Re: [PATCH 2/3] mtd: spi-nor: core code for the Altera Quadspi Flash Controller v2

From: Marek Vasut
Date: Tue Jun 27 2017 - 06:21:07 EST


On 06/26/2017 06:13 PM, matthew.gerlach@xxxxxxxxxxxxxxx wrote:
> From: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>
>
> Signed-off-by: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>
> ---
> MAINTAINERS | 7 +
> drivers/mtd/spi-nor/Kconfig | 5 +
> drivers/mtd/spi-nor/Makefile | 4 +-
> drivers/mtd/spi-nor/altera-quadspi.c | 676 +++++++++++++++++++++++++++++++++++
> include/linux/mtd/altera-quadspi.h | 28 ++
> 5 files changed, 719 insertions(+), 1 deletion(-)
> create mode 100644 drivers/mtd/spi-nor/altera-quadspi.c
> create mode 100644 include/linux/mtd/altera-quadspi.h
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 6b4395c..ae33fa6 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -648,6 +648,13 @@ L: linux-gpio@xxxxxxxxxxxxxxx
> S: Maintained
> F: drivers/gpio/gpio-altera.c
>
> +ALTERA QUADSPI FLASH DRIVER
> +M: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>
> +L: linux-mtd@xxxxxxxxxxxxxxxxxxx
> +S: Maintained
> +F: drivers/mtd/spi-nor/altera-quadspi.c
> +F: inclulde/linux/mtd/altera-quadspi.h
> +
> ALTERA SYSTEM RESOURCE DRIVER FOR ARRIA10 DEVKIT
> M: Thor Thayer <thor.thayer@xxxxxxxxxxxxxxx>
> S: Maintained
> diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig
> index 293c8a4..89fe425 100644
> --- a/drivers/mtd/spi-nor/Kconfig
> +++ b/drivers/mtd/spi-nor/Kconfig
> @@ -113,4 +113,9 @@ config SPI_STM32_QUADSPI
> This enables support for the STM32 Quad SPI controller.
> We only connect the NOR to this controller.
>
> +config SPI_ALTERA_QUADSPI
> + tristate "Altera Quad SPI Flash Controller II"
> + help
> + Enable support for version 2 of Altera Quad SPI Flash Controller.

Some more description would be useful.

> endif # MTD_SPI_NOR
> diff --git a/drivers/mtd/spi-nor/Makefile b/drivers/mtd/spi-nor/Makefile
> index 285aab8..024c6ac 100644
> --- a/drivers/mtd/spi-nor/Makefile
> +++ b/drivers/mtd/spi-nor/Makefile
> @@ -8,4 +8,6 @@ obj-$(CONFIG_MTD_MT81xx_NOR) += mtk-quadspi.o
> obj-$(CONFIG_SPI_NXP_SPIFI) += nxp-spifi.o
> obj-$(CONFIG_SPI_INTEL_SPI) += intel-spi.o
> obj-$(CONFIG_SPI_INTEL_SPI_PLATFORM) += intel-spi-platform.o
> -obj-$(CONFIG_SPI_STM32_QUADSPI) += stm32-quadspi.o
> \ No newline at end of file
> +obj-$(CONFIG_SPI_STM32_QUADSPI) += stm32-quadspi.o
> +obj-$(CONFIG_SPI_ALTERA_QUADSPI) += altera-quadspi.o

Keep the list sorted

> diff --git a/drivers/mtd/spi-nor/altera-quadspi.c b/drivers/mtd/spi-nor/altera-quadspi.c
> new file mode 100644
> index 0000000..de65453
> --- /dev/null
> +++ b/drivers/mtd/spi-nor/altera-quadspi.c
> @@ -0,0 +1,676 @@
> +/*
> + * Copyright (C) 2014 Altera Corporation. All rights reserved.
> + * Copyright (C) 2017 Intel Corporation. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +

One newline too many

> +#include <linux/bitrev.h>
> +#include <linux/module.h>
> +#include <linux/mtd/altera-quadspi.h>
> +#include <linux/mtd/mtd.h>
> +#include <linux/mtd/spi-nor.h>
> +
> +#define ALTERA_QUADSPI_RESOURCE_NAME "altera_quadspi"
> +
> +#define EPCS_OPCODE_ID 1
> +#define NON_EPCS_OPCODE_ID 2
> +
> +#define WRITE_CHECK 1
> +#define ERASE_CHECK 0
> +
> +#define QUADSPI_SR_REG 0x0
> +#define QUADSPI_SR_MASK 0x0000000F
> +
> +/* defines for device id register */
> +#define QUADSPI_SID_REG 0x4
> +#define QUADSPI_RDID_REG 0x8
> +#define QUADSPI_ID_MASK 0x000000FF
> +
> +/*
> + * QUADSPI_MEM_OP register offset
> + *
> + * The QUADSPI_MEM_OP register is used to do memory protect and erase operations
> + *
> + */
> +#define QUADSPI_MEM_OP_REG 0xC
> +
> +#define QUADSPI_MEM_OP_CMD_MASK 0x00000003
> +#define QUADSPI_MEM_OP_BULK_ERASE_CMD 0x00000001
> +#define QUADSPI_MEM_OP_SECTOR_ERASE_CMD 0x00000002
> +#define QUADSPI_MEM_OP_SECTOR_PROTECT_CMD 0x00000003
> +#define QUADSPI_MEM_OP_SECTOR_WRITE_ENABLE_CMD 0x00000004
> +#define QUADSPI_MEM_OP_SECTOR_VALUE_MASK 0x0003FF00
> +
> +#define QUADSPI_MEM_OP_SECTOR_PROTECT_SHIFT 8
> +#define QUADSPI_MEM_OP_SECTOR_PROTECT_VALUE_MASK 0x00001F00
> +/*
> + * QUADSPI_ISR register offset
> + *
> + * The QUADSPI_ISR register is used to determine whether an invalid write or
> + * erase operation trigerred an interrupt
> + *
> + */
> +#define QUADSPI_ISR_REG 0x10
> +
> +#define QUADSPI_ISR_ILLEGAL_ERASE_MASK 0x00000001
> +#define QUADSPI_ISR_ILLEGAL_WRITE_MASK 0x00000002
> +
> +/*
> + * QUADSPI_IMR register offset
> + *
> + * The QUADSPI_IMR register is used to mask the invalid erase or the invalid
> + * write interrupts.
> + *
> + */
> +#define QUADSPI_IMR_REG 0x14
> +#define QUADSPI_IMR_ILLEGAL_ERASE_MASK 0x00000001
> +
> +#define QUADSPI_IMR_ILLEGAL_WRITE_MASK 0x00000002
> +
> +#define QUADSPI_CHIP_SELECT_REG 0x18
> +#define QUADSPI_CHIP_SELECT_MASK 0x00000007
> +#define QUADSPI_CHIP_SELECT_0 0x00000001
> +#define QUADSPI_CHIP_SELECT_1 0x00000002
> +#define QUADSPI_CHIP_SELECT_2 0x00000004

BIT() ?

> +#define QUADSPI_FLAG_STATUS_REG 0x1C
> +#define QUADSPI_DEV_ID_DATA_0 0x20
> +#define QUADSPI_DEV_ID_DATA_1 0x24
> +#define QUADSPI_DEV_ID_DATA_2 0x28
> +#define QUADSPI_DEV_ID_DATA_3 0x2C
> +#define QUADSPI_DEV_ID_DATA_4 0x30
> +
> +#define QUADSPI_WIN_OCC_REG 0x4
> +#define QUADSPI_WIN_OCC_SFT 24
> +
> +#define QUADSPI_WIN_SEL_REG 0x8
> +
> +struct altera_quadspi {
> + u32 opcode_id;
> + void __iomem *csr_base;
> + void __iomem *data_base;
> + void __iomem *window_base;
> + size_t window_size;
> + u32 num_flashes;
> + u32 flags;
> + struct device *dev;
> + struct altera_quadspi_flash *flash[ALTERA_QUADSPI_MAX_NUM_FLASH_CHIP];
> + struct device_node *np[ALTERA_QUADSPI_MAX_NUM_FLASH_CHIP];

Is this np even necessary ? Or why don't you put it into
altera_quadspi_flash {} ?

> +};
> +
> +struct altera_quadspi_flash {
> + struct spi_nor nor;
> + struct altera_quadspi *q;
> + u32 bank;
> +};
> +
> +struct flash_device {
> + char *name;
> + u32 opcode_id;
> + u32 device_id;
> +};
> +
> +#ifdef DEBUG

Yet another magic NIH readl/writel debug ... sigh, drop it.

> +static inline u32 alt_qspi_readl(void __iomem *base, off_t offset)
> +{
> + u32 val = readl(base + offset);
> +
> + pr_info("%s 0x%x from offset 0x%lx\n", __func__, val, offset);
> + return val;
> +}
> +static inline void alt_qspi_writel(u32 val, void __iomem *base, off_t offset)
> +{
> + writel(val, base + offset);
> + pr_info("%s 0x%x to offset 0x%lx\n", __func__, val, offset);
> +}
> +#else
> +#define alt_qspi_readl(base, offset) readl(base+offset)
> +#define alt_qspi_writel(val, base, offset) writel(val, base + offset)

This use of macros is wrong, but it'll be dropped anyway ...

> +#endif
> +
> +static void altera_quadspi_chip_select(struct altera_quadspi *q, u32 bank)
> +{
> + u32 val = 0;
> +
> + switch (bank) {
> + case 0:
> + val = QUADSPI_CHIP_SELECT_0;
> + break;
> + case 1:
> + val = QUADSPI_CHIP_SELECT_1;
> + break;
> + case 2:
> + val = QUADSPI_CHIP_SELECT_2;
> + break;
> + default:
> + dev_err(q->dev, "invalid bank\n");
> + return;
> + }

So this is basically
switch ...
case 0:
return BIT(0);
case 1:
return BIT(1);
...

This can be simplified, right ? :)

> + alt_qspi_writel(val, q->csr_base, QUADSPI_CHIP_SELECT_REG);
> +}
> +
> +static int altera_quadspi_write_reg(struct spi_nor *nor, u8 opcode, u8 *val,
> + int len)
> +{
> + struct altera_quadspi_flash *flash = nor->priv;
> + struct altera_quadspi *q = flash->q;
> +
> + altera_quadspi_chip_select(q, flash->bank);

Look at the mutex usage in cadence qspi driver ; if you have multiple
flashes and you access both at the same time, you'll run into a nasty
race if you don't have that locking in place. UBI on both can trigger
that. Look for "bus_mutex" in that driver.

> + switch (opcode) {
> + case SPINOR_OP_WREN:
> + dev_dbg(q->dev, "%s enabling write\n", __func__);
> + alt_qspi_writel(QUADSPI_MEM_OP_SECTOR_WRITE_ENABLE_CMD,
> + q->csr_base, QUADSPI_MEM_OP_REG);
> + break;
> +
> + case SPINOR_OP_CHIP_ERASE:
> + alt_qspi_writel(QUADSPI_MEM_OP_BULK_ERASE_CMD,
> + q->csr_base, QUADSPI_MEM_OP_REG);
> + break;
> +
> + default:
> + dev_dbg(q->dev, "%s UNHANDLED write_reg 0x%x\n",
> + __func__, opcode);
> +
> + }
> +
> + return 0;
> +}
> +
> +static int altera_quadspi_read_reg(struct spi_nor *nor, u8 opcode, u8 *val,
> + int len)
> +{
> + struct altera_quadspi_flash *flash = nor->priv;
> + struct altera_quadspi *q = flash->q;
> + u32 data = 0;
> +
> + memset(val, 0, len);
> +
> + altera_quadspi_chip_select(q, flash->bank);
> +
> + switch (opcode) {
> + case SPINOR_OP_RDSR:
> + data = alt_qspi_readl(q->csr_base, QUADSPI_SR_REG);
> + dev_dbg(q->dev, "%s RDSR 0x%x\n", __func__, data);
> + *val = (u8)data & QUADSPI_SR_MASK;
> + break;
> + case SPINOR_OP_RDID:
> + if (q->opcode_id == EPCS_OPCODE_ID)
> + data = alt_qspi_readl(q->csr_base, QUADSPI_SID_REG);
> + else
> + data = alt_qspi_readl(q->csr_base, QUADSPI_RDID_REG);
> +
> + *((u32 *)val) = data;

What are these awful casts ?

> + break;
> + case SPINOR_OP_RDFSR:
> + data = alt_qspi_readl(q->csr_base, QUADSPI_FLAG_STATUS_REG);
> + dev_dbg(q->dev, "%s RDFSR 0x%x\n", __func__, data);
> + *val = (u8)(data & 0xff);
> + break;
> + default:
> + dev_dbg(q->dev, "%s UNHANDLED read_reg 0x%x\n",
> + __func__, opcode);
> + *val = 0;
> + break;
> + }
> + return 0;
> +}
> +
> +static int altera_quadspi_write_erase_check(struct spi_nor *nor,
> + bool write_erase)
> +{
> + struct altera_quadspi_flash *flash = nor->priv;
> + struct altera_quadspi *q = flash->q;
> + u32 val;
> + u32 mask;
> +
> + if (write_erase)
> + mask = QUADSPI_ISR_ILLEGAL_WRITE_MASK;
> + else
> + mask = QUADSPI_ISR_ILLEGAL_ERASE_MASK;
> +
> + val = alt_qspi_readl(q->csr_base, QUADSPI_ISR_REG);
> +
> + if (val & mask) {
> + dev_err(nor->dev,
> + "write/erase failed, sector might be protected\n");
> + alt_qspi_writel(0, q->csr_base, QUADSPI_FLAG_STATUS_REG);
> +
> + return -EIO;
> + }
> +
> + return 0;
> +}
> +
> +static int altera_quadspi_addr_to_sector(struct mtd_info *mtd, uint64_t offset)
> +{
> + if (mtd->erasesize_shift)
> + return offset >> mtd->erasesize_shift;
> + do_div(offset, mtd->erasesize);
> + return offset;
> +}
> +
> +static int altera_quadspi_erase(struct spi_nor *nor, loff_t offset)
> +{
> + struct altera_quadspi_flash *flash = nor->priv;
> + struct altera_quadspi *q = flash->q;
> + struct mtd_info *mtd = &nor->mtd;
> + u32 val;
> + int sector_value;
> +
> + altera_quadspi_chip_select(q, flash->bank);
> +
> + sector_value = altera_quadspi_addr_to_sector(mtd, offset);
> +
> + dev_dbg(q->dev, "%s sector %d\n", __func__, sector_value);
> +
> + if (sector_value < 0)
> + return -EINVAL;
> +
> + val = (sector_value << 8) & QUADSPI_MEM_OP_SECTOR_VALUE_MASK;
> +
> + val |= QUADSPI_MEM_OP_SECTOR_ERASE_CMD;
> +
> + alt_qspi_writel(val, q->csr_base, QUADSPI_MEM_OP_REG);
> +
> + dev_dbg(q->dev, "%s SR=0x%x FSR=0x%x\n", __func__,
> + alt_qspi_readl(q->csr_base, QUADSPI_SR_REG),
> + alt_qspi_readl(q->csr_base, QUADSPI_FLAG_STATUS_REG));
> +
> + return altera_quadspi_write_erase_check(nor, ERASE_CHECK);
> +}
> +
> +#define WINDOW_ALIGN 4
> +#define WINDOW_MASK (WINDOW_ALIGN - 1)

What are these undocumented macros in the middle of the code ?

> +static ssize_t altera_quadspi_windowed_read(struct altera_quadspi *q,
> + loff_t from,
> + size_t len, u_char *buf)
> +{
> + size_t bytes_left = len;
> + size_t bytes_to_read, i;
> + loff_t next_window_off;
> + u64 start_window;
> + u32 window;
> + u32 *dst;
> +
> + if ((from & WINDOW_MASK) || (len & WINDOW_MASK) ||
> + !IS_ALIGNED((unsigned long)buf, WINDOW_ALIGN)) {
> + dev_err(q->dev, "%s only 32 bit aligned accesses allowed\n",
> + __func__);
> + return 0;
> + }
> +
> + start_window = from;
> + do_div(start_window, q->window_size);
> + window = (u32)(start_window & 0xffffffff);
> +
> + next_window_off = (window + 1) * q->window_size;
> +
> + while (bytes_left > 0) {
> +
> + writel(window, q->window_base + QUADSPI_WIN_SEL_REG);
> +
> + bytes_to_read = min((size_t)bytes_left,
> + (size_t)(next_window_off - from));
> +
> + dev_dbg(q->dev,
> + "window%u fr0x%llx next0x%llx left%zu num0x%zx\n",
> + window, from, next_window_off, bytes_left,
> + bytes_to_read);
> +
> + dst = (u32 *)buf;
> + for (i = 0; i < bytes_to_read; i += 4, dst++)
> + *dst = readl(q->data_base +
> + (from & (q->window_size - 1)) + i);

ioread32_rep and co. ? Again, look at the CQSPI driver.

> + bytes_left -= bytes_to_read;
> + buf += bytes_to_read;
> + from += bytes_to_read;
> + window++;
> + next_window_off += q->window_size;
> + }
> +
> + return len;
> +}
> +static ssize_t altera_quadspi_windowed_write(struct altera_quadspi *q,
> + loff_t to, size_t len,
> + const u_char *buf)
> +{
> + size_t bytes_left = len;
> + u32 window_mask = q->window_size - 1;
> + u32 read_back;
> + size_t bytes_to_write, i;
> + loff_t next_window_off;
> + u64 start_window;
> + u32 window;
> + const u32 *src;
> + u32 words_can_write;
> +
> + if ((to & WINDOW_MASK) || (len & WINDOW_MASK) ||
> + !IS_ALIGNED((unsigned long)buf, WINDOW_ALIGN)) {
> + dev_err(q->dev, "%s only 32 bit aligned accesses allowed\n",
> + __func__);
> + return 0;
> + }
> +
> + start_window = to;
> + do_div(start_window, q->window_size);
> + window = (u32)(start_window & 0xffffffff);
> +
> + next_window_off = (window + 1) * q->window_size;
> +
> + while (bytes_left > 0) {
> +
> + writel(window, q->window_base + QUADSPI_WIN_SEL_REG);
> +
> + bytes_to_write = min((size_t)bytes_left,
> + (size_t)(next_window_off - to));
> +
> + dev_dbg(q->dev,
> + "window%u to0x%llx next0x%llx left%zu num0x%zx\n",
> + window, to, next_window_off, bytes_left,
> + bytes_to_write);

DTTO , either memcpy_toio or iowrite32_rep

> + src = (u32 *)buf;
> + for (i = 0; i < bytes_to_write;) {
> + words_can_write =
> + readl(q->window_base + QUADSPI_WIN_OCC_REG) >>
> + QUADSPI_WIN_OCC_SFT;
> + dev_dbg(q->dev, "can write 0x%x\n", words_can_write);
> +
> + for (; words_can_write > 0; words_can_write--) {
> + writel(*src,
> + q->data_base +
> + (to & window_mask) + i);
> + read_back = readl(q->data_base +
> + (to & window_mask) + i);
> + if (*src != read_back) {
> + dev_err(q->dev, "%s 0x%x != 0x%x\n",
> + __func__, *src, read_back);
> + return (len - bytes_left);
> + }
> + i += 4;
> + src++;
> + }
> + }
> +
> + bytes_left -= bytes_to_write;
> + buf += bytes_to_write;
> + to += bytes_to_write;
> + window++;
> + next_window_off += q->window_size;
> + }
> +
> + return len;
> +}
> +
> +static ssize_t altera_quadspi_read(struct spi_nor *nor, loff_t from, size_t len,
> + u_char *buf)
> +{
> + struct altera_quadspi_flash *flash = nor->priv;
> + struct altera_quadspi *q = flash->q;
> + size_t i;
> +
> + altera_quadspi_chip_select(q, flash->bank);
> +
> + if (q->window_size)
> + altera_quadspi_windowed_read(q, from, len, buf);
> + else
> + memcpy_fromio(buf, q->data_base + from, len);
> +
> + if (q->flags & ALTERA_QUADSPI_FL_BITREV_READ) {
> + for (i = 0; i < len; i++, buf++)
> + *buf = bitrev8(*buf);
> + }
> +
> + return len;
> +}
> +
> +static ssize_t altera_quadspi_write(struct spi_nor *nor, loff_t to,
> + size_t len, const u_char *buf)
> +{
> + struct altera_quadspi_flash *flash = nor->priv;
> + struct altera_quadspi *q = flash->q;
> + u_char *bitrev_buf = NULL;
> + const u_char *src;
> + u_char *dst;
> + size_t i;
> + int ret = 0;
> +
> + altera_quadspi_chip_select(q, flash->bank);
> +
> + if (q->flags & ALTERA_QUADSPI_FL_BITREV_WRITE) {
> + bitrev_buf = devm_kzalloc(q->dev, len, GFP_KERNEL);
> + if (!bitrev_buf)
> + return 0;
> +
> + src = buf;
> + dst = bitrev_buf;
> + for (i = 0; i < len; i++, src++, dst++)
> + *dst = bitrev8(*src);
> +
> + buf = bitrev_buf;
> + }
> +
> + if (q->window_size)
> + altera_quadspi_windowed_write(q, to, len, buf);
> + else
> + memcpy_toio(q->data_base + to, buf, len);
> +
> +
> + if (bitrev_buf)
> + devm_kfree(q->dev, bitrev_buf);
> +
> + ret = altera_quadspi_write_erase_check(nor, WRITE_CHECK);
> +
> + return len;
> +
> +}
> +
> +static int altera_quadspi_lock(struct spi_nor *nor, loff_t ofs, uint64_t len)
> +{
> + struct altera_quadspi_flash *flash = nor->priv;
> + struct altera_quadspi *q = flash->q;
> + struct mtd_info *mtd = &nor->mtd;
> + uint32_t offset = ofs;
> + u32 sector_start, sector_end;
> + uint64_t num_sectors;
> + u32 mem_op;
> + u32 sr_bp;
> + u32 sr_tb;
> +
> + altera_quadspi_chip_select(q, flash->bank);
> +
> + sector_start = offset;
> + sector_end = altera_quadspi_addr_to_sector(mtd, offset + len);
> + num_sectors = mtd->size;
> + do_div(num_sectors, mtd->erasesize);
> +
> + dev_dbg(nor->dev, "%s: sector start is %u,sector end is %u\n",
> + __func__, sector_start, sector_end);
> +
> + if (sector_start >= num_sectors / 2) {
> + sr_bp = fls(num_sectors - 1 - sector_start) + 1;
> + sr_tb = 0;
> + } else if ((sector_end < num_sectors / 2) &&
> + (q->opcode_id != EPCS_OPCODE_ID)) {
> + sr_bp = fls(sector_end) + 1;
> + sr_tb = 1;
> + } else {
> + sr_bp = 16;
> + sr_tb = 0;
> + }
> +
> + mem_op = (sr_tb << 12) | (sr_bp << 8);
> + mem_op &= QUADSPI_MEM_OP_SECTOR_PROTECT_VALUE_MASK;
> + mem_op |= QUADSPI_MEM_OP_SECTOR_PROTECT_CMD;
> +
> + alt_qspi_writel(mem_op, q->csr_base, QUADSPI_MEM_OP_REG);
> +
> + return 0;
> +}
> +
> +static int altera_quadspi_unlock(struct spi_nor *nor, loff_t ofs, uint64_t len)
> +{
> + struct altera_quadspi_flash *flash = nor->priv;
> + struct altera_quadspi *q = flash->q;
> + u32 mem_op;
> +
> + dev_dbg(nor->dev, "Unlock all protected area\n");
> +
> + altera_quadspi_chip_select(q, flash->bank);
> +
> + mem_op = QUADSPI_MEM_OP_SECTOR_PROTECT_CMD;
> + alt_qspi_writel(mem_op, q->csr_base, QUADSPI_MEM_OP_REG);
> +
> + return 0;
> +}
> +
> +static int altera_quadspi_setup_banks(struct device *dev,
> + u32 bank, struct device_node *np)
> +{
> + struct altera_quadspi *q = dev_get_drvdata(dev);
> + struct altera_quadspi_flash *flash;
> + struct spi_nor *nor;
> + int ret = 0;
> + char modalias[40] = {0};
> + struct spi_nor_hwcaps hwcaps = {
> + .mask = SNOR_HWCAPS_READ |
> + SNOR_HWCAPS_READ_FAST |
> + SNOR_HWCAPS_READ_1_1_2 |
> + SNOR_HWCAPS_READ_1_1_4 |
> + SNOR_HWCAPS_PP,
> + };
> +
> + if (bank > q->num_flashes - 1)
> + return -EINVAL;
> +
> + altera_quadspi_chip_select(q, bank);
> +
> + flash = devm_kzalloc(q->dev, sizeof(*flash), GFP_KERNEL);
> + if (!flash)
> + return -ENOMEM;
> +
> + q->flash[bank] = flash;
> + nor = &flash->nor;
> + nor->dev = dev;
> + nor->priv = flash;
> + nor->mtd.priv = nor;
> + flash->q = q;
> + flash->bank = bank;
> + spi_nor_set_flash_node(nor, np);
> +
> + /* spi nor framework*/
> + nor->read_reg = altera_quadspi_read_reg;
> + nor->write_reg = altera_quadspi_write_reg;
> + nor->read = altera_quadspi_read;
> + nor->write = altera_quadspi_write;
> + nor->erase = altera_quadspi_erase;
> + nor->flash_lock = altera_quadspi_lock;
> + nor->flash_unlock = altera_quadspi_unlock;
> +
> + /* scanning flash and checking dev id */
> +#ifdef CONFIG_OF
> + if (np && (of_modalias_node(np, modalias, sizeof(modalias)) < 0))
> + return -EINVAL;
> +#endif
> +
> + ret = spi_nor_scan(nor, modalias, &hwcaps);
> + if (ret) {
> + dev_err(nor->dev, "flash not found\n");
> + return ret;
> + }
> +
> + ret = mtd_device_register(&nor->mtd, NULL, 0);
> +
> + altera_quadspi_unlock(nor, 0, 0);
> +
> + return ret;
> +}
> +
> +int altera_quadspi_create(struct device *dev, void __iomem *csr_base,
> + void __iomem *data_base, void __iomem *window_base,
> + size_t window_size, u32 flags)
> +{
> + struct altera_quadspi *q;
> +
> + q = devm_kzalloc(dev, sizeof(*q), GFP_KERNEL);
> + if (!q)
> + return -ENOMEM;
> +
> + q->dev = dev;
> + q->csr_base = csr_base;
> + q->data_base = data_base;
> + q->window_base = window_base;
> + q->window_size = window_size;
> +
> + q->flags = flags;
> +
> + dev_set_drvdata(dev, q);
> +
> + dev_dbg(dev, "%s SR=0x%x FSR=0x%x\n", __func__,
> + alt_qspi_readl(q->csr_base, QUADSPI_SR_REG),
> + alt_qspi_readl(q->csr_base, QUADSPI_FLAG_STATUS_REG));
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(altera_quadspi_create);
> +
> +int altera_qspi_add_bank(struct device *dev,
> + u32 bank, struct device_node *np)
> +{
> + struct altera_quadspi *q = dev_get_drvdata(dev);
> +
> + if (q->num_flashes >= ALTERA_QUADSPI_MAX_NUM_FLASH_CHIP)
> + return -ENOMEM;
> +
> + q->num_flashes++;
> +
> + return altera_quadspi_setup_banks(dev, bank, np);
> +}
> +EXPORT_SYMBOL_GPL(altera_qspi_add_bank);
> +
> +int altera_quadspi_remove_banks(struct device *dev)
> +{
> + struct altera_quadspi *q = dev_get_drvdata(dev);
> + struct altera_quadspi_flash *flash;
> + int i;
> + int ret = 0;
> +
> + /* clean up for all nor flash */
> + for (i = 0; i < q->num_flashes; i++) {
> + flash = q->flash[i];
> + if (!flash)
> + continue;
> +
> + /* clean up mtd stuff */
> + ret = mtd_device_unregister(&flash->nor.mtd);
> + if (ret) {
> + dev_err(dev, "error removing mtd\n");
> + return ret;
> + }
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(altera_quadspi_remove_banks);
> +
> +MODULE_AUTHOR("Viet Nga Dao <vndao@xxxxxxxxxx>");
> +MODULE_AUTHOR("Yong Sern Lau <lau.yong.sern@xxxxxxxxx>");
> +MODULE_AUTHOR("Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("Altera QuadSPI Version 2 Driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/include/linux/mtd/altera-quadspi.h b/include/linux/mtd/altera-quadspi.h
> new file mode 100644
> index 0000000..58f31ee
> --- /dev/null
> +++ b/include/linux/mtd/altera-quadspi.h
> @@ -0,0 +1,28 @@
> +/*
> + *
> + * Copyright 2017 Intel Corporation, Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + */
> +#ifndef __ALTERA_QUADSPI_H
> +#define __ALTERA_QUADSPI_H
> +
> +#include <linux/device.h>
> +
> +#define ALTERA_QUADSPI_FL_BITREV_READ BIT(0)
> +#define ALTERA_QUADSPI_FL_BITREV_WRITE BIT(1)
> +
> +#define ALTERA_QUADSPI_MAX_NUM_FLASH_CHIP 3
> +
> +int altera_quadspi_create(struct device *dev, void __iomem *csr_base,
> + void __iomem *data_base, void __iomem *window_reg,
> + size_t window_size, u32 flags);
> +
> +int altera_qspi_add_bank(struct device *dev,
> + u32 bank, struct device_node *np);
> +
> +int altera_quadspi_remove_banks(struct device *dev);

Why is this header needed at all ?

> +#endif
>


--
Best regards,
Marek Vasut