Re: [PATCH v9 char-misc-next 1/2] misc: microchip: pci1xxxx: Add support to read and write into PCI1XXXX OTP via NVMEM sysfs
From: Michael Walle
Date: Thu Apr 13 2023 - 12:08:46 EST
Am 2023-04-13 12:53, schrieb Vaibhaav Ram T.L:
From: Kumaravel Thiagarajan <kumaravel.thiagarajan@xxxxxxxxxxxxx>
Microchip's pci1xxxx is an unmanaged PCIe3.1a switch for consumer,
industrial, and automotive applications. This switch integrates OTP
and EEPROM to enable customization of the part in the field.
This patch adds support to read and write into PCI1XXXX OTP
via NVMEM sysfs
Thanks for working on that. Now this driver is less of an oddball
one.
Signed-off-by: Kumaravel Thiagarajan
<kumaravel.thiagarajan@xxxxxxxxxxxxx>
Co-developed-by: Tharun Kumar P <tharunkumar.pasumarthi@xxxxxxxxxxxxx>
Signed-off-by: Tharun Kumar P <tharunkumar.pasumarthi@xxxxxxxxxxxxx>
Co-developed-by: Vaibhaav Ram T.L <vaibhaavram.tl@xxxxxxxxxxxxx>
Signed-off-by: Vaibhaav Ram T.L <vaibhaavram.tl@xxxxxxxxxxxxx>
---
MAINTAINERS | 2 +
drivers/misc/mchp_pci1xxxx/Kconfig | 1 +
drivers/misc/mchp_pci1xxxx/Makefile | 2 +-
.../misc/mchp_pci1xxxx/mchp_pci1xxxx_otpe2p.c | 301 ++++++++++++++++++
4 files changed, 305 insertions(+), 1 deletion(-)
create mode 100644 drivers/misc/mchp_pci1xxxx/mchp_pci1xxxx_otpe2p.c
diff --git a/MAINTAINERS b/MAINTAINERS
index a33261b4592f..58e4b9d6ed61 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13721,12 +13721,14 @@
F: Documentation/devicetree/bindings/mtd/atmel-nand.txt
F: drivers/mtd/nand/raw/atmel/*
MICROCHIP PCI1XXXX GP DRIVER
+M: Vaibhaav Ram T.L <vaibhaavram.tl@xxxxxxxxxxxxx>
M: Kumaravel Thiagarajan <kumaravel.thiagarajan@xxxxxxxxxxxxx>
L: linux-gpio@xxxxxxxxxxxxxxx
S: Supported
F: drivers/misc/mchp_pci1xxxx/mchp_pci1xxxx_gp.c
F: drivers/misc/mchp_pci1xxxx/mchp_pci1xxxx_gp.h
F: drivers/misc/mchp_pci1xxxx/mchp_pci1xxxx_gpio.c
+F: drivers/misc/mchp_pci1xxxx/mchp_pci1xxxx_otpe2p.c
MICROCHIP OTPC DRIVER
M: Claudiu Beznea <claudiu.beznea@xxxxxxxxxxxxx>
diff --git a/drivers/misc/mchp_pci1xxxx/Kconfig
b/drivers/misc/mchp_pci1xxxx/Kconfig
index 4abb47de7219..64e457581fb4 100644
--- a/drivers/misc/mchp_pci1xxxx/Kconfig
+++ b/drivers/misc/mchp_pci1xxxx/Kconfig
@@ -2,6 +2,7 @@ config GP_PCI1XXXX
tristate "Microchip PCI1XXXX PCIe to GPIO Expander + OTP/EEPROM
manager"
depends on PCI
depends on GPIOLIB
+ depends on NVMEM_SYSFS
select GPIOLIB_IRQCHIP
select AUXILIARY_BUS
help
diff --git a/drivers/misc/mchp_pci1xxxx/Makefile
b/drivers/misc/mchp_pci1xxxx/Makefile
index fc4615cfe28b..ae31251dab37 100644
--- a/drivers/misc/mchp_pci1xxxx/Makefile
+++ b/drivers/misc/mchp_pci1xxxx/Makefile
@@ -1 +1 @@
-obj-$(CONFIG_GP_PCI1XXXX) := mchp_pci1xxxx_gp.o mchp_pci1xxxx_gpio.o
+obj-$(CONFIG_GP_PCI1XXXX) := mchp_pci1xxxx_gp.o mchp_pci1xxxx_gpio.o
mchp_pci1xxxx_otpe2p.o
diff --git a/drivers/misc/mchp_pci1xxxx/mchp_pci1xxxx_otpe2p.c
b/drivers/misc/mchp_pci1xxxx/mchp_pci1xxxx_otpe2p.c
new file mode 100644
index 000000000000..23f44ad6773e
--- /dev/null
+++ b/drivers/misc/mchp_pci1xxxx/mchp_pci1xxxx_otpe2p.c
@@ -0,0 +1,301 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2022-2023 Microchip Technology Inc.
+// PCI1xxxx OTP/EEPROM driver
+
+#include <linux/auxiliary_bus.h>
+#include <linux/bio.h>
+#include <linux/device.h>
+#include <linux/iopoll.h>
+#include <linux/kthread.h>
Is this needed? I don't see any threads. Also bio.h. Please double check
your includes.
+#include <linux/module.h>
+#include <linux/nvmem-provider.h>
+
+#include "mchp_pci1xxxx_gp.h"
+
+#define AUX_DRIVER_NAME "PCI1xxxxOTPE2P"
+#define OTP_NAME "pci1xxxx_otp"
+
+#define PERI_PF3_SYSTEM_REG_ADDR_BASE 0x2000
+#define PERI_PF3_SYSTEM_REG_LENGTH 0x4000
+
+#define OTP_SIZE_BYTES 8192
+
+#define CONFIG_REG_ADDR_BASE 0
+#define OTP_REG_ADDR_BASE 0x1000
+
+#define MMAP_OTP_OFFSET(x) (OTP_REG_ADDR_BASE + x)
+#define MMAP_CFG_OFFSET(x) (CONFIG_REG_ADDR_BASE + x)
+
+#define STATUS_READ_DELAY_US 1
+#define STATUS_READ_TIMEOUT_US 20000
+
+#define OTP_ADDR_HIGH_OFFSET 0x04
+#define OTP_ADDR_LOW_OFFSET 0x08
+#define OTP_PRGM_DATA_OFFSET 0x10
+#define OTP_PRGM_MODE_OFFSET 0x14
+#define OTP_RD_DATA_OFFSET 0x18
+#define OTP_FUNC_CMD_OFFSET 0x20
+#define OTP_CMD_GO_OFFSET 0x28
+#define OTP_PASS_FAIL_OFFSET 0x2C
+#define OTP_STATUS_OFFSET 0x30
+
+#define OTP_FUNC_RD_BIT BIT(0)
+#define OTP_FUNC_PGM_BIT BIT(1)
+#define OTP_CMD_GO_BIT BIT(0)
+#define OTP_STATUS_BUSY_BIT BIT(0)
+#define OTP_PGM_MODE_BYTE_BIT BIT(0)
+#define OTP_FAIL_BIT BIT(0)
+
+#define OTP_PWR_DN_BIT BIT(0)
+#define OTP_PWR_DN_OFFSET 0x00
+
+#define CFG_SYS_LOCK_OFFSET 0xA0
+#define CFG_SYS_LOCK_PF3 BIT(5)
+
+#define BYTE_LOW (GENMASK(7, 0))
+#define BYTE_HIGH (GENMASK(12, 8))
+
+struct pci1xxxx_otp_eeprom_device {
+ struct auxiliary_device *pdev;
+ void __iomem *reg_base;
+ struct nvmem_config nvmem_config_otp;
+ struct nvmem_device *nvmem_otp;
+};
+
+static int set_sys_lock(struct pci1xxxx_otp_eeprom_device *priv)
+{
+ void __iomem *sys_lock = priv->reg_base +
+ MMAP_CFG_OFFSET(CFG_SYS_LOCK_OFFSET);
+ u8 data;
+
+ writel(CFG_SYS_LOCK_PF3, sys_lock);
+ data = readl(sys_lock);
+ if (data != CFG_SYS_LOCK_PF3)
+ return -EPERM;
+
+ return 0;
+}
+
+static void release_sys_lock(struct pci1xxxx_otp_eeprom_device *priv)
+{
+ void __iomem *sys_lock = priv->reg_base +
+ MMAP_CFG_OFFSET(CFG_SYS_LOCK_OFFSET);
+ writel(0, sys_lock);
+}
+
+static void otp_device_set_address(struct pci1xxxx_otp_eeprom_device
*priv,
+ u16 address)
+{
+ u16 lo, hi;
+
+ lo = address & BYTE_LOW;
+ hi = (address & BYTE_HIGH) >> 8;
+ writew(lo, priv->reg_base + MMAP_OTP_OFFSET(OTP_ADDR_LOW_OFFSET));
+ writew(hi, priv->reg_base + MMAP_OTP_OFFSET(OTP_ADDR_HIGH_OFFSET));
+}
+
+static int pci1xxxx_otp_read(void *priv_t, unsigned int off,
+ void *buf_t, size_t count)
+{
+ struct pci1xxxx_otp_eeprom_device *priv = priv_t;
+ char *buf = buf_t;
+ void __iomem *rb;
+ u32 regval;
+ u32 byte;
+ int ret;
+ u8 data;
+
+ if (priv != NULL)
+ rb = priv->reg_base;
+ else
+ return -ENODEV;
Unneeded check, priv cannot be NULL, right?
+
+ ret = set_sys_lock(priv);
+ if (ret)
+ return ret;
+
+ for (byte = 0; byte < count; byte++) {
+ otp_device_set_address(priv, (u16)(off + byte));
+ data = readl(rb + MMAP_OTP_OFFSET(OTP_FUNC_CMD_OFFSET));
+ writel(data | OTP_FUNC_RD_BIT,
+ rb + MMAP_OTP_OFFSET(OTP_FUNC_CMD_OFFSET));
+ data = readl(rb + MMAP_OTP_OFFSET(OTP_CMD_GO_OFFSET));
+ writel(data | OTP_CMD_GO_BIT,
+ rb + MMAP_OTP_OFFSET(OTP_CMD_GO_OFFSET));
+
+ ret = read_poll_timeout(readl, regval,
+ !(regval & OTP_STATUS_BUSY_BIT),
+ STATUS_READ_DELAY_US,
+ STATUS_READ_TIMEOUT_US, true,
+ rb + MMAP_OTP_OFFSET(OTP_STATUS_OFFSET));
+
+ data = readl(rb + MMAP_OTP_OFFSET(OTP_PASS_FAIL_OFFSET));
+ if (ret < 0 || data & OTP_FAIL_BIT)
+ break;
No error handling?
+
+ buf[byte] = readl(rb + MMAP_OTP_OFFSET(OTP_RD_DATA_OFFSET));
+ }
+ release_sys_lock(priv);
+
+ return byte;
+}
+
+static int pci1xxxx_otp_write(void *priv_t, unsigned int off,
+ void *value_t, size_t count)
+{
+ struct pci1xxxx_otp_eeprom_device *priv = priv_t;
+ char *value = value_t;
+ void __iomem *rb;
+ u32 regval;
+ u32 byte;
+ int ret;
+ u8 data;
+
+ if (priv != NULL)
+ rb = priv->reg_base;
+ else
+ return -ENODEV;
Same as above.
+
+ ret = set_sys_lock(priv);
+ if (ret)
+ return ret;
+
+ for (byte = 0; byte < count; byte++) {
+ otp_device_set_address(priv, (u16)(off + byte));
+
+ /*
+ * Set OTP_PGM_MODE_BYTE command bit in OTP_PRGM_MODE register
+ * to enable Byte programming
+ */
+ data = readl(rb + MMAP_OTP_OFFSET(OTP_PRGM_MODE_OFFSET));
+ writel(data | OTP_PGM_MODE_BYTE_BIT,
+ rb + MMAP_OTP_OFFSET(OTP_PRGM_MODE_OFFSET));
+ writel(*(value + byte), rb + MMAP_OTP_OFFSET(OTP_PRGM_DATA_OFFSET));
+ data = readl(rb + MMAP_OTP_OFFSET(OTP_FUNC_CMD_OFFSET));
+ writel(data | OTP_FUNC_PGM_BIT,
+ rb + MMAP_OTP_OFFSET(OTP_FUNC_CMD_OFFSET));
+ data = readl(rb + MMAP_OTP_OFFSET(OTP_CMD_GO_OFFSET));
+ writel(data | OTP_CMD_GO_BIT,
+ rb + MMAP_OTP_OFFSET(OTP_CMD_GO_OFFSET));
+
+ ret = read_poll_timeout(readl, regval,
+ !(regval & OTP_STATUS_BUSY_BIT),
+ STATUS_READ_DELAY_US,
+ STATUS_READ_TIMEOUT_US, true,
+ rb + MMAP_OTP_OFFSET(OTP_STATUS_OFFSET));
+
+ data = readl(rb + MMAP_OTP_OFFSET(OTP_PASS_FAIL_OFFSET));
+ if (ret < 0 || data & OTP_FAIL_BIT)
+ break;
also here.
+ }
+ release_sys_lock(priv);
+
+ return byte;
+}
+
+static int pci1xxxx_otp_eeprom_probe(struct auxiliary_device *aux_dev,
+ const struct auxiliary_device_id *id)
+{
+ struct auxiliary_device_wrapper *aux_dev_wrapper;
+ struct pci1xxxx_otp_eeprom_device *priv;
+ struct gp_aux_data_type *pdata;
+ int ret;
+ u8 data;
+
+ aux_dev_wrapper = container_of(aux_dev, struct
auxiliary_device_wrapper,
+ aux_dev);
+ pdata = &aux_dev_wrapper->gp_aux_data;
+ if (!pdata)
+ return dev_err_probe(&aux_dev->dev, -EINVAL,
+ "Invalid data in aux_dev_wrapper->gp_aux_data\n");
+
+ priv = devm_kzalloc(&aux_dev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return dev_err_probe(&aux_dev->dev, -ENOMEM,
+ "Memory Allocation Failed\n");
Just return -ENOMEM. No need for that message.
-michael