From 873b86c8a45dc6cd66c7523d42562639cceabb40 Mon Sep 17 00:00:00 2001
From: Sugar Zhang <sugar.zhang@rock-chips.com>
Date: Sun, 15 Oct 2023 11:26:32 +0800
Subject: [PATCH] ASoC: rockchip: pdm: Add support for CLK-ALWAYS-ON quirks

This patch add support for keeping PDM-CLK always on.

Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com>
Change-Id: Ibe5f660b52de6dba493a0046f89e4b2af1b379bb
---
 sound/soc/rockchip/rockchip_pdm.c | 44 +++++++++++++++++++++++++++++--
 1 file changed, 42 insertions(+), 2 deletions(-)

diff --git a/sound/soc/rockchip/rockchip_pdm.c b/sound/soc/rockchip/rockchip_pdm.c
index bb4f1e2504dd..ad5e8b706c2c 100644
--- a/sound/soc/rockchip/rockchip_pdm.c
+++ b/sound/soc/rockchip/rockchip_pdm.c
@@ -31,8 +31,10 @@
 #define PDM_FILTER_DELAY_MS_MIN		(20)
 #define PDM_FILTER_DELAY_MS_MAX		(1000)
 #define PDM_CLK_SHIFT_PPM_MAX		(1000000) /* 1 ppm */
-#define CLK_PPM_MIN		(-1000)
-#define CLK_PPM_MAX		(1000)
+#define CLK_PPM_MIN			(-1000)
+#define CLK_PPM_MAX			(1000)
+
+#define QUIRK_ALWAYS_ON			BIT(0)
 
 enum rk_pdm_version {
 	RK_PDM_RK3229,
@@ -56,6 +58,7 @@ struct rk_pdm_dev {
 	enum rk_pdm_version version;
 	unsigned int clk_root_rate;
 	unsigned int clk_root_initial_rate;
+	unsigned int quirks;
 	int clk_ppm;
 	bool clk_calibrate;
 };
@@ -97,6 +100,16 @@ static struct rk_pdm_ds_ratio ds_ratio[] = {
 	{ 4, 8000 },
 };
 
+static const struct pdm_of_quirks {
+	char *quirk;
+	int id;
+} of_quirks[] = {
+	{
+		.quirk = "rockchip,always-on",
+		.id = QUIRK_ALWAYS_ON,
+	},
+};
+
 static unsigned int get_pdm_clk(struct rk_pdm_dev *pdm, unsigned int sr,
 				unsigned int *clk_src, unsigned int *clk_out,
 				unsigned int signoff)
@@ -957,6 +970,29 @@ static int rockchip_pdm_path_parse(struct rk_pdm_dev *pdm, struct device_node *n
 	return 0;
 }
 
+static int rockchip_pdm_keep_clk_always_on(struct rk_pdm_dev *pdm)
+{
+	pm_runtime_forbid(pdm->dev);
+
+	dev_info(pdm->dev, "CLK-ALWAYS-ON: samplerate: %d\n", PDM_DEFAULT_RATE);
+
+	return 0;
+}
+
+static int rockchip_pdm_parse_quirks(struct rk_pdm_dev *pdm)
+{
+	int ret = 0, i = 0;
+
+	for (i = 0; i < ARRAY_SIZE(of_quirks); i++)
+		if (device_property_read_bool(pdm->dev, of_quirks[i].quirk))
+			pdm->quirks |= of_quirks[i].id;
+
+	if (pdm->quirks & QUIRK_ALWAYS_ON)
+		ret = rockchip_pdm_keep_clk_always_on(pdm);
+
+	return ret;
+}
+
 static int rockchip_pdm_probe(struct platform_device *pdev)
 {
 	struct device_node *node = pdev->dev.of_node;
@@ -1038,6 +1074,10 @@ static int rockchip_pdm_probe(struct platform_device *pdev)
 	if (ret != 0 && ret != -ENOENT)
 		goto err_clk;
 
+	ret = rockchip_pdm_parse_quirks(pdm);
+	if (ret)
+		goto err_clk;
+
 	/*
 	 * MUST: after pm_runtime_enable step, any register R/W
 	 * should be wrapped with pm_runtime_get_sync/put.