--- /dev/null
+From 0299de52cbb2274345e12518298a8014adb56411 Mon Sep 17 00:00:00 2001
+From: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
+Date: Thu, 9 Oct 2025 19:33:23 +0300
+Subject: [PATCH 2/2] spi: airoha-snfi: en7523: workaround flash damaging if
+ UART_TXD was short to GND
+
+We found that some serial console may pull TX line to GROUND during board
+boot time. Airoha uses TX line as one of it's BOOT pins. This will lead
+to booting in RESERVED boot mode.
+
+It was found that some flashes operates incorrectly in RESERVED mode.
+Micron and Skyhigh flashes are definitely affected by the issue,
+Winbond flashes are NOT affected.
+
+Details:
+--------
+DMA reading of odd pages on affected flashes operates incorrectly. Page
+reading offset (start of the page) on hardware level is replaced by 0x10.
+Thus results in incorrect data reading. Usage of UBI make things even
+worse. Any attempt to access UBI leads to ubi damaging. As result OS loading
+becomes impossible.
+
+Non-DMA reading is OK.
+
+This patch detects booting in reserved mode, turn off DMA and print big
+fat warning.
+
+Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
+---
+ drivers/spi/spi-airoha-snfi.c | 38 ++++++++++++++++++++++++++++++++---
+ 1 file changed, 35 insertions(+), 3 deletions(-)
+
+--- a/drivers/spi/spi-airoha-snfi.c
++++ b/drivers/spi/spi-airoha-snfi.c
+@@ -1013,6 +1013,11 @@ static const struct spi_controller_mem_o
+ .dirmap_write = airoha_snand_dirmap_write,
+ };
+
++static const struct spi_controller_mem_ops airoha_snand_nodma_mem_ops = {
++ .supports_op = airoha_snand_supports_op,
++ .exec_op = airoha_snand_exec_op,
++};
++
+ static int airoha_snand_setup(struct spi_device *spi)
+ {
+ struct airoha_snand_ctrl *as_ctrl;
+@@ -1059,7 +1064,10 @@ static int airoha_snand_probe(struct pla
+ struct device *dev = &pdev->dev;
+ struct spi_controller *ctrl;
+ void __iomem *base;
+- int err;
++ int err, dma_enabled;
++#if defined(CONFIG_ARM)
++ u32 sfc_strap;
++#endif
+
+ ctrl = devm_spi_alloc_host(dev, sizeof(*as_ctrl));
+ if (!ctrl)
+@@ -1093,12 +1101,36 @@ static int airoha_snand_probe(struct pla
+ return dev_err_probe(dev, PTR_ERR(as_ctrl->spi_clk),
+ "unable to get spi clk\n");
+
+- err = dma_set_mask(as_ctrl->dev, DMA_BIT_MASK(32));
++ dma_enabled = 1;
++#if defined(CONFIG_ARM)
++ err = regmap_read(as_ctrl->regmap_ctrl,
++ REG_SPI_CTRL_SFC_STRAP, &sfc_strap);
+ if (err)
+ return err;
+
++ if (!(sfc_strap & 0x04)) {
++ dma_enabled = 0;
++ printk(KERN_WARNING "\n"
++ "=== WARNING ======================================================\n"
++ "Detected booting in RESERVED mode (UART_TXD was short to GND).\n"
++ "This mode is known for incorrect DMA reading of some flashes.\n"
++ "Usage of DMA for flash operations will be disabled to prevent data\n"
++ "damage. Unplug your serial console and power cycle the board\n"
++ "to boot with full performance.\n"
++ "==================================================================\n\n");
++ }
++#endif
++
++ if (dma_enabled) {
++ err = dma_set_mask(as_ctrl->dev, DMA_BIT_MASK(32));
++ if (err)
++ return err;
++ }
++
+ ctrl->num_chipselect = 2;
+- ctrl->mem_ops = &airoha_snand_mem_ops;
++ ctrl->mem_ops = dma_enabled ?
++ &airoha_snand_mem_ops :
++ &airoha_snand_nodma_mem_ops;
+ ctrl->bits_per_word_mask = SPI_BPW_MASK(8);
+ ctrl->mode_bits = SPI_RX_DUAL;
+ ctrl->setup = airoha_snand_setup;
+++ /dev/null
---- a/drivers/spi/Kconfig
-+++ b/drivers/spi/Kconfig
-@@ -370,6 +370,12 @@ config SPI_DLN2
- This driver can also be built as a module. If so, the module
- will be called spi-dln2.
-
-+config SPI_AIROHA_EN7523
-+ bool "Airoha EN7523 SPI controller support"
-+ depends on ARCH_AIROHA
-+ help
-+ This enables SPI controller support for the Airoha EN7523 SoC.
-+
- config SPI_EP93XX
- tristate "Cirrus Logic EP93xx SPI controller"
- depends on ARCH_EP93XX || COMPILE_TEST
---- a/drivers/spi/Makefile
-+++ b/drivers/spi/Makefile
-@@ -52,6 +52,7 @@ obj-$(CONFIG_SPI_DW_BT1) += spi-dw-bt1.
- obj-$(CONFIG_SPI_DW_MMIO) += spi-dw-mmio.o
- obj-$(CONFIG_SPI_DW_PCI) += spi-dw-pci.o
- obj-$(CONFIG_SPI_EP93XX) += spi-ep93xx.o
-+obj-$(CONFIG_SPI_AIROHA_EN7523) += spi-en7523.o
- obj-$(CONFIG_SPI_FALCON) += spi-falcon.o
- obj-$(CONFIG_SPI_FSI) += spi-fsi.o
- obj-$(CONFIG_SPI_FSL_CPM) += spi-fsl-cpm.o
---- /dev/null
-+++ b/drivers/spi/spi-en7523.c
-@@ -0,0 +1,313 @@
-+// SPDX-License-Identifier: GPL-2.0
-+
-+#include <linux/module.h>
-+#include <linux/platform_device.h>
-+#include <linux/mod_devicetable.h>
-+#include <linux/spi/spi.h>
-+
-+
-+#define ENSPI_READ_IDLE_EN 0x0004
-+#define ENSPI_MTX_MODE_TOG 0x0014
-+#define ENSPI_RDCTL_FSM 0x0018
-+#define ENSPI_MANUAL_EN 0x0020
-+#define ENSPI_MANUAL_OPFIFO_EMPTY 0x0024
-+#define ENSPI_MANUAL_OPFIFO_WDATA 0x0028
-+#define ENSPI_MANUAL_OPFIFO_FULL 0x002C
-+#define ENSPI_MANUAL_OPFIFO_WR 0x0030
-+#define ENSPI_MANUAL_DFIFO_FULL 0x0034
-+#define ENSPI_MANUAL_DFIFO_WDATA 0x0038
-+#define ENSPI_MANUAL_DFIFO_EMPTY 0x003C
-+#define ENSPI_MANUAL_DFIFO_RD 0x0040
-+#define ENSPI_MANUAL_DFIFO_RDATA 0x0044
-+#define ENSPI_IER 0x0090
-+#define ENSPI_NFI2SPI_EN 0x0130
-+
-+// TODO not in spi block
-+#define ENSPI_CLOCK_DIVIDER ((void __iomem *)0x1fa201c4)
-+
-+#define OP_CSH 0x00
-+#define OP_CSL 0x01
-+#define OP_CK 0x02
-+#define OP_OUTS 0x08
-+#define OP_OUTD 0x09
-+#define OP_OUTQ 0x0A
-+#define OP_INS 0x0C
-+#define OP_INS0 0x0D
-+#define OP_IND 0x0E
-+#define OP_INQ 0x0F
-+#define OP_OS2IS 0x10
-+#define OP_OS2ID 0x11
-+#define OP_OS2IQ 0x12
-+#define OP_OD2IS 0x13
-+#define OP_OD2ID 0x14
-+#define OP_OD2IQ 0x15
-+#define OP_OQ2IS 0x16
-+#define OP_OQ2ID 0x17
-+#define OP_OQ2IQ 0x18
-+#define OP_OSNIS 0x19
-+#define OP_ODNID 0x1A
-+
-+#define MATRIX_MODE_AUTO 1
-+#define CONF_MTX_MODE_AUTO 0
-+#define MANUALEN_AUTO 0
-+#define MATRIX_MODE_MANUAL 0
-+#define CONF_MTX_MODE_MANUAL 9
-+#define MANUALEN_MANUAL 1
-+
-+#define _ENSPI_MAX_XFER 0x1ff
-+
-+#define REG(x) (iobase + x)
-+
-+
-+static void __iomem *iobase;
-+
-+
-+static void opfifo_write(u32 cmd, u32 len)
-+{
-+ u32 tmp = ((cmd & 0x1f) << 9) | (len & 0x1ff);
-+
-+ writel(tmp, REG(ENSPI_MANUAL_OPFIFO_WDATA));
-+
-+ /* Wait for room in OPFIFO */
-+ while (readl(REG(ENSPI_MANUAL_OPFIFO_FULL)))
-+ ;
-+
-+ /* Shift command into OPFIFO */
-+ writel(1, REG(ENSPI_MANUAL_OPFIFO_WR));
-+
-+ /* Wait for command to finish */
-+ while (!readl(REG(ENSPI_MANUAL_OPFIFO_EMPTY)))
-+ ;
-+}
-+
-+static void set_cs(int state)
-+{
-+ if (state)
-+ opfifo_write(OP_CSH, 1);
-+ else
-+ opfifo_write(OP_CSL, 1);
-+}
-+
-+static void manual_begin_cmd(void)
-+{
-+ /* Disable read idle state */
-+ writel(0, REG(ENSPI_READ_IDLE_EN));
-+
-+ /* Wait for FSM to reach idle state */
-+ while (readl(REG(ENSPI_RDCTL_FSM)))
-+ ;
-+
-+ /* Set SPI core to manual mode */
-+ writel(CONF_MTX_MODE_MANUAL, REG(ENSPI_MTX_MODE_TOG));
-+ writel(MANUALEN_MANUAL, REG(ENSPI_MANUAL_EN));
-+}
-+
-+static void manual_end_cmd(void)
-+{
-+ /* Set SPI core to auto mode */
-+ writel(CONF_MTX_MODE_AUTO, REG(ENSPI_MTX_MODE_TOG));
-+ writel(MANUALEN_AUTO, REG(ENSPI_MANUAL_EN));
-+
-+ /* Enable read idle state */
-+ writel(1, REG(ENSPI_READ_IDLE_EN));
-+}
-+
-+static void dfifo_read(u8 *buf, int len)
-+{
-+ int i;
-+
-+ for (i = 0; i < len; i++) {
-+ /* Wait for requested data to show up in DFIFO */
-+ while (readl(REG(ENSPI_MANUAL_DFIFO_EMPTY)))
-+ ;
-+ buf[i] = readl(REG(ENSPI_MANUAL_DFIFO_RDATA));
-+ /* Queue up next byte */
-+ writel(1, REG(ENSPI_MANUAL_DFIFO_RD));
-+ }
-+}
-+
-+static void dfifo_write(const u8 *buf, int len)
-+{
-+ int i;
-+
-+ for (i = 0; i < len; i++) {
-+ /* Wait for room in DFIFO */
-+ while (readl(REG(ENSPI_MANUAL_DFIFO_FULL)))
-+ ;
-+ writel(buf[i], REG(ENSPI_MANUAL_DFIFO_WDATA));
-+ }
-+}
-+
-+#if 0
-+static void set_spi_clock_speed(int freq_mhz)
-+{
-+ u32 tmp, val;
-+
-+ tmp = readl(ENSPI_CLOCK_DIVIDER);
-+ tmp &= 0xffff0000;
-+ writel(tmp, ENSPI_CLOCK_DIVIDER);
-+
-+ val = (400 / (freq_mhz * 2));
-+ tmp |= (val << 8) | 1;
-+ writel(tmp, ENSPI_CLOCK_DIVIDER);
-+}
-+#endif
-+
-+static void init_hw(void)
-+{
-+ /* Disable manual/auto mode clash interrupt */
-+ writel(0, REG(ENSPI_IER));
-+
-+ // TODO via clk framework
-+ // set_spi_clock_speed(50);
-+
-+ /* Disable DMA */
-+ writel(0, REG(ENSPI_NFI2SPI_EN));
-+}
-+
-+static int xfer_read(struct spi_transfer *xfer)
-+{
-+ int opcode;
-+ uint8_t *buf = xfer->rx_buf;
-+
-+ switch (xfer->rx_nbits) {
-+ case SPI_NBITS_SINGLE:
-+ opcode = OP_INS;
-+ break;
-+ case SPI_NBITS_DUAL:
-+ opcode = OP_IND;
-+ break;
-+ case SPI_NBITS_QUAD:
-+ opcode = OP_INQ;
-+ break;
-+ }
-+
-+ opfifo_write(opcode, xfer->len);
-+ dfifo_read(buf, xfer->len);
-+
-+ return xfer->len;
-+}
-+
-+static int xfer_write(struct spi_transfer *xfer, int next_xfer_is_rx)
-+{
-+ int opcode;
-+ const uint8_t *buf = xfer->tx_buf;
-+
-+ if (next_xfer_is_rx) {
-+ /* need to use Ox2Ix opcode to set the core to input afterwards */
-+ switch (xfer->tx_nbits) {
-+ case SPI_NBITS_SINGLE:
-+ opcode = OP_OS2IS;
-+ break;
-+ case SPI_NBITS_DUAL:
-+ opcode = OP_OS2ID;
-+ break;
-+ case SPI_NBITS_QUAD:
-+ opcode = OP_OS2IQ;
-+ break;
-+ }
-+ } else {
-+ switch (xfer->tx_nbits) {
-+ case SPI_NBITS_SINGLE:
-+ opcode = OP_OUTS;
-+ break;
-+ case SPI_NBITS_DUAL:
-+ opcode = OP_OUTD;
-+ break;
-+ case SPI_NBITS_QUAD:
-+ opcode = OP_OUTQ;
-+ break;
-+ }
-+ }
-+
-+ opfifo_write(opcode, xfer->len);
-+ dfifo_write(buf, xfer->len);
-+
-+ return xfer->len;
-+}
-+
-+static size_t max_transfer_size(struct spi_device *spi)
-+{
-+ return _ENSPI_MAX_XFER;
-+}
-+
-+static int transfer_one_message(struct spi_controller *ctrl, struct spi_message *msg)
-+{
-+ struct spi_transfer *xfer;
-+ int next_xfer_is_rx = 0;
-+
-+ manual_begin_cmd();
-+ set_cs(0);
-+ list_for_each_entry(xfer, &msg->transfers, transfer_list) {
-+ if (xfer->tx_buf) {
-+ if (!list_is_last(&xfer->transfer_list, &msg->transfers)
-+ && list_next_entry(xfer, transfer_list)->rx_buf != NULL)
-+ next_xfer_is_rx = 1;
-+ else
-+ next_xfer_is_rx = 0;
-+ msg->actual_length += xfer_write(xfer, next_xfer_is_rx);
-+ } else if (xfer->rx_buf) {
-+ msg->actual_length += xfer_read(xfer);
-+ }
-+ }
-+ set_cs(1);
-+ manual_end_cmd();
-+
-+ msg->status = 0;
-+ spi_finalize_current_message(ctrl);
-+
-+ return 0;
-+}
-+
-+static int spi_probe(struct platform_device *pdev)
-+{
-+ struct spi_controller *ctrl;
-+ int err;
-+
-+ ctrl = devm_spi_alloc_master(&pdev->dev, 0);
-+ if (!ctrl) {
-+ dev_err(&pdev->dev, "Error allocating SPI controller\n");
-+ return -ENOMEM;
-+ }
-+
-+ iobase = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
-+ if (IS_ERR(iobase)) {
-+ dev_err(&pdev->dev, "Could not map SPI register address");
-+ return -ENOMEM;
-+ }
-+
-+ init_hw();
-+
-+ ctrl->dev.of_node = pdev->dev.of_node;
-+ ctrl->flags = SPI_CONTROLLER_HALF_DUPLEX;
-+ ctrl->mode_bits = SPI_RX_DUAL | SPI_TX_DUAL;
-+ ctrl->max_transfer_size = max_transfer_size;
-+ ctrl->transfer_one_message = transfer_one_message;
-+ err = devm_spi_register_controller(&pdev->dev, ctrl);
-+ if (err) {
-+ dev_err(&pdev->dev, "Could not register SPI controller\n");
-+ return -ENODEV;
-+ }
-+
-+ return 0;
-+}
-+
-+static const struct of_device_id spi_of_ids[] = {
-+ { .compatible = "airoha,en7523-spi" },
-+ { /* sentinel */ }
-+};
-+MODULE_DEVICE_TABLE(of, spi_of_ids);
-+
-+static struct platform_driver spi_driver = {
-+ .probe = spi_probe,
-+ .driver = {
-+ .name = "airoha-en7523-spi",
-+ .of_match_table = spi_of_ids,
-+ },
-+};
-+
-+module_platform_driver(spi_driver);
-+
-+MODULE_LICENSE("GPL v2");
-+MODULE_AUTHOR("Bert Vermeulen <bert@biot.com>");
-+MODULE_DESCRIPTION("Airoha EN7523 SPI driver");