ASoC: uniphier: add syscon property for UniPhier sound system

This patch adds syscon property for specifying soc-glue core.

Currently, soc-glue core is used for changing the state of S/PDIF
signal output pin to signal output state or Hi-Z state. After
resetting of SoC Hi-Z state is selected. This driver set to signal
output state when syscon property is available.
Signed-off-by: Katsuhiro Suzuki <suzuki.katsuhiro@socionext.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/uniphier/aio-core.c

@@ -83,6 +83,27 @@ u64 aio_rb_space_to_end(struct uniphier_aio_sub *sub)
 	return rb_space_to_end(sub->wr_offs, sub->rd_offs, sub->compr_bytes);
 }
 
+/**
+ * aio_iecout_set_enable - setup IEC output via SoC glue
+ * @chip: the AIO chip pointer
+ * @enable: false to stop the output, true to start
+ *
+ * Set enabled or disabled S/PDIF signal output to out of SoC via AOnIEC pins.
+ * This function need to call at driver startup.
+ *
+ * The regmap of SoC glue is specified by 'socionext,syscon' optional property
+ * of DT. This function has no effect if no property.
+ */
+void aio_iecout_set_enable(struct uniphier_aio_chip *chip, bool enable)
+{
+	struct regmap *r = chip->regmap_sg;
+
+	if (!r)
+		return;
+
+	regmap_write(r, SG_AOUTEN, (enable) ? ~0 : 0);
+}
+
 /**
  * aio_chip_set_pll - set frequency to audio PLL
  * @chip  : the AIO chip pointer

sound/soc/uniphier/aio-cpu.c

@@ -20,6 +20,7 @@
 #include <linux/clk.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>
@@ -387,6 +388,7 @@ int uniphier_aio_dai_probe(struct snd_soc_dai *dai)
 		sub->spec = spec;
 	}
 
+	aio_iecout_set_enable(aio->chip, true);
 	aio_chip_init(aio->chip);
 	aio->chip->active = 1;
 
@@ -431,6 +433,7 @@ int uniphier_aio_dai_resume(struct snd_soc_dai *dai)
 	if (ret)
 		goto err_out_clock;
 
+	aio_iecout_set_enable(aio->chip, true);
 	aio_chip_init(aio->chip);
 
 	for (i = 0; i < ARRAY_SIZE(aio->sub); i++) {
@@ -477,6 +480,14 @@ int uniphier_aio_probe(struct platform_device *pdev)
 	if (!chip->chip_spec)
 		return -EINVAL;
 
+	chip->regmap_sg = syscon_regmap_lookup_by_phandle(dev->of_node,
+							  "socionext,syscon");
+	if (IS_ERR(chip->regmap_sg)) {
+		if (PTR_ERR(chip->regmap_sg) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+		chip->regmap_sg = NULL;
+	}
+
 	chip->clk = devm_clk_get(dev, "aio");
 	if (IS_ERR(chip->clk))
 		return PTR_ERR(chip->clk);

sound/soc/uniphier/aio-reg.h

@@ -23,6 +23,9 @@
 
 #include <linux/bitops.h>
 
+/* soc-glue */
+#define SG_AOUTEN                       0x1c04
+
 /* SW view */
 #define A2CHNMAPCTR0(n)                 (0x00000 + 0x40 * (n))
 #define A2RBNMAPCTR0(n)                 (0x01000 + 0x40 * (n))

sound/soc/uniphier/aio.h

@@ -296,6 +296,7 @@ struct uniphier_aio_chip {
 	struct clk *clk;
 	struct reset_control *rst;
 	struct regmap *regmap;
+	struct regmap *regmap_sg;
 	int active;
 };
 
@@ -323,6 +324,7 @@ u64 aio_rbt_cnt_to_end(struct uniphier_aio_sub *sub);
 u64 aio_rb_space(struct uniphier_aio_sub *sub);
 u64 aio_rb_space_to_end(struct uniphier_aio_sub *sub);
 
+void aio_iecout_set_enable(struct uniphier_aio_chip *chip, bool enable);
 int aio_chip_set_pll(struct uniphier_aio_chip *chip, int pll_id,
 		     unsigned int freq);
 void aio_chip_init(struct uniphier_aio_chip *chip);