--- /dev/null
+/*
+ * ALSA SoC I2S Audio Layer for Broadcom BCM2835 SoC
+ *
+ * Author: Florian Meier <florian.meier@koalo.de>
+ * Copyright 2013
+ *
+ * Based on
+ * Raspberry Pi PCM I2S ALSA Driver
+ * Copyright (c) by Phil Poole 2013
+ *
+ * ALSA SoC I2S (McBSP) Audio Layer for TI DAVINCI processor
+ * Vladimir Barinov, <vbarinov@embeddedalley.com>
+ * Copyright (C) 2007 MontaVista Software, Inc., <source@mvista.com>
+ *
+ * OMAP ALSA SoC DAI driver using McBSP port
+ * Copyright (C) 2008 Nokia Corporation
+ * Contact: Jarkko Nikula <jarkko.nikula@bitmer.com>
+ * Peter Ujfalusi <peter.ujfalusi@ti.com>
+ *
+ * Freescale SSI ALSA SoC Digital Audio Interface (DAI) driver
+ * Author: Timur Tabi <timur@freescale.com>
+ * Copyright 2007-2010 Freescale Semiconductor, 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.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/initval.h>
+#include <sound/soc.h>
+#include <sound/dmaengine_pcm.h>
+
+/* Clock registers */
+#define BCM2835_CLK_PCMCTL_REG 0x00
+#define BCM2835_CLK_PCMDIV_REG 0x04
+
+/* Clock register settings */
+#define BCM2835_CLK_PASSWD (0x5a000000)
+#define BCM2835_CLK_PASSWD_MASK (0xff000000)
+#define BCM2835_CLK_MASH(v) ((v) << 9)
+#define BCM2835_CLK_FLIP BIT(8)
+#define BCM2835_CLK_BUSY BIT(7)
+#define BCM2835_CLK_KILL BIT(5)
+#define BCM2835_CLK_ENAB BIT(4)
+#define BCM2835_CLK_SRC(v) (v)
+
+#define BCM2835_CLK_SHIFT (12)
+#define BCM2835_CLK_DIVI(v) ((v) << BCM2835_CLK_SHIFT)
+#define BCM2835_CLK_DIVF(v) (v)
+#define BCM2835_CLK_DIVF_MASK (0xFFF)
+
+enum {
+ BCM2835_CLK_MASH_0 = 0,
+ BCM2835_CLK_MASH_1,
+ BCM2835_CLK_MASH_2,
+ BCM2835_CLK_MASH_3,
+};
+
+enum {
+ BCM2835_CLK_SRC_GND = 0,
+ BCM2835_CLK_SRC_OSC,
+ BCM2835_CLK_SRC_DBG0,
+ BCM2835_CLK_SRC_DBG1,
+ BCM2835_CLK_SRC_PLLA,
+ BCM2835_CLK_SRC_PLLC,
+ BCM2835_CLK_SRC_PLLD,
+ BCM2835_CLK_SRC_HDMI,
+};
+
+/* Most clocks are not useable (freq = 0) */
+static const unsigned int bcm2835_clk_freq[BCM2835_CLK_SRC_HDMI+1] = {
+ [BCM2835_CLK_SRC_GND] = 0,
+ [BCM2835_CLK_SRC_OSC] = 19200000,
+ [BCM2835_CLK_SRC_DBG0] = 0,
+ [BCM2835_CLK_SRC_DBG1] = 0,
+ [BCM2835_CLK_SRC_PLLA] = 0,
+ [BCM2835_CLK_SRC_PLLC] = 0,
+ [BCM2835_CLK_SRC_PLLD] = 500000000,
+ [BCM2835_CLK_SRC_HDMI] = 0,
+};
+
+/* I2S registers */
+#define BCM2835_I2S_CS_A_REG 0x00
+#define BCM2835_I2S_FIFO_A_REG 0x04
+#define BCM2835_I2S_MODE_A_REG 0x08
+#define BCM2835_I2S_RXC_A_REG 0x0c
+#define BCM2835_I2S_TXC_A_REG 0x10
+#define BCM2835_I2S_DREQ_A_REG 0x14
+#define BCM2835_I2S_INTEN_A_REG 0x18
+#define BCM2835_I2S_INTSTC_A_REG 0x1c
+#define BCM2835_I2S_GRAY_REG 0x20
+
+/* I2S register settings */
+#define BCM2835_I2S_STBY BIT(25)
+#define BCM2835_I2S_SYNC BIT(24)
+#define BCM2835_I2S_RXSEX BIT(23)
+#define BCM2835_I2S_RXF BIT(22)
+#define BCM2835_I2S_TXE BIT(21)
+#define BCM2835_I2S_RXD BIT(20)
+#define BCM2835_I2S_TXD BIT(19)
+#define BCM2835_I2S_RXR BIT(18)
+#define BCM2835_I2S_TXW BIT(17)
+#define BCM2835_I2S_CS_RXERR BIT(16)
+#define BCM2835_I2S_CS_TXERR BIT(15)
+#define BCM2835_I2S_RXSYNC BIT(14)
+#define BCM2835_I2S_TXSYNC BIT(13)
+#define BCM2835_I2S_DMAEN BIT(9)
+#define BCM2835_I2S_RXTHR(v) ((v) << 7)
+#define BCM2835_I2S_TXTHR(v) ((v) << 5)
+#define BCM2835_I2S_RXCLR BIT(4)
+#define BCM2835_I2S_TXCLR BIT(3)
+#define BCM2835_I2S_TXON BIT(2)
+#define BCM2835_I2S_RXON BIT(1)
+#define BCM2835_I2S_EN (1)
+
+#define BCM2835_I2S_CLKDIS BIT(28)
+#define BCM2835_I2S_PDMN BIT(27)
+#define BCM2835_I2S_PDME BIT(26)
+#define BCM2835_I2S_FRXP BIT(25)
+#define BCM2835_I2S_FTXP BIT(24)
+#define BCM2835_I2S_CLKM BIT(23)
+#define BCM2835_I2S_CLKI BIT(22)
+#define BCM2835_I2S_FSM BIT(21)
+#define BCM2835_I2S_FSI BIT(20)
+#define BCM2835_I2S_FLEN(v) ((v) << 10)
+#define BCM2835_I2S_FSLEN(v) (v)
+
+#define BCM2835_I2S_CHWEX BIT(15)
+#define BCM2835_I2S_CHEN BIT(14)
+#define BCM2835_I2S_CHPOS(v) ((v) << 4)
+#define BCM2835_I2S_CHWID(v) (v)
+#define BCM2835_I2S_CH1(v) ((v) << 16)
+#define BCM2835_I2S_CH2(v) (v)
+
+#define BCM2835_I2S_TX_PANIC(v) ((v) << 24)
+#define BCM2835_I2S_RX_PANIC(v) ((v) << 16)
+#define BCM2835_I2S_TX(v) ((v) << 8)
+#define BCM2835_I2S_RX(v) (v)
+
+#define BCM2835_I2S_INT_RXERR BIT(3)
+#define BCM2835_I2S_INT_TXERR BIT(2)
+#define BCM2835_I2S_INT_RXR BIT(1)
+#define BCM2835_I2S_INT_TXW BIT(0)
+
+/* I2S DMA interface */
+/* FIXME: Needs IOMMU support */
+#define BCM2835_VCMMU_SHIFT (0x7E000000 - 0x20000000)
+
+/* General device struct */
+struct bcm2835_i2s_dev {
+ struct device *dev;
+ struct snd_dmaengine_dai_dma_data dma_data[2];
+ unsigned int fmt;
+ unsigned int bclk_ratio;
+
+ struct regmap *i2s_regmap;
+ struct regmap *clk_regmap;
+};
+
+static void bcm2835_i2s_start_clock(struct bcm2835_i2s_dev *dev)
+{
+ /* Start the clock if in master mode */
+ unsigned int master = dev->fmt & SND_SOC_DAIFMT_MASTER_MASK;
+
+ switch (master) {
+ case SND_SOC_DAIFMT_CBS_CFS:
+ case SND_SOC_DAIFMT_CBS_CFM:
+ regmap_update_bits(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG,
+ BCM2835_CLK_PASSWD_MASK | BCM2835_CLK_ENAB,
+ BCM2835_CLK_PASSWD | BCM2835_CLK_ENAB);
+ break;
+ default:
+ break;
+ }
+}
+
+static void bcm2835_i2s_stop_clock(struct bcm2835_i2s_dev *dev)
+{
+ uint32_t clkreg;
+ int timeout = 1000;
+
+ /* Stop clock */
+ regmap_update_bits(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG,
+ BCM2835_CLK_PASSWD_MASK | BCM2835_CLK_ENAB,
+ BCM2835_CLK_PASSWD);
+
+ /* Wait for the BUSY flag going down */
+ while (--timeout) {
+ regmap_read(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG, &clkreg);
+ if (!(clkreg & BCM2835_CLK_BUSY))
+ break;
+ }
+
+ if (!timeout) {
+ /* KILL the clock */
+ dev_err(dev->dev, "I2S clock didn't stop. Kill the clock!\n");
+ regmap_update_bits(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG,
+ BCM2835_CLK_KILL | BCM2835_CLK_PASSWD_MASK,
+ BCM2835_CLK_KILL | BCM2835_CLK_PASSWD);
+ }
+}
+
+static void bcm2835_i2s_clear_fifos(struct bcm2835_i2s_dev *dev,
+ bool tx, bool rx)
+{
+ int timeout = 1000;
+ uint32_t syncval;
+ uint32_t csreg;
+ uint32_t i2s_active_state;
+ uint32_t clkreg;
+ uint32_t clk_active_state;
+ uint32_t off;
+ uint32_t clr;
+
+ off = tx ? BCM2835_I2S_TXON : 0;
+ off |= rx ? BCM2835_I2S_RXON : 0;
+
+ clr = tx ? BCM2835_I2S_TXCLR : 0;
+ clr |= rx ? BCM2835_I2S_RXCLR : 0;
+
+ /* Backup the current state */
+ regmap_read(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, &csreg);
+ i2s_active_state = csreg & (BCM2835_I2S_RXON | BCM2835_I2S_TXON);
+
+ regmap_read(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG, &clkreg);
+ clk_active_state = clkreg & BCM2835_CLK_ENAB;
+
+ /* Start clock if not running */
+ if (!clk_active_state) {
+ regmap_update_bits(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG,
+ BCM2835_CLK_PASSWD_MASK | BCM2835_CLK_ENAB,
+ BCM2835_CLK_PASSWD | BCM2835_CLK_ENAB);
+ }
+
+ /* Stop I2S module */
+ regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, off, 0);
+
+ /*
+ * Clear the FIFOs
+ * Requires at least 2 PCM clock cycles to take effect
+ */
+ regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, clr, clr);
+
+ /* Wait for 2 PCM clock cycles */
+
+ /*
+ * Toggle the SYNC flag. After 2 PCM clock cycles it can be read back
+ * FIXME: This does not seem to work for slave mode!
+ */
+ regmap_read(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, &syncval);
+ syncval &= BCM2835_I2S_SYNC;
+
+ regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG,
+ BCM2835_I2S_SYNC, ~syncval);
+
+ /* Wait for the SYNC flag changing it's state */
+ while (--timeout) {
+ regmap_read(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, &csreg);
+ if ((csreg & BCM2835_I2S_SYNC) != syncval)
+ break;
+ }
+
+ if (!timeout)
+ dev_err(dev->dev, "I2S SYNC error!\n");
+
+ /* Stop clock if it was not running before */
+ if (!clk_active_state)
+ bcm2835_i2s_stop_clock(dev);
+
+ /* Restore I2S state */
+ regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG,
+ BCM2835_I2S_RXON | BCM2835_I2S_TXON, i2s_active_state);
+}
+
+static int bcm2835_i2s_set_dai_fmt(struct snd_soc_dai *dai,
+ unsigned int fmt)
+{
+ struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
+ dev->fmt = fmt;
+ return 0;
+}
+
+static int bcm2835_i2s_set_dai_bclk_ratio(struct snd_soc_dai *dai,
+ unsigned int ratio)
+{
+ struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
+ dev->bclk_ratio = ratio;
+ return 0;
+}
+
+static int bcm2835_i2s_hw_params(struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params,
+ struct snd_soc_dai *dai)
+{
+ struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
+
+ unsigned int sampling_rate = params_rate(params);
+ unsigned int data_length, data_delay, bclk_ratio;
+ unsigned int ch1pos, ch2pos, mode, format;
+ unsigned int mash = BCM2835_CLK_MASH_1;
+ unsigned int divi, divf, target_frequency;
+ int clk_src = -1;
+ unsigned int master = dev->fmt & SND_SOC_DAIFMT_MASTER_MASK;
+ bool bit_master = (master == SND_SOC_DAIFMT_CBS_CFS
+ || master == SND_SOC_DAIFMT_CBS_CFM);
+
+ bool frame_master = (master == SND_SOC_DAIFMT_CBS_CFS
+ || master == SND_SOC_DAIFMT_CBM_CFS);
+ uint32_t csreg;
+
+ /*
+ * If a stream is already enabled,
+ * the registers are already set properly.
+ */
+ regmap_read(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, &csreg);
+
+ if (csreg & (BCM2835_I2S_TXON | BCM2835_I2S_RXON))
+ return 0;
+
+ /*
+ * Adjust the data length according to the format.
+ * We prefill the half frame length with an integer
+ * divider of 2400 as explained at the clock settings.
+ * Maybe it is overwritten there, if the Integer mode
+ * does not apply.
+ */
+ switch (params_format(params)) {
+ case SNDRV_PCM_FORMAT_S16_LE:
+ data_length = 16;
+ bclk_ratio = 40;
+ break;
+ case SNDRV_PCM_FORMAT_S32_LE:
+ data_length = 32;
+ bclk_ratio = 80;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* If bclk_ratio already set, use that one. */
+ if (dev->bclk_ratio)
+ bclk_ratio = dev->bclk_ratio;
+
+ /*
+ * Clock Settings
+ *
+ * The target frequency of the bit clock is
+ * sampling rate * frame length
+ *
+ * Integer mode:
+ * Sampling rates that are multiples of 8000 kHz
+ * can be driven by the oscillator of 19.2 MHz
+ * with an integer divider as long as the frame length
+ * is an integer divider of 19200000/8000=2400 as set up above.
+ * This is no longer possible if the sampling rate
+ * is too high (e.g. 192 kHz), because the oscillator is too slow.
+ *
+ * MASH mode:
+ * For all other sampling rates, it is not possible to
+ * have an integer divider. Approximate the clock
+ * with the MASH module that induces a slight frequency
+ * variance. To minimize that it is best to have the fastest
+ * clock here. That is PLLD with 500 MHz.
+ */
+ target_frequency = sampling_rate * bclk_ratio;
+ clk_src = BCM2835_CLK_SRC_OSC;
+ mash = BCM2835_CLK_MASH_0;
+
+ if (bcm2835_clk_freq[clk_src] % target_frequency == 0
+ && bit_master && frame_master) {
+ divi = bcm2835_clk_freq[clk_src] / target_frequency;
+ divf = 0;
+ } else {
+ uint64_t dividend;
+
+ if (!dev->bclk_ratio) {
+ /*
+ * Overwrite bclk_ratio, because the
+ * above trick is not needed or can
+ * not be used.
+ */
+ bclk_ratio = 2 * data_length;
+ }
+
+ target_frequency = sampling_rate * bclk_ratio;
+
+ clk_src = BCM2835_CLK_SRC_PLLD;
+ mash = BCM2835_CLK_MASH_1;
+
+ dividend = bcm2835_clk_freq[clk_src];
+ dividend <<= BCM2835_CLK_SHIFT;
+ do_div(dividend, target_frequency);
+ divi = dividend >> BCM2835_CLK_SHIFT;
+ divf = dividend & BCM2835_CLK_DIVF_MASK;
+ }
+
+ /* Set clock divider */
+ regmap_write(dev->clk_regmap, BCM2835_CLK_PCMDIV_REG, BCM2835_CLK_PASSWD
+ | BCM2835_CLK_DIVI(divi)
+ | BCM2835_CLK_DIVF(divf));
+
+ /* Setup clock, but don't start it yet */
+ regmap_write(dev->clk_regmap, BCM2835_CLK_PCMCTL_REG, BCM2835_CLK_PASSWD
+ | BCM2835_CLK_MASH(mash)
+ | BCM2835_CLK_SRC(clk_src));
+
+ /* Setup the frame format */
+ format = BCM2835_I2S_CHEN;
+
+ if (data_length > 24)
+ format |= BCM2835_I2S_CHWEX;
+
+ format |= BCM2835_I2S_CHWID((data_length-8)&0xf);
+
+ switch (dev->fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
+ case SND_SOC_DAIFMT_I2S:
+ data_delay = 1;
+ break;
+ default:
+ /*
+ * TODO
+ * Others are possible but are not implemented at the moment.
+ */
+ dev_err(dev->dev, "%s:bad format\n", __func__);
+ return -EINVAL;
+ }
+
+ ch1pos = data_delay;
+ ch2pos = bclk_ratio / 2 + data_delay;
+
+ switch (params_channels(params)) {
+ case 2:
+ format = BCM2835_I2S_CH1(format) | BCM2835_I2S_CH2(format);
+ format |= BCM2835_I2S_CH1(BCM2835_I2S_CHPOS(ch1pos));
+ format |= BCM2835_I2S_CH2(BCM2835_I2S_CHPOS(ch2pos));
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /*
+ * Set format for both streams.
+ * We cannot set another frame length
+ * (and therefore word length) anyway,
+ * so the format will be the same.
+ */
+ regmap_write(dev->i2s_regmap, BCM2835_I2S_RXC_A_REG, format);
+ regmap_write(dev->i2s_regmap, BCM2835_I2S_TXC_A_REG, format);
+
+ /* Setup the I2S mode */
+ mode = 0;
+
+ if (data_length <= 16) {
+ /*
+ * Use frame packed mode (2 channels per 32 bit word)
+ * We cannot set another frame length in the second stream
+ * (and therefore word length) anyway,
+ * so the format will be the same.
+ */
+ mode |= BCM2835_I2S_FTXP | BCM2835_I2S_FRXP;
+ }
+
+ mode |= BCM2835_I2S_FLEN(bclk_ratio - 1);
+ mode |= BCM2835_I2S_FSLEN(bclk_ratio / 2);
+
+ /* Master or slave? */
+ switch (dev->fmt & SND_SOC_DAIFMT_MASTER_MASK) {
+ case SND_SOC_DAIFMT_CBS_CFS:
+ /* CPU is master */
+ break;
+ case SND_SOC_DAIFMT_CBM_CFS:
+ /*
+ * CODEC is bit clock master
+ * CPU is frame master
+ */
+ mode |= BCM2835_I2S_CLKM;
+ break;
+ case SND_SOC_DAIFMT_CBS_CFM:
+ /*
+ * CODEC is frame master
+ * CPU is bit clock master
+ */
+ mode |= BCM2835_I2S_FSM;
+ break;
+ case SND_SOC_DAIFMT_CBM_CFM:
+ /* CODEC is master */
+ mode |= BCM2835_I2S_CLKM;
+ mode |= BCM2835_I2S_FSM;
+ break;
+ default:
+ dev_err(dev->dev, "%s:bad master\n", __func__);
+ return -EINVAL;
+ }
+
+ /*
+ * Invert clocks?
+ *
+ * The BCM approach seems to be inverted to the classical I2S approach.
+ */
+ switch (dev->fmt & SND_SOC_DAIFMT_INV_MASK) {
+ case SND_SOC_DAIFMT_NB_NF:
+ /* None. Therefore, both for BCM */
+ mode |= BCM2835_I2S_CLKI;
+ mode |= BCM2835_I2S_FSI;
+ break;
+ case SND_SOC_DAIFMT_IB_IF:
+ /* Both. Therefore, none for BCM */
+ break;
+ case SND_SOC_DAIFMT_NB_IF:
+ /*
+ * Invert only frame sync. Therefore,
+ * invert only bit clock for BCM
+ */
+ mode |= BCM2835_I2S_CLKI;
+ break;
+ case SND_SOC_DAIFMT_IB_NF:
+ /*
+ * Invert only bit clock. Therefore,
+ * invert only frame sync for BCM
+ */
+ mode |= BCM2835_I2S_FSI;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ regmap_write(dev->i2s_regmap, BCM2835_I2S_MODE_A_REG, mode);
+
+ /* Setup the DMA parameters */
+ regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG,
+ BCM2835_I2S_RXTHR(1)
+ | BCM2835_I2S_TXTHR(1)
+ | BCM2835_I2S_DMAEN, 0xffffffff);
+
+ regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_DREQ_A_REG,
+ BCM2835_I2S_TX_PANIC(0x10)
+ | BCM2835_I2S_RX_PANIC(0x30)
+ | BCM2835_I2S_TX(0x30)
+ | BCM2835_I2S_RX(0x20), 0xffffffff);
+
+ /* Clear FIFOs */
+ bcm2835_i2s_clear_fifos(dev, true, true);
+
+ return 0;
+}
+
+static int bcm2835_i2s_prepare(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
+ uint32_t cs_reg;
+
+ bcm2835_i2s_start_clock(dev);
+
+ /*
+ * Clear both FIFOs if the one that should be started
+ * is not empty at the moment. This should only happen
+ * after overrun. Otherwise, hw_params would have cleared
+ * the FIFO.
+ */
+ regmap_read(dev->i2s_regmap, BCM2835_I2S_CS_A_REG, &cs_reg);
+
+ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK
+ && !(cs_reg & BCM2835_I2S_TXE))
+ bcm2835_i2s_clear_fifos(dev, true, false);
+ else if (substream->stream == SNDRV_PCM_STREAM_CAPTURE
+ && (cs_reg & BCM2835_I2S_RXD))
+ bcm2835_i2s_clear_fifos(dev, false, true);
+
+ return 0;
+}
+
+static void bcm2835_i2s_stop(struct bcm2835_i2s_dev *dev,
+ struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ uint32_t mask;
+
+ if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
+ mask = BCM2835_I2S_RXON;
+ else
+ mask = BCM2835_I2S_TXON;
+
+ regmap_update_bits(dev->i2s_regmap,
+ BCM2835_I2S_CS_A_REG, mask, 0);
+
+ /* Stop also the clock when not SND_SOC_DAIFMT_CONT */
+ if (!dai->active && !(dev->fmt & SND_SOC_DAIFMT_CONT))
+ bcm2835_i2s_stop_clock(dev);
+}
+
+static int bcm2835_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
+ struct snd_soc_dai *dai)
+{
+ struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
+ uint32_t mask;
+
+ switch (cmd) {
+ case SNDRV_PCM_TRIGGER_START:
+ case SNDRV_PCM_TRIGGER_RESUME:
+ case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+ bcm2835_i2s_start_clock(dev);
+
+ if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
+ mask = BCM2835_I2S_RXON;
+ else
+ mask = BCM2835_I2S_TXON;
+
+ regmap_update_bits(dev->i2s_regmap,
+ BCM2835_I2S_CS_A_REG, mask, mask);
+ break;
+
+ case SNDRV_PCM_TRIGGER_STOP:
+ case SNDRV_PCM_TRIGGER_SUSPEND:
+ case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+ bcm2835_i2s_stop(dev, substream, dai);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int bcm2835_i2s_startup(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
+
+ if (dai->active)
+ return 0;
+
+ /* Should this still be running stop it */
+ bcm2835_i2s_stop_clock(dev);
+
+ /* Enable PCM block */
+ regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG,
+ BCM2835_I2S_EN, BCM2835_I2S_EN);
+
+ /*
+ * Disable STBY.
+ * Requires at least 4 PCM clock cycles to take effect.
+ */
+ regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG,
+ BCM2835_I2S_STBY, BCM2835_I2S_STBY);
+
+ return 0;
+}
+
+static void bcm2835_i2s_shutdown(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
+
+ bcm2835_i2s_stop(dev, substream, dai);
+
+ /* If both streams are stopped, disable module and clock */
+ if (dai->active)
+ return;
+
+ /* Disable the module */
+ regmap_update_bits(dev->i2s_regmap, BCM2835_I2S_CS_A_REG,
+ BCM2835_I2S_EN, 0);
+
+ /*
+ * Stopping clock is necessary, because stop does
+ * not stop the clock when SND_SOC_DAIFMT_CONT
+ */
+ bcm2835_i2s_stop_clock(dev);
+}
+
+static const struct snd_soc_dai_ops bcm2835_i2s_dai_ops = {
+ .startup = bcm2835_i2s_startup,
+ .shutdown = bcm2835_i2s_shutdown,
+ .prepare = bcm2835_i2s_prepare,
+ .trigger = bcm2835_i2s_trigger,
+ .hw_params = bcm2835_i2s_hw_params,
+ .set_fmt = bcm2835_i2s_set_dai_fmt,
+ .set_bclk_ratio = bcm2835_i2s_set_dai_bclk_ratio
+};
+
+static int bcm2835_i2s_dai_probe(struct snd_soc_dai *dai)
+{
+ struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
+
+ snd_soc_dai_init_dma_data(dai,
+ &dev->dma_data[SNDRV_PCM_STREAM_PLAYBACK],
+ &dev->dma_data[SNDRV_PCM_STREAM_CAPTURE]);
+
+ return 0;
+}
+
+static struct snd_soc_dai_driver bcm2835_i2s_dai = {
+ .name = "bcm2835-i2s",
+ .probe = bcm2835_i2s_dai_probe,
+ .playback = {
+ .channels_min = 2,
+ .channels_max = 2,
+ .rates = SNDRV_PCM_RATE_8000_192000,
+ .formats = SNDRV_PCM_FMTBIT_S16_LE
+ | SNDRV_PCM_FMTBIT_S32_LE
+ },
+ .capture = {
+ .channels_min = 2,
+ .channels_max = 2,
+ .rates = SNDRV_PCM_RATE_8000_192000,
+ .formats = SNDRV_PCM_FMTBIT_S16_LE
+ | SNDRV_PCM_FMTBIT_S32_LE
+ },
+ .ops = &bcm2835_i2s_dai_ops,
+ .symmetric_rates = 1
+};
+
+static bool bcm2835_i2s_volatile_reg(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case BCM2835_I2S_CS_A_REG:
+ case BCM2835_I2S_FIFO_A_REG:
+ case BCM2835_I2S_INTSTC_A_REG:
+ case BCM2835_I2S_GRAY_REG:
+ return true;
+ default:
+ return false;
+ };
+}
+
+static bool bcm2835_i2s_precious_reg(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case BCM2835_I2S_FIFO_A_REG:
+ return true;
+ default:
+ return false;
+ };
+}
+
+static bool bcm2835_clk_volatile_reg(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case BCM2835_CLK_PCMCTL_REG:
+ return true;
+ default:
+ return false;
+ };
+}
+
+static const struct regmap_config bcm2835_regmap_config[] = {
+ {
+ .reg_bits = 32,
+ .reg_stride = 4,
+ .val_bits = 32,
+ .max_register = BCM2835_I2S_GRAY_REG,
+ .precious_reg = bcm2835_i2s_precious_reg,
+ .volatile_reg = bcm2835_i2s_volatile_reg,
+ .cache_type = REGCACHE_RBTREE,
+ },
+ {
+ .reg_bits = 32,
+ .reg_stride = 4,
+ .val_bits = 32,
+ .max_register = BCM2835_CLK_PCMDIV_REG,
+ .volatile_reg = bcm2835_clk_volatile_reg,
+ .cache_type = REGCACHE_RBTREE,
+ },
+};
+
+static const struct snd_soc_component_driver bcm2835_i2s_component = {
+ .name = "bcm2835-i2s-comp",
+};
+
+static int bcm2835_i2s_probe(struct platform_device *pdev)
+{
+ struct bcm2835_i2s_dev *dev;
+ int i;
+ int ret;
+ struct regmap *regmap[2];
+ struct resource *mem[2];
+
+ /* Request both ioareas */
+ for (i = 0; i <= 1; i++) {
+ void __iomem *base;
+
+ mem[i] = platform_get_resource(pdev, IORESOURCE_MEM, i);
+ base = devm_ioremap_resource(&pdev->dev, mem[i]);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ regmap[i] = devm_regmap_init_mmio(&pdev->dev, base,
+ &bcm2835_regmap_config[i]);
+ if (IS_ERR(regmap[i]))
+ return PTR_ERR(regmap[i]);
+ }
+
+ dev = devm_kzalloc(&pdev->dev, sizeof(*dev),
+ GFP_KERNEL);
+ if (!dev)
+ return -ENOMEM;
+
+ dev->i2s_regmap = regmap[0];
+ dev->clk_regmap = regmap[1];
+
+ /* Set the DMA address */
+ dev->dma_data[SNDRV_PCM_STREAM_PLAYBACK].addr =
+ (dma_addr_t)mem[0]->start + BCM2835_I2S_FIFO_A_REG
+ + BCM2835_VCMMU_SHIFT;
+
+ dev->dma_data[SNDRV_PCM_STREAM_CAPTURE].addr =
+ (dma_addr_t)mem[0]->start + BCM2835_I2S_FIFO_A_REG
+ + BCM2835_VCMMU_SHIFT;
+
+ /* Set the bus width */
+ dev->dma_data[SNDRV_PCM_STREAM_PLAYBACK].addr_width =
+ DMA_SLAVE_BUSWIDTH_4_BYTES;
+ dev->dma_data[SNDRV_PCM_STREAM_CAPTURE].addr_width =
+ DMA_SLAVE_BUSWIDTH_4_BYTES;
+
+ /* Set burst */
+ dev->dma_data[SNDRV_PCM_STREAM_PLAYBACK].maxburst = 2;
+ dev->dma_data[SNDRV_PCM_STREAM_CAPTURE].maxburst = 2;
+
+ /* BCLK ratio - use default */
+ dev->bclk_ratio = 0;
+
+ /* Store the pdev */
+ dev->dev = &pdev->dev;
+ dev_set_drvdata(&pdev->dev, dev);
+
+ ret = devm_snd_soc_register_component(&pdev->dev,
+ &bcm2835_i2s_component, &bcm2835_i2s_dai, 1);
+ if (ret) {
+ dev_err(&pdev->dev, "Could not register DAI: %d\n", ret);
+ return ret;
+ }
+
+ ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
+ if (ret) {
+ dev_err(&pdev->dev, "Could not register PCM: %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct of_device_id bcm2835_i2s_of_match[] = {
+ { .compatible = "brcm,bcm2835-i2s", },
+ {},
+};
+
+static struct platform_driver bcm2835_i2s_driver = {
+ .probe = bcm2835_i2s_probe,
+ .driver = {
+ .name = "bcm2835-i2s",
+ .of_match_table = bcm2835_i2s_of_match,
+ },
+};
+
+module_platform_driver(bcm2835_i2s_driver);
+
+MODULE_ALIAS("platform:bcm2835-i2s");
+MODULE_DESCRIPTION("BCM2835 I2S interface");
+MODULE_AUTHOR("Florian Meier <florian.meier@koalo.de>");
+MODULE_LICENSE("GPL v2");
Code Review / kvmfornfv.git / blobdiff