sound: Add a driver for the i8254 beep

Add a sound driver which can output simple beeps using this legacy timer.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

diff --git a/drivers/sound/Kconfig b/drivers/sound/Kconfig
index 4b893f035b0284b8905205d3c84dfd2875293507..c1847df07faf0eb2914a526db3ccf703e52d8d0b 100644 (file)
--- a/drivers/sound/Kconfig
+++ b/drivers/sound/Kconfig
@@ -40,6 +40,18 @@ config I2S_SAMSUNG
          option provides an implementation for sound_init() and
          sound_play().
 
+config SOUND_I8254
+       bool "Intel i8254 timer / beeper"
+       depends on SOUND
+       help
+         This enables support for a beeper that uses the i8254 timer chip.
+         This can emit beeps at a fixed frequency. It is possible to control
+         the length of the beeps, by turning a beep on, waiting for a period
+         of time, then turning it off.
+
+         This is quite an old feature, called PIT (Programmable Interval
+         Timer), but is nonetheless still available on modern x86 machines.
+
 config SOUND_INTEL_HDA
        bool "Intel HDA audio codec"
        depends on SOUND

diff --git a/drivers/sound/Makefile b/drivers/sound/Makefile
index 771c11651673d6429f129e9774a6dad9e88151d7..2a6fd7420c25ce9ef05b3adee2079d5ba8cd16ba 100644 (file)
--- a/drivers/sound/Makefile
+++ b/drivers/sound/Makefile
@@ -16,4 +16,5 @@ obj-$(CONFIG_SOUND_MAX98088)  += max98088.o maxim_codec.o
 obj-$(CONFIG_SOUND_MAX98090)   += max98090.o maxim_codec.o
 obj-$(CONFIG_SOUND_MAX98095)   += max98095.o maxim_codec.o
 obj-$(CONFIG_SOUND_INTEL_HDA)  += hda_codec.o
+obj-$(CONFIG_SOUND_I8254)      += i8254_beep.o
 obj-$(CONFIG_SOUND_IVYBRIDGE)  += ivybridge_sound.o

diff --git a/drivers/sound/i8254_beep.c b/drivers/sound/i8254_beep.c
new file mode 100644 (file)
index 0000000..5572dc4
--- /dev/null
+++ b/drivers/sound/i8254_beep.c
@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2018 Google LLC
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <sound.h>
+#include <asm/i8254.h>
+
+int i8254_start_beep(struct udevice *dev, int frequency_hz)
+{
+       return i8254_enable_beep(frequency_hz);
+}
+
+int i8254_stop_beep(struct udevice *dev)
+{
+       i8254_disable_beep();
+
+       return 0;
+}
+
+static const struct sound_ops i8254_ops = {
+       .start_beep     = i8254_start_beep,
+       .stop_beep      = i8254_stop_beep,
+};
+
+static const struct udevice_id i8254_ids[] = {
+       { .compatible = "i8254,beeper" },
+       { }
+};
+
+U_BOOT_DRIVER(i8254_drv) = {
+       .name           = "i8254_drv",
+       .id             = UCLASS_SOUND,
+       .of_match       = i8254_ids,
+       .ops            = &i8254_ops,
+};