/* * 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 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 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"); retval = -ENOMEM; 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_SLEEP static int atmel_abdac_suspend(struct device *pdev) { struct snd_card *card = dev_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 device *pdev) { struct snd_card *card = dev_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; } static SIMPLE_DEV_PM_OPS(atmel_abdac_pm, atmel_abdac_suspend, atmel_abdac_resume); #define ATMEL_ABDAC_PM_OPS &atmel_abdac_pm #else #define ATMEL_ABDAC_PM_OPS NULL #endif static int 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 = atmel_abdac_remove, .driver = { .name = "atmel_abdac", .owner = THIS_MODULE, .pm = ATMEL_ABDAC_PM_OPS, }, }; 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>");