--- /dev/null
+/*
+ * Intel PCH/PCU SPI flash driver.
+ *
+ * Copyright (C) 2016, Intel Corporation
+ * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/sizes.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mtd/spi-nor.h>
+#include <linux/platform_data/intel-spi.h>
+
+#include "intel-spi.h"
+
+/* Offsets are from @ispi->base */
+#define BFPREG 0x00
+
+#define HSFSTS_CTL 0x04
+#define HSFSTS_CTL_FSMIE BIT(31)
+#define HSFSTS_CTL_FDBC_SHIFT 24
+#define HSFSTS_CTL_FDBC_MASK (0x3f << HSFSTS_CTL_FDBC_SHIFT)
+
+#define HSFSTS_CTL_FCYCLE_SHIFT 17
+#define HSFSTS_CTL_FCYCLE_MASK (0x0f << HSFSTS_CTL_FCYCLE_SHIFT)
+/* HW sequencer opcodes */
+#define HSFSTS_CTL_FCYCLE_READ (0x00 << HSFSTS_CTL_FCYCLE_SHIFT)
+#define HSFSTS_CTL_FCYCLE_WRITE (0x02 << HSFSTS_CTL_FCYCLE_SHIFT)
+#define HSFSTS_CTL_FCYCLE_ERASE (0x03 << HSFSTS_CTL_FCYCLE_SHIFT)
+#define HSFSTS_CTL_FCYCLE_ERASE_64K (0x04 << HSFSTS_CTL_FCYCLE_SHIFT)
+#define HSFSTS_CTL_FCYCLE_RDID (0x06 << HSFSTS_CTL_FCYCLE_SHIFT)
+#define HSFSTS_CTL_FCYCLE_WRSR (0x07 << HSFSTS_CTL_FCYCLE_SHIFT)
+#define HSFSTS_CTL_FCYCLE_RDSR (0x08 << HSFSTS_CTL_FCYCLE_SHIFT)
+
+#define HSFSTS_CTL_FGO BIT(16)
+#define HSFSTS_CTL_FLOCKDN BIT(15)
+#define HSFSTS_CTL_FDV BIT(14)
+#define HSFSTS_CTL_SCIP BIT(5)
+#define HSFSTS_CTL_AEL BIT(2)
+#define HSFSTS_CTL_FCERR BIT(1)
+#define HSFSTS_CTL_FDONE BIT(0)
+
+#define FADDR 0x08
+#define DLOCK 0x0c
+#define FDATA(n) (0x10 + ((n) * 4))
+
+#define FRACC 0x50
+
+#define FREG(n) (0x54 + ((n) * 4))
+#define FREG_BASE_MASK 0x3fff
+#define FREG_LIMIT_SHIFT 16
+#define FREG_LIMIT_MASK (0x03fff << FREG_LIMIT_SHIFT)
+
+/* Offset is from @ispi->pregs */
+#define PR(n) ((n) * 4)
+#define PR_WPE BIT(31)
+#define PR_LIMIT_SHIFT 16
+#define PR_LIMIT_MASK (0x3fff << PR_LIMIT_SHIFT)
+#define PR_RPE BIT(15)
+#define PR_BASE_MASK 0x3fff
+/* Last PR is GPR0 */
+#define PR_NUM (5 + 1)
+
+/* Offsets are from @ispi->sregs */
+#define SSFSTS_CTL 0x00
+#define SSFSTS_CTL_FSMIE BIT(23)
+#define SSFSTS_CTL_DS BIT(22)
+#define SSFSTS_CTL_DBC_SHIFT 16
+#define SSFSTS_CTL_SPOP BIT(11)
+#define SSFSTS_CTL_ACS BIT(10)
+#define SSFSTS_CTL_SCGO BIT(9)
+#define SSFSTS_CTL_COP_SHIFT 12
+#define SSFSTS_CTL_FRS BIT(7)
+#define SSFSTS_CTL_DOFRS BIT(6)
+#define SSFSTS_CTL_AEL BIT(4)
+#define SSFSTS_CTL_FCERR BIT(3)
+#define SSFSTS_CTL_FDONE BIT(2)
+#define SSFSTS_CTL_SCIP BIT(0)
+
+#define PREOP_OPTYPE 0x04
+#define OPMENU0 0x08
+#define OPMENU1 0x0c
+
+/* CPU specifics */
+#define BYT_PR 0x74
+#define BYT_SSFSTS_CTL 0x90
+#define BYT_BCR 0xfc
+#define BYT_BCR_WPD BIT(0)
+#define BYT_FREG_NUM 5
+
+#define LPT_PR 0x74
+#define LPT_SSFSTS_CTL 0x90
+#define LPT_FREG_NUM 5
+
+#define BXT_PR 0x84
+#define BXT_SSFSTS_CTL 0xa0
+#define BXT_FREG_NUM 12
+
+#define INTEL_SPI_TIMEOUT 5000 /* ms */
+#define INTEL_SPI_FIFO_SZ 64
+
+/**
+ * struct intel_spi - Driver private data
+ * @dev: Device pointer
+ * @info: Pointer to board specific info
+ * @nor: SPI NOR layer structure
+ * @base: Beginning of MMIO space
+ * @pregs: Start of protection registers
+ * @sregs: Start of software sequencer registers
+ * @nregions: Maximum number of regions
+ * @writeable: Is the chip writeable
+ * @swseq: Use SW sequencer in register reads/writes
+ * @erase_64k: 64k erase supported
+ * @opcodes: Opcodes which are supported. This are programmed by BIOS
+ * before it locks down the controller.
+ * @preopcodes: Preopcodes which are supported.
+ */
+struct intel_spi {
+ struct device *dev;
+ const struct intel_spi_boardinfo *info;
+ struct spi_nor nor;
+ void __iomem *base;
+ void __iomem *pregs;
+ void __iomem *sregs;
+ size_t nregions;
+ bool writeable;
+ bool swseq;
+ bool erase_64k;
+ u8 opcodes[8];
+ u8 preopcodes[2];
+};
+
+static bool writeable;
+module_param(writeable, bool, 0);
+MODULE_PARM_DESC(writeable, "Enable write access to SPI flash chip (default=0)");
+
+static void intel_spi_dump_regs(struct intel_spi *ispi)
+{
+ u32 value;
+ int i;
+
+ dev_dbg(ispi->dev, "BFPREG=0x%08x\n", readl(ispi->base + BFPREG));
+
+ value = readl(ispi->base + HSFSTS_CTL);
+ dev_dbg(ispi->dev, "HSFSTS_CTL=0x%08x\n", value);
+ if (value & HSFSTS_CTL_FLOCKDN)
+ dev_dbg(ispi->dev, "-> Locked\n");
+
+ dev_dbg(ispi->dev, "FADDR=0x%08x\n", readl(ispi->base + FADDR));
+ dev_dbg(ispi->dev, "DLOCK=0x%08x\n", readl(ispi->base + DLOCK));
+
+ for (i = 0; i < 16; i++)
+ dev_dbg(ispi->dev, "FDATA(%d)=0x%08x\n",
+ i, readl(ispi->base + FDATA(i)));
+
+ dev_dbg(ispi->dev, "FRACC=0x%08x\n", readl(ispi->base + FRACC));
+
+ for (i = 0; i < ispi->nregions; i++)
+ dev_dbg(ispi->dev, "FREG(%d)=0x%08x\n", i,
+ readl(ispi->base + FREG(i)));
+ for (i = 0; i < PR_NUM; i++)
+ dev_dbg(ispi->dev, "PR(%d)=0x%08x\n", i,
+ readl(ispi->pregs + PR(i)));
+
+ value = readl(ispi->sregs + SSFSTS_CTL);
+ dev_dbg(ispi->dev, "SSFSTS_CTL=0x%08x\n", value);
+ dev_dbg(ispi->dev, "PREOP_OPTYPE=0x%08x\n",
+ readl(ispi->sregs + PREOP_OPTYPE));
+ dev_dbg(ispi->dev, "OPMENU0=0x%08x\n", readl(ispi->sregs + OPMENU0));
+ dev_dbg(ispi->dev, "OPMENU1=0x%08x\n", readl(ispi->sregs + OPMENU1));
+
+ if (ispi->info->type == INTEL_SPI_BYT)
+ dev_dbg(ispi->dev, "BCR=0x%08x\n", readl(ispi->base + BYT_BCR));
+
+ dev_dbg(ispi->dev, "Protected regions:\n");
+ for (i = 0; i < PR_NUM; i++) {
+ u32 base, limit;
+
+ value = readl(ispi->pregs + PR(i));
+ if (!(value & (PR_WPE | PR_RPE)))
+ continue;
+
+ limit = (value & PR_LIMIT_MASK) >> PR_LIMIT_SHIFT;
+ base = value & PR_BASE_MASK;
+
+ dev_dbg(ispi->dev, " %02d base: 0x%08x limit: 0x%08x [%c%c]\n",
+ i, base << 12, (limit << 12) | 0xfff,
+ value & PR_WPE ? 'W' : '.',
+ value & PR_RPE ? 'R' : '.');
+ }
+
+ dev_dbg(ispi->dev, "Flash regions:\n");
+ for (i = 0; i < ispi->nregions; i++) {
+ u32 region, base, limit;
+
+ region = readl(ispi->base + FREG(i));
+ base = region & FREG_BASE_MASK;
+ limit = (region & FREG_LIMIT_MASK) >> FREG_LIMIT_SHIFT;
+
+ if (base >= limit || (i > 0 && limit == 0))
+ dev_dbg(ispi->dev, " %02d disabled\n", i);
+ else
+ dev_dbg(ispi->dev, " %02d base: 0x%08x limit: 0x%08x\n",
+ i, base << 12, (limit << 12) | 0xfff);
+ }
+
+ dev_dbg(ispi->dev, "Using %cW sequencer for register access\n",
+ ispi->swseq ? 'S' : 'H');
+}
+
+/* Reads max INTEL_SPI_FIFO_SZ bytes from the device fifo */
+static int intel_spi_read_block(struct intel_spi *ispi, void *buf, size_t size)
+{
+ size_t bytes;
+ int i = 0;
+
+ if (size > INTEL_SPI_FIFO_SZ)
+ return -EINVAL;
+
+ while (size > 0) {
+ bytes = min_t(size_t, size, 4);
+ memcpy_fromio(buf, ispi->base + FDATA(i), bytes);
+ size -= bytes;
+ buf += bytes;
+ i++;
+ }
+
+ return 0;
+}
+
+/* Writes max INTEL_SPI_FIFO_SZ bytes to the device fifo */
+static int intel_spi_write_block(struct intel_spi *ispi, const void *buf,
+ size_t size)
+{
+ size_t bytes;
+ int i = 0;
+
+ if (size > INTEL_SPI_FIFO_SZ)
+ return -EINVAL;
+
+ while (size > 0) {
+ bytes = min_t(size_t, size, 4);
+ memcpy_toio(ispi->base + FDATA(i), buf, bytes);
+ size -= bytes;
+ buf += bytes;
+ i++;
+ }
+
+ return 0;
+}
+
+static int intel_spi_wait_hw_busy(struct intel_spi *ispi)
+{
+ u32 val;
+
+ return readl_poll_timeout(ispi->base + HSFSTS_CTL, val,
+ !(val & HSFSTS_CTL_SCIP), 0,
+ INTEL_SPI_TIMEOUT * 1000);
+}
+
+static int intel_spi_wait_sw_busy(struct intel_spi *ispi)
+{
+ u32 val;
+
+ return readl_poll_timeout(ispi->sregs + SSFSTS_CTL, val,
+ !(val & SSFSTS_CTL_SCIP), 0,
+ INTEL_SPI_TIMEOUT * 1000);
+}
+
+static int intel_spi_init(struct intel_spi *ispi)
+{
+ u32 opmenu0, opmenu1, val;
+ int i;
+
+ switch (ispi->info->type) {
+ case INTEL_SPI_BYT:
+ ispi->sregs = ispi->base + BYT_SSFSTS_CTL;
+ ispi->pregs = ispi->base + BYT_PR;
+ ispi->nregions = BYT_FREG_NUM;
+
+ if (writeable) {
+ /* Disable write protection */
+ val = readl(ispi->base + BYT_BCR);
+ if (!(val & BYT_BCR_WPD)) {
+ val |= BYT_BCR_WPD;
+ writel(val, ispi->base + BYT_BCR);
+ val = readl(ispi->base + BYT_BCR);
+ }
+
+ ispi->writeable = !!(val & BYT_BCR_WPD);
+ }
+
+ break;
+
+ case INTEL_SPI_LPT:
+ ispi->sregs = ispi->base + LPT_SSFSTS_CTL;
+ ispi->pregs = ispi->base + LPT_PR;
+ ispi->nregions = LPT_FREG_NUM;
+ break;
+
+ case INTEL_SPI_BXT:
+ ispi->sregs = ispi->base + BXT_SSFSTS_CTL;
+ ispi->pregs = ispi->base + BXT_PR;
+ ispi->nregions = BXT_FREG_NUM;
+ ispi->erase_64k = true;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ /* Disable #SMI generation */
+ val = readl(ispi->base + HSFSTS_CTL);
+ val &= ~HSFSTS_CTL_FSMIE;
+ writel(val, ispi->base + HSFSTS_CTL);
+
+ /*
+ * BIOS programs allowed opcodes and then locks down the register.
+ * So read back what opcodes it decided to support. That's the set
+ * we are going to support as well.
+ */
+ opmenu0 = readl(ispi->sregs + OPMENU0);
+ opmenu1 = readl(ispi->sregs + OPMENU1);
+
+ /*
+ * Some controllers can only do basic operations using hardware
+ * sequencer. All other operations are supposed to be carried out
+ * using software sequencer. If we find that BIOS has programmed
+ * opcodes for the software sequencer we use that over the hardware
+ * sequencer.
+ */
+ if (opmenu0 && opmenu1) {
+ for (i = 0; i < ARRAY_SIZE(ispi->opcodes) / 2; i++) {
+ ispi->opcodes[i] = opmenu0 >> i * 8;
+ ispi->opcodes[i + 4] = opmenu1 >> i * 8;
+ }
+
+ val = readl(ispi->sregs + PREOP_OPTYPE);
+ ispi->preopcodes[0] = val;
+ ispi->preopcodes[1] = val >> 8;
+
+ /* Disable #SMI generation from SW sequencer */
+ val = readl(ispi->sregs + SSFSTS_CTL);
+ val &= ~SSFSTS_CTL_FSMIE;
+ writel(val, ispi->sregs + SSFSTS_CTL);
+
+ ispi->swseq = true;
+ }
+
+ intel_spi_dump_regs(ispi);
+
+ return 0;
+}
+
+static int intel_spi_opcode_index(struct intel_spi *ispi, u8 opcode)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(ispi->opcodes); i++)
+ if (ispi->opcodes[i] == opcode)
+ return i;
+ return -EINVAL;
+}
+
+static int intel_spi_hw_cycle(struct intel_spi *ispi, u8 opcode, u8 *buf,
+ int len)
+{
+ u32 val, status;
+ int ret;
+
+ val = readl(ispi->base + HSFSTS_CTL);
+ val &= ~(HSFSTS_CTL_FCYCLE_MASK | HSFSTS_CTL_FDBC_MASK);
+
+ switch (opcode) {
+ case SPINOR_OP_RDID:
+ val |= HSFSTS_CTL_FCYCLE_RDID;
+ break;
+ case SPINOR_OP_WRSR:
+ val |= HSFSTS_CTL_FCYCLE_WRSR;
+ break;
+ case SPINOR_OP_RDSR:
+ val |= HSFSTS_CTL_FCYCLE_RDSR;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ val |= (len - 1) << HSFSTS_CTL_FDBC_SHIFT;
+ val |= HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
+ val |= HSFSTS_CTL_FGO;
+ writel(val, ispi->base + HSFSTS_CTL);
+
+ ret = intel_spi_wait_hw_busy(ispi);
+ if (ret)
+ return ret;
+
+ status = readl(ispi->base + HSFSTS_CTL);
+ if (status & HSFSTS_CTL_FCERR)
+ return -EIO;
+ else if (status & HSFSTS_CTL_AEL)
+ return -EACCES;
+
+ return 0;
+}
+
+static int intel_spi_sw_cycle(struct intel_spi *ispi, u8 opcode, u8 *buf,
+ int len)
+{
+ u32 val, status;
+ int ret;
+
+ ret = intel_spi_opcode_index(ispi, opcode);
+ if (ret < 0)
+ return ret;
+
+ val = (len << SSFSTS_CTL_DBC_SHIFT) | SSFSTS_CTL_DS;
+ val |= ret << SSFSTS_CTL_COP_SHIFT;
+ val |= SSFSTS_CTL_FCERR | SSFSTS_CTL_FDONE;
+ val |= SSFSTS_CTL_SCGO;
+ writel(val, ispi->sregs + SSFSTS_CTL);
+
+ ret = intel_spi_wait_sw_busy(ispi);
+ if (ret)
+ return ret;
+
+ status = readl(ispi->base + SSFSTS_CTL);
+ if (status & SSFSTS_CTL_FCERR)
+ return -EIO;
+ else if (status & SSFSTS_CTL_AEL)
+ return -EACCES;
+
+ return 0;
+}
+
+static int intel_spi_read_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
+{
+ struct intel_spi *ispi = nor->priv;
+ int ret;
+
+ /* Address of the first chip */
+ writel(0, ispi->base + FADDR);
+
+ if (ispi->swseq)
+ ret = intel_spi_sw_cycle(ispi, opcode, buf, len);
+ else
+ ret = intel_spi_hw_cycle(ispi, opcode, buf, len);
+
+ if (ret)
+ return ret;
+
+ return intel_spi_read_block(ispi, buf, len);
+}
+
+static int intel_spi_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
+{
+ struct intel_spi *ispi = nor->priv;
+ int ret;
+
+ /*
+ * This is handled with atomic operation and preop code in Intel
+ * controller so skip it here now.
+ */
+ if (opcode == SPINOR_OP_WREN)
+ return 0;
+
+ writel(0, ispi->base + FADDR);
+
+ /* Write the value beforehand */
+ ret = intel_spi_write_block(ispi, buf, len);
+ if (ret)
+ return ret;
+
+ if (ispi->swseq)
+ return intel_spi_sw_cycle(ispi, opcode, buf, len);
+ return intel_spi_hw_cycle(ispi, opcode, buf, len);
+}
+
+static ssize_t intel_spi_read(struct spi_nor *nor, loff_t from, size_t len,
+ u_char *read_buf)
+{
+ struct intel_spi *ispi = nor->priv;
+ size_t block_size, retlen = 0;
+ u32 val, status;
+ ssize_t ret;
+
+ switch (nor->read_opcode) {
+ case SPINOR_OP_READ:
+ case SPINOR_OP_READ_FAST:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ while (len > 0) {
+ block_size = min_t(size_t, len, INTEL_SPI_FIFO_SZ);
+
+ writel(from, ispi->base + FADDR);
+
+ val = readl(ispi->base + HSFSTS_CTL);
+ val &= ~(HSFSTS_CTL_FDBC_MASK | HSFSTS_CTL_FCYCLE_MASK);
+ val |= HSFSTS_CTL_AEL | HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
+ val |= (block_size - 1) << HSFSTS_CTL_FDBC_SHIFT;
+ val |= HSFSTS_CTL_FCYCLE_READ;
+ val |= HSFSTS_CTL_FGO;
+ writel(val, ispi->base + HSFSTS_CTL);
+
+ ret = intel_spi_wait_hw_busy(ispi);
+ if (ret)
+ return ret;
+
+ status = readl(ispi->base + HSFSTS_CTL);
+ if (status & HSFSTS_CTL_FCERR)
+ ret = -EIO;
+ else if (status & HSFSTS_CTL_AEL)
+ ret = -EACCES;
+
+ if (ret < 0) {
+ dev_err(ispi->dev, "read error: %llx: %#x\n", from,
+ status);
+ return ret;
+ }
+
+ ret = intel_spi_read_block(ispi, read_buf, block_size);
+ if (ret)
+ return ret;
+
+ len -= block_size;
+ from += block_size;
+ retlen += block_size;
+ read_buf += block_size;
+ }
+
+ return retlen;
+}
+
+static ssize_t intel_spi_write(struct spi_nor *nor, loff_t to, size_t len,
+ const u_char *write_buf)
+{
+ struct intel_spi *ispi = nor->priv;
+ size_t block_size, retlen = 0;
+ u32 val, status;
+ ssize_t ret;
+
+ while (len > 0) {
+ block_size = min_t(size_t, len, INTEL_SPI_FIFO_SZ);
+
+ writel(to, ispi->base + FADDR);
+
+ val = readl(ispi->base + HSFSTS_CTL);
+ val &= ~(HSFSTS_CTL_FDBC_MASK | HSFSTS_CTL_FCYCLE_MASK);
+ val |= HSFSTS_CTL_AEL | HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
+ val |= (block_size - 1) << HSFSTS_CTL_FDBC_SHIFT;
+ val |= HSFSTS_CTL_FCYCLE_WRITE;
+
+ /* Write enable */
+ if (ispi->preopcodes[1] == SPINOR_OP_WREN)
+ val |= SSFSTS_CTL_SPOP;
+ val |= SSFSTS_CTL_ACS;
+ writel(val, ispi->base + HSFSTS_CTL);
+
+ ret = intel_spi_write_block(ispi, write_buf, block_size);
+ if (ret) {
+ dev_err(ispi->dev, "failed to write block\n");
+ return ret;
+ }
+
+ /* Start the write now */
+ val = readl(ispi->base + HSFSTS_CTL);
+ writel(val | HSFSTS_CTL_FGO, ispi->base + HSFSTS_CTL);
+
+ ret = intel_spi_wait_hw_busy(ispi);
+ if (ret) {
+ dev_err(ispi->dev, "timeout\n");
+ return ret;
+ }
+
+ status = readl(ispi->base + HSFSTS_CTL);
+ if (status & HSFSTS_CTL_FCERR)
+ ret = -EIO;
+ else if (status & HSFSTS_CTL_AEL)
+ ret = -EACCES;
+
+ if (ret < 0) {
+ dev_err(ispi->dev, "write error: %llx: %#x\n", to,
+ status);
+ return ret;
+ }
+
+ len -= block_size;
+ to += block_size;
+ retlen += block_size;
+ write_buf += block_size;
+ }
+
+ return retlen;
+}
+
+static int intel_spi_erase(struct spi_nor *nor, loff_t offs)
+{
+ size_t erase_size, len = nor->mtd.erasesize;
+ struct intel_spi *ispi = nor->priv;
+ u32 val, status, cmd;
+ int ret;
+
+ /* If the hardware can do 64k erase use that when possible */
+ if (len >= SZ_64K && ispi->erase_64k) {
+ cmd = HSFSTS_CTL_FCYCLE_ERASE_64K;
+ erase_size = SZ_64K;
+ } else {
+ cmd = HSFSTS_CTL_FCYCLE_ERASE;
+ erase_size = SZ_4K;
+ }
+
+ while (len > 0) {
+ writel(offs, ispi->base + FADDR);
+
+ val = readl(ispi->base + HSFSTS_CTL);
+ val &= ~(HSFSTS_CTL_FDBC_MASK | HSFSTS_CTL_FCYCLE_MASK);
+ val |= HSFSTS_CTL_AEL | HSFSTS_CTL_FCERR | HSFSTS_CTL_FDONE;
+ val |= cmd;
+ val |= HSFSTS_CTL_FGO;
+ writel(val, ispi->base + HSFSTS_CTL);
+
+ ret = intel_spi_wait_hw_busy(ispi);
+ if (ret)
+ return ret;
+
+ status = readl(ispi->base + HSFSTS_CTL);
+ if (status & HSFSTS_CTL_FCERR)
+ return -EIO;
+ else if (status & HSFSTS_CTL_AEL)
+ return -EACCES;
+
+ offs += erase_size;
+ len -= erase_size;
+ }
+
+ return 0;
+}
+
+static bool intel_spi_is_protected(const struct intel_spi *ispi,
+ unsigned int base, unsigned int limit)
+{
+ int i;
+
+ for (i = 0; i < PR_NUM; i++) {
+ u32 pr_base, pr_limit, pr_value;
+
+ pr_value = readl(ispi->pregs + PR(i));
+ if (!(pr_value & (PR_WPE | PR_RPE)))
+ continue;
+
+ pr_limit = (pr_value & PR_LIMIT_MASK) >> PR_LIMIT_SHIFT;
+ pr_base = pr_value & PR_BASE_MASK;
+
+ if (pr_base >= base && pr_limit <= limit)
+ return true;
+ }
+
+ return false;
+}
+
+/*
+ * There will be a single partition holding all enabled flash regions. We
+ * call this "BIOS".
+ */
+static void intel_spi_fill_partition(struct intel_spi *ispi,
+ struct mtd_partition *part)
+{
+ u64 end;
+ int i;
+
+ memset(part, 0, sizeof(*part));
+
+ /* Start from the mandatory descriptor region */
+ part->size = 4096;
+ part->name = "BIOS";
+
+ /*
+ * Now try to find where this partition ends based on the flash
+ * region registers.
+ */
+ for (i = 1; i < ispi->nregions; i++) {
+ u32 region, base, limit;
+
+ region = readl(ispi->base + FREG(i));
+ base = region & FREG_BASE_MASK;
+ limit = (region & FREG_LIMIT_MASK) >> FREG_LIMIT_SHIFT;
+
+ if (base >= limit || limit == 0)
+ continue;
+
+ /*
+ * If any of the regions have protection bits set, make the
+ * whole partition read-only to be on the safe side.
+ */
+ if (intel_spi_is_protected(ispi, base, limit))
+ ispi->writeable = 0;
+
+ end = (limit << 12) + 4096;
+ if (end > part->size)
+ part->size = end;
+ }
+}
+
+struct intel_spi *intel_spi_probe(struct device *dev,
+ struct resource *mem, const struct intel_spi_boardinfo *info)
+{
+ struct mtd_partition part;
+ struct intel_spi *ispi;
+ int ret;
+
+ if (!info || !mem)
+ return ERR_PTR(-EINVAL);
+
+ ispi = devm_kzalloc(dev, sizeof(*ispi), GFP_KERNEL);
+ if (!ispi)
+ return ERR_PTR(-ENOMEM);
+
+ ispi->base = devm_ioremap_resource(dev, mem);
+ if (IS_ERR(ispi->base))
+ return ispi->base;
+
+ ispi->dev = dev;
+ ispi->info = info;
+ ispi->writeable = info->writeable;
+
+ ret = intel_spi_init(ispi);
+ if (ret)
+ return ERR_PTR(ret);
+
+ ispi->nor.dev = ispi->dev;
+ ispi->nor.priv = ispi;
+ ispi->nor.read_reg = intel_spi_read_reg;
+ ispi->nor.write_reg = intel_spi_write_reg;
+ ispi->nor.read = intel_spi_read;
+ ispi->nor.write = intel_spi_write;
+ ispi->nor.erase = intel_spi_erase;
+
+ ret = spi_nor_scan(&ispi->nor, NULL, SPI_NOR_NORMAL);
+ if (ret) {
+ dev_info(dev, "failed to locate the chip\n");
+ return ERR_PTR(ret);
+ }
+
+ intel_spi_fill_partition(ispi, &part);
+
+ /* Prevent writes if not explicitly enabled */
+ if (!ispi->writeable || !writeable)
+ ispi->nor.mtd.flags &= ~MTD_WRITEABLE;
+
+ ret = mtd_device_parse_register(&ispi->nor.mtd, NULL, NULL, &part, 1);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return ispi;
+}
+EXPORT_SYMBOL_GPL(intel_spi_probe);
+
+int intel_spi_remove(struct intel_spi *ispi)
+{
+ return mtd_device_unregister(&ispi->nor.mtd);
+}
+EXPORT_SYMBOL_GPL(intel_spi_remove);
+
+MODULE_DESCRIPTION("Intel PCH/PCU SPI flash core driver");
+MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
+MODULE_LICENSE("GPL v2");
projects / GitHub / LineageOS / android_kernel_motorola_exynos9610.git / commitdiff