[Letux-kernel] [Internal RFC 15/16] ASoC: omap3pandora: Rewrite sound card driver as a platform driver
H. Nikolaus Schaller
hns at goldelico.com
Wed Sep 7 20:01:54 CEST 2022
From: Grond <grond66 at riseup.net>
This change takes advantage of numerous prior changes and moves a
significant amount of code into the new PCM1773 codec driver (and removes
a hardcoded GPIO and regulator in the process). By using this new driver we
can remove the prior fiction that playback audio goes through the TWL4030.
Previously, the sound card driver worked by checking (through various means)
if it was running on the Pandora, and if so, it would create a new platform
device from nothing to function as the sound card, and rely on some weirdness
to get registered as an ASoC card driver. This has not been the way to do ASoC
card drivers for a while now, so instead we register a platform driver which
matches a device in the Pandora's DT and registers the appropriate ASoC card
driver when found. This also means that the driver will only load when the DT
says that we need it, and we can stop manually loading this thing.
Signed-off-by: Grond <grond66 at riseup.net>
Signed-off-by: H. Nikolaus Schaller <hns at goldelico.com>
---
sound/soc/ti/omap3pandora.c | 430 +++++++++++++++++++++++++++---------
1 file changed, 326 insertions(+), 104 deletions(-)
diff --git a/sound/soc/ti/omap3pandora.c b/sound/soc/ti/omap3pandora.c
index 7c35d0b7863e4..f668936265f6b 100644
--- a/sound/soc/ti/omap3pandora.c
+++ b/sound/soc/ti/omap3pandora.c
@@ -11,6 +11,7 @@
#include <linux/delay.h>
#include <linux/regulator/consumer.h>
#include <linux/module.h>
+#include <linux/of_gpio.h>
#include <sound/core.h>
#include <sound/pcm.h>
@@ -18,83 +19,263 @@
#include <asm/mach-types.h>
#include <linux/platform_data/asoc-ti-mcbsp.h>
+#include <linux/mfd/twl4030-audio.h>
#include "omap-mcbsp.h"
-#define OMAP3_PANDORA_DAC_POWER_GPIO 118
-#define OMAP3_PANDORA_AMP_POWER_GPIO 14
+#define AMP_GPIO_NAME "amp-gpio"
-#define PREFIX "ASoC omap3pandora: "
+struct omap3pandora_sound {
+ int amp_gpio;
+ struct regulator *amp_regulator;
-static struct regulator *omap3pandora_dac_reg;
+ struct snd_pcm_substream *playback_stream;
+ struct snd_pcm_substream *capture_stream;
-static int omap3pandora_hw_params(struct snd_pcm_substream *substream,
+ struct mutex sample_rate_lock; // protects all fields after
+ unsigned int sample_rate;
+ int sample_rate_users;
+};
+
+static struct snd_soc_dai_link omap3pandora_dai[];
+
+static int omap3pandora_common_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params)
{
struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
- struct snd_soc_dai *codec_dai = asoc_rtd_to_codec(rtd, 0);
struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(rtd, 0);
+ struct device *dev = rtd->dev;
int ret;
- /* Set the codec system clock for DAC and ADC */
- ret = snd_soc_dai_set_sysclk(codec_dai, 0, 26000000,
- SND_SOC_CLOCK_IN);
- if (ret < 0) {
- pr_err(PREFIX "can't set codec system clock\n");
- return ret;
- }
-
/* Set McBSP clock to external */
ret = snd_soc_dai_set_sysclk(cpu_dai, OMAP_MCBSP_SYSCLK_CLKS_EXT,
256 * params_rate(params),
SND_SOC_CLOCK_IN);
if (ret < 0) {
- pr_err(PREFIX "can't set cpu system clock\n");
+ dev_err(dev, "cannot set McBSP clock to external: %d\n", ret);
return ret;
}
ret = snd_soc_dai_set_clkdiv(cpu_dai, OMAP_MCBSP_CLKGDV, 8);
if (ret < 0) {
- pr_err(PREFIX "can't set SRG clock divider\n");
+ dev_err(dev, "cannot set McBSP clock divider: %d\n", ret);
return ret;
}
return 0;
}
-static int omap3pandora_dac_event(struct snd_soc_dapm_widget *w,
- struct snd_kcontrol *k, int event)
+static inline int constrain_sample_rate(struct snd_pcm_substream *substream,
+ unsigned int sample_rate)
+{
+ return snd_pcm_hw_constraint_single(substream->runtime,
+ SNDRV_PCM_HW_PARAM_RATE,
+ sample_rate);
+}
+
+static inline void relax_sample_rate(struct snd_pcm_substream *substream)
+{
+ const struct snd_interval default_sample_rate_range = {
+ .min = substream->runtime->hw.rate_min,
+ .max = substream->runtime->hw.rate_max,
+ .openmin = 1,
+ .openmax = 1,
+ };
+
+ *constrs_interval(&substream->runtime->hw_constraints,
+ SNDRV_PCM_HW_PARAM_RATE) =
+ default_sample_rate_range;
+}
+
+static void release_sample_rate(struct omap3pandora_sound *ctx,
+ struct snd_pcm_substream *substream)
+{
+ mutex_lock(&ctx->sample_rate_lock);
+
+ if (ctx->sample_rate_users > 0)
+ --ctx->sample_rate_users;
+ if (ctx->sample_rate_users == 0)
+ ctx->sample_rate = 0;
+
+ relax_sample_rate(substream);
+
+ mutex_unlock(&ctx->sample_rate_lock);
+}
+
+static int grab_sample_rate(struct omap3pandora_sound *ctx,
+ struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params)
+{
+ struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+ struct device *dev = rtd->dev;
+ int ret;
+
+ ret = mutex_lock_interruptible(&ctx->sample_rate_lock);
+ if (ret)
+ return ret;
+
+ if (++ctx->sample_rate_users == 1)
+ ctx->sample_rate = params_rate(params);
+
+ mutex_unlock(&ctx->sample_rate_lock);
+
+ ret = constrain_sample_rate(substream, ctx->sample_rate);
+ if (ret < 0)
+ goto err;
+
+ ret = constrain_sample_rate(substream, params_rate(params));
+ if (ret < 0) {
+ dev_dbg(dev, "attempted to use sample rate different from other active substream; on the Pandora, this is impossible, as capture and playback use the same sample clock");
+ goto err;
+ }
+
+ return 0;
+
+err:
+ release_sample_rate(ctx, substream);
+
+ return ret;
+}
+
+static int omap3pandora_playback_hw_params(struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params)
{
+ struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+ struct snd_soc_card *card = rtd->card;
+ struct omap3pandora_sound *ctx = snd_soc_card_get_drvdata(card);
+ struct device *dev = rtd->dev;
+ struct snd_soc_pcm_runtime *tmp_rtd;
+ struct snd_soc_pcm_runtime *twl4030_rtd = NULL;
int ret;
/*
- * The PCM1773 DAC datasheet requires 1ms delay between switching
- * VCC power on/off and /PD pin high/low
+ * We need to set the APLL clock rate on the TWL4030 because it feeds
+ * both the DAI of the PCM1773. So find the appropriate RTD and call
+ * the TWL's .set_sysclk callback through there. Ugly, but it must be
+ * done.
*/
- if (SND_SOC_DAPM_EVENT_ON(event)) {
- ret = regulator_enable(omap3pandora_dac_reg);
- if (ret) {
- dev_err(w->dapm->dev, "Failed to power DAC: %d\n", ret);
- return ret;
+ for_each_card_rtds(card, tmp_rtd)
+ if (tmp_rtd->dai_link == &omap3pandora_dai[1]) {
+ twl4030_rtd = tmp_rtd;
+ break;
}
- mdelay(1);
- gpio_set_value(OMAP3_PANDORA_DAC_POWER_GPIO, 1);
- } else {
- gpio_set_value(OMAP3_PANDORA_DAC_POWER_GPIO, 0);
- mdelay(1);
- regulator_disable(omap3pandora_dac_reg);
+ if (!twl4030_rtd) {
+ dev_err(dev, "cannot find TWL4030 runtime data to set APLL rate\n");
+ return -EINVAL;
+ }
+
+ ret = snd_soc_dai_set_sysclk(asoc_rtd_to_codec(twl4030_rtd, 0),
+ TWL4030_CLOCK_APLL, params_rate(params),
+ SND_SOC_CLOCK_OUT);
+ if (ret) {
+ dev_err(dev, "cannot set TWL4030 APLL rate via set_sysclk interface: %d\n",
+ ret);
+ return ret;
+ }
+
+ if (!ctx->playback_stream) {
+ ctx->playback_stream = substream;
+ ret = grab_sample_rate(ctx, substream, params);
+ if (ret)
+ return ret;
+ }
+
+ return omap3pandora_common_hw_params(substream, params);
+}
+
+static int omap3pandora_capture_hw_params(struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params)
+{
+ struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+ struct snd_soc_dai *codec_dai = asoc_rtd_to_codec(rtd, 0);
+ struct device *dev = rtd->dev;
+ struct snd_soc_card *card = rtd->card;
+ struct omap3pandora_sound *ctx = snd_soc_card_get_drvdata(card);
+ int ret;
+
+ /* Set the codec system clock for DAC and ADC */
+ ret = snd_soc_dai_set_sysclk(codec_dai, 0, 26000000,
+ SND_SOC_CLOCK_IN);
+ if (ret < 0) {
+ dev_err(dev, "cannot set TWL4030 system clock: %d\n", ret);
+ return ret;
+ }
+
+ if (!ctx->capture_stream) {
+ ctx->capture_stream = substream;
+ ret = grab_sample_rate(ctx, substream, params);
+ if (ret)
+ return ret;
}
+ return omap3pandora_common_hw_params(substream, params);
+}
+
+static int omap3pandora_playback_hw_free(struct snd_pcm_substream *substream)
+{
+ struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+ struct snd_soc_card *card = rtd->card;
+ struct omap3pandora_sound *ctx = snd_soc_card_get_drvdata(card);
+
+ if (ctx->playback_stream)
+ release_sample_rate(ctx, substream);
+ ctx->playback_stream = NULL;
+
+ return 0;
+}
+
+static int omap3pandora_common_startup(struct snd_pcm_substream *substream)
+{
+ struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+ struct snd_soc_card *card = rtd->card;
+ struct omap3pandora_sound *ctx = snd_soc_card_get_drvdata(card);
+ unsigned int sample_rate = ctx->sample_rate;
+
+ if (!sample_rate)
+ return 0;
+
+ return constrain_sample_rate(substream, sample_rate);
+}
+
+static int omap3pandora_capture_hw_free(struct snd_pcm_substream *substream)
+{
+ struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+ struct snd_soc_card *card = rtd->card;
+ struct omap3pandora_sound *ctx = snd_soc_card_get_drvdata(card);
+
+ if (ctx->capture_stream)
+ release_sample_rate(ctx, substream);
+ ctx->capture_stream = NULL;
+
return 0;
}
static int omap3pandora_hp_event(struct snd_soc_dapm_widget *w,
struct snd_kcontrol *k, int event)
{
- if (SND_SOC_DAPM_EVENT_ON(event))
- gpio_set_value(OMAP3_PANDORA_AMP_POWER_GPIO, 1);
- else
- gpio_set_value(OMAP3_PANDORA_AMP_POWER_GPIO, 0);
+ struct snd_soc_card *card = w->dapm->card;
+ struct device *dev = card->dev;
+ struct omap3pandora_sound *ctx =
+ snd_soc_card_get_drvdata(card);
+ int ret;
+
+ if (SND_SOC_DAPM_EVENT_ON(event)) {
+ ret = regulator_enable(ctx->amp_regulator);
+ if (ret) {
+ dev_err(dev, "error enabling amplifier regulator: %d\n", ret);
+ return ret;
+ }
+
+ gpio_set_value(ctx->amp_gpio, 1);
+ } else {
+ gpio_set_value(ctx->amp_gpio, 0);
+
+ ret = regulator_disable(ctx->amp_regulator);
+ if (ret) {
+ dev_err(dev, "error disabling amplifier regulator: %d\n", ret);
+ return ret;
+ }
+ }
return 0;
}
@@ -108,9 +289,6 @@ static int omap3pandora_hp_event(struct snd_soc_dapm_widget *w,
* |P| <--- TWL4030 <--------- Line In and MICs
*/
static const struct snd_soc_dapm_widget omap3pandora_dapm_widgets[] = {
- SND_SOC_DAPM_DAC_E("PCM DAC", "HiFi Playback", SND_SOC_NOPM,
- 0, 0, omap3pandora_dac_event,
- SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_PRE_PMD),
SND_SOC_DAPM_PGA_E("Headphone Amplifier", SND_SOC_NOPM,
0, 0, NULL, 0, omap3pandora_hp_event,
SND_SOC_DAPM_POST_PMU | SND_SOC_DAPM_PRE_PMD),
@@ -123,9 +301,15 @@ static const struct snd_soc_dapm_widget omap3pandora_dapm_widgets[] = {
};
static const struct snd_soc_dapm_route omap3pandora_map[] = {
- {"PCM DAC", NULL, "APLL Enable"},
- {"Headphone Amplifier", NULL, "PCM DAC"},
- {"Line Out", NULL, "PCM DAC"},
+ /*
+ * The APLL signal produced by the TWL4030 is routed to the PCM1773 (in
+ * addition to supplying the clock for the McBSPs) so we need to make
+ * sure that APLL gets enabled before the PCM1773 begins operation.
+ */
+ {"PCM1773 DAC", NULL, "APLL Enable"},
+
+ {"Headphone Amplifier", NULL, "PCM1773 DAC"},
+ {"Line Out", NULL, "PCM1773 DAC"},
{"Headphone Jack", NULL, "Headphone Amplifier"},
{"AUXL", NULL, "Line In"},
@@ -170,15 +354,23 @@ static int omap3pandora_in_init(struct snd_soc_pcm_runtime *rtd)
return 0;
}
-static const struct snd_soc_ops omap3pandora_ops = {
- .hw_params = omap3pandora_hw_params,
+static const struct snd_soc_ops omap3pandora_playback_ops = {
+ .startup = omap3pandora_common_startup,
+ .hw_params = omap3pandora_playback_hw_params,
+ .hw_free = omap3pandora_playback_hw_free,
+};
+
+static const struct snd_soc_ops omap3pandora_capture_ops = {
+ .startup = omap3pandora_common_startup,
+ .hw_params = omap3pandora_capture_hw_params,
+ .hw_free = omap3pandora_capture_hw_free,
};
/* Digital audio interface glue - connects codec <--> CPU */
#if IS_BUILTIN(CONFIG_SND_SOC_OMAP3_PANDORA)
SND_SOC_DAILINK_DEFS(out,
DAILINK_COMP_ARRAY(COMP_CPU("omap-mcbsp.2")),
- DAILINK_COMP_ARRAY(COMP_CODEC("twl4030-codec", "twl4030-hifi")),
+ DAILINK_COMP_ARRAY(COMP_CODEC("pcm1773-codec", "pcm1773-hifi")),
DAILINK_COMP_ARRAY(COMP_PLATFORM("omap-mcbsp.2")));
SND_SOC_DAILINK_DEFS(in,
@@ -188,7 +380,7 @@ SND_SOC_DAILINK_DEFS(in,
#else /* IS_BUILTIN(CONFIG_SND_SOC_OMAP3_PANDORA) */
SND_SOC_DAILINK_DEFS(out,
DAILINK_COMP_ARRAY(COMP_CPU("49022000.mcbsp")),
- DAILINK_COMP_ARRAY(COMP_CODEC("twl4030-codec", "twl4030-hifi")),
+ DAILINK_COMP_ARRAY(COMP_CODEC("pcm1773-codec", "pcm1773-hifi")),
DAILINK_COMP_ARRAY(COMP_PLATFORM("49022000.mcbsp")));
SND_SOC_DAILINK_DEFS(in,
@@ -203,16 +395,18 @@ static struct snd_soc_dai_link omap3pandora_dai[] = {
.stream_name = "HiFi Out",
.dai_fmt = SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_NB_NF |
SND_SOC_DAIFMT_CBS_CFS,
- .ops = &omap3pandora_ops,
+ .ops = &omap3pandora_playback_ops,
.init = omap3pandora_out_init,
+ .playback_only = 1,
SND_SOC_DAILINK_REG(out),
}, {
.name = "TWL4030",
.stream_name = "Line/Mic In",
.dai_fmt = SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_NB_NF |
SND_SOC_DAIFMT_CBS_CFS,
- .ops = &omap3pandora_ops,
+ .ops = &omap3pandora_capture_ops,
.init = omap3pandora_in_init,
+ .capture_only = 1,
SND_SOC_DAILINK_REG(in),
}
};
@@ -228,92 +422,120 @@ static struct snd_soc_card snd_soc_card_omap3pandora = {
.num_dapm_widgets = ARRAY_SIZE(omap3pandora_dapm_widgets),
.dapm_routes = omap3pandora_map,
.num_dapm_routes = ARRAY_SIZE(omap3pandora_map),
+ .owner = THIS_MODULE,
};
-static struct platform_device *omap3pandora_snd_device;
-
-static int __init omap3pandora_soc_init(void)
+static int omap3pandora_probe(struct platform_device *pdev)
{
int ret;
+ struct device *dev = &pdev->dev;
+ struct device_node *of_node = dev->of_node;
+ struct snd_soc_card *card = &snd_soc_card_omap3pandora;
+ struct omap3pandora_sound *ctx;
+ int amp_gpio;
+ struct regulator *reg;
+
+ if (!of_node) {
+ dev_err(dev, "No DT data present; cannot determine amplifier powerup GPIO\n");
+ return -EINVAL;
+ }
- if (!machine_is_omap3_pandora() &&
- !of_machine_is_compatible("openpandora,omap3-pandora-600mhz") &&
- !of_machine_is_compatible("openpandora,omap3-pandora-1ghz"))
- return -ENODEV;
-
- pr_info("OMAP3 Pandora SoC init\n");
-
- ret = gpio_request(OMAP3_PANDORA_DAC_POWER_GPIO, "dac_power");
- if (ret) {
- pr_err(PREFIX "Failed to get DAC power GPIO\n");
- return ret;
+ ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
+ if (!ctx) {
+ dev_dbg(dev, "cannot allocate space for runtime data\n");
+ return -ENOMEM;
}
+ ctx->amp_gpio = -1;
+ mutex_init(&ctx->sample_rate_lock);
- ret = gpio_direction_output(OMAP3_PANDORA_DAC_POWER_GPIO, 0);
- if (ret) {
- pr_err(PREFIX "Failed to set DAC power GPIO direction\n");
- goto fail0;
+ ret = of_get_named_gpio(of_node, AMP_GPIO_NAME, 0);
+ if (ret < 0) {
+ dev_err(dev, "cannot find GPIO named " AMP_GPIO_NAME " in device tree\n");
+ goto fail;
}
+ amp_gpio = ret;
- ret = gpio_request(OMAP3_PANDORA_AMP_POWER_GPIO, "amp_power");
+ ret = gpio_request(amp_gpio, "amplifier power");
if (ret) {
- pr_err(PREFIX "Failed to get amp power GPIO\n");
- goto fail0;
+ dev_err(dev, "Failed to request amplifier powerup GPIO %d: %d\n",
+ ctx->amp_gpio, ret);
+ goto fail;
}
+ ctx->amp_gpio = amp_gpio;
- ret = gpio_direction_output(OMAP3_PANDORA_AMP_POWER_GPIO, 0);
+ ret = gpio_direction_output(ctx->amp_gpio, 0);
if (ret) {
- pr_err(PREFIX "Failed to set amp power GPIO direction\n");
- goto fail1;
+ dev_err(dev, "Failed to set amplifier powerup GPIO direction: %d\n",
+ ret);
+ goto fail;
}
- omap3pandora_snd_device = platform_device_alloc("soc-audio", -1);
- if (omap3pandora_snd_device == NULL) {
- pr_err(PREFIX "Platform device allocation failed\n");
- ret = -ENOMEM;
- goto fail1;
+ reg = regulator_get(dev, "opnd,amp");
+ if (IS_ERR(reg)) {
+ ret = PTR_ERR(reg);
+ dev_err(dev, "Failed to request regulator for amplifier power: %d\n", ret);
+ goto fail;
}
+ ctx->amp_regulator = reg;
- platform_set_drvdata(omap3pandora_snd_device, &snd_soc_card_omap3pandora);
-
- ret = platform_device_add(omap3pandora_snd_device);
+ card->dev = dev;
+ ret = snd_soc_register_card(card);
if (ret) {
- pr_err(PREFIX "Unable to add platform device\n");
- goto fail2;
+ dev_err(dev, "Failed to register sound card: %d\n", ret);
+ goto fail;
}
- omap3pandora_dac_reg = regulator_get(&omap3pandora_snd_device->dev, "vcc");
- if (IS_ERR(omap3pandora_dac_reg)) {
- pr_err(PREFIX "Failed to get DAC regulator from %s: %ld\n",
- dev_name(&omap3pandora_snd_device->dev),
- PTR_ERR(omap3pandora_dac_reg));
- ret = PTR_ERR(omap3pandora_dac_reg);
- goto fail3;
- }
+ snd_soc_card_set_drvdata(card, ctx);
return 0;
-fail3:
- platform_device_del(omap3pandora_snd_device);
-fail2:
- platform_device_put(omap3pandora_snd_device);
-fail1:
- gpio_free(OMAP3_PANDORA_AMP_POWER_GPIO);
-fail0:
- gpio_free(OMAP3_PANDORA_DAC_POWER_GPIO);
+fail:
+ if (ctx) {
+ if (ctx->amp_gpio >= 0)
+ gpio_free(ctx->amp_gpio);
+ if (ctx->amp_regulator)
+ regulator_put(ctx->amp_regulator);
+ }
+
return ret;
}
-module_init(omap3pandora_soc_init);
-static void __exit omap3pandora_soc_exit(void)
+static int omap3pandora_remove(struct platform_device *pdev)
{
- regulator_put(omap3pandora_dac_reg);
- platform_device_unregister(omap3pandora_snd_device);
- gpio_free(OMAP3_PANDORA_AMP_POWER_GPIO);
- gpio_free(OMAP3_PANDORA_DAC_POWER_GPIO);
+ struct snd_soc_card *card = platform_get_drvdata(pdev);
+ struct omap3pandora_sound *ctx = snd_soc_card_get_drvdata(card);
+
+ snd_soc_unregister_card(card);
+
+ if (ctx->amp_gpio >= 0)
+ gpio_free(ctx->amp_gpio);
+
+ if (ctx->amp_regulator)
+ regulator_put(ctx->amp_regulator);
+
+ mutex_destroy(&ctx->sample_rate_lock);
+
+ return 0;
}
-module_exit(omap3pandora_soc_exit);
+
+static const struct of_device_id omap3pandora_of_match[] = {
+ { .compatible = "openpandora,omap3pandora-sound", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, omap3pandora_of_match);
+
+static struct platform_driver omap3pandora_driver = {
+ .driver = {
+ .name = "omap3pandora-sound",
+ .of_match_table = omap3pandora_of_match,
+ },
+ .probe = omap3pandora_probe,
+ .remove = omap3pandora_remove,
+};
+
+module_platform_driver(omap3pandora_driver);
MODULE_AUTHOR("Grazvydas Ignotas <notasas at gmail.com>");
MODULE_DESCRIPTION("ALSA SoC OMAP3 Pandora");
MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:omap3pandora-sound");
--
2.33.0
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