--- /dev/null
+/*
+ * ASoC driver for Cirrus Logic EP93xx AC97 controller.
+ *
+ * Copyright (c) 2010 Mika Westerberg
+ *
+ * Based on s3c-ac97 ASoC driver by Jaswinder Singh.
+ *
+ * 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/delay.h>
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include <sound/core.h>
+#include <sound/ac97_codec.h>
+#include <sound/soc.h>
+
+#include <mach/dma.h>
+#include "ep93xx-pcm.h"
+
+/*
+ * Per channel (1-4) registers.
+ */
+#define AC97CH(n) (((n) - 1) * 0x20)
+
+#define AC97DR(n) (AC97CH(n) + 0x0000)
+
+#define AC97RXCR(n) (AC97CH(n) + 0x0004)
+#define AC97RXCR_REN BIT(0)
+#define AC97RXCR_RX3 BIT(3)
+#define AC97RXCR_RX4 BIT(4)
+#define AC97RXCR_CM BIT(15)
+
+#define AC97TXCR(n) (AC97CH(n) + 0x0008)
+#define AC97TXCR_TEN BIT(0)
+#define AC97TXCR_TX3 BIT(3)
+#define AC97TXCR_TX4 BIT(4)
+#define AC97TXCR_CM BIT(15)
+
+#define AC97SR(n) (AC97CH(n) + 0x000c)
+#define AC97SR_TXFE BIT(1)
+#define AC97SR_TXUE BIT(6)
+
+#define AC97RISR(n) (AC97CH(n) + 0x0010)
+#define AC97ISR(n) (AC97CH(n) + 0x0014)
+#define AC97IE(n) (AC97CH(n) + 0x0018)
+
+/*
+ * Global AC97 controller registers.
+ */
+#define AC97S1DATA 0x0080
+#define AC97S2DATA 0x0084
+#define AC97S12DATA 0x0088
+
+#define AC97RGIS 0x008c
+#define AC97GIS 0x0090
+#define AC97IM 0x0094
+/*
+ * Common bits for RGIS, GIS and IM registers.
+ */
+#define AC97_SLOT2RXVALID BIT(1)
+#define AC97_CODECREADY BIT(5)
+#define AC97_SLOT2TXCOMPLETE BIT(6)
+
+#define AC97EOI 0x0098
+#define AC97EOI_WINT BIT(0)
+#define AC97EOI_CODECREADY BIT(1)
+
+#define AC97GCR 0x009c
+#define AC97GCR_AC97IFE BIT(0)
+
+#define AC97RESET 0x00a0
+#define AC97RESET_TIMEDRESET BIT(0)
+
+#define AC97SYNC 0x00a4
+#define AC97SYNC_TIMEDSYNC BIT(0)
+
+#define AC97_TIMEOUT msecs_to_jiffies(5)
+
+/**
+ * struct ep93xx_ac97_info - EP93xx AC97 controller info structure
+ * @lock: mutex serializing access to the bus (slot 1 & 2 ops)
+ * @dev: pointer to the platform device dev structure
+ * @mem: physical memory resource for the registers
+ * @regs: mapped AC97 controller registers
+ * @irq: AC97 interrupt number
+ * @done: bus ops wait here for an interrupt
+ */
+struct ep93xx_ac97_info {
+ struct mutex lock;
+ struct device *dev;
+ struct resource *mem;
+ void __iomem *regs;
+ int irq;
+ struct completion done;
+};
+
+/* currently ALSA only supports a single AC97 device */
+static struct ep93xx_ac97_info *ep93xx_ac97_info;
+
+static struct ep93xx_pcm_dma_params ep93xx_ac97_pcm_out = {
+ .name = "ac97-pcm-out",
+ .dma_port = EP93XX_DMA_M2P_PORT_AAC1,
+};
+
+static struct ep93xx_pcm_dma_params ep93xx_ac97_pcm_in = {
+ .name = "ac97-pcm-in",
+ .dma_port = EP93XX_DMA_M2P_PORT_AAC1,
+};
+
+static inline unsigned ep93xx_ac97_read_reg(struct ep93xx_ac97_info *info,
+ unsigned reg)
+{
+ return __raw_readl(info->regs + reg);
+}
+
+static inline void ep93xx_ac97_write_reg(struct ep93xx_ac97_info *info,
+ unsigned reg, unsigned val)
+{
+ __raw_writel(val, info->regs + reg);
+}
+
+static unsigned short ep93xx_ac97_read(struct snd_ac97 *ac97,
+ unsigned short reg)
+{
+ struct ep93xx_ac97_info *info = ep93xx_ac97_info;
+ unsigned short val;
+
+ mutex_lock(&info->lock);
+
+ ep93xx_ac97_write_reg(info, AC97S1DATA, reg);
+ ep93xx_ac97_write_reg(info, AC97IM, AC97_SLOT2RXVALID);
+ if (!wait_for_completion_timeout(&info->done, AC97_TIMEOUT)) {
+ dev_warn(info->dev, "timeout reading register %x\n", reg);
+ mutex_unlock(&info->lock);
+ return -ETIMEDOUT;
+ }
+ val = (unsigned short)ep93xx_ac97_read_reg(info, AC97S2DATA);
+
+ mutex_unlock(&info->lock);
+ return val;
+}
+
+static void ep93xx_ac97_write(struct snd_ac97 *ac97,
+ unsigned short reg,
+ unsigned short val)
+{
+ struct ep93xx_ac97_info *info = ep93xx_ac97_info;
+
+ mutex_lock(&info->lock);
+
+ /*
+ * Writes to the codec need to be done so that slot 2 is filled in
+ * before slot 1.
+ */
+ ep93xx_ac97_write_reg(info, AC97S2DATA, val);
+ ep93xx_ac97_write_reg(info, AC97S1DATA, reg);
+
+ ep93xx_ac97_write_reg(info, AC97IM, AC97_SLOT2TXCOMPLETE);
+ if (!wait_for_completion_timeout(&info->done, AC97_TIMEOUT))
+ dev_warn(info->dev, "timeout writing register %x\n", reg);
+
+ mutex_unlock(&info->lock);
+}
+
+static void ep93xx_ac97_warm_reset(struct snd_ac97 *ac97)
+{
+ struct ep93xx_ac97_info *info = ep93xx_ac97_info;
+
+ mutex_lock(&info->lock);
+
+ /*
+ * We are assuming that before this functions gets called, the codec
+ * BIT_CLK is stopped by forcing the codec into powerdown mode. We can
+ * control the SYNC signal directly via AC97SYNC register. Using
+ * TIMEDSYNC the controller will keep the SYNC high > 1us.
+ */
+ ep93xx_ac97_write_reg(info, AC97SYNC, AC97SYNC_TIMEDSYNC);
+ ep93xx_ac97_write_reg(info, AC97IM, AC97_CODECREADY);
+ if (!wait_for_completion_timeout(&info->done, AC97_TIMEOUT))
+ dev_warn(info->dev, "codec warm reset timeout\n");
+
+ mutex_unlock(&info->lock);
+}
+
+static void ep93xx_ac97_cold_reset(struct snd_ac97 *ac97)
+{
+ struct ep93xx_ac97_info *info = ep93xx_ac97_info;
+
+ mutex_lock(&info->lock);
+
+ /*
+ * For doing cold reset, we disable the AC97 controller interface, clear
+ * WINT and CODECREADY bits, and finally enable the interface again.
+ */
+ ep93xx_ac97_write_reg(info, AC97GCR, 0);
+ ep93xx_ac97_write_reg(info, AC97EOI, AC97EOI_CODECREADY | AC97EOI_WINT);
+ ep93xx_ac97_write_reg(info, AC97GCR, AC97GCR_AC97IFE);
+
+ /*
+ * Now, assert the reset and wait for the codec to become ready.
+ */
+ ep93xx_ac97_write_reg(info, AC97RESET, AC97RESET_TIMEDRESET);
+ ep93xx_ac97_write_reg(info, AC97IM, AC97_CODECREADY);
+ if (!wait_for_completion_timeout(&info->done, AC97_TIMEOUT))
+ dev_warn(info->dev, "codec cold reset timeout\n");
+
+ /*
+ * Give the codec some time to come fully out from the reset. This way
+ * we ensure that the subsequent reads/writes will work.
+ */
+ usleep_range(15000, 20000);
+
+ mutex_unlock(&info->lock);
+}
+
+static irqreturn_t ep93xx_ac97_interrupt(int irq, void *dev_id)
+{
+ struct ep93xx_ac97_info *info = dev_id;
+ unsigned status, mask;
+
+ /*
+ * Just mask out the interrupt and wake up the waiting thread.
+ * Interrupts are cleared via reading/writing to slot 1 & 2 registers by
+ * the waiting thread.
+ */
+ status = ep93xx_ac97_read_reg(info, AC97GIS);
+ mask = ep93xx_ac97_read_reg(info, AC97IM);
+ mask &= ~status;
+ ep93xx_ac97_write_reg(info, AC97IM, mask);
+
+ complete(&info->done);
+ return IRQ_HANDLED;
+}
+
+struct snd_ac97_bus_ops soc_ac97_ops = {
+ .read = ep93xx_ac97_read,
+ .write = ep93xx_ac97_write,
+ .reset = ep93xx_ac97_cold_reset,
+ .warm_reset = ep93xx_ac97_warm_reset,
+};
+EXPORT_SYMBOL_GPL(soc_ac97_ops);
+
+static int ep93xx_ac97_trigger(struct snd_pcm_substream *substream,
+ int cmd, struct snd_soc_dai *dai)
+{
+ struct ep93xx_ac97_info *info = snd_soc_dai_get_drvdata(dai);
+ unsigned v = 0;
+
+
+ switch (cmd) {
+ case SNDRV_PCM_TRIGGER_START:
+ case SNDRV_PCM_TRIGGER_RESUME:
+ case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+ /*
+ * Enable compact mode, TX slots 3 & 4, and the TX FIFO
+ * itself.
+ */
+ v |= AC97TXCR_CM;
+ v |= AC97TXCR_TX3 | AC97TXCR_TX4;
+ v |= AC97TXCR_TEN;
+ ep93xx_ac97_write_reg(info, AC97TXCR(1), v);
+ } else {
+ /*
+ * Enable compact mode, RX slots 3 & 4, and the RX FIFO
+ * itself.
+ */
+ v |= AC97RXCR_CM;
+ v |= AC97RXCR_RX3 | AC97RXCR_RX4;
+ v |= AC97RXCR_REN;
+ ep93xx_ac97_write_reg(info, AC97RXCR(1), v);
+ }
+ break;
+
+ case SNDRV_PCM_TRIGGER_STOP:
+ case SNDRV_PCM_TRIGGER_SUSPEND:
+ case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+ /*
+ * As per Cirrus EP93xx errata described below:
+ *
+ * http://www.cirrus.com/en/pubs/errata/ER667E2B.pdf
+ *
+ * we will wait for the TX FIFO to be empty before
+ * clearing the TEN bit.
+ */
+ unsigned long timeout = jiffies + AC97_TIMEOUT;
+
+ do {
+ v = ep93xx_ac97_read_reg(info, AC97SR(1));
+ if (time_after(jiffies, timeout)) {
+ dev_warn(info->dev, "TX timeout\n");
+ break;
+ }
+ } while (!(v & (AC97SR_TXFE | AC97SR_TXUE)));
+
+ /* disable the TX FIFO */
+ ep93xx_ac97_write_reg(info, AC97TXCR(1), 0);
+ } else {
+ /* disable the RX FIFO */
+ ep93xx_ac97_write_reg(info, AC97RXCR(1), 0);
+ }
+ break;
+
+ default:
+ dev_warn(info->dev, "unknown command %d\n", cmd);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int ep93xx_ac97_startup(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct ep93xx_pcm_dma_params *dma_data;
+
+ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+ dma_data = &ep93xx_ac97_pcm_out;
+ else
+ dma_data = &ep93xx_ac97_pcm_in;
+
+ snd_soc_dai_set_dma_data(dai, substream, dma_data);
+ return 0;
+}
+
+static struct snd_soc_dai_ops ep93xx_ac97_dai_ops = {
+ .startup = ep93xx_ac97_startup,
+ .trigger = ep93xx_ac97_trigger,
+};
+
+struct snd_soc_dai_driver ep93xx_ac97_dai = {
+ .name = "ep93xx-ac97",
+ .id = 0,
+ .ac97_control = 1,
+ .playback = {
+ .stream_name = "AC97 Playback",
+ .channels_min = 2,
+ .channels_max = 2,
+ .rates = SNDRV_PCM_RATE_8000_48000,
+ .formats = SNDRV_PCM_FMTBIT_S16_LE,
+ },
+ .capture = {
+ .stream_name = "AC97 Capture",
+ .channels_min = 2,
+ .channels_max = 2,
+ .rates = SNDRV_PCM_RATE_8000_48000,
+ .formats = SNDRV_PCM_FMTBIT_S16_LE,
+ },
+ .ops = &ep93xx_ac97_dai_ops,
+};
+
+static int __devinit ep93xx_ac97_probe(struct platform_device *pdev)
+{
+ struct ep93xx_ac97_info *info;
+ int ret;
+
+ info = kzalloc(sizeof(struct ep93xx_ac97_info), GFP_KERNEL);
+ if (!info)
+ return -ENOMEM;
+
+ dev_set_drvdata(&pdev->dev, info);
+
+ mutex_init(&info->lock);
+ init_completion(&info->done);
+ info->dev = &pdev->dev;
+
+ info->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!info->mem) {
+ ret = -ENXIO;
+ goto fail_free_info;
+ }
+
+ info->irq = platform_get_irq(pdev, 0);
+ if (!info->irq) {
+ ret = -ENXIO;
+ goto fail_free_info;
+ }
+
+ if (!request_mem_region(info->mem->start, resource_size(info->mem),
+ pdev->name)) {
+ ret = -EBUSY;
+ goto fail_free_info;
+ }
+
+ info->regs = ioremap(info->mem->start, resource_size(info->mem));
+ if (!info->regs) {
+ ret = -ENOMEM;
+ goto fail_release_mem;
+ }
+
+ ret = request_irq(info->irq, ep93xx_ac97_interrupt, IRQF_TRIGGER_HIGH,
+ pdev->name, info);
+ if (ret)
+ goto fail_unmap_mem;
+
+ ep93xx_ac97_info = info;
+ platform_set_drvdata(pdev, info);
+
+ ret = snd_soc_register_dai(&pdev->dev, &ep93xx_ac97_dai);
+ if (ret)
+ goto fail_free_irq;
+
+ return 0;
+
+fail_free_irq:
+ platform_set_drvdata(pdev, NULL);
+ free_irq(info->irq, info);
+fail_unmap_mem:
+ iounmap(info->regs);
+fail_release_mem:
+ release_mem_region(info->mem->start, resource_size(info->mem));
+fail_free_info:
+ kfree(info);
+
+ return ret;
+}
+
+static int __devexit ep93xx_ac97_remove(struct platform_device *pdev)
+{
+ struct ep93xx_ac97_info *info = platform_get_drvdata(pdev);
+
+ snd_soc_unregister_dai(&pdev->dev);
+
+ /* disable the AC97 controller */
+ ep93xx_ac97_write_reg(info, AC97GCR, 0);
+
+ free_irq(info->irq, info);
+ iounmap(info->regs);
+ release_mem_region(info->mem->start, resource_size(info->mem));
+ platform_set_drvdata(pdev, NULL);
+ kfree(info);
+
+ return 0;
+}
+
+static struct platform_driver ep93xx_ac97_driver = {
+ .probe = ep93xx_ac97_probe,
+ .remove = __devexit_p(ep93xx_ac97_remove),
+ .driver = {
+ .name = "ep93xx-ac97",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init ep93xx_ac97_init(void)
+{
+ return platform_driver_register(&ep93xx_ac97_driver);
+}
+module_init(ep93xx_ac97_init);
+
+static void __exit ep93xx_ac97_exit(void)
+{
+ platform_driver_unregister(&ep93xx_ac97_driver);
+}
+module_exit(ep93xx_ac97_exit);
+
+MODULE_DESCRIPTION("EP93xx AC97 ASoC Driver");
+MODULE_AUTHOR("Mika Westerberg <mika.westerberg@iki.fi>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:ep93xx-ac97");
projects / platform / kernel / linux-rpi.git / commitdiff