[U-Boot] [PATCH v3] Tegra: T210: Add QSPI driver

Jagan Teki jteki at openedev.com
Thu Oct 22 14:23:16 CEST 2015


On 21 October 2015 at 03:01, Tom Warren <twarren at nvidia.com> wrote:
> This is the normal Tegra SPI driver modified to work with the
> QSPI controller in Tegra210. It does not do 2x/4x transfers
> or any other QSPI protocol.

Is it totally different controller, can't we re use existing tegra20*
drivers in any way?

>
> Author: Yen Lin <yelin at nvidia.com>

Better to add this in driver license, unless if you have any specific
notation wrt. nVidia.

> Signed-off-by: Yen Lin <yelin at nvidia.com>
> Signed-off-by: Tom Warren <twarren at nvidia.com>
> ---
> Changes in v2:
> - Drop defconfig and pinmux files, this is a driver-only patch.
> - If/when pinmux tables have been updated for P2371/P2571, another
> - patch will be sent to enable the QSPI driver on those boards.
> Changes in v3:
> - removed status reg write/clear in claim_bus(), done in xfer()
>
>  drivers/spi/Kconfig         |   5 +
>  drivers/spi/Makefile        |   1 +
>  drivers/spi/tegra210_qspi.c | 400 ++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 406 insertions(+)
>  create mode 100644 drivers/spi/tegra210_qspi.c
>
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index 8e04fce..168f31d 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -115,6 +115,11 @@ config TEGRA20_SLINK
>           be used to access the SPI NOR flash on platforms embedding this
>           nVidia Tegra20/Tegra30 IP cores.
>
> +config TEGRA210_QSPI
> +       bool "nVidia Tegra210 QSPI driver"
> +       help
> +         Enable the Tegra Quad-SPI (QSPI) driver for T210.

Add add some more test - at-least 3 lines.

> +
>  config XILINX_SPI
>         bool "Xilinx SPI driver"
>         help
> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
> index de241be..209a41e 100644
> --- a/drivers/spi/Makefile
> +++ b/drivers/spi/Makefile
> @@ -46,6 +46,7 @@ obj-$(CONFIG_SH_QSPI) += sh_qspi.o
>  obj-$(CONFIG_TEGRA114_SPI) += tegra114_spi.o
>  obj-$(CONFIG_TEGRA20_SFLASH) += tegra20_sflash.o
>  obj-$(CONFIG_TEGRA20_SLINK) += tegra20_slink.o
> +obj-$(CONFIG_TEGRA210_QSPI) += tegra210_qspi.o
>  obj-$(CONFIG_TI_QSPI) += ti_qspi.o
>  obj-$(CONFIG_XILINX_SPI) += xilinx_spi.o
>  obj-$(CONFIG_ZYNQ_SPI) += zynq_spi.o
> diff --git a/drivers/spi/tegra210_qspi.c b/drivers/spi/tegra210_qspi.c
> new file mode 100644
> index 0000000..6be37f3
> --- /dev/null
> +++ b/drivers/spi/tegra210_qspi.c
> @@ -0,0 +1,400 @@
> +/*
> + * NVIDIA Tegra210 QSPI controller driver

Space here

> + *  (C) Copyright 2015
> + *  NVIDIA Corporation <www.nvidia.com>

Merge last two into one line.

> + *
> + * SPDX-License-Identifier:     GPL-2.0+
> + */
> +
> +#include <common.h>
> +#include <dm.h>
> +#include <asm/io.h>
> +#include <asm/arch/clock.h>
> +#include <asm/arch-tegra/clk_rst.h>
> +#include <spi.h>
> +#include <fdtdec.h>
> +#include "tegra_spi.h"
> +
> +DECLARE_GLOBAL_DATA_PTR;
> +
> +/* COMMAND1 */
> +#define QSPI_CMD1_GO                   (1 << 31)
> +#define QSPI_CMD1_M_S                  (1 << 30)
> +#define QSPI_CMD1_MODE_MASK            0x3
> +#define QSPI_CMD1_MODE_SHIFT           28
> +#define QSPI_CMD1_CS_SEL_MASK          0x3
> +#define QSPI_CMD1_CS_SEL_SHIFT         26
> +#define QSPI_CMD1_CS_POL_INACTIVE0     (1 << 22)
> +#define QSPI_CMD1_CS_SW_HW             (1 << 21)
> +#define QSPI_CMD1_CS_SW_VAL            (1 << 20)
> +#define QSPI_CMD1_IDLE_SDA_MASK                0x3
> +#define QSPI_CMD1_IDLE_SDA_SHIFT       18
> +#define QSPI_CMD1_BIDIR                        (1 << 17)
> +#define QSPI_CMD1_LSBI_FE              (1 << 16)
> +#define QSPI_CMD1_LSBY_FE              (1 << 15)
> +#define QSPI_CMD1_BOTH_EN_BIT          (1 << 14)
> +#define QSPI_CMD1_BOTH_EN_BYTE         (1 << 13)
> +#define QSPI_CMD1_RX_EN                        (1 << 12)
> +#define QSPI_CMD1_TX_EN                        (1 << 11)
> +#define QSPI_CMD1_PACKED               (1 << 5)
> +#define QSPI_CMD1_BITLEN_MASK          0x1F
> +#define QSPI_CMD1_BITLEN_SHIFT         0
> +
> +/* COMMAND2 */
> +#define QSPI_CMD2_TX_CLK_TAP_DELAY     (1 << 6)
> +#define QSPI_CMD2_TX_CLK_TAP_DELAY_MASK        (0x3F << 6)
> +#define QSPI_CMD2_RX_CLK_TAP_DELAY     (1 << 0)
> +#define QSPI_CMD2_RX_CLK_TAP_DELAY_MASK        (0x3F << 0)
> +
> +/* TRANSFER STATUS */
> +#define QSPI_XFER_STS_RDY              (1 << 30)
> +
> +/* FIFO STATUS */
> +#define QSPI_FIFO_STS_CS_INACTIVE      (1 << 31)
> +#define QSPI_FIFO_STS_FRAME_END                (1 << 30)
> +#define QSPI_FIFO_STS_RX_FIFO_FLUSH    (1 << 15)
> +#define QSPI_FIFO_STS_TX_FIFO_FLUSH    (1 << 14)
> +#define QSPI_FIFO_STS_ERR              (1 << 8)
> +#define QSPI_FIFO_STS_TX_FIFO_OVF      (1 << 7)
> +#define QSPI_FIFO_STS_TX_FIFO_UNR      (1 << 6)
> +#define QSPI_FIFO_STS_RX_FIFO_OVF      (1 << 5)
> +#define QSPI_FIFO_STS_RX_FIFO_UNR      (1 << 4)
> +#define QSPI_FIFO_STS_TX_FIFO_FULL     (1 << 3)
> +#define QSPI_FIFO_STS_TX_FIFO_EMPTY    (1 << 2)
> +#define QSPI_FIFO_STS_RX_FIFO_FULL     (1 << 1)
> +#define QSPI_FIFO_STS_RX_FIFO_EMPTY    (1 << 0)
> +
> +#define QSPI_TIMEOUT           1000
> +
> +struct qspi_regs {
> +       u32 command1;   /* 000:QSPI_COMMAND1 register */
> +       u32 command2;   /* 004:QSPI_COMMAND2 register */
> +       u32 timing1;    /* 008:QSPI_CS_TIM1 register */
> +       u32 timing2;    /* 00c:QSPI_CS_TIM2 register */
> +       u32 xfer_status;/* 010:QSPI_TRANS_STATUS register */
> +       u32 fifo_status;/* 014:QSPI_FIFO_STATUS register */
> +       u32 tx_data;    /* 018:QSPI_TX_DATA register */
> +       u32 rx_data;    /* 01c:QSPI_RX_DATA register */
> +       u32 dma_ctl;    /* 020:QSPI_DMA_CTL register */
> +       u32 dma_blk;    /* 024:QSPI_DMA_BLK register */
> +       u32 rsvd[56];   /* 028-107 reserved */
> +       u32 tx_fifo;    /* 108:QSPI_FIFO1 register */
> +       u32 rsvd2[31];  /* 10c-187 reserved */
> +       u32 rx_fifo;    /* 188:QSPI_FIFO2 register */
> +       u32 spare_ctl;  /* 18c:QSPI_SPARE_CTRL register */
> +};
> +
> +struct tegra210_qspi_priv {
> +       struct qspi_regs *regs;
> +       unsigned int freq;
> +       unsigned int mode;
> +       int periph_id;
> +       int valid;
> +       int last_transaction_us;
> +};
> +
> +static int tegra210_qspi_ofdata_to_platdata(struct udevice *bus)
> +{
> +       struct tegra_spi_platdata *plat = bus->platdata;
> +       const void *blob = gd->fdt_blob;
> +       int node = bus->of_offset;
> +
> +       plat->base = dev_get_addr(bus);
> +       plat->periph_id = clock_decode_periph_id(blob, node);
> +
> +       if (plat->periph_id == PERIPH_ID_NONE) {
> +               debug("%s: could not decode periph id %d\n", __func__,
> +                     plat->periph_id);
> +               return -FDT_ERR_NOTFOUND;
> +       }
> +
> +       /* Use 500KHz as a suitable default */
> +       plat->frequency = fdtdec_get_int(blob, node, "spi-max-frequency",
> +                                       500000);
> +       plat->deactivate_delay_us = fdtdec_get_int(blob, node,
> +                                       "spi-deactivate-delay", 0);
> +       debug("%s: base=%#08lx, periph_id=%d, max-frequency=%d, deactivate_delay=%d\n",
> +             __func__, plat->base, plat->periph_id, plat->frequency,
> +             plat->deactivate_delay_us);
> +
> +       return 0;
> +}
> +
> +static int tegra210_qspi_probe(struct udevice *bus)
> +{
> +       struct tegra_spi_platdata *plat = dev_get_platdata(bus);
> +       struct tegra210_qspi_priv *priv = dev_get_priv(bus);
> +
> +       priv->regs = (struct qspi_regs *)plat->base;
> +
> +       priv->last_transaction_us = timer_get_us();
> +       priv->freq = plat->frequency;
> +       priv->periph_id = plat->periph_id;
> +
> +       return 0;
> +}
> +
> +static int tegra210_qspi_claim_bus(struct udevice *bus)
> +{
> +       struct tegra210_qspi_priv *priv = dev_get_priv(bus);
> +       struct qspi_regs *regs = priv->regs;
> +
> +       /* Change SPI clock to correct frequency, PLLP_OUT0 source */
> +       clock_start_periph_pll(priv->periph_id, CLOCK_ID_PERIPH, priv->freq);
> +
> +       debug("%s: FIFO STATUS = %08x\n", __func__, readl(&regs->fifo_status));
> +
> +       /* Set master mode and sw controlled CS */
> +       setbits_le32(&regs->command1, QSPI_CMD1_M_S | QSPI_CMD1_CS_SW_HW |
> +                    (priv->mode << QSPI_CMD1_MODE_SHIFT));
> +       debug("%s: COMMAND1 = %08x\n", __func__, readl(&regs->command1));
> +
> +       return 0;
> +}
> +
> +/**
> + * Activate the CS by driving it LOW
> + *
> + * @param slave        Pointer to spi_slave to which controller has to
> + *             communicate with
> + */
> +static void spi_cs_activate(struct udevice *dev)
> +{
> +       struct udevice *bus = dev->parent;
> +       struct tegra_spi_platdata *pdata = dev_get_platdata(bus);
> +       struct tegra210_qspi_priv *priv = dev_get_priv(bus);
> +
> +       /* If it's too soon to do another transaction, wait */
> +       if (pdata->deactivate_delay_us &&
> +           priv->last_transaction_us) {
> +               ulong delay_us;         /* The delay completed so far */
> +               delay_us = timer_get_us() - priv->last_transaction_us;
> +               if (delay_us < pdata->deactivate_delay_us)
> +                       udelay(pdata->deactivate_delay_us - delay_us);
> +       }
> +
> +       clrbits_le32(&priv->regs->command1, QSPI_CMD1_CS_SW_VAL);
> +}
> +
> +/**
> + * Deactivate the CS by driving it HIGH
> + *
> + * @param slave        Pointer to spi_slave to which controller has to
> + *             communicate with
> + */
> +static void spi_cs_deactivate(struct udevice *dev)
> +{
> +       struct udevice *bus = dev->parent;
> +       struct tegra_spi_platdata *pdata = dev_get_platdata(bus);
> +       struct tegra210_qspi_priv *priv = dev_get_priv(bus);
> +
> +       setbits_le32(&priv->regs->command1, QSPI_CMD1_CS_SW_VAL);
> +
> +       /* Remember time of this transaction so we can honour the bus delay */
> +       if (pdata->deactivate_delay_us)
> +               priv->last_transaction_us = timer_get_us();
> +
> +       debug("Deactivate CS, bus '%s'\n", bus->name);
> +}
> +
> +static int tegra210_qspi_xfer(struct udevice *dev, unsigned int bitlen,
> +                            const void *data_out, void *data_in,
> +                            unsigned long flags)
> +{
> +       struct udevice *bus = dev->parent;
> +       struct tegra210_qspi_priv *priv = dev_get_priv(bus);
> +       struct qspi_regs *regs = priv->regs;
> +       u32 reg, tmpdout, tmpdin = 0;
> +       const u8 *dout = data_out;
> +       u8 *din = data_in;
> +       int num_bytes;
> +       int ret;
> +
> +       debug("%s: slave %u:%u dout %p din %p bitlen %u\n",
> +             __func__, bus->seq, spi_chip_select(dev), dout, din, bitlen);
> +       if (bitlen % 8)
> +               return -1;
> +       num_bytes = bitlen / 8;
> +
> +       ret = 0;
> +
> +       /* clear all error status bits */
> +       reg = readl(&regs->fifo_status);
> +       writel(reg, &regs->fifo_status);
> +
> +       /* flush RX/TX FIFOs */
> +       setbits_le32(&regs->fifo_status,
> +                    (QSPI_FIFO_STS_RX_FIFO_FLUSH |
> +                     QSPI_FIFO_STS_TX_FIFO_FLUSH));
> +       while ((readl(&regs->fifo_status) &
> +                     (QSPI_FIFO_STS_RX_FIFO_FLUSH |
> +                      QSPI_FIFO_STS_TX_FIFO_FLUSH)))
> +               ;

May we can do this flush fifo check on claim_bus. if something goes in
while it may return there instead of xfer for each consecutive
transfers can lock. And also please use proper timeout check instead
of while with semicolon.

> +
> +       /*
> +        * Notes:
> +        *   1. don't set LSBY_FE, so no need to swap bytes from/to TX/RX FIFOs;
> +        *   2. don't set RX_EN and TX_EN yet.
> +        *      (SW needs to make sure that while programming the blk_size,
> +        *       tx_en and rx_en bits must be zero)
> +        *      [TODO] I (Yen Lin) have problems when both RX/TX EN bits are set
> +        *             i.e., both dout and din are not NULL.
> +        */
> +       clrsetbits_le32(&regs->command1,
> +                       (QSPI_CMD1_LSBI_FE | QSPI_CMD1_LSBY_FE |
> +                        QSPI_CMD1_RX_EN | QSPI_CMD1_TX_EN),
> +                       (spi_chip_select(dev) << QSPI_CMD1_CS_SEL_SHIFT));
> +
> +       /* set xfer size to 1 block (32 bits) */
> +       writel(0, &regs->dma_blk);
> +
> +       if (flags & SPI_XFER_BEGIN)
> +               spi_cs_activate(dev);
> +
> +       /* handle data in 32-bit chunks */
> +       while (num_bytes > 0) {
> +               int bytes;
> +               int tm;
> +
> +               tmpdout = 0;
> +               bytes = (num_bytes > 4) ?  4 : num_bytes;
> +
> +               if (dout != NULL) {
> +                       memcpy((void *)&tmpdout, (void *)dout, bytes);
> +                       dout += bytes;
> +                       num_bytes -= bytes;
> +                       writel(tmpdout, &regs->tx_fifo);
> +                       setbits_le32(&regs->command1, QSPI_CMD1_TX_EN);
> +               }
> +
> +               if (din != NULL)
> +                       setbits_le32(&regs->command1, QSPI_CMD1_RX_EN);
> +
> +               /* clear ready bit */
> +               setbits_le32(&regs->xfer_status, QSPI_XFER_STS_RDY);
> +
> +               clrsetbits_le32(&regs->command1,
> +                               QSPI_CMD1_BITLEN_MASK << QSPI_CMD1_BITLEN_SHIFT,
> +                               (bytes * 8 - 1) << QSPI_CMD1_BITLEN_SHIFT);
> +               /* Need to stabilize other reg bit before GO bit set */
> +               udelay(2);
> +               setbits_le32(&regs->command1, QSPI_CMD1_GO);
> +               udelay(1);

Can we do any timeout check's instead of these numerical udelay's.

> +
> +               /*
> +                * Wait for SPI transmit FIFO to empty, or to time out.
> +                * The RX FIFO status will be read and cleared last
> +                */
> +               for (tm = 0; tm < QSPI_TIMEOUT; ++tm) {
> +                       u32 fifo_status, xfer_status;
> +
> +                       xfer_status = readl(&regs->xfer_status);
> +                       if (!(xfer_status & QSPI_XFER_STS_RDY))
> +                               continue;
> +
> +                       fifo_status = readl(&regs->fifo_status);
> +                       if (fifo_status & QSPI_FIFO_STS_ERR) {
> +                               debug("%s: got a fifo error: ", __func__);
> +                               if (fifo_status & QSPI_FIFO_STS_TX_FIFO_OVF)
> +                                       debug("tx FIFO overflow ");
> +                               if (fifo_status & QSPI_FIFO_STS_TX_FIFO_UNR)
> +                                       debug("tx FIFO underrun ");
> +                               if (fifo_status & QSPI_FIFO_STS_RX_FIFO_OVF)
> +                                       debug("rx FIFO overflow ");
> +                               if (fifo_status & QSPI_FIFO_STS_RX_FIFO_UNR)
> +                                       debug("rx FIFO underrun ");
> +                               if (fifo_status & QSPI_FIFO_STS_TX_FIFO_FULL)
> +                                       debug("tx FIFO full ");
> +                               if (fifo_status & QSPI_FIFO_STS_TX_FIFO_EMPTY)
> +                                       debug("tx FIFO empty ");
> +                               if (fifo_status & QSPI_FIFO_STS_RX_FIFO_FULL)
> +                                       debug("rx FIFO full ");
> +                               if (fifo_status & QSPI_FIFO_STS_RX_FIFO_EMPTY)
> +                                       debug("rx FIFO empty ");
> +                               debug("\n");
> +                               break;
> +                       }
> +
> +                       if (!(fifo_status & QSPI_FIFO_STS_RX_FIFO_EMPTY)) {
> +                               tmpdin = readl(&regs->rx_fifo);
> +                               if (din != NULL) {
> +                                       memcpy(din, &tmpdin, bytes);
> +                                       din += bytes;
> +                                       num_bytes -= bytes;
> +                               }
> +                       }
> +                       break;
> +               }
> +
> +               if (tm >= QSPI_TIMEOUT)
> +                       ret = tm;
> +
> +               /* clear ACK RDY, etc. bits */
> +               writel(readl(&regs->fifo_status), &regs->fifo_status);
> +       }

I think this rx logic looks similar to existing tegra20 drivers.

Honestly, this look quite uneasy for me, the code looks fine on the
implementation perspective no comment on that - but what if you
separate the code for  (drivers/spi/zynq_spi.c)
- checking TX fifo empty with timeout and
- then read the rx fifo (timeout couldn't need here)

> +
> +       if (flags & SPI_XFER_END)
> +               spi_cs_deactivate(dev);
> +
> +       debug("%s: transfer ended. Value=%08x, fifo_status = %08x\n",
> +             __func__, tmpdin, readl(&regs->fifo_status));
> +
> +       if (ret) {
> +               printf("%s: timeout during SPI transfer, tm %d\n",
> +                      __func__, ret);
> +               return -1;
> +       }
> +
> +       return ret;
> +}
> +
> +static int tegra210_qspi_set_speed(struct udevice *bus, uint speed)
> +{
> +       struct tegra_spi_platdata *plat = bus->platdata;
> +       struct tegra210_qspi_priv *priv = dev_get_priv(bus);
> +
> +       if (speed > plat->frequency)
> +               speed = plat->frequency;
> +       priv->freq = speed;
> +       debug("%s: regs=%p, speed=%d\n", __func__, priv->regs, priv->freq);
> +
> +       return 0;
> +}
> +
> +static int tegra210_qspi_set_mode(struct udevice *bus, uint mode)
> +{
> +       struct tegra210_qspi_priv *priv = dev_get_priv(bus);
> +
> +       priv->mode = mode;
> +       debug("%s: regs=%p, mode=%d\n", __func__, priv->regs, priv->mode);
> +
> +       return 0;
> +}
> +
> +static const struct dm_spi_ops tegra210_qspi_ops = {
> +       .claim_bus      = tegra210_qspi_claim_bus,
> +       .xfer           = tegra210_qspi_xfer,
> +       .set_speed      = tegra210_qspi_set_speed,
> +       .set_mode       = tegra210_qspi_set_mode,
> +       /*
> +        * cs_info is not needed, since we require all chip selects to be
> +        * in the device tree explicitly
> +        */
> +};
> +
> +static const struct udevice_id tegra210_qspi_ids[] = {
> +       { .compatible = "nvidia,tegra210-qspi" },
> +       { }
> +};
> +
> +U_BOOT_DRIVER(tegra210_qspi) = {
> +       .name = "tegra210-qspi",
> +       .id = UCLASS_SPI,
> +       .of_match = tegra210_qspi_ids,
> +       .ops = &tegra210_qspi_ops,
> +       .ofdata_to_platdata = tegra210_qspi_ofdata_to_platdata,
> +       .platdata_auto_alloc_size = sizeof(struct tegra_spi_platdata),
> +       .priv_auto_alloc_size = sizeof(struct tegra210_qspi_priv),
> +       .per_child_auto_alloc_size = sizeof(struct spi_slave),
> +       .probe = tegra210_qspi_probe,
> +};

-- Jagan.


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