ASoC: fsl_sai_clk: clock driver for SAI

This adds a clock driver to use the bitclock (TX_BCLK) as a master
clock.

3 files changed, 204 insertions, 1 deletions

diff --git a/sound/soc/fsl/Makefile b/sound/soc/fsl/Makefile
index d28dc25c9375..8e0fe108911c 100644
--- a/sound/soc/fsl/Makefile
+++ b/sound/soc/fsl/Makefile
@@ -13,7 +13,7 @@ obj-$(CONFIG_SND_SOC_P1022_RDK) += snd-soc-p1022-rdk.o
 # Freescale SSI/DMA/SAI/SPDIF Support
 snd-soc-fsl-asoc-card-objs := fsl-asoc-card.o
 snd-soc-fsl-asrc-objs := fsl_asrc.o fsl_asrc_dma.o
-snd-soc-fsl-sai-objs := fsl_sai.o
+snd-soc-fsl-sai-objs := fsl_sai.o fsl_sai_clk.o
 snd-soc-fsl-ssi-y := fsl_ssi.o
 snd-soc-fsl-ssi-$(CONFIG_DEBUG_FS) += fsl_ssi_dbg.o
 snd-soc-fsl-spdif-objs := fsl_spdif.o
diff --git a/sound/soc/fsl/fsl_sai.h b/sound/soc/fsl/fsl_sai.h
index 34667209b607..d82a096f9e1c 100644
--- a/sound/soc/fsl/fsl_sai.h
+++ b/sound/soc/fsl/fsl_sai.h
@@ -47,6 +47,7 @@
 
 /* SAI Transmit/Recieve Control Register */
 #define FSL_SAI_CSR_TERE	BIT(31)
+#define FSL_SAI_CSR_BCE		BIT(28)
 #define FSL_SAI_CSR_FR		BIT(25)
 #define FSL_SAI_CSR_SR		BIT(24)
 #define FSL_SAI_CSR_xF_SHIFT	16
@@ -71,7 +72,9 @@
 #define FSL_SAI_CR1_RFW_MASK	0x1f
 
 /* SAI Transmit and Recieve Configuration 2 Register */
+#define FSL_SAI_CR2_SYNC_MASK	(0x3 << 30)
 #define FSL_SAI_CR2_SYNC	BIT(30)
+#define FSL_SAI_CR2_BCS		BIT(29)
 #define FSL_SAI_CR2_MSEL_MASK	(0xff << 26)
 #define FSL_SAI_CR2_MSEL_BUS	0
 #define FSL_SAI_CR2_MSEL_MCLK1	BIT(26)
@@ -79,6 +82,8 @@
 #define FSL_SAI_CR2_MSEL_MCLK3	(BIT(26) | BIT(27))
 #define FSL_SAI_CR2_BCP		BIT(25)
 #define FSL_SAI_CR2_BCD_MSTR	BIT(24)
+#define FSL_SAI_CR2_DIV_MASK	0xff
+#define FSL_SAI_CR2_DIV(x)	(x & 0xff)
 
 /* SAI Transmit and Recieve Configuration 3 Register */
 #define FSL_SAI_CR3_TRCE	BIT(16)
diff --git a/sound/soc/fsl/fsl_sai_clk.c b/sound/soc/fsl/fsl_sai_clk.c
new file mode 100644
index 000000000000..bc593d6225ae
--- /dev/null
+++ b/sound/soc/fsl/fsl_sai_clk.c
@@ -0,0 +1,198 @@
+/*
+ * Freescale ALSA SoC Digital Audio Interface (SAI) driver.
+ *
+ * Copyright 2012-2013 Freescale Semiconductor, Inc.
+ *
+ * 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/clk.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <sound/core.h>
+#include <sound/dmaengine_pcm.h>
+#include <sound/pcm_params.h>
+
+#include "fsl_sai.h"
+
+static bool fsl_sai_readable_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case FSL_SAI_TCSR:
+	case FSL_SAI_TCR1:
+	case FSL_SAI_TCR2:
+	case FSL_SAI_TCR3:
+	case FSL_SAI_TCR4:
+	case FSL_SAI_TCR5:
+	case FSL_SAI_TFR:
+	case FSL_SAI_TMR:
+	case FSL_SAI_RCSR:
+	case FSL_SAI_RCR1:
+	case FSL_SAI_RCR2:
+	case FSL_SAI_RCR3:
+	case FSL_SAI_RCR4:
+	case FSL_SAI_RCR5:
+	case FSL_SAI_RDR:
+	case FSL_SAI_RFR:
+	case FSL_SAI_RMR:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool fsl_sai_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case FSL_SAI_TFR:
+	case FSL_SAI_RFR:
+	case FSL_SAI_TDR:
+	case FSL_SAI_RDR:
+		return true;
+	default:
+		return false;
+	}
+
+}
+
+static bool fsl_sai_writeable_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case FSL_SAI_TCSR:
+	case FSL_SAI_TCR1:
+	case FSL_SAI_TCR2:
+	case FSL_SAI_TCR3:
+	case FSL_SAI_TCR4:
+	case FSL_SAI_TCR5:
+	case FSL_SAI_TDR:
+	case FSL_SAI_TMR:
+	case FSL_SAI_RCSR:
+	case FSL_SAI_RCR1:
+	case FSL_SAI_RCR2:
+	case FSL_SAI_RCR3:
+	case FSL_SAI_RCR4:
+	case FSL_SAI_RCR5:
+	case FSL_SAI_RMR:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static struct regmap_config fsl_sai_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+
+	.max_register = FSL_SAI_RMR,
+	.readable_reg = fsl_sai_readable_reg,
+	.volatile_reg = fsl_sai_volatile_reg,
+	.writeable_reg = fsl_sai_writeable_reg,
+};
+
+static int fsl_sai_clk_probe(struct platform_device *pdev)
+{
+	struct fsl_sai *sai;
+	struct resource *res;
+	void __iomem *base;
+	char tmp[8];
+	int i;
+
+	sai = devm_kzalloc(&pdev->dev, sizeof(*sai), GFP_KERNEL);
+	if (!sai)
+		return -ENOMEM;
+
+	sai->pdev = pdev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	sai->regmap = devm_regmap_init_mmio_clk(&pdev->dev,
+			"bus", base, &fsl_sai_regmap_config);
+
+	/* Compatible with old DTB cases */
+	if (IS_ERR(sai->regmap))
+		sai->regmap = devm_regmap_init_mmio_clk(&pdev->dev,
+				"sai", base, &fsl_sai_regmap_config);
+	if (IS_ERR(sai->regmap)) {
+		dev_err(&pdev->dev, "regmap init failed\n");
+		return PTR_ERR(sai->regmap);
+	}
+
+	/* No error out for old DTB cases but only mark the clock NULL */
+	sai->bus_clk = devm_clk_get(&pdev->dev, "bus");
+	if (IS_ERR(sai->bus_clk)) {
+		dev_err(&pdev->dev, "failed to get bus clock: %ld\n",
+				PTR_ERR(sai->bus_clk));
+		sai->bus_clk = NULL;
+	}
+
+	for (i = 0; i < FSL_SAI_MCLK_MAX; i++) {
+		sprintf(tmp, "mclk%d", i + 1);
+		sai->mclk_clk[i] = devm_clk_get(&pdev->dev, tmp);
+		if (IS_ERR(sai->mclk_clk[i])) {
+			dev_err(&pdev->dev, "failed to get mclk%d clock: %ld\n",
+					i + 1, PTR_ERR(sai->mclk_clk[i]));
+			sai->mclk_clk[i] = NULL;
+		}
+	}
+
+	/* configure AC97 master clock */
+	regmap_update_bits(sai->regmap, FSL_SAI_TCR2, FSL_SAI_CR2_SYNC,
+			   ~FSL_SAI_CR2_SYNC);
+
+
+	/* asynchronous aka independent operation */
+	regmap_update_bits(sai->regmap, FSL_SAI_TCR2, FSL_SAI_CR2_SYNC_MASK, 0);
+
+	/* Bit clock not swapped */
+	regmap_update_bits(sai->regmap, FSL_SAI_TCR2, FSL_SAI_CR2_BCS, 0);
+
+	/* Clock selected by CCM_CSCMR1[SAIn_CLK_SEL] */
+	regmap_update_bits(sai->regmap, FSL_SAI_TCR2, FSL_SAI_CR2_MSEL_MASK,
+			   FSL_SAI_CR2_MSEL_MCLK1);
+
+	/* Bitclock is generated internally (master mode) */
+	regmap_update_bits(sai->regmap, FSL_SAI_TCR2, FSL_SAI_CR2_BCD_MSTR,
+			   FSL_SAI_CR2_BCD_MSTR);
+
+	/* Divide by 6 */
+	regmap_update_bits(sai->regmap, FSL_SAI_TCR2, FSL_SAI_CR2_DIV_MASK,
+			   FSL_SAI_CR2_DIV(2));
+
+	/* enable AC97 master clock */
+	regmap_update_bits(sai->regmap, FSL_SAI_TCSR, FSL_SAI_CSR_BCE,
+			   FSL_SAI_CSR_BCE);
+
+	return clk_prepare_enable(sai->bus_clk);
+}
+
+static const struct of_device_id fsl_sai_ids[] = {
+	{ .compatible = "fsl,vf610-sai-clk", },
+	{ /* sentinel */ }
+};
+
+static struct platform_driver fsl_sai_driver = {
+	.probe = fsl_sai_clk_probe,
+	.driver = {
+		.name = "fsl-sai-clk",
+		.owner = THIS_MODULE,
+		.of_match_table = fsl_sai_ids,
+	},
+};
+module_platform_driver(fsl_sai_driver);
+
+MODULE_DESCRIPTION("Freescale SoC SAI as clock generator");
+MODULE_AUTHOR("Stefan Agner, <stefan.agner@toradex.com>");
+MODULE_ALIAS("platform:fsl-sai-clk");
+MODULE_LICENSE("GPLv2");