Signed-off-by: David Mosberger <davidm@xxxxxxxxxx> --- .../devicetree/bindings/nvmem/atmel-secumod.txt | 46 ++++++++ drivers/nvmem/atmel-secumod.c | 125 +++++++++++++++++++++ 2 files changed, 171 insertions(+) create mode 100644 Documentation/devicetree/bindings/nvmem/atmel-secumod.txt create mode 100644 drivers/nvmem/atmel-secumod.c diff --git a/Documentation/devicetree/bindings/nvmem/atmel-secumod.txt b/Documentation/devicetree/bindings/nvmem/atmel-secumod.txt new file mode 100644 index 0000000..85db709 --- /dev/null +++ b/Documentation/devicetree/bindings/nvmem/atmel-secumod.txt @@ -0,0 +1,46 @@ += Atmel Secumod device tree bindings = + +This binding is intended to represent Atmel's Secumod which is found +in SAMA5D2 and perhaps others. + +Required properties: +- compatible: should be "atmel,sama5d2-secumod" +- reg: Should contain registers location and length of the RAM, followed + by register location and length of the Secumod controller. + += Data cells = +Are child nodes of secumod, bindings of which as described in +bindings/nvmem/nvmem.txt + +Example: + + secumod@fc040000 { + compatible = "atmel,sama5d2-secumod"; + reg = <0xf8044000 0x1420 + 0xfc040000 0x4000>; + status = "okay"; + + #address-cells = <1>; + #size-cells = <1>; + + secram_auto_erasable@0000 { + reg = <0x0000 0x1000>; + }; + secram@1000 { + reg = <0x1000 0x400>; + }; + ram@1400 { + reg = <0x1400 0x20>; + }; + }; + += Data consumers = +Are device nodes which consume nvmem data cells. + +For example: + + ram { + ... + nvmem-cells = <&ram>; + nvmem-cell-names = "RAM"; + }; diff --git a/drivers/nvmem/atmel-secumod.c b/drivers/nvmem/atmel-secumod.c new file mode 100644 index 0000000..fda83c9 --- /dev/null +++ b/drivers/nvmem/atmel-secumod.c @@ -0,0 +1,125 @@ +/* + * Driver for SAMA5D2 secure module (SECUMOD). + * + * Copyright (C) 2016 eGauge Systems LLC + * + * David Mosberger <davidm@xxxxxxxxxx> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/nvmem-provider.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +static struct regmap_config secumod_regmap_config = { + .reg_bits = 32, + .val_bits = 32, + .reg_stride = 4 +}; + +static struct nvmem_config econfig = { + .name = "secumod", + .owner = THIS_MODULE, +}; + +/* + * Security-module register definitions: + */ +#define SECUMOD_RAMRDY 0x0014 + +/* + * Since the secure module may need to automatically erase some of the + * RAM, it may take a while for it to be ready. As far as I know, + * it's not documented how long this might take in the worst-case. + */ +static void +secumod_wait_ready (void *regs) +{ + unsigned long start, stop; + + start = jiffies; + while (!(readl(regs + SECUMOD_RAMRDY) & 1)) + msleep_interruptible(1); + stop = jiffies; + if (stop != start) + pr_info("nvmem-atmel-secumod: it took %u msec for SECUMOD " + "to become ready...\n", jiffies_to_msecs(stop - start)); + else + pr_info("nvmem-atmel-secumod: ready\n"); +} + +static int secumod_remove(struct platform_device *pdev) +{ + struct nvmem_device *nvmem = platform_get_drvdata(pdev); + + return nvmem_unregister(nvmem); +} + +static int secumod_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct resource *res; + struct nvmem_device *nvmem; + struct regmap *regmap; + void __iomem *base; + + /* + * Map controller address temporarily so we can ensure that + * the hardware is ready: + */ + res = platform_get_resource(pdev, IORESOURCE_MEM, 1); + base = devm_ioremap_resource(dev, res); + if (IS_ERR(base)) + return PTR_ERR(base); + + secumod_wait_ready(base); + devm_iounmap(dev, base); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + base = devm_ioremap_resource(dev, res); + + if (IS_ERR(base)) + return PTR_ERR(base); + + secumod_regmap_config.max_register = resource_size(res) - 1; + + regmap = devm_regmap_init_mmio(dev, base, &secumod_regmap_config); + if (IS_ERR(regmap)) { + dev_err(dev, "%s: regmap init failed\n", __func__); + return PTR_ERR(regmap); + } + econfig.dev = dev; + nvmem = nvmem_register(&econfig); + if (IS_ERR(nvmem)) + return PTR_ERR(nvmem); + + platform_set_drvdata(pdev, nvmem); + + return 0; +} + +static const struct of_device_id secumod_of_match[] = { + { .compatible = "atmel,sama5d2-secumod",}, + {/* sentinel */}, +}; +MODULE_DEVICE_TABLE(of, secumod_of_match); + +static struct platform_driver secumod_driver = { + .probe = secumod_probe, + .remove = secumod_remove, + .driver = { + .name = "atmel,sama5d2-secumod", + .of_match_table = secumod_of_match, + }, +}; +module_platform_driver(secumod_driver); +MODULE_AUTHOR("David Mosberger <davidm@xxxxxxxxxx>"); +MODULE_DESCRIPTION("Atmel Secumod driver"); +MODULE_LICENSE("GPL v2"); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html