[PATCH v3 0/3] Driver for the Apple SPMI controller

[PATCH v3 0/3] Driver for the Apple SPMI controller

[Sasha Finkelstein via B4 Relay]

Hi.

This patch series adds support for the SPMI controller persent in most
Apple SoCs. The drivers for the attached PMU and subdevices will be in
further patch series.

Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
---
Changes in v3:
- Inlined helpers, dropped unneccesary error prefixes
- Link to v2: https://lore.kernel.org/r/20250307-spmi-v2-0-eccdb06afb99@gmail.com

Changes in v2:
- Removed redundant error prints
- Various style fixes
- Better explanation of why the driver is needed
- Link to v1: https://lore.kernel.org/r/20250305-spmi-v1-0-c98f561fa99f@gmail.com

---
Jean-Francois Bortolotti (1):
      spmi: add a spmi driver for Apple SoC

Sasha Finkelstein (2):
      dt-bindings: spmi: Add Apple SPMI controller
      arm64: dts: apple: Add SPMI controller nodes

 .../devicetree/bindings/spmi/apple,spmi.yaml       |  49 ++++++
 MAINTAINERS                                        |   2 +
 arch/arm64/boot/dts/apple/t600x-die0.dtsi          |   7 +
 arch/arm64/boot/dts/apple/t8103.dtsi               |   8 +
 arch/arm64/boot/dts/apple/t8112.dtsi               |   7 +
 drivers/spmi/Kconfig                               |   8 +
 drivers/spmi/Makefile                              |   1 +
 drivers/spmi/spmi-apple-controller.c               | 168 +++++++++++++++++++++
 8 files changed, 250 insertions(+)
---
base-commit: 48a5eed9ad584315c30ed35204510536235ce402
change-id: 20250304-spmi-6d3c24b9027a

[PATCH v3 1/3] dt-bindings: spmi: Add Apple SPMI controller

[Sasha Finkelstein via B4 Relay]

From: Sasha Finkelstein <fnkl.kernel@gmail.com>

Add bindings for the SPMI controller present on most Apple SoCs

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Sven Peter <sven@svenpeter.dev>
Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
---
 .../devicetree/bindings/spmi/apple,spmi.yaml       | 49 ++++++++++++++++++++++
 MAINTAINERS                                        |  1 +
 2 files changed, 50 insertions(+)

diff --git a/Documentation/devicetree/bindings/spmi/apple,spmi.yaml b/Documentation/devicetree/bindings/spmi/apple,spmi.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..16bd7eb2b7af2c0b176f0e5b1970f4670af691da
--- /dev/null
+++ b/Documentation/devicetree/bindings/spmi/apple,spmi.yaml
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/spmi/apple,spmi.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Apple SPMI controller
+
+maintainers:
+  - Sasha Finkelstein <fnkl.kernel@gmail.com>
+
+description: A SPMI controller present on most Apple SoCs
+
+allOf:
+  - $ref: spmi.yaml#
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - apple,t8103-spmi
+          - apple,t6000-spmi
+          - apple,t8112-spmi
+      - const: apple,spmi
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/spmi/spmi.h>
+
+    spmi@920a1300 {
+        compatible = "apple,t6000-spmi", "apple,spmi";
+        reg = <0x920a1300 0x100>;
+        #address-cells = <2>;
+        #size-cells = <0>;
+
+        pmic@f {
+            reg = <0xf SPMI_USID>;
+            /* PMIC-specific properties */
+        };
+    };
diff --git a/MAINTAINERS b/MAINTAINERS
index 8e0736dc2ee0e33544fa373a4978b7dae18c040c..271ff8110df83c2d4fe7fbbfffc0a72259460bc5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2236,6 +2236,7 @@ F:	Documentation/devicetree/bindings/pci/apple,pcie.yaml
 F:	Documentation/devicetree/bindings/pinctrl/apple,pinctrl.yaml
 F:	Documentation/devicetree/bindings/power/apple*
 F:	Documentation/devicetree/bindings/pwm/apple,s5l-fpwm.yaml
+F:	Documentation/devicetree/bindings/spmi/apple,spmi.yaml
 F:	Documentation/devicetree/bindings/watchdog/apple,wdt.yaml
 F:	arch/arm64/boot/dts/apple/
 F:	drivers/bluetooth/hci_bcm4377.c

-- 
2.48.1

[PATCH v3 2/3] spmi: add a spmi driver for Apple SoC

[Sasha Finkelstein via B4 Relay]

From: Jean-Francois Bortolotti <jeff@borto.fr>

The connected PMU contains several useful nvmem cells such as RTC offset,
boot failure counters, reboot/shutdown selector, and a few others.
In addition M3+ machines have their USB-PD controller connected via SPMI.

Signed-off-by: Jean-Francois Bortolotti <jeff@borto.fr>
Reviewed-by: Sven Peter <sven@svenpeter.dev>
Co-developed-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
---
 MAINTAINERS                          |   1 +
 drivers/spmi/Kconfig                 |   8 ++
 drivers/spmi/Makefile                |   1 +
 drivers/spmi/spmi-apple-controller.c | 168 +++++++++++++++++++++++++++++++++++
 4 files changed, 178 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 271ff8110df83c2d4fe7fbbfffc0a72259460bc5..9006695261d29fbc1e15659c2b43d7afeee0b656 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2254,6 +2254,7 @@ F:	drivers/nvmem/apple-efuses.c
 F:	drivers/pinctrl/pinctrl-apple-gpio.c
 F:	drivers/pwm/pwm-apple.c
 F:	drivers/soc/apple/*
+F:	drivers/spmi/spmi-apple-controller.c
 F:	drivers/watchdog/apple_wdt.c
 F:	include/dt-bindings/interrupt-controller/apple-aic.h
 F:	include/dt-bindings/pinctrl/apple.h
diff --git a/drivers/spmi/Kconfig b/drivers/spmi/Kconfig
index 73780204631463631cabcbad5bf83e8dbbee94ce..9005fa91d9f4e541403ccc7bf84e0592402ac41e 100644
--- a/drivers/spmi/Kconfig
+++ b/drivers/spmi/Kconfig
@@ -11,6 +11,14 @@ menuconfig SPMI
 
 if SPMI
 
+config SPMI_APPLE
+	tristate "Apple SoC SPMI Controller platform driver"
+	depends on ARCH_APPLE || COMPILE_TEST
+	help
+	  If you say yes to this option, support will be included for the
+	  SPMI controller present on many Apple SoCs, including the
+	  t8103 (M1) and t600x (M1 Pro/Max).
+
 config SPMI_HISI3670
 	tristate "Hisilicon 3670 SPMI Controller"
 	select IRQ_DOMAIN_HIERARCHY
diff --git a/drivers/spmi/Makefile b/drivers/spmi/Makefile
index 7f152167bb05b2c24a0f9669f60278152898eebb..38ac635645ba65aa46cb5e8a50072ed9771e229b 100644
--- a/drivers/spmi/Makefile
+++ b/drivers/spmi/Makefile
@@ -4,6 +4,7 @@
 #
 obj-$(CONFIG_SPMI)	+= spmi.o spmi-devres.o
 
+obj-$(CONFIG_SPMI_APPLE)	+= spmi-apple-controller.o
 obj-$(CONFIG_SPMI_HISI3670)	+= hisi-spmi-controller.o
 obj-$(CONFIG_SPMI_MSM_PMIC_ARB)	+= spmi-pmic-arb.o
 obj-$(CONFIG_SPMI_MTK_PMIF)	+= spmi-mtk-pmif.o
diff --git a/drivers/spmi/spmi-apple-controller.c b/drivers/spmi/spmi-apple-controller.c
new file mode 100644
index 0000000000000000000000000000000000000000..697b3e8bb023566f17911fc222666d84f5e14c91
--- /dev/null
+++ b/drivers/spmi/spmi-apple-controller.c
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Apple SoC SPMI device driver
+ *
+ * Copyright The Asahi Linux Contributors
+ *
+ * Inspired by:
+ *		OpenBSD support Copyright (c) 2021 Mark Kettenis <kettenis@openbsd.org>
+ *		Correllium support Copyright (C) 2021 Corellium LLC
+ *		hisi-spmi-controller.c
+ *		spmi-pmic-arb.c Copyright (c) 2021, The Linux Foundation.
+ */
+
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/spmi.h>
+
+/* SPMI Controller Registers */
+#define SPMI_STATUS_REG 0
+#define SPMI_CMD_REG 0x4
+#define SPMI_RSP_REG 0x8
+
+#define SPMI_RX_FIFO_EMPTY BIT(24)
+
+#define REG_POLL_INTERVAL_US 10000
+#define REG_POLL_TIMEOUT_US (REG_POLL_INTERVAL_US * 5)
+
+struct apple_spmi {
+	void __iomem *regs;
+};
+
+#define poll_reg(spmi, reg, val, cond) \
+	readl_poll_timeout((spmi)->regs + (reg), (val), (cond), \
+			   REG_POLL_INTERVAL_US, REG_POLL_TIMEOUT_US)
+
+static inline u32 apple_spmi_pack_cmd(u8 opc, u8 sid, u16 saddr, size_t len)
+{
+	return opc | sid << 8 | saddr << 16 | (len - 1) | (1 << 15);
+}
+
+/* Wait for Rx FIFO to have something */
+static int apple_spmi_wait_rx_not_empty(struct spmi_controller *ctrl)
+{
+	struct apple_spmi *spmi = spmi_controller_get_drvdata(ctrl);
+	int ret;
+	u32 status;
+
+	ret = poll_reg(spmi, SPMI_STATUS_REG, status, !(status & SPMI_RX_FIFO_EMPTY));
+	if (ret) {
+		dev_err(&ctrl->dev,
+			"failed to wait for RX FIFO not empty\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int spmi_read_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
+			 u16 saddr, u8 *buf, size_t len)
+{
+	struct apple_spmi *spmi = spmi_controller_get_drvdata(ctrl);
+	u32 spmi_cmd = apple_spmi_pack_cmd(opc, sid, saddr, len);
+	u32 rsp;
+	size_t len_read = 0;
+	u8 i;
+	int ret;
+
+	writel(spmi_cmd, spmi->regs + SPMI_CMD_REG);
+
+	ret = apple_spmi_wait_rx_not_empty(ctrl);
+	if (ret)
+		return ret;
+
+	/* Discard SPMI reply status */
+	readl(spmi->regs + SPMI_RSP_REG);
+
+	/* Read SPMI data reply */
+	while (len_read < len) {
+		rsp = readl(spmi->regs + SPMI_RSP_REG);
+		i = 0;
+		while ((len_read < len) && (i < 4)) {
+			buf[len_read++] = ((0xff << (8 * i)) & rsp) >> (8 * i);
+			i += 1;
+		}
+	}
+
+	return 0;
+}
+
+static int spmi_write_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
+			  u16 saddr, const u8 *buf, size_t len)
+{
+	struct apple_spmi *spmi = spmi_controller_get_drvdata(ctrl);
+	u32 spmi_cmd = apple_spmi_pack_cmd(opc, sid, saddr, len);
+	size_t i = 0, j;
+	int ret;
+
+	writel(spmi_cmd, spmi->regs + SPMI_CMD_REG);
+
+	while (i < len) {
+		j = 0;
+		spmi_cmd = 0;
+		while ((j < 4) & (i < len))
+			spmi_cmd |= buf[i++] << (j++ * 8);
+
+		writel(spmi_cmd, spmi->regs + SPMI_CMD_REG);
+	}
+
+	ret = apple_spmi_wait_rx_not_empty(ctrl);
+	if (ret)
+		return ret;
+
+	/* Discard */
+	readl(spmi->regs + SPMI_RSP_REG);
+
+	return 0;
+}
+
+static int apple_spmi_probe(struct platform_device *pdev)
+{
+	struct apple_spmi *spmi;
+	struct spmi_controller *ctrl;
+	int ret;
+
+	ctrl = devm_spmi_controller_alloc(&pdev->dev, sizeof(*spmi));
+	if (IS_ERR(ctrl))
+		return -ENOMEM;
+
+	spmi = spmi_controller_get_drvdata(ctrl);
+
+	spmi->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(spmi->regs))
+		return PTR_ERR(spmi->regs);
+
+	ctrl->dev.of_node = pdev->dev.of_node;
+
+	ctrl->read_cmd = spmi_read_cmd;
+	ctrl->write_cmd = spmi_write_cmd;
+
+	ret = devm_spmi_controller_add(&pdev->dev, ctrl);
+	if (ret)
+		return dev_err_probe(&pdev->dev, ret,
+				     "spmi_controller_add failed\n");
+
+	return 0;
+}
+
+static const struct of_device_id apple_spmi_match_table[] = {
+	{ .compatible = "apple,spmi", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, apple_spmi_match_table);
+
+static struct platform_driver apple_spmi_driver = {
+	.probe		= apple_spmi_probe,
+	.driver		= {
+		.name	= "apple-spmi",
+		.of_match_table = apple_spmi_match_table,
+	},
+};
+module_platform_driver(apple_spmi_driver);
+
+MODULE_AUTHOR("Jean-Francois Bortolotti <jeff@borto.fr>");
+MODULE_DESCRIPTION("Apple SoC SPMI driver");
+MODULE_LICENSE("GPL");

-- 
2.48.1

[PATCH v3 3/3] arm64: dts: apple: Add SPMI controller nodes

[Sasha Finkelstein via B4 Relay]

From: Sasha Finkelstein <fnkl.kernel@gmail.com>

Add device tree entries for the SPMI controller

Reviewed-by: Nick Chan <towinchenmi@gmail.com>
Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
---
 arch/arm64/boot/dts/apple/t600x-die0.dtsi | 7 +++++++
 arch/arm64/boot/dts/apple/t8103.dtsi      | 8 ++++++++
 arch/arm64/boot/dts/apple/t8112.dtsi      | 7 +++++++
 3 files changed, 22 insertions(+)

diff --git a/arch/arm64/boot/dts/apple/t600x-die0.dtsi b/arch/arm64/boot/dts/apple/t600x-die0.dtsi
index b1c875e692c8fb9c0af46a23568a7b0cd720141b..64d4f301ca850ddb043bccc087e0b874fb96da9b 100644
--- a/arch/arm64/boot/dts/apple/t600x-die0.dtsi
+++ b/arch/arm64/boot/dts/apple/t600x-die0.dtsi
@@ -45,6 +45,13 @@ pinctrl_smc: pinctrl@290820000 {
 				<AIC_IRQ 0 749 IRQ_TYPE_LEVEL_HIGH>;
 	};
 
+	nub_spmi0: spmi@2920a1300 {
+		compatible = "apple,t6000-spmi", "apple,spmi";
+		reg = <0x2 0x920a1300 0x0 0x100>;
+		#address-cells = <2>;
+		#size-cells = <0>;
+	};
+
 	wdt: watchdog@2922b0000 {
 		compatible = "apple,t6000-wdt", "apple,wdt";
 		reg = <0x2 0x922b0000 0x0 0x4000>;
diff --git a/arch/arm64/boot/dts/apple/t8103.dtsi b/arch/arm64/boot/dts/apple/t8103.dtsi
index 9b0dad6b618444ac6b1c9735c50cccfc3965f947..0f03dc808cf7c6b7d71afc79dd29d368f957f979 100644
--- a/arch/arm64/boot/dts/apple/t8103.dtsi
+++ b/arch/arm64/boot/dts/apple/t8103.dtsi
@@ -11,6 +11,7 @@
 #include <dt-bindings/interrupt-controller/apple-aic.h>
 #include <dt-bindings/interrupt-controller/irq.h>
 #include <dt-bindings/pinctrl/apple.h>
+#include <dt-bindings/spmi/spmi.h>
 
 / {
 	compatible = "apple,t8103", "apple,arm-platform";
@@ -604,6 +605,13 @@ pcie_pins: pcie-pins {
 			};
 		};
 
+		nub_spmi: spmi@23d0d9300 {
+			compatible = "apple,t8103-spmi", "apple,spmi";
+			reg = <0x2 0x3d0d9300 0x0 0x100>;
+			#address-cells = <2>;
+			#size-cells = <0>;
+		};
+
 		pinctrl_nub: pinctrl@23d1f0000 {
 			compatible = "apple,t8103-pinctrl", "apple,pinctrl";
 			reg = <0x2 0x3d1f0000 0x0 0x4000>;
diff --git a/arch/arm64/boot/dts/apple/t8112.dtsi b/arch/arm64/boot/dts/apple/t8112.dtsi
index 1666e6ab250bc0be9b8318e3c8fc903ccd3f3760..fa4309bb92975c4edbc11c998496f125267f2353 100644
--- a/arch/arm64/boot/dts/apple/t8112.dtsi
+++ b/arch/arm64/boot/dts/apple/t8112.dtsi
@@ -679,6 +679,13 @@ wdt: watchdog@23d2b0000 {
 			interrupts = <AIC_IRQ 379 IRQ_TYPE_LEVEL_HIGH>;
 		};
 
+		nub_spmi: spmi@23d714000 {
+			compatible = "apple,t8112-spmi", "apple,spmi";
+			reg = <0x2 0x3d714000 0x0 0x100>;
+			#address-cells = <2>;
+			#size-cells = <0>;
+		};
+
 		pinctrl_smc: pinctrl@23e820000 {
 			compatible = "apple,t8112-pinctrl", "apple,pinctrl";
 			reg = <0x2 0x3e820000 0x0 0x4000>;

-- 
2.48.1

Re: [PATCH v3 2/3] spmi: add a spmi driver for Apple SoC

[Alyssa Rosenzweig]

Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>

Le Mon , Mar 10, 2025 at 11:07:59PM +0100, Sasha Finkelstein via B4 Relay a écrit :
> From: Jean-Francois Bortolotti <jeff@borto.fr>
> 
> The connected PMU contains several useful nvmem cells such as RTC offset,
> boot failure counters, reboot/shutdown selector, and a few others.
> In addition M3+ machines have their USB-PD controller connected via SPMI.
> 
> Signed-off-by: Jean-Francois Bortolotti <jeff@borto.fr>
> Reviewed-by: Sven Peter <sven@svenpeter.dev>
> Co-developed-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
> Signed-off-by: Sasha Finkelstein <fnkl.kernel@gmail.com>
> ---
>  MAINTAINERS                          |   1 +
>  drivers/spmi/Kconfig                 |   8 ++
>  drivers/spmi/Makefile                |   1 +
>  drivers/spmi/spmi-apple-controller.c | 168 +++++++++++++++++++++++++++++++++++
>  4 files changed, 178 insertions(+)
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 271ff8110df83c2d4fe7fbbfffc0a72259460bc5..9006695261d29fbc1e15659c2b43d7afeee0b656 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -2254,6 +2254,7 @@ F:	drivers/nvmem/apple-efuses.c
>  F:	drivers/pinctrl/pinctrl-apple-gpio.c
>  F:	drivers/pwm/pwm-apple.c
>  F:	drivers/soc/apple/*
> +F:	drivers/spmi/spmi-apple-controller.c
>  F:	drivers/watchdog/apple_wdt.c
>  F:	include/dt-bindings/interrupt-controller/apple-aic.h
>  F:	include/dt-bindings/pinctrl/apple.h
> diff --git a/drivers/spmi/Kconfig b/drivers/spmi/Kconfig
> index 73780204631463631cabcbad5bf83e8dbbee94ce..9005fa91d9f4e541403ccc7bf84e0592402ac41e 100644
> --- a/drivers/spmi/Kconfig
> +++ b/drivers/spmi/Kconfig
> @@ -11,6 +11,14 @@ menuconfig SPMI
>  
>  if SPMI
>  
> +config SPMI_APPLE
> +	tristate "Apple SoC SPMI Controller platform driver"
> +	depends on ARCH_APPLE || COMPILE_TEST
> +	help
> +	  If you say yes to this option, support will be included for the
> +	  SPMI controller present on many Apple SoCs, including the
> +	  t8103 (M1) and t600x (M1 Pro/Max).
> +
>  config SPMI_HISI3670
>  	tristate "Hisilicon 3670 SPMI Controller"
>  	select IRQ_DOMAIN_HIERARCHY
> diff --git a/drivers/spmi/Makefile b/drivers/spmi/Makefile
> index 7f152167bb05b2c24a0f9669f60278152898eebb..38ac635645ba65aa46cb5e8a50072ed9771e229b 100644
> --- a/drivers/spmi/Makefile
> +++ b/drivers/spmi/Makefile
> @@ -4,6 +4,7 @@
>  #
>  obj-$(CONFIG_SPMI)	+= spmi.o spmi-devres.o
>  
> +obj-$(CONFIG_SPMI_APPLE)	+= spmi-apple-controller.o
>  obj-$(CONFIG_SPMI_HISI3670)	+= hisi-spmi-controller.o
>  obj-$(CONFIG_SPMI_MSM_PMIC_ARB)	+= spmi-pmic-arb.o
>  obj-$(CONFIG_SPMI_MTK_PMIF)	+= spmi-mtk-pmif.o
> diff --git a/drivers/spmi/spmi-apple-controller.c b/drivers/spmi/spmi-apple-controller.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..697b3e8bb023566f17911fc222666d84f5e14c91
> --- /dev/null
> +++ b/drivers/spmi/spmi-apple-controller.c
> @@ -0,0 +1,168 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Apple SoC SPMI device driver
> + *
> + * Copyright The Asahi Linux Contributors
> + *
> + * Inspired by:
> + *		OpenBSD support Copyright (c) 2021 Mark Kettenis <kettenis@openbsd.org>
> + *		Correllium support Copyright (C) 2021 Corellium LLC
> + *		hisi-spmi-controller.c
> + *		spmi-pmic-arb.c Copyright (c) 2021, The Linux Foundation.
> + */
> +
> +#include <linux/io.h>
> +#include <linux/iopoll.h>
> +#include <linux/module.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/platform_device.h>
> +#include <linux/spmi.h>
> +
> +/* SPMI Controller Registers */
> +#define SPMI_STATUS_REG 0
> +#define SPMI_CMD_REG 0x4
> +#define SPMI_RSP_REG 0x8
> +
> +#define SPMI_RX_FIFO_EMPTY BIT(24)
> +
> +#define REG_POLL_INTERVAL_US 10000
> +#define REG_POLL_TIMEOUT_US (REG_POLL_INTERVAL_US * 5)
> +
> +struct apple_spmi {
> +	void __iomem *regs;
> +};
> +
> +#define poll_reg(spmi, reg, val, cond) \
> +	readl_poll_timeout((spmi)->regs + (reg), (val), (cond), \
> +			   REG_POLL_INTERVAL_US, REG_POLL_TIMEOUT_US)
> +
> +static inline u32 apple_spmi_pack_cmd(u8 opc, u8 sid, u16 saddr, size_t len)
> +{
> +	return opc | sid << 8 | saddr << 16 | (len - 1) | (1 << 15);
> +}
> +
> +/* Wait for Rx FIFO to have something */
> +static int apple_spmi_wait_rx_not_empty(struct spmi_controller *ctrl)
> +{
> +	struct apple_spmi *spmi = spmi_controller_get_drvdata(ctrl);
> +	int ret;
> +	u32 status;
> +
> +	ret = poll_reg(spmi, SPMI_STATUS_REG, status, !(status & SPMI_RX_FIFO_EMPTY));
> +	if (ret) {
> +		dev_err(&ctrl->dev,
> +			"failed to wait for RX FIFO not empty\n");
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int spmi_read_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
> +			 u16 saddr, u8 *buf, size_t len)
> +{
> +	struct apple_spmi *spmi = spmi_controller_get_drvdata(ctrl);
> +	u32 spmi_cmd = apple_spmi_pack_cmd(opc, sid, saddr, len);
> +	u32 rsp;
> +	size_t len_read = 0;
> +	u8 i;
> +	int ret;
> +
> +	writel(spmi_cmd, spmi->regs + SPMI_CMD_REG);
> +
> +	ret = apple_spmi_wait_rx_not_empty(ctrl);
> +	if (ret)
> +		return ret;
> +
> +	/* Discard SPMI reply status */
> +	readl(spmi->regs + SPMI_RSP_REG);
> +
> +	/* Read SPMI data reply */
> +	while (len_read < len) {
> +		rsp = readl(spmi->regs + SPMI_RSP_REG);
> +		i = 0;
> +		while ((len_read < len) && (i < 4)) {
> +			buf[len_read++] = ((0xff << (8 * i)) & rsp) >> (8 * i);
> +			i += 1;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +static int spmi_write_cmd(struct spmi_controller *ctrl, u8 opc, u8 sid,
> +			  u16 saddr, const u8 *buf, size_t len)
> +{
> +	struct apple_spmi *spmi = spmi_controller_get_drvdata(ctrl);
> +	u32 spmi_cmd = apple_spmi_pack_cmd(opc, sid, saddr, len);
> +	size_t i = 0, j;
> +	int ret;
> +
> +	writel(spmi_cmd, spmi->regs + SPMI_CMD_REG);
> +
> +	while (i < len) {
> +		j = 0;
> +		spmi_cmd = 0;
> +		while ((j < 4) & (i < len))
> +			spmi_cmd |= buf[i++] << (j++ * 8);
> +
> +		writel(spmi_cmd, spmi->regs + SPMI_CMD_REG);
> +	}
> +
> +	ret = apple_spmi_wait_rx_not_empty(ctrl);
> +	if (ret)
> +		return ret;
> +
> +	/* Discard */
> +	readl(spmi->regs + SPMI_RSP_REG);
> +
> +	return 0;
> +}
> +
> +static int apple_spmi_probe(struct platform_device *pdev)
> +{
> +	struct apple_spmi *spmi;
> +	struct spmi_controller *ctrl;
> +	int ret;
> +
> +	ctrl = devm_spmi_controller_alloc(&pdev->dev, sizeof(*spmi));
> +	if (IS_ERR(ctrl))
> +		return -ENOMEM;
> +
> +	spmi = spmi_controller_get_drvdata(ctrl);
> +
> +	spmi->regs = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(spmi->regs))
> +		return PTR_ERR(spmi->regs);
> +
> +	ctrl->dev.of_node = pdev->dev.of_node;
> +
> +	ctrl->read_cmd = spmi_read_cmd;
> +	ctrl->write_cmd = spmi_write_cmd;
> +
> +	ret = devm_spmi_controller_add(&pdev->dev, ctrl);
> +	if (ret)
> +		return dev_err_probe(&pdev->dev, ret,
> +				     "spmi_controller_add failed\n");
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id apple_spmi_match_table[] = {
> +	{ .compatible = "apple,spmi", },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, apple_spmi_match_table);
> +
> +static struct platform_driver apple_spmi_driver = {
> +	.probe		= apple_spmi_probe,
> +	.driver		= {
> +		.name	= "apple-spmi",
> +		.of_match_table = apple_spmi_match_table,
> +	},
> +};
> +module_platform_driver(apple_spmi_driver);
> +
> +MODULE_AUTHOR("Jean-Francois Bortolotti <jeff@borto.fr>");
> +MODULE_DESCRIPTION("Apple SoC SPMI driver");
> +MODULE_LICENSE("GPL");
> 
> -- 
> 2.48.1
> 
>