rockchip: Add an I2S driver

Add a driver for I2S which allows audio data to be sent from the SoC to
the audio codec. The sample rate and other settings are hard-coded for now
as there is no suitable device-tree binding available.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>

diff --git a/drivers/sound/Kconfig b/drivers/sound/Kconfig
index c0d97cc..22e3796 100644 (file)
--- a/drivers/sound/Kconfig
+++ b/drivers/sound/Kconfig
@@ -21,6 +21,15 @@ config I2S
          I2S. It calls either of the two supported codecs (no use is made
          of driver model at present).
 
+config I2S_ROCKCHIP
+       bool "Enable I2S support for Rockchip SoCs"
+       depends on I2S
+       help
+         Rockchip SoCs support an I2S interface for sending audio data to an
+         audio codec. This option enables support for this, using one of the
+         available audio codec drivers. This driver does not make use of
+         DMA, but writes each word directly to the hardware.
+
 config I2S_SAMSUNG
        bool "Enable I2C support for Samsung SoCs"
        depends on SOUND

diff --git a/drivers/sound/Makefile b/drivers/sound/Makefile
index 1de4346..91f255b 100644 (file)
--- a/drivers/sound/Makefile
+++ b/drivers/sound/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_SOUND)     += i2s-uclass.o
 obj-$(CONFIG_SOUND)    += sound-uclass.o
 obj-$(CONFIG_I2S_SAMSUNG)      += samsung-i2s.o
 obj-$(CONFIG_SOUND_SANDBOX)    += sandbox.o
+obj-$(CONFIG_I2S_ROCKCHIP)     += rockchip_i2s.o
 obj-$(CONFIG_I2S_SAMSUNG)      += samsung_sound.o
 obj-$(CONFIG_SOUND_WM8994)     += wm8994.o
 obj-$(CONFIG_SOUND_MAX98090)   += max98090.o maxim_codec.o

diff --git a/drivers/sound/rockchip_i2s.c b/drivers/sound/rockchip_i2s.c
new file mode 100644 (file)
index 0000000..e5df8ca
--- /dev/null
+++ b/drivers/sound/rockchip_i2s.c
@@ -0,0 +1,149 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2018 Google LLC
+ * Copyright 2014 Rockchip Electronics Co., Ltd.
+ * Taken from dc i2s/rockchip.c
+ */
+
+#define LOG_CATEGORY UCLASS_I2S
+
+#include <common.h>
+#include <dm.h>
+#include <i2s.h>
+#include <sound.h>
+#include <asm/io.h>
+
+struct rk_i2s_regs {
+       u32 txcr;               /* I2S_TXCR, 0x00 */
+       u32 rxcr;               /* I2S_RXCR, 0x04 */
+       u32 ckr;                /* I2S_CKR, 0x08 */
+       u32 fifolr;             /* I2S_FIFOLR, 0x0C */
+       u32 dmacr;              /* I2S_DMACR, 0x10 */
+       u32 intcr;              /* I2S_INTCR, 0x14 */
+       u32 intsr;              /* I2S_INTSR, 0x18 */
+       u32 xfer;               /* I2S_XFER, 0x1C */
+       u32 clr;                /* I2S_CLR, 0x20 */
+       u32 txdr;               /* I2S_TXDR, 0x24 */
+       u32 rxdr;               /* I2S_RXDR, 0x28 */
+};
+
+enum {
+       /* I2S_XFER */
+       I2S_RX_TRAN_BIT         = BIT(1),
+       I2S_TX_TRAN_BIT         = BIT(0),
+       I2S_TRAN_MASK           = 3 << 0,
+
+       /* I2S_TXCKR */
+       I2S_MCLK_DIV_SHIFT      = 16,
+       I2S_MCLK_DIV_MASK       = (0xff << I2S_MCLK_DIV_SHIFT),
+
+       I2S_RX_SCLK_DIV_SHIFT   = 8,
+       I2S_RX_SCLK_DIV_MASK    = 0xff << I2S_RX_SCLK_DIV_SHIFT,
+       I2S_TX_SCLK_DIV_SHIFT   = 0,
+       I2S_TX_SCLK_DIV_MASK    = 0xff << I2S_TX_SCLK_DIV_SHIFT,
+
+       I2S_DATA_WIDTH_SHIFT    = 0,
+       I2S_DATA_WIDTH_MASK     = 0x1f << I2S_DATA_WIDTH_SHIFT,
+};
+
+static int rockchip_i2s_init(struct i2s_uc_priv *priv)
+{
+       struct rk_i2s_regs *regs = (struct rk_i2s_regs *)priv->base_address;
+       u32 bps = priv->bitspersample;
+       u32 lrf = priv->rfs;
+       u32 chn = priv->channels;
+       u32 mode = 0;
+
+       clrbits_le32(&regs->xfer, I2S_TX_TRAN_BIT);
+       mode = readl(&regs->txcr) & ~0x1f;
+       switch (priv->bitspersample) {
+       case 16:
+       case 24:
+               mode |= (priv->bitspersample - 1) << I2S_DATA_WIDTH_SHIFT;
+               break;
+       default:
+               log_err("Invalid sample size input %d\n", priv->bitspersample);
+               return -EINVAL;
+       }
+       writel(mode, &regs->txcr);
+
+       mode = readl(&regs->ckr) & ~I2S_MCLK_DIV_MASK;
+       mode |= (lrf / (bps * chn) - 1) << I2S_MCLK_DIV_SHIFT;
+
+       mode &= ~I2S_TX_SCLK_DIV_MASK;
+       mode |= (priv->bitspersample * priv->channels - 1) <<
+                        I2S_TX_SCLK_DIV_SHIFT;
+       writel(mode, &regs->ckr);
+
+       return 0;
+}
+
+static int i2s_send_data(struct rk_i2s_regs *regs, u32 *data, uint length)
+{
+       for (int i = 0; i < min(32u, length); i++)
+               writel(*data++, &regs->txdr);
+
+       length -= min(32u, length);
+
+       /* enable both tx and rx */
+       setbits_le32(&regs->xfer, I2S_TRAN_MASK);
+       while (length) {
+               if ((readl(&regs->fifolr) & 0x3f) < 0x20) {
+                       writel(*data++, &regs->txdr);
+                       length--;
+               }
+       }
+       while (readl(&regs->fifolr) & 0x3f)
+               /* wait until FIFO empty */;
+       clrbits_le32(&regs->xfer, I2S_TRAN_MASK);
+       writel(0, &regs->clr);
+
+       return 0;
+}
+
+static int rockchip_i2s_tx_data(struct udevice *dev, void *data, uint data_size)
+{
+       struct i2s_uc_priv *priv = dev_get_uclass_priv(dev);
+       struct rk_i2s_regs *regs = (struct rk_i2s_regs *)priv->base_address;
+
+       return i2s_send_data(regs, data, data_size / sizeof(u32));
+}
+
+static int rockchip_i2s_probe(struct udevice *dev)
+{
+       struct i2s_uc_priv *priv = dev_get_uclass_priv(dev);
+       ulong base;
+
+       base = dev_read_addr(dev);
+       if (base == FDT_ADDR_T_NONE) {
+               log_debug("Missing i2s base\n");
+               return -EINVAL;
+       }
+       priv->base_address = base;
+       priv->id = 1;
+       priv->audio_pll_clk = 4800000;
+       priv->samplingrate = 48000;
+       priv->bitspersample = 16;
+       priv->channels = 2;
+       priv->rfs = 256;
+       priv->bfs = 32;
+
+       return rockchip_i2s_init(priv);
+}
+
+static const struct i2s_ops rockchip_i2s_ops = {
+       .tx_data        = rockchip_i2s_tx_data,
+};
+
+static const struct udevice_id rockchip_i2s_ids[] = {
+       { .compatible = "rockchip,rk3288-i2s" },
+       { }
+};
+
+U_BOOT_DRIVER(rockchip_i2s) = {
+       .name           = "rockchip_i2s",
+       .id             = UCLASS_I2S,
+       .of_match       = rockchip_i2s_ids,
+       .probe          = rockchip_i2s_probe,
+       .ops            = &rockchip_i2s_ops,
+};