[alsa-devel] [PATCH RFC 1/6] ASoC: samsung: Add Samsung Low Power Audio Subsystem driver
Sylwester Nawrocki
s.nawrocki at samsung.com
Mon Jun 13 12:52:35 CEST 2016
From: Inha Song <ideal.song at samsung.com>
This patch adds LPASS driver. The LPASS (Low Power Audio Subsystem)
is a special subsystem that supports audio playback with low power
consumption. This is a minimal driver which prepares resources for
IP blocks like I2S, audio DMA and UART.
Also system power ops are added to ensure the Audio Subsystem is
operational after system suspend/resume cycle.
Signed-off-by: Inha Song <ideal.song at samsung.com>
Signed-off-by: Beomho Seo <beomho.seo at samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki at samsung.com>
---
sound/soc/samsung/Makefile | 2 +
sound/soc/samsung/lpass.c | 162 +++++++++++++++++++++++++++++++++++++++++++++
sound/soc/samsung/lpass.h | 47 +++++++++++++
3 files changed, 211 insertions(+)
create mode 100644 sound/soc/samsung/lpass.c
create mode 100644 sound/soc/samsung/lpass.h
diff --git a/sound/soc/samsung/Makefile b/sound/soc/samsung/Makefile
index 5d03f5c..2b919d5 100644
--- a/sound/soc/samsung/Makefile
+++ b/sound/soc/samsung/Makefile
@@ -8,6 +8,7 @@ snd-soc-s3c-i2s-v2-objs := s3c-i2s-v2.o
snd-soc-samsung-spdif-objs := spdif.o
snd-soc-pcm-objs := pcm.o
snd-soc-i2s-objs := i2s.o
+snd-soc-lpass-objs := lpass.o
obj-$(CONFIG_SND_SOC_SAMSUNG) += snd-soc-s3c-dma.o
obj-$(CONFIG_SND_S3C24XX_I2S) += snd-soc-s3c24xx-i2s.o
@@ -18,6 +19,7 @@ obj-$(CONFIG_SND_SAMSUNG_SPDIF) += snd-soc-samsung-spdif.o
obj-$(CONFIG_SND_SAMSUNG_PCM) += snd-soc-pcm.o
obj-$(CONFIG_SND_SAMSUNG_I2S) += snd-soc-i2s.o
obj-$(CONFIG_SND_SAMSUNG_I2S) += snd-soc-idma.o
+obj-$(CONFIG_SND_SAMSUNG_AUDSS) += snd-soc-lpass.o
# S3C24XX Machine Support
snd-soc-jive-wm8750-objs := jive_wm8750.o
diff --git a/sound/soc/samsung/lpass.c b/sound/soc/samsung/lpass.c
new file mode 100644
index 0000000..57198cf
--- /dev/null
+++ b/sound/soc/samsung/lpass.c
@@ -0,0 +1,162 @@
+/*
+ * Copyright (C) 2015 - 2016 Samsung Electronics Co., Ltd.
+ * Inha Song <ideal.song at samsung.com>
+ *
+ * Low Power Audio Subsystem driver for Samsung Exynos
+ *
+ * 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; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <sound/soc.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+
+#include "lpass.h"
+
+#define EXYNOS5433_PAD_RETENTION_AUD_OPTION_OFFSET 0x3028
+#define EXYNOS5433_INITIATE_WAKEUP_FROM_LOWPWR_MASK BIT(28)
+
+struct lpass_info {
+ struct platform_device *pdev;
+ void __iomem *reg_sfr;
+ struct regmap *reg_pmu;
+};
+
+static void lpass_core_sw_reset(struct lpass_info *lpass, int bit)
+{
+ unsigned int val;
+
+ val = readl(lpass->reg_sfr + SFR_LPASS_CORE_SW_RESET);
+
+ val &= ~(1 << bit);
+ writel(val, lpass->reg_sfr + SFR_LPASS_CORE_SW_RESET);
+
+ udelay(100);
+
+ val |= 1 << bit;
+ writel(val, lpass->reg_sfr + SFR_LPASS_CORE_SW_RESET);
+}
+
+static void lpass_enable(struct lpass_info *lpass)
+{
+ if (!lpass->reg_pmu)
+ return;
+
+ /* Unmasks SFR, DMA, I2S Interrupt */
+ writel(LPASS_INTR_SFR | LPASS_INTR_DMA | LPASS_INTR_I2S,
+ lpass->reg_sfr + SFR_LPASS_INTR_CA5_MASK);
+
+ writel(LPASS_INTR_DMA | LPASS_INTR_I2S | LPASS_INTR_SFR
+ | LPASS_INTR_UART,
+ lpass->reg_sfr + SFR_LPASS_INTR_CPU_MASK);
+
+ /* Activate related PADs from retention state */
+ regmap_write(lpass->reg_pmu,
+ EXYNOS5433_PAD_RETENTION_AUD_OPTION_OFFSET,
+ EXYNOS5433_INITIATE_WAKEUP_FROM_LOWPWR_MASK);
+
+ lpass_core_sw_reset(lpass, SW_RESET_I2S);
+ lpass_core_sw_reset(lpass, SW_RESET_DMA);
+ lpass_core_sw_reset(lpass, SW_RESET_MEM);
+}
+
+static void lpass_disable(struct lpass_info *lpass)
+{
+ if (!lpass->reg_pmu)
+ return;
+
+ /* Masks SFR, DMA, I2S Interrupt */
+ writel(0, lpass->reg_sfr + SFR_LPASS_INTR_CA5_MASK);
+
+ writel(0, lpass->reg_sfr + SFR_LPASS_INTR_CPU_MASK);
+
+ /* Deactivate related PADs from retention state */
+ regmap_write(lpass->reg_pmu,
+ EXYNOS5433_PAD_RETENTION_AUD_OPTION_OFFSET, 0);
+}
+
+static int lpass_probe(struct platform_device *pdev)
+{
+ struct lpass_info *lpass;
+ struct device *dev = &pdev->dev;
+ struct resource *res;
+
+ if (!dev->of_node) {
+ dev_err(dev, "Failed to get DT node\n");
+ return -ENODEV;
+ }
+
+ lpass = devm_kzalloc(dev, sizeof(*lpass), GFP_KERNEL);
+ if (!lpass)
+ return -ENOMEM;
+
+ lpass->pdev = pdev;
+ platform_set_drvdata(pdev, lpass);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ lpass->reg_sfr = devm_ioremap_resource(dev, res);
+ if (IS_ERR(lpass->reg_sfr))
+ return PTR_ERR(lpass->reg_sfr);
+
+ lpass->reg_pmu = syscon_regmap_lookup_by_phandle(dev->of_node,
+ "samsung,pmu-syscon");
+ if (IS_ERR(lpass->reg_pmu)) {
+ dev_err(dev, "Failed to lookup PMU regmap\n");
+ return PTR_ERR(lpass->reg_pmu);
+ }
+
+ lpass_enable(lpass);
+
+ return 0;
+}
+
+static int lpass_suspend(struct device *dev)
+{
+ struct lpass_info *lpass = dev_get_drvdata(dev);
+
+ lpass_disable(lpass);
+
+ return 0;
+}
+
+static int lpass_resume(struct device *dev)
+{
+ struct lpass_info *lpass = dev_get_drvdata(dev);
+
+ lpass_enable(lpass);
+
+ return 0;
+}
+
+static const struct of_device_id lpass_of_match[] = {
+ { .compatible = "samsung,exynos5433-lpass", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, lpass_of_match);
+
+static const struct dev_pm_ops lpass_pm_ops = {
+ .suspend = lpass_suspend,
+ .resume = lpass_resume,
+};
+
+static struct platform_driver lpass_driver = {
+ .driver = {
+ .name = "samsung-lpass",
+ .pm = &lpass_pm_ops,
+ .of_match_table = lpass_of_match,
+ },
+ .probe = lpass_probe,
+};
+
+module_platform_driver(lpass_driver);
+
+MODULE_AUTHOR("Inha Song <ideal.song at samsung.com>");
+MODULE_DESCRIPTION("Samsung Low Power Audio Subsystem (LPASS) driver");
+MODULE_LICENSE("GPL v2");
diff --git a/sound/soc/samsung/lpass.h b/sound/soc/samsung/lpass.h
new file mode 100644
index 0000000..59179d6
--- /dev/null
+++ b/sound/soc/samsung/lpass.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2015 - 2016 Samsung Electronics Co., Ltd.
+ * Inha Song <ideal.song at samsung.com>
+ *
+ * Low Power Audio Subsystem driver for Samsung Exynos
+ *
+ * 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; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+#ifndef SND_SOC_SAMSUNG_LPASS_H_
+#define SND_SOC_SAMSUNG_LPASS_H_
+
+/* SFR */
+#define SFR_LPASS_CORE_SW_RESET (0x08)
+#define SFR_LPASS_INTR_CA5_MASK (0x48)
+#define SFR_LPASS_INTR_CPU_MASK (0x58)
+
+/* SW_RESET */
+#define LPASS_SW_RESET_CA5 (1 << 0)
+#define LPASS_SW_RESET_SB (1 << 11)
+
+/* Interrupt mask */
+#define LPASS_INTR_APM (1 << 9)
+#define LPASS_INTR_MIF (1 << 8)
+#define LPASS_INTR_TIMER (1 << 7)
+#define LPASS_INTR_DMA (1 << 6)
+#define LPASS_INTR_GPIO (1 << 5)
+#define LPASS_INTR_I2S (1 << 4)
+#define LPASS_INTR_PCM (1 << 3)
+#define LPASS_INTR_SB (1 << 2)
+#define LPASS_INTR_UART (1 << 1)
+#define LPASS_INTR_SFR (1 << 0)
+
+/* SW Reset bit */
+enum {
+ SW_RESET_DMA = 0,
+ SW_RESET_MEM,
+ SW_RESET_TIMER,
+ SW_RESET_I2S = 8,
+ SW_RESET_PCM,
+ SW_RESET_UART,
+ SW_RESET_SLIMBUS,
+};
+
+#endif /* SND_SOC_SAMSUNG_LPASS_H_ */
--
1.9.1
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