diff mbox series

[2/2] nvmem: Add Apple eFuse driver

Message ID 20220227115743.69059-2-sven@svenpeter.dev (mailing list archive)
State New, archived
Headers show
Series [1/2] dt-bindings: nvmem: Add apple,efuses | expand

Commit Message

Sven Peter Feb. 27, 2022, 11:57 a.m. UTC 
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>
---
 MAINTAINERS                  |  1 +
 drivers/nvmem/Kconfig        | 12 +++++++
 drivers/nvmem/Makefile       |  2 ++
 drivers/nvmem/apple-efuses.c | 67 ++++++++++++++++++++++++++++++++++++
 4 files changed, 82 insertions(+)
 create mode 100644 drivers/nvmem/apple-efuses.c

Comments

kernel test robot March 3, 2022, 2:16 p.m. UTC | #1 
Hi Sven,

I love your patch! Perhaps something to improve:

[auto build test WARNING on soc/for-next]
[also build test WARNING on linus/master v5.17-rc6]
[cannot apply to robh/for-next next-20220303]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Sven-Peter/dt-bindings-nvmem-Add-apple-efuses/20220227-195847
base:   https://git.kernel.org/pub/scm/linux/kernel/git/soc/soc.git for-next
config: ia64-randconfig-s031-20220302 (https://download.01.org/0day-ci/archive/20220303/202203032219.gDn8cX7m-lkp@intel.com/config)
compiler: ia64-linux-gcc (GCC) 11.2.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # apt-get install sparse
        # sparse version: v0.6.4-dirty
        # https://github.com/0day-ci/linux/commit/e47f957c24fcbc9f99a972b1b7c802eec04ed40a
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Sven-Peter/dt-bindings-nvmem-Add-apple-efuses/20220227-195847
        git checkout e47f957c24fcbc9f99a972b1b7c802eec04ed40a
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=ia64 SHELL=/bin/bash drivers/nvmem/

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>


sparse warnings: (new ones prefixed by >>)
>> drivers/nvmem/apple-efuses.c:17:31: sparse: sparse: incorrect type in initializer (different address spaces) @@     expected void [noderef] __iomem *fuses @@     got void *context @@
   drivers/nvmem/apple-efuses.c:17:31: sparse:     expected void [noderef] __iomem *fuses
   drivers/nvmem/apple-efuses.c:17:31: sparse:     got void *context
>> drivers/nvmem/apple-efuses.c:42:21: sparse: sparse: incorrect type in assignment (different address spaces) @@     expected void *priv @@     got void [noderef] __iomem * @@
   drivers/nvmem/apple-efuses.c:42:21: sparse:     expected void *priv
   drivers/nvmem/apple-efuses.c:42:21: sparse:     got void [noderef] __iomem *
   drivers/nvmem/apple-efuses.c: note: in included file (through arch/ia64/include/asm/io.h, include/linux/io.h):
   include/asm-generic/io.h:267:16: sparse: sparse: cast to restricted __le32

vim +17 drivers/nvmem/apple-efuses.c

    13	
    14	static int apple_efuses_read(void *context, unsigned int offset, void *val,
    15				     size_t bytes)
    16	{
  > 17		void __iomem *fuses = context;
    18		u32 *dst = val;
    19	
    20		while (bytes >= sizeof(u32)) {
    21			*dst++ = readl_relaxed(fuses + offset);
    22			bytes -= sizeof(u32);
    23			offset += sizeof(u32);
    24		}
    25	
    26		return 0;
    27	}
    28	
    29	static int apple_efuses_probe(struct platform_device *pdev)
    30	{
    31		struct resource *res;
    32		struct nvmem_config config = {
    33			.dev = &pdev->dev,
    34			.read_only = true,
    35			.reg_read = apple_efuses_read,
    36			.stride = sizeof(u32),
    37			.word_size = sizeof(u32),
    38			.name = "apple_efuses_nvmem",
    39			.id = NVMEM_DEVID_AUTO,
    40		};
    41	
  > 42		config.priv = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
    43		if (IS_ERR(config.priv))
    44			return PTR_ERR(config.priv);
    45	
    46		config.size = resource_size(res);
    47	
    48		return PTR_ERR_OR_ZERO(devm_nvmem_register(config.dev, &config));
    49	}
    50	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 1bc57af09c80..031198aec108 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1781,6 +1781,7 @@  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
diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index da414617a54d..ef6a13c8a4d6 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -300,4 +300,16 @@  config NVMEM_BRCM_NVRAM
 	  This driver provides support for Broadcom's NVRAM that can be accessed
 	  using I/O mapping.
 
+config NVMEM_APPLE_EFUSES
+	tristate "Apple eFuse support"
+	depends on ARCH_APPLE || COMPILE_TEST
+	default ARCH_APPLE
+	help
+	  Say y here to enabled 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 dcbbde35b6a8..1a8e54691d3e 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -61,3 +61,5 @@  obj-$(CONFIG_NVMEM_RMEM) 	+= nvmem-rmem.o
 nvmem-rmem-y			:= rmem.o
 obj-$(CONFIG_NVMEM_BRCM_NVRAM)	+= nvmem_brcm_nvram.o
 nvmem_brcm_nvram-y		:= brcm_nvram.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..925fc0033b83
--- /dev/null
+++ b/drivers/nvmem/apple-efuses.c
@@ -0,0 +1,67 @@ 
+// 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>
+
+static int apple_efuses_read(void *context, unsigned int offset, void *val,
+			     size_t bytes)
+{
+	void __iomem *fuses = context;
+	u32 *dst = val;
+
+	while (bytes >= sizeof(u32)) {
+		*dst++ = readl_relaxed(fuses + offset);
+		bytes -= sizeof(u32);
+		offset += sizeof(u32);
+	}
+
+	return 0;
+}
+
+static int apple_efuses_probe(struct platform_device *pdev)
+{
+	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,
+	};
+
+	config.priv = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(config.priv))
+		return PTR_ERR(config.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", },
+	{}
+};
+
+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");