x86: sound: Add support for broadwell I2S

I2S is used to send digital audio data to an audio codec. Add support for
this on broadwell.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/sound/broadwell_i2s.c b/drivers/sound/broadwell_i2s.c
new file mode 100644
index 0000000..998792b
--- /dev/null
+++ b/drivers/sound/broadwell_i2s.c
@@ -0,0 +1,306 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Intel Broadwell I2S driver
+ *
+ * Copyright 2019 Google LLC
+ *
+ * Modified from dc i2s/broadwell/broadwell.c
+ */
+
+#define LOG_CATEGORY UCLASS_I2S
+
+#include <common.h>
+#include <dm.h>
+#include <i2s.h>
+#include <asm/io.h>
+#include "broadwell_i2s.h"
+
+enum {
+	BDW_SHIM_START_ADDRESS = 0xfb000,
+	BDW_SSP0_START_ADDRESS = 0xfc000,
+	BDW_SSP1_START_ADDRESS = 0xfd000,
+};
+
+struct broadwell_i2s_priv {
+	enum frame_sync_rel_timing_t rel_timing;
+	enum frame_sync_pol_t sfrm_polarity;
+	enum end_transfer_state_t end_transfer_state;
+	enum clock_mode_t sclk_mode;
+	uint sclk_dummy_stop;	/* 0-31 */
+	uint sclk_frame_width;	/* 1-38 */
+	struct i2s_shim_regs *shim;
+	struct broadwell_i2s_regs *regs;
+};
+
+static void init_shim_csr(struct broadwell_i2s_priv *priv)
+{
+	/*
+	 * Select SSP clock
+	 * Turn off low power clock
+	 * Set PIO mode
+	 * Stall DSP core
+	 */
+	clrsetbits_le32(&priv->shim->csr,
+			SHIM_CS_S0IOCS | SHIM_CS_LPCS | SHIM_CS_DCS_MASK,
+			SHIM_CS_S1IOCS | SHIM_CS_SBCS_SSP1_24MHZ |
+			SHIM_CS_SBCS_SSP0_24MHZ | SHIM_CS_SDPM_PIO_SSP1 |
+			SHIM_CS_SDPM_PIO_SSP0 | SHIM_CS_STALL |
+			SHIM_CS_DCS_DSP32_AF32);
+}
+
+static void init_shim_clkctl(struct i2s_uc_priv *uc_priv,
+			     struct broadwell_i2s_priv *priv)
+{
+	u32 clkctl = readl(&priv->shim->clkctl);
+
+	/* Set 24Mhz mclk, prevent local clock gating, enable SSP0 clock */
+	clkctl &= SHIM_CLKCTL_RESERVED;
+	clkctl |= SHIM_CLKCTL_MCLK_24MHZ | SHIM_CLKCTL_DCPLCG;
+
+	/* Enable requested SSP interface */
+	if (uc_priv->id)
+		clkctl |= SHIM_CLKCTL_SCOE_SSP1 | SHIM_CLKCTL_SFLCGB_SSP1_CGD;
+	else
+		clkctl |= SHIM_CLKCTL_SCOE_SSP0 | SHIM_CLKCTL_SFLCGB_SSP0_CGD;
+
+	writel(clkctl, &priv->shim->clkctl);
+}
+
+static void init_sscr0(struct i2s_uc_priv *uc_priv,
+		       struct broadwell_i2s_priv *priv)
+{
+	u32 sscr0;
+	uint scale;
+
+	/* Set data size based on BPS */
+	if (uc_priv->bitspersample > 16)
+		sscr0 = (uc_priv->bitspersample - 16 - 1) << SSP_SSC0_DSS_SHIFT
+			 | SSP_SSC0_EDSS;
+	else
+		sscr0 = (uc_priv->bitspersample - 1) << SSP_SSC0_DSS_SHIFT;
+
+	/* Set network mode, Stereo PSP frame format */
+	sscr0 |= SSP_SSC0_MODE_NETWORK |
+		SSP_SSC0_FRDC_STEREO |
+		SSP_SSC0_FRF_PSP |
+		SSP_SSC0_TIM |
+		SSP_SSC0_RIM |
+		SSP_SSC0_ECS_PCH |
+		SSP_SSC0_NCS_PCH |
+		SSP_SSC0_ACS_PCH;
+
+	/* Scale 24MHz MCLK */
+	scale = uc_priv->audio_pll_clk / uc_priv->samplingrate / uc_priv->bfs;
+	sscr0 |= scale << SSP_SSC0_SCR_SHIFT;
+
+	writel(sscr0, &priv->regs->sscr0);
+}
+
+static void init_sscr1(struct broadwell_i2s_priv *priv)
+{
+	u32 sscr1 = readl(&priv->regs->sscr1);
+
+	sscr1 &= SSP_SSC1_RESERVED;
+
+	/* Set as I2S master */
+	sscr1 |= SSP_SSC1_SCLKDIR_MASTER | SSP_SSC1_SCLKDIR_MASTER;
+
+	/* Enable TXD tristate behavior for PCH */
+	sscr1 |= SSP_SSC1_TTELP | SSP_SSC1_TTE;
+
+	/* Disable DMA Tx/Rx service request */
+	sscr1 |= SSP_SSC1_TSRE | SSP_SSC1_RSRE;
+
+	/* Clock on during transfer */
+	sscr1 |= SSP_SSC1_SCFR;
+
+	/* Set FIFO thresholds */
+	sscr1 |= SSP_FIFO_SIZE << SSP_SSC1_RFT_SHIFT;
+	sscr1 |= SSP_FIFO_SIZE << SSP_SSC1_TFT_SHIFT;
+
+	/* Disable interrupts */
+	sscr1 &= ~(SSP_SSC1_EBCEI | SSP_SSC1_TINTE | SSP_SSC1_PINTE);
+	sscr1 &= ~(SSP_SSC1_LBM | SSP_SSC1_RWOT);
+
+	writel(sscr1, &priv->regs->sscr1);
+}
+
+static void init_sspsp(struct broadwell_i2s_priv *priv)
+{
+	u32 sspsp = readl(&priv->regs->sspsp);
+
+	sspsp &= SSP_PSP_RESERVED;
+	sspsp |= priv->sclk_mode << SSP_PSP_SCMODE_SHIFT;
+	sspsp |= (priv->sclk_dummy_stop << SSP_PSP_DMYSTOP_SHIFT) &
+			SSP_PSP_DMYSTOP_MASK;
+	sspsp |= (priv->sclk_dummy_stop >> 2 << SSP_PSP_EDYMSTOP_SHIFT) &
+			SSP_PSP_EDMYSTOP_MASK;
+	sspsp |= priv->sclk_frame_width << SSP_PSP_SFRMWDTH_SHIFT;
+
+	/* Frame Sync Relative Timing */
+	if (priv->rel_timing == NEXT_FRMS_AFTER_END_OF_T4)
+		sspsp |= SSP_PSP_FSRT;
+	else
+		sspsp &= ~SSP_PSP_FSRT;
+
+	/* Serial Frame Polarity */
+	if (priv->sfrm_polarity == SSP_FRMS_ACTIVE_HIGH)
+		sspsp |= SSP_PSP_SFRMP;
+	else
+		sspsp &= ~SSP_PSP_SFRMP;
+
+	/* End Data Transfer State */
+	if (priv->end_transfer_state == SSP_END_TRANSFER_STATE_LOW)
+		sspsp &= ~SSP_PSP_ETDS;
+	else
+		sspsp |= SSP_PSP_ETDS;
+
+	writel(sspsp, &priv->regs->sspsp);
+}
+
+static void init_ssp_time_slot(struct broadwell_i2s_priv *priv)
+{
+	writel(3, &priv->regs->sstsa);
+	writel(3, &priv->regs->ssrsa);
+}
+
+static int bdw_i2s_init(struct udevice *dev)
+{
+	struct i2s_uc_priv *uc_priv = dev_get_uclass_priv(dev);
+	struct broadwell_i2s_priv *priv = dev_get_priv(dev);
+
+	init_shim_csr(priv);
+	init_shim_clkctl(uc_priv, priv);
+	init_sscr0(uc_priv, priv);
+	init_sscr1(priv);
+	init_sspsp(priv);
+	init_ssp_time_slot(priv);
+
+	return 0;
+}
+
+static void bdw_i2s_enable(struct broadwell_i2s_priv *priv)
+{
+	setbits_le32(&priv->regs->sscr0, SSP_SSC0_SSE);
+	setbits_le32(&priv->regs->sstsa, SSP_SSTSA_EN);
+}
+
+static void bdw_i2s_disable(struct broadwell_i2s_priv *priv)
+{
+	clrbits_le32(&priv->regs->sstsa, SSP_SSTSA_EN);
+	clrbits_le32(&priv->regs->sstsa, SSP_SSTSA_EN);
+}
+
+static int broadwell_i2s_tx_data(struct udevice *dev, void *data,
+				 uint data_size)
+{
+	struct broadwell_i2s_priv *priv = dev_get_priv(dev);
+	u32 *ptr = data;
+
+	log_debug("data=%p, data_size=%x\n", data, data_size);
+	if (data_size < SSP_FIFO_SIZE) {
+		log_err("Invalid I2S data size\n");
+		return -ENODATA;
+	}
+
+	/* Enable I2S interface */
+	bdw_i2s_enable(priv);
+
+	/* Transfer data */
+	while (data_size > 0) {
+		ulong start = timer_get_us() + 100000;
+
+		/* Write data if transmit FIFO has room */
+		if (readl(&priv->regs->sssr) & SSP_SSS_TNF) {
+			writel(*ptr++, &priv->regs->ssdr);
+			data_size -= sizeof(*ptr);
+		} else {
+			if ((long)(timer_get_us() - start) > 0) {
+				/* Disable I2S interface */
+				bdw_i2s_disable(priv);
+				log_debug("I2S Transfer Timeout\n");
+				return -ETIMEDOUT;
+			}
+		}
+	}
+
+	/* Disable I2S interface */
+	bdw_i2s_disable(priv);
+	log_debug("done\n");
+
+	return 0;
+}
+
+static int broadwell_i2s_probe(struct udevice *dev)
+{
+	struct i2s_uc_priv *uc_priv = dev_get_uclass_priv(dev);
+	struct broadwell_i2s_priv *priv = dev_get_priv(dev);
+	struct udevice *adsp = dev_get_parent(dev);
+	u32 bar0, offset;
+	int ret;
+
+	bar0 = dm_pci_read_bar32(adsp, 0);
+	if (!bar0) {
+		log_debug("Cannot read adsp bar0\n");
+		return -EINVAL;
+	}
+	offset = dev_read_addr_index(dev, 0);
+	if (offset == FDT_ADDR_T_NONE) {
+		log_debug("Cannot read address index 0\n");
+		return -EINVAL;
+	}
+	uc_priv->base_address = bar0 + offset;
+
+	/*
+	 * Hard-code these values. If other settings are required we can add
+	 * this to the device tree.
+	 */
+	uc_priv->rfs = 64;
+	uc_priv->bfs = 32;
+	uc_priv->audio_pll_clk = 24 * 1000 * 1000;
+	uc_priv->samplingrate = 48000;
+	uc_priv->bitspersample = 16;
+	uc_priv->channels = 2;
+	uc_priv->id = 0;
+
+	priv->shim = (struct i2s_shim_regs *)uc_priv->base_address;
+	priv->sfrm_polarity = SSP_FRMS_ACTIVE_LOW;
+	priv->end_transfer_state = SSP_END_TRANSFER_STATE_LOW;
+	priv->sclk_mode = SCLK_MODE_DDF_DSR_ISL;
+	priv->rel_timing = NEXT_FRMS_WITH_LSB_PREVIOUS_FRM;
+	priv->sclk_dummy_stop = 0;
+	priv->sclk_frame_width = 31;
+
+	offset = dev_read_addr_index(dev, 1 + uc_priv->id);
+	if (offset == FDT_ADDR_T_NONE) {
+		log_debug("Cannot read address index %d\n", 1 + uc_priv->id);
+		return -EINVAL;
+	}
+	log_debug("bar0=%x, uc_priv->base_address=%x, offset=%x\n", bar0,
+		  uc_priv->base_address, offset);
+	priv->regs = (struct broadwell_i2s_regs *)(bar0 + offset);
+
+	ret = bdw_i2s_init(dev);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static const struct i2s_ops broadwell_i2s_ops = {
+	.tx_data	= broadwell_i2s_tx_data,
+};
+
+static const struct udevice_id broadwell_i2s_ids[] = {
+	{ .compatible = "intel,broadwell-i2s" },
+	{ }
+};
+
+U_BOOT_DRIVER(broadwell_i2s) = {
+	.name		= "broadwell_i2s",
+	.id		= UCLASS_I2S,
+	.of_match	= broadwell_i2s_ids,
+	.probe		= broadwell_i2s_probe,
+	.ops		= &broadwell_i2s_ops,
+	.priv_auto_alloc_size	= sizeof(struct broadwell_i2s_priv),
+};