[PATCH v4 1/3] MAINTAINERS: Add apple efuses nvmem files to ARM/APPLE MACHINE

[PATCH v4 1/3] MAINTAINERS: Add apple efuses nvmem files to ARM/APPLE MACHINE

[Sven Peter]

Signed-off-by: Sven Peter <sven@svenpeter.dev>
---
v4:
  - new commit to split off MAINTAINER changes requested by Srinivas Kandagatla

 MAINTAINERS | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index fd768d43e048..1bf57fd937b5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1837,6 +1837,7 @@ F:	Documentation/devicetree/bindings/clock/apple,nco.yaml
 F:	Documentation/devicetree/bindings/i2c/apple,i2c.yaml
 F:	Documentation/devicetree/bindings/interrupt-controller/apple,*
 F:	Documentation/devicetree/bindings/mailbox/apple,mailbox.yaml
+F:	Documentation/devicetree/bindings/nvmem/apple,efuses.yaml
 F:	Documentation/devicetree/bindings/pci/apple,pcie.yaml
 F:	Documentation/devicetree/bindings/pinctrl/apple,pinctrl.yaml
 F:	Documentation/devicetree/bindings/power/apple*
@@ -1847,6 +1848,7 @@ F:	drivers/i2c/busses/i2c-pasemi-core.c
 F:	drivers/i2c/busses/i2c-pasemi-platform.c
 F:	drivers/irqchip/irq-apple-aic.c
 F:	drivers/mailbox/apple-mailbox.c
+F:	drivers/nvmem/apple-efuses.c
 F:	drivers/pinctrl/pinctrl-apple-gpio.c
 F:	drivers/soc/apple/*
 F:	drivers/watchdog/apple_wdt.c
-- 
2.25.1

[PATCH v4 2/3] dt-bindings: nvmem: Add apple,efuses

[Sven Peter]

Apple SoCs come with eFuses used to store factory-programmed data
such as calibration settings for the PCIe and Type-C PHY.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sven Peter <sven@svenpeter.dev>
---
v3 -> v4:
  - added rob's ack
  - rebased on 5.18-rc1 and split off MAINTAINER changes as requested
    by Srinivas Kandagatla
v2 -> v3:
  - added r-b tag
v1 -> v2:
  - fixed indentation issue pointed out by Krzysztof Kozlowski

 .../bindings/nvmem/apple,efuses.yaml          | 50 +++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/nvmem/apple,efuses.yaml

diff --git a/Documentation/devicetree/bindings/nvmem/apple,efuses.yaml b/Documentation/devicetree/bindings/nvmem/apple,efuses.yaml
new file mode 100644
index 000000000000..5ec8f2bdb3a5
--- /dev/null
+++ b/Documentation/devicetree/bindings/nvmem/apple,efuses.yaml
@@ -0,0 +1,50 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/nvmem/apple,efuses.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Apple SoC eFuse-based NVMEM
+
+description: |
+  Apple SoCs such as the M1 contain factory-programmed eFuses used to e.g. store
+  calibration data for the PCIe and the Type-C PHY or unique chip identifiers
+  such as the ECID.
+
+maintainers:
+  - Sven Peter <sven@svenpeter.dev>
+
+allOf:
+  - $ref: "nvmem.yaml#"
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - apple,t8103-efuses
+          - apple,t6000-efuses
+      - const: apple,efuses
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    efuse@3d2bc000 {
+        compatible = "apple,t8103-efuses", "apple,efuses";
+        reg = <0x3d2bc000 0x1000>;
+        #address-cells = <1>;
+        #size-cells = <1>;
+
+        ecid: efuse@500 {
+            reg = <0x500 0x8>;
+        };
+    };
+
+...
-- 
2.25.1

[PATCH v4 3/3] nvmem: Add Apple eFuse driver

[Sven Peter]

Apple SoCs contain eFuses used to store factory-programmed data such
as calibration values for the PCIe or the Type-C PHY. They are organized
as 32bit values exposed as MMIO.

Signed-off-by: Sven Peter <sven@svenpeter.dev>
---
v3 -> v4:
  - rebased on 5.18-rc1 and split off MAINTAINER changes as requested
    by Srinivas Kandagatla
v2 -> v3:
  - removed .owner = THIS_MODULE again since it's already done by the
    core as pointed out by Krzysztof Kozlowski
v1 -> v2:
  - fixed sparse warning about __iomem by introducing
    struct apple_efuses_priv as done in other nvmem drivers
  - make sure the driver actually works as a module by
    setting .owner to THIS_MODULE and adding MODULE_DEVICE_TABLE
    pointed out by Joey Gouly

 drivers/nvmem/Kconfig        | 12 ++++++
 drivers/nvmem/Makefile       |  2 +
 drivers/nvmem/apple-efuses.c | 80 ++++++++++++++++++++++++++++++++++++
 3 files changed, 94 insertions(+)
 create mode 100644 drivers/nvmem/apple-efuses.c

diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 555aa77a574d..6283e09cc1e9 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -324,4 +324,16 @@ config NVMEM_SUNPLUS_OCOTP
 	  This driver can also be built as a module. If so, the module
 	  will be called nvmem-sunplus-ocotp.
 
+config NVMEM_APPLE_EFUSES
+	tristate "Apple eFuse support"
+	depends on ARCH_APPLE || COMPILE_TEST
+	default ARCH_APPLE
+	help
+	  Say y here to enable support for reading eFuses on Apple SoCs
+	  such as the M1. These are e.g. used to store factory programmed
+	  calibration data required for the PCIe or the USB-C PHY.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called nvmem-apple-efuses.
+
 endif
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index 891958e29d25..00e136a0a123 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -65,3 +65,5 @@ obj-$(CONFIG_NVMEM_LAYERSCAPE_SFP)	+= nvmem-layerscape-sfp.o
 nvmem-layerscape-sfp-y		:= layerscape-sfp.o
 obj-$(CONFIG_NVMEM_SUNPLUS_OCOTP)	+= nvmem_sunplus_ocotp.o
 nvmem_sunplus_ocotp-y		:= sunplus-ocotp.o
+obj-$(CONFIG_NVMEM_APPLE_EFUSES)	+= nvmem-apple-efuses.o
+nvmem-apple-efuses-y 		:= apple-efuses.o
diff --git a/drivers/nvmem/apple-efuses.c b/drivers/nvmem/apple-efuses.c
new file mode 100644
index 000000000000..9b7c87102104
--- /dev/null
+++ b/drivers/nvmem/apple-efuses.c
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Apple SoC eFuse driver
+ *
+ * Copyright (C) The Asahi Linux Contributors
+ */
+
+#include <linux/io.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/nvmem-provider.h>
+#include <linux/platform_device.h>
+
+struct apple_efuses_priv {
+	void __iomem *fuses;
+};
+
+static int apple_efuses_read(void *context, unsigned int offset, void *val,
+			     size_t bytes)
+{
+	struct apple_efuses_priv *priv = context;
+	u32 *dst = val;
+
+	while (bytes >= sizeof(u32)) {
+		*dst++ = readl_relaxed(priv->fuses + offset);
+		bytes -= sizeof(u32);
+		offset += sizeof(u32);
+	}
+
+	return 0;
+}
+
+static int apple_efuses_probe(struct platform_device *pdev)
+{
+	struct apple_efuses_priv *priv;
+	struct resource *res;
+	struct nvmem_config config = {
+		.dev = &pdev->dev,
+		.read_only = true,
+		.reg_read = apple_efuses_read,
+		.stride = sizeof(u32),
+		.word_size = sizeof(u32),
+		.name = "apple_efuses_nvmem",
+		.id = NVMEM_DEVID_AUTO,
+		.root_only = true,
+	};
+
+	priv = devm_kzalloc(config.dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->fuses = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(priv->fuses))
+		return PTR_ERR(priv->fuses);
+
+	config.priv = priv;
+	config.size = resource_size(res);
+
+	return PTR_ERR_OR_ZERO(devm_nvmem_register(config.dev, &config));
+}
+
+static const struct of_device_id apple_efuses_of_match[] = {
+	{ .compatible = "apple,efuses", },
+	{}
+};
+
+MODULE_DEVICE_TABLE(of, apple_efuses_of_match);
+
+static struct platform_driver apple_efuses_driver = {
+	.driver = {
+		.name = "apple_efuses",
+		.of_match_table = apple_efuses_of_match,
+	},
+	.probe = apple_efuses_probe,
+};
+
+module_platform_driver(apple_efuses_driver);
+
+MODULE_AUTHOR("Sven Peter <sven@svenpeter.dev>");
+MODULE_LICENSE("GPL");
-- 
2.25.1

Re: [PATCH v4 3/3] nvmem: Add Apple eFuse driver

[Srinivas Kandagatla]

On 10/04/2022 14:54, Sven Peter wrote:
> Apple SoCs contain eFuses used to store factory-programmed data such
> as calibration values for the PCIe or the Type-C PHY. They are organized
> as 32bit values exposed as MMIO.
> 
> Signed-off-by: Sven Peter <sven@svenpeter.dev>


Applied all 3,

thanks,
--srini


> ---
> v3 -> v4:
>    - rebased on 5.18-rc1 and split off MAINTAINER changes as requested
>      by Srinivas Kandagatla
> v2 -> v3:
>    - removed .owner = THIS_MODULE again since it's already done by the
>      core as pointed out by Krzysztof Kozlowski
> v1 -> v2:
>    - fixed sparse warning about __iomem by introducing
>      struct apple_efuses_priv as done in other nvmem drivers
>    - make sure the driver actually works as a module by
>      setting .owner to THIS_MODULE and adding MODULE_DEVICE_TABLE
>      pointed out by Joey Gouly
> 
>   drivers/nvmem/Kconfig        | 12 ++++++
>   drivers/nvmem/Makefile       |  2 +
>   drivers/nvmem/apple-efuses.c | 80 ++++++++++++++++++++++++++++++++++++
>   3 files changed, 94 insertions(+)
>   create mode 100644 drivers/nvmem/apple-efuses.c
> 
> diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
> index 555aa77a574d..6283e09cc1e9 100644
> --- a/drivers/nvmem/Kconfig
> +++ b/drivers/nvmem/Kconfig
> @@ -324,4 +324,16 @@ config NVMEM_SUNPLUS_OCOTP
>   	  This driver can also be built as a module. If so, the module
>   	  will be called nvmem-sunplus-ocotp.
>   
> +config NVMEM_APPLE_EFUSES
> +	tristate "Apple eFuse support"
> +	depends on ARCH_APPLE || COMPILE_TEST
> +	default ARCH_APPLE
> +	help
> +	  Say y here to enable support for reading eFuses on Apple SoCs
> +	  such as the M1. These are e.g. used to store factory programmed
> +	  calibration data required for the PCIe or the USB-C PHY.
> +
> +	  This driver can also be built as a module. If so, the module will
> +	  be called nvmem-apple-efuses.
> +
>   endif
> diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
> index 891958e29d25..00e136a0a123 100644
> --- a/drivers/nvmem/Makefile
> +++ b/drivers/nvmem/Makefile
> @@ -65,3 +65,5 @@ obj-$(CONFIG_NVMEM_LAYERSCAPE_SFP)	+= nvmem-layerscape-sfp.o
>   nvmem-layerscape-sfp-y		:= layerscape-sfp.o
>   obj-$(CONFIG_NVMEM_SUNPLUS_OCOTP)	+= nvmem_sunplus_ocotp.o
>   nvmem_sunplus_ocotp-y		:= sunplus-ocotp.o
> +obj-$(CONFIG_NVMEM_APPLE_EFUSES)	+= nvmem-apple-efuses.o
> +nvmem-apple-efuses-y 		:= apple-efuses.o
> diff --git a/drivers/nvmem/apple-efuses.c b/drivers/nvmem/apple-efuses.c
> new file mode 100644
> index 000000000000..9b7c87102104
> --- /dev/null
> +++ b/drivers/nvmem/apple-efuses.c
> @@ -0,0 +1,80 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Apple SoC eFuse driver
> + *
> + * Copyright (C) The Asahi Linux Contributors
> + */
> +
> +#include <linux/io.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/nvmem-provider.h>
> +#include <linux/platform_device.h>
> +
> +struct apple_efuses_priv {
> +	void __iomem *fuses;
> +};
> +
> +static int apple_efuses_read(void *context, unsigned int offset, void *val,
> +			     size_t bytes)
> +{
> +	struct apple_efuses_priv *priv = context;
> +	u32 *dst = val;
> +
> +	while (bytes >= sizeof(u32)) {
> +		*dst++ = readl_relaxed(priv->fuses + offset);
> +		bytes -= sizeof(u32);
> +		offset += sizeof(u32);
> +	}
> +
> +	return 0;
> +}
> +
> +static int apple_efuses_probe(struct platform_device *pdev)
> +{
> +	struct apple_efuses_priv *priv;
> +	struct resource *res;
> +	struct nvmem_config config = {
> +		.dev = &pdev->dev,
> +		.read_only = true,
> +		.reg_read = apple_efuses_read,
> +		.stride = sizeof(u32),
> +		.word_size = sizeof(u32),
> +		.name = "apple_efuses_nvmem",
> +		.id = NVMEM_DEVID_AUTO,
> +		.root_only = true,
> +	};
> +
> +	priv = devm_kzalloc(config.dev, sizeof(*priv), GFP_KERNEL);
> +	if (!priv)
> +		return -ENOMEM;
> +
> +	priv->fuses = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
> +	if (IS_ERR(priv->fuses))
> +		return PTR_ERR(priv->fuses);
> +
> +	config.priv = priv;
> +	config.size = resource_size(res);
> +
> +	return PTR_ERR_OR_ZERO(devm_nvmem_register(config.dev, &config));
> +}
> +
> +static const struct of_device_id apple_efuses_of_match[] = {
> +	{ .compatible = "apple,efuses", },
> +	{}
> +};
> +
> +MODULE_DEVICE_TABLE(of, apple_efuses_of_match);
> +
> +static struct platform_driver apple_efuses_driver = {
> +	.driver = {
> +		.name = "apple_efuses",
> +		.of_match_table = apple_efuses_of_match,
> +	},
> +	.probe = apple_efuses_probe,
> +};
> +
> +module_platform_driver(apple_efuses_driver);
> +
> +MODULE_AUTHOR("Sven Peter <sven@svenpeter.dev>");
> +MODULE_LICENSE("GPL");