[PATCH v1] driver: spi: add bcm iproc qspi support.

Jagan Teki jagan at amarulasolutions.com
Fri Oct 8 14:26:53 CEST 2021


On Wed, Aug 25, 2021 at 6:55 PM Bharat Kumar Reddy Gooty
<bharat.gooty at broadcom.com> wrote:
>
> From: Rayagonda Kokatanur <rayagonda.kokatanur at broadcom.com>
>
> IPROC qspi driver supports both BSPI and MSPI modes.
>
> Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur at broadcom.com>
> Signed-off-by: Bharat Gooty <bharat.gooty at broadcom.com>
> ---
>  drivers/spi/Kconfig      |   6 +
>  drivers/spi/Makefile     |   1 +
>  drivers/spi/iproc_qspi.c | 736 +++++++++++++++++++++++++++++++++++++++
>  drivers/spi/iproc_qspi.h |  18 +
>  4 files changed, 761 insertions(+)
>  create mode 100644 drivers/spi/iproc_qspi.c
>  create mode 100644 drivers/spi/iproc_qspi.h
>
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index e12699bec7..3253d6badf 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -178,6 +178,12 @@ config ICH_SPI
>           access the SPI NOR flash on platforms embedding this Intel
>           ICH IP core.
>
> +config IPROC_QSPI
> +       bool "QSPI driver for BCM iProc QSPI Controller"
> +       help
> +         This selects the BCM iProc QSPI controller.
> +         This driver support spi flash single, quad and memory reads.
> +
>  config KIRKWOOD_SPI
>         bool "Marvell Kirkwood SPI Driver"
>         help
> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
> index d2f24bccef..8697631870 100644
> --- a/drivers/spi/Makefile
> +++ b/drivers/spi/Makefile
> @@ -33,6 +33,7 @@ obj-$(CONFIG_FSL_DSPI) += fsl_dspi.o
>  obj-$(CONFIG_FSL_ESPI) += fsl_espi.o
>  obj-$(CONFIG_SYNQUACER_SPI) += spi-synquacer.o
>  obj-$(CONFIG_ICH_SPI) +=  ich.o
> +obj-$(CONFIG_IPROC_QSPI) += iproc_qspi.o
>  obj-$(CONFIG_KIRKWOOD_SPI) += kirkwood_spi.o
>  obj-$(CONFIG_MESON_SPIFC) += meson_spifc.o
>  obj-$(CONFIG_MPC8XX_SPI) += mpc8xx_spi.o
> diff --git a/drivers/spi/iproc_qspi.c b/drivers/spi/iproc_qspi.c
> new file mode 100644
> index 0000000000..89c6a56858
> --- /dev/null
> +++ b/drivers/spi/iproc_qspi.c
> @@ -0,0 +1,736 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright 2020-2021 Broadcom
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <errno.h>
> +#include <malloc.h>
> +#include <spi.h>
> +#include <asm/io.h>
> +#include <linux/err.h>
> +#include <linux/mtd/spi-nor.h>

Why spi-nor header in spi driver?

> +#include "iproc_qspi.h"
> +
> +/* 175MHz */
> +#define QSPI_AXI_CLK                           175000000
> +#define QSPI_DEF_SCK_FREQ                      50000000
> +#define QSPI_WAIT_TIMEOUT_MS                   200U
> +#define DWORD_ALIGNED(a)                       (!(((ulong)(a)) & 3))
> +
> +/* Chip attributes */
> +#define SPBR_MIN                               8U
> +#define SPBR_MAX                               255U
> +#define NUM_CDRAM                              16U
> +
> +#define CDRAM_PCS0                             2
> +#define CDRAM_CONT                             BIT(7)
> +#define CDRAM_BITS_EN                          BIT(6)
> +#define CDRAM_QUAD_MODE                                BIT(8)
> +#define CDRAM_RBIT_INPUT                       BIT(10)
> +#define MSPI_SPE                               BIT(6)
> +#define MSPI_CONT_AFTER_CMD                    BIT(7)
> +
> +/* Register fields */
> +#define MSPI_SPCR0_MSB_BITS_8                  0x00000020
> +#define BSPI_RAF_CONTROL_START_MASK            0x00000001
> +#define BSPI_RAF_STATUS_SESSION_BUSY_MASK      0x00000001
> +#define BSPI_RAF_STATUS_FIFO_EMPTY_MASK                0x00000002
> +#define BSPI_BITS_PER_PHASE_ADDR_MARK          0x00010000
> +#define BSPI_BITS_PER_CYCLE_DATA_SHIFT         0
> +#define BSPI_BITS_PER_CYCLE_ADDR_SHIFT         16
> +#define BSPI_STRAP_OVERRIDE_DATA_QUAD_SHIFT    3
> +#define BSPI_STRAP_OVERRIDE_DATA_DUAL_SHIFT    1
> +#define BSPI_STRAP_OVERRIDE_SHIFT              0
> +
> +/* MSPI registers */
> +#define MSPI_SPCR0_LSB_REG                     0x000
> +#define MSPI_SPCR0_MSB_REG                     0x004
> +#define MSPI_SPCR1_LSB_REG                     0x008
> +#define MSPI_SPCR1_MSB_REG                     0x00c
> +#define MSPI_NEWQP_REG                         0x010
> +#define MSPI_ENDQP_REG                         0x014
> +#define MSPI_SPCR2_REG                         0x018
> +#define MSPI_STATUS_REG                                0x020
> +#define MSPI_CPTQP_REG                         0x024
> +#define MSPI_TXRAM_REG                         0x040
> +#define MSPI_RXRAM_REG                         0x0c0
> +#define MSPI_CDRAM_REG                         0x140
> +#define MSPI_WRITE_LOCK_REG                    0x180
> +#define MSPI_DISABLE_FLUSH_GEN_REG             0x184
> +
> +/* BSPI registers */
> +#define BSPI_REVISION_ID_REG                   0x000
> +#define BSPI_SCRATCH_REG                       0x004
> +#define BSPI_MAST_N_BOOT_CTRL_REG              0x008
> +#define BSPI_BUSY_STATUS_REG                   0x00c
> +#define BSPI_INTR_STATUS_REG                   0x010
> +#define BSPI_B0_STATUS_REG                     0x014
> +#define BSPI_B0_CTRL_REG                       0x018
> +#define BSPI_B1_STATUS_REG                     0x01c
> +#define BSPI_B1_CTRL_REG                       0x020
> +#define BSPI_STRAP_OVERRIDE_CTRL_REG           0x024
> +#define BSPI_FLEX_MODE_ENABLE_REG              0x028
> +#define BSPI_BITS_PER_CYCLE_REG                        0x02C
> +#define BSPI_BITS_PER_PHASE_REG                        0x030
> +#define BSPI_CMD_AND_MODE_BYTE_REG             0x034
> +#define BSPI_FLASH_UPPER_ADDR_BYTE_REG         0x038
> +#define BSPI_XOR_VALUE_REG                     0x03C
> +#define BSPI_XOR_ENABLE_REG                    0x040
> +#define BSPI_PIO_MODE_ENABLE_REG               0x044
> +#define BSPI_PIO_IODIR_REG                     0x048
> +#define BSPI_PIO_DATA_REG                      0x04C
> +
> +/* RAF registers */
> +#define BSPI_RAF_START_ADDRESS_REG             0x00
> +#define BSPI_RAF_NUM_WORDS_REG                 0x04
> +#define BSPI_RAF_CTRL_REG                      0x08
> +#define BSPI_RAF_FULLNESS_REG                  0x0C
> +#define BSPI_RAF_WATERMARK_REG                 0x10
> +#define BSPI_RAF_STATUS_REG                    0x14
> +#define BSPI_RAF_READ_DATA_REG                 0x18
> +#define BSPI_RAF_WORD_CNT_REG                  0x1C
> +#define BSPI_RAF_CURR_ADDR_REG                 0x20
> +
> +#define XFER_DUAL                              BIT(30)
> +#define XFER_QUAD                              BIT(31)
> +
> +/* state */
> +enum bcm_qspi_state {
> +       QSPI_STATE_DISABLED,
> +       QSPI_STATE_MSPI,
> +       QSPI_STATE_BSPI
> +};
> +
> +/**
> + * struct bcmspi_priv - qspi private structure
> + *
> + * @max_hz: device transfer speed
> + * @spi_mode: spi mode (SPI_... flags)
> + * @frequency: spi max frequency
> + * @state: device state (MSPI/BSPI)
> + * @bspi_addr: bspi read address
> + * @mspi_16bit: mspi transfer mode
> + * @use_bspi: flag to indicate BSPI use for read operation
> + * @mspi: mspi registers block address
> + * @bspi: bspi registers block address
> + * @bspi_raf: bspi raf registers block address
> + */
> +struct bcmspi_priv {
> +       uint max_hz;
> +       uint spi_mode;
> +       s32 frequency;
> +       enum bcm_qspi_state state;
> +       u32 bspi_addr;
> +       int mspi_16bit;
> +       int mode_4byte;
> +       int use_bspi;
> +       void __iomem *mspi;
> +       void __iomem *bspi;
> +       void __iomem *bspi_raf;
> +};
> +
> +static void bspi_flush_prefetch_buffers(struct bcmspi_priv *priv)
> +{
> +       writel(0, priv->bspi + BSPI_B0_CTRL_REG);
> +       writel(0, priv->bspi + BSPI_B1_CTRL_REG);
> +       writel(1, priv->bspi + BSPI_B0_CTRL_REG);
> +       writel(1, priv->bspi + BSPI_B1_CTRL_REG);

Use BIT name instead of magic numbers?

> +}
> +
> +static int bcmspi_enable_bspi(struct bcmspi_priv *priv)
> +{
> +       if (priv->state == QSPI_STATE_BSPI)
> +               return 0;
> +
> +       /* Disable write lock */
> +       writel(0, priv->mspi + MSPI_WRITE_LOCK_REG);
> +       /* Flush prefetch buffers */
> +       bspi_flush_prefetch_buffers(priv);
> +       /* Switch to BSPI */
> +       writel(0, priv->bspi + BSPI_MAST_N_BOOT_CTRL_REG);
> +       /* Update state */
> +       priv->state = QSPI_STATE_BSPI;
> +
> +       return 0;
> +}
> +
> +static int bcmspi_disable_bspi(struct bcmspi_priv *priv)
> +{
> +       if (priv->state == QSPI_STATE_MSPI)
> +               return 0;
> +
> +       /* Switch to MSPI if not yet */
> +       if ((readl(priv->bspi + BSPI_MAST_N_BOOT_CTRL_REG) & 1) == 0) {
> +               ulong start = get_timer(0);
> +
> +               while (get_timer(start) <
> +                      QSPI_WAIT_TIMEOUT_MS * CONFIG_SYS_HZ / 1000) {
> +                       if ((readl(priv->bspi + BSPI_BUSY_STATUS_REG) & 1)
> +                           == 0) {
> +                               writel(1, priv->bspi +
> +                                      BSPI_MAST_N_BOOT_CTRL_REG);
> +                               udelay(1);
> +                               break;
> +                       }
> +                       udelay(1);
> +               }
> +               if ((readl(priv->bspi + BSPI_MAST_N_BOOT_CTRL_REG) & 1) != 1)
> +                       return -1;
> +       }
> +
> +       /* Update state */
> +       priv->state = QSPI_STATE_MSPI;

How can we find the state? can it be any reg bits?

> +
> +       return 0;
> +}
> +
> +static void bspi_set_4byte_mode(struct bcmspi_priv *priv, int enable)
> +{
> +       /* Disable flex mode first */
> +       writel(0, priv->bspi + BSPI_FLEX_MODE_ENABLE_REG);
> +
> +       if (enable) {
> +               /* Enable 32-bit address */
> +               setbits_le32(priv->bspi + BSPI_BITS_PER_PHASE_REG,
> +                            BSPI_BITS_PER_PHASE_ADDR_MARK);
> +               /* Enable flex mode to take effect */
> +               writel(1, priv->bspi + BSPI_FLEX_MODE_ENABLE_REG);
> +       } else {
> +               /* Disable 32-bit address */
> +               clrbits_le32(priv->bspi + BSPI_BITS_PER_PHASE_REG,
> +                            BSPI_BITS_PER_PHASE_ADDR_MARK);
> +               /* Clear upper address byte */
> +               writel(0, priv->bspi + BSPI_FLASH_UPPER_ADDR_BYTE_REG);
> +               /*
> +                * Flush prefetch buffers since 32MB window BSPI
> +                * could be used
> +                */
> +               bspi_flush_prefetch_buffers(priv);
> +       }
> +
> +       /* Record current mode */
> +       priv->mode_4byte = enable;

How come spi controller decides to flash 4byte mode?

> +}
> +
> +static void bspi_read_via_raf(struct bcmspi_priv *priv, u8 *rx, uint bytes)
> +{
> +       u32 status;
> +       uint words;
> +       int aligned;
> +
> +       /* Flush data from the previous session (unlikely) */
> +       for (;;) {
> +               status = readl(priv->bspi_raf + BSPI_RAF_STATUS_REG);
> +               if (!(status & BSPI_RAF_STATUS_FIFO_EMPTY_MASK)) {
> +                       readl(priv->bspi_raf + BSPI_RAF_READ_DATA_REG);
> +                       continue;
> +               }
> +               if (!(status & BSPI_RAF_STATUS_SESSION_BUSY_MASK))
> +                       break;
> +       }
> +
> +       /* Transfer is in words */
> +       words = (bytes + 3) / 4;
> +
> +       /* Setup hardware */
> +       if (priv->mode_4byte) {
> +               u32 val = priv->bspi_addr & 0xFF000000;
> +
> +               if (val != readl(priv->bspi + BSPI_FLASH_UPPER_ADDR_BYTE_REG)) {
> +                       writel(val,
> +                              priv->bspi + BSPI_FLASH_UPPER_ADDR_BYTE_REG);
> +                       bspi_flush_prefetch_buffers(priv);
> +               }
> +       }
> +       writel(priv->bspi_addr & 0x00FFFFFF,
> +              priv->bspi_raf + BSPI_RAF_START_ADDRESS_REG);
> +       writel(words, priv->bspi_raf + BSPI_RAF_NUM_WORDS_REG);
> +       writel(0, priv->bspi_raf + BSPI_RAF_WATERMARK_REG);

Seems like this driver is handling the flash-specific job in spi
controller which is indeed the wrong implementation. If so, find a
proper way to support this on mtd/spi side?

thanks,
Jagan.


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