[PATCH 2/2] mtd: spi-nor: add driver for STM32 quad spi flash controller
Marek Vasut
marek.vasut at gmail.com
Wed Mar 29 03:54:16 PDT 2017
On 03/27/2017 02:54 PM, Ludovic Barre wrote:
> 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>
Hi! I presume this is not compatible with the Cadence QSPI or any other
QSPI controller, huh ?
Mostly minor nits below ...
> ---
> drivers/mtd/spi-nor/Kconfig | 7 +
> drivers/mtd/spi-nor/Makefile | 1 +
> drivers/mtd/spi-nor/stm32-quadspi.c | 679 ++++++++++++++++++++++++++++++++++++
> 3 files changed, 687 insertions(+)
> create mode 100644 drivers/mtd/spi-nor/stm32-quadspi.c
[...]
> +struct stm32_qspi_cmd {
> + struct {
> + u32 addr_width:8;
> + u32 dummy:8;
> + u32 data:1;
> + } conf;
This could all be u8 ? Why this awful construct ?
> + 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;
Can readl_poll_timeout() or somesuch replace this function ?
> + 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, 100000);
> +}
> +
> +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->conf.data ? dmode : 0;
> + cmd->framemode |= cmd->conf.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, 30000);
Add macros for those ad-hoc timeouts.
> + 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_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->conf.data)
> + writel_relaxed(cmd->len - 1, qspi->io_base + QUADSPI_DLR);
> +
> + ccr = cmd->framemode | cmd->qspimode;
> +
> + if (cmd->conf.dummy)
> + ccr |= CCR_DCYC(cmd->conf.dummy);
> +
> + if (cmd->conf.addr_width)
> + ccr |= CCR_ADSIZE(cmd->conf.addr_width - 1);
> +
> + ccr |= CCR_INST(cmd->opcode);
> + writel_relaxed(ccr, qspi->io_base + QUADSPI_CCR);
> +
> + if (cmd->conf.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:
> + writel_relaxed(readl_relaxed(qspi->io_base + QUADSPI_CR)
> + | CR_ABORT, qspi->io_base + QUADSPI_CR);
Use a helper variable here too.
> + dev_err(qspi->dev, "%s abort err:%d\n", __func__, err);
> + return err;
> +}
[...]
> +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;
> +
> + 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;
> +
> + 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);
> +
> + /* a minimum fsize must be set to sent the command id */
> + flash->fsize = 25;
I don't understand why this is needed and the comment doesn't make
sense. Please fix.
> + ret = spi_nor_scan(&flash->nor, NULL, flash_read);
> + if (ret) {
> + dev_err(qspi->dev, "device scan failed\n");
> + return ret;
> + }
> +
> + flash->fsize = __fls(mtd->size) - 1;
> +
> + 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");
> + return ret;
> + }
> +
> + dev_dbg(qspi->dev, "read mm:%s cs:%d bus:%d\n",
> + qspi->read_mode == CCR_FMODE_MM ? "yes" : "no", cs_num, width);
> +
> + return 0;
> +}
[...]
--
Best regards,
Marek Vasut
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