From a40e693c7f5ee3a1a7d1f6aef63c5dadbec64e10 Mon Sep 17 00:00:00 2001 From: Jeeja KP Date: Thu, 9 Jul 2015 15:20:08 +0530 Subject: [PATCH] ASoC: Intel: Add Skylake HDA platform driver This patch starts to add the Skylake HDA platform driver by defining SoC CPU dais, DMA driver ops and implements ALSA operations Signed-off-by: Jeeja KP Signed-off-by: Subhransu S. Prusty Signed-off-by: Vinod Koul Signed-off-by: Mark Brown --- sound/soc/intel/skylake/skl-pcm.c | 586 ++++++++++++++++++++++++++++++ sound/soc/intel/skylake/skl.h | 71 ++++ 2 files changed, 657 insertions(+) create mode 100644 sound/soc/intel/skylake/skl-pcm.c create mode 100644 sound/soc/intel/skylake/skl.h diff --git a/sound/soc/intel/skylake/skl-pcm.c b/sound/soc/intel/skylake/skl-pcm.c new file mode 100644 index 000000000000..c171def2fcc9 --- /dev/null +++ b/sound/soc/intel/skylake/skl-pcm.c @@ -0,0 +1,586 @@ +/* + * skl-pcm.c -ASoC HDA Platform driver file implementing PCM functionality + * + * Copyright (C) 2014-2015 Intel Corp + * Author: Jeeja KP + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + */ + +#include +#include +#include +#include +#include "skl.h" + +#define HDA_MONO 1 +#define HDA_STEREO 2 + +static struct snd_pcm_hardware azx_pcm_hw = { + .info = (SNDRV_PCM_INFO_MMAP | + SNDRV_PCM_INFO_INTERLEAVED | + SNDRV_PCM_INFO_BLOCK_TRANSFER | + SNDRV_PCM_INFO_MMAP_VALID | + SNDRV_PCM_INFO_PAUSE | + SNDRV_PCM_INFO_SYNC_START | + SNDRV_PCM_INFO_HAS_WALL_CLOCK | /* legacy */ + SNDRV_PCM_INFO_HAS_LINK_ATIME | + SNDRV_PCM_INFO_NO_PERIOD_WAKEUP), + .formats = SNDRV_PCM_FMTBIT_S16_LE, + .rates = SNDRV_PCM_RATE_48000, + .rate_min = 48000, + .rate_max = 48000, + .channels_min = 2, + .channels_max = 2, + .buffer_bytes_max = AZX_MAX_BUF_SIZE, + .period_bytes_min = 128, + .period_bytes_max = AZX_MAX_BUF_SIZE / 2, + .periods_min = 2, + .periods_max = AZX_MAX_FRAG, + .fifo_size = 0, +}; + +static inline +struct hdac_ext_stream *get_hdac_ext_stream(struct snd_pcm_substream *substream) +{ + return substream->runtime->private_data; +} + +static struct hdac_ext_bus *get_bus_ctx(struct snd_pcm_substream *substream) +{ + struct hdac_ext_stream *stream = get_hdac_ext_stream(substream); + struct hdac_stream *hstream = hdac_stream(stream); + struct hdac_bus *bus = hstream->bus; + + return hbus_to_ebus(bus); +} + +static int skl_substream_alloc_pages(struct hdac_ext_bus *ebus, + struct snd_pcm_substream *substream, + size_t size) +{ + struct hdac_ext_stream *stream = get_hdac_ext_stream(substream); + + hdac_stream(stream)->bufsize = 0; + hdac_stream(stream)->period_bytes = 0; + hdac_stream(stream)->format_val = 0; + + return snd_pcm_lib_malloc_pages(substream, size); +} + +static int skl_substream_free_pages(struct hdac_bus *bus, + struct snd_pcm_substream *substream) +{ + return snd_pcm_lib_free_pages(substream); +} + +static void skl_set_pcm_constrains(struct hdac_ext_bus *ebus, + struct snd_pcm_runtime *runtime) +{ + snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS); + + /* avoid wrap-around with wall-clock */ + snd_pcm_hw_constraint_minmax(runtime, SNDRV_PCM_HW_PARAM_BUFFER_TIME, + 20, 178000000); +} + +static int skl_pcm_open(struct snd_pcm_substream *substream, + struct snd_soc_dai *dai) +{ + struct hdac_ext_bus *ebus = dev_get_drvdata(dai->dev); + struct hdac_ext_stream *stream; + struct snd_pcm_runtime *runtime = substream->runtime; + struct skl_dma_params *dma_params; + int ret; + + dev_dbg(dai->dev, "%s: %s\n", __func__, dai->name); + ret = pm_runtime_get_sync(dai->dev); + if (ret) + return ret; + + stream = snd_hdac_ext_stream_assign(ebus, substream, + HDAC_EXT_STREAM_TYPE_COUPLED); + if (stream == NULL) + return -EBUSY; + + skl_set_pcm_constrains(ebus, runtime); + + /* + * disable WALLCLOCK timestamps for capture streams + * until we figure out how to handle digital inputs + */ + if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) { + runtime->hw.info &= ~SNDRV_PCM_INFO_HAS_WALL_CLOCK; /* legacy */ + runtime->hw.info &= ~SNDRV_PCM_INFO_HAS_LINK_ATIME; + } + + runtime->private_data = stream; + + dma_params = kzalloc(sizeof(*dma_params), GFP_KERNEL); + if (!dma_params) + return -ENOMEM; + + dma_params->stream_tag = hdac_stream(stream)->stream_tag; + snd_soc_dai_set_dma_data(dai, substream, dma_params); + + dev_dbg(dai->dev, "stream tag set in dma params=%d\n", + dma_params->stream_tag); + snd_pcm_set_sync(substream); + + return 0; +} + +static int skl_get_format(struct snd_pcm_substream *substream, + struct snd_soc_dai *dai) +{ + struct snd_soc_pcm_runtime *rtd = snd_pcm_substream_chip(substream); + struct skl_dma_params *dma_params; + int format_val = 0; + struct snd_soc_dai *codec_dai = rtd->codec_dai; + + dma_params = snd_soc_dai_get_dma_data(codec_dai, substream); + if (dma_params) + format_val = dma_params->format; + + return format_val; +} + +static int skl_pcm_prepare(struct snd_pcm_substream *substream, + struct snd_soc_dai *dai) +{ + struct hdac_ext_stream *stream = get_hdac_ext_stream(substream); + unsigned int format_val; + int err; + + dev_dbg(dai->dev, "%s: %s\n", __func__, dai->name); + if (hdac_stream(stream)->prepared) { + dev_dbg(dai->dev, "already stream is prepared - returning\n"); + return 0; + } + + format_val = skl_get_format(substream, dai); + dev_dbg(dai->dev, "stream_tag=%d formatvalue=%d\n", + hdac_stream(stream)->stream_tag, format_val); + snd_hdac_stream_reset(hdac_stream(stream)); + + err = snd_hdac_stream_set_params(hdac_stream(stream), format_val); + if (err < 0) + return err; + + err = snd_hdac_stream_setup(hdac_stream(stream)); + if (err < 0) + return err; + + hdac_stream(stream)->prepared = 1; + + return err; +} + +static int skl_pcm_hw_params(struct snd_pcm_substream *substream, + struct snd_pcm_hw_params *params, + struct snd_soc_dai *dai) +{ + struct hdac_ext_bus *ebus = dev_get_drvdata(dai->dev); + struct snd_pcm_runtime *runtime = substream->runtime; + int ret; + + dev_dbg(dai->dev, "%s: %s\n", __func__, dai->name); + ret = skl_substream_alloc_pages(ebus, substream, + params_buffer_bytes(params)); + if (ret < 0) + return ret; + + dev_dbg(dai->dev, "format_val, rate=%d, ch=%d, format=%d\n", + runtime->rate, runtime->channels, runtime->format); + + return 0; +} + +static void skl_pcm_close(struct snd_pcm_substream *substream, + struct snd_soc_dai *dai) +{ + struct hdac_ext_stream *stream = get_hdac_ext_stream(substream); + struct skl_dma_params *dma_params = NULL; + + dev_dbg(dai->dev, "%s: %s\n", __func__, dai->name); + snd_hdac_ext_stream_release(stream, HDAC_EXT_STREAM_TYPE_COUPLED); + + dma_params = snd_soc_dai_get_dma_data(dai, substream); + /* + * now we should set this to NULL as we are freeing by the + * dma_params + */ + snd_soc_dai_set_dma_data(dai, substream, NULL); + + pm_runtime_mark_last_busy(dai->dev); + pm_runtime_put_autosuspend(dai->dev); + kfree(dma_params); +} + +static int skl_pcm_hw_free(struct snd_pcm_substream *substream, + struct snd_soc_dai *dai) +{ + struct hdac_ext_bus *ebus = dev_get_drvdata(dai->dev); + struct hdac_ext_stream *stream = get_hdac_ext_stream(substream); + + dev_dbg(dai->dev, "%s: %s\n", __func__, dai->name); + + snd_hdac_stream_cleanup(hdac_stream(stream)); + hdac_stream(stream)->prepared = 0; + + return skl_substream_free_pages(ebus_to_hbus(ebus), substream); +} + +static struct snd_soc_dai_ops skl_pcm_dai_ops = { + .startup = skl_pcm_open, + .shutdown = skl_pcm_close, + .prepare = skl_pcm_prepare, + .hw_params = skl_pcm_hw_params, + .hw_free = skl_pcm_hw_free, +}; + +static struct snd_soc_dai_driver skl_platform_dai[] = { +{ + .name = "System Pin", + .ops = &skl_pcm_dai_ops, + .playback = { + .stream_name = "System Playback", + .channels_min = HDA_MONO, + .channels_max = HDA_STEREO, + .rates = SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_16000 | SNDRV_PCM_RATE_8000, + .formats = SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_LE, + }, + .capture = { + .stream_name = "System Capture", + .channels_min = HDA_MONO, + .channels_max = HDA_STEREO, + .rates = SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_16000, + .formats = SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_LE, + }, +}, +{ + .name = "Deepbuffer Pin", + .ops = &skl_pcm_dai_ops, + .playback = { + .stream_name = "Deepbuffer Playback", + .channels_min = HDA_STEREO, + .channels_max = HDA_STEREO, + .rates = SNDRV_PCM_RATE_48000, + .formats = SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_LE, + }, +}, +{ + .name = "LowLatency Pin", + .ops = &skl_pcm_dai_ops, + .playback = { + .stream_name = "Low Latency Playback", + .channels_min = HDA_STEREO, + .channels_max = HDA_STEREO, + .rates = SNDRV_PCM_RATE_48000, + .formats = SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_LE, + }, +}, +}; + +static int skl_platform_open(struct snd_pcm_substream *substream) +{ + struct snd_pcm_runtime *runtime; + struct snd_soc_pcm_runtime *rtd = substream->private_data; + struct snd_soc_dai_link *dai_link = rtd->dai_link; + + dev_dbg(rtd->cpu_dai->dev, "In %s:%s\n", __func__, + dai_link->cpu_dai_name); + + runtime = substream->runtime; + snd_soc_set_runtime_hwparams(substream, &azx_pcm_hw); + + return 0; +} + +static int skl_platform_pcm_trigger(struct snd_pcm_substream *substream, + int cmd) +{ + struct hdac_ext_bus *ebus = get_bus_ctx(substream); + struct hdac_bus *bus = ebus_to_hbus(ebus); + struct hdac_ext_stream *stream; + struct snd_pcm_substream *s; + bool start; + int sbits = 0; + unsigned long cookie; + struct hdac_stream *hstr; + + stream = get_hdac_ext_stream(substream); + hstr = hdac_stream(stream); + + dev_dbg(bus->dev, "In %s cmd=%d\n", __func__, cmd); + + if (!hstr->prepared) + return -EPIPE; + + switch (cmd) { + case SNDRV_PCM_TRIGGER_START: + case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: + case SNDRV_PCM_TRIGGER_RESUME: + start = true; + break; + + case SNDRV_PCM_TRIGGER_PAUSE_PUSH: + case SNDRV_PCM_TRIGGER_SUSPEND: + case SNDRV_PCM_TRIGGER_STOP: + start = false; + break; + + default: + return -EINVAL; + } + + snd_pcm_group_for_each_entry(s, substream) { + if (s->pcm->card != substream->pcm->card) + continue; + stream = get_hdac_ext_stream(s); + sbits |= 1 << hdac_stream(stream)->index; + snd_pcm_trigger_done(s, substream); + } + + spin_lock_irqsave(&bus->reg_lock, cookie); + + /* first, set SYNC bits of corresponding streams */ + snd_hdac_stream_sync_trigger(hstr, true, sbits, AZX_REG_SSYNC); + + snd_pcm_group_for_each_entry(s, substream) { + if (s->pcm->card != substream->pcm->card) + continue; + stream = get_hdac_ext_stream(s); + if (start) + snd_hdac_stream_start(hdac_stream(stream), true); + else + snd_hdac_stream_stop(hdac_stream(stream)); + } + spin_unlock_irqrestore(&bus->reg_lock, cookie); + + snd_hdac_stream_sync(hstr, start, sbits); + + spin_lock_irqsave(&bus->reg_lock, cookie); + + /* reset SYNC bits */ + snd_hdac_stream_sync_trigger(hstr, false, sbits, AZX_REG_SSYNC); + if (start) + snd_hdac_stream_timecounter_init(hstr, sbits); + spin_unlock_irqrestore(&bus->reg_lock, cookie); + + return 0; +} + +/* calculate runtime delay from LPIB */ +static int skl_get_delay_from_lpib(struct hdac_ext_bus *ebus, + struct hdac_ext_stream *sstream, + unsigned int pos) +{ + struct hdac_bus *bus = ebus_to_hbus(ebus); + struct hdac_stream *hstream = hdac_stream(sstream); + struct snd_pcm_substream *substream = hstream->substream; + int stream = substream->stream; + unsigned int lpib_pos = snd_hdac_stream_get_pos_lpib(hstream); + int delay; + + if (stream == SNDRV_PCM_STREAM_PLAYBACK) + delay = pos - lpib_pos; + else + delay = lpib_pos - pos; + + if (delay < 0) { + if (delay >= hstream->delay_negative_threshold) + delay = 0; + else + delay += hstream->bufsize; + } + + if (delay >= hstream->period_bytes) { + dev_info(bus->dev, + "Unstable LPIB (%d >= %d); disabling LPIB delay counting\n", + delay, hstream->period_bytes); + delay = 0; + } + + return bytes_to_frames(substream->runtime, delay); +} + +static unsigned int skl_get_position(struct hdac_ext_stream *hstream, + int codec_delay) +{ + struct hdac_stream *hstr = hdac_stream(hstream); + struct snd_pcm_substream *substream = hstr->substream; + struct hdac_ext_bus *ebus = get_bus_ctx(substream); + unsigned int pos; + int delay; + + /* use the position buffer as default */ + pos = snd_hdac_stream_get_pos_posbuf(hdac_stream(hstream)); + + if (pos >= hdac_stream(hstream)->bufsize) + pos = 0; + + if (substream->runtime) { + delay = skl_get_delay_from_lpib(ebus, hstream, pos) + + codec_delay; + substream->runtime->delay += delay; + } + + return pos; +} + +static snd_pcm_uframes_t skl_platform_pcm_pointer + (struct snd_pcm_substream *substream) +{ + struct hdac_ext_stream *hstream = get_hdac_ext_stream(substream); + + return bytes_to_frames(substream->runtime, + skl_get_position(hstream, 0)); +} + +static u64 skl_adjust_codec_delay(struct snd_pcm_substream *substream, + u64 nsec) +{ + struct snd_soc_pcm_runtime *rtd = snd_pcm_substream_chip(substream); + struct snd_soc_dai *codec_dai = rtd->codec_dai; + u64 codec_frames, codec_nsecs; + + if (!codec_dai->driver->ops->delay) + return nsec; + + codec_frames = codec_dai->driver->ops->delay(substream, codec_dai); + codec_nsecs = div_u64(codec_frames * 1000000000LL, + substream->runtime->rate); + + if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) + return nsec + codec_nsecs; + + return (nsec > codec_nsecs) ? nsec - codec_nsecs : 0; +} + +static int skl_get_time_info(struct snd_pcm_substream *substream, + struct timespec *system_ts, struct timespec *audio_ts, + struct snd_pcm_audio_tstamp_config *audio_tstamp_config, + struct snd_pcm_audio_tstamp_report *audio_tstamp_report) +{ + struct hdac_ext_stream *sstream = get_hdac_ext_stream(substream); + struct hdac_stream *hstr = hdac_stream(sstream); + u64 nsec; + + if ((substream->runtime->hw.info & SNDRV_PCM_INFO_HAS_LINK_ATIME) && + (audio_tstamp_config->type_requested == SNDRV_PCM_AUDIO_TSTAMP_TYPE_LINK)) { + + snd_pcm_gettime(substream->runtime, system_ts); + + nsec = timecounter_read(&hstr->tc); + nsec = div_u64(nsec, 3); /* can be optimized */ + if (audio_tstamp_config->report_delay) + nsec = skl_adjust_codec_delay(substream, nsec); + + *audio_ts = ns_to_timespec(nsec); + + audio_tstamp_report->actual_type = SNDRV_PCM_AUDIO_TSTAMP_TYPE_LINK; + audio_tstamp_report->accuracy_report = 1; /* rest of struct is valid */ + audio_tstamp_report->accuracy = 42; /* 24MHzWallClk == 42ns resolution */ + + } else { + audio_tstamp_report->actual_type = SNDRV_PCM_AUDIO_TSTAMP_TYPE_DEFAULT; + } + + return 0; +} + +static struct snd_pcm_ops skl_platform_ops = { + .open = skl_platform_open, + .ioctl = snd_pcm_lib_ioctl, + .trigger = skl_platform_pcm_trigger, + .pointer = skl_platform_pcm_pointer, + .get_time_info = skl_get_time_info, + .mmap = snd_pcm_lib_default_mmap, + .page = snd_pcm_sgbuf_ops_page, +}; + +static void skl_pcm_free(struct snd_pcm *pcm) +{ + snd_pcm_lib_preallocate_free_for_all(pcm); +} + +#define MAX_PREALLOC_SIZE (32 * 1024 * 1024) + +static int skl_pcm_new(struct snd_soc_pcm_runtime *rtd) +{ + struct snd_soc_dai *dai = rtd->cpu_dai; + struct hdac_ext_bus *ebus = dev_get_drvdata(dai->dev); + struct snd_pcm *pcm = rtd->pcm; + unsigned int size; + int retval = 0; + struct skl *skl = ebus_to_skl(ebus); + + if (dai->driver->playback.channels_min || + dai->driver->capture.channels_min) { + /* buffer pre-allocation */ + size = CONFIG_SND_HDA_PREALLOC_SIZE * 1024; + if (size > MAX_PREALLOC_SIZE) + size = MAX_PREALLOC_SIZE; + retval = snd_pcm_lib_preallocate_pages_for_all(pcm, + SNDRV_DMA_TYPE_DEV_SG, + snd_dma_pci_data(skl->pci), + size, MAX_PREALLOC_SIZE); + if (retval) { + dev_err(dai->dev, "dma buffer allocationf fail\n"); + return retval; + } + } + + return retval; +} + +static struct snd_soc_platform_driver skl_platform_drv = { + .ops = &skl_platform_ops, + .pcm_new = skl_pcm_new, + .pcm_free = skl_pcm_free, +}; + +static const struct snd_soc_component_driver skl_component = { + .name = "pcm", +}; + +int skl_platform_register(struct device *dev) +{ + int ret; + + ret = snd_soc_register_platform(dev, &skl_platform_drv); + if (ret) { + dev_err(dev, "soc platform registration failed %d\n", ret); + return ret; + } + ret = snd_soc_register_component(dev, &skl_component, + skl_platform_dai, + ARRAY_SIZE(skl_platform_dai)); + if (ret) { + dev_err(dev, "soc component registration failed %d\n", ret); + snd_soc_unregister_platform(dev); + } + + return ret; + +} + +int skl_platform_unregister(struct device *dev) +{ + snd_soc_unregister_component(dev); + snd_soc_unregister_platform(dev); + return 0; +} diff --git a/sound/soc/intel/skylake/skl.h b/sound/soc/intel/skylake/skl.h new file mode 100644 index 000000000000..cc0f3e263495 --- /dev/null +++ b/sound/soc/intel/skylake/skl.h @@ -0,0 +1,71 @@ +/* + * skl.h - HD Audio skylake defintions. + * + * Copyright (C) 2015 Intel Corp + * Author: Jeeja KP + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + */ + +#ifndef __SOUND_SOC_SKL_H +#define __SOUND_SOC_SKL_H + +#include +#include + +#define SKL_SUSPEND_DELAY 2000 + +/* Vendor Specific Registers */ +#define AZX_REG_VS_EM1 0x1000 +#define AZX_REG_VS_INRC 0x1004 +#define AZX_REG_VS_OUTRC 0x1008 +#define AZX_REG_VS_FIFOTRK 0x100C +#define AZX_REG_VS_FIFOTRK2 0x1010 +#define AZX_REG_VS_EM2 0x1030 +#define AZX_REG_VS_EM3L 0x1038 +#define AZX_REG_VS_EM3U 0x103C +#define AZX_REG_VS_EM4L 0x1040 +#define AZX_REG_VS_EM4U 0x1044 +#define AZX_REG_VS_LTRC 0x1048 +#define AZX_REG_VS_D0I3C 0x104A +#define AZX_REG_VS_PCE 0x104B +#define AZX_REG_VS_L2MAGC 0x1050 +#define AZX_REG_VS_L2LAHPT 0x1054 +#define AZX_REG_VS_SDXDPIB_XBASE 0x1084 +#define AZX_REG_VS_SDXDPIB_XINTERVAL 0x20 +#define AZX_REG_VS_SDXEFIFOS_XBASE 0x1094 +#define AZX_REG_VS_SDXEFIFOS_XINTERVAL 0x20 + +struct skl { + struct hdac_ext_bus ebus; + struct pci_dev *pci; + + unsigned int init_failed:1; /* delayed init failed */ + struct platform_device *dmic_dev; +}; + +#define skl_to_ebus(s) (&(s)->ebus) +#define ebus_to_skl(sbus) \ + container_of(sbus, struct skl, sbus) + +/* to pass dai dma data */ +struct skl_dma_params { + u32 format; + u8 stream_tag; +}; + +int skl_platform_unregister(struct device *dev); +int skl_platform_register(struct device *dev); + +#endif /* __SOUND_SOC_SKL_H */ -- 2.20.1