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-rw-r--r--sound/soc/bcm/bcm2835-i2s.c935
1 files changed, 935 insertions, 0 deletions
diff --git a/sound/soc/bcm/bcm2835-i2s.c b/sound/soc/bcm/bcm2835-i2s.c
new file mode 100644
index 000000000..dc34fe155
--- /dev/null
+++ b/sound/soc/bcm/bcm2835-i2s.c
@@ -0,0 +1,935 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 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.
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+
+#include <sound/core.h>
+#include <sound/dmaengine_pcm.h>
+#include <sound/initval.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+
+/* 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_CH1_POS(v) BCM2835_I2S_CH1(BCM2835_I2S_CHPOS(v))
+#define BCM2835_I2S_CH2_POS(v) BCM2835_I2S_CH2(BCM2835_I2S_CHPOS(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)
+
+/* Frame length register is 10 bit, maximum length 1024 */
+#define BCM2835_I2S_MAX_FRAME_LENGTH 1024
+
+/* General device struct */
+struct bcm2835_i2s_dev {
+ struct device *dev;
+ struct snd_dmaengine_dai_dma_data dma_data[2];
+ unsigned int fmt;
+ unsigned int tdm_slots;
+ unsigned int rx_mask;
+ unsigned int tx_mask;
+ unsigned int slot_width;
+ unsigned int frame_length;
+
+ struct regmap *i2s_regmap;
+ struct clk *clk;
+ bool clk_prepared;
+ int clk_rate;
+};
+
+static void bcm2835_i2s_start_clock(struct bcm2835_i2s_dev *dev)
+{
+ unsigned int master = dev->fmt & SND_SOC_DAIFMT_MASTER_MASK;
+
+ if (dev->clk_prepared)
+ return;
+
+ switch (master) {
+ case SND_SOC_DAIFMT_CBS_CFS:
+ case SND_SOC_DAIFMT_CBS_CFM:
+ clk_prepare_enable(dev->clk);
+ dev->clk_prepared = true;
+ break;
+ default:
+ break;
+ }
+}
+
+static void bcm2835_i2s_stop_clock(struct bcm2835_i2s_dev *dev)
+{
+ if (dev->clk_prepared)
+ clk_disable_unprepare(dev->clk);
+ dev->clk_prepared = false;
+}
+
+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;
+ bool clk_was_prepared;
+ 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);
+
+ /* Start clock if not running */
+ clk_was_prepared = dev->clk_prepared;
+ if (!clk_was_prepared)
+ bcm2835_i2s_start_clock(dev);
+
+ /* 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_was_prepared)
+ 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);
+
+ if (!ratio) {
+ dev->tdm_slots = 0;
+ return 0;
+ }
+
+ if (ratio > BCM2835_I2S_MAX_FRAME_LENGTH)
+ return -EINVAL;
+
+ dev->tdm_slots = 2;
+ dev->rx_mask = 0x03;
+ dev->tx_mask = 0x03;
+ dev->slot_width = ratio / 2;
+ dev->frame_length = ratio;
+
+ return 0;
+}
+
+static int bcm2835_i2s_set_dai_tdm_slot(struct snd_soc_dai *dai,
+ unsigned int tx_mask, unsigned int rx_mask,
+ int slots, int width)
+{
+ struct bcm2835_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
+
+ if (slots) {
+ if (slots < 0 || width < 0)
+ return -EINVAL;
+
+ /* Limit masks to available slots */
+ rx_mask &= GENMASK(slots - 1, 0);
+ tx_mask &= GENMASK(slots - 1, 0);
+
+ /*
+ * The driver is limited to 2-channel setups.
+ * Check that exactly 2 bits are set in the masks.
+ */
+ if (hweight_long((unsigned long) rx_mask) != 2
+ || hweight_long((unsigned long) tx_mask) != 2)
+ return -EINVAL;
+
+ if (slots * width > BCM2835_I2S_MAX_FRAME_LENGTH)
+ return -EINVAL;
+ }
+
+ dev->tdm_slots = slots;
+
+ dev->rx_mask = rx_mask;
+ dev->tx_mask = tx_mask;
+ dev->slot_width = width;
+ dev->frame_length = slots * width;
+
+ return 0;
+}
+
+/*
+ * Convert logical slot number into physical slot number.
+ *
+ * If odd_offset is 0 sequential number is identical to logical number.
+ * This is used for DSP modes with slot numbering 0 1 2 3 ...
+ *
+ * Otherwise odd_offset defines the physical offset for odd numbered
+ * slots. This is used for I2S and left/right justified modes to
+ * translate from logical slot numbers 0 1 2 3 ... into physical slot
+ * numbers 0 2 ... 3 4 ...
+ */
+static int bcm2835_i2s_convert_slot(unsigned int slot, unsigned int odd_offset)
+{
+ if (!odd_offset)
+ return slot;
+
+ if (slot & 1)
+ return (slot >> 1) + odd_offset;
+
+ return slot >> 1;
+}
+
+/*
+ * Calculate channel position from mask and slot width.
+ *
+ * Mask must contain exactly 2 set bits.
+ * Lowest set bit is channel 1 position, highest set bit channel 2.
+ * The constant offset is added to both channel positions.
+ *
+ * If odd_offset is > 0 slot positions are translated to
+ * I2S-style TDM slot numbering ( 0 2 ... 3 4 ...) with odd
+ * logical slot numbers starting at physical slot odd_offset.
+ */
+static void bcm2835_i2s_calc_channel_pos(
+ unsigned int *ch1_pos, unsigned int *ch2_pos,
+ unsigned int mask, unsigned int width,
+ unsigned int bit_offset, unsigned int odd_offset)
+{
+ *ch1_pos = bcm2835_i2s_convert_slot((ffs(mask) - 1), odd_offset)
+ * width + bit_offset;
+ *ch2_pos = bcm2835_i2s_convert_slot((fls(mask) - 1), odd_offset)
+ * width + bit_offset;
+}
+
+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 data_length, data_delay, framesync_length;
+ unsigned int slots, slot_width, odd_slot_offset;
+ int frame_length, bclk_rate;
+ unsigned int rx_mask, tx_mask;
+ unsigned int rx_ch1_pos, rx_ch2_pos, tx_ch1_pos, tx_ch2_pos;
+ unsigned int mode, format;
+ bool bit_clock_master = false;
+ bool frame_sync_master = false;
+ bool frame_start_falling_edge = false;
+ uint32_t csreg;
+ int ret = 0;
+
+ /*
+ * 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;
+
+ data_length = params_width(params);
+ data_delay = 0;
+ odd_slot_offset = 0;
+ mode = 0;
+
+ if (dev->tdm_slots) {
+ slots = dev->tdm_slots;
+ slot_width = dev->slot_width;
+ frame_length = dev->frame_length;
+ rx_mask = dev->rx_mask;
+ tx_mask = dev->tx_mask;
+ bclk_rate = dev->frame_length * params_rate(params);
+ } else {
+ slots = 2;
+ slot_width = params_width(params);
+ rx_mask = 0x03;
+ tx_mask = 0x03;
+
+ frame_length = snd_soc_params_to_frame_size(params);
+ if (frame_length < 0)
+ return frame_length;
+
+ bclk_rate = snd_soc_params_to_bclk(params);
+ if (bclk_rate < 0)
+ return bclk_rate;
+ }
+
+ /* Check if data fits into slots */
+ if (data_length > slot_width)
+ return -EINVAL;
+
+ /* Check if CPU is bit clock master */
+ switch (dev->fmt & SND_SOC_DAIFMT_MASTER_MASK) {
+ case SND_SOC_DAIFMT_CBS_CFS:
+ case SND_SOC_DAIFMT_CBS_CFM:
+ bit_clock_master = true;
+ break;
+ case SND_SOC_DAIFMT_CBM_CFS:
+ case SND_SOC_DAIFMT_CBM_CFM:
+ bit_clock_master = false;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* Check if CPU is frame sync master */
+ switch (dev->fmt & SND_SOC_DAIFMT_MASTER_MASK) {
+ case SND_SOC_DAIFMT_CBS_CFS:
+ case SND_SOC_DAIFMT_CBM_CFS:
+ frame_sync_master = true;
+ break;
+ case SND_SOC_DAIFMT_CBS_CFM:
+ case SND_SOC_DAIFMT_CBM_CFM:
+ frame_sync_master = false;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* Clock should only be set up here if CPU is clock master */
+ if (bit_clock_master &&
+ (!dev->clk_prepared || dev->clk_rate != bclk_rate)) {
+ if (dev->clk_prepared)
+ bcm2835_i2s_stop_clock(dev);
+
+ if (dev->clk_rate != bclk_rate) {
+ ret = clk_set_rate(dev->clk, bclk_rate);
+ if (ret)
+ return ret;
+ dev->clk_rate = bclk_rate;
+ }
+
+ bcm2835_i2s_start_clock(dev);
+ }
+
+ /* Setup the frame format */
+ format = BCM2835_I2S_CHEN;
+
+ if (data_length >= 24)
+ format |= BCM2835_I2S_CHWEX;
+
+ format |= BCM2835_I2S_CHWID((data_length-8)&0xf);
+
+ /* CH2 format is the same as for CH1 */
+ format = BCM2835_I2S_CH1(format) | BCM2835_I2S_CH2(format);
+
+ switch (dev->fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
+ case SND_SOC_DAIFMT_I2S:
+ /* I2S mode needs an even number of slots */
+ if (slots & 1)
+ return -EINVAL;
+
+ /*
+ * Use I2S-style logical slot numbering: even slots
+ * are in first half of frame, odd slots in second half.
+ */
+ odd_slot_offset = slots >> 1;
+
+ /* MSB starts one cycle after frame start */
+ data_delay = 1;
+
+ /* Setup frame sync signal for 50% duty cycle */
+ framesync_length = frame_length / 2;
+ frame_start_falling_edge = true;
+ break;
+ case SND_SOC_DAIFMT_LEFT_J:
+ if (slots & 1)
+ return -EINVAL;
+
+ odd_slot_offset = slots >> 1;
+ data_delay = 0;
+ framesync_length = frame_length / 2;
+ frame_start_falling_edge = false;
+ break;
+ case SND_SOC_DAIFMT_RIGHT_J:
+ if (slots & 1)
+ return -EINVAL;
+
+ /* Odd frame lengths aren't supported */
+ if (frame_length & 1)
+ return -EINVAL;
+
+ odd_slot_offset = slots >> 1;
+ data_delay = slot_width - data_length;
+ framesync_length = frame_length / 2;
+ frame_start_falling_edge = false;
+ break;
+ case SND_SOC_DAIFMT_DSP_A:
+ data_delay = 1;
+ framesync_length = 1;
+ frame_start_falling_edge = false;
+ break;
+ case SND_SOC_DAIFMT_DSP_B:
+ data_delay = 0;
+ framesync_length = 1;
+ frame_start_falling_edge = false;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ bcm2835_i2s_calc_channel_pos(&rx_ch1_pos, &rx_ch2_pos,
+ rx_mask, slot_width, data_delay, odd_slot_offset);
+ bcm2835_i2s_calc_channel_pos(&tx_ch1_pos, &tx_ch2_pos,
+ tx_mask, slot_width, data_delay, odd_slot_offset);
+
+ /*
+ * Transmitting data immediately after frame start, eg
+ * in left-justified or DSP mode A, only works stable
+ * if bcm2835 is the frame clock master.
+ */
+ if ((!rx_ch1_pos || !tx_ch1_pos) && !frame_sync_master)
+ dev_warn(dev->dev,
+ "Unstable slave config detected, L/R may be swapped");
+
+ /*
+ * 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
+ | BCM2835_I2S_CH1_POS(rx_ch1_pos)
+ | BCM2835_I2S_CH2_POS(rx_ch2_pos));
+ regmap_write(dev->i2s_regmap, BCM2835_I2S_TXC_A_REG,
+ format
+ | BCM2835_I2S_CH1_POS(tx_ch1_pos)
+ | BCM2835_I2S_CH2_POS(tx_ch2_pos));
+
+ /* Setup the I2S mode */
+
+ 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(frame_length - 1);
+ mode |= BCM2835_I2S_FSLEN(framesync_length);
+
+ /* CLKM selects bcm2835 clock slave mode */
+ if (!bit_clock_master)
+ mode |= BCM2835_I2S_CLKM;
+
+ /* FSM selects bcm2835 frame sync slave mode */
+ if (!frame_sync_master)
+ mode |= BCM2835_I2S_FSM;
+
+ /* CLKI selects normal clocking mode, sampling on rising edge */
+ switch (dev->fmt & SND_SOC_DAIFMT_INV_MASK) {
+ case SND_SOC_DAIFMT_NB_NF:
+ case SND_SOC_DAIFMT_NB_IF:
+ mode |= BCM2835_I2S_CLKI;
+ break;
+ case SND_SOC_DAIFMT_IB_NF:
+ case SND_SOC_DAIFMT_IB_IF:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* FSI selects frame start on falling edge */
+ switch (dev->fmt & SND_SOC_DAIFMT_INV_MASK) {
+ case SND_SOC_DAIFMT_NB_NF:
+ case SND_SOC_DAIFMT_IB_NF:
+ if (frame_start_falling_edge)
+ mode |= BCM2835_I2S_FSI;
+ break;
+ case SND_SOC_DAIFMT_NB_IF:
+ case SND_SOC_DAIFMT_IB_IF:
+ if (!frame_start_falling_edge)
+ 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);
+
+ dev_dbg(dev->dev,
+ "slots: %d width: %d rx mask: 0x%02x tx_mask: 0x%02x\n",
+ slots, slot_width, rx_mask, tx_mask);
+
+ dev_dbg(dev->dev, "frame len: %d sync len: %d data len: %d\n",
+ frame_length, framesync_length, data_length);
+
+ dev_dbg(dev->dev, "rx pos: %d,%d tx pos: %d,%d\n",
+ rx_ch1_pos, rx_ch2_pos, tx_ch1_pos, tx_ch2_pos);
+
+ dev_dbg(dev->dev, "sampling rate: %d bclk rate: %d\n",
+ params_rate(params), bclk_rate);
+
+ dev_dbg(dev->dev, "CLKM: %d CLKI: %d FSM: %d FSI: %d frame start: %s edge\n",
+ !!(mode & BCM2835_I2S_CLKM),
+ !!(mode & BCM2835_I2S_CLKI),
+ !!(mode & BCM2835_I2S_FSM),
+ !!(mode & BCM2835_I2S_FSI),
+ (mode & BCM2835_I2S_FSI) ? "falling" : "rising");
+
+ return ret;
+}
+
+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;
+
+ /*
+ * 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 (!snd_soc_dai_active(dai) && !(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 (snd_soc_dai_active(dai))
+ 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 (snd_soc_dai_active(dai))
+ 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,
+ .set_tdm_slot = bcm2835_i2s_set_dai_tdm_slot,
+};
+
+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_CONTINUOUS,
+ .rate_min = 8000,
+ .rate_max = 384000,
+ .formats = SNDRV_PCM_FMTBIT_S16_LE
+ | SNDRV_PCM_FMTBIT_S24_LE
+ | SNDRV_PCM_FMTBIT_S32_LE
+ },
+ .capture = {
+ .channels_min = 2,
+ .channels_max = 2,
+ .rates = SNDRV_PCM_RATE_CONTINUOUS,
+ .rate_min = 8000,
+ .rate_max = 384000,
+ .formats = SNDRV_PCM_FMTBIT_S16_LE
+ | SNDRV_PCM_FMTBIT_S24_LE
+ | SNDRV_PCM_FMTBIT_S32_LE
+ },
+ .ops = &bcm2835_i2s_dai_ops,
+ .symmetric_rates = 1,
+ .symmetric_samplebits = 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 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,
+};
+
+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 ret;
+ void __iomem *base;
+ const __be32 *addr;
+ dma_addr_t dma_base;
+
+ dev = devm_kzalloc(&pdev->dev, sizeof(*dev),
+ GFP_KERNEL);
+ if (!dev)
+ return -ENOMEM;
+
+ /* get the clock */
+ dev->clk_prepared = false;
+ dev->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(dev->clk)) {
+ ret = PTR_ERR(dev->clk);
+ if (ret == -EPROBE_DEFER)
+ dev_dbg(&pdev->dev, "could not get clk: %d\n", ret);
+ else
+ dev_err(&pdev->dev, "could not get clk: %d\n", ret);
+ return ret;
+ }
+
+ /* Request ioarea */
+ base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ dev->i2s_regmap = devm_regmap_init_mmio(&pdev->dev, base,
+ &bcm2835_regmap_config);
+ if (IS_ERR(dev->i2s_regmap))
+ return PTR_ERR(dev->i2s_regmap);
+
+ /* Set the DMA address - we have to parse DT ourselves */
+ addr = of_get_address(pdev->dev.of_node, 0, NULL, NULL);
+ if (!addr) {
+ dev_err(&pdev->dev, "could not get DMA-register address\n");
+ return -EINVAL;
+ }
+ dma_base = be32_to_cpup(addr);
+
+ dev->dma_data[SNDRV_PCM_STREAM_PLAYBACK].addr =
+ dma_base + BCM2835_I2S_FIFO_A_REG;
+
+ dev->dma_data[SNDRV_PCM_STREAM_CAPTURE].addr =
+ dma_base + BCM2835_I2S_FIFO_A_REG;
+
+ /* 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;
+
+ /*
+ * Set the PACK flag to enable S16_LE support (2 S16_LE values
+ * packed into 32-bit transfers).
+ */
+ dev->dma_data[SNDRV_PCM_STREAM_PLAYBACK].flags =
+ SND_DMAENGINE_PCM_DAI_FLAG_PACK;
+ dev->dma_data[SNDRV_PCM_STREAM_CAPTURE].flags =
+ SND_DMAENGINE_PCM_DAI_FLAG_PACK;
+
+ /* 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", },
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, bcm2835_i2s_of_match);
+
+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");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-01 13:43:13 +0000