[U-Boot] [PATCH v3 2/5] spi: add spi-mem driver for MediaTek MT7629 SoC

Vignesh Raghavendra vigneshr at ti.com
Fri Jun 14 04:56:35 UTC 2019



On 12/06/19 9:26 PM, Jagan Teki wrote:
> + Vignesh
> 
> On Tue, May 14, 2019 at 7:11 AM Weijie Gao <weijie.gao at mediatek.com> wrote:
>>
>> This patch adds spi-mem driver for MediaTek MT7629 SoC to access SPI-NOR
>> and SPI-NAND flashes.
>>
>> Cc: Jagan Teki <jagan at openedev.com>
>> Signed-off-by: Weijie Gao <weijie.gao at mediatek.com>
>> ---
>> Changes since v1: rename mtk_spimem to spi_snfi_spi. change pinctrl name.
>> Changes since v2: remove udevice in mtk_snfi_priv.
>> ---
>>  drivers/spi/Kconfig        |   9 ++
>>  drivers/spi/Makefile       |   1 +
>>  drivers/spi/mtk_snfi_spi.c | 321 +++++++++++++++++++++++++++++++++++++
>>  3 files changed, 331 insertions(+)
>>  create mode 100644 drivers/spi/mtk_snfi_spi.c
>>
>> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
>> index 4f0f5d99953..8b6e0fb2d99 100644
>> --- a/drivers/spi/Kconfig
>> +++ b/drivers/spi/Kconfig
>> @@ -139,6 +139,15 @@ config MT7621_SPI
>>           the SPI NOR flash on platforms embedding this Ralink / MediaTek
>>           SPI core, like MT7621/7628/7688.
>>
>> +config MTK_SNFI_SPI
>> +       bool "Mediatek SPI memory controller driver"
>> +       depends on SPI_MEM
>> +       help
>> +         Enable the Mediatek SPI memory controller driver. This driver is
>> +         originally based on the MediaTek SNFI IP core. It can only be
>> +         used to access SPI memory devices like SPI-NOR or SPI-NAND on
>> +         platforms embedding this IP core, like MT7622/M7629.
>> +
>>  config MVEBU_A3700_SPI
>>         bool "Marvell Armada 3700 SPI driver"
>>         select CLK_ARMADA_3720
>> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
>> index f1e3becd2b7..5c639634777 100644
>> --- a/drivers/spi/Makefile
>> +++ b/drivers/spi/Makefile
>> @@ -36,6 +36,7 @@ obj-$(CONFIG_LPC32XX_SSP) += lpc32xx_ssp.o
>>  obj-$(CONFIG_MESON_SPIFC) += meson_spifc.o
>>  obj-$(CONFIG_MPC8XX_SPI) += mpc8xx_spi.o
>>  obj-$(CONFIG_MPC8XXX_SPI) += mpc8xxx_spi.o
>> +obj-$(CONFIG_MTK_SNFI_SPI) += mtk_snfi_spi.o
>>  obj-$(CONFIG_MT7621_SPI) += mt7621_spi.o
>>  obj-$(CONFIG_MSCC_BB_SPI) += mscc_bb_spi.o
>>  obj-$(CONFIG_MVEBU_A3700_SPI) += mvebu_a3700_spi.o
>> diff --git a/drivers/spi/mtk_snfi_spi.c b/drivers/spi/mtk_snfi_spi.c
>> new file mode 100644
>> index 00000000000..0adc734a5c1
>> --- /dev/null
>> +++ b/drivers/spi/mtk_snfi_spi.c
>> @@ -0,0 +1,321 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +/*
>> + * Copyright (C) 2019 MediaTek Inc. All Rights Reserved.
>> + *
>> + * Author: Weijie Gao <weijie.gao at mediatek.com>
>> + */
>> +
>> +#include <common.h>
>> +#include <clk.h>
>> +#include <dm.h>
>> +#include <errno.h>
>> +#include <spi.h>
>> +#include <spi-mem.h>
>> +#include <stdbool.h>
>> +#include <dm/pinctrl.h>
>> +#include <linux/bitops.h>
>> +#include <linux/io.h>
>> +#include <linux/iopoll.h>
>> +
>> +#define SNFI_MAC_CTL                   0x500
>> +#define MAC_XIO_SEL                    BIT(4)
>> +#define SF_MAC_EN                      BIT(3)
>> +#define SF_TRIG                                BIT(2)
>> +#define WIP_READY                      BIT(1)
>> +#define WIP                            BIT(0)
>> +
>> +#define SNFI_MAC_OUTL                  0x504
>> +#define SNFI_MAC_INL                   0x508
>> +
>> +#define SNFI_MISC_CTL                  0x538
>> +#define SW_RST                         BIT(28)
>> +#define FIFO_RD_LTC_SHIFT              25
>> +#define FIFO_RD_LTC                    GENMASK(26, 25)
>> +#define LATCH_LAT_SHIFT                        8
>> +#define LATCH_LAT                      GENMASK(9, 8)
>> +#define CS_DESELECT_CYC_SHIFT          0
>> +#define CS_DESELECT_CYC                        GENMASK(4, 0)
>> +
>> +#define SNF_STA_CTL1                   0x550
>> +#define SPI_STATE                      GENMASK(3, 0)
>> +
>> +#define SNFI_GPRAM_OFFSET              0x800
>> +#define SNFI_GPRAM_SIZE                        0x80
>> +
>> +#define SNFI_POLL_INTERVAL             500000
>> +#define SNFI_RST_POLL_INTERVAL         1000000
>> +
>> +struct mtk_snfi_priv {
>> +       void __iomem *base;
>> +
>> +       struct clk nfi_clk;
>> +       struct clk pad_clk;
>> +};
>> +
>> +static int mtk_snfi_adjust_op_size(struct spi_slave *slave,
>> +                                  struct spi_mem_op *op)
>> +{
>> +       u32 nbytes;
>> +
>> +       /*
>> +        * When there is input data, it will be appended after the output
>> +        * data in the GPRAM. So the total size of either pure output data
>> +        * or the output+input data must not exceed the GPRAM size.
>> +        */
>> +
>> +       nbytes = sizeof(op->cmd.opcode) + op->addr.nbytes +
>> +               op->dummy.nbytes;
>> +
>> +       if (nbytes + op->data.nbytes <= SNFI_GPRAM_SIZE)
>> +               return 0;
>> +
>> +       if (nbytes >= SNFI_GPRAM_SIZE)
>> +               return -ENOTSUPP;
>> +
>> +       op->data.nbytes = SNFI_GPRAM_SIZE - nbytes;
>> +
>> +       return 0;
>> +}
>> +
>> +static bool mtk_snfi_supports_op(struct spi_slave *slave,
>> +                                const struct spi_mem_op *op)
>> +{
>> +       if (op->cmd.buswidth > 1 || op->addr.buswidth > 1 ||
>> +           op->dummy.buswidth > 1 || op->data.buswidth > 1)
>> +               return false;
>> +
>> +       return true;
>> +}
>> +
>> +static int mtk_snfi_mac_trigger(struct mtk_snfi_priv *priv,
>> +                               struct udevice *bus, u32 outlen, u32 inlen)
>> +{
>> +       int ret;
>> +       u32 val;
>> +
>> +#ifdef CONFIG_PINCTRL
>> +       pinctrl_select_state(bus, "snfi");
>> +#endif
>> +
>> +       writel(SF_MAC_EN, priv->base + SNFI_MAC_CTL);
>> +       writel(outlen, priv->base + SNFI_MAC_OUTL);
>> +       writel(inlen, priv->base + SNFI_MAC_INL);
>> +
>> +       writel(SF_MAC_EN | SF_TRIG, priv->base + SNFI_MAC_CTL);
>> +
>> +       ret = readl_poll_timeout(priv->base + SNFI_MAC_CTL, val,
>> +                                val & WIP_READY, SNFI_POLL_INTERVAL);
>> +       if (ret) {
>> +               printf("%s: timed out waiting for WIP_READY\n", __func__);
>> +               goto cleanup;
>> +       }
>> +
>> +       ret = readl_poll_timeout(priv->base + SNFI_MAC_CTL, val,
>> +                                !(val & WIP), SNFI_POLL_INTERVAL);
>> +       if (ret)
>> +               printf("%s: timed out waiting for WIP cleared\n", __func__);
>> +
>> +       writel(0, priv->base + SNFI_MAC_CTL);
>> +
>> +cleanup:
>> +#ifdef CONFIG_PINCTRL
>> +       pinctrl_select_state(bus, "default");
>> +#endif
>> +
>> +       return ret;
>> +}
>> +
>> +static int mtk_snfi_mac_reset(struct mtk_snfi_priv *priv)
>> +{
>> +       int ret;
>> +       u32 val;
>> +
>> +       setbits_32(priv->base + SNFI_MISC_CTL, SW_RST);
>> +
>> +       ret = readl_poll_timeout(priv->base + SNF_STA_CTL1, val,
>> +                                !(val & SPI_STATE), SNFI_POLL_INTERVAL);
>> +       if (ret)
>> +               printf("%s: failed to reset snfi mac\n", __func__);
>> +
>> +       writel((2 << FIFO_RD_LTC_SHIFT) |
>> +               (10 << CS_DESELECT_CYC_SHIFT),
>> +               priv->base + SNFI_MISC_CTL);
>> +
>> +       return ret;
>> +}
>> +
>> +static void mtk_snfi_copy_to_gpram(struct mtk_snfi_priv *priv,
>> +                                  const void *data, size_t len)
>> +{
>> +       void __iomem *gpram = priv->base + SNFI_GPRAM_OFFSET;
>> +       size_t i, n = (len + sizeof(u32) - 1) / sizeof(u32);
>> +       const u32 *buff = data;
>> +
>> +       /*
>> +        * The output data will always be copied to the beginning of
>> +        * the GPRAM. Uses word write for better performace.
>> +        *
>> +        * Trailing bytes in the last word are not cared.
>> +        */
>> +
>> +       for (i = 0; i < n; i++)
>> +               writel(buff[i], gpram + i * sizeof(u32));
>> +}
>> +
>> +static void mtk_snfi_copy_from_gpram(struct mtk_snfi_priv *priv,
>> +                                    void *data, size_t pos, size_t len)
>> +{
>> +       void __iomem *gpram = priv->base + SNFI_GPRAM_OFFSET;
>> +       u8 gpdata[SNFI_GPRAM_SIZE];
>> +       u32 *buff = (u32 *)gpdata;
>> +       size_t i, off, end;
>> +
>> +       /* Start position in the buffer */
>> +       off = pos & (sizeof(u32) - 1);
>> +
>> +       /* End position for copy */
>> +       end = (len + pos + sizeof(u32) - 1) & (~(sizeof(u32) - 1));
>> +
>> +       /* Start position for copy */
>> +       pos &= ~(sizeof(u32) - 1);
>> +
>> +       /*
>> +        * Read aligned data from GPRAM to buffer first.
>> +        * Uses word read for better performace.
>> +        */
>> +       i = 0;
>> +       while (pos < end) {
>> +               buff[i++] = readl(gpram + pos);
>> +               pos += sizeof(u32);
>> +       }
>> +
>> +       /* Copy real data */
>> +       memcpy(data, gpdata + off, len);
>> +}
>> +
>> +static int mtk_snfi_exec_op(struct spi_slave *slave,
>> +                           const struct spi_mem_op *op)
>> +{
>> +       struct udevice *bus = dev_get_parent(slave->dev);
>> +       struct mtk_snfi_priv *priv = dev_get_priv(bus);
>> +       u8 gpram_data[SNFI_GPRAM_SIZE];
>> +       u32 i, len = 0, inlen = 0;
>> +       int addr_sh;
>> +       int ret;
>> +
>> +       ret = mtk_snfi_mac_reset(priv);
>> +       if (ret)
>> +               return ret;
>> +
>> +       /* Put opcode */
>> +       gpram_data[len++] = op->cmd.opcode;
>> +
>> +       /* Put address */
>> +       addr_sh = (op->addr.nbytes - 1) * 8;
>> +       while (addr_sh >= 0) {
>> +               gpram_data[len++] = (op->addr.val >> addr_sh) & 0xff;
>> +               addr_sh -= 8;
>> +       }
>> +
>> +       /* Put dummy bytes */
>> +       for (i = 0; i < op->dummy.nbytes; i++)
>> +               gpram_data[len++] = 0;
>> +
>> +       /* Put output data */
>> +       if (op->data.nbytes && op->data.dir == SPI_MEM_DATA_OUT) {
>> +               memcpy(gpram_data + len, op->data.buf.out, op->data.nbytes);
>> +               len += op->data.nbytes;
>> +       }
>> +
>> +       /* Copy final output data to GPRAM */
>> +       mtk_snfi_copy_to_gpram(priv, gpram_data, len);
>> +
>> +       /* Start one SPI transaction */
>> +       if (op->data.nbytes && op->data.dir == SPI_MEM_DATA_IN)
>> +               inlen = op->data.nbytes;
>> +
>> +       ret = mtk_snfi_mac_trigger(priv, bus, len, inlen);
>> +       if (ret)
>> +               return ret;
>> +
>> +       /* Copy input data from GPRAM */
>> +       if (inlen)
>> +               mtk_snfi_copy_from_gpram(priv, op->data.buf.in, len, inlen);
>> +
>> +       return 0;
>> +}
>> +
>> +static int mtk_snfi_spi_probe(struct udevice *bus)
>> +{
>> +       struct mtk_snfi_priv *priv = dev_get_priv(bus);
>> +       int ret;
>> +
>> +       priv->base = (void __iomem *)devfdt_get_addr(bus);
>> +       if (!priv->base)
>> +               return -EINVAL;
>> +
>> +       ret = clk_get_by_name(bus, "nfi_clk", &priv->nfi_clk);
>> +       if (ret < 0)
>> +               return ret;
>> +
>> +       ret = clk_get_by_name(bus, "pad_clk", &priv->pad_clk);
>> +       if (ret < 0)
>> +               return ret;
>> +
>> +       clk_enable(&priv->nfi_clk);
>> +       clk_enable(&priv->pad_clk);
>> +
>> +       return 0;
>> +}
>> +
>> +static int mtk_snfi_set_speed(struct udevice *bus, uint speed)
>> +{
>> +       return 0;
>> +}
>> +
>> +static int mtk_snfi_set_mode(struct udevice *bus, uint mode)
>> +{
>> +       if (mode)
>> +               return -EINVAL;
>> +
>> +       return 0;
>> +}
> 
> What does this mean? can't handle mode from command?
> 
>> +
>> +static int mtk_snfi_child_pre_probe(struct udevice *dev)
>> +{
>> +       struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
> 
> We usually does this in xfer. If mem_ops would handle udevice instead
> of spi_slave, this wouldn't need anymore. have you tried this way?
> 

Quoting the snipped code:

>> +	if (plat->cs > 0) {
>> +		printf("%s: invalid chip select %u\n", __func__, plat->cs);
>> +		return -ENODEV;
>> +	}
>> +

I think this is generic check and can be moved SPI core. 
Could you move this to spi_child_pre_probe()? 

Please add a field to dm_spi_bus to store number of CS supported by SPI controller
and use it to check against slave CS.
For backward compatibility, ignore if field is 0.

-- 
Regards
Vignesh


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