diff options
Diffstat (limited to 'sound/soc/omap/gta04-fm.c')
| -rw-r--r-- | sound/soc/omap/gta04-fm.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/sound/soc/omap/gta04-fm.c b/sound/soc/omap/gta04-fm.c new file mode 100644 index 0000000..3bc0a0f --- /dev/null +++ b/sound/soc/omap/gta04-fm.c @@ -0,0 +1,187 @@ +/* + * Copyright (C) 2011 John Ogness + * Author: John Ogness <john.ogness@linutronix.de> + * + * based on sound/soc/omap/omap3beagle.c by + * Steve Sakoman <steve@sakoman.com> + * + * 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. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind, + * whether express or implied; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ + +#include <linux/platform_device.h> + +#include <linux/module.h> +#include <sound/core.h> +#include <sound/pcm.h> +#include <sound/soc.h> +#include <sound/soc-dapm.h> + +#include "mcbsp.h" +#include "omap-mcbsp.h" +#include "../codecs/si47xx.h" + +/* FCLK is 96 MHz and is divided by the CLOCK_DIVISOR to generate the McBSP CLKX signal + going to DCLK of the Si47xx. + + The DCLK clock cycle time should be between 26 ns (38.4 MHz) and 420 ns (2.38 MHz). + + Please note that the Si47xx requires to set the sampling rate property to 0 Hz + through I2C/SPI before removing (lowering < 2 MHz) or applying the clock. + Otherwise the chip may need a reset. + + 2.5 MHz is sufficient for 24 bit stereo with 48 kHz sample rate while 2.594 MHz + tries to avoid harmonics at typical FM frequencies like 93.5 or 98.5 MHz. But + we can't avoid the 96.0 MHz jamming. So we choose a CLOCK_DIVISOR of 37. + + */ + +#define IN_FREQUENCY (96000000) +#define CLOCK_DIVISOR (IN_FREQUENCY / 2594000) /* 37 */ + +static int gta04_fm_hw_params(struct snd_pcm_substream *substream, + struct snd_pcm_hw_params *params) +{ + /* setup codec dai and cpu dai hardware params */ + struct snd_soc_pcm_runtime *rtd = substream->private_data; + // struct snd_soc_dai *codec_dai = rtd->dai->codec_dai; + struct snd_soc_dai *cpu_dai = rtd->cpu_dai; + unsigned int fmt; + int ret; + + printk("gta04_fm_hw_params\n"); + fmt = SND_SOC_DAIFMT_I2S | /* I2S */ + SND_SOC_DAIFMT_NB_NF | // is this the right setting? + SND_SOC_DAIFMT_CBS_CFS; /* clock and frame signals go from McBSP to Si47xx receiver */ + + /* Set cpu DAI configuration */ + ret = snd_soc_dai_set_fmt(cpu_dai, fmt); + if (ret < 0) { + printk(KERN_ERR "can't set cpu DAI configuration\n"); + return ret; + } + + ret = snd_soc_dai_set_sysclk(cpu_dai, OMAP_MCBSP_SYSCLK_CLKS_FCLK, IN_FREQUENCY, + SND_SOC_CLOCK_IN); + if (ret < 0) { + printk(KERN_ERR "can't set cpu system clock\n"); + return ret; + } + + ret = snd_soc_dai_set_clkdiv(cpu_dai, OMAP_MCBSP_CLKGDV, CLOCK_DIVISOR); + if (ret < 0) { + printk(KERN_ERR "can't set cpu clock divisor\n"); + return ret; + } + + return 0; +} + +static int gta04_fm_init(struct snd_soc_pcm_runtime *runtime) +{ + /* add controls */ + /* add routes */ + /* setup pins */ + struct snd_soc_codec *codec = runtime->codec; + struct snd_soc_dapm_context *dapm = &codec->dapm; + snd_soc_dapm_sync(dapm); + return 0; +} + +static int gta04_fm_startup(struct snd_pcm_substream *substream) +{ + printk("gta04_fm_startup\n"); + /* enable clock used by codec */ + return 0; +} + +static void gta04_fm_shutdown(struct snd_pcm_substream *substream) +{ + printk("gta04_fm_shutdown\n"); + /* disable clock used by codec */ +} + +static struct snd_soc_ops gta04_fm_ops = { + .startup = gta04_fm_startup, + .hw_params = gta04_fm_hw_params, + .shutdown = gta04_fm_shutdown, +}; + +/* digital fm interface glue - connects codec <--> cpu */ +static struct snd_soc_dai_link gta04_fm_dai = { + .name = "Si47xx", + .stream_name = "Si47xx", + .cpu_dai_name = "omap-mcbsp.1", + .platform_name = "omap-pcm-audio", + .codec_dai_name = "Si47xx", + .codec_name = "si47xx_codec_audio", + .init = gta04_fm_init, + .ops = >a04_fm_ops, +}; + +/* fm machine driver */ +static struct snd_soc_card gta04_fm_card = { + .name = "gta04-fm", + .dai_link = >a04_fm_dai, + .num_links = 1, +}; + +#if 0 // this code did configure for I2C in 2.6.32 - how to do it now? + +/* fm subsystem */ +static struct si47xx_setup_data gta04_fm_soc_data = { + .i2c_bus = 2, + .i2c_address = 0x11, +}; +static struct snd_soc_device gta04_fm_devdata = { + .card = >a04_fm_card, + .codec_dev = &soc_codec_dev_si47xx, + .codec_data = >a04_fm_soc_data, +}; +#endif + +static struct platform_device *gta04_fm_snd_device; + +static int __init gta04_fm_soc_init(void) +{ + struct device *dev; + int ret; + + pr_info("gta04-fm SoC init\n"); + + gta04_fm_snd_device = platform_device_alloc("soc-audio", 3); + if (!gta04_fm_snd_device) { + printk(KERN_ERR "platform device allocation failed\n"); + return -ENOMEM; + } + + dev = >a04_fm_snd_device->dev; + + platform_set_drvdata(gta04_fm_snd_device, >a04_fm_card); + + ret = platform_device_add(gta04_fm_snd_device); + if (ret) { + printk(KERN_ERR "unable to add platform device\n"); + platform_device_put(gta04_fm_snd_device); + } + + return ret; +} + +static void __exit gta04_fm_soc_exit(void) +{ + platform_device_unregister(gta04_fm_snd_device); +} + +module_init(gta04_fm_soc_init); +module_exit(gta04_fm_soc_exit); + +MODULE_AUTHOR("John Ogness <john.ogness@linutronix.de>"); +MODULE_DESCRIPTION("ALSA SoC GTA04 FM"); +MODULE_LICENSE("GPL v2"); |