Merge tag 'i3c/for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux

Pull i3c updates from Alexandre Belloni:
 "Subsystem:
   - OF alias bus numbering
   - convert to platform remove callback returning void

  New driver:
   - AST2600 controller, based on Synopsys DesignWare IP

  Driver update:
   - dw: add infrastructure to support different platform integrations"

* tag 'i3c/for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux:
  i3c: ast2600: set variable ast2600_i3c_ops storage-class-specifier to static
  i3c: ast2600: fix register setting for 545 ohm pullups
  i3c: ast2600: enable IBI support
  i3c: dw: Add a platform facility for IBI PEC workarounds
  i3c: dw: Add support for in-band interrupts
  i3c: dw: Turn DAT array entry into a struct
  i3c: dw: Create a generic fifo read function
  i3c: Allow OF-alias-based persistent bus numbering
  i3c: ast2600: Add AST2600 platform-specific driver
  dt-bindings: i3c: Add AST2600 i3c controller
  i3c: dw: Add infrastructure for platform-specific implementations
  i3c: dw: use bus mode rather than device reg for conditional tCAS setting
  i3c: dw: Return the length from a read priv_xfer
  i3c: svc: Convert to platform remove callback returning void
  i3c: mipi-i3c-hci: Convert to platform remove callback returning void
  i3c: cdns: Convert to platform remove callback returning void
  i3c: dw: Convert to platform remove callback returning void
  i3c: Make i3c_master_unregister() return void
  i3c: dw: drop of_match_ptr for ID table
  i3c: Correct reference to the I²C device data type

Documentation/devicetree/bindings/i3c/aspeed,ast2600-i3c.yaml

+# SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/i3c/aspeed,ast2600-i3c.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ASPEED AST2600 i3c controller
+
+maintainers:
+  - Jeremy Kerr <jk@codeconstruct.com.au>
+
+allOf:
+  - $ref: i3c.yaml#
+
+properties:
+  compatible:
+    const: aspeed,ast2600-i3c
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  sda-pullup-ohms:
+    enum: [545, 750, 2000]
+    default: 2000
+    description: |
+      Value to configure SDA pullup resistor, in Ohms.
+
+  aspeed,global-regs:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    items:
+      - items:
+          - description: phandle to i3c global register syscon node
+          - description: index of this i3c controller in the global register set
+    description: |
+      A (phandle, controller index) reference to the i3c global register set
+      used for this device.
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - interrupts
+  - aspeed,global-regs
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    i3c-master@2000 {
+        compatible = "aspeed,ast2600-i3c";
+        reg = <0x2000 0x1000>;
+        #address-cells = <3>;
+        #size-cells = <0>;
+        clocks = <&syscon 0>;
+        resets = <&syscon 0>;
+        aspeed,global-regs = <&i3c_global 0>;
+        pinctrl-names = "default";
+        pinctrl-0 = <&pinctrl_i3c1_default>;
+        interrupts = <GIC_SPI 102 IRQ_TYPE_LEVEL_HIGH>;
+    };
+...

MAINTAINERS

@@ -9778,6 +9778,12 @@ S:	Orphan
 F:	Documentation/devicetree/bindings/i3c/snps,dw-i3c-master.yaml
 F:	drivers/i3c/master/dw*
 
+I3C DRIVER FOR ASPEED AST2600
+M:	Jeremy Kerr <jk@codeconstruct.com.au>
+S:	Maintained
+F:	Documentation/devicetree/bindings/i3c/aspeed,ast2600-i3c.yaml
+F:	drivers/i3c/master/ast2600-i3c-master.c
+
 I3C SUBSYSTEM
 M:	Alexandre Belloni <alexandre.belloni@bootlin.com>
 L:	linux-i3c@lists.infradead.org (moderated for non-subscribers)

drivers/i3c/master.c

@@ -21,6 +21,7 @@
 
 static DEFINE_IDR(i3c_bus_idr);
 static DEFINE_MUTEX(i3c_core_lock);
+static int __i3c_first_dynamic_bus_num;
 
 /**
  * i3c_bus_maintenance_lock - Lock the bus for a maintenance operation
@@ -419,9 +420,9 @@ static void i3c_bus_cleanup(struct i3c_bus *i3cbus)
 	mutex_unlock(&i3c_core_lock);
 }
 
-static int i3c_bus_init(struct i3c_bus *i3cbus)
+static int i3c_bus_init(struct i3c_bus *i3cbus, struct device_node *np)
 {
-	int ret;
+	int ret, start, end, id = -1;
 
 	init_rwsem(&i3cbus->lock);
 	INIT_LIST_HEAD(&i3cbus->devs.i2c);
@@ -429,8 +430,19 @@ static int i3c_bus_init(struct i3c_bus *i3cbus)
 	i3c_bus_init_addrslots(i3cbus);
 	i3cbus->mode = I3C_BUS_MODE_PURE;
 
+	if (np)
+		id = of_alias_get_id(np, "i3c");
+
 	mutex_lock(&i3c_core_lock);
-	ret = idr_alloc(&i3c_bus_idr, i3cbus, 0, 0, GFP_KERNEL);
+	if (id >= 0) {
+		start = id;
+		end = start + 1;
+	} else {
+		start = __i3c_first_dynamic_bus_num;
+		end = 0;
+	}
+
+	ret = idr_alloc(&i3c_bus_idr, i3cbus, start, end, GFP_KERNEL);
 	mutex_unlock(&i3c_core_lock);
 
 	if (ret < 0)
@@ -2606,7 +2618,7 @@ int i3c_master_register(struct i3c_master_controller *master,
 	INIT_LIST_HEAD(&master->boardinfo.i2c);
 	INIT_LIST_HEAD(&master->boardinfo.i3c);
 
-	ret = i3c_bus_init(i3cbus);
+	ret = i3c_bus_init(i3cbus, master->dev.of_node);
 	if (ret)
 		return ret;
 
@@ -2695,17 +2707,13 @@ EXPORT_SYMBOL_GPL(i3c_master_register);
  * @master: master used to send frames on the bus
  *
  * Basically undo everything done in i3c_master_register().
- *
- * Return: 0 in case of success, a negative error code otherwise.
  */
-int i3c_master_unregister(struct i3c_master_controller *master)
+void i3c_master_unregister(struct i3c_master_controller *master)
 {
 	i3c_master_i2c_adapter_cleanup(master);
 	i3c_master_unregister_i3c_devs(master);
 	i3c_master_bus_cleanup(master);
 	device_unregister(&master->dev);
-
-	return 0;
 }
 EXPORT_SYMBOL_GPL(i3c_master_unregister);
 
@@ -2834,8 +2842,16 @@ void i3c_dev_free_ibi_locked(struct i3c_dev_desc *dev)
 
 static int __init i3c_init(void)
 {
-	int res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier);
+	int res;
+
+	res = of_alias_get_highest_id("i3c");
+	if (res >= 0) {
+		mutex_lock(&i3c_core_lock);
+		__i3c_first_dynamic_bus_num = res + 1;
+		mutex_unlock(&i3c_core_lock);
+	}
 
+	res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier);
 	if (res)
 		return res;
 

drivers/i3c/master/Kconfig

@@ -22,6 +22,20 @@ config DW_I3C_MASTER
 	  This driver can also be built as a module.  If so, the module
 	  will be called dw-i3c-master.
 
+config AST2600_I3C_MASTER
+	tristate "ASPEED AST2600 I3C master driver"
+	depends on DW_I3C_MASTER
+	depends on ARCH_ASPEED || COMPILE_TEST
+	select MFD_SYSCON
+	help
+	  Support for ASPEED AST2600 I3C Controller.
+
+	  This hardware is an instance of the DW I3C controller; this
+	  driver adds platform- specific support for AST2600 hardware.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called ast2600-i3c-master.
+
 config SVC_I3C_MASTER
 	tristate "Silvaco I3C Dual-Role Master driver"
 	depends on I3C

drivers/i3c/master/Makefile

 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_CDNS_I3C_MASTER)		+= i3c-master-cdns.o
 obj-$(CONFIG_DW_I3C_MASTER)		+= dw-i3c-master.o
+obj-$(CONFIG_AST2600_I3C_MASTER)	+= ast2600-i3c-master.o
 obj-$(CONFIG_SVC_I3C_MASTER)		+= svc-i3c-master.o
 obj-$(CONFIG_MIPI_I3C_HCI)		+= mipi-i3c-hci/

drivers/i3c/master/ast2600-i3c-master.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2023 Code Construct
+ *
+ * Author: Jeremy Kerr <jk@codeconstruct.com.au>
+ */
+
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include "dw-i3c-master.h"
+
+/* 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_REG0_SDA_PULLUP_EN_545	(0x3 << 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
+
+#define DEV_ADDR_TABLE_IBI_PEC			BIT(11)
+
+struct ast2600_i3c {
+	struct dw_i3c_master dw;
+	struct regmap *global_regs;
+	unsigned int global_idx;
+	unsigned int sda_pullup;
+};
+
+static struct ast2600_i3c *to_ast2600_i3c(struct dw_i3c_master *dw)
+{
+	return container_of(dw, struct ast2600_i3c, dw);
+}
+
+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_545;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (regp)
+		*regp = reg;
+
+	return 0;
+}
+
+static int ast2600_i3c_init(struct dw_i3c_master *dw)
+{
+	struct ast2600_i3c *i3c = to_ast2600_i3c(dw);
+	u32 reg = 0;
+	int rc;
+
+	/* reg0: set SDA pullup values */
+	rc = ast2600_i3c_pullup_to_reg(i3c->sda_pullup, &reg);
+	if (rc)
+		return rc;
+
+	rc = regmap_write(i3c->global_regs,
+			  AST2600_I3CG_REG0(i3c->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(i3c->global_idx);
+	rc = regmap_write(i3c->global_regs,
+			  AST2600_I3CG_REG1(i3c->global_idx), reg);
+
+	return rc;
+}
+
+static void ast2600_i3c_set_dat_ibi(struct dw_i3c_master *i3c,
+				    struct i3c_dev_desc *dev,
+				    bool enable, u32 *dat)
+{
+	/*
+	 * The ast2600 i3c controller will lock up on receiving 4n+1-byte IBIs
+	 * if the PEC is disabled. We have no way to restrict the length of
+	 * IBIs sent to the controller, so we need to unconditionally enable
+	 * PEC checking, which means we drop a byte of payload data
+	 */
+	if (enable && dev->info.bcr & I3C_BCR_IBI_PAYLOAD) {
+		dev_warn_once(&i3c->base.dev,
+		      "Enabling PEC workaround. IBI payloads will be truncated\n");
+		*dat |= DEV_ADDR_TABLE_IBI_PEC;
+	}
+}
+
+static const struct dw_i3c_platform_ops ast2600_i3c_ops = {
+	.init = ast2600_i3c_init,
+	.set_dat_ibi = ast2600_i3c_set_dat_ibi,
+};
+
+static int ast2600_i3c_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct of_phandle_args gspec;
+	struct ast2600_i3c *i3c;
+	int rc;
+
+	i3c = devm_kzalloc(&pdev->dev, sizeof(*i3c), GFP_KERNEL);
+	if (!i3c)
+		return -ENOMEM;
+
+	rc = of_parse_phandle_with_fixed_args(np, "aspeed,global-regs", 1, 0,
+					      &gspec);
+	if (rc)
+		return -ENODEV;
+
+	i3c->global_regs = syscon_node_to_regmap(gspec.np);
+	of_node_put(gspec.np);
+
+	if (IS_ERR(i3c->global_regs))
+		return PTR_ERR(i3c->global_regs);
+
+	i3c->global_idx = gspec.args[0];
+
+	rc = of_property_read_u32(np, "sda-pullup-ohms", &i3c->sda_pullup);
+	if (rc)
+		i3c->sda_pullup = AST2600_DEFAULT_SDA_PULLUP_OHMS;
+
+	rc = ast2600_i3c_pullup_to_reg(i3c->sda_pullup, NULL);
+	if (rc)
+		dev_err(&pdev->dev, "invalid sda-pullup value %d\n",
+			i3c->sda_pullup);
+
+	i3c->dw.platform_ops = &ast2600_i3c_ops;
+	i3c->dw.ibi_capable = true;
+	return dw_i3c_common_probe(&i3c->dw, pdev);
+}
+
+static void ast2600_i3c_remove(struct platform_device *pdev)
+{
+	struct dw_i3c_master *dw_i3c = platform_get_drvdata(pdev);
+
+	dw_i3c_common_remove(dw_i3c);
+}
+
+static const struct of_device_id ast2600_i3c_master_of_match[] = {
+	{ .compatible = "aspeed,ast2600-i3c", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ast2600_i3c_master_of_match);
+
+static struct platform_driver ast2600_i3c_driver = {
+	.probe = ast2600_i3c_probe,
+	.remove_new = ast2600_i3c_remove,
+	.driver = {
+		.name = "ast2600-i3c-master",
+		.of_match_table = ast2600_i3c_master_of_match,
+	},
+};
+module_platform_driver(ast2600_i3c_driver);
+
+MODULE_AUTHOR("Jeremy Kerr <jk@codeconstruct.com.au>");
+MODULE_DESCRIPTION("ASPEED AST2600 I3C driver");
+MODULE_LICENSE("GPL");

drivers/i3c/master/dw-i3c-master.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2023 Code Construct
+ *
+ * Author: Jeremy Kerr <jk@codeconstruct.com.au>
+ */
+
+#include <linux/clk.h>
+#include <linux/i3c/master.h>
+#include <linux/reset.h>
+#include <linux/types.h>
+
+#define DW_I3C_MAX_DEVS 32
+
+struct dw_i3c_master_caps {
+	u8 cmdfifodepth;
+	u8 datafifodepth;
+};
+
+struct dw_i3c_dat_entry {
+	u8 addr;
+	struct i3c_dev_desc *ibi_dev;
+};
+
+struct dw_i3c_master {
+	struct i3c_master_controller base;
+	u16 maxdevs;
+	u16 datstartaddr;
+	u32 free_pos;
+	struct {
+		struct list_head list;
+		struct dw_i3c_xfer *cur;
+		spinlock_t lock;
+	} xferqueue;
+	struct dw_i3c_master_caps caps;
+	void __iomem *regs;
+	struct reset_control *core_rst;
+	struct clk *core_clk;
+	char version[5];
+	char type[5];
+	bool ibi_capable;
+
+	/*
+	 * Per-device hardware data, used to manage the device address table
+	 * (DAT)
+	 *
+	 * Locking: the devs array may be referenced in IRQ context while
+	 * processing an IBI. However, IBIs (for a specific device, which
+	 * implies a specific DAT entry) can only happen while interrupts are
+	 * requested for that device, which is serialised against other
+	 * insertions/removals from the array by the global i3c infrastructure.
+	 * So, devs_lock protects against concurrent updates to devs->ibi_dev
+	 * between request_ibi/free_ibi and the IBI irq event.
+	 */
+	struct dw_i3c_dat_entry devs[DW_I3C_MAX_DEVS];
+	spinlock_t devs_lock;
+
+	/* platform-specific data */
+	const struct dw_i3c_platform_ops *platform_ops;
+};
+
+struct dw_i3c_platform_ops {
+	/*
+	 * Called on early bus init: the i3c has been set up, but before any
+	 * transactions have taken place. Platform implementations may use to
+	 * perform actual device enabling with the i3c core ready.
+	 */
+	int (*init)(struct dw_i3c_master *i3c);
+
+	/*
+	 * Initialise a DAT entry to enable/disable IBIs. Allows the platform
+	 * to perform any device workarounds on the DAT entry before
+	 * inserting into the hardware table.
+	 *
+	 * Called with the DAT lock held; must not sleep.
+	 */
+	void (*set_dat_ibi)(struct dw_i3c_master *i3c,
+			    struct i3c_dev_desc *dev, bool enable, u32 *reg);
+};
+
+extern int dw_i3c_common_probe(struct dw_i3c_master *master,
+			       struct platform_device *pdev);
+extern void dw_i3c_common_remove(struct dw_i3c_master *master);
+

drivers/i3c/master/i3c-master-cdns.c

@@ -1662,24 +1662,19 @@ static int cdns_i3c_master_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static int cdns_i3c_master_remove(struct platform_device *pdev)
+static void cdns_i3c_master_remove(struct platform_device *pdev)
 {
 	struct cdns_i3c_master *master = platform_get_drvdata(pdev);
-	int ret;
 
-	ret = i3c_master_unregister(&master->base);
-	if (ret)
-		return ret;
+	i3c_master_unregister(&master->base);
 
 	clk_disable_unprepare(master->sysclk);
 	clk_disable_unprepare(master->pclk);
-
-	return 0;
 }
 
 static struct platform_driver cdns_i3c_master = {
 	.probe = cdns_i3c_master_probe,
-	.remove = cdns_i3c_master_remove,
+	.remove_new = cdns_i3c_master_remove,
 	.driver = {
 		.name = "cdns-i3c-master",
 		.of_match_table = cdns_i3c_master_of_ids,

drivers/i3c/master/mipi-i3c-hci/core.c

@@ -765,11 +765,11 @@ static int i3c_hci_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static int i3c_hci_remove(struct platform_device *pdev)
+static void i3c_hci_remove(struct platform_device *pdev)
 {
 	struct i3c_hci *hci = platform_get_drvdata(pdev);
 
-	return i3c_master_unregister(&hci->master);
+	i3c_master_unregister(&hci->master);
 }
 
 static const __maybe_unused struct of_device_id i3c_hci_of_match[] = {
@@ -780,7 +780,7 @@ MODULE_DEVICE_TABLE(of, i3c_hci_of_match);
 
 static struct platform_driver i3c_hci_driver = {
 	.probe = i3c_hci_probe,
-	.remove = i3c_hci_remove,
+	.remove_new = i3c_hci_remove,
 	.driver = {
 		.name = "mipi-i3c-hci",
 		.of_match_table = of_match_ptr(i3c_hci_of_match),

drivers/i3c/master/svc-i3c-master.c

@@ -1569,19 +1569,14 @@ static int svc_i3c_master_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static int svc_i3c_master_remove(struct platform_device *pdev)
+static void svc_i3c_master_remove(struct platform_device *pdev)
 {
 	struct svc_i3c_master *master = platform_get_drvdata(pdev);
-	int ret;
 
-	ret = i3c_master_unregister(&master->base);
-	if (ret)
-		return ret;
+	i3c_master_unregister(&master->base);
 
 	pm_runtime_dont_use_autosuspend(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
-
-	return 0;
 }
 
 static int __maybe_unused svc_i3c_runtime_suspend(struct device *dev)
@@ -1619,7 +1614,7 @@ MODULE_DEVICE_TABLE(of, svc_i3c_master_of_match_tbl);
 
 static struct platform_driver svc_i3c_master = {
 	.probe = svc_i3c_master_probe,
-	.remove = svc_i3c_master_remove,
+	.remove_new = svc_i3c_master_remove,
 	.driver = {
 		.name = "silvaco-i3c-master",
 		.of_match_table = svc_i3c_master_of_match_tbl,

include/linux/i3c/master.h

@@ -22,9 +22,10 @@
 #define I3C_BROADCAST_ADDR		0x7e
 #define I3C_MAX_ADDR			GENMASK(6, 0)
 
+struct i2c_client;
+
 struct i3c_master_controller;
 struct i3c_bus;
-struct i2c_device;
 struct i3c_device;
 
 /**
@@ -541,7 +542,7 @@ int i3c_master_register(struct i3c_master_controller *master,
 			struct device *parent,
 			const struct i3c_master_controller_ops *ops,
 			bool secondary);
-int i3c_master_unregister(struct i3c_master_controller *master);
+void i3c_master_unregister(struct i3c_master_controller *master);
 
 /**
  * i3c_dev_get_master_data() - get master private data attached to an I3C