[PATCH 05/20] nvmem: add StarFive OTP support
Ahmad Fatoum
a.fatoum at pengutronix.de
Mon May 31 00:38:06 PDT 2021
The OTP holds the ethernet MAC address. Add a driver, so barebox can
read it out.
Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
drivers/nvmem/Kconfig | 8 ++
drivers/nvmem/Makefile | 2 +
drivers/nvmem/starfive-otp.c | 227 +++++++++++++++++++++++++++++++++++
3 files changed, 237 insertions(+)
create mode 100644 drivers/nvmem/starfive-otp.c
diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index e4a72b1431a9..377d6c8b15cc 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -59,4 +59,12 @@ config STM32_BSEC
This adds support for the STM32 OTP controller. Reads and writes
to will go to the shadow RAM, not the OTP fuses themselvers.
+config STARFIVE_OTP
+ tristate "Starfive OTP Supprot"
+ depends on SOC_STARFIVE
+ depends on OFDEVICE
+ help
+ This adds support for the StarFive OTP controller. Only reading
+ is currently supported.
+
endif
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index 617e3725a726..83ff3d23cb44 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -20,3 +20,5 @@ nvmem_eeprom_93xx46-y := eeprom_93xx46.o
obj-$(CONFIG_STM32_BSEC) += nvmem_bsec.o
nvmem_bsec-y := bsec.o
+
+obj-$(CONFIG_STARFIVE_OTP) += starfive-otp.o
diff --git a/drivers/nvmem/starfive-otp.c b/drivers/nvmem/starfive-otp.c
new file mode 100644
index 000000000000..5d1a94364d81
--- /dev/null
+++ b/drivers/nvmem/starfive-otp.c
@@ -0,0 +1,227 @@
+// SPDX_License-Identifier: GPL-2.0
+/*
+ * Copyright 2021 StarFive, Inc
+ */
+
+#include <common.h>
+#include <driver.h>
+#include <malloc.h>
+#include <xfuncs.h>
+#include <errno.h>
+#include <gpiod.h>
+#include <init.h>
+#include <net.h>
+#include <io.h>
+#include <of.h>
+#include <regmap.h>
+#include <machine_id.h>
+#include <linux/reset.h>
+#include <linux/nvmem-provider.h>
+
+// otp reg offset
+#define OTP_CFGR 0x00
+#define OTPC_IER 0x04
+#define OTPC_SRR 0x08
+#define OTP_OPRR 0x0c
+#define OTPC_CTLR 0x10
+#define OTPC_ADDRR 0x14
+#define OTPC_DINR 0x18
+#define OTPC_DOUTR 0x1c
+
+#define OTP_EMPTY_CELL_VALUE 0xffffffffUL
+
+// cfgr (offset 0x00)
+#define OTP_CFGR_PRG_CNT_MASK 0xff
+#define OTP_CFGR_PRG_CNT_SHIFT 0
+#define OTP_CFGR_DIV_1US_MASK 0xff
+#define OTP_CFGR_DIV_1US_SHIFT 8
+#define OTP_CFGR_RD_CYC_MASK 0x0f
+#define OTP_CFGR_RD_CYC_SHIFT 16
+
+// ier (offset 0x04)
+#define OTPC_IER_DONE_IE BIT(0)
+#define OTPC_IER_BUSY_OPR_IE BIT(1)
+
+// srr (offset 0x08)
+#define OTPC_SRR_DONE BIT(0)
+#define OTPC_SRR_BUSY_OPR BIT(1)
+#define OTPC_SRR_INFO_RD_LOCK BIT(29)
+#define OTPC_SRR_INFO_WR_LOCK BIT(30)
+#define OTPC_SRR_BUSY BIT(31)
+
+// oprr (offset 0x0c)
+#define OTP_OPRR_OPR_MASK 0x00000007
+#define OTP_OPRR_OPR_SHIFT 0
+
+#define OTP_OPR_STANDBY 0x0 // user mode
+#define OTP_OPR_READ 0x1 // user mode
+#define OTP_OPR_MARGIN_READ_PROG 0x2 // testing mode
+#define OTP_OPR_MARGIN_READ_INIT 0x3 // testing mode
+#define OTP_OPR_PROGRAM 0x4 // user mode
+#define OTP_OPR_DEEP_STANDBY 0x5 // user mode
+#define OTP_OPR_DEBUG 0x6 // user mode
+
+// ctlr (offset 0x10, see EG512X32TH028CW01_v1.0.pdf "Pin Description")
+#define OTPC_CTLR_PCE BIT(0)
+#define OTPC_CTLR_PTM_MASK 0x0000000e
+#define OTPC_CTLR_PTM_SHIFT 1
+#define OTPC_CTLR_PDSTB BIT(4)
+#define OTPC_CTLR_PTR BIT(5)
+#define OTPC_CTLR_PPROG BIT(6)
+#define OTPC_CTLR_PWE BIT(7)
+#define OTPC_CTLR_PCLK BIT(8)
+
+// addrr (offset 0x14)
+#define OTPC_ADDRR_PA_MASK 0x000001ff
+#define OTPC_ADDRR_PA_SHIFT 0
+
+/*
+ * data format:
+ * struct starfive_otp_data{
+ * char vendor[32];
+ * uint64_t sn;
+ * uint8_t mac_addr[6];
+ * uint8_t padding_0[2];
+ * }
+ */
+
+struct starfive_otp {
+ int power_gpio;
+ struct starfive_otp_regs __iomem *regs;
+};
+
+struct starfive_otp_regs {
+ /* TODO: add otp ememory_eg512x32 registers define */
+ u32 otp_cfg; /* timing Register */
+ u32 otpc_ie; /* interrupt Enable */
+ u32 otpc_sr; /* status Register */
+ u32 otp_opr; /* operation mode select Register */
+ u32 otpc_ctl; /* otp control port */
+ u32 otpc_addr; /* otp pa port */
+ u32 otpc_din; /* otp pdin port */
+ u32 otpc_dout; /* otp pdout */
+ u32 reserved[504];
+ u32 mem[512];
+};
+
+/*
+ * offset and size are assumed aligned to the size of the fuses (32-bit).
+ */
+static int starfive_otp_read(void *ctx, unsigned offset, unsigned *val)
+{
+ struct starfive_otp *priv = ctx;
+
+ gpio_set_active(priv->power_gpio, true);
+ mdelay(10);
+
+ //otp set to read mode
+ writel(OTP_OPR_READ, &priv->regs->otp_opr);
+ mdelay(5);
+
+ /* read all requested fuses */
+ *val = readl(&priv->regs->mem[offset / 4]);
+
+ gpio_set_active(priv->power_gpio, false);
+ mdelay(5);
+
+ return 0;
+}
+
+static int starfive_otp_write(void *ctx, unsigned offset, unsigned val)
+{
+ return -EOPNOTSUPP;
+}
+
+static struct regmap_bus starfive_otp_regmap_bus = {
+ .reg_read = starfive_otp_read,
+ .reg_write = starfive_otp_write,
+};
+
+static int starfive_otp_set_mac(struct device_node *rnode, struct regmap *map, unsigned offset)
+{
+ u8 mac[8];
+ int ret;
+
+ ret = regmap_bulk_read(map, offset, mac, 8);
+ if (ret)
+ return ret;
+
+ of_eth_register_ethaddr(rnode, mac);
+ return 0;
+}
+
+static int starfive_otp_probe(struct device_d *dev)
+{
+ struct starfive_otp *priv;
+ struct regmap_config config = {};
+ struct nvmem_device *nvmem;
+ struct resource *iores;
+ const __be32 *prop;
+ struct regmap *map;
+ u32 total_fuses;
+ int len, ret;
+
+ ret = device_reset(dev);
+ if (ret)
+ return ret;
+
+ iores = dev_request_mem_resource(dev, 0);
+ if (IS_ERR(iores))
+ return PTR_ERR(iores);
+
+ ret = of_property_read_u32(dev->device_node, "fuse-count", &total_fuses);
+ if (ret < 0) {
+ dev_err(dev, "missing required fuse-count property\n");
+ return ret;
+ }
+
+ config.name = "starfive-otp";
+ config.reg_bits = 32;
+ config.val_bits = 32;
+ config.reg_stride = 4;
+ config.max_register = total_fuses;
+
+ priv = xzalloc(sizeof(*priv));
+
+ priv->regs = IOMEM(iores->start);
+ priv->power_gpio = gpiod_get(dev, "power", GPIOD_OUT_LOW);
+ if (priv->power_gpio < 0)
+ return priv->power_gpio;
+
+ map = regmap_init(dev, &starfive_otp_regmap_bus, priv, &config);
+ if (IS_ERR(map))
+ return PTR_ERR(map);
+
+ nvmem = nvmem_regmap_register(map, "starfive-otp");
+ if (IS_ERR(nvmem))
+ return PTR_ERR(nvmem);
+
+ prop = of_get_property(dev->device_node, "barebox,provide-mac-address", &len);
+ if (prop && len == 2 * sizeof(__be32)) {
+ struct device_node *rnode;
+ u32 phandle, offset;
+
+ phandle = be32_to_cpup(prop++);
+
+ rnode = of_find_node_by_phandle(phandle);
+ offset = be32_to_cpup(prop++);
+
+ ret = starfive_otp_set_mac(rnode, map, offset);
+ if (ret)
+ dev_warn(dev, "error setting MAC address: %pe\n", ERR_PTR(ret));
+ }
+
+ return 0;
+}
+
+static struct of_device_id starfive_otp_dt_ids[] = {
+ { .compatible = "starfive,fu740-otp" },
+ { /* sentinel */ }
+};
+
+static struct driver_d starfive_otp_driver = {
+ .name = "starfive_otp",
+ .probe = starfive_otp_probe,
+ .of_compatible = starfive_otp_dt_ids,
+};
+device_platform_driver(starfive_otp_driver);
--
2.29.2
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