| /* |
| * 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/types.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_MEM_TO_DEV); |
| 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 = 6, |
| .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(sample_clk)) { |
| dev_dbg(&pdev->dev, "no sample clock\n"); |
| retval = PTR_ERR(sample_clk); |
| 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, resource_size(regs)); |
| 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) { |
| dma_cap_mask_t mask; |
| |
| dma_cap_zero(mask); |
| dma_cap_set(DMA_SLAVE, mask); |
| |
| dac->dma.chan = dma_request_channel(mask, filter, &pdata->dws); |
| if (dac->dma.chan) { |
| struct dma_slave_config dma_conf = { |
| .dst_addr = regs->start + DAC_DATA, |
| .dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES, |
| .src_maxburst = 1, |
| .dst_maxburst = 1, |
| .direction = DMA_MEM_TO_DEV, |
| .device_fc = false, |
| }; |
| |
| dmaengine_slave_config(dac->dma.chan, &dma_conf); |
| } |
| } |
| 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, dev_name(&dac->dma.chan->dev->device)); |
| |
| 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", |
| .owner = THIS_MODULE, |
| }, |
| .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 <egtvedt@samfundet.no>"); |