000, 1000000);
	rate_adjusted = rate + delta;

	/* Adjusted rate should never be == 0 */
	if (!rate_adjusted)
		return -