ASoC: simple-card: add Device Tree support

Support for loading the simple-card module via DeviceTree.
It requests CPU/CODEC information.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

2 files changed, 218 insertions, 6 deletions

diff --git a/Documentation/devicetree/bindings/sound/simple-card.txt b/Documentation/devicetree/bindings/sound/simple-card.txt
new file mode 100644
index 000000000000..769a346f890c
--- /dev/null
+++ b/Documentation/devicetree/bindings/sound/simple-card.txt
@@ -0,0 +1,68 @@
+Simple-Card:
+
+Simple-Card specifies audio DAI connection of SoC <-> codec.
+
+Required properties:
+
+- compatible                            : "simple-audio-card"
+
+Optional properties:
+
+- simple-audio-card,format              : CPU/CODEC common audio format.
+                                        "i2s", "right_j", "left_j" , "dsp_a"
+                                        "dsp_b", "ac97", "pdm", "msb", "lsb"
+Required subnodes:
+
+- simple-audio-card,cpu                 : CPU   sub-node
+- simple-audio-card,codec               : CODEC sub-node
+
+Required CPU/CODEC subnodes properties:
+
+- sound-dai                             : phandle and port of CPU/CODEC
+
+Optional CPU/CODEC subnodes properties:
+
+- format                                : CPU/CODEC specific audio format if needed.
+                                          see simple-audio-card,format
+- frame-master                          : bool property. add this if subnode is frame master
+- bitclock-master                       : bool property. add this if subnode is bitclock master
+- bitclock-inversion                    : bool property. add this if subnode has clock inversion
+- frame-inversion                       : bool property. add this if subnode has frame inversion
+- clocks / system-clock-frequency       : specify subnode's clock if needed.
+                                          it can be specified via "clocks" if system has
+                                          clock node (= common clock), or "system-clock-frequency"
+                                          (if system doens't support common clock)
+
+Example:
+
+sound {
+        compatible = "simple-audio-card";
+        simple-audio-card,format = "left_j";
+
+        simple-audio-card,cpu {
+                sound-dai = <&sh_fsi2 0>;
+        };
+
+        simple-audio-card,codec {
+                sound-dai = <&ak4648>;
+                bitclock-master;
+                frame-master;
+                clocks = <&osc>;
+        };
+};
+
+&i2c0 {
+        ak4648: ak4648@12 {
+                #sound-dai-cells = <0>;
+                compatible = "asahi-kasei,ak4648";
+                reg = <0x12>;
+        };
+};
+
+sh_fsi2: sh_fsi2@ec230000 {
+        #sound-dai-cells = <1>;
+        compatible = "renesas,sh_fsi2";
+        reg = <0xec230000 0x400>;
+        interrupt-parent = <&gic>;
+        interrupts = <0 146 0x4>;
+};
diff --git a/sound/soc/generic/simple-card.c b/sound/soc/generic/simple-card.c
index b2fbb7075a6c..7a9b6b4898c0 100644
--- a/sound/soc/generic/simple-card.c
+++ b/sound/soc/generic/simple-card.c
@@ -8,7 +8,8 @@
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */
-
+#include <linux/clk.h>
+#include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/module.h>
 #include <sound/simple_card.h>
@@ -57,11 +58,144 @@ static int asoc_simple_card_dai_init(struct snd_soc_pcm_runtime *rtd)
         return 0;
 }
 
+static int
+asoc_simple_card_sub_parse_of(struct device_node *np,
+                              struct asoc_simple_dai *dai,
+                              struct device_node **node)
+{
+        struct clk *clk;
+        int ret;
+
+        /*
+         * get node via "sound-dai = <&phandle port>"
+         * it will be used as xxx_of_node on soc_bind_dai_link()
+         */
+        *node = of_parse_phandle(np, "sound-dai", 0);
+        if (!*node)
+                return -ENODEV;
+
+        /* get dai->name */
+        ret = snd_soc_of_get_dai_name(np, &dai->name);
+        if (ret < 0)
+                goto parse_error;
+
+        /*
+         * bitclock-inversion, frame-inversion
+         * bitclock-master,    frame-master
+         * and specific "format" if it has
+         */
+        dai->fmt = snd_soc_of_parse_daifmt(np, NULL);
+
+        /*
+         * dai->sysclk come from
+         *  "clocks = <&xxx>" (if system has common clock)
+         *  or "system-clock-frequency = <xxx>"
+         */
+        clk = of_clk_get(np, 0);
+        if (IS_ERR(clk))
+                of_property_read_u32(np,
+                                     "system-clock-frequency",
+                                     &dai->sysclk);
+        else
+                dai->sysclk = clk_get_rate(clk);
+
+        ret = 0;
+
+parse_error:
+        of_node_put(*node);
+
+        return ret;
+}
+
+static int asoc_simple_card_parse_of(struct device_node *node,
+                                     struct asoc_simple_card_info *info,
+                                     struct device *dev,
+                                     struct device_node **of_cpu,
+                                     struct device_node **of_codec,
+                                     struct device_node **of_platform)
+{
+        struct device_node *np;
+        char *name;
+        int ret = 0;
+
+        /* get CPU/CODEC common format via simple-audio-card,format */
+        info->daifmt = snd_soc_of_parse_daifmt(node, "simple-audio-card,") &
+                (SND_SOC_DAIFMT_FORMAT_MASK | SND_SOC_DAIFMT_INV_MASK);
+
+        /* CPU sub-node */
+        ret = -EINVAL;
+        np = of_get_child_by_name(node, "simple-audio-card,cpu");
+        if (np)
+                ret = asoc_simple_card_sub_parse_of(np,
+                                                  &info->cpu_dai,
+                                                  of_cpu);
+        if (ret < 0)
+                return ret;
+
+        /* CODEC sub-node */
+        ret = -EINVAL;
+        np = of_get_child_by_name(node, "simple-audio-card,codec");
+        if (np)
+                ret = asoc_simple_card_sub_parse_of(np,
+                                                  &info->codec_dai,
+                                                  of_codec);
+        if (ret < 0)
+                return ret;
+
+        /* card name is created from CPU/CODEC dai name */
+        name = devm_kzalloc(dev,
+                            strlen(info->cpu_dai.name)   +
+                            strlen(info->codec_dai.name) + 2,
+                            GFP_KERNEL);
+        sprintf(name, "%s-%s", info->cpu_dai.name, info->codec_dai.name);
+        info->name = info->card = name;
+
+        /* simple-card assumes platform == cpu */
+        *of_platform = *of_cpu;
+
+        dev_dbg(dev, "card-name : %s\n", info->card);
+        dev_dbg(dev, "platform : %04x\n", info->daifmt);
+        dev_dbg(dev, "cpu : %s / %04x / %d\n",