From 4352b8aee98005853aa63f57d6377282de17a33f Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 23 Aug 2026 13:28:57 -0700 Subject: Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ... --- drivers/nvmem/microchip-otpc.c | 289 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 289 insertions(+) create mode 100644 drivers/nvmem/microchip-otpc.c (limited to 'drivers/nvmem/microchip-otpc.c') diff --git a/drivers/nvmem/microchip-otpc.c b/drivers/nvmem/microchip-otpc.c new file mode 100644 index 000000000..df979e854 --- /dev/null +++ b/drivers/nvmem/microchip-otpc.c @@ -0,0 +1,289 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * OTP Memory controller + * + * Copyright (C) 2022 Microchip Technology Inc. and its subsidiaries + * + * Author: Claudiu Beznea + */ + +#include +#include +#include +#include +#include +#include + +#define MCHP_OTPC_CR (0x0) +#define MCHP_OTPC_CR_READ BIT(6) +#define MCHP_OTPC_MR (0x4) +#define MCHP_OTPC_MR_ADDR GENMASK(31, 16) +#define MCHP_OTPC_AR (0x8) +#define MCHP_OTPC_SR (0xc) +#define MCHP_OTPC_SR_READ BIT(6) +#define MCHP_OTPC_HR (0x20) +#define MCHP_OTPC_HR_SIZE GENMASK(15, 8) +#define MCHP_OTPC_DR (0x24) + +#define MCHP_OTPC_NAME "mchp-otpc" +#define MCHP_OTPC_SIZE (11 * 1024) + +/** + * struct mchp_otpc - OTPC private data structure + * @base: base address + * @dev: struct device pointer + * @packets: list of packets in OTP memory + * @npackets: number of packets in OTP memory + */ +struct mchp_otpc { + void __iomem *base; + struct device *dev; + struct list_head packets; + u32 npackets; +}; + +/** + * struct mchp_otpc_packet - OTPC packet data structure + * @list: list head + * @id: packet ID + * @offset: packet offset (in words) in OTP memory + */ +struct mchp_otpc_packet { + struct list_head list; + u32 id; + u32 offset; +}; + +static struct mchp_otpc_packet *mchp_otpc_id_to_packet(struct mchp_otpc *otpc, + u32 id) +{ + struct mchp_otpc_packet *packet; + + if (id >= otpc->npackets) + return NULL; + + list_for_each_entry(packet, &otpc->packets, list) { + if (packet->id == id) + return packet; + } + + return NULL; +} + +static int mchp_otpc_prepare_read(struct mchp_otpc *otpc, + unsigned int offset) +{ + u32 tmp; + + /* Set address. */ + tmp = readl_relaxed(otpc->base + MCHP_OTPC_MR); + tmp &= ~MCHP_OTPC_MR_ADDR; + tmp |= FIELD_PREP(MCHP_OTPC_MR_ADDR, offset); + writel_relaxed(tmp, otpc->base + MCHP_OTPC_MR); + + /* Set read. */ + tmp = readl_relaxed(otpc->base + MCHP_OTPC_CR); + tmp |= MCHP_OTPC_CR_READ; + writel_relaxed(tmp, otpc->base + MCHP_OTPC_CR); + + /* Wait for packet to be transferred into temporary buffers. */ + return read_poll_timeout(readl_relaxed, tmp, !(tmp & MCHP_OTPC_SR_READ), + 10000, 2000, false, otpc->base + MCHP_OTPC_SR); +} + +/* + * OTPC memory is organized into packets. Each packets contains a header and + * a payload. Header is 4 bytes long and contains the size of the payload. + * Payload size varies. The memory footprint is something as follows: + * + * Memory offset Memory footprint Packet ID + * ------------- ---------------- --------- + * + * 0x0 +------------+ <-- packet 0 + * | header 0 | + * 0x4 +------------+ + * | payload 0 | + * . . + * . ... . + * . . + * offset1 +------------+ <-- packet 1 + * | header 1 | + * offset1 + 0x4 +------------+ + * | payload 1 | + * . . + * . ... . + * . . + * offset2 +------------+ <-- packet 2 + * . . + * . ... . + * . . + * offsetN +------------+ <-- packet N + * | header N | + * offsetN + 0x4 +------------+ + * | payload N | + * . . + * . ... . + * . . + * +------------+ + * + * where offset1, offset2, offsetN depends on the size of payload 0, payload 1, + * payload N-1. + * + * The access to memory is done on a per packet basis: the control registers + * need to be updated with an offset address (within a packet range) and the + * data registers will be update by controller with information contained by + * that packet. E.g. if control registers are updated with any address within + * the range [offset1, offset2) the data registers are updated by controller + * with packet 1. Header data is accessible though MCHP_OTPC_HR register. + * Payload data is accessible though MCHP_OTPC_DR and MCHP_OTPC_AR registers. + * There is no direct mapping b/w the offset requested by software and the + * offset returned by hardware. + * + * For this, the read function will return the first requested bytes in the + * packet. The user will have to be aware of the memory footprint before doing + * the read request. + */ +static int mchp_otpc_read(void *priv, unsigned int off, void *val, + size_t bytes) +{ + struct mchp_otpc *otpc = priv; + struct mchp_otpc_packet *packet; + u32 *buf = val; + u32 offset; + size_t len = 0; + int ret, payload_size; + + /* + * We reach this point with off being multiple of stride = 4 to + * be able to cross the subsystem. Inside the driver we use continuous + * unsigned integer numbers for packet id, thus divide off by 4 + * before passing it to mchp_otpc_id_to_packet(). + */ + packet = mchp_otpc_id_to_packet(otpc, off / 4); + if (!packet) + return -EINVAL; + offset = packet->offset; + + while (len < bytes) { + ret = mchp_otpc_prepare_read(otpc, offset); + if (ret) + return ret; + + /* Read and save header content. */ + *buf++ = readl_relaxed(otpc->base + MCHP_OTPC_HR); + len += sizeof(*buf); + offset++; + if (len >= bytes) + break; + + /* Read and save payload content. */ + payload_size = FIELD_GET(MCHP_OTPC_HR_SIZE, *(buf - 1)); + writel_relaxed(0UL, otpc->base + MCHP_OTPC_AR); + do { + *buf++ = readl_relaxed(otpc->base + MCHP_OTPC_DR); + len += sizeof(*buf); + offset++; + payload_size--; + } while (payload_size >= 0 && len < bytes); + } + + return 0; +} + +static int mchp_otpc_init_packets_list(struct mchp_otpc *otpc, u32 *size) +{ + struct mchp_otpc_packet *packet; + u32 word, word_pos = 0, id = 0, npackets = 0, payload_size; + int ret; + + INIT_LIST_HEAD(&otpc->packets); + *size = 0; + + while (*size < MCHP_OTPC_SIZE) { + ret = mchp_otpc_prepare_read(otpc, word_pos); + if (ret) + return ret; + + word = readl_relaxed(otpc->base + MCHP_OTPC_HR); + payload_size = FIELD_GET(MCHP_OTPC_HR_SIZE, word); + if (!payload_size) + break; + + packet = devm_kzalloc(otpc->dev, sizeof(*packet), GFP_KERNEL); + if (!packet) + return -ENOMEM; + + packet->id = id++; + packet->offset = word_pos; + INIT_LIST_HEAD(&packet->list); + list_add_tail(&packet->list, &otpc->packets); + + /* Count size by adding header and paload sizes. */ + *size += 4 * (payload_size + 1); + /* Next word: this packet (header, payload) position + 1. */ + word_pos += payload_size + 2; + + npackets++; + } + + otpc->npackets = npackets; + + return 0; +} + +static struct nvmem_config mchp_nvmem_config = { + .name = MCHP_OTPC_NAME, + .type = NVMEM_TYPE_OTP, + .read_only = true, + .word_size = 4, + .stride = 4, + .reg_read = mchp_otpc_read, +}; + +static int mchp_otpc_probe(struct platform_device *pdev) +{ + struct nvmem_device *nvmem; + struct mchp_otpc *otpc; + u32 size; + int ret; + + otpc = devm_kzalloc(&pdev->dev, sizeof(*otpc), GFP_KERNEL); + if (!otpc) + return -ENOMEM; + + otpc->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(otpc->base)) + return PTR_ERR(otpc->base); + + otpc->dev = &pdev->dev; + ret = mchp_otpc_init_packets_list(otpc, &size); + if (ret) + return ret; + + mchp_nvmem_config.dev = otpc->dev; + mchp_nvmem_config.add_legacy_fixed_of_cells = true; + mchp_nvmem_config.size = size; + mchp_nvmem_config.priv = otpc; + nvmem = devm_nvmem_register(&pdev->dev, &mchp_nvmem_config); + + return PTR_ERR_OR_ZERO(nvmem); +} + +static const struct of_device_id __maybe_unused mchp_otpc_ids[] = { + { .compatible = "microchip,sama7g5-otpc", }, + { }, +}; +MODULE_DEVICE_TABLE(of, mchp_otpc_ids); + +static struct platform_driver mchp_otpc_driver = { + .probe = mchp_otpc_probe, + .driver = { + .name = MCHP_OTPC_NAME, + .of_match_table = of_match_ptr(mchp_otpc_ids), + }, +}; +module_platform_driver(mchp_otpc_driver); + +MODULE_AUTHOR("Claudiu Beznea "); +MODULE_DESCRIPTION("Microchip SAMA7G5 OTPC driver"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1