From 85ef9efcc598bff1d783620e23c09aed873e7aee Mon Sep 17 00:00:00 2001
From: gtrainavicius <gtrainavicius@users.noreply.github.com>
Date: Sun, 23 Oct 2016 12:06:53 +0300
Subject: [PATCH] Support for Blokas Labs pisound board
Pisound dynamic overlay (#1760)
Restructuring pisound-overlay.dts, so it can be loaded and unloaded dynamically using dtoverlay.
Print a logline when the kernel module is removed.
pisound improvements:
* Added a writable sysfs object to enable scripts / user space software
to blink MIDI activity LEDs for variable duration.
* Improved hw_param constraints setting.
* Added compatibility with S16_LE sample format.
* Exposed some simple placeholder volume controls, so the card appears
in volumealsa widget.
Add missing SND_PISOUND selects dependency to SND_RAWMIDI
Without it the Pisound module fails to compile.
See https://github.com/raspberrypi/linux/issues/2366
Updates for Pisound module code:
* Merged 'Fix a warning in DEBUG builds' (1c8b82b).
* Updating some strings and copyright information.
* Fix for handling high load of MIDI input and output.
* Use dual rate oversampling ratio for 96kHz instead of single
rate one.
Signed-off-by: Giedrius Trainavicius <giedrius@blokas.io>
Fixing memset call in pisound.c
Signed-off-by: Giedrius Trainavicius <giedrius@blokas.io>
Fix for Pisound's MIDI Input getting blocked for a while in rare cases.
There was a possible race condition which could lead to Input's FIFO queue
to be underflown, causing high amount of processing in the worker thread for
some period of time.
Signed-off-by: Giedrius Trainavicius <giedrius@blokas.io>
---
.../devicetree/bindings/vendor-prefixes.txt | 1 +
sound/soc/bcm/pisound.c | 1204 +++++++++++++++++
2 files changed, 1205 insertions(+)
create mode 100644 sound/soc/bcm/pisound.c
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -56,6 +56,7 @@ axis Axis Communications AB
bananapi BIPAI KEJI LIMITED
bhf Beckhoff Automation GmbH & Co. KG
bitmain Bitmain Technologies
+blokaslabs Vilniaus Blokas UAB
boe BOE Technology Group Co., Ltd.
bosch Bosch Sensortec GmbH
boundary Boundary Devices Inc.
--- /dev/null
+++ b/sound/soc/bcm/pisound.c
@@ -0,0 +1,1204 @@
+/*
+ * Pisound Linux kernel module.
+ * Copyright (C) 2016-2017 Vilniaus Blokas UAB, https://blokas.io/pisound
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/gpio.h>
+#include <linux/kobject.h>
+#include <linux/sysfs.h>
+#include <linux/delay.h>
+#include <linux/spi/spi.h>
+#include <linux/interrupt.h>
+#include <linux/kfifo.h>
+#include <linux/jiffies.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <sound/jack.h>
+#include <sound/rawmidi.h>
+#include <sound/asequencer.h>
+#include <sound/control.h>
+
+static int pisnd_spi_init(struct device *dev);
+static void pisnd_spi_uninit(void);
+
+static void pisnd_spi_flush(void);
+static void pisnd_spi_start(void);
+static uint8_t pisnd_spi_recv(uint8_t *buffer, uint8_t length);
+
+typedef void (*pisnd_spi_recv_cb)(void *data);
+static void pisnd_spi_set_callback(pisnd_spi_recv_cb cb, void *data);
+
+static const char *pisnd_spi_get_serial(void);
+static const char *pisnd_spi_get_id(void);
+static const char *pisnd_spi_get_version(void);
+
+static int pisnd_midi_init(struct snd_card *card);
+static void pisnd_midi_uninit(void);
+
+enum task_e {
+ TASK_PROCESS = 0,
+};
+
+static void pisnd_schedule_process(enum task_e task);
+
+#define PISOUND_LOG_PREFIX "pisound: "
+
+#ifdef PISOUND_DEBUG
+# define printd(...) pr_alert(PISOUND_LOG_PREFIX __VA_ARGS__)
+#else
+# define printd(...) do {} while (0)
+#endif
+
+#define printe(...) pr_err(PISOUND_LOG_PREFIX __VA_ARGS__)
+#define printi(...) pr_info(PISOUND_LOG_PREFIX __VA_ARGS__)
+
+static struct snd_rawmidi *g_rmidi;
+static struct snd_rawmidi_substream *g_midi_output_substream;
+
+static int pisnd_output_open(struct snd_rawmidi_substream *substream)
+{
+ g_midi_output_substream = substream;
+ return 0;
+}
+
+static int pisnd_output_close(struct snd_rawmidi_substream *substream)
+{
+ g_midi_output_substream = NULL;
+ return 0;
+}
+
+static void pisnd_output_trigger(
+ struct snd_rawmidi_substream *substream,
+ int up
+ )
+{
+ if (substream != g_midi_output_substream) {
+ printe("MIDI output trigger called for an unexpected stream!");
+ return;
+ }
+
+ if (!up)
+ return;
+
+ pisnd_spi_start();
+}
+
+static void pisnd_output_drain(struct snd_rawmidi_substream *substream)
+{
+ pisnd_spi_flush();
+}
+
+static int pisnd_input_open(struct snd_rawmidi_substream *substream)
+{
+ return 0;
+}
+
+static int pisnd_input_close(struct snd_rawmidi_substream *substream)
+{
+ return 0;
+}
+
+static void pisnd_midi_recv_callback(void *substream)
+{
+ uint8_t data[128];
+ uint8_t n = 0;
+
+ while ((n = pisnd_spi_recv(data, sizeof(data)))) {
+ int res = snd_rawmidi_receive(substream, data, n);
+ (void)res;
+ printd("midi recv %u bytes, res = %d\n", n, res);
+ }
+}
+
+static void pisnd_input_trigger(struct snd_rawmidi_substream *substream, int up)
+{
+ if (up) {
+ pisnd_spi_set_callback(pisnd_midi_recv_callback, substream);
+ pisnd_schedule_process(TASK_PROCESS);
+ } else {
+ pisnd_spi_set_callback(NULL, NULL);
+ }
+}
+
+static struct snd_rawmidi_ops pisnd_output_ops = {
+ .open = pisnd_output_open,
+ .close = pisnd_output_close,
+ .trigger = pisnd_output_trigger,
+ .drain = pisnd_output_drain,
+};
+
+static struct snd_rawmidi_ops pisnd_input_ops = {
+ .open = pisnd_input_open,
+ .close = pisnd_input_close,
+ .trigger = pisnd_input_trigger,
+};
+
+static void pisnd_get_port_info(
+ struct snd_rawmidi *rmidi,
+ int number,
+ struct snd_seq_port_info *seq_port_info
+ )
+{
+ seq_port_info->type =
+ SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC |
+ SNDRV_SEQ_PORT_TYPE_HARDWARE |
+ SNDRV_SEQ_PORT_TYPE_PORT;
+ seq_port_info->midi_voices = 0;
+}
+
+static struct snd_rawmidi_global_ops pisnd_global_ops = {
+ .get_port_info = pisnd_get_port_info,
+};
+
+static int pisnd_midi_init(struct snd_card *card)
+{
+ int err;
+
+ g_midi_output_substream = NULL;
+
+ err = snd_rawmidi_new(card, "pisound MIDI", 0, 1, 1, &g_rmidi);
+
+ if (err < 0) {
+ printe("snd_rawmidi_new failed: %d\n", err);
+ return err;
+ }
+
+ strcpy(g_rmidi->name, "pisound MIDI ");
+ strcat(g_rmidi->name, pisnd_spi_get_serial());
+
+ g_rmidi->info_flags =
+ SNDRV_RAWMIDI_INFO_OUTPUT |
+ SNDRV_RAWMIDI_INFO_INPUT |
+ SNDRV_RAWMIDI_INFO_DUPLEX;
+
+ g_rmidi->ops = &pisnd_global_ops;
+
+ g_rmidi->private_data = (void *)0;
+
+ snd_rawmidi_set_ops(
+ g_rmidi,
+ SNDRV_RAWMIDI_STREAM_OUTPUT,
+ &pisnd_output_ops
+ );
+
+ snd_rawmidi_set_ops(
+ g_rmidi,
+ SNDRV_RAWMIDI_STREAM_INPUT,
+ &pisnd_input_ops
+ );
+
+ return 0;
+}
+
+static void pisnd_midi_uninit(void)
+{
+}
+
+static void *g_recvData;
+static pisnd_spi_recv_cb g_recvCallback;
+
+#define FIFO_SIZE 4096
+
+static char g_serial_num[11];
+static char g_id[25];
+static char g_version[5];
+
+static uint8_t g_ledFlashDuration;
+static bool g_ledFlashDurationChanged;
+
+DEFINE_KFIFO(spi_fifo_in, uint8_t, FIFO_SIZE);
+DEFINE_KFIFO(spi_fifo_out, uint8_t, FIFO_SIZE);
+
+static struct gpio_desc *data_available;
+static struct gpio_desc *spi_reset;
+
+static struct spi_device *pisnd_spi_device;
+
+static struct workqueue_struct *pisnd_workqueue;
+static struct work_struct pisnd_work_process;
+
+static void pisnd_work_handler(struct work_struct *work);
+
+static void spi_transfer(const uint8_t *txbuf, uint8_t *rxbuf, int len);
+static uint16_t spi_transfer16(uint16_t val);
+
+static int pisnd_init_workqueues(void)
+{
+ pisnd_workqueue = create_singlethread_workqueue("pisnd_workqueue");
+ INIT_WORK(&pisnd_work_process, pisnd_work_handler);
+
+ return 0;
+}
+
+static void pisnd_uninit_workqueues(void)
+{
+ flush_workqueue(pisnd_workqueue);
+ destroy_workqueue(pisnd_workqueue);
+
+ pisnd_workqueue = NULL;
+}
+
+static bool pisnd_spi_has_more(void)
+{
+ return gpiod_get_value(data_available);
+}
+
+static void pisnd_schedule_process(enum task_e task)
+{
+ if (pisnd_spi_device != NULL &&
+ pisnd_workqueue != NULL &&
+ !work_pending(&pisnd_work_process)
+ ) {
+ printd("schedule: has more = %d\n", pisnd_spi_has_more());
+ if (task == TASK_PROCESS)
+ queue_work(pisnd_workqueue, &pisnd_work_process);
+ }
+}
+
+static irqreturn_t data_available_interrupt_handler(int irq, void *dev_id)
+{
+ if (irq == gpiod_to_irq(data_available) && pisnd_spi_has_more()) {
+ printd("schedule from irq\n");
+ pisnd_schedule_process(TASK_PROCESS);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static DEFINE_SPINLOCK(spilock);
+static unsigned long spilockflags;
+
+static uint16_t spi_transfer16(uint16_t val)
+{
+ uint8_t txbuf[2];
+ uint8_t rxbuf[2];
+
+ if (!pisnd_spi_device) {
+ printe("pisnd_spi_device null, returning\n");
+ return 0;
+ }
+
+ txbuf[0] = val >> 8;
+ txbuf[1] = val & 0xff;
+
+ spi_transfer(txbuf, rxbuf, sizeof(txbuf));
+
+ printd("received: %02x%02x\n", rxbuf[0], rxbuf[1]);
+
+ return (rxbuf[0] << 8) | rxbuf[1];
+}
+
+static void spi_transfer(const uint8_t *txbuf, uint8_t *rxbuf, int len)
+{
+ int err;
+ struct spi_transfer transfer;
+ struct spi_message msg;
+
+ memset(rxbuf, 0, len);
+
+ if (!pisnd_spi_device) {
+ printe("pisnd_spi_device null, returning\n");
+ return;
+ }
+
+ spi_message_init(&msg);
+
+ memset(&transfer, 0, sizeof(transfer));
+
+ transfer.tx_buf = txbuf;
+ transfer.rx_buf = rxbuf;
+ transfer.len = len;
+ transfer.speed_hz = 100000;
+ transfer.delay_usecs = 10;
+ spi_message_add_tail(&transfer, &msg);
+
+ spin_lock_irqsave(&spilock, spilockflags);
+ err = spi_sync(pisnd_spi_device, &msg);
+ spin_unlock_irqrestore(&spilock, spilockflags);
+
+ if (err < 0) {
+ printe("spi_sync error %d\n", err);
+ return;
+ }
+
+ printd("hasMore %d\n", pisnd_spi_has_more());
+}
+
+static int spi_read_bytes(char *dst, size_t length, uint8_t *bytesRead)
+{
+ uint16_t rx;
+ uint8_t size;
+ uint8_t i;
+
+ memset(dst, 0, length);
+ *bytesRead = 0;
+
+ rx = spi_transfer16(0);
+ if (!(rx >> 8))
+ return -EINVAL;
+
+ size = rx & 0xff;
+
+ if (size > length)
+ return -EINVAL;
+
+ for (i = 0; i < size; ++i) {
+ rx = spi_transfer16(0);
+ if (!(rx >> 8))
+ return -EINVAL;
+
+ dst[i] = rx & 0xff;
+ }
+
+ *bytesRead = i;
+
+ return 0;
+}
+
+static int spi_device_match(struct device *dev, void *data)
+{
+ struct spi_device *spi = container_of(dev, struct spi_device, dev);
+
+ printd(" %s %s %dkHz %d bits mode=0x%02X\n",
+ spi->modalias, dev_name(dev), spi->max_speed_hz/1000,
+ spi->bits_per_word, spi->mode);
+
+ if (strcmp("pisound-spi", spi->modalias) == 0) {
+ printi("\tFound!\n");
+ return 1;
+ }
+
+ printe("\tNot found!\n");
+ return 0;
+}
+
+static struct spi_device *pisnd_spi_find_device(void)
+{
+ struct device *dev;
+
+ printi("Searching for spi device...\n");
+ dev = bus_find_device(&spi_bus_type, NULL, NULL, spi_device_match);
+ if (dev != NULL)
+ return container_of(dev, struct spi_device, dev);
+ else
+ return NULL;
+}
+
+static void pisnd_work_handler(struct work_struct *work)
+{
+ enum { TRANSFER_SIZE = 4 };
+ enum { PISOUND_OUTPUT_BUFFER_SIZE = 128 };
+ enum { MIDI_BYTES_PER_SECOND = 3125 };
+ int out_buffer_used = 0;
+ unsigned long now;
+ uint8_t val;
+ uint8_t txbuf[TRANSFER_SIZE];
+ uint8_t rxbuf[TRANSFER_SIZE];
+ uint8_t midibuf[TRANSFER_SIZE];
+ int i, n;
+ bool had_data;
+
+ unsigned long last_transfer_at = jiffies;
+
+ if (work == &pisnd_work_process) {
+ if (pisnd_spi_device == NULL)
+ return;
+
+ do {
+ if (g_midi_output_substream &&
+ kfifo_avail(&spi_fifo_out) >= sizeof(midibuf)) {
+
+ n = snd_rawmidi_transmit_peek(
+ g_midi_output_substream,
+ midibuf, sizeof(midibuf)
+ );
+
+ if (n > 0) {
+ for (i = 0; i < n; ++i)
+ kfifo_put(
+ &spi_fifo_out,
+ midibuf[i]
+ );
+ snd_rawmidi_transmit_ack(
+ g_midi_output_substream,
+ i
+ );
+ }
+ }
+
+ had_data = false;
+ memset(txbuf, 0, sizeof(txbuf));
+ for (i = 0; i < sizeof(txbuf) &&
+ out_buffer_used < PISOUND_OUTPUT_BUFFER_SIZE;
+ i += 2) {
+
+ val = 0;
+
+ if (g_ledFlashDurationChanged) {
+ txbuf[i+0] = 0xf0;
+ txbuf[i+1] = g_ledFlashDuration;
+ g_ledFlashDuration = 0;
+ g_ledFlashDurationChanged = false;
+ } else if (kfifo_get(&spi_fifo_out, &val)) {
+ txbuf[i+0] = 0x0f;
+ txbuf[i+1] = val;
+ ++out_buffer_used;
+ }
+ }
+
+ spi_transfer(txbuf, rxbuf, sizeof(txbuf));
+ /* Estimate the Pisound's MIDI output buffer usage, so
+ * that we don't overflow it. Space in the buffer should
+ * be becoming available at the UART MIDI byte transfer
+ * rate.
+ */
+ now = jiffies;
+ out_buffer_used -=
+ (MIDI_BYTES_PER_SECOND / HZ) /
+ (now - last_transfer_at);
+ if (out_buffer_used < 0)
+ out_buffer_used = 0;
+ last_transfer_at = now;
+
+ for (i = 0; i < sizeof(rxbuf); i += 2) {
+ if (rxbuf[i]) {
+ kfifo_put(&spi_fifo_in, rxbuf[i+1]);
+ if (kfifo_len(&spi_fifo_in) > 16 &&
+ g_recvCallback)
+ g_recvCallback(g_recvData);
+ had_data = true;
+ }
+ }
+ } while (had_data
+ || !kfifo_is_empty(&spi_fifo_out)
+ || pisnd_spi_has_more()
+ || g_ledFlashDurationChanged
+ );
+
+ if (!kfifo_is_empty(&spi_fifo_in) && g_recvCallback)
+ g_recvCallback(g_recvData);
+ }
+}
+
+static int pisnd_spi_gpio_init(struct device *dev)
+{
+ spi_reset = gpiod_get_index(dev, "reset", 1, GPIOD_ASIS);
+ data_available = gpiod_get_index(dev, "data_available", 0, GPIOD_ASIS);
+
+ gpiod_direction_output(spi_reset, 1);
+ gpiod_direction_input(data_available);
+
+ /* Reset the slave. */
+ gpiod_set_value(spi_reset, false);
+ mdelay(1);
+ gpiod_set_value(spi_reset, true);
+
+ /* Give time for spi slave to start. */
+ mdelay(64);
+
+ return 0;
+}
+
+static void pisnd_spi_gpio_uninit(void)
+{
+ gpiod_set_value(spi_reset, false);
+ gpiod_put(spi_reset);
+ spi_reset = NULL;
+
+ gpiod_put(data_available);
+ data_available = NULL;
+}
+
+static int pisnd_spi_gpio_irq_init(struct device *dev)
+{
+ return request_irq(
+ gpiod_to_irq(data_available),
+ data_available_interrupt_handler,
+ IRQF_TIMER | IRQF_TRIGGER_RISING,
+ "data_available_int",
+ NULL
+ );
+}
+
+static void pisnd_spi_gpio_irq_uninit(void)
+{
+ free_irq(gpiod_to_irq(data_available), NULL);
+}
+
+static int spi_read_info(void)
+{
+ uint16_t tmp;
+ uint8_t count;
+ uint8_t n;
+ uint8_t i;
+ uint8_t j;
+ char buffer[257];
+ int ret;
+ char *p;
+
+ memset(g_serial_num, 0, sizeof(g_serial_num));
+ memset(g_version, 0, sizeof(g_version));
+ memset(g_id, 0, sizeof(g_id));
+
+ tmp = spi_transfer16(0);
+
+ if (!(tmp >> 8))
+ return -EINVAL;
+
+ count = tmp & 0xff;
+
+ for (i = 0; i < count; ++i) {
+ memset(buffer, 0, sizeof(buffer));
+ ret = spi_read_bytes(buffer, sizeof(buffer)-1, &n);
+
+ if (ret < 0)
+ return ret;
+
+ switch (i) {
+ case 0:
+ if (n != 2)
+ return -EINVAL;
+
+ snprintf(
+ g_version,
+ sizeof(g_version),
+ "%x.%02x",
+ buffer[0],
+ buffer[1]
+ );
+ break;
+ case 1:
+ if (n >= sizeof(g_serial_num))
+ return -EINVAL;
+
+ memcpy(g_serial_num, buffer, sizeof(g_serial_num));
+ break;
+ case 2:
+ {
+ if (n >= sizeof(g_id))
+ return -EINVAL;
+
+ p = g_id;
+ for (j = 0; j < n; ++j)
+ p += sprintf(p, "%02x", buffer[j]);
+ }
+ break;
+ default:
+ break;
+ }
+ }
+
+ return 0;
+}
+
+static int pisnd_spi_init(struct device *dev)
+{
+ int ret;
+ struct spi_device *spi;
+
+ memset(g_serial_num, 0, sizeof(g_serial_num));
+ memset(g_id, 0, sizeof(g_id));
+ memset(g_version, 0, sizeof(g_version));
+
+ spi = pisnd_spi_find_device();
+
+ if (spi != NULL) {
+ printd("initializing spi!\n");
+ pisnd_spi_device = spi;
+ ret = spi_setup(pisnd_spi_device);
+ } else {
+ printe("SPI device not found, deferring!\n");
+ return -EPROBE_DEFER;
+ }
+
+ ret = pisnd_spi_gpio_init(dev);
+
+ if (ret < 0) {
+ printe("SPI GPIO init failed: %d\n", ret);
+ spi_dev_put(pisnd_spi_device);
+ pisnd_spi_device = NULL;
+ pisnd_spi_gpio_uninit();
+ return ret;
+ }
+
+ ret = spi_read_info();
+
+ if (ret < 0) {
+ printe("Reading card info failed: %d\n", ret);
+ spi_dev_put(pisnd_spi_device);
+ pisnd_spi_device = NULL;
+ pisnd_spi_gpio_uninit();
+ return ret;
+ }
+
+ /* Flash the LEDs. */
+ spi_transfer16(0xf008);
+
+ ret = pisnd_spi_gpio_irq_init(dev);
+ if (ret < 0) {
+ printe("SPI irq request failed: %d\n", ret);
+ spi_dev_put(pisnd_spi_device);
+ pisnd_spi_device = NULL;
+ pisnd_spi_gpio_irq_uninit();
+ pisnd_spi_gpio_uninit();
+ }
+
+ ret = pisnd_init_workqueues();
+ if (ret != 0) {
+ printe("Workqueue initialization failed: %d\n", ret);
+ spi_dev_put(pisnd_spi_device);
+ pisnd_spi_device = NULL;
+ pisnd_spi_gpio_irq_uninit();
+ pisnd_spi_gpio_uninit();
+ pisnd_uninit_workqueues();
+ return ret;
+ }
+
+ if (pisnd_spi_has_more()) {
+ printd("data is available, scheduling from init\n");
+ pisnd_schedule_process(TASK_PROCESS);
+ }
+
+ return 0;
+}
+
+static void pisnd_spi_uninit(void)
+{
+ pisnd_uninit_workqueues();
+
+ spi_dev_put(pisnd_spi_device);
+ pisnd_spi_device = NULL;
+
+ pisnd_spi_gpio_irq_uninit();
+ pisnd_spi_gpio_uninit();
+}
+
+static void pisnd_spi_flash_leds(uint8_t duration)
+{
+ g_ledFlashDuration = duration;
+ g_ledFlashDurationChanged = true;
+ printd("schedule from spi_flash_leds\n");
+ pisnd_schedule_process(TASK_PROCESS);
+}
+
+static void pisnd_spi_flush(void)
+{
+ while (!kfifo_is_empty(&spi_fifo_out)) {
+ pisnd_spi_start();
+ flush_workqueue(pisnd_workqueue);
+ }
+}
+
+static void pisnd_spi_start(void)
+{
+ printd("schedule from spi_start\n");
+ pisnd_schedule_process(TASK_PROCESS);
+}
+
+static uint8_t pisnd_spi_recv(uint8_t *buffer, uint8_t length)
+{
+ return kfifo_out(&spi_fifo_in, buffer, length);
+}
+
+static void pisnd_spi_set_callback(pisnd_spi_recv_cb cb, void *data)
+{
+ g_recvData = data;
+ g_recvCallback = cb;
+}
+
+static const char *pisnd_spi_get_serial(void)
+{
+ if (strlen(g_serial_num))
+ return g_serial_num;
+
+ return "";
+}
+
+static const char *pisnd_spi_get_id(void)
+{
+ if (strlen(g_id))
+ return g_id;
+
+ return "";
+}
+
+static const char *pisnd_spi_get_version(void)
+{
+ if (strlen(g_version))
+ return g_version;
+
+ return "";
+}
+
+static const struct of_device_id pisound_of_match[] = {
+ { .compatible = "blokaslabs,pisound", },
+ { .compatible = "blokaslabs,pisound-spi", },
+ {},
+};
+
+enum {
+ SWITCH = 0,
+ VOLUME = 1,
+};
+
+static int pisnd_ctl_info(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_info *uinfo)
+{
+ if (kcontrol->private_value == SWITCH) {
+ uinfo->type = SNDRV_CTL_ELEM_TYPE_BOOLEAN;
+ uinfo->count = 1;
+ uinfo->value.integer.min = 0;
+ uinfo->value.integer.max = 1;
+ return 0;
+ } else if (kcontrol->private_value == VOLUME) {
+ uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+ uinfo->count = 1;
+ uinfo->value.integer.min = 0;
+ uinfo->value.integer.max = 100;
+ return 0;
+ }
+ return -EINVAL;
+}
+
+static int pisnd_ctl_get(struct snd_kcontrol *kcontrol,
+ struct snd_ctl_elem_value *ucontrol)
+{
+ if (kcontrol->private_value == SWITCH) {
+ ucontrol->value.integer.value[0] = 1;
+ return 0;
+ } else if (kcontrol->private_value == VOLUME) {
+ ucontrol->value.integer.value[0] = 100;
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static struct snd_kcontrol_new pisnd_ctl[] = {
+ {
+ .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+ .name = "PCM Playback Switch",
+ .index = 0,
+ .private_value = SWITCH,
+ .access = SNDRV_CTL_ELEM_ACCESS_READ,
+ .info = pisnd_ctl_info,
+ .get = pisnd_ctl_get,
+ },
+ {
+ .iface = SNDRV_CTL_ELEM_IFACE_MIXER,
+ .name = "PCM Playback Volume",
+ .index = 0,
+ .private_value = VOLUME,
+ .access = SNDRV_CTL_ELEM_ACCESS_READ,
+ .info = pisnd_ctl_info,
+ .get = pisnd_ctl_get,
+ },
+};
+
+static int pisnd_ctl_init(struct snd_card *card)
+{
+ int err, i;
+
+ for (i = 0; i < ARRAY_SIZE(pisnd_ctl); ++i) {
+ err = snd_ctl_add(card, snd_ctl_new1(&pisnd_ctl[i], NULL));
+ if (err < 0)
+ return err;
+ }
+
+ return 0;
+}
+
+static int pisnd_ctl_uninit(void)
+{
+ return 0;
+}
+
+static struct gpio_desc *osr0, *osr1, *osr2;
+static struct gpio_desc *reset;
+static struct gpio_desc *button;
+
+static int pisnd_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 *cpu_dai = rtd->cpu_dai;
+
+ /* Pisound runs on fixed 32 clock counts per channel,
+ * as generated by the master ADC.
+ */
+ snd_soc_dai_set_bclk_ratio(cpu_dai, 32*2);
+
+ printd("rate = %d\n", params_rate(params));
+ printd("ch = %d\n", params_channels(params));
+ printd("bits = %u\n",
+ snd_pcm_format_physical_width(params_format(params)));
+ printd("format = %d\n", params_format(params));
+
+ gpiod_set_value(reset, false);
+
+ switch (params_rate(params)) {
+ case 48000:
+ gpiod_set_value(osr0, true);
+ gpiod_set_value(osr1, false);
+ gpiod_set_value(osr2, false);
+ break;
+ case 96000:
+ gpiod_set_value(osr0, true);
+ gpiod_set_value(osr1, false);
+ gpiod_set_value(osr2, true);
+ break;
+ case 192000:
+ gpiod_set_value(osr0, true);
+ gpiod_set_value(osr1, true);
+ gpiod_set_value(osr2, true);
+ break;
+ default:
+ printe("Unsupported rate %u!\n", params_rate(params));
+ return -EINVAL;
+ }
+
+ gpiod_set_value(reset, true);
+
+ return 0;
+}
+
+static unsigned int rates[3] = {
+ 48000, 96000, 192000
+};
+
+static struct snd_pcm_hw_constraint_list constraints_rates = {
+ .count = ARRAY_SIZE(rates),
+ .list = rates,
+ .mask = 0,
+};
+
+static int pisnd_startup(struct snd_pcm_substream *substream)
+{
+ int err = snd_pcm_hw_constraint_list(
+ substream->runtime,
+ 0,
+ SNDRV_PCM_HW_PARAM_RATE,
+ &constraints_rates
+ );
+
+ if (err < 0)
+ return err;
+
+ err = snd_pcm_hw_constraint_single(
+ substream->runtime,
+ SNDRV_PCM_HW_PARAM_CHANNELS,
+ 2
+ );
+
+ if (err < 0)
+ return err;
+
+ err = snd_pcm_hw_constraint_mask64(
+ substream->runtime,
+ SNDRV_PCM_HW_PARAM_FORMAT,
+ SNDRV_PCM_FMTBIT_S16_LE |
+ SNDRV_PCM_FMTBIT_S24_LE |
+ SNDRV_PCM_FMTBIT_S32_LE
+ );
+
+ if (err < 0)
+ return err;
+
+ return 0;
+}
+
+static struct snd_soc_ops pisnd_ops = {
+ .startup = pisnd_startup,
+ .hw_params = pisnd_hw_params,
+};
+
+static struct snd_soc_dai_link pisnd_dai[] = {
+ {
+ .name = "pisound",
+ .stream_name = "pisound",
+ .cpu_dai_name = "bcm2708-i2s.0",
+ .codec_dai_name = "snd-soc-dummy-dai",
+ .platform_name = "bcm2708-i2s.0",
+ .codec_name = "snd-soc-dummy",
+ .dai_fmt =
+ SND_SOC_DAIFMT_I2S |
+ SND_SOC_DAIFMT_NB_NF |
+ SND_SOC_DAIFMT_CBM_CFM,
+ .ops = &pisnd_ops,
+ },
+};
+
+static int pisnd_card_probe(struct snd_soc_card *card)
+{
+ int err = pisnd_midi_init(card->snd_card);
+
+ if (err < 0) {
+ printe("pisnd_midi_init failed: %d\n", err);
+ return err;
+ }
+
+ err = pisnd_ctl_init(card->snd_card);
+ if (err < 0) {
+ printe("pisnd_ctl_init failed: %d\n", err);
+ return err;
+ }
+
+ return 0;
+}
+
+static int pisnd_card_remove(struct snd_soc_card *card)
+{
+ pisnd_ctl_uninit();
+ pisnd_midi_uninit();
+ return 0;
+}
+
+static struct snd_soc_card pisnd_card = {
+ .name = "pisound",
+ .owner = THIS_MODULE,
+ .dai_link = pisnd_dai,
+ .num_links = ARRAY_SIZE(pisnd_dai),
+ .probe = pisnd_card_probe,
+ .remove = pisnd_card_remove,
+};
+
+static int pisnd_init_gpio(struct device *dev)
+{
+ osr0 = gpiod_get_index(dev, "osr", 0, GPIOD_ASIS);
+ osr1 = gpiod_get_index(dev, "osr", 1, GPIOD_ASIS);
+ osr2 = gpiod_get_index(dev, "osr", 2, GPIOD_ASIS);
+
+ reset = gpiod_get_index(dev, "reset", 0, GPIOD_ASIS);
+
+ button = gpiod_get_index(dev, "button", 0, GPIOD_ASIS);
+
+ gpiod_direction_output(osr0, 1);
+ gpiod_direction_output(osr1, 1);
+ gpiod_direction_output(osr2, 1);
+ gpiod_direction_output(reset, 1);
+
+ gpiod_set_value(reset, false);
+ gpiod_set_value(osr0, true);
+ gpiod_set_value(osr1, false);
+ gpiod_set_value(osr2, false);
+ gpiod_set_value(reset, true);
+
+ gpiod_export(button, false);
+
+ return 0;
+}
+
+static int pisnd_uninit_gpio(void)
+{
+ int i;
+
+ struct gpio_desc **gpios[] = {
+ &osr0, &osr1, &osr2, &reset, &button,
+ };
+
+ gpiod_unexport(button);
+
+ for (i = 0; i < ARRAY_SIZE(gpios); ++i) {
+ if (*gpios[i] == NULL) {
+ printd("weird, GPIO[%d] is NULL already\n", i);
+ continue;
+ }
+
+ gpiod_put(*gpios[i]);
+ *gpios[i] = NULL;
+ }
+
+ return 0;
+}
+
+static struct kobject *pisnd_kobj;
+
+static ssize_t pisnd_serial_show(
+ struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf
+ )
+{
+ return sprintf(buf, "%s\n", pisnd_spi_get_serial());
+}
+
+static ssize_t pisnd_id_show(
+ struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf
+ )
+{
+ return sprintf(buf, "%s\n", pisnd_spi_get_id());
+}
+
+static ssize_t pisnd_version_show(
+ struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf
+ )
+{
+ return sprintf(buf, "%s\n", pisnd_spi_get_version());
+}
+
+static ssize_t pisnd_led_store(
+ struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf,
+ size_t length
+ )
+{
+ uint32_t timeout;
+ int err;
+
+ err = kstrtou32(buf, 10, &timeout);
+
+ if (err == 0 && timeout <= 255)
+ pisnd_spi_flash_leds(timeout);
+
+ return length;
+}
+
+static struct kobj_attribute pisnd_serial_attribute =
+ __ATTR(serial, 0444, pisnd_serial_show, NULL);
+static struct kobj_attribute pisnd_id_attribute =
+ __ATTR(id, 0444, pisnd_id_show, NULL);
+static struct kobj_attribute pisnd_version_attribute =
+ __ATTR(version, 0444, pisnd_version_show, NULL);
+static struct kobj_attribute pisnd_led_attribute =
+ __ATTR(led, 0644, NULL, pisnd_led_store);
+
+static struct attribute *attrs[] = {
+ &pisnd_serial_attribute.attr,
+ &pisnd_id_attribute.attr,
+ &pisnd_version_attribute.attr,
+ &pisnd_led_attribute.attr,
+ NULL
+};
+
+static struct attribute_group attr_group = { .attrs = attrs };
+
+static int pisnd_probe(struct platform_device *pdev)
+{
+ int ret = 0;
+ int i;
+
+ ret = pisnd_spi_init(&pdev->dev);
+ if (ret < 0) {
+ printe("pisnd_spi_init failed: %d\n", ret);
+ return ret;
+ }
+
+ printi("Detected Pisound card:\n");
+ printi("\tSerial: %s\n", pisnd_spi_get_serial());
+ printi("\tVersion: %s\n", pisnd_spi_get_version());
+ printi("\tId: %s\n", pisnd_spi_get_id());
+
+ pisnd_kobj = kobject_create_and_add("pisound", kernel_kobj);
+ if (!pisnd_kobj) {
+ pisnd_spi_uninit();
+ return -ENOMEM;
+ }
+
+ ret = sysfs_create_group(pisnd_kobj, &attr_group);
+ if (ret < 0) {
+ pisnd_spi_uninit();
+ kobject_put(pisnd_kobj);
+ return -ENOMEM;
+ }
+
+ pisnd_init_gpio(&pdev->dev);
+ pisnd_card.dev = &pdev->dev;
+
+ if (pdev->dev.of_node) {
+ struct device_node *i2s_node;
+
+ i2s_node = of_parse_phandle(
+ pdev->dev.of_node,
+ "i2s-controller",
+ 0
+ );
+
+ for (i = 0; i < pisnd_card.num_links; ++i) {
+ struct snd_soc_dai_link *dai = &pisnd_dai[i];
+
+ if (i2s_node) {
+ dai->cpu_dai_name = NULL;
+ dai->cpu_of_node = i2s_node;
+ dai->platform_name = NULL;
+ dai->platform_of_node = i2s_node;
+ dai->stream_name = pisnd_spi_get_serial();
+ }
+ }
+ }
+
+ ret = snd_soc_register_card(&pisnd_card);
+
+ if (ret < 0) {
+ if (ret != -EPROBE_DEFER)
+ printe("snd_soc_register_card() failed: %d\n", ret);
+ pisnd_uninit_gpio();
+ kobject_put(pisnd_kobj);
+ pisnd_spi_uninit();
+ }
+
+ return ret;
+}
+
+static int pisnd_remove(struct platform_device *pdev)
+{
+ printi("Unloading.\n");
+
+ if (pisnd_kobj) {
+ kobject_put(pisnd_kobj);
+ pisnd_kobj = NULL;
+ }
+
+ pisnd_spi_uninit();
+
+ /* Turn off */
+ gpiod_set_value(reset, false);
+ pisnd_uninit_gpio();
+
+ return snd_soc_unregister_card(&pisnd_card);
+}
+
+MODULE_DEVICE_TABLE(of, pisound_of_match);
+
+static struct platform_driver pisnd_driver = {
+ .driver = {
+ .name = "snd-rpi-pisound",
+ .owner = THIS_MODULE,
+ .of_match_table = pisound_of_match,
+ },
+ .probe = pisnd_probe,
+ .remove = pisnd_remove,
+};
+
+module_platform_driver(pisnd_driver);
+
+MODULE_AUTHOR("Giedrius Trainavicius <giedrius@blokas.io>");
+MODULE_DESCRIPTION("ASoC Driver for Pisound, https://blokas.io/pisound");
+MODULE_LICENSE("GPL v2");