diff options
Diffstat (limited to 'sound/soc/adi/axi-i2s.c')
-rw-r--r-- | sound/soc/adi/axi-i2s.c | 276 |
1 files changed, 276 insertions, 0 deletions
diff --git a/sound/soc/adi/axi-i2s.c b/sound/soc/adi/axi-i2s.c new file mode 100644 index 0000000..6058c1f --- /dev/null +++ b/sound/soc/adi/axi-i2s.c @@ -0,0 +1,276 @@ +/* + * Copyright (C) 2012-2013, Analog Devices Inc. + * Author: Lars-Peter Clausen <lars@metafoo.de> + * + * Licensed under the GPL-2. + */ + +#include <linux/clk.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/slab.h> + +#include <sound/core.h> +#include <sound/pcm.h> +#include <sound/pcm_params.h> +#include <sound/soc.h> +#include <sound/dmaengine_pcm.h> + +#define AXI_I2S_REG_RESET 0x00 +#define AXI_I2S_REG_CTRL 0x04 +#define AXI_I2S_REG_CLK_CTRL 0x08 +#define AXI_I2S_REG_STATUS 0x10 + +#define AXI_I2S_REG_RX_FIFO 0x28 +#define AXI_I2S_REG_TX_FIFO 0x2C + +#define AXI_I2S_RESET_GLOBAL BIT(0) +#define AXI_I2S_RESET_TX_FIFO BIT(1) +#define AXI_I2S_RESET_RX_FIFO BIT(2) + +#define AXI_I2S_CTRL_TX_EN BIT(0) +#define AXI_I2S_CTRL_RX_EN BIT(1) + +/* The frame size is configurable, but for now we always set it 64 bit */ +#define AXI_I2S_BITS_PER_FRAME 64 + +struct axi_i2s { + struct regmap *regmap; + struct clk *clk; + struct clk *clk_ref; + + struct snd_soc_dai_driver dai_driver; + + struct snd_dmaengine_dai_dma_data capture_dma_data; + struct snd_dmaengine_dai_dma_data playback_dma_data; + + struct snd_ratnum ratnum; + struct snd_pcm_hw_constraint_ratnums rate_constraints; +}; + +static int axi_i2s_trigger(struct snd_pcm_substream *substream, int cmd, + struct snd_soc_dai *dai) +{ + struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai); + unsigned int mask, val; + + if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) + mask = AXI_I2S_CTRL_RX_EN; + else + mask = AXI_I2S_CTRL_TX_EN; + + switch (cmd) { + case SNDRV_PCM_TRIGGER_START: + case SNDRV_PCM_TRIGGER_RESUME: + case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: + val = mask; + break; + case SNDRV_PCM_TRIGGER_STOP: + case SNDRV_PCM_TRIGGER_SUSPEND: + case SNDRV_PCM_TRIGGER_PAUSE_PUSH: + val = 0; + break; + default: + return -EINVAL; + } + + regmap_update_bits(i2s->regmap, AXI_I2S_REG_CTRL, mask, val); + + return 0; +} + +static int axi_i2s_hw_params(struct snd_pcm_substream *substream, + struct snd_pcm_hw_params *params, struct snd_soc_dai *dai) +{ + struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai); + unsigned int bclk_div, word_size; + unsigned int bclk_rate; + + bclk_rate = params_rate(params) * AXI_I2S_BITS_PER_FRAME; + + word_size = AXI_I2S_BITS_PER_FRAME / 2 - 1; + bclk_div = DIV_ROUND_UP(clk_get_rate(i2s->clk_ref), bclk_rate) / 2 - 1; + + regmap_write(i2s->regmap, AXI_I2S_REG_CLK_CTRL, (word_size << 16) | + bclk_div); + + return 0; +} + +static int axi_i2s_startup(struct snd_pcm_substream *substream, + struct snd_soc_dai *dai) +{ + struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai); + uint32_t mask; + int ret; + + if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) + mask = AXI_I2S_RESET_RX_FIFO; + else + mask = AXI_I2S_RESET_TX_FIFO; + + regmap_write(i2s->regmap, AXI_I2S_REG_RESET, mask); + + ret = snd_pcm_hw_constraint_ratnums(substream->runtime, 0, + SNDRV_PCM_HW_PARAM_RATE, + &i2s->rate_constraints); + if (ret) + return ret; + + return clk_prepare_enable(i2s->clk_ref); +} + +static void axi_i2s_shutdown(struct snd_pcm_substream *substream, + struct snd_soc_dai *dai) +{ + struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai); + + clk_disable_unprepare(i2s->clk_ref); +} + +static int axi_i2s_dai_probe(struct snd_soc_dai *dai) +{ + struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai); + + snd_soc_dai_init_dma_data(dai, &i2s->playback_dma_data, + &i2s->capture_dma_data); + + return 0; +} + +static const struct snd_soc_dai_ops axi_i2s_dai_ops = { + .startup = axi_i2s_startup, + .shutdown = axi_i2s_shutdown, + .trigger = axi_i2s_trigger, + .hw_params = axi_i2s_hw_params, +}; + +static struct snd_soc_dai_driver axi_i2s_dai = { + .probe = axi_i2s_dai_probe, + .playback = { + .channels_min = 2, + .channels_max = 2, + .rates = SNDRV_PCM_RATE_KNOT, + .formats = SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_U32_LE, + }, + .capture = { + .channels_min = 2, + .channels_max = 2, + .rates = SNDRV_PCM_RATE_KNOT, + .formats = SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_U32_LE, + }, + .ops = &axi_i2s_dai_ops, + .symmetric_rates = 1, +}; + +static const struct snd_soc_component_driver axi_i2s_component = { + .name = "axi-i2s", +}; + +static const struct regmap_config axi_i2s_regmap_config = { + .reg_bits = 32, + .reg_stride = 4, + .val_bits = 32, + .max_register = AXI_I2S_REG_STATUS, +}; + +static int axi_i2s_probe(struct platform_device *pdev) +{ + struct resource *res; + struct axi_i2s *i2s; + void __iomem *base; + int ret; + + i2s = devm_kzalloc(&pdev->dev, sizeof(*i2s), GFP_KERNEL); + if (!i2s) + return -ENOMEM; + + platform_set_drvdata(pdev, i2s); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(base)) + return PTR_ERR(base); + + i2s->regmap = devm_regmap_init_mmio(&pdev->dev, base, + &axi_i2s_regmap_config); + if (IS_ERR(i2s->regmap)) + return PTR_ERR(i2s->regmap); + + i2s->clk = devm_clk_get(&pdev->dev, "axi"); + if (IS_ERR(i2s->clk)) + return PTR_ERR(i2s->clk); + + i2s->clk_ref = devm_clk_get(&pdev->dev, "ref"); + if (IS_ERR(i2s->clk_ref)) + return PTR_ERR(i2s->clk_ref); + + ret = clk_prepare_enable(i2s->clk); + if (ret) + return ret; + + i2s->playback_dma_data.addr = res->start + AXI_I2S_REG_TX_FIFO; + i2s->playback_dma_data.addr_width = 4; + i2s->playback_dma_data.maxburst = 1; + + i2s->capture_dma_data.addr = res->start + AXI_I2S_REG_RX_FIFO; + i2s->capture_dma_data.addr_width = 4; + i2s->capture_dma_data.maxburst = 1; + + i2s->ratnum.num = clk_get_rate(i2s->clk_ref) / 2 / AXI_I2S_BITS_PER_FRAME; + i2s->ratnum.den_step = 1; + i2s->ratnum.den_min = 1; + i2s->ratnum.den_max = 64; + + i2s->rate_constraints.rats = &i2s->ratnum; + i2s->rate_constraints.nrats = 1; + + regmap_write(i2s->regmap, AXI_I2S_REG_RESET, AXI_I2S_RESET_GLOBAL); + + ret = devm_snd_soc_register_component(&pdev->dev, &axi_i2s_component, + &axi_i2s_dai, 1); + if (ret) + goto err_clk_disable; + + ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0); + if (ret) + goto err_clk_disable; + +err_clk_disable: + clk_disable_unprepare(i2s->clk); + return ret; +} + +static int axi_i2s_dev_remove(struct platform_device *pdev) +{ + struct axi_i2s *i2s = platform_get_drvdata(pdev); + + clk_disable_unprepare(i2s->clk); + + return 0; +} + +static const struct of_device_id axi_i2s_of_match[] = { + { .compatible = "adi,axi-i2s-1.00.a", }, + {}, +}; +MODULE_DEVICE_TABLE(of, axi_i2s_of_match); + +static struct platform_driver axi_i2s_driver = { + .driver = { + .name = "axi-i2s", + .owner = THIS_MODULE, + .of_match_table = axi_i2s_of_match, + }, + .probe = axi_i2s_probe, + .remove = axi_i2s_dev_remove, +}; +module_platform_driver(axi_i2s_driver); + +MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); +MODULE_DESCRIPTION("AXI I2S driver"); +MODULE_LICENSE("GPL"); |