Merge tag 'i2c-for-7.1-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c updates from Wolfram Sang:
 "The biggest news in this pull request is that it will start the last
  cycle of me handling the I2C subsystem. From 7.2. on, I will pass
  maintainership to Andi Shyti who has been maintaining the I2C drivers
  for a while now and who has done a great job in doing so.

  We will use this cycle for a hopefully smooth transition. Thanks must
  go to Andi for stepping up! I will still be around for guidance.

  Updates:
   - generic cleanups in npcm7xx, qcom-cci, xiic and designware DT
     bindings
   - atr: use kzalloc_flex for alias pool allocation
   - ixp4xx: convert bindings to DT schema
   - ocores: use read_poll_timeout_atomic() for polling waits
   - qcom-geni: skip extra TX DMA TRE for single read messages
   - s3c24xx: validate SMBus block length before using it
   - spacemit: refactor xfer path and add K1 PIO support
   - tegra: identify DVC and VI with SoC data variants
   - tegra: support SoC-specific register offsets
   - xiic: switch to devres and generic fw properties
   - xiic: skip input clock setup on non-OF systems
   - various minor improvements in other drivers

  rtl9300:
   - add per-SoC callbacks and clock support for RTL9607C
   - add support for new 50 kHz and 2.5 MHz bus speeds
   - general refactoring in preparation for RTL9607C support

  New support:
   - DesignWare GOOG5000 (ACPI HID)
   - Intel Nova Lake (ACPI ID)
   - Realtek RTL9607C
   - SpacemiT K3 binding
   - Tegra410 register layout support"

* tag 'i2c-for-7.1-rc1-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: (40 commits)
  i2c: usbio: Add ACPI device-id for NVL platforms
  i2c: qcom-geni: Avoid extra TX DMA TRE for single read message in GPI mode
  i2c: atr: use kzalloc_flex
  i2c: spacemit: introduce pio for k1
  i2c: spacemit: move i2c_xfer_msg()
  i2c: xiic: skip input clock setup on non-OF systems
  i2c: xiic: use numbered adapter registration
  i2c: xiic: cosmetic: use resource format specifier in debug log
  i2c: xiic: cosmetic cleanup
  i2c: xiic: switch to generic device property accessors
  i2c: xiic: remove duplicate error message
  i2c: xiic: switch to devres managed APIs
  i2c: rtl9300: add RTL9607C i2c controller support
  i2c: rtl9300: introduce new function properties to driver data
  i2c: rtl9300: introduce clk struct for upcoming rtl9607 support
  dt-bindings: i2c: realtek,rtl9301-i2c: extend for clocks and RTL9607C support
  i2c: rtl9300: introduce a property for 8 bit width reg address
  i2c: rtl9300: introduce F_BUSY to the reg_fields struct
  i2c: rtl9300: introduce max length property to driver data
  i2c: rtl9300: split data_reg into read and write reg
  ...

24 files changed, 970 insertions, 393 deletions

diff --git a/Documentation/devicetree/bindings/i2c/i2c-iop3xx.txt b/Documentation/devicetree/bindings/i2c/i2c-iop3xx.txt
deleted file mode 100644
index dcc8390e0d24..000000000000
--- a/Documentation/devicetree/bindings/i2c/i2c-iop3xx.txt
+++ /dev/null
@@ -1,20 +0,0 @@
-i2c Controller on XScale platforms such as IOP3xx and IXP4xx
-
-Required properties:
-- compatible : Must be one of
-  "intel,iop3xx-i2c"
-  "intel,ixp4xx-i2c";
-- reg
-- #address-cells = <1>;
-- #size-cells = <0>;
-
-Optional properties:
-- Child nodes conforming to i2c bus binding
-
-Example:
-
-i2c@c8011000 {
-	compatible = "intel,ixp4xx-i2c";
-	reg = <0xc8011000 0x18>;
-	interrupts = <33 IRQ_TYPE_LEVEL_LOW>;
-};
diff --git a/Documentation/devicetree/bindings/i2c/intel,ixp4xx-i2c.yaml b/Documentation/devicetree/bindings/i2c/intel,ixp4xx-i2c.yaml
new file mode 100644
index 000000000000..15ef510f6fd8
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/intel,ixp4xx-i2c.yaml
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/i2c/intel,ixp4xx-i2c.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: I2c Controller on XScale platforms such as IOP3xx and IXP4xx
+
+maintainers:
+  - Andi Shyti <andi.shyti@kernel.org>
+
+allOf:
+  - $ref: /schemas/i2c/i2c-controller.yaml#
+
+properties:
+  compatible:
+    enum:
+      - intel,iop3xx-i2c
+      - intel,ixp4xx-i2c
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2c@c8011000 {
+        compatible = "intel,ixp4xx-i2c";
+        reg = <0xc8011000 0x18>;
+        interrupts = <33 IRQ_TYPE_LEVEL_LOW>;
+    };
diff --git a/Documentation/devicetree/bindings/i2c/qcom,i2c-cci.yaml b/Documentation/devicetree/bindings/i2c/qcom,i2c-cci.yaml
index 399a09409e07..7c497a358e1d 100644
--- a/Documentation/devicetree/bindings/i2c/qcom,i2c-cci.yaml
+++ b/Documentation/devicetree/bindings/i2c/qcom,i2c-cci.yaml
@@ -27,6 +27,7 @@ properties:
       - items:
           - enum:
               - qcom,kaanapali-cci
+              - qcom,milos-cci
               - qcom,qcm2290-cci
               - qcom,qcs8300-cci
               - qcom,sa8775p-cci
@@ -34,6 +35,7 @@ properties:
               - qcom,sc8280xp-cci
               - qcom,sdm670-cci
               - qcom,sdm845-cci
+              - qcom,sm6150-cci
               - qcom,sm6350-cci
               - qcom,sm8250-cci
               - qcom,sm8450-cci
@@ -251,6 +253,7 @@ allOf:
           contains:
             enum:
               - qcom,sa8775p-cci
+              - qcom,sm6150-cci
               - qcom,sm8550-cci
               - qcom,sm8650-cci
               - qcom,x1e80100-cci
@@ -265,6 +268,23 @@ allOf:
             - const: cpas_ahb
             - const: cci
 
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - qcom,milos-cci
+    then:
+      properties:
+        clocks:
+          minItems: 3
+          maxItems: 3
+        clock-names:
+          items:
+            - const: soc_ahb
+            - const: cpas_ahb
+            - const: cci
+
 additionalProperties: false
 
 examples:
diff --git a/Documentation/devicetree/bindings/i2c/realtek,rtl9301-i2c.yaml b/Documentation/devicetree/bindings/i2c/realtek,rtl9301-i2c.yaml
index f9a449fee2b0..5873cfdc5b3e 100644
--- a/Documentation/devicetree/bindings/i2c/realtek,rtl9301-i2c.yaml
+++ b/Documentation/devicetree/bindings/i2c/realtek,rtl9301-i2c.yaml
@@ -15,6 +15,8 @@ description:
   assigned to either I2C controller.
   RTL9310 SoCs have equal capabilities but support 12 common SDA lines which
   can be assigned to either I2C controller.
+  RTL9607C SoCs have equal capabilities but each controller only supports 1
+  SCL/SDA line.
 
 properties:
   compatible:
@@ -34,6 +36,7 @@ properties:
       - enum:
           - realtek,rtl9301-i2c
           - realtek,rtl9310-i2c
+          - realtek,rtl9607-i2c
 
   reg:
     items:
@@ -51,6 +54,9 @@ properties:
       The SCL line number of this I2C controller.
     enum: [ 0, 1 ]
 
+  clocks:
+    maxItems: 1
+
 patternProperties:
   '^i2c@[0-9ab]$':
     $ref: /schemas/i2c/i2c-controller.yaml
@@ -81,6 +87,15 @@ allOf:
     then:
       patternProperties:
         '^i2c@[89ab]$': false
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: realtek,rtl9607-i2c
+    then:
+      required:
+        - realtek,scl
+        - clocks
 
 required:
   - compatible
diff --git a/Documentation/devicetree/bindings/i2c/renesas,riic.yaml b/Documentation/devicetree/bindings/i2c/renesas,riic.yaml
index 6876eade431b..ae1f71eadc66 100644
--- a/Documentation/devicetree/bindings/i2c/renesas,riic.yaml
+++ b/Documentation/devicetree/bindings/i2c/renesas,riic.yaml
@@ -25,6 +25,7 @@ properties:
       - items:
           - enum:
               - renesas,riic-r9a08g045   # RZ/G3S
+              - renesas,riic-r9a08g046   # RZ/G3L
               - renesas,riic-r9a09g047   # RZ/G3E
               - renesas,riic-r9a09g056   # RZ/V2N
           - const: renesas,riic-r9a09g057   # RZ/V2H(P)
diff --git a/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml b/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml
index 082fdc2e69ea..467bdcbb8538 100644
--- a/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml
+++ b/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml
@@ -32,8 +32,6 @@ properties:
           - const: renesas,r9a06g032-i2c  # RZ/N1D
           - const: renesas,rzn1-i2c       # RZ/N1
           - const: snps,designware-i2c
-      - description: Baikal-T1 SoC System I2C controller
-        const: baikal,bt1-sys-i2c
       - description: Mobileye EyeQ DesignWare I2C controller
         items:
           - enum:
diff --git a/Documentation/devicetree/bindings/i2c/spacemit,k1-i2c.yaml b/Documentation/devicetree/bindings/i2c/spacemit,k1-i2c.yaml
index 5896fb120501..8c04c675b25e 100644
--- a/Documentation/devicetree/bindings/i2c/spacemit,k1-i2c.yaml
+++ b/Documentation/devicetree/bindings/i2c/spacemit,k1-i2c.yaml
@@ -14,7 +14,11 @@ allOf:
 
 properties:
   compatible:
-    const: spacemit,k1-i2c
+    oneOf:
+      - items:
+          - const: spacemit,k3-i2c
+          - const: spacemit,k1-i2c
+      - const: spacemit,k1-i2c
 
   reg:
     maxItems: 1
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 7cb6b9b864a7..8c935f867a37 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -1211,8 +1211,7 @@ config I2C_SYNQUACER
 
 config I2C_TEGRA
 	tristate "NVIDIA Tegra internal I2C controller"
-	depends on ARCH_TEGRA || (COMPILE_TEST && (ARC || ARM || ARM64 || M68K || RISCV || SUPERH || SPARC))
-	# COMPILE_TEST needs architectures with readsX()/writesX() primitives
+	depends on ARCH_TEGRA || COMPILE_TEST
 	depends on PINCTRL
 	# ARCH_TEGRA implies PINCTRL, but the COMPILE_TEST side doesn't.
 	help
diff --git a/drivers/i2c/busses/i2c-cp2615.c b/drivers/i2c/busses/i2c-cp2615.c
index 8212875700e1..951de6249834 100644
--- a/drivers/i2c/busses/i2c-cp2615.c
+++ b/drivers/i2c/busses/i2c-cp2615.c
@@ -270,8 +270,7 @@ static struct i2c_adapter_quirks cp2615_i2c_quirks = {
 	.max_comb_2nd_msg_len = MAX_I2C_SIZE
 };
 
-static void
-cp2615_i2c_remove(struct usb_interface *usbif)
+static void cp2615_i2c_disconnect(struct usb_interface *usbif)
 {
 	struct i2c_adapter *adap = usb_get_intfdata(usbif);
 
@@ -328,7 +327,7 @@ MODULE_DEVICE_TABLE(usb, id_table);
 static struct usb_driver cp2615_i2c_driver = {
 	.name = "i2c-cp2615",
 	.probe = cp2615_i2c_probe,
-	.disconnect = cp2615_i2c_remove,
+	.disconnect = cp2615_i2c_disconnect,
 	.id_table = id_table,
 };
 
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 426ffec06e22..3351c4a9ef11 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -268,6 +268,7 @@ static const struct acpi_device_id dw_i2c_acpi_match[] = {
 	{ "AMDI0510", 0 },
 	{ "APMC0D0F", 0 },
 	{ "FUJI200B", 0 },
+	{ "GOOG5000", 0 },
 	{ "HISI02A1", 0 },
 	{ "HISI02A2", 0 },
 	{ "HISI02A3", 0 },
diff --git a/drivers/i2c/busses/i2c-diolan-u2c.c b/drivers/i2c/busses/i2c-diolan-u2c.c
index 077b093ba834..d502f6e4732f 100644
--- a/drivers/i2c/busses/i2c-diolan-u2c.c
+++ b/drivers/i2c/busses/i2c-diolan-u2c.c
@@ -427,12 +427,6 @@ static const struct usb_device_id diolan_u2c_table[] = {
 
 MODULE_DEVICE_TABLE(usb, diolan_u2c_table);
 
-static void diolan_u2c_free(struct i2c_diolan_u2c *dev)
-{
-	usb_put_dev(dev->usb_dev);
-	kfree(dev);
-}
-
 static int diolan_u2c_probe(struct usb_interface *interface,
 			    const struct usb_device_id *id)
 {
@@ -453,7 +447,7 @@ static int diolan_u2c_probe(struct usb_interface *interface,
 	dev->ep_out = hostif->endpoint[0].desc.bEndpointAddress;
 	dev->ep_in = hostif->endpoint[1].desc.bEndpointAddress;
 
-	dev->usb_dev = usb_get_dev(interface_to_usbdev(interface));
+	dev->usb_dev = interface_to_usbdev(interface);
 	dev->interface = interface;
 
 	/* save our data pointer in this interface device */
@@ -488,7 +482,7 @@ static int diolan_u2c_probe(struct usb_interface *interface,
 
 error_free:
 	usb_set_intfdata(interface, NULL);
-	diolan_u2c_free(dev);
+	kfree(dev);
 error:
 	return ret;
 }
@@ -499,7 +493,7 @@ static void diolan_u2c_disconnect(struct usb_interface *interface)
 
 	i2c_del_adapter(&dev->adapter);
 	usb_set_intfdata(interface, NULL);
-	diolan_u2c_free(dev);
+	kfree(dev);
 
 	dev_dbg(&interface->dev, "disconnected\n");
 }
diff --git a/drivers/i2c/busses/i2c-k1.c b/drivers/i2c/busses/i2c-k1.c
index 6e93da576bbd..9152cf436bea 100644
--- a/drivers/i2c/busses/i2c-k1.c
+++ b/drivers/i2c/busses/i2c-k1.c
@@ -98,6 +98,10 @@
 
 #define SPACEMIT_BUS_RESET_CLK_CNT_MAX		9
 
+#define SPACEMIT_WAIT_TIMEOUT      1000 /* ms */
+#define SPACEMIT_POLL_TIMEOUT      1000 /* us */
+#define SPACEMIT_POLL_INTERVAL	   30	/* us */
+
 enum spacemit_i2c_state {
 	SPACEMIT_STATE_IDLE,
 	SPACEMIT_STATE_START,
@@ -126,6 +130,7 @@ struct spacemit_i2c_dev {
 
 	enum spacemit_i2c_state state;
 	bool read;
+	bool use_pio;
 	struct completion complete;
 	u32 status;
 };
@@ -172,6 +177,14 @@ static int spacemit_i2c_handle_err(struct spacemit_i2c_dev *i2c)
 	return i2c->status & SPACEMIT_SR_ACKNAK ? -ENXIO : -EIO;
 }
 
+static inline void spacemit_i2c_delay(struct spacemit_i2c_dev *i2c, unsigned int us)
+{
+	if (i2c->use_pio)
+		udelay(us);
+	else
+		fsleep(us);
+}
+
 static void spacemit_i2c_conditionally_reset_bus(struct spacemit_i2c_dev *i2c)
 {
 	u32 status;
@@ -183,7 +196,8 @@ static void spacemit_i2c_conditionally_reset_bus(struct spacemit_i2c_dev *i2c)
 		return;
 
 	spacemit_i2c_reset(i2c);
-	usleep_range(10, 20);
+
+	spacemit_i2c_delay(i2c, 10);
 
 	for (clk_cnt = 0; clk_cnt < SPACEMIT_BUS_RESET_CLK_CNT_MAX; clk_cnt++) {
 		status = readl(i2c->base + SPACEMIT_IBMR);
@@ -212,9 +226,15 @@ static int spacemit_i2c_wait_bus_idle(struct spacemit_i2c_dev *i2c)
 	if (!(val & (SPACEMIT_SR_UB | SPACEMIT_SR_IBB)))
 		return 0;
 
-	ret = readl_poll_timeout(i2c->base + SPACEMIT_ISR,
-				 val, !(val & (SPACEMIT_SR_UB | SPACEMIT_SR_IBB)),
-				 1500, SPACEMIT_I2C_BUS_BUSY_TIMEOUT);
+	if (i2c->use_pio)
+		ret = readl_poll_timeout_atomic(i2c->base + SPACEMIT_ISR,
+						val, !(val & (SPACEMIT_SR_UB | SPACEMIT_SR_IBB)),
+						1500, SPACEMIT_I2C_BUS_BUSY_TIMEOUT);
+	else
+		ret = readl_poll_timeout(i2c->base + SPACEMIT_ISR,
+					 val, !(val & (SPACEMIT_SR_UB | SPACEMIT_SR_IBB)),
+					 1500, SPACEMIT_I2C_BUS_BUSY_TIMEOUT);
+
 	if (ret)
 		spacemit_i2c_reset(i2c);
 
@@ -226,7 +246,7 @@ static void spacemit_i2c_check_bus_release(struct spacemit_i2c_dev *i2c)
 	/* in case bus is not released after transfer completes */
 	if (readl(i2c->base + SPACEMIT_ISR) & SPACEMIT_SR_EBB) {
 		spacemit_i2c_conditionally_reset_bus(i2c);
-		usleep_range(90, 150);
+		spacemit_i2c_delay(i2c, 90);
 	}
 }
 
@@ -238,25 +258,33 @@ spacemit_i2c_clear_int_status(struct spacemit_i2c_dev *i2c, u32 mask)
 
 static void spacemit_i2c_init(struct spacemit_i2c_dev *i2c)
 {
-	u32 val;
-
-	/*
-	 * Unmask interrupt bits for all xfer mode:
-	 * bus error, arbitration loss detected.
-	 * For transaction complete signal, we use master stop
-	 * interrupt, so we don't need to unmask SPACEMIT_CR_TXDONEIE.
-	 */
-	val = SPACEMIT_CR_BEIE | SPACEMIT_CR_ALDIE;
-
-	/*
-	 * Unmask interrupt bits for interrupt xfer mode:
-	 * When IDBR receives a byte, an interrupt is triggered.
-	 *
-	 * For the tx empty interrupt, it will be enabled in the
-	 * i2c_start function.
-	 * Otherwise, it will cause an erroneous empty interrupt before i2c_start.
-	 */
-	val |= SPACEMIT_CR_DRFIE;
+	u32 val = 0;
+
+	if (!i2c->use_pio) {
+		/*
+		 * Enable interrupt bits for all xfer mode:
+		 * bus error, arbitration loss detected.
+		 */
+		val |= SPACEMIT_CR_BEIE | SPACEMIT_CR_ALDIE;
+
+		/*
+		 * Unmask interrupt bits for interrupt xfer mode:
+		 * When IDBR receives a byte, an interrupt is triggered.
+		 *
+		 * For the tx empty interrupt, it will be enabled in the
+		 * i2c_start().
+		 * We don't want a TX empty interrupt until we start
+		 * a transfer in i2c_start().
+		 */
+		val |= SPACEMIT_CR_DRFIE;
+
+		/*
+		 * Enable master stop interrupt bit.
+		 * For transaction complete signal, we use master stop
+		 * interrupt, so we don't need to unmask SPACEMIT_CR_TXDONEIE.
+		 */
+		val |= SPACEMIT_CR_MSDIE;
+	}
 
 	if (i2c->clock_freq == SPACEMIT_I2C_MAX_FAST_MODE_FREQ)
 		val |= SPACEMIT_CR_MODE_FAST;
@@ -268,7 +296,7 @@ static void spacemit_i2c_init(struct spacemit_i2c_dev *i2c)
 	val |= SPACEMIT_CR_SCLE;
 
 	/* enable master stop detected */
-	val |= SPACEMIT_CR_MSDE | SPACEMIT_CR_MSDIE;
+	val |= SPACEMIT_CR_MSDE;
 
 	writel(val, i2c->base + SPACEMIT_ICR);
 
@@ -301,39 +329,13 @@ static void spacemit_i2c_start(struct spacemit_i2c_dev *i2c)
 	/* send start pulse */
 	val = readl(i2c->base + SPACEMIT_ICR);
 	val &= ~SPACEMIT_CR_STOP;
-	val |= SPACEMIT_CR_START | SPACEMIT_CR_TB | SPACEMIT_CR_DTEIE;
-	writel(val, i2c->base + SPACEMIT_ICR);
-}
-
-static int spacemit_i2c_xfer_msg(struct spacemit_i2c_dev *i2c)
-{
-	unsigned long time_left;
-	struct i2c_msg *msg;
+	val |= SPACEMIT_CR_START | SPACEMIT_CR_TB;
 
-	for (i2c->msg_idx = 0; i2c->msg_idx < i2c->msg_num; i2c->msg_idx++) {
-		msg = &i2c->msgs[i2c->msg_idx];
-		i2c->msg_buf = msg->buf;
-		i2c->unprocessed = msg->len;
-		i2c->status = 0;
-
-		reinit_completion(&i2c->complete);
-
-		spacemit_i2c_start(i2c);
-
-		time_left = wait_for_completion_timeout(&i2c->complete,
-							i2c->adapt.timeout);
-		if (!time_left) {
-			dev_err(i2c->dev, "msg completion timeout\n");
-			spacemit_i2c_conditionally_reset_bus(i2c);
-			spacemit_i2c_reset(i2c);
-			return -ETIMEDOUT;
-		}
-
-		if (i2c->status & SPACEMIT_SR_ERR)
-			return spacemit_i2c_handle_err(i2c);
-	}
+	/* Enable the TX empty interrupt */
+	if (!i2c->use_pio)
+		val |= SPACEMIT_CR_DTEIE;
 
-	return 0;
+	writel(val, i2c->base + SPACEMIT_ICR);
 }
 
 static bool spacemit_i2c_is_last_msg(struct spacemit_i2c_dev *i2c)
@@ -347,8 +349,23 @@ static bool spacemit_i2c_is_last_msg(struct spacemit_i2c_dev *i2c)
 	return !i2c->unprocessed;
 }
 
+static inline void spacemit_i2c_complete(struct spacemit_i2c_dev *i2c)
+{
+	/* SPACEMIT_STATE_IDLE avoids triggering the next byte */
+	i2c->state = SPACEMIT_STATE_IDLE;
+
+	if (i2c->use_pio)
+		return;
+
+	complete(&i2c->complete);
+}
+
 static void spacemit_i2c_handle_write(struct spacemit_i2c_dev *i2c)
 {
+	/* If there's no space in the IDBR, we're done */
+	if (!(i2c->status & SPACEMIT_SR_ITE))
+		return;
+
 	/* if transfer completes, SPACEMIT_ISR will handle it */
 	if (i2c->status & SPACEMIT_SR_MSD)
 		return;
@@ -359,16 +376,19 @@ static void spacemit_i2c_handle_write(struct spacemit_i2c_dev *i2c)
 		return;
 	}
 
-	/* SPACEMIT_STATE_IDLE avoids trigger next byte */
-	i2c->state = SPACEMIT_STATE_IDLE;
-	complete(&i2c->complete);
+	spacemit_i2c_complete(i2c);
 }
 
 static void spacemit_i2c_handle_read(struct spacemit_i2c_dev *i2c)
 {
+	/* If there's nothing in the IDBR, we're done */
+	if (!(i2c->status & SPACEMIT_SR_IRF))
+		return;
+
 	if (i2c->unprocessed) {
 		*i2c->msg_buf++ = readl(i2c->base + SPACEMIT_IDBR);
 		i2c->unprocessed--;
+		return;
 	}
 
 	/* if transfer completes, SPACEMIT_ISR will handle it */
@@ -379,9 +399,7 @@ static void spacemit_i2c_handle_read(struct spacemit_i2c_dev *i2c)
 	if (i2c->unprocessed)
 		return;
 
-	/* SPACEMIT_STATE_IDLE avoids trigger next byte */
-	i2c->state = SPACEMIT_STATE_IDLE;
-	complete(&i2c->complete);
+	spacemit_i2c_complete(i2c);
 }
 
 static void spacemit_i2c_handle_start(struct spacemit_i2c_dev *i2c)
@@ -415,29 +433,16 @@ static void spacemit_i2c_err_check(struct spacemit_i2c_dev *i2c)
 
 	spacemit_i2c_clear_int_status(i2c, SPACEMIT_I2C_INT_STATUS_MASK);
 
-	i2c->state = SPACEMIT_STATE_IDLE;
-	complete(&i2c->complete);
+	spacemit_i2c_complete(i2c);
 }
 
-static irqreturn_t spacemit_i2c_irq_handler(int irq, void *devid)
+static void spacemit_i2c_handle_state(struct spacemit_i2c_dev *i2c)
 {
-	struct spacemit_i2c_dev *i2c = devid;
-	u32 status, val;
-
-	status = readl(i2c->base + SPACEMIT_ISR);
-	if (!status)
-		return IRQ_HANDLED;
-
-	i2c->status = status;
-
-	spacemit_i2c_clear_int_status(i2c, status);
+	u32 val;
 
 	if (i2c->status & SPACEMIT_SR_ERR)
 		goto err_out;
 
-	val = readl(i2c->base + SPACEMIT_ICR);
-	val &= ~(SPACEMIT_CR_TB | SPACEMIT_CR_ACKNAK | SPACEMIT_CR_STOP | SPACEMIT_CR_START);
-
 	switch (i2c->state) {
 	case SPACEMIT_STATE_START:
 		spacemit_i2c_handle_start(i2c);
@@ -453,7 +458,12 @@ static irqreturn_t spacemit_i2c_irq_handler(int irq, void *devid)
 	}
 
 	if (i2c->state != SPACEMIT_STATE_IDLE) {
-		val |= SPACEMIT_CR_TB | SPACEMIT_CR_ALDIE;
+		val = readl(i2c->base + SPACEMIT_ICR);
+		val &= ~(SPACEMIT_CR_TB | SPACEMIT_CR_ACKNAK |
+			 SPACEMIT_CR_STOP | SPACEMIT_CR_START);
+		val |= SPACEMIT_CR_TB;
+		if (!i2c->use_pio)
+			val |= SPACEMIT_CR_ALDIE;
 
 		if (spacemit_i2c_is_last_msg(i2c)) {
 			/* trigger next byte with stop */
@@ -467,6 +477,133 @@ static irqreturn_t spacemit_i2c_irq_handler(int irq, void *devid)
 
 err_out:
 	spacemit_i2c_err_check(i2c);
+}
+
+/*
+ * In PIO mode, this function is used as a replacement for
+ * wait_for_completion_timeout(), whose return value indicates
+ * the remaining time.
+ *
+ * We do not have a meaningful remaining-time value here, so
+ * return a non-zero value on success to indicate "not timed out".
+ * Returning 1 ensures callers treating the return value as
+ * time_left will not incorrectly report a timeout.
+ */
+static int spacemit_i2c_wait_pio_xfer(struct spacemit_i2c_dev *i2c)
+{
+	u32 mask, msec = jiffies_to_msecs(i2c->adapt.timeout);
+	ktime_t timeout = ktime_add_ms(ktime_get(), msec);
+	int ret;
+
+	mask = SPACEMIT_SR_IRF | SPACEMIT_SR_ITE;
+
+	do {
+		i2c->status = readl(i2c->base + SPACEMIT_ISR);
+
+		spacemit_i2c_clear_int_status(i2c, i2c->status);
+
+		if (i2c->status & mask)
+			spacemit_i2c_handle_state(i2c);
+		else
+			udelay(SPACEMIT_POLL_INTERVAL);
+	} while (i2c->unprocessed && ktime_compare(ktime_get(), timeout) < 0);
+
+	if (i2c->unprocessed)
+		return 0;
+
+	if (i2c->read)
+		return 1;
+
+	/*
+	 * If this is the last byte to write of the current message,
+	 * we have to wait here. Otherwise, control will proceed directly
+	 * to start(), which would overwrite the current data.
+	 */
+	ret = readl_poll_timeout_atomic(i2c->base + SPACEMIT_ISR,
+					i2c->status, i2c->status & SPACEMIT_SR_ITE,
+					SPACEMIT_POLL_INTERVAL, SPACEMIT_POLL_TIMEOUT);
+	if (ret)
+		return 0;
+
+	/*
+	 * For writes: in interrupt mode, an ITE (write-empty) interrupt is triggered
+	 * after the last byte, and the MSD-related handling takes place there.
+	 * In PIO mode, however, we need to explicitly call err_check() to emulate this
+	 * step, otherwise the next transfer will fail.
+	 */
+	if (i2c->msg_idx == i2c->msg_num - 1) {
+		mask = SPACEMIT_SR_MSD | SPACEMIT_SR_ERR;
+		/*
+		 * In some cases, MSD may not arrive immediately;
+		 * wait here to handle that.
+		 */
+		ret = readl_poll_timeout_atomic(i2c->base + SPACEMIT_ISR,
+						i2c->status, i2c->status & mask,
+						SPACEMIT_POLL_INTERVAL, SPACEMIT_POLL_TIMEOUT);
+		if (ret)
+			return 0;
+
+		spacemit_i2c_err_check(i2c);
+	}
+
+	return 1;
+}
+
+static int spacemit_i2c_wait_xfer_complete(struct spacemit_i2c_dev *i2c)
+{
+	if (i2c->use_pio)
+		return spacemit_i2c_wait_pio_xfer(i2c);
+
+	return wait_for_completion_timeout(&i2c->complete,
+					   i2c->adapt.timeout);
+}
+
+static int spacemit_i2c_xfer_msg(struct spacemit_i2c_dev *i2c)
+{
+	unsigned long time_left;
+	struct i2c_msg *msg;
+
+	for (i2c->msg_idx = 0; i2c->msg_idx < i2c->msg_num; i2c->msg_idx++) {
+		msg = &i2c->msgs[i2c->msg_idx];
+		i2c->msg_buf = msg->buf;
+		i2c->unprocessed = msg->len;
+		i2c->status = 0;
+
+		reinit_completion(&i2c->complete);
+
+		spacemit_i2c_start(i2c);
+
+		time_left = spacemit_i2c_wait_xfer_complete(i2c);
+
+		if (!time_left) {
+			dev_err(i2c->dev, "msg completion timeout\n");
+			spacemit_i2c_conditionally_reset_bus(i2c);
+			spacemit_i2c_reset(i2c);
+			return -ETIMEDOUT;
+		}
+
+		if (i2c->status & SPACEMIT_SR_ERR)
+			return spacemit_i2c_handle_err(i2c);
+	}
+
+	return 0;
+}
+
+static irqreturn_t spacemit_i2c_irq_handler(int irq, void *devid)
+{
+	struct spacemit_i2c_dev *i2c = devid;
+	u32 status;
+
+	status = readl(i2c->base + SPACEMIT_ISR);
+	if (!status)
+		return IRQ_HANDLED;
+
+	i2c->status = status;
+
+	spacemit_i2c_clear_int_status(i2c, status);
+
+	spacemit_i2c_handle_state(i2c);
+
 	return IRQ_HANDLED;
 }
 
@@ -475,6 +612,11 @@ static void spacemit_i2c_calc_timeout(struct spacemit_i2c_dev *i2c)
 	unsigned long timeout;
 	int idx = 0, cnt = 0;
 
+	if (i2c->use_pio) {
+		i2c->adapt.timeout = msecs_to_jiffies(SPACEMIT_WAIT_TIMEOUT);
+		return;
+	}
+
 	for (; idx < i2c->msg_num; idx++)
 		cnt += (i2c->msgs + idx)->len + 1;
 
@@ -487,11 +629,14 @@ static void spacemit_i2c_calc_timeout(struct spacemit_i2c_dev *i2c)
 	i2c->adapt.timeout = usecs_to_jiffies(timeout + USEC_PER_SEC / 10) / i2c->msg_num;
 }
 
-static int spacemit_i2c_xfer(struct i2c_adapter *adapt, struct i2c_msg *msgs, int num)
+static inline int
+spacemit_i2c_xfer_common(struct i2c_adapter *adapt, struct i2c_msg *msgs, int num, bool use_pio)
 {
 	struct spacemit_i2c_dev *i2c = i2c_get_adapdata(adapt);
 	int ret;
 
+	i2c->use_pio = use_pio;
+
 	i2c->msgs = msgs;
 	i2c->msg_num = num;
 
@@ -519,6 +664,16 @@ static int spacemit_i2c_xfer(struct i2c_adapter *adapt, struct i2c_msg *msgs, in
 	return ret < 0 ? ret : num;
 }
 
+static int spacemit_i2c_xfer(struct i2c_adapter *adapt, struct i2c_msg *msgs, int num)
+{
+	return spacemit_i2c_xfer_common(adapt, msgs, num, false);
+}
+
+static int spacemit_i2c_pio_xfer_atomic(struct i2c_adapter *adapt, struct i2c_msg *msgs, int num)
+{
+	return spacemit_i2c_xfer_common(adapt, msgs, num, true);
+}
+
 static u32 spacemit_i2c_func(struct i2c_adapter *adap)
 {
 	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
@@ -526,6 +681,7 @@ static u32 spacemit_i2c_func(struct i2c_adapter *adap)
 
 static const struct i2c_algorithm spacemit_i2c_algo = {
 	.xfer = spacemit_i2c_xfer,
+	.xfer_atomic = spacemit_i2c_pio_xfer_atomic,
 	.functionality = spacemit_i2c_func,
 };
 
diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
index 8b7e15240fb0..f667a873b81e 100644
--- a/drivers/i2c/busses/i2c-npcm7xx.c
+++ b/drivers/i2c/busses/i2c-npcm7xx.c
@@ -1384,7 +1384,7 @@ static irqreturn_t npcm_i2c_int_slave_handler(struct npcm_i2c *bus)
 		 */
 		bus->operation = I2C_NO_OPER;
 		bus->own_slave_addr = 0xFF;
-		i2c_slave_event(bus->slave, I2C_SLAVE_STOP, 0);
+		i2c_slave_event(bus->slave, I2C_SLAVE_STOP, NULL);
 		iowrite8(NPCM_I2CST_SLVSTP, bus->reg + NPCM_I2CST);
 		if (bus->fifo_use) {
 			npcm_i2c_clear_fifo_int(bus);
diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c
index 0f67e57cdeff..df6ebf32d6e8 100644
--- a/drivers/i2c/busses/i2c-ocores.c
+++ b/drivers/i2c/busses/i2c-ocores.c
@@ -24,6 +24,7 @@
 #include <linux/io.h>
 #include <linux/log2.h>
 #include <linux/spinlock.h>
+#include <linux/iopoll.h>
 #include <linux/jiffies.h>
 
 /*
@@ -258,7 +259,7 @@ static void ocores_process_timeout(struct ocores_i2c *i2c)
  * @reg: register to query
  * @mask: bitmask to apply on register value