[PATCH v4 2/5] i3c: master: svc: Add support for Nuvoton npcm845 i3c

[Stanley Chu <stanley.chuys@gmail.com>]

From: Stanley Chu <yschu@nuvoton.com>

Nuvoton npcm845 SoC uses the same Silvico IP but an older version.
Add quirks to address the npcm845 specific issues.

Signed-off-by: Stanley Chu <yschu@nuvoton.com>
---
 drivers/i3c/master/svc-i3c-master.c | 56 +++++++++++++++++++++++++++++
 1 file changed, 56 insertions(+)

diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index d6057d8c7dec..8834f87a4767 100644
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -32,6 +32,7 @@
 #define   SVC_I3C_MCONFIG_ODBAUD(x) FIELD_PREP(GENMASK(23, 16), (x))
 #define   SVC_I3C_MCONFIG_ODHPP(x) FIELD_PREP(BIT(24), (x))
 #define   SVC_I3C_MCONFIG_SKEW(x) FIELD_PREP(GENMASK(27, 25), (x))
+#define   SVC_I3C_MCONFIG_SKEW_MASK GENMASK(27, 25)
 #define   SVC_I3C_MCONFIG_I2CBAUD(x) FIELD_PREP(GENMASK(31, 28), (x))
 
 #define SVC_I3C_MCTRL        0x084
@@ -133,6 +134,32 @@
 #define SVC_I3C_EVENT_IBI	GENMASK(7, 0)
 #define SVC_I3C_EVENT_HOTJOIN	BIT(31)
 
+/*
+ * SVC_I3C_QUIRK_FIFO_EMPTY:
+ * I3C HW stalls the write transfer if the transmit FIFO becomes empty,
+ * when new data is written to FIFO, I3C HW resumes the transfer but
+ * the first transmitted data bit may have the wrong value.
+ * Workaround:
+ * Fill the FIFO in advance to prevent FIFO from becoming empty.
+ */
+#define SVC_I3C_QUIRK_FIFO_EMPTY	BIT(0)
+/*
+ * SVC_I3C_QUIRK_FLASE_SLVSTART:
+ * I3C HW may generate an invalid SlvStart event when emitting a STOP.
+ * If it is a true SlvStart, the MSTATUS state is SLVREQ.
+ */
+#define SVC_I3C_QUIRK_FALSE_SLVSTART	BIT(1)
+/*
+ * SVC_I3C_QUIRK_DAA_CORRUPT:
+ * When MCONFIG.SKEW=0 and MCONFIG.ODHPP=0, the ENTDAA transaction gets
+ * corrupted and results in a no repeated-start condition at the end of
+ * address assignment.
+ * Workaround:
+ * Set MCONFIG.SKEW to 1 before initiating the DAA process. After the DAA
+ * process is completed, return MCONFIG.SKEW to its previous value.
+ */
+#define SVC_I3C_QUIRK_DAA_CORRUPT	BIT(2)
+
 struct svc_i3c_cmd {
 	u8 addr;
 	bool rnw;
@@ -158,6 +185,10 @@ struct svc_i3c_regs_save {
 	u32 mdynaddr;
 };
 
+struct svc_i3c_drvdata {
+	u32 quirks;
+};
+
 /**
  * struct svc_i3c_master - Silvaco I3C Master structure
  * @base: I3C master controller
@@ -183,6 +214,7 @@ struct svc_i3c_regs_save {
  * @ibi.tbq_slot: To be queued IBI slot
  * @ibi.lock: IBI lock
  * @lock: Transfer lock, protect between IBI work thread and callbacks from master
+ * @drvdata: Driver data
  * @enabled_events: Bit masks for enable events (IBI, HotJoin).
  * @mctrl_config: Configuration value in SVC_I3C_MCTRL for setting speed back.
  */
@@ -214,6 +246,7 @@ struct svc_i3c_master {
 		spinlock_t lock;
 	} ibi;
 	struct mutex lock;
+	const struct svc_i3c_drvdata *drvdata;
 	u32 enabled_events;
 	u32 mctrl_config;
 };
@@ -230,6 +263,27 @@ struct svc_i3c_i2c_dev_data {
 	struct i3c_generic_ibi_pool *ibi_pool;
 };
 
+const struct svc_i3c_drvdata npcm845_drvdata = {
+	.quirks = SVC_I3C_QUIRK_FIFO_EMPTY | SVC_I3C_QUIRK_FALSE_SLVSTART
+		| SVC_I3C_QUIRK_DAA_CORRUPT,
+};
+
+static bool svc_has_quirk(struct svc_i3c_master *master, u32 quirk)
+{
+	if (!master->drvdata)
+		return false;
+
+	if ((master->drvdata->quirks & quirk) == SVC_I3C_QUIRK_DAA_CORRUPT) {
+		if (master->mctrl_config &
+		    (SVC_I3C_MCONFIG_SKEW_MASK | SVC_I3C_MCONFIG_ODHPP(1)))
+			return false;
+		else
+			return true;
+	}
+
+	return (master->drvdata->quirks & quirk);
+}
+
 static inline bool is_events_enabled(struct svc_i3c_master *master, u32 mask)
 {
 	return !!(master->enabled_events & mask);
@@ -1868,6 +1922,7 @@ static int svc_i3c_master_probe(struct platform_device *pdev)
 	}
 
 	platform_set_drvdata(pdev, master);
+	master->drvdata = of_device_get_match_data(dev);
 
 	pm_runtime_set_autosuspend_delay(&pdev->dev, SVC_I3C_PM_TIMEOUT_MS);
 	pm_runtime_use_autosuspend(&pdev->dev);
@@ -1960,6 +2015,7 @@ static const struct dev_pm_ops svc_i3c_pm_ops = {
 
 static const struct of_device_id svc_i3c_master_of_match_tbl[] = {
 	{ .compatible = "silvaco,i3c-master-v1"},
+	{ .compatible = "nuvoton,npcm845-i3c", .data = &npcm845_drvdata },
 	{ /* sentinel */ },
 };
 MODULE_DEVICE_TABLE(of, svc_i3c_master_of_match_tbl);
-- 
2.34.1