[PATCH v2 00/11] Add Apple M1 support to PASemi i2c driver

@@ -0,0 +1,61 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: "http://devicetree.org/schemas/i2c/apple,i2c.yaml#"
+$schema: "http://devicetree.org/meta-schemas/core.yaml#"
+
+title: Apple/PASemi I2C controller
+
+maintainers:
+  - Sven Peter <sven@svenpeter.dev>
+
+description: |
+  Apple SoCs such as the M1 come with a I2C controller based on the one found
+  in machines with P. A. Semi's PWRficient processors.
+  The bus is used to communicate with e.g. USB PD chips or the speaker
+  amp.
+
+allOf:
+  - $ref: /schemas/i2c/i2c-controller.yaml#
+
+properties:
+  compatible:
+    enum:
+      - apple,t8103-i2c
+      - apple,i2c
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    items:
+      - description: I2C bus reference clock
+
+  interrupts:
+    maxItems: 1
+
+  clock-frequency:
+    description: |
+      Desired I2C bus clock frequency in Hz. If not specified, 100 kHz will be
+      used. This frequency is generated by dividing the reference clock.
+      Allowed values are between ref_clk/(16*4) and ref_clk/(16*255).
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - interrupts
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    i2c@35010000 {
+      compatible = "apple,t8103-i2c";
+      reg = <0x35010000 0x4000>;
+      interrupt-parent = <&aic>;
+      interrupts = <0 627 4>;
+      clocks = <&ref_clk>;
+      #address-cells = <1>;
+      #size-cells = <0>;
+    };

@@ -1735,6 +1735,7 @@ B:	https://github.com/AsahiLinux/linux/issues
 C:	irc://irc.oftc.net/asahi-dev
 T:	git https://github.com/AsahiLinux/linux.git
 F:	Documentation/devicetree/bindings/arm/apple.yaml
+F:	Documentation/devicetree/bindings/i2c/apple,i2c.yaml
 F:	Documentation/devicetree/bindings/interrupt-controller/apple,aic.yaml
 F:	Documentation/devicetree/bindings/pci/apple,pcie.yaml
 F:	Documentation/devicetree/bindings/pinctrl/apple,pinctrl.yaml

@@ -20,6 +20,7 @@ static struct pci_driver pasemi_smb_driver;
 struct pasemi_smbus {
 	struct pci_dev		*dev;
 	struct i2c_adapter	 adapter;
+	void __iomem		*ioaddr;
 	unsigned long		 base;
 	int			 size;
 };

@@ -53,13 +54,13 @@ static inline void reg_write(struct pasemi_smbus *smbus, int reg, int val)
 {
 	dev_dbg(&smbus->dev->dev, "smbus write reg %lx val %08x\n",
 		smbus->base + reg, val);
-	outl(val, smbus->base + reg);
+	iowrite32(val, smbus->ioaddr + reg);
 }
 
 static inline int reg_read(struct pasemi_smbus *smbus, int reg)
 {
 	int ret;
-	ret = inl(smbus->base + reg);
+	ret = ioread32(smbus->ioaddr + reg);
 	dev_dbg(&smbus->dev->dev, "smbus read reg %lx val %08x\n",
 		smbus->base + reg, ret);
 	return ret;

@@ -351,6 +352,12 @@ static int pasemi_smb_probe(struct pci_dev *dev,
 		goto out_kfree;
 	}
 
+	smbus->ioaddr = pci_iomap(dev, 0, 0);
+	if (!smbus->ioaddr) {
+		error = -EBUSY;
+		goto out_release_region;
+	}
+
 	smbus->adapter.owner = THIS_MODULE;
 	snprintf(smbus->adapter.name, sizeof(smbus->adapter.name),
 		 "PA Semi SMBus adapter at 0x%lx", smbus->base);

@@ -366,12 +373,14 @@ static int pasemi_smb_probe(struct pci_dev *dev,
 
 	error = i2c_add_adapter(&smbus->adapter);
 	if (error)
-		goto out_release_region;
+		goto out_ioport_unmap;
 
 	pci_set_drvdata(dev, smbus);
 
 	return 0;
 
+ out_ioport_unmap:
+	pci_iounmap(dev, smbus->ioaddr);
  out_release_region:
 	release_region(smbus->base, smbus->size);
  out_kfree:

@@ -384,6 +393,7 @@ static void pasemi_smb_remove(struct pci_dev *dev)
 	struct pasemi_smbus *smbus = pci_get_drvdata(dev);
 
 	i2c_del_adapter(&smbus->adapter);
+	pci_iounmap(dev, smbus->ioaddr);
 	release_region(smbus->base, smbus->size);
 	kfree(smbus);
 }

@@ -360,7 +360,7 @@ static int pasemi_smb_probe(struct pci_dev *dev,
 
 	smbus->adapter.owner = THIS_MODULE;
 	snprintf(smbus->adapter.name, sizeof(smbus->adapter.name),
-		 "PA Semi SMBus adapter at 0x%lx", smbus->base);
+		 "PA Semi SMBus adapter (%s)", dev_name(smbus->dev));
 	smbus->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
 	smbus->adapter.algo = &smbus_algorithm;
 	smbus->adapter.algo_data = smbus;

@@ -18,7 +18,7 @@
 static struct pci_driver pasemi_smb_driver;
 
 struct pasemi_smbus {
-	struct pci_dev		*dev;
+	struct device           *dev;
 	struct i2c_adapter	 adapter;
 	void __iomem		*ioaddr;
 	unsigned long		 base;

@@ -52,7 +52,7 @@ struct pasemi_smbus {
 
 static inline void reg_write(struct pasemi_smbus *smbus, int reg, int val)
 {
-	dev_dbg(&smbus->dev->dev, "smbus write reg %lx val %08x\n",
+	dev_dbg(smbus->dev, "smbus write reg %lx val %08x\n",
 		smbus->base + reg, val);
 	iowrite32(val, smbus->ioaddr + reg);
 }

@@ -61,7 +61,7 @@ static inline int reg_read(struct pasemi_smbus *smbus, int reg)
 {
 	int ret;
 	ret = ioread32(smbus->ioaddr + reg);
-	dev_dbg(&smbus->dev->dev, "smbus read reg %lx val %08x\n",
+	dev_dbg(smbus->dev, "smbus read reg %lx val %08x\n",
 		smbus->base + reg, ret);
 	return ret;
 }

@@ -94,7 +94,7 @@ static int pasemi_smb_waitready(struct pasemi_smbus *smbus)
 		return -ENXIO;
 
 	if (timeout < 0) {
-		dev_warn(&smbus->dev->dev, "Timeout, status 0x%08x\n", status);
+		dev_warn(smbus->dev, "Timeout, status 0x%08x\n", status);
 		reg_write(smbus, REG_SMSTA, status);
 		return -ETIME;
 	}

@@ -342,7 +342,7 @@ static int pasemi_smb_probe(struct pci_dev *dev,
 	if (!smbus)
 		return -ENOMEM;
 
-	smbus->dev = dev;
+	smbus->dev = &dev->dev;
 	smbus->base = pci_resource_start(dev, 0);
 	smbus->size = pci_resource_len(dev, 0);
 

@@ -366,7 +366,7 @@ static int pasemi_smb_probe(struct pci_dev *dev,
 	smbus->adapter.algo_data = smbus;
 
 	/* set up the sysfs linkage to our parent device */
-	smbus->adapter.dev.parent = &dev->dev;
+	smbus->adapter.dev.parent = smbus->dev;
 
 	reg_write(smbus, REG_CTL, (CTL_MTR | CTL_MRR |
 		  (CLK_100K_DIV & CTL_CLK_M)));

@@ -329,6 +329,30 @@ static const struct i2c_algorithm smbus_algorithm = {
 	.functionality	= pasemi_smb_func,
 };
 
+static int pasemi_i2c_common_probe(struct pasemi_smbus *smbus)
+{
+	int error;
+
+	smbus->adapter.owner = THIS_MODULE;
+	snprintf(smbus->adapter.name, sizeof(smbus->adapter.name),
+		 "PA Semi SMBus adapter (%s)", dev_name(smbus->dev));
+	smbus->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
+	smbus->adapter.algo = &smbus_algorithm;
+	smbus->adapter.algo_data = smbus;
+
+	/* set up the sysfs linkage to our parent device */
+	smbus->adapter.dev.parent = smbus->dev;
+
+	reg_write(smbus, REG_CTL, (CTL_MTR | CTL_MRR |
+		  (CLK_100K_DIV & CTL_CLK_M)));
+
+	error = i2c_add_adapter(&smbus->adapter);
+	if (error)
+		return error;
+
+	return 0;
+}
+
 static int pasemi_smb_probe(struct pci_dev *dev,
 				      const struct pci_device_id *id)
 {

@@ -358,20 +382,7 @@ static int pasemi_smb_probe(struct pci_dev *dev,
 		goto out_release_region;
 	}
 
-	smbus->adapter.owner = THIS_MODULE;
-	snprintf(smbus->adapter.name, sizeof(smbus->adapter.name),
-		 "PA Semi SMBus adapter (%s)", dev_name(smbus->dev));
-	smbus->adapter.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
-	smbus->adapter.algo = &smbus_algorithm;
-	smbus->adapter.algo_data = smbus;
-
-	/* set up the sysfs linkage to our parent device */
-	smbus->adapter.dev.parent = smbus->dev;
-
-	reg_write(smbus, REG_CTL, (CTL_MTR | CTL_MRR |
-		  (CLK_100K_DIV & CTL_CLK_M)));
-
-	error = i2c_add_adapter(&smbus->adapter);
+	int error = pasemi_i2c_common_probe(smbus);
 	if (error)
 		goto out_ioport_unmap;
 

@@ -84,6 +84,7 @@ obj-$(CONFIG_I2C_NPCM7XX)	+= i2c-npcm7xx.o
 obj-$(CONFIG_I2C_OCORES)	+= i2c-ocores.o
 obj-$(CONFIG_I2C_OMAP)		+= i2c-omap.o
 obj-$(CONFIG_I2C_OWL)		+= i2c-owl.o
+i2c-pasemi-objs := i2c-pasemi-core.o i2c-pasemi-pci.o
 obj-$(CONFIG_I2C_PASEMI)	+= i2c-pasemi.o
 obj-$(CONFIG_I2C_PCA_PLATFORM)	+= i2c-pca-platform.o
 obj-$(CONFIG_I2C_PNX)		+= i2c-pnx.o

@@ -15,15 +15,7 @@
 #include <linux/slab.h>
 #include <linux/io.h>
 
-static struct pci_driver pasemi_smb_driver;
-
-struct pasemi_smbus {
-	struct device           *dev;
-	struct i2c_adapter	 adapter;
-	void __iomem		*ioaddr;
-	unsigned long		 base;
-	int			 size;
-};
+#include "i2c-pasemi-core.h"
 
 /* Register offsets */
 #define REG_MTXFIFO	0x00

@@ -329,7 +321,7 @@ static const struct i2c_algorithm smbus_algorithm = {
 	.functionality	= pasemi_smb_func,
 };
 
-static int pasemi_i2c_common_probe(struct pasemi_smbus *smbus)
+int pasemi_i2c_common_probe(struct pasemi_smbus *smbus)
 {
 	int error;
 

@@ -352,79 +344,3 @@ static int pasemi_i2c_common_probe(struct pasemi_smbus *smbus)
 
 	return 0;
 }
-
-static int pasemi_smb_probe(struct pci_dev *dev,
-				      const struct pci_device_id *id)
-{
-	struct pasemi_smbus *smbus;
-	int error;
-
-	if (!(pci_resource_flags(dev, 0) & IORESOURCE_IO))
-		return -ENODEV;
-
-	smbus = kzalloc(sizeof(struct pasemi_smbus), GFP_KERNEL);
-	if (!smbus)
-		return -ENOMEM;
-
-	smbus->dev = &dev->dev;
-	smbus->base = pci_resource_start(dev, 0);
-	smbus->size = pci_resource_len(dev, 0);
-
-	if (!request_region(smbus->base, smbus->size,
-			    pasemi_smb_driver.name)) {
-		error = -EBUSY;
-		goto out_kfree;
-	}
-
-	smbus->ioaddr = pci_iomap(dev, 0, 0);
-	if (!smbus->ioaddr) {
-		error = -EBUSY;
-		goto out_release_region;
-	}
-
-	int error = pasemi_i2c_common_probe(smbus);
-	if (error)
-		goto out_ioport_unmap;
-
-	pci_set_drvdata(dev, smbus);
-
-	return 0;
-
- out_ioport_unmap:
-	pci_iounmap(dev, smbus->ioaddr);
- out_release_region:
-	release_region(smbus->base, smbus->size);
- out_kfree:
-	kfree(smbus);
-	return error;
-}
-
-static void pasemi_smb_remove(struct pci_dev *dev)
-{
-	struct pasemi_smbus *smbus = pci_get_drvdata(dev);
-
-	i2c_del_adapter(&smbus->adapter);
-	pci_iounmap(dev, smbus->ioaddr);
-	release_region(smbus->base, smbus->size);
-	kfree(smbus);
-}
-
-static const struct pci_device_id pasemi_smb_ids[] = {
-	{ PCI_DEVICE(0x1959, 0xa003) },
-	{ 0, }
-};
-
-MODULE_DEVICE_TABLE(pci, pasemi_smb_ids);
-
-static struct pci_driver pasemi_smb_driver = {
-	.name		= "i2c-pasemi",
-	.id_table	= pasemi_smb_ids,
-	.probe		= pasemi_smb_probe,
-	.remove		= pasemi_smb_remove,
-};
-
-module_pci_driver(pasemi_smb_driver);
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR ("Olof Johansson <olof@lixom.net>");
-MODULE_DESCRIPTION("PA Semi PWRficient SMBus driver");

@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/atomic.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/i2c-smbus.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+
+struct pasemi_smbus {
+	struct device		*dev;
+	struct i2c_adapter	 adapter;
+	void __iomem		*ioaddr;
+	unsigned long		 base;
+	int			 size;
+};
+
+int pasemi_i2c_common_probe(struct pasemi_smbus *smbus);

@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2006-2007 PA Semi, Inc
+ *
+ * SMBus host driver for PA Semi PWRficient
+ */
+
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/kernel.h>
+#include <linux/stddef.h>
+#include <linux/sched.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+
+#include "i2c-pasemi-core.h"
+
+static struct pci_driver pasemi_smb_pci_driver;
+
+static int pasemi_smb_pci_probe(struct pci_dev *dev,
+				      const struct pci_device_id *id)
+{
+	struct pasemi_smbus *smbus;
+	int error;
+
+	if (!(pci_resource_flags(dev, 0) & IORESOURCE_IO))
+		return -ENODEV;
+
+	smbus = kzalloc(sizeof(struct pasemi_smbus), GFP_KERNEL);
+	if (!smbus)
+		return -ENOMEM;
+
+	smbus->dev = &dev->dev;
+	smbus->base = pci_resource_start(dev, 0);
+	smbus->size = pci_resource_len(dev, 0);
+
+	if (!request_region(smbus->base, smbus->size,
+			    pasemi_smb_pci_driver.name)) {
+		error = -EBUSY;
+		goto out_kfree;
+	}
+
+	smbus->ioaddr = pci_iomap(dev, 0, 0);
+	if (!smbus->ioaddr) {
+		error = -EBUSY;
+		goto out_release_region;
+	}
+
+	error = pasemi_i2c_common_probe(smbus);
+	if (error)
+		goto out_ioport_unmap;
+
+	pci_set_drvdata(dev, smbus);
+
+	return 0;
+
+ out_ioport_unmap:
+	pci_iounmap(dev, smbus->ioaddr);
+ out_release_region:
+	release_region(smbus->base, smbus->size);
+ out_kfree:
+	kfree(smbus);
+	return error;
+}
+
+static void pasemi_smb_pci_remove(struct pci_dev *dev)
+{
+	struct pasemi_smbus *smbus = pci_get_drvdata(dev);
+
+	i2c_del_adapter(&smbus->adapter);
+	pci_iounmap(dev, smbus->ioaddr);
+	release_region(smbus->base, smbus->size);
+	kfree(smbus);
+}
+
+static const struct pci_device_id pasemi_smb_pci_ids[] = {
+	{ PCI_DEVICE(0x1959, 0xa003) },
+	{ 0, }
+};
+
+MODULE_DEVICE_TABLE(pci, pasemi_smb_pci_ids);
+
+static struct pci_driver pasemi_smb_pci_driver = {
+	.name		= "i2c-pasemi",
+	.id_table	= pasemi_smb_pci_ids,
+	.probe		= pasemi_smb_pci_probe,
+	.remove		= pasemi_smb_pci_remove,
+};
+
+module_pci_driver(pasemi_smb_pci_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Olof Johansson <olof@lixom.net>");
+MODULE_DESCRIPTION("PA Semi PWRficient SMBus driver");

@@ -61,6 +61,12 @@ static inline int reg_read(struct pasemi_smbus *smbus, int reg)
 #define TXFIFO_WR(smbus, reg)	reg_write((smbus), REG_MTXFIFO, (reg))
 #define RXFIFO_RD(smbus)	reg_read((smbus), REG_MRXFIFO)
 
+static void pasemi_reset(struct pasemi_smbus *smbus)
+{
+	reg_write(smbus, REG_CTL, (CTL_MTR | CTL_MRR |
+		  (CLK_100K_DIV & CTL_CLK_M)));
+}
+
 static void pasemi_smb_clear(struct pasemi_smbus *smbus)
 {
 	unsigned int status;

@@ -135,8 +141,7 @@ static int pasemi_i2c_xfer_msg(struct i2c_adapter *adapter,
 	return 0;
 
  reset_out:
-	reg_write(smbus, REG_CTL, (CTL_MTR | CTL_MRR |
-		  (CLK_100K_DIV & CTL_CLK_M)));
+	pasemi_reset(smbus);
 	return err;
 }
 

@@ -302,8 +307,7 @@ static int pasemi_smb_xfer(struct i2c_adapter *adapter,
 	return 0;
 
  reset_out:
-	reg_write(smbus, REG_CTL, (CTL_MTR | CTL_MRR |
-		  (CLK_100K_DIV & CTL_CLK_M)));
+	pasemi_reset(smbus);
 	return err;
 }
 

@@ -335,8 +339,7 @@ int pasemi_i2c_common_probe(struct pasemi_smbus *smbus)
 	/* set up the sysfs linkage to our parent device */
 	smbus->adapter.dev.parent = smbus->dev;
 
-	reg_write(smbus, REG_CTL, (CTL_MTR | CTL_MRR |
-		  (CLK_100K_DIV & CTL_CLK_M)));
+	pasemi_reset(smbus);
 
 	error = i2c_add_adapter(&smbus->adapter);
 	if (error)

@@ -39,9 +39,6 @@
 #define CTL_MTR		0x00000200
 #define CTL_CLK_M	0x000000ff
 
-#define CLK_100K_DIV	84
-#define CLK_400K_DIV	21
-
 static inline void reg_write(struct pasemi_smbus *smbus, int reg, int val)
 {
 	dev_dbg(smbus->dev, "smbus write reg %lx val %08x\n",

@@ -63,8 +60,9 @@ static inline int reg_read(struct pasemi_smbus *smbus, int reg)
 
 static void pasemi_reset(struct pasemi_smbus *smbus)
 {
-	reg_write(smbus, REG_CTL, (CTL_MTR | CTL_MRR |
-		  (CLK_100K_DIV & CTL_CLK_M)));
+	u32 val = (CTL_MTR | CTL_MRR | (smbus->clk_div & CTL_CLK_M));
+
+	reg_write(smbus, REG_CTL, val);
 }
 
 static void pasemi_smb_clear(struct pasemi_smbus *smbus)

@@ -14,6 +14,7 @@ struct pasemi_smbus {
 	void __iomem		*ioaddr;
 	unsigned long		 base;
 	int			 size;
+	unsigned int		 clk_div;
 };
 
 int pasemi_i2c_common_probe(struct pasemi_smbus *smbus);

@@ -17,6 +17,9 @@
 
 #include "i2c-pasemi-core.h"
 
+#define CLK_100K_DIV	84
+#define CLK_400K_DIV	21
+
 static struct pci_driver pasemi_smb_pci_driver;
 
 static int pasemi_smb_pci_probe(struct pci_dev *dev,

@@ -35,6 +38,7 @@ static int pasemi_smb_pci_probe(struct pci_dev *dev,
 	smbus->dev = &dev->dev;
 	smbus->base = pci_resource_start(dev, 0);
 	smbus->size = pci_resource_len(dev, 0);
+	smbus->clk_div = CLK_100K_DIV;
 
 	if (!request_region(smbus->base, smbus->size,
 			    pasemi_smb_pci_driver.name)) {

@@ -41,8 +41,7 @@
 
 static inline void reg_write(struct pasemi_smbus *smbus, int reg, int val)
 {
-	dev_dbg(smbus->dev, "smbus write reg %lx val %08x\n",
-		smbus->base + reg, val);
+	dev_dbg(smbus->dev, "smbus write reg %x val %08x\n", reg, val);
 	iowrite32(val, smbus->ioaddr + reg);
 }
 

@@ -50,8 +49,7 @@ static inline int reg_read(struct pasemi_smbus *smbus, int reg)
 {
 	int ret;
 	ret = ioread32(smbus->ioaddr + reg);
-	dev_dbg(smbus->dev, "smbus read reg %lx val %08x\n",
-		smbus->base + reg, ret);
+	dev_dbg(smbus->dev, "smbus read reg %x val %08x\n", reg, ret);
 	return ret;
 }
 

@@ -339,7 +337,7 @@ int pasemi_i2c_common_probe(struct pasemi_smbus *smbus)
 
 	pasemi_reset(smbus);
 
-	error = i2c_add_adapter(&smbus->adapter);
+	error = devm_i2c_add_adapter(smbus->dev, &smbus->adapter);
 	if (error)
 		return error;
 

@@ -12,8 +12,6 @@ struct pasemi_smbus {
 	struct device		*dev;
 	struct i2c_adapter	 adapter;
 	void __iomem		*ioaddr;
-	unsigned long		 base;
-	int			 size;
 	unsigned int		 clk_div;
 };
 

@@ -26,57 +26,37 @@ static int pasemi_smb_pci_probe(struct pci_dev *dev,
 				      const struct pci_device_id *id)
 {
 	struct pasemi_smbus *smbus;
+	unsigned long base;
+	int size;
 	int error;
 
 	if (!(pci_resource_flags(dev, 0) & IORESOURCE_IO))
 		return -ENODEV;
 
-	smbus = kzalloc(sizeof(struct pasemi_smbus), GFP_KERNEL);
+	smbus = devm_kzalloc(&dev->dev, sizeof(*smbus), GFP_KERNEL);
 	if (!smbus)
 		return -ENOMEM;
 
 	smbus->dev = &dev->dev;
-	smbus->base = pci_resource_start(dev, 0);
-	smbus->size = pci_resource_len(dev, 0);
+	base = pci_resource_start(dev, 0);
+	size = pci_resource_len(dev, 0);
 	smbus->clk_div = CLK_100K_DIV;
 
-	if (!request_region(smbus->base, smbus->size,
-			    pasemi_smb_pci_driver.name)) {
-		error = -EBUSY;
-		goto out_kfree;
-	}
+	if (!devm_request_region(&dev->dev, base, size,
+			    pasemi_smb_pci_driver.name))
+		return -EBUSY;
 
-	smbus->ioaddr = pci_iomap(dev, 0, 0);
-	if (!smbus->ioaddr) {
-		error = -EBUSY;
-		goto out_release_region;
-	}
+	smbus->ioaddr = pcim_iomap(dev, 0, 0);
+	if (!smbus->ioaddr)
+		return -EBUSY;
 
 	error = pasemi_i2c_common_probe(smbus);
 	if (error)
-		goto out_ioport_unmap;
+		return error;
 
 	pci_set_drvdata(dev, smbus);
 
 	return 0;
-
- out_ioport_unmap:
-	pci_iounmap(dev, smbus->ioaddr);
- out_release_region:
-	release_region(smbus->base, smbus->size);
- out_kfree:
-	kfree(smbus);
-	return error;
-}
-
-static void pasemi_smb_pci_remove(struct pci_dev *dev)
-{
-	struct pasemi_smbus *smbus = pci_get_drvdata(dev);
-
-	i2c_del_adapter(&smbus->adapter);
-	pci_iounmap(dev, smbus->ioaddr);
-	release_region(smbus->base, smbus->size);
-	kfree(smbus);
 }
 
 static const struct pci_device_id pasemi_smb_pci_ids[] = {

@@ -90,7 +70,6 @@ static struct pci_driver pasemi_smb_pci_driver = {
 	.name		= "i2c-pasemi",
 	.id_table	= pasemi_smb_pci_ids,
 	.probe		= pasemi_smb_pci_probe,
-	.remove		= pasemi_smb_pci_remove,
 };
 
 module_pci_driver(pasemi_smb_pci_driver);

@@ -1740,6 +1740,7 @@ F:	Documentation/devicetree/bindings/interrupt-controller/apple,aic.yaml
 F:	Documentation/devicetree/bindings/pci/apple,pcie.yaml
 F:	Documentation/devicetree/bindings/pinctrl/apple,pinctrl.yaml
 F:	arch/arm64/boot/dts/apple/
+F:	drivers/i2c/busses/i2c-pasemi-platform.c
 F:	drivers/irqchip/irq-apple-aic.c
 F:	include/dt-bindings/interrupt-controller/apple-aic.h
 F:	include/dt-bindings/pinctrl/apple.h

@@ -859,6 +859,17 @@ config I2C_PASEMI
 	help
 	  Supports the PA Semi PWRficient on-chip SMBus interfaces.
 
+config I2C_APPLE
+	tristate "Apple SMBus platform driver"
+	depends on ARCH_APPLE || COMPILE_TEST
+	default ARCH_APPLE
+	help
+	  Say Y here if you want to use the I2C controller present on Apple
+	  Silicon chips such as the M1.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called i2c-apple.
+
 config I2C_PCA_PLATFORM
 	tristate "PCA9564/PCA9665 as platform device"
 	select I2C_ALGOPCA

@@ -86,6 +86,8 @@ obj-$(CONFIG_I2C_OMAP)		+= i2c-omap.o
 obj-$(CONFIG_I2C_OWL)		+= i2c-owl.o
 i2c-pasemi-objs := i2c-pasemi-core.o i2c-pasemi-pci.o
 obj-$(CONFIG_I2C_PASEMI)	+= i2c-pasemi.o
+i2c-apple-objs := i2c-pasemi-core.o i2c-pasemi-platform.o
+obj-$(CONFIG_I2C_APPLE)	+= i2c-apple.o
 obj-$(CONFIG_I2C_PCA_PLATFORM)	+= i2c-pca-platform.o
 obj-$(CONFIG_I2C_PNX)		+= i2c-pnx.o
 obj-$(CONFIG_I2C_PXA)		+= i2c-pxa.o

@@ -0,0 +1,122 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2021 The Asahi Linux Contributors
+ *
+ * PA Semi PWRficient SMBus host driver for Apple SoCs
+ */
+
+#include <linux/clk.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+
+#include "i2c-pasemi-core.h"
+
+struct pasemi_platform_i2c_data {
+	struct pasemi_smbus smbus;
+	struct clk *clk_ref;
+};
+
+static int
+pasemi_platform_i2c_calc_clk_div(struct pasemi_platform_i2c_data *data,
+				 u32 frequency)
+{
+	unsigned long clk_rate = clk_get_rate(data->clk_ref);
+
+	if (!clk_rate)
+		return -EINVAL;
+
+	data->smbus.clk_div = DIV_ROUND_UP(clk_rate, 16 * frequency);
+	if (data->smbus.clk_div < 4)
+		return dev_err_probe(data->smbus.dev, -EINVAL,
+				     "Bus frequency %d is too fast.\n",
+				     frequency);
+	if (data->smbus.clk_div > 0xff)
+		return dev_err_probe(data->smbus.dev, -EINVAL,
+				     "Bus frequency %d is too slow.\n",
+				     frequency);
+
+	return 0;
+}
+
+static int pasemi_platform_i2c_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct pasemi_platform_i2c_data *data;
+	struct pasemi_smbus *smbus;
+	u32 frequency;
+	int error;
+
+	data = devm_kzalloc(dev, sizeof(struct pasemi_platform_i2c_data),
+			    GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	smbus = &data->smbus;
+	smbus->dev = dev;
+
+	smbus->ioaddr = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(smbus->ioaddr))
+		return PTR_ERR(smbus->ioaddr);
+
+	if (of_property_read_u32(dev->of_node, "clock-frequency", &frequency))
+		frequency = I2C_MAX_STANDARD_MODE_FREQ;
+
+	data->clk_ref = devm_clk_get(dev, NULL);
+	if (IS_ERR(data->clk_ref))
+		return PTR_ERR(data->clk_ref);
+
+	error = clk_prepare_enable(data->clk_ref);
+	if (error)
+		return error;
+
+	error = pasemi_platform_i2c_calc_clk_div(data, frequency);
+	if (error)
+		goto out_clk_disable;
+
+	smbus->adapter.dev.of_node = pdev->dev.of_node;
+	error = pasemi_i2c_common_probe(smbus);
+	if (error)
+		goto out_clk_disable;
+
+	platform_set_drvdata(pdev, data);
+
+	return 0;
+
+out_clk_disable:
+	clk_disable_unprepare(data->clk_ref);
+
+	return error;
+}
+
+static int pasemi_platform_i2c_remove(struct platform_device *pdev)
+{
+	struct pasemi_platform_i2c_data *data = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(data->clk_ref);
+	return 0;
+}
+
+static const struct of_device_id pasemi_platform_i2c_of_match[] = {
+	{ .compatible = "apple,t8103-i2c" },
+	{ .compatible = "apple,i2c" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, pasemi_platform_i2c_of_match);
+
+static struct platform_driver pasemi_platform_i2c_driver = {
+	.driver	= {
+		.name			= "i2c-apple",
+		.of_match_table		= pasemi_platform_i2c_of_match,
+	},
+	.probe	= pasemi_platform_i2c_probe,
+	.remove	= pasemi_platform_i2c_remove,
+};
+module_platform_driver(pasemi_platform_i2c_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Sven Peter <sven@svenpeter.dev>");
+MODULE_DESCRIPTION("Apple/PASemi SMBus platform driver");

@@ -22,6 +22,7 @@
 #define REG_MRXFIFO	0x04
 #define REG_SMSTA	0x14
 #define REG_CTL		0x1c
+#define REG_REV		0x28
 
 /* Register defs */
 #define MTXFIFO_READ	0x00000400

@@ -37,6 +38,7 @@
 
 #define CTL_MRR		0x00000400
 #define CTL_MTR		0x00000200
+#define CTL_EN		0x00000800
 #define CTL_CLK_M	0x000000ff
 
 static inline void reg_write(struct pasemi_smbus *smbus, int reg, int val)

@@ -60,6 +62,9 @@ static void pasemi_reset(struct pasemi_smbus *smbus)
 {
 	u32 val = (CTL_MTR | CTL_MRR | (smbus->clk_div & CTL_CLK_M));
 
+	if (smbus->hw_rev >= 6)
+		val |= CTL_EN;
+
 	reg_write(smbus, REG_CTL, val);
 }
 

@@ -335,6 +340,9 @@ int pasemi_i2c_common_probe(struct pasemi_smbus *smbus)
 	/* set up the sysfs linkage to our parent device */
 	smbus->adapter.dev.parent = smbus->dev;
 
+	if (smbus->hw_rev != PASEMI_HW_REV_PCI)
+		smbus->hw_rev = reg_read(smbus, REG_REV);
+
 	pasemi_reset(smbus);
 
 	error = devm_i2c_add_adapter(smbus->dev, &smbus->adapter);

@@ -8,11 +8,14 @@
 #include <linux/io.h>
 #include <linux/kernel.h>
 
+#define PASEMI_HW_REV_PCI -1
+
 struct pasemi_smbus {
 	struct device		*dev;
 	struct i2c_adapter	 adapter;
 	void __iomem		*ioaddr;
 	unsigned int		 clk_div;
+	int			 hw_rev;
 };
 
 int pasemi_i2c_common_probe(struct pasemi_smbus *smbus);

@@ -42,6 +42,12 @@ static int pasemi_smb_pci_probe(struct pci_dev *dev,
 	size = pci_resource_len(dev, 0);
 	smbus->clk_div = CLK_100K_DIV;
 
+	/*
+	 * The original PASemi PCI controllers don't have a register for
+	 * their HW revision.
+	 */
+	smbus->hw_rev = PASEMI_HW_REV_PCI;
+
 	if (!devm_request_region(&dev->dev, base, size,
 			    pasemi_smb_pci_driver.name))
 		return -EBUSY;