From: André Draszik Date: Fri, 9 May 2025 13:22:41 +0000 (+0100) Subject: nvmem: max77759: Add Maxim MAX77759 NVMEM driver X-Git-Tag: v6.16-rc1~63^2~55^3 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8824dc7f947ac5916cf166bb8289af48c2b50bc7;p=thirdparty%2Fkernel%2Fstable.git nvmem: max77759: Add Maxim MAX77759 NVMEM driver The Maxim MAX77759 is a companion PMIC for USB Type-C applications and includes Battery Charger, Fuel Gauge, temperature sensors, USB Type-C Port Controller (TCPC), NVMEM, and a GPIO expander. This driver exposes the non volatile memory using the platform device registered by the core MFD driver. Signed-off-by: André Draszik Acked-by: Srinivas Kandagatla Acked-by: Peter Griffin Link: https://lore.kernel.org/r/20250509-max77759-mfd-v10-3-962ac15ee3ef@linaro.org Signed-off-by: Lee Jones --- diff --git a/MAINTAINERS b/MAINTAINERS index 5c5ff0ea40302..1fe7d9e8e44d4 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -14582,6 +14582,7 @@ S: Maintained F: Documentation/devicetree/bindings/*/maxim,max77759*.yaml F: drivers/gpio/gpio-max77759.c F: drivers/mfd/max77759.c +F: drivers/nvmem/max77759-nvmem.c F: include/linux/mfd/max77759.h MAXIM MAX77802 PMIC REGULATOR DEVICE DRIVER diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig index 8671b7c974b93..3de07ef524906 100644 --- a/drivers/nvmem/Kconfig +++ b/drivers/nvmem/Kconfig @@ -154,6 +154,18 @@ config NVMEM_LPC18XX_OTP To compile this driver as a module, choose M here: the module will be called nvmem_lpc18xx_otp. +config NVMEM_MAX77759 + tristate "Maxim Integrated MAX77759 NVMEM Support" + depends on MFD_MAX77759 + default MFD_MAX77759 + help + Say Y here to include support for the user-accessible storage found + in Maxim Integrated MAX77759 PMICs. This IC provides space for 30 + bytes of storage. + + This driver can also be built as a module. If so, the module + will be called nvmem-max77759. + config NVMEM_MESON_EFUSE tristate "Amlogic Meson GX eFuse Support" depends on (ARCH_MESON || COMPILE_TEST) && MESON_SM diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile index 5b77bbb6488bf..a9d03cfbbd27e 100644 --- a/drivers/nvmem/Makefile +++ b/drivers/nvmem/Makefile @@ -34,6 +34,8 @@ obj-$(CONFIG_NVMEM_LPC18XX_EEPROM) += nvmem_lpc18xx_eeprom.o nvmem_lpc18xx_eeprom-y := lpc18xx_eeprom.o obj-$(CONFIG_NVMEM_LPC18XX_OTP) += nvmem_lpc18xx_otp.o nvmem_lpc18xx_otp-y := lpc18xx_otp.o +obj-$(CONFIG_NVMEM_MAX77759) += nvmem-max77759.o +nvmem-max77759-y := max77759-nvmem.o obj-$(CONFIG_NVMEM_MESON_EFUSE) += nvmem_meson_efuse.o nvmem_meson_efuse-y := meson-efuse.o obj-$(CONFIG_NVMEM_MESON_MX_EFUSE) += nvmem_meson_mx_efuse.o diff --git a/drivers/nvmem/max77759-nvmem.c b/drivers/nvmem/max77759-nvmem.c new file mode 100644 index 0000000000000..c9961ad0e232e --- /dev/null +++ b/drivers/nvmem/max77759-nvmem.c @@ -0,0 +1,145 @@ +// SPDX-License-Identifier: GPL-2.0-only +// +// Copyright 2020 Google Inc +// Copyright 2025 Linaro Ltd. +// +// NVMEM driver for Maxim MAX77759 + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define MAX77759_NVMEM_OPCODE_HEADER_LEN 3 +/* + * NVMEM commands have a three byte header (which becomes part of the command), + * so we need to subtract that. + */ +#define MAX77759_NVMEM_SIZE (MAX77759_MAXQ_OPCODE_MAXLENGTH \ + - MAX77759_NVMEM_OPCODE_HEADER_LEN) + +struct max77759_nvmem { + struct device *dev; + struct max77759 *max77759; +}; + +static int max77759_nvmem_reg_read(void *priv, unsigned int offset, + void *val, size_t bytes) +{ + struct max77759_nvmem *nvmem = priv; + DEFINE_FLEX(struct max77759_maxq_command, cmd, cmd, length, + MAX77759_NVMEM_OPCODE_HEADER_LEN); + DEFINE_FLEX(struct max77759_maxq_response, rsp, rsp, length, + MAX77759_MAXQ_OPCODE_MAXLENGTH); + int ret; + + cmd->cmd[0] = MAX77759_MAXQ_OPCODE_USER_SPACE_READ; + cmd->cmd[1] = offset; + cmd->cmd[2] = bytes; + rsp->length = bytes + MAX77759_NVMEM_OPCODE_HEADER_LEN; + + ret = max77759_maxq_command(nvmem->max77759, cmd, rsp); + if (ret < 0) + return ret; + + if (memcmp(cmd->cmd, rsp->rsp, MAX77759_NVMEM_OPCODE_HEADER_LEN)) { + dev_warn(nvmem->dev, "protocol error (read)\n"); + return -EIO; + } + + memcpy(val, &rsp->rsp[MAX77759_NVMEM_OPCODE_HEADER_LEN], bytes); + + return 0; +} + +static int max77759_nvmem_reg_write(void *priv, unsigned int offset, + void *val, size_t bytes) +{ + struct max77759_nvmem *nvmem = priv; + DEFINE_FLEX(struct max77759_maxq_command, cmd, cmd, length, + MAX77759_MAXQ_OPCODE_MAXLENGTH); + DEFINE_FLEX(struct max77759_maxq_response, rsp, rsp, length, + MAX77759_MAXQ_OPCODE_MAXLENGTH); + int ret; + + cmd->cmd[0] = MAX77759_MAXQ_OPCODE_USER_SPACE_WRITE; + cmd->cmd[1] = offset; + cmd->cmd[2] = bytes; + memcpy(&cmd->cmd[MAX77759_NVMEM_OPCODE_HEADER_LEN], val, bytes); + cmd->length = bytes + MAX77759_NVMEM_OPCODE_HEADER_LEN; + rsp->length = cmd->length; + + ret = max77759_maxq_command(nvmem->max77759, cmd, rsp); + if (ret < 0) + return ret; + + if (memcmp(cmd->cmd, rsp->rsp, cmd->length)) { + dev_warn(nvmem->dev, "protocol error (write)\n"); + return -EIO; + } + + return 0; +} + +static int max77759_nvmem_probe(struct platform_device *pdev) +{ + struct nvmem_config config = { + .dev = &pdev->dev, + .name = dev_name(&pdev->dev), + .id = NVMEM_DEVID_NONE, + .type = NVMEM_TYPE_EEPROM, + .ignore_wp = true, + .size = MAX77759_NVMEM_SIZE, + .word_size = sizeof(u8), + .stride = sizeof(u8), + .reg_read = max77759_nvmem_reg_read, + .reg_write = max77759_nvmem_reg_write, + }; + struct max77759_nvmem *nvmem; + + nvmem = devm_kzalloc(&pdev->dev, sizeof(*nvmem), GFP_KERNEL); + if (!nvmem) + return -ENOMEM; + + nvmem->dev = &pdev->dev; + nvmem->max77759 = dev_get_drvdata(pdev->dev.parent); + + config.priv = nvmem; + + return PTR_ERR_OR_ZERO(devm_nvmem_register(config.dev, &config)); +} + +static const struct of_device_id max77759_nvmem_of_id[] = { + { .compatible = "maxim,max77759-nvmem", }, + { } +}; +MODULE_DEVICE_TABLE(of, max77759_nvmem_of_id); + +static const struct platform_device_id max77759_nvmem_platform_id[] = { + { "max77759-nvmem", }, + { } +}; +MODULE_DEVICE_TABLE(platform, max77759_nvmem_platform_id); + +static struct platform_driver max77759_nvmem_driver = { + .driver = { + .name = "max77759-nvmem", + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + .of_match_table = max77759_nvmem_of_id, + }, + .probe = max77759_nvmem_probe, + .id_table = max77759_nvmem_platform_id, +}; + +module_platform_driver(max77759_nvmem_driver); + +MODULE_AUTHOR("André Draszik "); +MODULE_DESCRIPTION("NVMEM driver for Maxim MAX77759"); +MODULE_LICENSE("GPL");