From bcba10e5c5da279fa57920ee1c08ee1dea84a4f6 Mon Sep 17 00:00:00 2001 From: escalator2015 Date: Tue, 24 May 2016 16:20:09 +0100 Subject: [PATCH] New driver for RRA DigiDAC1 soundcard using WM8741 + WM8804 --- arch/arm/boot/dts/overlays/Makefile | 1 + arch/arm/boot/dts/overlays/README | 6 + .../overlays/rra-digidac1-wm8741-audio-overlay.dts | 81 ++++ arch/arm/configs/bcm2709_defconfig | 1 + arch/arm/configs/bcmrpi_defconfig | 1 + sound/soc/bcm/Kconfig | 8 + sound/soc/bcm/Makefile | 2 + sound/soc/bcm/digidac1-soundcard.c | 422 +++++++++++++++++++++ 8 files changed, 522 insertions(+) create mode 100644 arch/arm/boot/dts/overlays/rra-digidac1-wm8741-audio-overlay.dts create mode 100644 sound/soc/bcm/digidac1-soundcard.c --- a/arch/arm/boot/dts/overlays/Makefile +++ b/arch/arm/boot/dts/overlays/Makefile @@ -67,6 +67,7 @@ dtbo-$(RPI_DT_OVERLAYS) += rpi-display.d dtbo-$(RPI_DT_OVERLAYS) += rpi-ft5406.dtbo dtbo-$(RPI_DT_OVERLAYS) += rpi-proto.dtbo dtbo-$(RPI_DT_OVERLAYS) += rpi-sense.dtbo +dtbo-$(RPI_DT_OVERLAYS) += rra-digidac1-wm8741-audio.dtbo dtbo-$(RPI_DT_OVERLAYS) += sdhost.dtbo dtbo-$(RPI_DT_OVERLAYS) += sdio.dtbo dtbo-$(RPI_DT_OVERLAYS) += sdio-1bit.dtbo --- a/arch/arm/boot/dts/overlays/README +++ b/arch/arm/boot/dts/overlays/README @@ -842,6 +842,12 @@ Load: dtoverlay=rpi-sense Params: +Name: rra-digidac1-wm8741-audio +Info: Configures the Red Rocks Audio DigiDAC1 soundcard +Load: dtoverlay=rra-digidac1-wm8741-audio +Params: + + Name: sdhost Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock. N.B. This overlay is designed for situations where the mmc driver is --- /dev/null +++ b/arch/arm/boot/dts/overlays/rra-digidac1-wm8741-audio-overlay.dts @@ -0,0 +1,81 @@ +// Definitions for RRA DigiDAC1 Audio card +/dts-v1/; +/plugin/; + +/ { + compatible = "brcm,bcm2708"; + + fragment@0 { + target-path = "/"; + __overlay__ { + aliases { + ldo0 = &ldo0; + ldo1 = &ldo1; + }; + }; + }; + + fragment@1 { + target-path = "/soc"; + __overlay__ { + + ldo1: ldo1 { + compatible = "regulator-fixed"; + regulator-name = "DC_5V"; + regulator-min-microvolt = <5000000>; + regulator-max-microvolt = <5000000>; + regulator-always-on; + }; + + ldo0: ldo0 { + compatible = "regulator-fixed"; + regulator-name = "DC_3V3"; + regulator-min-microvolt = <3300000>; + regulator-max-microvolt = <3300000>; + regulator-always-on; + }; + }; + }; + + fragment@2 { + target = <&i2s>; + __overlay__ { + status = "okay"; + }; + }; + + fragment@3 { + target = <&i2c1>; + __overlay__ { + #address-cells = <1>; + #size-cells = <0>; + status = "okay"; + + wm8804@3b { + #sound-dai-cells = <0>; + compatible = "wlf,wm8804"; + reg = <0x3b>; + status = "okay"; + PVDD-supply = <&ldo0>; + DVDD-supply = <&ldo0>; + }; + + wm8742: wm8741@1a { + compatible = "wlf,wm8741"; + reg = <0x1a>; + status = "okay"; + AVDD-supply = <&ldo1>; + DVDD-supply = <&ldo0>; + }; + }; + }; + + fragment@4 { + target = <&sound>; + __overlay__ { + compatible = "rra,digidac1-soundcard"; + i2s-controller = <&i2s>; + status = "okay"; + }; + }; +}; --- a/arch/arm/configs/bcm2709_defconfig +++ b/arch/arm/configs/bcm2709_defconfig @@ -866,6 +866,7 @@ CONFIG_SND_BCM2708_SOC_JUSTBOOM_DIGI=m CONFIG_SND_BCM2708_SOC_IQAUDIO_DAC=m CONFIG_SND_BCM2708_SOC_RASPIDAC3=m CONFIG_SND_AUDIOINJECTOR_PI_SOUNDCARD=m +CONFIG_SND_DIGIDAC1_SOUNDCARD=m CONFIG_SND_BCM2708_SOC_ADAU1977_ADC=m CONFIG_SND_SOC_ADAU1701=m CONFIG_SND_SOC_WM8804_I2C=m --- a/arch/arm/configs/bcmrpi_defconfig +++ b/arch/arm/configs/bcmrpi_defconfig @@ -858,6 +858,7 @@ CONFIG_SND_BCM2708_SOC_JUSTBOOM_DIGI=m CONFIG_SND_BCM2708_SOC_IQAUDIO_DAC=m CONFIG_SND_BCM2708_SOC_RASPIDAC3=m CONFIG_SND_AUDIOINJECTOR_PI_SOUNDCARD=m +CONFIG_SND_DIGIDAC1_SOUNDCARD=m CONFIG_SND_BCM2708_SOC_ADAU1977_ADC=m CONFIG_SND_SOC_ADAU1701=m CONFIG_SND_SOC_WM8804_I2C=m --- a/sound/soc/bcm/Kconfig +++ b/sound/soc/bcm/Kconfig @@ -92,3 +92,11 @@ config SND_AUDIOINJECTOR_PI_SOUNDCARD select SND_SOC_WM8731 help Say Y or M if you want to add support for audioinjector.net Pi Hat + +config SND_DIGIDAC1_SOUNDCARD + tristate "Support for Red Rocks Audio DigiDAC1" + depends on SND_BCM2708_SOC_I2S || SND_BCM2835_SOC_I2S + select SND_SOC_WM8804 + select SND_SOC_WM8741 + help + Say Y or M if you want to add support for Red Rocks Audio DigiDAC1 board. --- a/sound/soc/bcm/Makefile +++ b/sound/soc/bcm/Makefile @@ -16,6 +16,7 @@ snd-soc-rpi-proto-objs := rpi-proto.o snd-soc-iqaudio-dac-objs := iqaudio-dac.o snd-soc-raspidac3-objs := raspidac3.o snd-soc-audioinjector-pi-soundcard-objs := audioinjector-pi-soundcard.o +snd-soc-digidac1-soundcard-objs := digidac1-soundcard.o obj-$(CONFIG_SND_BCM2708_SOC_ADAU1977_ADC) += snd-soc-adau1977-adc.o obj-$(CONFIG_SND_BCM2708_SOC_HIFIBERRY_DAC) += snd-soc-hifiberry-dac.o @@ -29,4 +30,5 @@ obj-$(CONFIG_SND_BCM2708_SOC_RPI_PROTO) obj-$(CONFIG_SND_BCM2708_SOC_IQAUDIO_DAC) += snd-soc-iqaudio-dac.o obj-$(CONFIG_SND_BCM2708_SOC_RASPIDAC3) += snd-soc-raspidac3.o obj-$(CONFIG_SND_AUDIOINJECTOR_PI_SOUNDCARD) += snd-soc-audioinjector-pi-soundcard.o +obj-$(CONFIG_SND_DIGIDAC1_SOUNDCARD) += snd-soc-digidac1-soundcard.o --- /dev/null +++ b/sound/soc/bcm/digidac1-soundcard.c @@ -0,0 +1,422 @@ +/* + * ASoC Driver for RRA DigiDAC1 + * Copyright 2016 + * Author: José M. Tasende + * based on the HifiBerry DAC driver by Florian Meier + * and the Wolfson card driver by Nikesh Oswal, + * 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. + * + * 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 +#include +#include +#include +#include +#include +#include + +#include "../codecs/wm8804.h" +#include "../codecs/wm8741.h" + +#define WM8741_NUM_SUPPLIES 2 + +/* codec private data */ +struct wm8741_priv { + struct wm8741_platform_data pdata; + struct regmap *regmap; + struct regulator_bulk_data supplies[WM8741_NUM_SUPPLIES]; + unsigned int sysclk; + const struct snd_pcm_hw_constraint_list *sysclk_constraints; +}; + +static int samplerate = 44100; + +/* New Alsa Controls not exposed by original wm8741 codec driver */ +/* in actual driver the att. adjustment is wrong because */ +/* this DAC has a coarse attenuation register with 4dB steps */ +/* and a fine level register with 0.125dB steps */ +/* each register has 32 steps so combining both we have 1024 steps */ +/* of 0.125 dB. */ +/* The original level controls from driver are removed at startup */ +/* and replaced by the corrected ones. */ +/* The same wm8741 driver can be used for wm8741 and wm8742 devices */ + +static const DECLARE_TLV_DB_SCALE(dac_tlv_fine, 0, 13, 0); +static const DECLARE_TLV_DB_SCALE(dac_tlv_coarse, -12700, 400, 1); +static const char *w8741_dither[4] = {"Off", "RPDF", "TPDF", "HPDF"}; +static const char *w8741_filter[5] = { + "Type 1", "Type 2", "Type 3", "Type 4", "Type 5"}; +static const char *w8741_switch[2] = {"Off", "On"}; +static const struct soc_enum w8741_enum[] = { +SOC_ENUM_SINGLE(WM8741_MODE_CONTROL_2, 0, 4, w8741_dither),/* dithering type */ +SOC_ENUM_SINGLE(WM8741_FILTER_CONTROL, 0, 5, w8741_filter),/* filter type */ +SOC_ENUM_SINGLE(WM8741_FORMAT_CONTROL, 6, 2, w8741_switch),/* phase invert */ +SOC_ENUM_SINGLE(WM8741_VOLUME_CONTROL, 0, 2, w8741_switch),/* volume ramp */ +SOC_ENUM_SINGLE(WM8741_VOLUME_CONTROL, 3, 2, w8741_switch),/* soft mute */ +}; + +static const struct snd_kcontrol_new w8741_snd_controls_stereo[] = { +SOC_DOUBLE_R_TLV("DAC Fine Playback Volume", WM8741_DACLLSB_ATTENUATION, + WM8741_DACRLSB_ATTENUATION, 0, 31, 1, dac_tlv_fine), +SOC_DOUBLE_R_TLV("Digital Playback Volume", WM8741_DACLMSB_ATTENUATION, + WM8741_DACRMSB_ATTENUATION, 0, 31, 1, dac_tlv_coarse), +SOC_ENUM("DAC Dither", w8741_enum[0]), +SOC_ENUM("DAC Digital Filter", w8741_enum[1]), +SOC_ENUM("DAC Phase Invert", w8741_enum[2]), +SOC_ENUM("DAC Volume Ramp", w8741_enum[3]), +SOC_ENUM("DAC Soft Mute", w8741_enum[4]), +}; + +static const struct snd_kcontrol_new w8741_snd_controls_mono_left[] = { +SOC_SINGLE_TLV("DAC Fine Playback Volume", WM8741_DACLLSB_ATTENUATION, + 0, 31, 0, dac_tlv_fine), +SOC_SINGLE_TLV("Digital Playback Volume", WM8741_DACLMSB_ATTENUATION, + 0, 31, 1, dac_tlv_coarse), +SOC_ENUM("DAC Dither", w8741_enum[0]), +SOC_ENUM("DAC Digital Filter", w8741_enum[1]), +SOC_ENUM("DAC Phase Invert", w8741_enum[2]), +SOC_ENUM("DAC Volume Ramp", w8741_enum[3]), +SOC_ENUM("DAC Soft Mute", w8741_enum[4]), +}; + +static const struct snd_kcontrol_new w8741_snd_controls_mono_right[] = { +SOC_SINGLE_TLV("DAC Fine Playback Volume", WM8741_DACRLSB_ATTENUATION, + 0, 31, 0, dac_tlv_fine), +SOC_SINGLE_TLV("Digital Playback Volume", WM8741_DACRMSB_ATTENUATION, + 0, 31, 1, dac_tlv_coarse), +SOC_ENUM("DAC Dither", w8741_enum[0]), +SOC_ENUM("DAC Digital Filter", w8741_enum[1]), +SOC_ENUM("DAC Phase Invert", w8741_enum[2]), +SOC_ENUM("DAC Volume Ramp", w8741_enum[3]), +SOC_ENUM("DAC Soft Mute", w8741_enum[4]), +}; + +static int w8741_add_controls(struct snd_soc_codec *codec) +{ + struct wm8741_priv *wm8741 = snd_soc_codec_get_drvdata(codec); + + switch (wm8741->pdata.diff_mode) { + case WM8741_DIFF_MODE_STEREO: + case WM8741_DIFF_MODE_STEREO_REVERSED: + snd_soc_add_codec_controls(codec, + w8741_snd_controls_stereo, + ARRAY_SIZE(w8741_snd_controls_stereo)); + break; + case WM8741_DIFF_MODE_MONO_LEFT: + snd_soc_add_codec_controls(codec, + w8741_snd_controls_mono_left, + ARRAY_SIZE(w8741_snd_controls_mono_left)); + break; + case WM8741_DIFF_MODE_MONO_RIGHT: + snd_soc_add_codec_controls(codec, + w8741_snd_controls_mono_right, + ARRAY_SIZE(w8741_snd_controls_mono_right)); + break; + default: + return -EINVAL; + } + + return 0; +} + +static int digidac1_soundcard_init(struct snd_soc_pcm_runtime *rtd) +{ + struct snd_soc_codec *codec = rtd->codec; + struct snd_soc_card *card = rtd->card; + struct snd_soc_pcm_runtime *wm8741_rtd; + struct snd_soc_codec *wm8741_codec; + struct snd_card *sound_card = card->snd_card; + struct snd_kcontrol *kctl; + int ret; + + wm8741_rtd = snd_soc_get_pcm_runtime(card, card->dai_link[1].name); + if (!wm8741_rtd) { + dev_warn(card->dev, "digidac1_soundcard_init: couldn't get wm8741 rtd\n"); + return -EFAULT; + } + wm8741_codec = wm8741_rtd->codec; + ret = w8741_add_controls(wm8741_codec); + if (ret < 0) + dev_warn(card->dev, "Failed to add new wm8741 controls: %d\n", + ret); + + /* enable TX output */ + snd_soc_update_bits(codec, WM8804_PWRDN, 0x4, 0x0); + + kctl = snd_soc_card_get_kcontrol(card, + "Playback Volume"); + if (kctl) { + kctl->vd[0].access = SNDRV_CTL_ELEM_ACCESS_READWRITE; + snd_ctl_remove(sound_card, kctl); + } + kctl = snd_soc_card_get_kcontrol(card, + "Fine Playback Volume"); + if (kctl) { + kctl->vd[0].access = SNDRV_CTL_ELEM_ACCESS_READWRITE; + snd_ctl_remove(sound_card, kctl); + } + return 0; +} + +static int digidac1_soundcard_startup(struct snd_pcm_substream *substream) +{ + /* turn on wm8804 digital output */ + struct snd_soc_pcm_runtime *rtd = substream->private_data; + struct snd_soc_codec *codec = rtd->codec; + struct snd_soc_card *card = rtd->card; + struct snd_soc_pcm_runtime *wm8741_rtd; + struct snd_soc_codec *wm8741_codec; + + snd_soc_update_bits(codec, WM8804_PWRDN, 0x3c, 0x00); + wm8741_rtd = snd_soc_get_pcm_runtime(card, card->dai_link[1].name); + if (!wm8741_rtd) { + dev_warn(card->dev, "digidac1_soundcard_startup: couldn't get WM8741 rtd\n"); + return -EFAULT; + } + wm8741_codec = wm8741_rtd->codec; + + /* latch wm8741 level */ + snd_soc_update_bits(wm8741_codec, WM8741_DACLLSB_ATTENUATION, + WM8741_UPDATELL, WM8741_UPDATELL); + snd_soc_update_bits(wm8741_codec, WM8741_DACLMSB_ATTENUATION, + WM8741_UPDATELM, WM8741_UPDATELM); + snd_soc_update_bits(wm8741_codec, WM8741_DACRLSB_ATTENUATION, + WM8741_UPDATERL, WM8741_UPDATERL); + snd_soc_update_bits(wm8741_codec, WM8741_DACRMSB_ATTENUATION, + WM8741_UPDATERM, WM8741_UPDATERM); + + return 0; +} + +static void digidac1_soundcard_shutdown(struct snd_pcm_substream *substream) +{ + /* turn off wm8804 digital output */ + struct snd_soc_pcm_runtime *rtd = substream->private_data; + struct snd_soc_codec *codec = rtd->codec; + + snd_soc_update_bits(codec, WM8804_PWRDN, 0x3c, 0x3c); +} + +static int digidac1_soundcard_hw_params(struct snd_pcm_substream *substream, + struct snd_pcm_hw_params *params) +{ + struct snd_soc_pcm_runtime *rtd = substream->private_data; + struct snd_soc_dai *codec_dai = rtd->codec_dai; + struct snd_soc_codec *codec = rtd->codec; + struct snd_soc_dai *cpu_dai = rtd->cpu_dai; + struct snd_soc_card *card = rtd->card; + struct snd_soc_pcm_runtime *wm8741_rtd; + struct snd_soc_codec *wm8741_codec; + + int sysclk = 27000000; + long mclk_freq = 0; + int mclk_div = 1; + int sampling_freq = 1; + int ret; + + wm8741_rtd = snd_soc_get_pcm_runtime(card, card->dai_link[1].name); + if (!wm8741_rtd) { + dev_warn(card->dev, "digidac1_soundcard_hw_params: couldn't get WM8741 rtd\n"); + return -EFAULT; + } + wm8741_codec = wm8741_rtd->codec; + samplerate = params_rate(params); + + if (samplerate <= 96000) { + mclk_freq = samplerate*256; + mclk_div = WM8804_MCLKDIV_256FS; + } else { + mclk_freq = samplerate*128; + mclk_div = WM8804_MCLKDIV_128FS; + } + + switch (samplerate) { + case 32000: + sampling_freq = 0x03; + break; + case 44100: + sampling_freq = 0x00; + break; + case 48000: + sampling_freq = 0x02; + break; + case 88200: + sampling_freq = 0x08; + break; + case 96000: + sampling_freq = 0x0a; + break; + case 176400: + sampling_freq = 0x0c; + break; + case 192000: + sampling_freq = 0x0e; + break; + default: + dev_err(codec->dev, + "Failed to set WM8804 SYSCLK, unsupported samplerate %d\n", + samplerate); + } + + snd_soc_dai_set_clkdiv(codec_dai, WM8804_MCLK_DIV, mclk_div); + snd_soc_dai_set_pll(codec_dai, 0, 0, sysclk, mclk_freq); + + ret = snd_soc_dai_set_sysclk(codec_dai, WM8804_TX_CLKSRC_PLL, + sysclk, SND_SOC_CLOCK_OUT); + if (ret < 0) { + dev_err(codec->dev, + "Failed to set WM8804 SYSCLK: %d\n", ret); + return ret; + } + /* Enable wm8804 TX output */ + snd_soc_update_bits(codec, WM8804_PWRDN, 0x4, 0x0); + + /* wm8804 Power on */ + snd_soc_update_bits(codec, WM8804_PWRDN, 0x9, 0); + + /* wm8804 set sampling frequency status bits */ + snd_soc_update_bits(codec, WM8804_SPDTX4, 0x0f, sampling_freq); + + /* Now update wm8741 registers for the correct oversampling */ + if (samplerate <= 48000) + snd_soc_update_bits(wm8741_codec, WM8741_MODE_CONTROL_1, + WM8741_OSR_MASK, 0x00); + else if (samplerate <= 96000) + snd_soc_update_bits(wm8741_codec, WM8741_MODE_CONTROL_1, + WM8741_OSR_MASK, 0x20); + else + snd_soc_update_bits(wm8741_codec, WM8741_MODE_CONTROL_1, + WM8741_OSR_MASK, 0x40); + + /* wm8741 bit size */ + switch (params_width(params)) { + case 16: + snd_soc_update_bits(wm8741_codec, WM8741_FORMAT_CONTROL, + WM8741_IWL_MASK, 0x00); + break; + case 20: + snd_soc_update_bits(wm8741_codec, WM8741_FORMAT_CONTROL, + WM8741_IWL_MASK, 0x01); + break; + case 24: + snd_soc_update_bits(wm8741_codec, WM8741_FORMAT_CONTROL, + WM8741_IWL_MASK, 0x02); + break; + case 32: + snd_soc_update_bits(wm8741_codec, WM8741_FORMAT_CONTROL, + WM8741_IWL_MASK, 0x03); + break; + default: + dev_dbg(codec->dev, "wm8741_hw_params: Unsupported bit size param = %d", + params_width(params)); + return -EINVAL; + } + + return snd_soc_dai_set_bclk_ratio(cpu_dai, 64); +} +/* machine stream operations */ +static struct snd_soc_ops digidac1_soundcard_ops = { + .hw_params = digidac1_soundcard_hw_params, + .startup = digidac1_soundcard_startup, + .shutdown = digidac1_soundcard_shutdown, +}; + +static struct snd_soc_dai_link digidac1_soundcard_dai[] = { + { + .name = "RRA DigiDAC1", + .stream_name = "RRA DigiDAC1 HiFi", + .cpu_dai_name = "bcm2708-i2s.0", + .codec_dai_name = "wm8804-spdif", + .platform_name = "bcm2708-i2s.0", + .codec_name = "wm8804.1-003b", + .dai_fmt = SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_NB_NF | + SND_SOC_DAIFMT_CBM_CFM, + .ops = &digidac1_soundcard_ops, + .init = digidac1_soundcard_init, + }, + { + .name = "RRA DigiDAC11", + .stream_name = "RRA DigiDAC11 HiFi", + .cpu_dai_name = "wm8804-spdif", + .codec_dai_name = "wm8741", + .codec_name = "wm8741.1-001a", + .dai_fmt = SND_SOC_DAIFMT_I2S + | SND_SOC_DAIFMT_NB_NF + | SND_SOC_DAIFMT_CBS_CFS, + }, +}; + +/* audio machine driver */ +static struct snd_soc_card digidac1_soundcard = { + .name = "digidac1-soundcard", + .owner = THIS_MODULE, + .dai_link = digidac1_soundcard_dai, + .num_links = ARRAY_SIZE(digidac1_soundcard_dai), +}; + +static int digidac1_soundcard_probe(struct platform_device *pdev) +{ + int ret = 0; + + digidac1_soundcard.dev = &pdev->dev; + + if (pdev->dev.of_node) { + struct device_node *i2s_node; + struct snd_soc_dai_link *dai = &digidac1_soundcard_dai[0]; + + i2s_node = of_parse_phandle(pdev->dev.of_node, + "i2s-controller", 0); + + if (i2s_node) { + dai->cpu_dai_name = NULL; + dai->cpu_of_node = i2s_node; + dai->platform_name = NULL; + dai->platform_of_node = i2s_node; + } + } + + ret = snd_soc_register_card(&digidac1_soundcard); + if (ret) + dev_err(&pdev->dev, "snd_soc_register_card() failed: %d\n", + ret); + + return ret; +} + +static int digidac1_soundcard_remove(struct platform_device *pdev) +{ + return snd_soc_unregister_card(&digidac1_soundcard); +} + +static const struct of_device_id digidac1_soundcard_of_match[] = { + { .compatible = "rra,digidac1-soundcard", }, + {}, +}; +MODULE_DEVICE_TABLE(of, digidac1_soundcard_of_match); + +static struct platform_driver digidac1_soundcard_driver = { + .driver = { + .name = "digidac1-audio", + .owner = THIS_MODULE, + .of_match_table = digidac1_soundcard_of_match, + }, + .probe = digidac1_soundcard_probe, + .remove = digidac1_soundcard_remove, +}; + +module_platform_driver(digidac1_soundcard_driver); + +MODULE_AUTHOR("José M. Tasende "); +MODULE_DESCRIPTION("ASoC Driver for RRA DigiDAC1"); +MODULE_LICENSE("GPL v2");