[PATCH 1/2] nvmem: Add Rockchip OTP controller driver

[Alexander Shiyan <eagle.alexander923@gmail.com>]

This adds a simple driver to dump specified values of Rockchip SoC
from otp, such as cpu-leakage, id etc.

Signed-off-by: Alexander Shiyan <eagle.alexander923@gmail.com>
---
 drivers/nvmem/Kconfig        |   7 +
 drivers/nvmem/Makefile       |   1 +
 drivers/nvmem/rockchip-otp.c | 448 +++++++++++++++++++++++++++++++++++
 3 files changed, 456 insertions(+)
 create mode 100644 drivers/nvmem/rockchip-otp.c

diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 2e60734156..bea356c900 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -58,6 +58,13 @@ config EEPROM_93XX46
 	  supports both read and write commands and also the command to
 	  erase the whole EEPROM.
 
+config NVMEM_ROCKCHIP_OTP
+	tristate "Rockchip OTP controller support"
+	depends on ARCH_ROCKCHIP || COMPILE_TEST
+	help
+	  This is a simple driver to dump specified values of Rockchip SoC
+	  from otp, such as cpu-leakage, id etc.
+
 config STM32_BSEC
 	tristate "STM32 Boot and security and OTP control"
 	depends on ARCH_STM32MP
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index 62a1f925dd..a3f3c31602 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -27,4 +27,5 @@ nvmem_bsec-y			:= bsec.o
 obj-$(CONFIG_KVX_OTP_NV)	+= nvmem-kvx-otp-nv.o
 nvmem-kvx-otp-nv-y		:= kvx-otp-nv.o
 
+obj-$(CONFIG_NVMEM_ROCKCHIP_OTP)+= rockchip-otp.o
 obj-$(CONFIG_STARFIVE_OTP)	+= starfive-otp.o
diff --git a/drivers/nvmem/rockchip-otp.c b/drivers/nvmem/rockchip-otp.c
new file mode 100644
index 0000000000..b8da4c5380
--- /dev/null
+++ b/drivers/nvmem/rockchip-otp.c
@@ -0,0 +1,448 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Rockchip OTP Driver
+ *
+ * Copyright (c) 2018 Rockchip Electronics Co. Ltd.
+ * Author: Finley Xiao <finley.xiao@rock-chips.com>
+ */
+
+#include <common.h>
+#include <driver.h>
+#include <init.h>
+#include <of.h>
+#include <of_device.h>
+#include <linux/clk.h>
+#include <linux/iopoll.h>
+#include <linux/nvmem-provider.h>
+#include <linux/reset.h>
+
+/* OTP Register Offsets */
+#define OTPC_SBPI_CTRL			0x0020
+#define OTPC_SBPI_CMD_VALID_PRE		0x0024
+#define OTPC_SBPI_CS_VALID_PRE		0x0028
+#define OTPC_SBPI_STATUS		0x002C
+#define OTPC_USER_CTRL			0x0100
+#define OTPC_USER_ADDR			0x0104
+#define OTPC_USER_ENABLE		0x0108
+#define OTPC_USER_Q			0x0124
+#define OTPC_INT_STATUS			0x0304
+#define OTPC_SBPI_CMD0_OFFSET		0x1000
+#define OTPC_SBPI_CMD1_OFFSET		0x1004
+
+/* OTP Register bits and masks */
+#define OTPC_USER_ADDR_MASK		GENMASK(31, 16)
+#define OTPC_USE_USER			BIT(0)
+#define OTPC_USE_USER_MASK		GENMASK(16, 16)
+#define OTPC_USER_FSM_ENABLE		BIT(0)
+#define OTPC_USER_FSM_ENABLE_MASK	GENMASK(16, 16)
+#define OTPC_SBPI_DONE			BIT(1)
+#define OTPC_USER_DONE			BIT(2)
+
+#define SBPI_DAP_ADDR			0x02
+#define SBPI_DAP_ADDR_SHIFT		8
+#define SBPI_DAP_ADDR_MASK		GENMASK(31, 24)
+#define SBPI_CMD_VALID_MASK		GENMASK(31, 16)
+#define SBPI_DAP_CMD_WRF		0xC0
+#define SBPI_DAP_REG_ECC		0x3A
+#define SBPI_ECC_ENABLE			0x00
+#define SBPI_ECC_DISABLE		0x09
+#define SBPI_ENABLE			BIT(0)
+#define SBPI_ENABLE_MASK		GENMASK(16, 16)
+
+#define OTPC_TIMEOUT			10000
+
+#define RK3568_NBYTES			2
+
+/* RK3588 Register */
+#define RK3588_OTPC_AUTO_CTRL		0x04
+#define RK3588_OTPC_AUTO_EN		0x08
+#define RK3588_OTPC_INT_ST		0x84
+#define RK3588_OTPC_DOUT0		0x20
+#define RK3588_NO_SECURE_OFFSET		0x300
+#define RK3588_NBYTES			4
+#define RK3588_BURST_NUM		1
+#define RK3588_BURST_SHIFT		8
+#define RK3588_ADDR_SHIFT		16
+#define RK3588_AUTO_EN			BIT(0)
+#define RK3588_RD_DONE			BIT(1)
+
+struct rockchip_data {
+	int size;
+	const char * const *clks;
+	int num_clks;
+	int (*reg_read)(void *ctx, unsigned int reg, void *val, size_t val_size);
+};
+
+struct rockchip_otp {
+	struct device *dev;
+	void __iomem *base;
+	struct clk_bulk_data *clks;
+	struct reset_control *rst;
+	const struct rockchip_data *data;
+};
+
+static int rockchip_otp_reset(struct rockchip_otp *otp)
+{
+	int ret;
+
+	ret = reset_control_assert(otp->rst);
+	if (ret) {
+		dev_err(otp->dev, "failed to assert otp phy %d\n", ret);
+		return ret;
+	}
+
+	udelay(2);
+
+	ret = reset_control_deassert(otp->rst);
+	if (ret) {
+		dev_err(otp->dev, "failed to deassert otp phy %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int rockchip_otp_wait_status(struct rockchip_otp *otp,
+				    unsigned int reg, u32 flag)
+{
+	u32 status = 0;
+	int ret;
+
+	ret = readl_poll_timeout(otp->base + reg, status,
+				 (status & flag), OTPC_TIMEOUT);
+	if (ret)
+		return ret;
+
+	/* clean int status */
+	writel(flag, otp->base + reg);
+
+	return 0;
+}
+
+static int rockchip_otp_ecc_enable(struct rockchip_otp *otp, bool enable)
+{
+	int ret = 0;
+
+	writel(SBPI_DAP_ADDR_MASK | (SBPI_DAP_ADDR << SBPI_DAP_ADDR_SHIFT),
+	       otp->base + OTPC_SBPI_CTRL);
+
+	writel(SBPI_CMD_VALID_MASK | 0x1, otp->base + OTPC_SBPI_CMD_VALID_PRE);
+	writel(SBPI_DAP_CMD_WRF | SBPI_DAP_REG_ECC,
+	       otp->base + OTPC_SBPI_CMD0_OFFSET);
+	if (enable)
+		writel(SBPI_ECC_ENABLE, otp->base + OTPC_SBPI_CMD1_OFFSET);
+	else
+		writel(SBPI_ECC_DISABLE, otp->base + OTPC_SBPI_CMD1_OFFSET);
+
+	writel(SBPI_ENABLE_MASK | SBPI_ENABLE, otp->base + OTPC_SBPI_CTRL);
+
+	ret = rockchip_otp_wait_status(otp, OTPC_INT_STATUS, OTPC_SBPI_DONE);
+	if (ret < 0)
+		dev_err(otp->dev, "timeout during ecc_enable\n");
+
+	return ret;
+}
+
+static int px30_otp_read(void *context, unsigned int offset,
+			 void *val, size_t bytes)
+{
+	struct rockchip_otp *otp = context;
+	u8 *buf = val;
+	int ret;
+
+	ret = rockchip_otp_reset(otp);
+	if (ret) {
+		dev_err(otp->dev, "failed to reset otp phy\n");
+		return ret;
+	}
+
+	ret = rockchip_otp_ecc_enable(otp, false);
+	if (ret < 0) {
+		dev_err(otp->dev, "rockchip_otp_ecc_enable err\n");
+		return ret;
+	}
+
+	writel(OTPC_USE_USER | OTPC_USE_USER_MASK, otp->base + OTPC_USER_CTRL);
+	udelay(5);
+	while (bytes--) {
+		writel(offset++ | OTPC_USER_ADDR_MASK,
+		       otp->base + OTPC_USER_ADDR);
+		writel(OTPC_USER_FSM_ENABLE | OTPC_USER_FSM_ENABLE_MASK,
+		       otp->base + OTPC_USER_ENABLE);
+		ret = rockchip_otp_wait_status(otp, OTPC_INT_STATUS, OTPC_USER_DONE);
+		if (ret < 0) {
+			dev_err(otp->dev, "timeout during read setup\n");
+			goto read_end;
+		}
+		*buf++ = readb(otp->base + OTPC_USER_Q);
+	}
+
+read_end:
+	writel(0x0 | OTPC_USE_USER_MASK, otp->base + OTPC_USER_CTRL);
+
+	return ret;
+}
+
+static int rk3568_otp_read(void *context, unsigned int offset, void *val,
+			   size_t bytes)
+{
+	struct rockchip_otp *otp = context;
+	unsigned int addr_start, addr_end, addr_offset, addr_len;
+	u32 out_value;
+	u8 *buf;
+	int ret = 0, i = 0;
+
+	addr_start = rounddown(offset, RK3568_NBYTES) / RK3568_NBYTES;
+	addr_end = roundup(offset + bytes, RK3568_NBYTES) / RK3568_NBYTES;
+	addr_offset = offset % RK3568_NBYTES;
+	addr_len = addr_end - addr_start;
+
+	buf = kzalloc(array3_size(addr_len, RK3568_NBYTES, sizeof(*buf)),
+		      GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = rockchip_otp_reset(otp);
+	if (ret) {
+		dev_err(otp->dev, "failed to reset otp phy\n");
+		goto out;
+	}
+
+	ret = rockchip_otp_ecc_enable(otp, false);
+	if (ret < 0) {
+		dev_err(otp->dev, "rockchip_otp_ecc_enable err\n");
+		goto out;
+	}
+
+	writel(OTPC_USE_USER | OTPC_USE_USER_MASK, otp->base + OTPC_USER_CTRL);
+	udelay(5);
+	while (addr_len--) {
+		writel(addr_start++ | OTPC_USER_ADDR_MASK,
+		       otp->base + OTPC_USER_ADDR);
+		writel(OTPC_USER_FSM_ENABLE | OTPC_USER_FSM_ENABLE_MASK,
+		       otp->base + OTPC_USER_ENABLE);
+		ret = rockchip_otp_wait_status(otp, OTPC_INT_STATUS, OTPC_USER_DONE);
+		if (ret < 0) {
+			dev_err(otp->dev, "timeout during read setup\n");
+			goto read_end;
+		}
+		out_value = readl(otp->base + OTPC_USER_Q);
+		memcpy(&buf[i], &out_value, RK3568_NBYTES);
+		i += RK3568_NBYTES;
+	}
+
+	memcpy(val, buf + addr_offset, bytes);
+
+read_end:
+	writel(0x0 | OTPC_USE_USER_MASK, otp->base + OTPC_USER_CTRL);
+out:
+	kfree(buf);
+
+	return ret;
+}
+
+static int rk3588_otp_read(void *context, unsigned int offset,
+			   void *val, size_t bytes)
+{
+	struct rockchip_otp *otp = context;
+	unsigned int addr_start, addr_end, addr_len;
+	int ret = 0, i = 0;
+	u32 data;
+	u8 *buf;
+
+	addr_start = round_down(offset, RK3588_NBYTES) / RK3588_NBYTES;
+	addr_end = round_up(offset + bytes, RK3588_NBYTES) / RK3588_NBYTES;
+	addr_len = addr_end - addr_start;
+	addr_start += RK3588_NO_SECURE_OFFSET;
+
+	buf = kzalloc(array_size(addr_len, RK3588_NBYTES), GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	while (addr_len--) {
+		writel((addr_start << RK3588_ADDR_SHIFT) |
+		       (RK3588_BURST_NUM << RK3588_BURST_SHIFT),
+		       otp->base + RK3588_OTPC_AUTO_CTRL);
+		writel(RK3588_AUTO_EN, otp->base + RK3588_OTPC_AUTO_EN);
+
+		ret = rockchip_otp_wait_status(otp, RK3588_OTPC_INT_ST,
+					       RK3588_RD_DONE);
+		if (ret < 0) {
+			dev_err(otp->dev, "timeout during read setup\n");
+			goto read_end;
+		}
+
+		data = readl(otp->base + RK3588_OTPC_DOUT0);
+		memcpy(&buf[i], &data, RK3588_NBYTES);
+
+		i += RK3588_NBYTES;
+		addr_start++;
+	}
+
+	memcpy(val, buf + offset % RK3588_NBYTES, bytes);
+
+read_end:
+	kfree(buf);
+
+	return ret;
+}
+
+static int rockchip_otp_read(void *context, unsigned int offset,
+			     void *val, size_t bytes)
+{
+	struct rockchip_otp *otp = context;
+	int ret;
+
+	if (!otp->data || !otp->data->reg_read)
+		return -EINVAL;
+
+	ret = clk_bulk_enable(otp->data->num_clks, otp->clks);
+	if (ret < 0) {
+		dev_err(otp->dev, "failed to prepare/enable clks\n");
+		return ret;
+	}
+
+	ret = otp->data->reg_read(context, offset, val, bytes);
+
+	clk_bulk_disable(otp->data->num_clks, otp->clks);
+
+	return ret;
+}
+
+static struct nvmem_config otp_config = {
+	.name = "rockchip-otp",
+	.read_only = true,
+	.stride = 1,
+	.word_size = 1,
+	.reg_read = rockchip_otp_read,
+};
+
+static const char * const px30_otp_clocks[] = {
+	"otp", "apb_pclk", "phy",
+};
+
+static const struct rockchip_data px30_data = {
+	.size = 0x40,
+	.clks = px30_otp_clocks,
+	.num_clks = ARRAY_SIZE(px30_otp_clocks),
+	.reg_read = px30_otp_read,
+};
+
+static const char * const rk3568_otp_clocks[] = {
+	"usr", "sbpi", "apb", "phy",
+};
+
+static const struct rockchip_data rk3568_data = {
+	.size = 0x80,
+	.clks = rk3568_otp_clocks,
+	.num_clks = ARRAY_SIZE(rk3568_otp_clocks),
+	.reg_read = rk3568_otp_read,
+};
+
+static const char * const rk3588_otp_clocks[] = {
+	"otp", "apb_pclk", "phy", "arb",
+};
+
+static const struct rockchip_data rk3588_data = {
+	.size = 0x400,
+	.clks = rk3588_otp_clocks,
+	.num_clks = ARRAY_SIZE(rk3588_otp_clocks),
+	.reg_read = rk3588_otp_read,
+};
+
+static __maybe_unused const struct of_device_id rockchip_otp_match[] = {
+	{
+		.compatible = "rockchip,px30-otp",
+		.data = &px30_data,
+	},
+	{
+		.compatible = "rockchip,rk3308-otp",
+		.data = &px30_data,
+	},
+	{
+		.compatible = "rockchip,rk3568-otp",
+		.data = &rk3568_data,
+	},
+	{
+		.compatible = "rockchip,rk3588-otp",
+		.data = &rk3588_data,
+	},
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, rockchip_otp_match);
+
+static int rockchip_otp_probe(struct device *dev)
+{
+	struct rockchip_otp *otp;
+	const struct rockchip_data *data;
+	struct nvmem_device *nvmem;
+	struct resource *res;
+	int ret, i;
+
+	data = of_device_get_match_data(dev);
+	if (!data)
+		return dev_err_probe(dev, -EINVAL, "failed to get match data\n");
+
+	otp = kzalloc(sizeof(*otp), GFP_KERNEL);
+	if (!otp)
+		return -ENOMEM;
+
+	res = dev_request_mem_resource(dev, 0);
+	if (IS_ERR(res)) {
+		ret = PTR_ERR(res);
+		goto err_free;
+	}
+
+	otp->data = data;
+	otp->dev = dev;
+	otp->base = IOMEM(res->start);
+
+	otp->clks = kcalloc(data->num_clks, sizeof(*otp->clks), GFP_KERNEL);
+	if (!otp->clks) {
+		ret = -ENOMEM;
+		goto err_free;
+	}
+
+	for (i = 0; i < data->num_clks; ++i)
+		otp->clks[i].id = data->clks[i];
+
+	ret = clk_bulk_get_optional(dev, data->num_clks, otp->clks);
+	if (ret)
+		goto err_clk;
+
+	otp->rst = reset_control_get(dev, NULL);
+	if (IS_ERR(otp->rst)) {
+		ret = PTR_ERR(otp->rst);
+		goto err_rst;
+	}
+
+	otp_config.size = data->size;
+	otp_config.priv = otp;
+	otp_config.dev = dev;
+
+	nvmem = nvmem_register(&otp_config);
+	if (!IS_ERR(nvmem))
+		return 0;
+
+	ret = PTR_ERR(nvmem);
+
+	reset_control_put(otp->rst);
+
+err_rst:
+	clk_bulk_put_all(data->num_clks, otp->clks);
+
+err_clk:
+	kfree(otp->clks);
+
+err_free:
+	kfree(otp);
+
+	return ret;
+}
+
+static struct driver rockchip_otp_driver = {
+	.name	= "rockchip-otp",
+	.probe	= rockchip_otp_probe,
+	.of_compatible = DRV_OF_COMPAT(rockchip_otp_match),
+};
+device_platform_driver(rockchip_otp_driver);
-- 
2.39.1