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linux/sound/soc/tegra/tegra20_ac97.c
Dmitry Osipenko a46b78247b
ASoC: tegra20: ac97: Add reset control 
Tegra20 AC97 driver doesn't manage the AC97 controller reset, relying on
implicit deassertion of the reset by tegra-clk driver, which needs to be
fixed since this behaviour is unacceptable by other Tegra drivers. Add
explicit reset control to the Tegra20 AC97 driver.

Note that AC97 reset was always specified in Tegra20 device-tree, hence
DTB ABI changes aren't required.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Link: https://lore.kernel.org/r/20210314154459.15375-2-digetx@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-03-18 13:49:30 +00:00

463 lines
12 KiB
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// SPDX-License-Identifier: GPL-2.0-only
/*
* tegra20_ac97.c - Tegra20 AC97 platform driver
*
* Copyright (c) 2012 Lucas Stach <dev@lynxeye.de>
*
* Partly based on code copyright/by:
*
* Copyright (c) 2011,2012 Toradex Inc.
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/gpio.h>
#include <linux/io.h>
#include <linux/jiffies.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/reset.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>
#include "tegra20_ac97.h"
#define DRV_NAME "tegra20-ac97"
static struct tegra20_ac97 *workdata;
static void tegra20_ac97_codec_reset(struct snd_ac97 *ac97)
{
u32 readback;
unsigned long timeout;
/* reset line is not driven by DAC pad group, have to toggle GPIO */
gpio_set_value(workdata->reset_gpio, 0);
udelay(2);
gpio_set_value(workdata->reset_gpio, 1);
udelay(2);
timeout = jiffies + msecs_to_jiffies(100);
do {
regmap_read(workdata->regmap, TEGRA20_AC97_STATUS1, &readback);
if (readback & TEGRA20_AC97_STATUS1_CODEC1_RDY)
break;
usleep_range(1000, 2000);
} while (!time_after(jiffies, timeout));
}
static void tegra20_ac97_codec_warm_reset(struct snd_ac97 *ac97)
{
u32 readback;
unsigned long timeout;
/*
* although sync line is driven by the DAC pad group warm reset using
* the controller cmd is not working, have to toggle sync line
* manually.
*/
gpio_request(workdata->sync_gpio, "codec-sync");
gpio_direction_output(workdata->sync_gpio, 1);
udelay(2);
gpio_set_value(workdata->sync_gpio, 0);
udelay(2);
gpio_free(workdata->sync_gpio);
timeout = jiffies + msecs_to_jiffies(100);
do {
regmap_read(workdata->regmap, TEGRA20_AC97_STATUS1, &readback);
if (readback & TEGRA20_AC97_STATUS1_CODEC1_RDY)
break;
usleep_range(1000, 2000);
} while (!time_after(jiffies, timeout));
}
static unsigned short tegra20_ac97_codec_read(struct snd_ac97 *ac97_snd,
unsigned short reg)
{
u32 readback;
unsigned long timeout;
regmap_write(workdata->regmap, TEGRA20_AC97_CMD,
(((reg | 0x80) << TEGRA20_AC97_CMD_CMD_ADDR_SHIFT) &
TEGRA20_AC97_CMD_CMD_ADDR_MASK) |
TEGRA20_AC97_CMD_BUSY);
timeout = jiffies + msecs_to_jiffies(100);
do {
regmap_read(workdata->regmap, TEGRA20_AC97_STATUS1, &readback);
if (readback & TEGRA20_AC97_STATUS1_STA_VALID1)
break;
usleep_range(1000, 2000);
} while (!time_after(jiffies, timeout));
return ((readback & TEGRA20_AC97_STATUS1_STA_DATA1_MASK) >>
TEGRA20_AC97_STATUS1_STA_DATA1_SHIFT);
}
static void tegra20_ac97_codec_write(struct snd_ac97 *ac97_snd,
unsigned short reg, unsigned short val)
{
u32 readback;
unsigned long timeout;
regmap_write(workdata->regmap, TEGRA20_AC97_CMD,
((reg << TEGRA20_AC97_CMD_CMD_ADDR_SHIFT) &
TEGRA20_AC97_CMD_CMD_ADDR_MASK) |
((val << TEGRA20_AC97_CMD_CMD_DATA_SHIFT) &
TEGRA20_AC97_CMD_CMD_DATA_MASK) |
TEGRA20_AC97_CMD_BUSY);
timeout = jiffies + msecs_to_jiffies(100);
do {
regmap_read(workdata->regmap, TEGRA20_AC97_CMD, &readback);
if (!(readback & TEGRA20_AC97_CMD_BUSY))
break;
usleep_range(1000, 2000);
} while (!time_after(jiffies, timeout));
}
static struct snd_ac97_bus_ops tegra20_ac97_ops = {
.read = tegra20_ac97_codec_read,
.write = tegra20_ac97_codec_write,
.reset = tegra20_ac97_codec_reset,
.warm_reset = tegra20_ac97_codec_warm_reset,
};
static inline void tegra20_ac97_start_playback(struct tegra20_ac97 *ac97)
{
regmap_update_bits(ac97->regmap, TEGRA20_AC97_FIFO1_SCR,
TEGRA20_AC97_FIFO_SCR_PB_QRT_MT_EN,
TEGRA20_AC97_FIFO_SCR_PB_QRT_MT_EN);
regmap_update_bits(ac97->regmap, TEGRA20_AC97_CTRL,
TEGRA20_AC97_CTRL_PCM_DAC_EN |
TEGRA20_AC97_CTRL_STM_EN,
TEGRA20_AC97_CTRL_PCM_DAC_EN |
TEGRA20_AC97_CTRL_STM_EN);
}
static inline void tegra20_ac97_stop_playback(struct tegra20_ac97 *ac97)
{
regmap_update_bits(ac97->regmap, TEGRA20_AC97_FIFO1_SCR,
TEGRA20_AC97_FIFO_SCR_PB_QRT_MT_EN, 0);
regmap_update_bits(ac97->regmap, TEGRA20_AC97_CTRL,
TEGRA20_AC97_CTRL_PCM_DAC_EN, 0);
}
static inline void tegra20_ac97_start_capture(struct tegra20_ac97 *ac97)
{
regmap_update_bits(ac97->regmap, TEGRA20_AC97_FIFO1_SCR,
TEGRA20_AC97_FIFO_SCR_REC_FULL_EN,
TEGRA20_AC97_FIFO_SCR_REC_FULL_EN);
}
static inline void tegra20_ac97_stop_capture(struct tegra20_ac97 *ac97)
{
regmap_update_bits(ac97->regmap, TEGRA20_AC97_FIFO1_SCR,
TEGRA20_AC97_FIFO_SCR_REC_FULL_EN, 0);
}
static int tegra20_ac97_trigger(struct snd_pcm_substream *substream, int cmd,
struct snd_soc_dai *dai)
{
struct tegra20_ac97 *ac97 = snd_soc_dai_get_drvdata(dai);
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
case SNDRV_PCM_TRIGGER_RESUME:
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
tegra20_ac97_start_playback(ac97);
else
tegra20_ac97_start_capture(ac97);
break;
case SNDRV_PCM_TRIGGER_STOP:
case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
case SNDRV_PCM_TRIGGER_SUSPEND:
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
tegra20_ac97_stop_playback(ac97);
else
tegra20_ac97_stop_capture(ac97);
break;
default:
return -EINVAL;
}
return 0;
}
static const struct snd_soc_dai_ops tegra20_ac97_dai_ops = {
.trigger = tegra20_ac97_trigger,
};
static int tegra20_ac97_probe(struct snd_soc_dai *dai)
{
struct tegra20_ac97 *ac97 = snd_soc_dai_get_drvdata(dai);
dai->capture_dma_data = &ac97->capture_dma_data;
dai->playback_dma_data = &ac97->playback_dma_data;
return 0;
}
static struct snd_soc_dai_driver tegra20_ac97_dai = {
.name = "tegra-ac97-pcm",
.probe = tegra20_ac97_probe,
.playback = {
.stream_name = "PCM Playback",
.channels_min = 2,
.channels_max = 2,
.rates = SNDRV_PCM_RATE_8000_48000,
.formats = SNDRV_PCM_FMTBIT_S16_LE,
},
.capture = {
.stream_name = "PCM Capture",
.channels_min = 2,
.channels_max = 2,
.rates = SNDRV_PCM_RATE_8000_48000,
.formats = SNDRV_PCM_FMTBIT_S16_LE,
},
.ops = &tegra20_ac97_dai_ops,
};
static const struct snd_soc_component_driver tegra20_ac97_component = {
.name = DRV_NAME,
};
static bool tegra20_ac97_wr_rd_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
case TEGRA20_AC97_CTRL:
case TEGRA20_AC97_CMD:
case TEGRA20_AC97_STATUS1:
case TEGRA20_AC97_FIFO1_SCR:
case TEGRA20_AC97_FIFO_TX1:
case TEGRA20_AC97_FIFO_RX1:
return true;
default:
break;
}
return false;
}
static bool tegra20_ac97_volatile_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
case TEGRA20_AC97_STATUS1:
case TEGRA20_AC97_FIFO1_SCR:
case TEGRA20_AC97_FIFO_TX1:
case TEGRA20_AC97_FIFO_RX1:
return true;
default:
break;
}
return false;
}
static bool tegra20_ac97_precious_reg(struct device *dev, unsigned int reg)
{
switch (reg) {
case TEGRA20_AC97_FIFO_TX1:
case TEGRA20_AC97_FIFO_RX1:
return true;
default:
break;
}
return false;
}
static const struct regmap_config tegra20_ac97_regmap_config = {
.reg_bits = 32,
.reg_stride = 4,
.val_bits = 32,
.max_register = TEGRA20_AC97_FIFO_RX1,
.writeable_reg = tegra20_ac97_wr_rd_reg,
.readable_reg = tegra20_ac97_wr_rd_reg,
.volatile_reg = tegra20_ac97_volatile_reg,
.precious_reg = tegra20_ac97_precious_reg,
.cache_type = REGCACHE_FLAT,
};
static int tegra20_ac97_platform_probe(struct platform_device *pdev)
{
struct tegra20_ac97 *ac97;
struct resource *mem;
void __iomem *regs;
int ret = 0;
ac97 = devm_kzalloc(&pdev->dev, sizeof(struct tegra20_ac97),
GFP_KERNEL);
if (!ac97) {
ret = -ENOMEM;
goto err;
}
dev_set_drvdata(&pdev->dev, ac97);
ac97->reset = devm_reset_control_get_exclusive(&pdev->dev, "ac97");
if (IS_ERR(ac97->reset)) {
dev_err(&pdev->dev, "Can't retrieve ac97 reset\n");
return PTR_ERR(ac97->reset);
}
ac97->clk_ac97 = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(ac97->clk_ac97)) {
dev_err(&pdev->dev, "Can't retrieve ac97 clock\n");
ret = PTR_ERR(ac97->clk_ac97);
goto err;
}
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
regs = devm_ioremap_resource(&pdev->dev, mem);
if (IS_ERR(regs)) {
ret = PTR_ERR(regs);
goto err_clk_put;
}
ac97->regmap = devm_regmap_init_mmio(&pdev->dev, regs,
&tegra20_ac97_regmap_config);
if (IS_ERR(ac97->regmap)) {
dev_err(&pdev->dev, "regmap init failed\n");
ret = PTR_ERR(ac97->regmap);
goto err_clk_put;
}
ac97->reset_gpio = of_get_named_gpio(pdev->dev.of_node,
"nvidia,codec-reset-gpio", 0);
if (gpio_is_valid(ac97->reset_gpio)) {
ret = devm_gpio_request_one(&pdev->dev, ac97->reset_gpio,
GPIOF_OUT_INIT_HIGH, "codec-reset");
if (ret) {
dev_err(&pdev->dev, "could not get codec-reset GPIO\n");
goto err_clk_put;
}
} else {
dev_err(&pdev->dev, "no codec-reset GPIO supplied\n");
goto err_clk_put;
}
ac97->sync_gpio = of_get_named_gpio(pdev->dev.of_node,
"nvidia,codec-sync-gpio", 0);
if (!gpio_is_valid(ac97->sync_gpio)) {
dev_err(&pdev->dev, "no codec-sync GPIO supplied\n");
goto err_clk_put;
}
ac97->capture_dma_data.addr = mem->start + TEGRA20_AC97_FIFO_RX1;
ac97->capture_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
ac97->capture_dma_data.maxburst = 4;
ac97->playback_dma_data.addr = mem->start + TEGRA20_AC97_FIFO_TX1;
ac97->playback_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
ac97->playback_dma_data.maxburst = 4;
ret = reset_control_assert(ac97->reset);
if (ret) {
dev_err(&pdev->dev, "Failed to assert AC'97 reset: %d\n", ret);
goto err_clk_put;
}
ret = clk_prepare_enable(ac97->clk_ac97);
if (ret) {
dev_err(&pdev->dev, "clk_enable failed: %d\n", ret);
goto err_clk_put;
}
usleep_range(10, 100);
ret = reset_control_deassert(ac97->reset);
if (ret) {
dev_err(&pdev->dev, "Failed to deassert AC'97 reset: %d\n", ret);
goto err_clk_disable_unprepare;
}
ret = snd_soc_set_ac97_ops(&tegra20_ac97_ops);
if (ret) {
dev_err(&pdev->dev, "Failed to set AC'97 ops: %d\n", ret);
goto err_clk_disable_unprepare;
}
ret = snd_soc_register_component(&pdev->dev, &tegra20_ac97_component,
&tegra20_ac97_dai, 1);
if (ret) {
dev_err(&pdev->dev, "Could not register DAI: %d\n", ret);
ret = -ENOMEM;
goto err_clk_disable_unprepare;
}
ret = tegra_pcm_platform_register(&pdev->dev);
if (ret) {
dev_err(&pdev->dev, "Could not register PCM: %d\n", ret);
goto err_unregister_component;
}
/* XXX: crufty ASoC AC97 API - only one AC97 codec allowed */
workdata = ac97;
return 0;
err_unregister_component:
snd_soc_unregister_component(&pdev->dev);
err_clk_disable_unprepare:
clk_disable_unprepare(ac97->clk_ac97);
err_clk_put:
err:
snd_soc_set_ac97_ops(NULL);
return ret;
}
static int tegra20_ac97_platform_remove(struct platform_device *pdev)
{
struct tegra20_ac97 *ac97 = dev_get_drvdata(&pdev->dev);
tegra_pcm_platform_unregister(&pdev->dev);
snd_soc_unregister_component(&pdev->dev);
clk_disable_unprepare(ac97->clk_ac97);
snd_soc_set_ac97_ops(NULL);
return 0;
}
static const struct of_device_id tegra20_ac97_of_match[] = {
{ .compatible = "nvidia,tegra20-ac97", },
{},
};
static struct platform_driver tegra20_ac97_driver = {
.driver = {
.name = DRV_NAME,
.of_match_table = tegra20_ac97_of_match,
},
.probe = tegra20_ac97_platform_probe,
.remove = tegra20_ac97_platform_remove,
};
module_platform_driver(tegra20_ac97_driver);
MODULE_AUTHOR("Lucas Stach");
MODULE_DESCRIPTION("Tegra20 AC97 ASoC driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" DRV_NAME);
MODULE_DEVICE_TABLE(of, tegra20_ac97_of_match);
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