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-rw-r--r--sound/soc/meson/axg-tdm-formatter.c397
1 files changed, 397 insertions, 0 deletions
diff --git a/sound/soc/meson/axg-tdm-formatter.c b/sound/soc/meson/axg-tdm-formatter.c
new file mode 100644
index 000000000..63333a2b0
--- /dev/null
+++ b/sound/soc/meson/axg-tdm-formatter.c
@@ -0,0 +1,397 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+//
+// Copyright (c) 2018 BayLibre, SAS.
+// Author: Jerome Brunet <jbrunet@baylibre.com>
+
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+#include <sound/soc.h>
+
+#include "axg-tdm-formatter.h"
+
+struct axg_tdm_formatter {
+ struct list_head list;
+ struct axg_tdm_stream *stream;
+ const struct axg_tdm_formatter_driver *drv;
+ struct clk *pclk;
+ struct clk *sclk;
+ struct clk *lrclk;
+ struct clk *sclk_sel;
+ struct clk *lrclk_sel;
+ struct reset_control *reset;
+ bool enabled;
+ struct regmap *map;
+};
+
+int axg_tdm_formatter_set_channel_masks(struct regmap *map,
+ struct axg_tdm_stream *ts,
+ unsigned int offset)
+{
+ unsigned int ch = ts->channels;
+ u32 val[AXG_TDM_NUM_LANES];
+ int i, j, k;
+
+ /*
+ * We need to mimick the slot distribution used by the HW to keep the
+ * channel placement consistent regardless of the number of channel
+ * in the stream. This is why the odd algorithm below is used.
+ */
+ memset(val, 0, sizeof(*val) * AXG_TDM_NUM_LANES);
+
+ /*
+ * Distribute the channels of the stream over the available slots
+ * of each TDM lane. We need to go over the 32 slots ...
+ */
+ for (i = 0; (i < 32) && ch; i += 2) {
+ /* ... of all the lanes ... */
+ for (j = 0; j < AXG_TDM_NUM_LANES; j++) {
+ /* ... then distribute the channels in pairs */
+ for (k = 0; k < 2; k++) {
+ if ((BIT(i + k) & ts->mask[j]) && ch) {
+ val[j] |= BIT(i + k);
+ ch -= 1;
+ }
+ }
+ }
+ }
+
+ /*
+ * If we still have channel left at the end of the process, it means
+ * the stream has more channels than we can accommodate and we should
+ * have caught this earlier.
+ */
+ if (WARN_ON(ch != 0)) {
+ pr_err("channel mask error\n");
+ return -EINVAL;
+ }
+
+ for (i = 0; i < AXG_TDM_NUM_LANES; i++) {
+ regmap_write(map, offset, val[i]);
+ offset += regmap_get_reg_stride(map);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(axg_tdm_formatter_set_channel_masks);
+
+static int axg_tdm_formatter_enable(struct axg_tdm_formatter *formatter)
+{
+ struct axg_tdm_stream *ts = formatter->stream;
+ bool invert;
+ int ret;
+
+ /* Do nothing if the formatter is already enabled */
+ if (formatter->enabled)
+ return 0;
+
+ /*
+ * On the g12a (and possibly other SoCs), when a stream using
+ * multiple lanes is restarted, it will sometimes not start
+ * from the first lane, but randomly from another used one.
+ * The result is an unexpected and random channel shift.
+ *
+ * The hypothesis is that an HW counter is not properly reset
+ * and the formatter simply starts on the lane it stopped
+ * before. Unfortunately, there does not seems to be a way to
+ * reset this through the registers of the block.
+ *
+ * However, the g12a has indenpendent reset lines for each audio
+ * devices. Using this reset before each start solves the issue.
+ */
+ ret = reset_control_reset(formatter->reset);
+ if (ret)
+ return ret;
+
+ /*
+ * If sclk is inverted, it means the bit should latched on the
+ * rising edge which is what our HW expects. If not, we need to
+ * invert it before the formatter.
+ */
+ invert = axg_tdm_sclk_invert(ts->iface->fmt);
+ ret = clk_set_phase(formatter->sclk, invert ? 0 : 180);
+ if (ret)
+ return ret;
+
+ /* Setup the stream parameter in the formatter */
+ ret = formatter->drv->ops->prepare(formatter->map,
+ formatter->drv->quirks,
+ formatter->stream);
+ if (ret)
+ return ret;
+
+ /* Enable the signal clocks feeding the formatter */
+ ret = clk_prepare_enable(formatter->sclk);
+ if (ret)
+ return ret;
+
+ ret = clk_prepare_enable(formatter->lrclk);
+ if (ret) {
+ clk_disable_unprepare(formatter->sclk);
+ return ret;
+ }
+
+ /* Finally, actually enable the formatter */
+ formatter->drv->ops->enable(formatter->map);
+ formatter->enabled = true;
+
+ return 0;
+}
+
+static void axg_tdm_formatter_disable(struct axg_tdm_formatter *formatter)
+{
+ /* Do nothing if the formatter is already disabled */
+ if (!formatter->enabled)
+ return;
+
+ formatter->drv->ops->disable(formatter->map);
+ clk_disable_unprepare(formatter->lrclk);
+ clk_disable_unprepare(formatter->sclk);
+ formatter->enabled = false;
+}
+
+static int axg_tdm_formatter_attach(struct axg_tdm_formatter *formatter)
+{
+ struct axg_tdm_stream *ts = formatter->stream;
+ int ret = 0;
+
+ mutex_lock(&ts->lock);
+
+ /* Catch up if the stream is already running when we attach */
+ if (ts->ready) {
+ ret = axg_tdm_formatter_enable(formatter);
+ if (ret) {
+ pr_err("failed to enable formatter\n");
+ goto out;
+ }
+ }
+
+ list_add_tail(&formatter->list, &ts->formatter_list);
+out:
+ mutex_unlock(&ts->lock);
+ return ret;
+}
+
+static void axg_tdm_formatter_dettach(struct axg_tdm_formatter *formatter)
+{
+ struct axg_tdm_stream *ts = formatter->stream;
+
+ mutex_lock(&ts->lock);
+ list_del(&formatter->list);
+ mutex_unlock(&ts->lock);
+
+ axg_tdm_formatter_disable(formatter);
+}
+
+static int axg_tdm_formatter_power_up(struct axg_tdm_formatter *formatter,
+ struct snd_soc_dapm_widget *w)
+{
+ struct axg_tdm_stream *ts = formatter->drv->ops->get_stream(w);
+ int ret;
+
+ /*
+ * If we don't get a stream at this stage, it would mean that the
+ * widget is powering up but is not attached to any backend DAI.
+ * It should not happen, ever !
+ */
+ if (WARN_ON(!ts))
+ return -ENODEV;
+
+ /* Clock our device */
+ ret = clk_prepare_enable(formatter->pclk);
+ if (ret)
+ return ret;
+
+ /* Reparent the bit clock to the TDM interface */
+ ret = clk_set_parent(formatter->sclk_sel, ts->iface->sclk);
+ if (ret)
+ goto disable_pclk;
+
+ /* Reparent the sample clock to the TDM interface */
+ ret = clk_set_parent(formatter->lrclk_sel, ts->iface->lrclk);
+ if (ret)
+ goto disable_pclk;
+
+ formatter->stream = ts;
+ ret = axg_tdm_formatter_attach(formatter);
+ if (ret)
+ goto disable_pclk;
+
+ return 0;
+
+disable_pclk:
+ clk_disable_unprepare(formatter->pclk);
+ return ret;
+}
+
+static void axg_tdm_formatter_power_down(struct axg_tdm_formatter *formatter)
+{
+ axg_tdm_formatter_dettach(formatter);
+ clk_disable_unprepare(formatter->pclk);
+ formatter->stream = NULL;
+}
+
+int axg_tdm_formatter_event(struct snd_soc_dapm_widget *w,
+ struct snd_kcontrol *control,
+ int event)
+{
+ struct snd_soc_component *c = snd_soc_dapm_to_component(w->dapm);
+ struct axg_tdm_formatter *formatter = snd_soc_component_get_drvdata(c);
+ int ret = 0;
+
+ switch (event) {
+ case SND_SOC_DAPM_PRE_PMU:
+ ret = axg_tdm_formatter_power_up(formatter, w);
+ break;
+
+ case SND_SOC_DAPM_PRE_PMD:
+ axg_tdm_formatter_power_down(formatter);
+ break;
+
+ default:
+ dev_err(c->dev, "Unexpected event %d\n", event);
+ return -EINVAL;
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(axg_tdm_formatter_event);
+
+int axg_tdm_formatter_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ const struct axg_tdm_formatter_driver *drv;
+ struct axg_tdm_formatter *formatter;
+ void __iomem *regs;
+
+ drv = of_device_get_match_data(dev);
+ if (!drv) {
+ dev_err(dev, "failed to match device\n");
+ return -ENODEV;
+ }
+
+ formatter = devm_kzalloc(dev, sizeof(*formatter), GFP_KERNEL);
+ if (!formatter)
+ return -ENOMEM;
+ platform_set_drvdata(pdev, formatter);
+ formatter->drv = drv;
+
+ regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(regs))
+ return PTR_ERR(regs);
+
+ formatter->map = devm_regmap_init_mmio(dev, regs, drv->regmap_cfg);
+ if (IS_ERR(formatter->map)) {
+ dev_err(dev, "failed to init regmap: %ld\n",
+ PTR_ERR(formatter->map));
+ return PTR_ERR(formatter->map);
+ }
+
+ /* Peripharal clock */
+ formatter->pclk = devm_clk_get(dev, "pclk");
+ if (IS_ERR(formatter->pclk))
+ return dev_err_probe(dev, PTR_ERR(formatter->pclk), "failed to get pclk\n");
+
+ /* Formatter bit clock */
+ formatter->sclk = devm_clk_get(dev, "sclk");
+ if (IS_ERR(formatter->sclk))
+ return dev_err_probe(dev, PTR_ERR(formatter->sclk), "failed to get sclk\n");
+
+ /* Formatter sample clock */
+ formatter->lrclk = devm_clk_get(dev, "lrclk");
+ if (IS_ERR(formatter->lrclk))
+ return dev_err_probe(dev, PTR_ERR(formatter->lrclk), "failed to get lrclk\n");
+
+ /* Formatter bit clock input multiplexer */
+ formatter->sclk_sel = devm_clk_get(dev, "sclk_sel");
+ if (IS_ERR(formatter->sclk_sel))
+ return dev_err_probe(dev, PTR_ERR(formatter->sclk_sel), "failed to get sclk_sel\n");
+
+ /* Formatter sample clock input multiplexer */
+ formatter->lrclk_sel = devm_clk_get(dev, "lrclk_sel");
+ if (IS_ERR(formatter->lrclk_sel))
+ return dev_err_probe(dev, PTR_ERR(formatter->lrclk_sel),
+ "failed to get lrclk_sel\n");
+
+ /* Formatter dedicated reset line */
+ formatter->reset = devm_reset_control_get_optional_exclusive(dev, NULL);
+ if (IS_ERR(formatter->reset))
+ return dev_err_probe(dev, PTR_ERR(formatter->reset), "failed to get reset\n");
+
+ return devm_snd_soc_register_component(dev, drv->component_drv,
+ NULL, 0);
+}
+EXPORT_SYMBOL_GPL(axg_tdm_formatter_probe);
+
+int axg_tdm_stream_start(struct axg_tdm_stream *ts)
+{
+ struct axg_tdm_formatter *formatter;
+ int ret = 0;
+
+ mutex_lock(&ts->lock);
+ ts->ready = true;
+
+ /* Start all the formatters attached to the stream */
+ list_for_each_entry(formatter, &ts->formatter_list, list) {
+ ret = axg_tdm_formatter_enable(formatter);
+ if (ret) {
+ pr_err("failed to start tdm stream\n");
+ goto out;
+ }
+ }
+
+out:
+ mutex_unlock(&ts->lock);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(axg_tdm_stream_start);
+
+void axg_tdm_stream_stop(struct axg_tdm_stream *ts)
+{
+ struct axg_tdm_formatter *formatter;
+
+ mutex_lock(&ts->lock);
+ ts->ready = false;
+
+ /* Stop all the formatters attached to the stream */
+ list_for_each_entry(formatter, &ts->formatter_list, list) {
+ axg_tdm_formatter_disable(formatter);
+ }
+
+ mutex_unlock(&ts->lock);
+}
+EXPORT_SYMBOL_GPL(axg_tdm_stream_stop);
+
+struct axg_tdm_stream *axg_tdm_stream_alloc(struct axg_tdm_iface *iface)
+{
+ struct axg_tdm_stream *ts;
+
+ ts = kzalloc(sizeof(*ts), GFP_KERNEL);
+ if (ts) {
+ INIT_LIST_HEAD(&ts->formatter_list);
+ mutex_init(&ts->lock);
+ ts->iface = iface;
+ }
+
+ return ts;
+}
+EXPORT_SYMBOL_GPL(axg_tdm_stream_alloc);
+
+void axg_tdm_stream_free(struct axg_tdm_stream *ts)
+{
+ /*
+ * If the list is not empty, it would mean that one of the formatter
+ * widget is still powered and attached to the interface while we
+ * are removing the TDM DAI. It should not be possible
+ */
+ WARN_ON(!list_empty(&ts->formatter_list));
+ mutex_destroy(&ts->lock);
+ kfree(ts);
+}
+EXPORT_SYMBOL_GPL(axg_tdm_stream_free);
+
+MODULE_DESCRIPTION("Amlogic AXG TDM formatter driver");
+MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
+MODULE_LICENSE("GPL v2");