[PATCH 2/2] nvmem: add Rockchip eFuse support
Ahmad Fatoum
a.fatoum at pengutronix.de
Fri Jan 14 00:50:46 PST 2022
The driver allows read-only support to e.g. the Hardware UID, which
could in future be used to derive a MAC like U-Boot does.
Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
drivers/nvmem/Kconfig | 8 +
drivers/nvmem/Makefile | 1 +
drivers/nvmem/rockchip-efuse.c | 299 +++++++++++++++++++++++++++++++++
3 files changed, 308 insertions(+)
create mode 100644 drivers/nvmem/rockchip-efuse.c
diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 7b1ebe1d689d..ea1156918a34 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -84,4 +84,12 @@ config STARFIVE_OTP
This adds support for the StarFive OTP controller. Only reading
is currently supported.
+config ROCKCHIP_EFUSE
+ tristate "Rockchip eFuse Support"
+ depends on ARCH_ROCKCHIP || COMPILE_TEST
+ depends on OFDEVICE
+ help
+ This is a simple drive to dump specified values of Rockchip SoC
+ from eFuse, such as CPU ID.
+
endif
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index 586591961215..2261816c189c 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -25,3 +25,4 @@ obj-$(CONFIG_STM32_BSEC) += nvmem_bsec.o
nvmem_bsec-y := bsec.o
obj-$(CONFIG_STARFIVE_OTP) += starfive-otp.o
+obj-$(CONFIG_ROCKCHIP_EFUSE) += rockchip-efuse.o
diff --git a/drivers/nvmem/rockchip-efuse.c b/drivers/nvmem/rockchip-efuse.c
new file mode 100644
index 000000000000..24e7de0aa9ce
--- /dev/null
+++ b/drivers/nvmem/rockchip-efuse.c
@@ -0,0 +1,299 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Rockchip eFuse Driver
+ *
+ * Copyright (c) 2015 Rockchip Electronics Co. Ltd.
+ * Author: Caesar Wang <wxt at rock-chips.com>
+ */
+
+#include <common.h>
+#include <linux/clk.h>
+#include <linux/overflow.h>
+#include <clock.h>
+#include <driver.h>
+#include <io.h>
+#include <linux/nvmem-provider.h>
+#include <of.h>
+#include <init.h>
+
+#define clk_prepare_enable clk_enable
+#define clk_disable_unprepare clk_disable
+
+#define RK3288_A_SHIFT 6
+#define RK3288_A_MASK 0x3ff
+#define RK3288_PGENB BIT(3)
+#define RK3288_LOAD BIT(2)
+#define RK3288_STROBE BIT(1)
+#define RK3288_CSB BIT(0)
+
+#define RK3328_SECURE_SIZES 96
+#define RK3328_INT_STATUS 0x0018
+#define RK3328_DOUT 0x0020
+#define RK3328_AUTO_CTRL 0x0024
+#define RK3328_INT_FINISH BIT(0)
+#define RK3328_AUTO_ENB BIT(0)
+#define RK3328_AUTO_RD BIT(1)
+
+#define RK3399_A_SHIFT 16
+#define RK3399_A_MASK 0x3ff
+#define RK3399_NBYTES 4
+#define RK3399_STROBSFTSEL BIT(9)
+#define RK3399_RSB BIT(7)
+#define RK3399_PD BIT(5)
+#define RK3399_PGENB BIT(3)
+#define RK3399_LOAD BIT(2)
+#define RK3399_STROBE BIT(1)
+#define RK3399_CSB BIT(0)
+
+#define REG_EFUSE_CTRL 0x0000
+#define REG_EFUSE_DOUT 0x0004
+
+struct rockchip_efuse_chip {
+ struct device_d *dev;
+ void __iomem *base;
+ struct clk *clk;
+};
+
+static int rockchip_rk3288_efuse_read(void *context, unsigned int offset,
+ void *val, size_t bytes)
+{
+ struct rockchip_efuse_chip *efuse = context;
+ u8 *buf = val;
+ int ret;
+
+ ret = clk_prepare_enable(efuse->clk);
+ if (ret < 0) {
+ dev_err(efuse->dev, "failed to prepare/enable efuse clk\n");
+ return ret;
+ }
+
+ writel(RK3288_LOAD | RK3288_PGENB, efuse->base + REG_EFUSE_CTRL);
+ udelay(1);
+ while (bytes--) {
+ writel(readl(efuse->base + REG_EFUSE_CTRL) &
+ (~(RK3288_A_MASK << RK3288_A_SHIFT)),
+ efuse->base + REG_EFUSE_CTRL);
+ writel(readl(efuse->base + REG_EFUSE_CTRL) |
+ ((offset++ & RK3288_A_MASK) << RK3288_A_SHIFT),
+ efuse->base + REG_EFUSE_CTRL);
+ udelay(1);
+ writel(readl(efuse->base + REG_EFUSE_CTRL) |
+ RK3288_STROBE, efuse->base + REG_EFUSE_CTRL);
+ udelay(1);
+ *buf++ = readb(efuse->base + REG_EFUSE_DOUT);
+ writel(readl(efuse->base + REG_EFUSE_CTRL) &
+ (~RK3288_STROBE), efuse->base + REG_EFUSE_CTRL);
+ udelay(1);
+ }
+
+ /* Switch to standby mode */
+ writel(RK3288_PGENB | RK3288_CSB, efuse->base + REG_EFUSE_CTRL);
+
+ clk_disable_unprepare(efuse->clk);
+
+ return 0;
+}
+
+static int rockchip_rk3328_efuse_read(void *context, unsigned int offset,
+ void *val, size_t bytes)
+{
+ struct rockchip_efuse_chip *efuse = context;
+ unsigned int addr_start, addr_end, addr_offset, addr_len;
+ u32 out_value, status;
+ u8 *buf;
+ int ret, i = 0;
+
+ ret = clk_prepare_enable(efuse->clk);
+ if (ret < 0) {
+ dev_err(efuse->dev, "failed to prepare/enable efuse clk\n");
+ return ret;
+ }
+
+ /* 128 Byte efuse, 96 Byte for secure, 32 Byte for non-secure */
+ offset += RK3328_SECURE_SIZES;
+ addr_start = rounddown(offset, RK3399_NBYTES) / RK3399_NBYTES;
+ addr_end = roundup(offset + bytes, RK3399_NBYTES) / RK3399_NBYTES;
+ addr_offset = offset % RK3399_NBYTES;
+ addr_len = addr_end - addr_start;
+
+ buf = kzalloc(array3_size(addr_len, RK3399_NBYTES, sizeof(*buf)),
+ GFP_KERNEL);
+ if (!buf) {
+ ret = -ENOMEM;
+ goto nomem;
+ }
+
+ while (addr_len--) {
+ writel(RK3328_AUTO_RD | RK3328_AUTO_ENB |
+ ((addr_start++ & RK3399_A_MASK) << RK3399_A_SHIFT),
+ efuse->base + RK3328_AUTO_CTRL);
+ udelay(4);
+ status = readl(efuse->base + RK3328_INT_STATUS);
+ if (!(status & RK3328_INT_FINISH)) {
+ ret = -EIO;
+ goto err;
+ }
+ out_value = readl(efuse->base + RK3328_DOUT);
+ writel(RK3328_INT_FINISH, efuse->base + RK3328_INT_STATUS);
+
+ memcpy(&buf[i], &out_value, RK3399_NBYTES);
+ i += RK3399_NBYTES;
+ }
+
+ memcpy(val, buf + addr_offset, bytes);
+err:
+ kfree(buf);
+nomem:
+ clk_disable_unprepare(efuse->clk);
+
+ return ret;
+}
+
+static int rockchip_rk3399_efuse_read(void *context, unsigned int offset,
+ void *val, size_t bytes)
+{
+ struct rockchip_efuse_chip *efuse = context;
+ unsigned int addr_start, addr_end, addr_offset, addr_len;
+ u32 out_value;
+ u8 *buf;
+ int ret, i = 0;
+
+ ret = clk_prepare_enable(efuse->clk);
+ if (ret < 0) {
+ dev_err(efuse->dev, "failed to prepare/enable efuse clk\n");
+ return ret;
+ }
+
+ addr_start = rounddown(offset, RK3399_NBYTES) / RK3399_NBYTES;
+ addr_end = roundup(offset + bytes, RK3399_NBYTES) / RK3399_NBYTES;
+ addr_offset = offset % RK3399_NBYTES;
+ addr_len = addr_end - addr_start;
+
+ buf = kzalloc(array3_size(addr_len, RK3399_NBYTES, sizeof(*buf)),
+ GFP_KERNEL);
+ if (!buf) {
+ clk_disable_unprepare(efuse->clk);
+ return -ENOMEM;
+ }
+
+ writel(RK3399_LOAD | RK3399_PGENB | RK3399_STROBSFTSEL | RK3399_RSB,
+ efuse->base + REG_EFUSE_CTRL);
+ udelay(1);
+ while (addr_len--) {
+ writel(readl(efuse->base + REG_EFUSE_CTRL) | RK3399_STROBE |
+ ((addr_start++ & RK3399_A_MASK) << RK3399_A_SHIFT),
+ efuse->base + REG_EFUSE_CTRL);
+ udelay(1);
+ out_value = readl(efuse->base + REG_EFUSE_DOUT);
+ writel(readl(efuse->base + REG_EFUSE_CTRL) & (~RK3399_STROBE),
+ efuse->base + REG_EFUSE_CTRL);
+ udelay(1);
+
+ memcpy(&buf[i], &out_value, RK3399_NBYTES);
+ i += RK3399_NBYTES;
+ }
+
+ /* Switch to standby mode */
+ writel(RK3399_PD | RK3399_CSB, efuse->base + REG_EFUSE_CTRL);
+
+ memcpy(val, buf + addr_offset, bytes);
+
+ kfree(buf);
+
+ clk_disable_unprepare(efuse->clk);
+
+ return 0;
+}
+
+static struct nvmem_config econfig = {
+ .name = "rockchip-efuse",
+ .stride = 1,
+ .word_size = 1,
+ .read_only = true,
+};
+
+static const struct of_device_id rockchip_efuse_match[] = {
+ /* deprecated but kept around for dts binding compatibility */
+ {
+ .compatible = "rockchip,rockchip-efuse",
+ .data = (void *)&rockchip_rk3288_efuse_read,
+ },
+ {
+ .compatible = "rockchip,rk3066a-efuse",
+ .data = (void *)&rockchip_rk3288_efuse_read,
+ },
+ {
+ .compatible = "rockchip,rk3188-efuse",
+ .data = (void *)&rockchip_rk3288_efuse_read,
+ },
+ {
+ .compatible = "rockchip,rk3228-efuse",
+ .data = (void *)&rockchip_rk3288_efuse_read,
+ },
+ {
+ .compatible = "rockchip,rk3288-efuse",
+ .data = (void *)&rockchip_rk3288_efuse_read,
+ },
+ {
+ .compatible = "rockchip,rk3368-efuse",
+ .data = (void *)&rockchip_rk3288_efuse_read,
+ },
+ {
+ .compatible = "rockchip,rk3328-efuse",
+ .data = (void *)&rockchip_rk3328_efuse_read,
+ },
+ {
+ .compatible = "rockchip,rk3399-efuse",
+ .data = (void *)&rockchip_rk3399_efuse_read,
+ },
+ { /* sentinel */},
+};
+MODULE_DEVICE_TABLE(of, rockchip_efuse_match);
+
+static int rockchip_efuse_probe(struct device_d *dev)
+{
+ struct resource *res;
+ struct nvmem_device *nvmem;
+ struct rockchip_efuse_chip *efuse;
+ const void *data;
+
+ data = device_get_match_data(dev);
+ if (!data) {
+ dev_err(dev, "failed to get match data\n");
+ return -EINVAL;
+ }
+
+ efuse = kzalloc(sizeof(struct rockchip_efuse_chip), GFP_KERNEL);
+ if (!efuse)
+ return -ENOMEM;
+
+ res = dev_request_mem_resource(dev, 0);
+ if (IS_ERR(res))
+ return PTR_ERR(res);
+
+ efuse->base = IOMEM(res->start);
+
+ efuse->clk = clk_get(dev, "pclk_efuse");
+ if (IS_ERR(efuse->clk))
+ return PTR_ERR(efuse->clk);
+
+ efuse->dev = dev;
+ if (of_property_read_u32(dev->device_node, "rockchip,efuse-size",
+ &econfig.size))
+ econfig.size = resource_size(res);
+ econfig.reg_read = data;
+ econfig.priv = efuse;
+ econfig.dev = efuse->dev;
+ nvmem = nvmem_register(&econfig);
+
+ return PTR_ERR_OR_ZERO(nvmem);
+}
+
+static struct driver_d rockchip_efuse_driver = {
+ .name = "rockchip-efuse",
+ .of_compatible = rockchip_efuse_match,
+ .probe = rockchip_efuse_probe,
+};
+device_platform_driver(rockchip_efuse_driver);
+MODULE_DESCRIPTION("rockchip_efuse driver");
+MODULE_LICENSE("GPL v2");
--
2.30.2
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