@@ -0,0 +1,476 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * This library implements NXP's EzPort protocol used to
+ * flash the firmware of Kinetis microcontrollers, such
+ * as https://www.nxp.com/part/MK20FN1M0VMD12 and is
+ * intended to be used as ancillary SPI device.
+ *
+ * Copyright (C) 2018-2021 Collabora
+ * Copyright (C) 2018-2021 GE Healthcare
+ */
+
+#include <linux/delay.h>
+#include <linux/firmware.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/gpio/consumer.h>
+#include <linux/spi/spi.h>
+#include <linux/platform_data/nxp-ezport.h>
+
+#define EZPORT_RESET_DELAY_MS 100
+#define EZPORT_STARTUP_DELAY_MS 200
+#define EZPORT_WRITE_WAIT_MS 10
+#define EZPORT_TRANSFER_SIZE 2048
+
+#define EZPORT_CMD_SP 0x02 /* flash section program */
+#define EZPORT_CMD_RDSR 0x05 /* read status register */
+#define EZPORT_CMD_WREN 0x06 /* write enable */
+#define EZPORT_CMD_FAST_READ 0x0b /* flash read data at high speed */
+#define EZPORT_CMD_RESET 0xb9 /* reset chip */
+#define EZPORT_CMD_BE 0xc7 /* bulk erase */
+#define EZPORT_CMD_SE 0xd8 /* sector erase */
+
+#define EZPORT_SECTOR_SIZE 4096
+#define EZPORT_SECTOR_MASK (EZPORT_SECTOR_SIZE - 1)
+
+#define EZPORT_STATUS_WIP BIT(0) /* write in progress */
+#define EZPORT_STATUS_WEN BIT(1) /* write enable */
+#define EZPORT_STATUS_BEDIS BIT(2) /* bulk erase disable */
+#define EZPORT_STATUS_FLEXRAM BIT(3) /* FlexRAM mode */
+#define EZPORT_STATUS_WEF BIT(6) /* write error flag */
+#define EZPORT_STATUS_FS BIT(7) /* flash security */
+
+/**
+ * ezport_reset - reset ezport device
+ * @reset: the gpio connected to the device reset pin
+ *
+ * Context: can sleep
+ */
+void ezport_reset(struct gpio_desc *reset)
+{
+ gpiod_set_value(reset, 1);
+ msleep(EZPORT_RESET_DELAY_MS);
+ gpiod_set_value(reset, 0);
+ msleep(EZPORT_STARTUP_DELAY_MS);
+}
+EXPORT_SYMBOL_GPL(ezport_reset);
+
+static int ezport_start_programming(struct spi_device *spi, struct gpio_desc *reset)
+{
+ struct spi_message msg;
+ struct spi_transfer assert_cs = {
+ .cs_change = 1,
+ };
+ struct spi_transfer release_cs = { };
+ int ret;
+
+ spi_bus_lock(spi->master);
+
+ /* assert chip select */
+ spi_message_init(&msg);
+ spi_message_add_tail(&assert_cs, &msg);
+ ret = spi_sync_locked(spi, &msg);
+ if (ret)
+ goto fail;
+
+ msleep(EZPORT_STARTUP_DELAY_MS);
+
+ /* reset with asserted chip select to switch into programming mode */
+ ezport_reset(reset);
+
+ /* release chip select */
+ spi_message_init(&msg);
+ spi_message_add_tail(&release_cs, &msg);
+ ret = spi_sync_locked(spi, &msg);
+
+fail:
+ spi_bus_unlock(spi->master);
+ return ret;
+}
+
+static void ezport_stop_programming(struct spi_device *spi, struct gpio_desc *reset)
+{
+ /* reset without asserted chip select to return into normal mode */
+ spi_bus_lock(spi->master);
+ ezport_reset(reset);
+ spi_bus_unlock(spi->master);
+}
+
+static int ezport_get_status_register(struct spi_device *spi)
+{
+ int ret;
+
+ ret = spi_w8r8(spi, EZPORT_CMD_RDSR);
+ if (ret < 0)
+ return ret;
+ if (ret == 0xff) {
+ dev_err(&spi->dev, "Invalid EzPort status, EzPort is not functional!\n");
+ return -EINVAL;
+ }
+
+ return ret;
+}
+
+static int ezport_soft_reset(struct spi_device *spi)
+{
+ u8 cmd = EZPORT_CMD_RESET;
+ int ret;
+
+ ret = spi_write(spi, &cmd, 1);
+ if (ret < 0)
+ return ret;
+
+ msleep(EZPORT_STARTUP_DELAY_MS);
+
+ return 0;
+}
+
+static int ezport_send_simple(struct spi_device *spi, u8 cmd)
+{
+ int ret;
+
+ ret = spi_write(spi, &cmd, 1);
+ if (ret < 0)
+ return ret;
+
+ return ezport_get_status_register(spi);
+}
+
+static int ezport_wait_write(struct spi_device *spi, u32 retries)
+{
+ int ret;
+ u32 i;
+
+ for (i = 0; i < retries; i++) {
+ ret = ezport_get_status_register(spi);
+ if (ret > 0 && !(ret & EZPORT_STATUS_WIP))
+ break;
+ msleep(EZPORT_WRITE_WAIT_MS);
+ }
+
+ return ret;
+}
+
+static int ezport_write_enable(struct spi_device *spi)
+{
+ int ret = 0, retries = 3;
+
+ for (retries = 0; retries < 3; retries++) {
+ ret = ezport_send_simple(spi, EZPORT_CMD_WREN);
+ if (ret > 0 && ret & EZPORT_STATUS_WEN)
+ break;
+ }
+
+ if (!(ret & EZPORT_STATUS_WEN)) {
+ dev_err(&spi->dev, "EzPort write enable timed out\n");
+ return -ETIMEDOUT;
+ }
+ return 0;
+}
+
+static int ezport_bulk_erase(struct spi_device *spi)
+{
+ int ret;
+ static const u8 cmd = EZPORT_CMD_BE;
+
+ dev_dbg(&spi->dev, "EzPort bulk erase...\n");
+
+ ret = ezport_write_enable(spi);
+ if (ret < 0)
+ return ret;
+
+ ret = spi_write(spi, &cmd, 1);
+ if (ret < 0)
+ return ret;
+
+ ret = ezport_wait_write(spi, 1000);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static int ezport_section_erase(struct spi_device *spi, u32 address)
+{
+ u8 query[] = {EZPORT_CMD_SE, (address >> 16) & 0xff, (address >> 8) & 0xff, address & 0xff};
+ int ret;
+
+ dev_dbg(&spi->dev, "Ezport section erase @ 0x%06x...\n", address);
+
+ if (address & EZPORT_SECTOR_MASK)
+ return -EINVAL;
+
+ ret = ezport_write_enable(spi);
+ if (ret < 0)
+ return ret;
+
+ ret = spi_write(spi, query, sizeof(query));
+ if (ret < 0)
+ return ret;
+
+ return ezport_wait_write(spi, 200);
+}
+
+static int ezport_flash_transfer(struct spi_device *spi, u32 address,
+ const u8 *payload, size_t payload_size)
+{
+ struct spi_transfer xfers[2] = {};
+ u8 *command;
+ int ret;
+
+ dev_dbg(&spi->dev, "EzPort write %zu bytes @ 0x%06x...\n", payload_size, address);
+
+ command = kmalloc(4, GFP_KERNEL | GFP_DMA);
+ if (!command)
+ return -ENOMEM;
+
+ command[0] = EZPORT_CMD_SP;
+ command[1] = address >> 16;
+ command[2] = address >> 8;
+ command[3] = address >> 0;
+
+ xfers[0].tx_buf = command;
+ xfers[0].len = 4;
+
+ xfers[1].tx_buf = payload;
+ xfers[1].len = payload_size;
+
+ ret = spi_sync_transfer(spi, xfers, 2);
+ kfree(command);
+ if (ret < 0)
+ return ret;
+
+ return ezport_wait_write(spi, 40);
+}
+
+static int ezport_flash_compare(struct spi_device *spi, u32 address,
+ const u8 *payload, size_t payload_size)
+{
+ struct spi_transfer xfers[2] = {};
+ u8 *buffer;
+ int ret;
+
+ buffer = kmalloc(payload_size + 4, GFP_KERNEL | GFP_DMA);
+ if (!buffer)
+ return -ENOMEM;
+
+ buffer[0] = EZPORT_CMD_FAST_READ;
+ buffer[1] = address >> 16;
+ buffer[2] = address >> 8;
+ buffer[3] = address >> 0;
+
+ xfers[0].tx_buf = buffer;
+ xfers[0].len = 4;
+
+ xfers[1].rx_buf = buffer + 4;
+ xfers[1].len = payload_size;
+
+ ret = spi_sync_transfer(spi, xfers, 2);
+ if (ret)
+ goto err;
+
+ ret = memcmp(payload, buffer + 4, payload_size);
+ if (ret) {
+ ret = -EBADMSG;
+ dev_dbg(&spi->dev, "Verfication failure @ %06x", address);
+ print_hex_dump_bytes("fw: ", DUMP_PREFIX_OFFSET, payload, payload_size);
+ print_hex_dump_bytes("dev: ", DUMP_PREFIX_OFFSET, buffer + 4, payload_size);
+ }
+
+err:
+ kfree(buffer);
+ return ret;
+}
+
+static int ezport_firmware_compare_data(struct spi_device *spi,
+ const u8 *data, size_t size)
+{
+ int ret;
+ u32 address = 0;
+ u32 transfer_size;
+
+ dev_dbg(&spi->dev, "EzPort compare data with %zu bytes...\n", size);
+
+ ret = ezport_get_status_register(spi);
+ if (ret < 0)
+ return ret;
+
+ if (ret & EZPORT_STATUS_FS) {
+ dev_info(&spi->dev, "Device is in secure mode (status=0x%02x)!\n", ret);
+ dev_info(&spi->dev, "FW verification is not possible\n");
+ return -EACCES;
+ }
+
+ while (size - address > 0) {
+ transfer_size = min((u32) EZPORT_TRANSFER_SIZE, size - address);
+
+ ret = ezport_flash_compare(spi, address, data+address, transfer_size);
+ if (ret)
+ return ret;
+
+ address += transfer_size;
+ }
+
+ return 0;
+}
+
+static int ezport_firmware_flash_data(struct spi_device *spi,
+ const u8 *data, size_t size)
+{
+ int ret;
+ u32 address = 0;
+ u32 transfer_size;
+
+ dev_dbg(&spi->dev, "EzPort flash data with %zu bytes...\n", size);
+
+ ret = ezport_get_status_register(spi);
+ if (ret < 0)
+ return ret;
+
+ if (ret & EZPORT_STATUS_FS) {
+ ret = ezport_bulk_erase(spi);
+ if (ret < 0)
+ return ret;
+ if (ret & EZPORT_STATUS_FS)
+ return -EINVAL;
+ }
+
+ while (size - address > 0) {
+ if (!(address & EZPORT_SECTOR_MASK)) {
+ ret = ezport_section_erase(spi, address);
+ if (ret < 0)
+ return ret;
+ if (ret & EZPORT_STATUS_WIP || ret & EZPORT_STATUS_WEF)
+ return -EIO;
+ }
+
+ transfer_size = min((u32) EZPORT_TRANSFER_SIZE, size - address);
+
+ ret = ezport_flash_transfer(spi, address,
+ data+address, transfer_size);
+ if (ret < 0)
+ return ret;
+ else if (ret & EZPORT_STATUS_WIP)
+ return -ETIMEDOUT;
+ else if (ret & EZPORT_STATUS_WEF)
+ return -EIO;
+
+ address += transfer_size;
+ }
+
+ ret = ezport_soft_reset(spi);
+ if (ret < 0)
+ dev_warn(&spi->dev, "EzPort reset failed!\n");
+
+ dev_dbg(&spi->dev, "EzPort verify flashed data...\n");
+ ret = ezport_firmware_compare_data(spi, data, size);
+
+ /* allow missing FW verfication in secure mode */
+ if (ret == -EACCES)
+ ret = 0;
+
+ if (ret < 0)
+ dev_err(&spi->dev, "Failed to verify flashed data: %d\n", ret);
+
+ return ret;
+}
+
+static int ezport_firmware_load(struct spi_device *spi, const char *fwname)
+{
+ const struct firmware *fw;
+ int ret;
+
+ ret = request_firmware(&fw, fwname, &spi->dev);
+ if (ret) {
+ dev_err(&spi->dev, "Could not get firmware: %d\n", ret);
+ return ret;
+ }
+
+ ret = ezport_firmware_flash_data(spi, fw->data, fw->size);
+
+ release_firmware(fw);
+
+ return ret;
+}
+
+static int ezport_firmware_verify(struct spi_device *spi, const char *fwname)
+{
+ const struct firmware *fw;
+ int ret;
+
+ ret = request_firmware(&fw, fwname, &spi->dev);
+ if (ret) {
+ dev_err(&spi->dev, "Could not get firmware: %d\n", ret);
+ return ret;
+ }
+
+ ret = ezport_firmware_compare_data(spi, fw->data, fw->size);
+
+ release_firmware(fw);
+
+ return ret;
+}
+
+/**
+ * ezport_flash - flash device firmware
+ * @spi: SPI device for NXP EzPort interface
+ * @reset: the gpio connected to the device reset pin
+ * @fwname: filename of the firmware that should be flashed
+ *
+ * Context: can sleep
+ *
+ * Return: 0 on success; negative errno on failure
+ */
+int ezport_flash(struct spi_device *spi, struct gpio_desc *reset, const char *fwname)
+{
+ int ret;
+
+ ret = ezport_start_programming(spi, reset);
+ if (ret)
+ return ret;
+
+ ret = ezport_firmware_load(spi, fwname);
+
+ ezport_stop_programming(spi, reset);
+
+ if (ret)
+ dev_err(&spi->dev, "Failed to flash firmware: %d\n", ret);
+ else
+ dev_dbg(&spi->dev, "Finished FW flashing!\n");
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(ezport_flash);
+
+/**
+ * ezport_verify - verify device firmware
+ * @spi: SPI device for NXP EzPort interface
+ * @reset: the gpio connected to the device reset pin
+ * @fwname: filename of the firmware that should be compared
+ *
+ * Context: can sleep
+ *
+ * Return: 0 on success; negative errno on failure
+ */
+int ezport_verify(struct spi_device *spi, struct gpio_desc *reset, const char *fwname)
+{
+ int ret;
+
+ ret = ezport_start_programming(spi, reset);
+ if (ret)
+ return ret;
+
+ ret = ezport_firmware_verify(spi, fwname);
+
+ ezport_stop_programming(spi, reset);
+
+ if (ret)
+ dev_err(&spi->dev, "Failed to verify firmware: %d\n", ret);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(ezport_verify);
+
+MODULE_DESCRIPTION("NXP EzPort protocol support");
+MODULE_AUTHOR("Sebastian Reichel <sebastian.reichel@collabora.com>");
+MODULE_LICENSE("GPL");