/*
 * bf5xx-ac97.c -- AC97 support for the ADI blackfin chip.
 *
 * Author:	Roy Huang
 * Created:	11th. June 2007
 * Copyright:	Analog Device Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/wait.h>
#include <linux/delay.h>
#include <linux/slab.h>

#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/ac97_codec.h>
#include <sound/initval.h>
#include <sound/soc.h>

#include <asm/irq.h>
#include <asm/portmux.h>
#include <linux/mutex.h>
#include <linux/gpio.h>

#include "bf5xx-sport.h"
#include "bf5xx-ac97.h"

/* Anomaly notes:
 *  05000250 -	AD1980 is running in TDM mode and RFS/TFS are generated by SPORT
 *		contrtoller. But, RFSDIV and TFSDIV are always set to 16*16-1,
 *		while the max AC97 data size is 13*16. The DIV is always larger
 *		than data size. AD73311 and ad2602 are not running in TDM mode.
 *		AD1836 and AD73322 depend on external RFS/TFS only. So, this
 *		anomaly does not affect blackfin sound drivers.
*/

static struct sport_device *ac97_sport_handle;

void bf5xx_pcm_to_ac97(struct ac97_frame *dst, const __u16 *src,
		size_t count, unsigned int chan_mask)
{
	while (count--) {
		dst->ac97_tag = TAG_VALID;
		if (chan_mask & SP_FL) {
			dst->ac97_pcm_r = *src++;
			dst->ac97_tag |= TAG_PCM_RIGHT;
		}
		if (chan_mask & SP_FR) {
			dst->ac97_pcm_l = *src++;
			dst->ac97_tag |= TAG_PCM_LEFT;

		}
#if defined(CONFIG_SND_BF5XX_MULTICHAN_SUPPORT)
		if (chan_mask & SP_SR) {
			dst->ac97_sl = *src++;
			dst->ac97_tag |= TAG_PCM_SL;
		}
		if (chan_mask & SP_SL) {
			dst->ac97_sr = *src++;
			dst->ac97_tag |= TAG_PCM_SR;
		}
		if (chan_mask & SP_LFE) {
			dst->ac97_lfe = *src++;
			dst->ac97_tag |= TAG_PCM_LFE;
		}
		if (chan_mask & SP_FC) {
			dst->ac97_center = *src++;
			dst->ac97_tag |= TAG_PCM_CENTER;
		}
#endif
		dst++;
	}
}
EXPORT_SYMBOL(bf5xx_pcm_to_ac97);

void bf5xx_ac97_to_pcm(const struct ac97_frame *src, __u16 *dst,
		size_t count)
{
	while (count--) {
		*(dst++) = src->ac97_pcm_l;
		*(dst++) = src->ac97_pcm_r;
		src++;
	}
}
EXPORT_SYMBOL(bf5xx_ac97_to_pcm);

static unsigned int sport_tx_curr_frag(struct sport_device *sport)
{
	return sport->tx_curr_frag = sport_curr_offset_tx(sport) /
			sport->tx_fragsize;
}

static void enqueue_cmd(struct snd_ac97 *ac97, __u16 addr, __u16 data)
{
	struct sport_device *sport = ac97_sport_handle;
	int *cmd_count = sport->private_data;
	int nextfrag = sport_tx_curr_frag(sport);
	struct ac97_frame *nextwrite;

	sport_incfrag(sport, &nextfrag, 1);

	nextwrite = (struct ac97_frame *)(sport->tx_buf +
			nextfrag * sport->tx_fragsize);
	pr_debug("sport->tx_buf:%p, nextfrag:0x%x nextwrite:%p, cmd_count:%d\n",
		sport->tx_buf, nextfrag, nextwrite, cmd_count[nextfrag]);
	nextwrite[cmd_count[nextfrag]].ac97_tag |= TAG_CMD;
	nextwrite[cmd_count[nextfrag]].ac97_addr = addr;
	nextwrite[cmd_count[nextfrag]].ac97_data = data;
	++cmd_count[nextfrag];
	pr_debug("ac97_sport: Inserting %02x/%04x into fragment %d\n",
			addr >> 8, data, nextfrag);
}

static unsigned short bf5xx_ac97_read(struct snd_ac97 *ac97,
	unsigned short reg)
{
	struct sport_device *sport_handle = ac97_sport_handle;
	struct ac97_frame out_frame[2], in_frame[2];

	pr_debug("%s enter 0x%x\n", __func__, reg);

	/* When dma descriptor is enabled, the register should not be read */
	if (sport_handle->tx_run || sport_handle->rx_run) {
		pr_err("Could you send a mail to cliff.cai@analog.com "
				"to report this?\n");
		return -EFAULT;
	}

	memset(&out_frame, 0, 2 * sizeof(struct ac97_frame));
	memset(&in_frame, 0, 2 * sizeof(struct ac97_frame));
	out_frame[0].ac97_tag = TAG_VALID | TAG_CMD;
	out_frame[0].ac97_addr = ((reg << 8) | 0x8000);
	sport_send_and_recv(sport_handle, (unsigned char *)&out_frame,
			(unsigned char *)&in_frame,
			2 * sizeof(struct ac97_frame));
	return in_frame[1].ac97_data;
}

void bf5xx_ac97_write(struct snd_ac97 *ac97, unsigned short reg,
	unsigned short val)
{
	struct sport_device *sport_handle = ac97_sport_handle;

	pr_debug("%s enter 0x%x:0x%04x\n", __func__, reg, val);

	if (sport_handle->tx_run) {
		enqueue_cmd(ac97, (reg << 8), val); /* write */
		enqueue_cmd(ac97, (reg << 8) | 0x8000, 0); /* read back */
	} else {
		struct ac97_frame frame;
		memset(&frame, 0, sizeof(struct ac97_frame));
		frame.ac97_tag = TAG_VALID | TAG_CMD;
		frame.ac97_addr = (reg << 8);
		frame.ac97_data = val;
		sport_send_and_recv(sport_handle, (unsigned char *)&frame, \
				NULL, sizeof(struct ac97_frame));
	}
}

static void bf5xx_ac97_warm_reset(struct snd_ac97 *ac97)
{
	struct sport_device *sport_handle = ac97_sport_handle;
	u16 gpio = P_IDENT(sport_handle->pin_req[3]);

	pr_debug("%s enter\n", __func__);

	peripheral_free_list(sport_handle->pin_req);
	gpio_request(gpio, "bf5xx-ac97");
	gpio_direction_output(gpio, 1);
	udelay(2);
	gpio_set_value(gpio, 0);
	udelay(1);
	gpio_free(gpio);
	peripheral_request_list(sport_handle->pin_req, "soc-audio");
}

static void bf5xx_ac97_cold_reset(struct snd_ac97 *ac97)
{
#ifdef CONFIG_SND_BF5XX_HAVE_COLD_RESET
	pr_debug("%s enter\n", __func__);

	/* It is specified for bf548-ezkit */
	gpio_set_value(CONFIG_SND_BF5XX_RESET_GPIO_NUM, 0);
	/* Keep reset pin low for 1 ms */
	mdelay(1);
	gpio_set_value(CONFIG_SND_BF5XX_RESET_GPIO_NUM, 1);
	/* Wait for bit clock recover */
	mdelay(1);
#else
	pr_info("%s: Not implemented\n", __func__);
#endif
}

struct snd_ac97_bus_ops soc_ac97_ops = {
	.read	= bf5xx_ac97_read,
	.write	= bf5xx_ac97_write,
	.warm_reset	= bf5xx_ac97_warm_reset,
	.reset	= bf5xx_ac97_cold_reset,
};
EXPORT_SYMBOL_GPL(soc_ac97_ops);

#ifdef CONFIG_PM
static int bf5xx_ac97_suspend(struct snd_soc_dai *dai)
{
	struct sport_device *sport = snd_soc_dai_get_drvdata(dai);

	pr_debug("%s : sport %d\n", __func__, dai->id);
	if (!dai->active)
		return 0;
	if (dai->capture_active)
		sport_rx_stop(sport);
	if (dai->playback_active)
		sport_tx_stop(sport);
	return 0;
}

static int bf5xx_ac97_resume(struct snd_soc_dai *dai)
{
	int ret;
	struct sport_device *sport = snd_soc_dai_get_drvdata(dai);

	pr_debug("%s : sport %d\n", __func__, dai->id);
	if (!dai->active)
		return 0;

#if defined(CONFIG_SND_BF5XX_MULTICHAN_SUPPORT)
	ret = sport_set_multichannel(sport, 16, 0x3FF, 1);
#else
	ret = sport_set_multichannel(sport, 16, 0x1F, 1);
#endif
	if (ret) {
		pr_err("SPORT is busy!\n");
		return -EBUSY;
	}

	ret = sport_config_rx(sport, IRFS, 0xF, 0, (16*16-1));
	if (ret) {
		pr_err("SPORT is busy!\n");
		return -EBUSY;
	}

	ret = sport_config_tx(sport, ITFS, 0xF, 0, (16*16-1));
	if (ret) {
		pr_err("SPORT is busy!\n");
		return -EBUSY;
	}

	return 0;
}

#else
#define bf5xx_ac97_suspend	NULL
#define bf5xx_ac97_resume	NULL
#endif

static struct snd_soc_dai_driver bfin_ac97_dai = {
	.ac97_control = 1,
	.suspend = bf5xx_ac97_suspend,
	.resume = bf5xx_ac97_resume,
	.playback = {
		.stream_name = "AC97 Playback",
		.channels_min = 2,
#if defined(CONFIG_SND_BF5XX_MULTICHAN_SUPPORT)
		.channels_max = 6,
#else
		.channels_max = 2,
#endif
		.rates = SNDRV_PCM_RATE_48000,
		.formats = SNDRV_PCM_FMTBIT_S16_LE, },
	.capture = {
		.stream_name = "AC97 Capture",
		.channels_min = 2,
		.channels_max = 2,
		.rates = SNDRV_PCM_RATE_48000,
		.formats = SNDRV_PCM_FMTBIT_S16_LE, },
};

static int __devinit asoc_bfin_ac97_probe(struct platform_device *pdev)
{
	struct sport_device *sport_handle;
	int ret;

#ifdef CONFIG_SND_BF5XX_HAVE_COLD_RESET
	/* Request PB3 as reset pin */
	if (gpio_request(CONFIG_SND_BF5XX_RESET_GPIO_NUM, "SND_AD198x RESET")) {
		pr_err("Failed to request GPIO_%d for reset\n",
				CONFIG_SND_BF5XX_RESET_GPIO_NUM);
		ret =  -1;
		goto gpio_err;
	}
	gpio_direction_output(CONFIG_SND_BF5XX_RESET_GPIO_NUM, 1);
#endif

	sport_handle = sport_init(pdev, 2, sizeof(struct ac97_frame),
		PAGE_SIZE);
	if (!sport_handle) {
		ret = -ENODEV;
		goto sport_err;
	}

	/*SPORT works in TDM mode to simulate AC97 transfers*/
#if defined(CONFIG_SND_BF5XX_MULTICHAN_SUPPORT)
	ret = sport_set_multichannel(sport_handle, 16, 0x3FF, 1);
#else
	ret = sport_set_multichannel(sport_handle, 16, 0x1F, 1);
#endif
	if (ret) {
		pr_err("SPORT is busy!\n");
		ret = -EBUSY;
		goto sport_config_err;
	}

	ret = sport_config_rx(sport_handle, IRFS, 0xF, 0, (16*16-1));
	if (ret) {
		pr_err("SPORT is busy!\n");
		ret = -EBUSY;
		goto sport_config_err;
	}

	ret = sport_config_tx(sport_handle, ITFS, 0xF, 0, (16*16-1));
	if (ret) {
		pr_err("SPORT is busy!\n");
		ret = -EBUSY;
		goto sport_config_err;
	}

	ret = snd_soc_register_dai(&pdev->dev, &bfin_ac97_dai);
	if (ret) {
		pr_err("Failed to register DAI: %d\n", ret);
		goto sport_config_err;
	}

	ac97_sport_handle = sport_handle;

	return 0;

sport_config_err:
	sport_done(sport_handle);
sport_err:
#ifdef CONFIG_SND_BF5XX_HAVE_COLD_RESET
	gpio_free(CONFIG_SND_BF5XX_RESET_GPIO_NUM);
gpio_err:
#endif

	return ret;
}

static int __devexit asoc_bfin_ac97_remove(struct platform_device *pdev)
{
	struct sport_device *sport_handle = platform_get_drvdata(pdev);

	snd_soc_unregister_dai(&pdev->dev);
	sport_done(sport_handle);
#ifdef CONFIG_SND_BF5XX_HAVE_COLD_RESET
	gpio_free(CONFIG_SND_BF5XX_RESET_GPIO_NUM);
#endif

	return 0;
}

static struct platform_driver asoc_bfin_ac97_driver = {
	.driver = {
			.name = "bfin-ac97",
			.owner = THIS_MODULE,
	},

	.probe = asoc_bfin_ac97_probe,
	.remove = __devexit_p(asoc_bfin_ac97_remove),
};

static int __init bfin_ac97_init(void)
{
	return platform_driver_register(&asoc_bfin_ac97_driver);
}
module_init(bfin_ac97_init);

static void __exit bfin_ac97_exit(void)
{
	platform_driver_unregister(&asoc_bfin_ac97_driver);
}
module_exit(bfin_ac97_exit);


MODULE_AUTHOR("Roy Huang");
MODULE_DESCRIPTION("AC97 driver for ADI Blackfin");
MODULE_LICENSE("GPL");