i3c: Add support for ast2600 i3c controller

index d73d57362b3b..49b891449222 100644
@@ -241,6 +241,17 @@ struct dw_i3c_master {
 	char version[5];
 	char type[5];
 	u8 addrs[MAX_DEVS];
+
+	/* platform-specific data */
+	const struct dw_i3c_platform_ops *platform_ops;
+	union {
+	} pdata;
+
+};
+
+struct dw_i3c_platform_ops {
+	int (*probe)(struct dw_i3c_master *i3c, struct platform_device *pdev);
+	int (*init)(struct dw_i3c_master *i3c);
 };
 
 struct dw_i3c_i2c_dev_data {

@@ -612,6 +623,12 @@ static int dw_i3c_master_bus_init(struct i3c_master_controller *m)
 	u32 thld_ctrl;
 	int ret;
 
+	if (master->platform_ops && master->platform_ops->init) {
+		ret = master->platform_ops->init(master);
+		if (ret)
+			return ret;
+	}
+
 	switch (bus->mode) {
 	case I3C_BUS_MODE_MIXED_FAST:
 	case I3C_BUS_MODE_MIXED_LIMITED:

@@ -1128,8 +1145,15 @@ static const struct i3c_master_controller_ops dw_mipi_i3c_ops = {
 	.i2c_xfers = dw_i3c_master_i2c_xfers,
 };
 
+static const struct of_device_id dw_i3c_master_of_match[] = {
+	{ .compatible = "snps,dw-i3c-master-1.00a", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, dw_i3c_master_of_match);
+
 static int dw_i3c_probe(struct platform_device *pdev)
 {
+	const struct of_device_id *match;
 	struct dw_i3c_master *master;
 	int ret, irq;
 

@@ -1181,6 +1205,18 @@ static int dw_i3c_probe(struct platform_device *pdev)
 	master->maxdevs = ret >> 16;
 	master->free_pos = GENMASK(master->maxdevs - 1, 0);
 
+	/* match any platform-specific ops */
+	match = of_match_node(dw_i3c_master_of_match, pdev->dev.of_node);
+	if (match && match->data)
+		master->platform_ops = match->data;
+
+	/* platform-specific probe */
+	if (master->platform_ops && master->platform_ops->probe) {
+		ret = master->platform_ops->probe(master, pdev);
+		if (ret)
+			goto err_assert_rst;
+	}
+
 	ret = i3c_master_register(&master->base, &pdev->dev,
 				  &dw_mipi_i3c_ops, false);
 	if (ret)

@@ -1213,12 +1249,6 @@ static int dw_i3c_remove(struct platform_device *pdev)
 	return 0;
 }
 
-static const struct of_device_id dw_i3c_master_of_match[] = {
-	{ .compatible = "snps,dw-i3c-master-1.00a", },
-	{},
-};
-MODULE_DEVICE_TABLE(of, dw_i3c_master_of_match);
-
 static struct platform_driver dw_i3c_driver = {
 	.probe = dw_i3c_probe,
 	.remove = dw_i3c_remove,

index 49b891449222..9be3348cba0e 100644
@@ -16,8 +16,10 @@
 #include <linux/iopoll.h>
 #include <linux/list.h>
 #include <linux/module.h>
+#include <linux/mfd/syscon.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/regmap.h>
 #include <linux/reset.h>
 #include <linux/slab.h>
 

@@ -201,6 +203,28 @@
 
 #define XFER_TIMEOUT (msecs_to_jiffies(1000))
 
+/* AST2600-specific global register set */
+#define AST2600_I3CG_REG0(idx)	(((idx) * 4 * 4) + 0x10)
+#define AST2600_I3CG_REG1(idx)	(((idx) * 4 * 4) + 0x14)
+
+#define AST2600_I3CG_REG0_SDA_PULLUP_EN_MASK	GENMASK(29, 28)
+#define AST2600_I3CG_REG0_SDA_PULLUP_EN_2K	(0x0 << 28)
+#define AST2600_I3CG_REG0_SDA_PULLUP_EN_750	(0x2 << 28)
+
+#define AST2600_I3CG_REG1_I2C_MODE		BIT(0)
+#define AST2600_I3CG_REG1_TEST_MODE		BIT(1)
+#define AST2600_I3CG_REG1_ACT_MODE_MASK		GENMASK(3, 2)
+#define AST2600_I3CG_REG1_ACT_MODE(x)		(((x) << 2) & AST2600_I3CG_REG1_ACT_MODE_MASK)
+#define AST2600_I3CG_REG1_PENDING_INT_MASK	GENMASK(7, 4)
+#define AST2600_I3CG_REG1_PENDING_INT(x)	(((x) << 4) & AST2600_I3CG_REG1_PENDING_INT_MASK)
+#define AST2600_I3CG_REG1_SA_MASK		GENMASK(14, 8)
+#define AST2600_I3CG_REG1_SA(x)			(((x) << 8) & AST2600_I3CG_REG1_SA_MASK)
+#define AST2600_I3CG_REG1_SA_EN			BIT(15)
+#define AST2600_I3CG_REG1_INST_ID_MASK		GENMASK(19, 16)
+#define AST2600_I3CG_REG1_INST_ID(x)		(((x) << 16) & AST2600_I3CG_REG1_INST_ID_MASK)
+
+#define AST2600_DEFAULT_SDA_PULLUP_OHMS		2000
+
 struct dw_i3c_master_caps {
 	u8 cmdfifodepth;
 	u8 datafifodepth;

@@ -224,6 +248,12 @@ struct dw_i3c_xfer {
 	struct dw_i3c_cmd cmds[];
 };
 
+struct pdata_ast2600 {
+	struct regmap *global_regs;
+	unsigned int global_idx;
+	unsigned int sda_pullup;
+};
+
 struct dw_i3c_master {
 	struct i3c_master_controller base;
 	u16 maxdevs;

@@ -245,6 +275,7 @@ struct dw_i3c_master {
 	/* platform-specific data */
 	const struct dw_i3c_platform_ops *platform_ops;
 	union {
+		struct pdata_ast2600 ast2600;
 	} pdata;
 
 };

@@ -1145,6 +1176,97 @@ static const struct i3c_master_controller_ops dw_mipi_i3c_ops = {
 	.i2c_xfers = dw_i3c_master_i2c_xfers,
 };
 
+/* hardware-specific ops */
+
+static int ast2600_i3c_pullup_to_reg(unsigned int ohms, u32 *regp)
+{
+	u32 reg;
+
+	switch (ohms) {
+	case 2000:
+		reg = AST2600_I3CG_REG0_SDA_PULLUP_EN_2K;
+		break;
+	case 750:
+		reg = AST2600_I3CG_REG0_SDA_PULLUP_EN_750;
+		break;
+	case 545:
+		reg = AST2600_I3CG_REG0_SDA_PULLUP_EN_2K |
+			AST2600_I3CG_REG0_SDA_PULLUP_EN_750;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (regp)
+		*regp = reg;
+
+	return 0;
+}
+
+static int ast2600_i3c_probe(struct dw_i3c_master *master,
+			     struct platform_device *pdev)
+{
+	struct pdata_ast2600 *pdata = &master->pdata.ast2600;
+	struct device_node *np = pdev->dev.of_node;
+	struct of_phandle_args gspec;
+	int rc;
+
+	rc = of_parse_phandle_with_fixed_args(np, "aspeed,global-regs", 1, 0,
+					      &gspec);
+	if (rc)
+		return -ENODEV;
+
+	pdata->global_regs = syscon_node_to_regmap(gspec.np);
+	of_node_put(gspec.np);
+
+	if (IS_ERR(pdata->global_regs))
+		return PTR_ERR(pdata->global_regs);
+
+	pdata->global_idx = gspec.args[0];
+
+	rc = of_property_read_u32(np, "sda-pullup-ohms", &pdata->sda_pullup);
+	if (rc)
+		pdata->sda_pullup = AST2600_DEFAULT_SDA_PULLUP_OHMS;
+
+	rc = ast2600_i3c_pullup_to_reg(pdata->sda_pullup, NULL);
+	if (rc)
+		dev_err(&master->base.dev, "invalid sda-pullup value %d\n",
+			pdata->sda_pullup);
+
+	return rc;
+}
+
+static int ast2600_i3c_init(struct dw_i3c_master *master)
+{
+	struct pdata_ast2600 *pdata = &master->pdata.ast2600;
+	u32 reg = 0;
+	int rc;
+
+	/* reg0: set SDA pullup values */
+	rc = ast2600_i3c_pullup_to_reg(pdata->sda_pullup, &reg);
+	if (rc)
+		return rc;
+
+	rc = regmap_write(pdata->global_regs,
+			  AST2600_I3CG_REG0(pdata->global_idx), reg);
+	if (rc)
+		return rc;
+
+	/* reg1: set up the instance id, but leave everything else disabled,
+	 * as it's all for client mode
+	 */
+	reg = AST2600_I3CG_REG1_INST_ID(pdata->global_idx);
+	rc = regmap_write(pdata->global_regs,
+			  AST2600_I3CG_REG1(pdata->global_idx), reg);
+
+	return rc;
+}
+
+static const struct dw_i3c_platform_ops ast2600_platform_ops = {
+	.probe = ast2600_i3c_probe,
+	.init = ast2600_i3c_init,
+};
+
 static const struct of_device_id dw_i3c_master_of_match[] = {
 	{ .compatible = "snps,dw-i3c-master-1.00a", },
 	{},

index 9be3348cba0e..5ac226e0c558 100644
@@ -1269,6 +1269,7 @@ static const struct dw_i3c_platform_ops ast2600_platform_ops = {
 
 static const struct of_device_id dw_i3c_master_of_match[] = {
 	{ .compatible = "snps,dw-i3c-master-1.00a", },
+	{ .compatible = "aspeed,ast2600-i3c", .data = &ast2600_platform_ops },
 	{},
 };
 MODULE_DEVICE_TABLE(of, dw_i3c_master_of_match);