From: Arul Ramasamy <[email protected]> The Pistachio SoC from Imagination Technologies includes a generic eFuse Controller which exposes the status of 128 EFUSE bits to the external world.
Signed-off-by: Arul Ramasamy <[email protected]> Signed-off-by: Jude Abraham <[email protected]> Signed-off-by: Naidu Tellapati <[email protected]> --- drivers/soc/Kconfig | 1 + drivers/soc/Makefile | 1 + drivers/soc/img/Makefile | 1 + drivers/soc/img/fuse/Kconfig | 9 ++ drivers/soc/img/fuse/Makefile | 1 + drivers/soc/img/fuse/img-efuse.c | 192 +++++++++++++++++++++++++++++++++++++++ include/soc/img/img-efuse.h | 15 +++ 7 files changed, 220 insertions(+) create mode 100644 drivers/soc/img/Makefile create mode 100644 drivers/soc/img/fuse/Kconfig create mode 100644 drivers/soc/img/fuse/Makefile create mode 100644 drivers/soc/img/fuse/img-efuse.c create mode 100644 include/soc/img/img-efuse.h diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig index 76d6bd4..b699082 100644 --- a/drivers/soc/Kconfig +++ b/drivers/soc/Kconfig @@ -1,5 +1,6 @@ menu "SOC (System On Chip) specific Drivers" +source "drivers/soc/img/fuse/Kconfig" source "drivers/soc/qcom/Kconfig" source "drivers/soc/ti/Kconfig" source "drivers/soc/versatile/Kconfig" diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile index 063113d..eed9585 100644 --- a/drivers/soc/Makefile +++ b/drivers/soc/Makefile @@ -2,6 +2,7 @@ # Makefile for the Linux Kernel SOC specific device drivers. # +obj-$(CONFIG_SOC_IMG) += img/ obj-$(CONFIG_ARCH_QCOM) += qcom/ obj-$(CONFIG_ARCH_TEGRA) += tegra/ obj-$(CONFIG_SOC_TI) += ti/ diff --git a/drivers/soc/img/Makefile b/drivers/soc/img/Makefile new file mode 100644 index 0000000..f33a89f --- /dev/null +++ b/drivers/soc/img/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_SOC_IMG) += fuse/ diff --git a/drivers/soc/img/fuse/Kconfig b/drivers/soc/img/fuse/Kconfig new file mode 100644 index 0000000..7810ea3 --- /dev/null +++ b/drivers/soc/img/fuse/Kconfig @@ -0,0 +1,9 @@ +config IMG_EFUSE + tristate "Imagination Technologies Generic eFuse driver" + depends on HAS_IOMEM + help + Imagination Technologies Generic eFuse driver which exposes the status + of 128 EFUSE bits. + + To compile this driver as a module, choose M here: the module will + be called img-efuse. diff --git a/drivers/soc/img/fuse/Makefile b/drivers/soc/img/fuse/Makefile new file mode 100644 index 0000000..e873dc0 --- /dev/null +++ b/drivers/soc/img/fuse/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_IMG_EFUSE) += img-efuse.o diff --git a/drivers/soc/img/fuse/img-efuse.c b/drivers/soc/img/fuse/img-efuse.c new file mode 100644 index 0000000..de08b64 --- /dev/null +++ b/drivers/soc/img/fuse/img-efuse.c @@ -0,0 +1,192 @@ +/* + * Imagination Technologies Generic eFuse driver + * + * Copyright (c) 2014 Imagination Technologies Ltd. + * + * 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. + * + * Based on drivers/misc/eeprom/sunxi_sid.c Copyright (c) 2013 Oliver Schinagl + */ +#include <linux/clk.h> +#include <linux/compiler.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/export.h> +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/kobject.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/stat.h> +#include <linux/sysfs.h> +#include <linux/types.h> + +#include <soc/img/img-efuse.h> + +#define DRV_NAME "img-efuse" + +struct img_efuse { + void __iomem *base; + unsigned int size; + struct clk *osc_clk; + struct clk *sys_clk; +}; + +struct img_efuse *efuse_dev; + +static u8 img_efuse_read_byte(const unsigned int offset) +{ + u32 data; + + if (offset >= efuse_dev->size) + return 0; + + data = readl(efuse_dev->base + round_down(offset, 4)); + data >>= (offset % 4) * 8; + + return data; /* Only return the last byte */ +} + +int img_efuse_readl(unsigned int offset, u32 *value) +{ + if (!efuse_dev || IS_ERR(efuse_dev->base)) + return -ENODEV; + + if ((offset > (efuse_dev->size - 4)) || (offset % 4 != 0)) + return -EINVAL; + + *value = readl(efuse_dev->base + offset); + + return 0; +} +EXPORT_SYMBOL_GPL(img_efuse_readl); + +static ssize_t img_efuse_read(struct file *fd, struct kobject *kobj, + struct bin_attribute *attr, char *buf, + loff_t pos, size_t size) +{ + int i; + struct platform_device *pdev; + struct img_efuse *efuse; + + pdev = to_platform_device(kobj_to_dev(kobj)); + efuse = platform_get_drvdata(pdev); + + if (pos < 0 || pos >= efuse->size) + return 0; + + if (size > efuse->size - pos) + size = efuse->size - pos; + + for (i = 0; i < size; i++) + buf[i] = img_efuse_read_byte(pos + i); + + return i; +} + +static struct bin_attribute img_efuse_bin_attr = { + .attr = { .name = "efuse", .mode = S_IRUGO, }, + .read = img_efuse_read, +}; + +static int img_efuse_remove(struct platform_device *pdev) +{ + struct img_efuse *efuse; + + efuse = platform_get_drvdata(pdev); + + clk_disable_unprepare(efuse->osc_clk); + clk_disable_unprepare(efuse->sys_clk); + + device_remove_bin_file(&pdev->dev, &img_efuse_bin_attr); + + return 0; +} + +static const struct of_device_id img_efuse_of_match[] = { + { .compatible = "img,efuse", .data = (void *)16}, + {/* sentinel */}, +}; +MODULE_DEVICE_TABLE(of, img_efuse_of_match); + +static int img_efuse_probe(struct platform_device *pdev) +{ + int ret; + struct resource *res; + const struct of_device_id *of_dev_id; + + efuse_dev = devm_kzalloc(&pdev->dev, sizeof(struct img_efuse *), + GFP_KERNEL); + if (!efuse_dev) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + efuse_dev->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(efuse_dev->base)) + return PTR_ERR(efuse_dev->base); + + of_dev_id = of_match_device(img_efuse_of_match, &pdev->dev); + if (!of_dev_id) + return -ENODEV; + efuse_dev->size = (int)of_dev_id->data; + + efuse_dev->sys_clk = devm_clk_get(&pdev->dev, "sys"); + if (IS_ERR(efuse_dev->sys_clk)) { + dev_err(&pdev->dev, "failed to get system clock"); + return PTR_ERR(efuse_dev->sys_clk); + } + + efuse_dev->osc_clk = devm_clk_get(&pdev->dev, "osc"); + if (IS_ERR(efuse_dev->osc_clk)) { + dev_err(&pdev->dev, "failed to get oscillator clock"); + return PTR_ERR(efuse_dev->osc_clk); + } + + ret = clk_prepare_enable(efuse_dev->sys_clk); + if (ret < 0) { + dev_err(&pdev->dev, "could not enable system clock.\n"); + return ret; + } + + ret = clk_prepare_enable(efuse_dev->osc_clk); + if (ret < 0) { + dev_err(&pdev->dev, "could not enable oscillator clock.\n"); + goto disable_sysclk; + } + + platform_set_drvdata(pdev, efuse_dev); + + img_efuse_bin_attr.size = efuse_dev->size; + if (device_create_bin_file(&pdev->dev, &img_efuse_bin_attr)) { + ret = -ENODEV; + goto disable_oscclk; + } + + return 0; + +disable_oscclk: + clk_disable_unprepare(efuse_dev->osc_clk); +disable_sysclk: + clk_disable_unprepare(efuse_dev->sys_clk); + return ret; +} + +static struct platform_driver img_efuse_driver = { + .probe = img_efuse_probe, + .remove = img_efuse_remove, + .driver = { + .name = DRV_NAME, + .of_match_table = img_efuse_of_match, + }, +}; +module_platform_driver(img_efuse_driver); + +MODULE_AUTHOR("Arul Ramasamy<[email protected]>"); +MODULE_AUTHOR("Jude Abraham<[email protected]>"); +MODULE_DESCRIPTION("Imagination Technologies Generic eFuse driver"); +MODULE_LICENSE("GPL v2"); diff --git a/include/soc/img/img-efuse.h b/include/soc/img/img-efuse.h new file mode 100644 index 0000000..64bf4ad --- /dev/null +++ b/include/soc/img/img-efuse.h @@ -0,0 +1,15 @@ +/* + * Imagination Technologies Generic eFuse driver + * + * Copyright (C) 2014 Imagination Technologies Ltd. + * + * 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. + */ +#ifndef __IMG_EFUSE_H +#define __IMG_EFUSE_H + +int img_efuse_readl(unsigned int offset, u32 *value); + +#endif -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
