1 files changed, 602 insertions, 0 deletions

diff --git a/sound/atmel/abdac.c b/sound/atmel/abdac.c
new file mode 100644
index 0000000..28b3c7f
--- /dev/null
+++ b/sound/atmel/abdac.c
@@ -0,0 +1,602 @@
+/*
+ * Driver for the Atmel on-chip Audio Bitstream DAC (ABDAC)
+ *
+ * Copyright (C) 2006-2009 Atmel Corporation
+ *
+ * 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/clk.h>
+#include <linux/bitmap.h>
+#include <linux/dw_dmac.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+
+#include <sound/core.h>
+#include <sound/initval.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/atmel-abdac.h>
+
+/* DAC register offsets */
+#define DAC_DATA                                0x0000
+#define DAC_CTRL                                0x0008
+#define DAC_INT_MASK                            0x000c
+#define DAC_INT_EN                              0x0010
+#define DAC_INT_DIS                             0x0014
+#define DAC_INT_CLR                             0x0018
+#define DAC_INT_STATUS                          0x001c
+
+/* Bitfields in CTRL */
+#define DAC_SWAP_OFFSET                         30
+#define DAC_SWAP_SIZE                           1
+#define DAC_EN_OFFSET                           31
+#define DAC_EN_SIZE                             1
+
+/* Bitfields in INT_MASK/INT_EN/INT_DIS/INT_STATUS/INT_CLR */
+#define DAC_UNDERRUN_OFFSET                     28
+#define DAC_UNDERRUN_SIZE                       1
+#define DAC_TX_READY_OFFSET                     29
+#define DAC_TX_READY_SIZE                       1
+
+/* Bit manipulation macros */
+#define DAC_BIT(name)					\
+	(1 << DAC_##name##_OFFSET)
+#define DAC_BF(name, value)				\
+	(((value) & ((1 << DAC_##name##_SIZE) - 1))	\
+	 << DAC_##name##_OFFSET)
+#define DAC_BFEXT(name, value)				\
+	(((value) >> DAC_##name##_OFFSET)		\
+	 & ((1 << DAC_##name##_SIZE) - 1))
+#define DAC_BFINS(name, value, old)			\
+	(((old) & ~(((1 << DAC_##name##_SIZE) - 1)	\
+		    << DAC_##name##_OFFSET))		\
+	 | DAC_BF(name, value))
+
+/* Register access macros */
+#define dac_readl(port, reg)				\
+	__raw_readl((port)->regs + DAC_##reg)
+#define dac_writel(port, reg, value)			\
+	__raw_writel((value), (port)->regs + DAC_##reg)
+
+/*
+ * ABDAC supports a maximum of 6 different rates from a generic clock. The
+ * generic clock has a power of two divider, which gives 6 steps from 192 kHz
+ * to 5112 Hz.
+ */
+#define MAX_NUM_RATES	6
+/* ALSA seems to use rates between 192000 Hz and 5112 Hz. */
+#define RATE_MAX	192000
+#define RATE_MIN	5112
+
+enum {
+	DMA_READY = 0,
+};
+
+struct atmel_abdac_dma {
+	struct dma_chan		*chan;
+	struct dw_cyclic_desc	*cdesc;
+};
+
+struct atmel_abdac {
+	struct clk				*pclk;
+	struct clk				*sample_clk;
+	struct platform_device			*pdev;
+	struct atmel_abdac_dma			dma;
+
+	struct snd_pcm_hw_constraint_list	constraints_rates;
+	struct snd_pcm_substream		*substream;
+	struct snd_card				*card;
+	struct snd_pcm				*pcm;
+
+	void __iomem				*regs;
+	unsigned long				flags;
+	unsigned int				rates[MAX_NUM_RATES];
+	unsigned int				rates_num;
+	int					irq;
+};
+
+#define get_dac(card) ((struct atmel_abdac *)(card)->private_data)
+
+/* This function is called by the DMA driver. */
+static void atmel_abdac_dma_period_done(void *arg)
+{
+	struct atmel_abdac *dac = arg;
+	snd_pcm_period_elapsed(dac->substream);
+}
+
+static int atmel_abdac_prepare_dma(struct atmel_abdac *dac,
+		struct snd_pcm_substream *substream,
+		enum dma_data_direction direction)
+{
+	struct dma_chan			*chan = dac->dma.chan;
+	struct dw_cyclic_desc		*cdesc;
+	struct snd_pcm_runtime		*runtime = substream->runtime;
+	unsigned long			buffer_len, period_len;
+
+	/*
+	 * We don't do DMA on "complex" transfers, i.e. with
+	 * non-halfword-aligned buffers or lengths.
+	 */
+	if (runtime->dma_addr & 1 || runtime->buffer_size & 1) {
+		dev_dbg(&dac->pdev->dev, "too complex transfer\n");
+		return -EINVAL;
+	}
+
+	buffer_len = frames_to_bytes(runtime, runtime->buffer_size);
+	period_len = frames_to_bytes(runtime, runtime->period_size);
+
+	cdesc = dw_dma_cyclic_prep(chan, runtime->dma_addr, buffer_len,
+			period_len, DMA_TO_DEVICE);
+	if (IS_ERR(cdesc)) {
+		dev_dbg(&dac->pdev->dev, "could not prepare cyclic DMA\n");
+		return PTR_ERR(cdesc);
+	}
+
+	cdesc->period_callback = atmel_abdac_dma_period_done;
+	cdesc->period_callback_param = dac;
+
+	dac->dma.cdesc = cdesc;
+
+	set_bit(DMA_READY, &dac->flags);
+
+	return 0;
+}
+
+static struct snd_pcm_hardware atmel_abdac_hw = {
+	.info			= (SNDRV_PCM_INFO_MMAP
+				  | SNDRV_PCM_INFO_MMAP_VALID
+				  | SNDRV_PCM_INFO_INTERLEAVED
+				  | SNDRV_PCM_INFO_BLOCK_TRANSFER
+				  | SNDRV_PCM_INFO_RESUME
+				  | SNDRV_PCM_INFO_PAUSE),
+	.formats		= (SNDRV_PCM_FMTBIT_S16_BE),
+	.rates			= (SNDRV_PCM_RATE_KNOT),
+	.rate_min		= RATE_MIN,
+	.rate_max		= RATE_MAX,
+	.channels_min		= 2,
+	.channels_max		= 2,
+	.buffer_bytes_max	= 64 * 4096,
+	.period_bytes_min	= 4096,
+	.period_bytes_max	= 4096,
+	.periods_min		= 4,
+	.periods_max		= 64,
+};
+
+static int atmel_abdac_open(struct snd_pcm_substream *substream)
+{
+	struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
+
+	dac->substream = substream;
+	atmel_abdac_hw.rate_max = dac->rates[dac->rates_num - 1];
+	atmel_abdac_hw.rate_min = dac->rates[0];
+	substream->runtime->hw = atmel_abdac_hw;
+
+	return snd_pcm_hw_constraint_list(substream->runtime, 0,
+			SNDRV_PCM_HW_PARAM_RATE, &dac->constraints_rates);
+}
+
+static int atmel_abdac_close(struct snd_pcm_substream *substream)
+{
+	struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
+	dac->substream = NULL;
+	return 0;
+}
+
+static int atmel_abdac_hw_params(struct snd_pcm_substream *substream,
+		struct snd_pcm_hw_params *hw_params)
+{
+	struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
+	int retval;
+
+	retval = snd_pcm_lib_malloc_pages(substream,
+			params_buffer_bytes(hw_params));
+	if (retval < 0)
+		return retval;
+	/* snd_pcm_lib_malloc_pages returns 1 if buffer is changed. */
+	if (retval == 1)
+		if (test_and_clear_bit(DMA_READY, &dac->flags))
+			dw_dma_cyclic_free(dac->dma.chan);
+
+	return retval;
+}
+
+static int atmel_abdac_hw_free(struct snd_pcm_substream *substream)
+{
+	struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
+	if (test_and_clear_bit(DMA_READY, &dac->flags))
+		dw_dma_cyclic_free(dac->dma.chan);
+	return snd_pcm_lib_free_pages(substream);
+}
+
+static int atmel_abdac_prepare(struct snd_pcm_substream *substream)
+{
+	struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
+	int retval;
+
+	retval = clk_set_rate(dac->sample_clk, 256 * substream->runtime->rate);
+	if (retval)
+		return retval;
+
+	if (!test_bit(DMA_READY, &dac->flags))
+		retval = atmel_abdac_prepare_dma(dac, substream, DMA_TO_DEVICE);
+
+	return retval;
+}
+
+static int atmel_abdac_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct atmel_abdac *dac = snd_pcm_substream_chip(substream);
+	int retval = 0;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: /* fall through */
+	case SNDRV_PCM_TRIGGER_RESUME: /* fall through */
+	case SNDRV_PCM_TRIGGER_START:
+		clk_enable(dac->sample_clk);
+		retval = dw_dma_cyclic_start(dac->dma.chan);
+		if (retval)
+			goto out;
+		dac_writel(dac, CTRL, DAC_BIT(EN));
+		break;
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH: /* fall through */
+	case SNDRV_PCM_TRIGGER_SUSPEND: /* fall through */
+	case SNDRV_PCM_TRIGGER_STOP:
+		dw_dma_cyclic_stop(dac->dma.chan);
+		dac_writel(dac, DATA, 0);
+		dac_writel(dac, CTRL, 0);
+		clk_disable(dac->sample_clk);
+		break;
+	default:
+		retval = -EINVAL;
+		break;
+	}
+out:
+	return retval;
+}
+
+static snd_pcm_uframes_t
+atmel_abdac_pointer(struct snd_pcm_substream *substream)
+{
+	struct atmel_abdac	*dac = snd_pcm_substream_chip(substream);
+	struct snd_pcm_runtime	*runtime = substream->runtime;
+	snd_pcm_uframes_t	frames;
+	unsigned long		bytes;
+
+	bytes = dw_dma_get_src_addr(dac->dma.chan);
+	bytes -= runtime->dma_addr;
+
+	frames = bytes_to_frames(runtime, bytes);
+	if (frames >= runtime->buffer_size)
+		frames -= runtime->buffer_size;
+
+	return frames;
+}
+
+static irqreturn_t abdac_interrupt(int irq, void *dev_id)
+{
+	struct atmel_abdac *dac = dev_id;
+	u32 status;
+
+	status = dac_readl(dac, INT_STATUS);
+	if (status & DAC_BIT(UNDERRUN)) {
+		dev_err(&dac->pdev->dev, "underrun detected\n");
+		dac_writel(dac, INT_CLR, DAC_BIT(UNDERRUN));
+	} else {
+		dev_err(&dac->pdev->dev, "spurious interrupt (status=0x%x)\n",
+			status);
+		dac_writel(dac, INT_CLR, status);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static struct snd_pcm_ops atmel_abdac_ops = {
+	.open		= atmel_abdac_open,
+	.close		= atmel_abdac_close,
+	.ioctl		= snd_pcm_lib_ioctl,
+	.hw_params	= atmel_abdac_hw_params,
+	.hw_free	= atmel_abdac_hw_free,
+	.prepare	= atmel_abdac_prepare,
+	.trigger	= atmel_abdac_trigger,
+	.pointer	= atmel_abdac_pointer,
+};
+
+static int __devinit atmel_abdac_pcm_new(struct atmel_abdac *dac)
+{
+	struct snd_pcm_hardware hw = atmel_abdac_hw;
+	struct snd_pcm *pcm;
+	int retval;
+
+	retval = snd_pcm_new(dac->card, dac->card->shortname,
+			dac->pdev->id, 1, 0, &pcm);
+	if (retval)
+		return retval;
+
+	strcpy(pcm->name, dac->card->shortname);
+	pcm->private_data = dac;
+	pcm->info_flags = 0;
+	dac->pcm = pcm;
+
+	snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &atmel_abdac_ops);
+
+	retval = snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
+			&dac->pdev->dev, hw.periods_min * hw.period_bytes_min,
+			hw.buffer_bytes_max);
+
+	return retval;
+}
+
+static bool filter(struct dma_chan *chan, void *slave)
+{
+	struct dw_dma_slave *dws = slave;
+
+	if (dws->dma_dev == chan->device->dev) {
+		chan->private = dws;
+		return true;
+	} else
+		return false;
+}
+
+static int set_sample_rates(struct atmel_abdac *dac)
+{
+	long new_rate = RATE_MAX;
+	int retval = -EINVAL;
+	int index = 0;
+
+	/* we start at 192 kHz and work our way down to 5112 Hz */
+	while (new_rate >= RATE_MIN && index < (MAX_NUM_RATES + 1)) {
+		new_rate = clk_round_rate(dac->sample_clk, 256 * new_rate);
+		if (new_rate < 0)
+			break;
+		/* make sure we are below the ABDAC clock */
+		if (new_rate <= clk_get_rate(dac->pclk)) {
+			dac->rates[index] = new_rate / 256;
+			index++;
+		}
+		/* divide by 256 and then by two to get next rate */
+		new_rate /= 256 * 2;
+	}
+
+	if (index) {
+		int i;
+
+		/* reverse array, smallest go first */
+		for (i = 0; i < (index / 2); i++) {
+			unsigned int tmp = dac->rates[index - 1 - i];
+			dac->rates[index - 1 - i] = dac->rates[i];
+			dac->rates[i] = tmp;
+		}
+
+		dac->constraints_rates.count = index;
+		dac->constraints_rates.list = dac->rates;
+		dac->constraints_rates.mask = 0;
+		dac->rates_num = index;
+
+		retval = 0;
+	}
+
+	return retval;
+}
+
+static int __devinit atmel_abdac_probe(struct platform_device *pdev)
+{
+	struct snd_card		*card;
+	struct atmel_abdac	*dac;
+	struct resource		*regs;
+	struct atmel_abdac_pdata	*pdata;
+	struct clk		*pclk;
+	struct clk		*sample_clk;
+	int			retval;
+	int			irq;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!regs) {
+		dev_dbg(&pdev->dev, "no memory resource\n");
+		return -ENXIO;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_dbg(&pdev->dev, "could not get IRQ number\n");
+		return irq;
+	}
+
+	pdata = pdev->dev.platform_data;
+	if (!pdata) {
+		dev_dbg(&pdev->dev, "no platform data\n");
+		return -ENXIO;
+	}
+
+	pclk = clk_get(&pdev->dev, "pclk");
+	if (IS_ERR(pclk)) {
+		dev_dbg(&pdev->dev, "no peripheral clock\n");
+		return PTR_ERR(pclk);
+	}
+	sample_clk = clk_get(&pdev->dev, "sample_clk");
+	if (IS_ERR(pclk)) {
+		dev_dbg(&pdev->dev, "no sample clock\n");
+		retval = PTR_ERR(pclk);
+		goto out_put_pclk;
+	}
+	clk_enable(pclk);
+
+	retval = snd_card_create(SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
+			THIS_MODULE, sizeof(struct atmel_abdac), &card);
+	if (retval) {
+		dev_dbg(&pdev->dev, "could not create sound card device\n");
+		goto out_put_sample_clk;
+	}
+
+	dac = get_dac(card);
+
+	dac->irq = irq;
+	dac->card = card;
+	dac->pclk = pclk;
+	dac->sample_clk = sample_clk;
+	dac->pdev = pdev;
+
+	retval = set_sample_rates(dac);
+	if (retval < 0) {
+		dev_dbg(&pdev->dev, "could not set supported rates\n");
+		goto out_free_card;
+	}
+
+	dac->regs = ioremap(regs->start, regs->end - regs->start + 1);
+	if (!dac->regs) {
+		dev_dbg(&pdev->dev, "could not remap register memory\n");
+		goto out_free_card;
+	}
+
+	/* make sure the DAC is silent and disabled */
+	dac_writel(dac, DATA, 0);
+	dac_writel(dac, CTRL, 0);
+
+	retval = request_irq(irq, abdac_interrupt, 0, "abdac", dac);
+	if (retval) {
+		dev_dbg(&pdev->dev, "could not request irq\n");
+		goto out_unmap_regs;
+	}
+
+	snd_card_set_dev(card, &pdev->dev);
+
+	if (pdata->dws.dma_dev) {
+		struct dw_dma_slave *dws = &pdata->dws;
+		dma_cap_mask_t mask;
+
+		dws->tx_reg = regs->start + DAC_DATA;
+
+		dma_cap_zero(mask);
+		dma_cap_set(DMA_SLAVE, mask);
+
+		dac->dma.chan = dma_request_channel(mask, filter, dws);
+	}
+	if (!pdata->dws.dma_dev || !dac->dma.chan) {
+		dev_dbg(&pdev->dev, "DMA not available\n");
+		retval = -ENODEV;
+		goto out_unset_card_dev;
+	}
+
+	strcpy(card->driver, "Atmel ABDAC");
+	strcpy(card->shortname, "Atmel ABDAC");
+	sprintf(card->longname, "Atmel Audio Bitstream DAC");
+
+	retval = atmel_abdac_pcm_new(dac);
+	if (retval) {
+		dev_dbg(&pdev->dev, "could not register ABDAC pcm device\n");
+		goto out_release_dma;
+	}
+
+	retval = snd_card_register(card);
+	if (retval) {
+		dev_dbg(&pdev->dev, "could not register sound card\n");
+		goto out_release_dma;
+	}
+
+	platform_set_drvdata(pdev, card);
+
+	dev_info(&pdev->dev, "Atmel ABDAC at 0x%p using %s\n",
+			dac->regs, dac->dma.chan->dev->device.bus_id);
+
+	return retval;
+
+out_release_dma:
+	dma_release_channel(dac->dma.chan);
+	dac->dma.chan = NULL;
+out_unset_card_dev:
+	snd_card_set_dev(card, NULL);
+	free_irq(irq, dac);
+out_unmap_regs:
+	iounmap(dac->regs);
+out_free_card:
+	snd_card_free(card);
+out_put_sample_clk:
+	clk_put(sample_clk);
+	clk_disable(pclk);
+out_put_pclk:
+	clk_put(pclk);
+	return retval;
+}
+
+#ifdef CONFIG_PM
+static int atmel_abdac_suspend(struct platform_device *pdev, pm_message_t msg)
+{
+	struct snd_card *card = platform_get_drvdata(pdev);
+	struct atmel_abdac *dac = card->private_data;
+
+	dw_dma_cyclic_stop(dac->dma.chan);
+	clk_disable(dac->sample_clk);
+	clk_disable(dac->pclk);
+
+	return 0;
+}
+
+static int atmel_abdac_resume(struct platform_device *pdev)
+{
+	struct snd_card *card = platform_get_drvdata(pdev);
+	struct atmel_abdac *dac = card->private_data;
+
+	clk_enable(dac->pclk);
+	clk_enable(dac->sample_clk);
+	if (test_bit(DMA_READY, &dac->flags))
+		dw_dma_cyclic_start(dac->dma.chan);
+
+	return 0;
+}
+#else
+#define atmel_abdac_suspend NULL
+#define atmel_abdac_resume NULL
+#endif
+
+static int __devexit atmel_abdac_remove(struct platform_device *pdev)
+{
+	struct snd_card *card = platform_get_drvdata(pdev);
+	struct atmel_abdac *dac = get_dac(card);
+
+	clk_put(dac->sample_clk);
+	clk_disable(dac->pclk);
+	clk_put(dac->pclk);
+
+	dma_release_channel(dac->dma.chan);
+	dac->dma.chan = NULL;
+	snd_card_set_dev(card, NULL);
+	iounmap(dac->regs);
+	free_irq(dac->irq, dac);
+	snd_card_free(card);
+
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static struct platform_driver atmel_abdac_driver = {
+	.remove		= __devexit_p(atmel_abdac_remove),
+	.driver		= {
+		.name	= "atmel_abdac",
+	},
+	.suspend	= atmel_abdac_suspend,
+	.resume		= atmel_abdac_resume,
+};
+
+static int __init atmel_abdac_init(void)
+{
+	return platform_driver_probe(&atmel_abdac_driver,
+			atmel_abdac_probe);
+}
+module_init(atmel_abdac_init);
+
+static void __exit atmel_abdac_exit(void)
+{
+	platform_driver_unregister(&atmel_abdac_driver);
+}
+module_exit(atmel_abdac_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Driver for Atmel Audio Bitstream DAC (ABDAC)");
+MODULE_AUTHOR("Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>");