[PATCH v3 2/2] mtd: spi-nor: add driver for STM32 quad spi flash controller
Cyrille Pitchen
cyrille.pitchen at wedev4u.fr
Wed Apr 12 13:28:40 PDT 2017
Hi Ludovic,
Globally I will say this is pretty good and, IMHO, almost ready to be
merged into the github/spi-nor tree.
I have few comments, all but one are mainly recommendations hence not
blocking on my side. However one should be fixed. Even if not critical
and very unlikely to happen, I think it is more a potential bug than a
simple cosmetic issue.
So if you have time to prepare a new series, I will try if possible to
add your patch into the PR, which should be sent ideally before the end
of the week. I can't give you any guarantee since the timing is really
short now. Besides Marek still needs to add his Acked-by / Reviewed-by
once satisfied, otherwise your patch will have to wait for the next release.
If something I say is wrong or if you disagree with me, do not hesitate:
we can discuss and I can change my mind.
So my comments to follow:
Le 12/04/2017 à 19:06, Ludovic Barre a écrit :
> From: Ludovic Barre <ludovic.barre at st.com>
>
> The quadspi is a specialized communication interface targeting single,
> dual or quad SPI Flash memories.
>
> It can operate in any of the following modes:
> -indirect mode: all the operations are performed using the quadspi
> registers
> -read memory-mapped mode: the external Flash memory is mapped to the
> microcontroller address space and is seen by the system as if it was
> an internal memory
>
> Signed-off-by: Ludovic Barre <ludovic.barre at st.com>
> ---
> drivers/mtd/spi-nor/Kconfig | 7 +
> drivers/mtd/spi-nor/Makefile | 1 +
> drivers/mtd/spi-nor/stm32-quadspi.c | 693 ++++++++++++++++++++++++++++++++++++
> 3 files changed, 701 insertions(+)
> create mode 100644 drivers/mtd/spi-nor/stm32-quadspi.c
>
> diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig
> index 7252087..bfdfb1e 100644
> --- a/drivers/mtd/spi-nor/Kconfig
> +++ b/drivers/mtd/spi-nor/Kconfig
> @@ -106,4 +106,11 @@ config SPI_INTEL_SPI_PLATFORM
> To compile this driver as a module, choose M here: the module
> will be called intel-spi-platform.
>
> +config SPI_STM32_QUADSPI
> + tristate "STM32 Quad SPI controller"
> + depends on ARCH_STM32
> + help
> + This enables support for the STM32 Quad SPI controller.
> + We only connect the NOR to this controller.
> +
> endif # MTD_SPI_NOR
> diff --git a/drivers/mtd/spi-nor/Makefile b/drivers/mtd/spi-nor/Makefile
> index 72238a7..285aab8 100644
> --- a/drivers/mtd/spi-nor/Makefile
> +++ b/drivers/mtd/spi-nor/Makefile
> @@ -8,3 +8,4 @@ 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
> diff --git a/drivers/mtd/spi-nor/stm32-quadspi.c b/drivers/mtd/spi-nor/stm32-quadspi.c
> new file mode 100644
> index 0000000..9e90dee
> --- /dev/null
> +++ b/drivers/mtd/spi-nor/stm32-quadspi.c
> @@ -0,0 +1,693 @@
> +/*
> + * stm32_quadspi.c
> + *
> + * Copyright (C) 2017, Ludovic Barre
> + *
> + * License terms: GNU General Public License (GPL), version 2
> + */
> +#include <linux/clk.h>
> +#include <linux/errno.h>
> +#include <linux/io.h>
> +#include <linux/iopoll.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/mtd/mtd.h>
> +#include <linux/mtd/partitions.h>
> +#include <linux/mtd/spi-nor.h>
> +#include <linux/mutex.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/reset.h>
> +
> +#define QUADSPI_CR 0x00
> +#define CR_EN BIT(0)
> +#define CR_ABORT BIT(1)
> +#define CR_DMAEN BIT(2)
> +#define CR_TCEN BIT(3)
> +#define CR_SSHIFT BIT(4)
> +#define CR_DFM BIT(6)
> +#define CR_FSEL BIT(7)
> +#define CR_FTHRES_SHIFT 8
> +#define CR_FTHRES_MASK GENMASK(12, 8)
> +#define CR_FTHRES(n) (((n) << CR_FTHRES_SHIFT) & CR_FTHRES_MASK)
> +#define CR_TEIE BIT(16)
> +#define CR_TCIE BIT(17)
> +#define CR_FTIE BIT(18)
> +#define CR_SMIE BIT(19)
> +#define CR_TOIE BIT(20)
> +#define CR_PRESC_SHIFT 24
> +#define CR_PRESC_MASK GENMASK(31, 24)
> +#define CR_PRESC(n) (((n) << CR_PRESC_SHIFT) & CR_PRESC_MASK)
> +
> +#define QUADSPI_DCR 0x04
> +#define DCR_CSHT_SHIFT 8
> +#define DCR_CSHT_MASK GENMASK(10, 8)
> +#define DCR_CSHT(n) (((n) << DCR_CSHT_SHIFT) & DCR_CSHT_MASK)
> +#define DCR_FSIZE_SHIFT 16
> +#define DCR_FSIZE_MASK GENMASK(20, 16)
> +#define DCR_FSIZE(n) (((n) << DCR_FSIZE_SHIFT) & DCR_FSIZE_MASK)
> +
> +#define QUADSPI_SR 0x08
> +#define SR_TEF BIT(0)
> +#define SR_TCF BIT(1)
> +#define SR_FTF BIT(2)
> +#define SR_SMF BIT(3)
> +#define SR_TOF BIT(4)
> +#define SR_BUSY BIT(5)
> +#define SR_FLEVEL_SHIFT 8
> +#define SR_FLEVEL_MASK GENMASK(13, 8)
> +
> +#define QUADSPI_FCR 0x0c
> +#define FCR_CTCF BIT(1)
> +
> +#define QUADSPI_DLR 0x10
> +
> +#define QUADSPI_CCR 0x14
> +#define CCR_INST_SHIFT 0
> +#define CCR_INST_MASK GENMASK(7, 0)
> +#define CCR_INST(n) (((n) << CCR_INST_SHIFT) & CCR_INST_MASK)
> +#define CCR_IMODE_NONE (0 << 8)
> +#define CCR_IMODE_1 (1 << 8)
> +#define CCR_IMODE_2 (2 << 8)
> +#define CCR_IMODE_4 (3 << 8)
> +#define CCR_ADMODE_NONE (0 << 10)
> +#define CCR_ADMODE_1 (1 << 10)
> +#define CCR_ADMODE_2 (2 << 10)
> +#define CCR_ADMODE_4 (3 << 10)
For bitfields, it would have been better to use (1u << 8) that is
unsigned int instead of signed int. It might avoid some warnings or even
bugs depending on how you use those macros, especially if you were using
BIT(31). The GENMASK() macro generates an unsigned int on its side.
However, I guess you have tested your driver so if you have noticed any
issue, I will say this is not blocking for me :)
You don't use BIT(31) and I don't see any use of the >> operator so I
think it should be safe. My comment is just a recommendation for the
next time!
To be fair, you can point out the atmel_qspi.c driver and I did the same
mistake but like you, I didn't use the >> operator with the bitmask I
have defined :p
> +#define CCR_ADSIZE_SHIFT 12
> +#define CCR_ADSIZE_MASK GENMASK(13, 12)
> +#define CCR_ADSIZE(n) (((n) << CCR_ADSIZE_SHIFT) & CCR_ADSIZE_MASK)
> +#define CCR_ABMODE_NONE (0 << 14)
> +#define CCR_ABMODE_1 (1 << 14)
> +#define CCR_ABMODE_2 (2 << 14)
> +#define CCR_ABMODE_4 (3 << 14)
> +#define CCR_ABSIZE_8 (0 << 16)
> +#define CCR_ABSIZE_16 (1 << 16)
> +#define CCR_ABSIZE_24 (2 << 16)
> +#define CCR_ABSIZE_32 (3 << 16)
> +#define CCR_DCYC_SHIFT 18
> +#define CCR_DCYC_MASK GENMASK(22, 18)
> +#define CCR_DCYC(n) (((n) << CCR_DCYC_SHIFT) & CCR_DCYC_MASK)
> +#define CCR_DMODE_NONE (0 << 24)
> +#define CCR_DMODE_1 (1 << 24)
> +#define CCR_DMODE_2 (2 << 24)
> +#define CCR_DMODE_4 (3 << 24)
> +#define CCR_FMODE_INDW (0 << 26)
> +#define CCR_FMODE_INDR (1 << 26)
> +#define CCR_FMODE_APM (2 << 26)
> +#define CCR_FMODE_MM (3 << 26)
> +
> +#define QUADSPI_AR 0x18
> +#define QUADSPI_ABR 0x1c
> +#define QUADSPI_DR 0x20
> +#define QUADSPI_PSMKR 0x24
> +#define QUADSPI_PSMAR 0x28
> +#define QUADSPI_PIR 0x2c
> +#define QUADSPI_LPTR 0x30
> +#define LPTR_DFT_TIMEOUT 0x10
> +
> +#define FSIZE_VAL(size) (__fls(size) - 1)
> +
> +#define STM32_MAX_MMAP_SZ SZ_256M
> +#define STM32_MAX_NORCHIP 2
> +
> +#define STM32_QSPI_FIFO_TIMEOUT_US 30000
> +#define STM32_QSPI_BUSY_TIMEOUT_US 100000
> +
> +struct stm32_qspi_flash {
> + struct spi_nor nor;
> + u32 cs;
> + u32 fsize;
> + u32 presc;
> + u32 read_mode;
> + struct stm32_qspi *qspi;
> +};
> +
> +struct stm32_qspi {
> + struct device *dev;
> + void __iomem *io_base;
> + void __iomem *mm_base;
> + resource_size_t mm_size;
> + u32 nor_num;
> + struct clk *clk;
> + u32 clk_rate;
> + struct stm32_qspi_flash flash[STM32_MAX_NORCHIP];
> + struct completion cmd_completion;
> +
> + /*
> + * to protect device configuration, could be different between
> + * 2 flash access (bk1, bk2)
> + */
> + struct mutex lock;
> +};
> +
> +struct stm32_qspi_cmd {
> + u8 addr_width;
> + u8 dummy;
> + bool tx_data;
> + u8 opcode;
> + u32 framemode;
> + u32 qspimode;
> + u32 addr;
> + size_t len;
> + void *buf;
> +};
> +
> +static int stm32_qspi_wait_cmd(struct stm32_qspi *qspi)
> +{
> + u32 cr;
> + int err = 0;
> +
> + if (readl_relaxed(qspi->io_base + QUADSPI_SR) & SR_TCF)
> + return 0;
> +
> + reinit_completion(&qspi->cmd_completion);
> + cr = readl_relaxed(qspi->io_base + QUADSPI_CR);
> + writel_relaxed(cr | CR_TCIE, qspi->io_base + QUADSPI_CR);
> +
> + if (!wait_for_completion_interruptible_timeout(&qspi->cmd_completion,
> + msecs_to_jiffies(1000)))
> + err = -ETIMEDOUT;
> +
> + writel_relaxed(cr, qspi->io_base + QUADSPI_CR);
> + return err;
> +}
> +
> +static int stm32_qspi_wait_nobusy(struct stm32_qspi *qspi)
> +{
> + u32 sr;
> +
> + return readl_relaxed_poll_timeout(qspi->io_base + QUADSPI_SR, sr,
> + !(sr & SR_BUSY), 10,
> + STM32_QSPI_BUSY_TIMEOUT_US);
> +}
> +
> +static void stm32_qspi_set_framemode(struct spi_nor *nor,
> + struct stm32_qspi_cmd *cmd, bool read)
> +{
> + u32 dmode = CCR_DMODE_1;
> +
> + cmd->framemode = CCR_IMODE_1;
> +
> + if (read) {
> + switch (nor->flash_read) {
> + case SPI_NOR_NORMAL:
> + case SPI_NOR_FAST:
> + dmode = CCR_DMODE_1;
> + break;
> + case SPI_NOR_DUAL:
> + dmode = CCR_DMODE_2;
> + break;
> + case SPI_NOR_QUAD:
> + dmode = CCR_DMODE_4;
> + break;
> + }
> + }
> +
> + cmd->framemode |= cmd->tx_data ? dmode : 0;
> + cmd->framemode |= cmd->addr_width ? CCR_ADMODE_1 : 0;
> +}
> +
> +static void stm32_qspi_read_fifo(u8 *val, void __iomem *addr)
> +{
> + *val = readb_relaxed(addr);
> +}
> +
> +static void stm32_qspi_write_fifo(u8 *val, void __iomem *addr)
> +{
> + writeb_relaxed(*val, addr);
> +}
> +
> +static int stm32_qspi_tx_poll(struct stm32_qspi *qspi,
> + const struct stm32_qspi_cmd *cmd)
> +{
> + void (*tx_fifo)(u8 *, void __iomem *);
> + u32 len = cmd->len, sr;
> + u8 *buf = cmd->buf;
> + int ret;
> +
> + if (cmd->qspimode == CCR_FMODE_INDW)
> + tx_fifo = stm32_qspi_write_fifo;
> + else
> + tx_fifo = stm32_qspi_read_fifo;
> +
> + while (len--) {
> + ret = readl_relaxed_poll_timeout(qspi->io_base + QUADSPI_SR,
> + sr, (sr & SR_FTF), 10,
> + STM32_QSPI_FIFO_TIMEOUT_US);
> + if (ret) {
> + dev_err(qspi->dev, "fifo timeout (stat:%#x)\n", sr);
> + break;
> + }
> + tx_fifo(buf++, qspi->io_base + QUADSPI_DR);
> + }
> +
> + return ret;
> +}
> +
> +static int stm32_qspi_tx_mm(struct stm32_qspi *qspi,
> + const struct stm32_qspi_cmd *cmd)
> +{
> + memcpy_fromio(cmd->buf, qspi->mm_base + cmd->addr, cmd->len);
> + return 0;
> +}
> +
> +static int stm32_qspi_tx(struct stm32_qspi *qspi,
> + const struct stm32_qspi_cmd *cmd)
> +{
> + if (!cmd->tx_data)
> + return 0;
> +
> + if (cmd->qspimode == CCR_FMODE_MM)
> + return stm32_qspi_tx_mm(qspi, cmd);
> +
> + return stm32_qspi_tx_poll(qspi, cmd);
> +}
> +
> +static int stm32_qspi_send(struct stm32_qspi_flash *flash,
> + const struct stm32_qspi_cmd *cmd)
> +{
> + struct stm32_qspi *qspi = flash->qspi;
> + u32 ccr, dcr, cr;
> + int err;
> +
> + err = stm32_qspi_wait_nobusy(qspi);
> + if (err)
> + goto abort;
> +
> + dcr = readl_relaxed(qspi->io_base + QUADSPI_DCR) & ~DCR_FSIZE_MASK;
> + dcr |= DCR_FSIZE(flash->fsize);
> + writel_relaxed(dcr, qspi->io_base + QUADSPI_DCR);
> +
> + cr = readl_relaxed(qspi->io_base + QUADSPI_CR);
> + cr &= ~CR_PRESC_MASK & ~CR_FSEL;
> + cr |= CR_PRESC(flash->presc);
> + cr |= flash->cs ? CR_FSEL : 0;
> + writel_relaxed(cr, qspi->io_base + QUADSPI_CR);
> +
> + if (cmd->tx_data)
> + writel_relaxed(cmd->len - 1, qspi->io_base + QUADSPI_DLR);
> +
> + ccr = cmd->framemode | cmd->qspimode;
> +
> + if (cmd->dummy)
> + ccr |= CCR_DCYC(cmd->dummy);
> +
> + if (cmd->addr_width)
> + ccr |= CCR_ADSIZE(cmd->addr_width - 1);
> +
> + ccr |= CCR_INST(cmd->opcode);
> + writel_relaxed(ccr, qspi->io_base + QUADSPI_CCR);
> +
> + if (cmd->addr_width && cmd->qspimode != CCR_FMODE_MM)
> + writel_relaxed(cmd->addr, qspi->io_base + QUADSPI_AR);
> +
> + err = stm32_qspi_tx(qspi, cmd);
> + if (err)
> + goto abort;
> +
> + if (cmd->qspimode != CCR_FMODE_MM) {
> + err = stm32_qspi_wait_cmd(qspi);
> + if (err)
> + goto abort;
> + writel_relaxed(FCR_CTCF, qspi->io_base + QUADSPI_FCR);
> + }
> +
> + return err;
> +
> +abort:
> + cr = readl_relaxed(qspi->io_base + QUADSPI_CR) | CR_ABORT;
> + writel_relaxed(cr, qspi->io_base + QUADSPI_CR);
> +
> + dev_err(qspi->dev, "%s abort err:%d\n", __func__, err);
> + return err;
> +}
> +
> +static int stm32_qspi_read_reg(struct spi_nor *nor,
> + u8 opcode, u8 *buf, int len)
> +{
> + struct stm32_qspi_flash *flash = nor->priv;
> + struct device *dev = flash->qspi->dev;
> + struct stm32_qspi_cmd cmd;
> +
> + dev_dbg(dev, "read_reg: cmd:%#.2x buf:%p len:%#x\n", opcode, buf, len);
> +
> + memset(&cmd, 0, sizeof(cmd));
> + cmd.opcode = opcode;
> + cmd.tx_data = true;
> + cmd.len = len;
> + cmd.buf = buf;
> + cmd.qspimode = CCR_FMODE_INDR;
> +
> + stm32_qspi_set_framemode(nor, &cmd, false);
> +
> + return stm32_qspi_send(flash, &cmd);
> +}
> +
> +static int stm32_qspi_write_reg(struct spi_nor *nor, u8 opcode,
> + u8 *buf, int len)
> +{
> + struct stm32_qspi_flash *flash = nor->priv;
> + struct device *dev = flash->qspi->dev;
> + struct stm32_qspi_cmd cmd;
> +
> + dev_dbg(dev, "write_reg: cmd:%#.2x buf:%p len:%#x\n", opcode, buf, len);
> +
> + memset(&cmd, 0, sizeof(cmd));
> + cmd.opcode = opcode;
> + cmd.tx_data = !!(buf && len > 0);
> + cmd.len = len;
> + cmd.buf = buf;
> + cmd.qspimode = CCR_FMODE_INDW;
> +
> + stm32_qspi_set_framemode(nor, &cmd, false);
> +
> + return stm32_qspi_send(flash, &cmd);
> +}
> +
> +static ssize_t stm32_qspi_read(struct spi_nor *nor, loff_t from, size_t len,
> + u_char *buf)
> +{
> + struct stm32_qspi_flash *flash = nor->priv;
> + struct stm32_qspi *qspi = flash->qspi;
> + struct stm32_qspi_cmd cmd;
> + int err;
> +
> + dev_dbg(qspi->dev, "read(%#.2x): buf:%p from:%#.8x len:%#x\n",
> + nor->read_opcode, buf, (u32)from, len);
> +
> + memset(&cmd, 0, sizeof(cmd));
> + cmd.opcode = nor->read_opcode;
> + cmd.addr_width = nor->addr_width;
> + cmd.addr = (u32)from;
> + cmd.tx_data = true;
> + cmd.dummy = nor->read_dummy;
> + cmd.len = len;
> + cmd.buf = buf;
> + cmd.qspimode = flash->read_mode;
> +
> + stm32_qspi_set_framemode(nor, &cmd, true);
> + err = stm32_qspi_send(flash, &cmd);
> +
> + return err ? err : len;
> +}
> +
> +static ssize_t stm32_qspi_write(struct spi_nor *nor, loff_t to, size_t len,
> + const u_char *buf)
> +{
> + struct stm32_qspi_flash *flash = nor->priv;
> + struct device *dev = flash->qspi->dev;
> + struct stm32_qspi_cmd cmd;
> + int err;
> +
> + dev_dbg(dev, "write(%#.2x): buf:%p to:%#.8x len:%#x\n",
> + nor->program_opcode, buf, (u32)to, len);
> +
> + memset(&cmd, 0, sizeof(cmd));
> + cmd.opcode = nor->program_opcode;
> + cmd.addr_width = nor->addr_width;
> + cmd.addr = (u32)to;
> + cmd.tx_data = true;
> + cmd.len = len;
> + cmd.buf = (void *)buf;
> + cmd.qspimode = CCR_FMODE_INDW;
> +
> + stm32_qspi_set_framemode(nor, &cmd, false);
> + err = stm32_qspi_send(flash, &cmd);
> +
> + return err ? err : len;
> +}
> +
> +static int stm32_qspi_erase(struct spi_nor *nor, loff_t offs)
> +{
> + struct stm32_qspi_flash *flash = nor->priv;
> + struct device *dev = flash->qspi->dev;
> + struct stm32_qspi_cmd cmd;
> +
> + dev_dbg(dev, "erase(%#.2x):offs:%#x\n", nor->erase_opcode, (u32)offs);
> +
> + memset(&cmd, 0, sizeof(cmd));
> + cmd.opcode = nor->erase_opcode;
> + cmd.addr_width = nor->addr_width;
> + cmd.addr = (u32)offs;
> + cmd.qspimode = CCR_FMODE_INDW;
> +
> + stm32_qspi_set_framemode(nor, &cmd, false);
> +
> + return stm32_qspi_send(flash, &cmd);
> +}
> +
> +static irqreturn_t stm32_qspi_irq(int irq, void *dev_id)
> +{
> + struct stm32_qspi *qspi = (struct stm32_qspi *)dev_id;
> + u32 cr, sr, fcr = 0;
> +
> + cr = readl_relaxed(qspi->io_base + QUADSPI_CR);
> + sr = readl_relaxed(qspi->io_base + QUADSPI_SR);
> +
> + if ((cr & CR_TCIE) && (sr & SR_TCF)) {
> + /* tx complete */
> + fcr |= FCR_CTCF;
> + complete(&qspi->cmd_completion);
> + } else {
> + dev_info_ratelimited(qspi->dev, "spurious interrupt\n");
> + }
> +
> + writel_relaxed(fcr, qspi->io_base + QUADSPI_FCR);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int stm32_qspi_prep(struct spi_nor *nor, enum spi_nor_ops ops)
> +{
> + struct stm32_qspi_flash *flash = nor->priv;
> + struct stm32_qspi *qspi = flash->qspi;
> +
> + mutex_lock(&qspi->lock);
> + return 0;
> +}
> +
> +static void stm32_qspi_unprep(struct spi_nor *nor, enum spi_nor_ops ops)
> +{
> + struct stm32_qspi_flash *flash = nor->priv;
> + struct stm32_qspi *qspi = flash->qspi;
> +
> + mutex_unlock(&qspi->lock);
> +}
> +
> +static int stm32_qspi_flash_setup(struct stm32_qspi *qspi,
> + struct device_node *np)
> +{
> + u32 width, flash_read, presc, cs_num, max_rate = 0;
> + struct stm32_qspi_flash *flash;
> + struct mtd_info *mtd;
> + int ret;
> +
> + of_property_read_u32(np, "reg", &cs_num);
> + if (cs_num >= STM32_MAX_NORCHIP)
> + return -EINVAL;
> +
> + of_property_read_u32(np, "spi-max-frequency", &max_rate);
> + if (!max_rate)
> + return -EINVAL;
> +
> + presc = DIV_ROUND_UP(qspi->clk_rate, max_rate) - 1;
> +
> + if (of_property_read_u32(np, "spi-rx-bus-width", &width))
> + width = 1;
> +
> + if (width == 4)
> + flash_read = SPI_NOR_QUAD;
> + else if (width == 2)
> + flash_read = SPI_NOR_DUAL;
> + else if (width == 1)
> + flash_read = SPI_NOR_NORMAL;
> + else
> + return -EINVAL;
> +
> + flash = &qspi->flash[cs_num];
> + flash->qspi = qspi;
> + flash->cs = cs_num;
> + flash->presc = presc;
> +
> + flash->nor.dev = qspi->dev;
> + spi_nor_set_flash_node(&flash->nor, np);
> + flash->nor.priv = flash;
> + mtd = &flash->nor.mtd;
> + mtd->priv = &flash->nor;
This line is not needed: spi_nor_scan() already initializes mtd->priv
with the nor pointer. Not blocking anyway.
> +
> + flash->nor.read = stm32_qspi_read;
> + flash->nor.write = stm32_qspi_write;
> + flash->nor.erase = stm32_qspi_erase;
> + flash->nor.read_reg = stm32_qspi_read_reg;
> + flash->nor.write_reg = stm32_qspi_write_reg;
> + flash->nor.prepare = stm32_qspi_prep;
> + flash->nor.unprepare = stm32_qspi_unprep;
A shared comment: your implementations of all those handlers seem good
to me. I didn't notice any particular mistake or issue :)
> +
> + writel_relaxed(LPTR_DFT_TIMEOUT, qspi->io_base + QUADSPI_LPTR);
> +
> + writel_relaxed(CR_PRESC(presc) | CR_FTHRES(3) | CR_TCEN | CR_SSHIFT
> + | CR_EN, qspi->io_base + QUADSPI_CR);
> +
> + /*
> + * in stm32 qspi controller, QUADSPI_DCR register has a fsize field
> + * which define the size of nor flash.
> + * if fsize is NULL, the controller can't sent spi-nor command.
> + * set a temporary value just to discover the nor flash with
> + * "spi_nor_scan". After, the right value (mtd->size) can be set.
> + */
> + flash->fsize = FSIZE_VAL(SZ_1K);
> +
> + ret = spi_nor_scan(&flash->nor, NULL, flash_read);
> + if (ret) {
> + dev_err(qspi->dev, "device scan failed\n");
At this point, (flash->qspi != NULL)
Hence in the control flow, once you have returned from
stm32_qspi__flash_setup() back into stm32_qspi_probe(), you handle the
reported error calling stm32_qspi_mtd_free().
This latest function test flash->qspi, which is not NULL, before calling
mtd_device_unregister(). However you did not register flash->nor.mtd at all.
Though not critical, can you fix this anyway, please?
I think, it's more a potential bug than a costmetic issue.
> + return ret;
> + }
> +
> + flash->fsize = FSIZE_VAL(mtd->size);
> +
> + flash->read_mode = CCR_FMODE_MM;
> + if (mtd->size > qspi->mm_size)
> + flash->read_mode = CCR_FMODE_INDR;
> +
> + writel_relaxed(DCR_CSHT(1), qspi->io_base + QUADSPI_DCR);
> +
> + ret = mtd_device_register(mtd, NULL, 0);
> + if (ret) {
> + dev_err(qspi->dev, "mtd device parse failed\n");
Almost the same mistake here: you shouldn't call mtd_device_unregister()
later from stm32_qspi_mtd_free() if mtd_devire_register() fails here.
> + return ret;
> + }
> +
> + dev_dbg(qspi->dev, "read mm:%s cs:%d bus:%d\n",
> + flash->read_mode == CCR_FMODE_MM ? "yes" : "no", cs_num, width);
> +
> + return 0;
> +}
> +
> +static void stm32_qspi_mtd_free(struct stm32_qspi *qspi)
> +{
> + int i;
> +
> + for (i = 0; i < STM32_MAX_NORCHIP; i++) {
> + if (qspi->flash[i].qspi)
> + mtd_device_unregister(&qspi->flash[i].nor.mtd);
> + }
IMHO, I guess braces {} in the for() loop are not needed here. So if
checkpatch doesn't complain it's ok for me, you can leave it as is if
you want. Otherwise, please fix!
> +}
> +
> +static int stm32_qspi_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct device_node *flash_np;
> + struct reset_control *rstc;
> + struct stm32_qspi *qspi;
> + struct resource *res;
> + int ret, irq;
> +
> + qspi = devm_kzalloc(dev, sizeof(*qspi), GFP_KERNEL);
> + if (!qspi)
> + return -ENOMEM;
> +
> + qspi->nor_num = of_get_child_count(dev->of_node);
> + if (!qspi->nor_num || qspi->nor_num > STM32_MAX_NORCHIP)
> + return -ENODEV;
> +
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi");
> + qspi->io_base = devm_ioremap_resource(dev, res);
> + if (IS_ERR(qspi->io_base))
> + return PTR_ERR(qspi->io_base);
> +
> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi_mm");
> + qspi->mm_base = devm_ioremap_resource(dev, res);
> + if (IS_ERR(qspi->mm_base))
> + return PTR_ERR(qspi->mm_base);
> +
> + qspi->mm_size = resource_size(res);
> +
> + irq = platform_get_irq(pdev, 0);
> + ret = devm_request_irq(dev, irq, stm32_qspi_irq, 0,
> + dev_name(dev), qspi);
> + if (ret) {
> + dev_err(dev, "failed to request irq\n");
> + return ret;
> + }
> +
> + init_completion(&qspi->cmd_completion);
> +
> + qspi->clk = devm_clk_get(dev, NULL);
> + if (IS_ERR(qspi->clk))
> + return PTR_ERR(qspi->clk);
> +
> + qspi->clk_rate = clk_get_rate(qspi->clk);
> + if (!qspi->clk_rate)
> + return -EINVAL;
> +
> + ret = clk_prepare_enable(qspi->clk);
> + if (ret) {
> + dev_err(dev, "can not enable the clock\n");
> + return ret;
> + }
> +
> + rstc = devm_reset_control_get(dev, NULL);
> + if (!IS_ERR(rstc)) {
> + reset_control_assert(rstc);
> + udelay(2);
> + reset_control_deassert(rstc);
> + }
> +
> + qspi->dev = dev;
> + platform_set_drvdata(pdev, qspi);
> + mutex_init(&qspi->lock);
> +
> + for_each_available_child_of_node(dev->of_node, flash_np) {
> + ret = stm32_qspi_flash_setup(qspi, flash_np);
> + if (ret) {
> + dev_err(dev, "unable to setup flash chip\n");
> + goto err_flash;
> + }
> + }
> +
> + return 0;
> +
> +err_flash:
> + mutex_destroy(&qspi->lock);
> + stm32_qspi_mtd_free(qspi);
> +
> + clk_disable_unprepare(qspi->clk);
> + return ret;
> +}
> +
> +static int stm32_qspi_remove(struct platform_device *pdev)
> +{
> + struct stm32_qspi *qspi = platform_get_drvdata(pdev);
> +
> + /* disable qspi */
> + writel_relaxed(0, qspi->io_base + QUADSPI_CR);
> +
> + stm32_qspi_mtd_free(qspi);
> + mutex_destroy(&qspi->lock);
> +
> + clk_disable_unprepare(qspi->clk);
> + return 0;
> +}
> +
> +static const struct of_device_id stm32_qspi_match[] = {
> + {.compatible = "st,stm32f469-qspi"},
> + {}
> +};
> +MODULE_DEVICE_TABLE(of, stm32_qspi_match);
> +
> +static struct platform_driver stm32_qspi_driver = {
> + .probe = stm32_qspi_probe,
> + .remove = stm32_qspi_remove,
> + .driver = {
> + .name = "stm32-quadspi",
> + .of_match_table = stm32_qspi_match,
> + },
> +};
> +module_platform_driver(stm32_qspi_driver);
> +
> +MODULE_ALIAS("platform:" DRIVER_NAME);
> +MODULE_AUTHOR("Ludovic Barre <ludovic.barre at st.com>");
> +MODULE_DESCRIPTION("STMicroelectronics STM32 quad spi driver");
> +MODULE_LICENSE("GPL v2");
>
Best regards,
Cyrille
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