[U-Boot] [PATCH v4 1/4] dm: spi: add BCM63xx HSSPI driver
Jagan Teki
jagannadh.teki at gmail.com
Fri Aug 11 09:42:19 UTC 2017
On Sun, Jul 30, 2017 at 5:44 PM, Álvaro Fernández Rojas
<noltari at gmail.com> wrote:
> This driver is a simplified version of linux/drivers/spi/spi-bcm63xx-hsspi.c
>
> Signed-off-by: Álvaro Fernández Rojas <noltari at gmail.com>
> Reviewed-by: Simon Glass <sjg at chromium.org>
> Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck at gmail.com>
> ---
> v4: no changes.
> v3: Switch to CONFIG_BCM63XX_HSSPI and rebase on top of SPI v4.
> v2: Introduce changes suggested by Simon Glass:
> - Split bcm63xx_hsspi_xfer() into smaller functions.
> - Check possible clock errors.
> - Check possible reset errors.
> - Switch to devfdt_get_addr_size_index().
> - Use setbits32_be() for clock gate.
>
> drivers/spi/Kconfig | 8 +
> drivers/spi/Makefile | 1 +
> drivers/spi/bcm63xx_hsspi.c | 413 ++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 422 insertions(+)
> create mode 100644 drivers/spi/bcm63xx_hsspi.c
>
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index 511643607b..97c3cb6103 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -40,6 +40,14 @@ config ATMEL_SPI
> many AT91 (ARM) chips. This driver can be used to access
> the SPI Flash, such as AT25DF321.
>
> +config BCM63XX_HSSPI
> + bool "BCM63XX HSSPI driver"
> + depends on ARCH_BMIPS
> + help
> + Enable the BCM6328 HSSPI driver. This driver can be used to
> + access the SPI NOR flash on platforms embedding this Broadcom
> + SPI core.
> +
> config BCM63XX_SPI
> bool "BCM6348 SPI driver"
> depends on ARCH_BMIPS
> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
> index d9802dd8c3..fefafbe333 100644
> --- a/drivers/spi/Makefile
> +++ b/drivers/spi/Makefile
> @@ -19,6 +19,7 @@ obj-$(CONFIG_ALTERA_SPI) += altera_spi.o
> obj-$(CONFIG_ATH79_SPI) += ath79_spi.o
> obj-$(CONFIG_ATMEL_DATAFLASH_SPI) += atmel_dataflash_spi.o
> obj-$(CONFIG_ATMEL_SPI) += atmel_spi.o
> +obj-$(CONFIG_BCM63XX_HSSPI) += bcm63xx_hsspi.o
> obj-$(CONFIG_BCM63XX_SPI) += bcm63xx_spi.o
> obj-$(CONFIG_CADENCE_QSPI) += cadence_qspi.o cadence_qspi_apb.o
> obj-$(CONFIG_CF_SPI) += cf_spi.o
> diff --git a/drivers/spi/bcm63xx_hsspi.c b/drivers/spi/bcm63xx_hsspi.c
> new file mode 100644
> index 0000000000..538c4ec4fe
> --- /dev/null
> +++ b/drivers/spi/bcm63xx_hsspi.c
> @@ -0,0 +1,413 @@
> +/*
> + * Copyright (C) 2017 Álvaro Fernández Rojas <noltari at gmail.com>
> + *
> + * Derived from linux/drivers/spi/spi-bcm63xx-hsspi.c:
> + * Copyright (C) 2000-2010 Broadcom Corporation
> + * Copyright (C) 2012-2013 Jonas Gorski <jogo at openwrt.org>
> + *
> + * SPDX-License-Identifier: GPL-2.0+
> + */
> +
> +#include <common.h>
> +#include <clk.h>
> +#include <dm.h>
> +#include <spi.h>
> +#include <reset.h>
> +#include <asm/io.h>
> +
> +DECLARE_GLOBAL_DATA_PTR;
> +
> +#define SPI_PP_SEL 0
> +
> +#define SPI_MAX_SYNC_CLOCK 30000000
> +
> +/* SPI Control register */
> +#define SPI_CTL_REG 0x000
> +#define SPI_CTL_CS_POL_SHIFT 0
> +#define SPI_CTL_CS_POL_MASK (0xff << SPI_CTL_CS_POL_SHIFT)
> +#define SPI_CTL_CLK_GATE_SHIFT 16
> +#define SPI_CTL_CLK_GATE_MASK (1 << SPI_CTL_CLK_GATE_SHIFT)
> +#define SPI_CTL_CLK_POL_SHIFT 17
> +#define SPI_CTL_CLK_POL_MASK (1 << SPI_CTL_CLK_POL_SHIFT)
> +
> +/* SPI Interrupts registers */
> +#define SPI_IR_STAT_REG 0x008
> +#define SPI_IR_ST_MASK_REG 0x00c
> +#define SPI_IR_MASK_REG 0x010
> +
> +#define SPI_IR_CLEAR_ALL 0xff001f1f
> +
> +/* SPI Ping-Pong Command registers */
> +#define SPI_PP_CMD_REG (0x080 + (0x40 * (SPI_PP_SEL)) + 0x00)
> +#define SPI_PP_CMD_OP_SHIFT 0
> +#define SPI_PP_CMD_OP_START (0x1 << SPI_PP_CMD_OP_SHIFT)
> +#define SPI_PP_CMD_PFL_SHIFT 8
> +#define SPI_PP_CMD_PFL_MASK (0x7 << SPI_PP_CMD_PFL_SHIFT)
> +#define SPI_PP_CMD_SLAVE_SHIFT 12
> +#define SPI_PP_CMD_SLAVE_MASK (0x7 << SPI_PP_CMD_SLAVE_SHIFT)
> +
> +/* SPI Ping-Pong Status registers */
> +#define SPI_PP_STAT_REG (0x080 + (0x40 * (SPI_PP_SEL)) + 0x04)
> +#define SPI_PP_STAT_SRCBUSY_SHIFT 1
> +#define SPI_PP_STAT_SRCBUSY_MASK (1 << SPI_PP_STAT_SRCBUSY_SHIFT)
> +
> +/* SPI Profile Clock registers */
> +#define SPI_PFL_CLK_REG(x) (0x100 + (0x20 * (x)) + 0x00)
> +#define SPI_PFL_CLK_FREQ_SHIFT 0
> +#define SPI_PFL_CLK_FREQ_MASK (0x3fff << SPI_PFL_CLK_FREQ_SHIFT)
> +#define SPI_PFL_CLK_RSTLOOP_SHIFT 15
> +#define SPI_PFL_CLK_RSTLOOP_MASK (1 << SPI_PFL_CLK_RSTLOOP_SHIFT)
> +
> +/* SPI Profile Signal registers */
> +#define SPI_PFL_SIG_REG(x) (0x100 + (0x20 * (x)) + 0x04)
> +#define SPI_PFL_SIG_LATCHRIS_SHIFT 12
> +#define SPI_PFL_SIG_LATCHRIS_MASK (1 << SPI_PFL_SIG_LATCHRIS_SHIFT)
> +#define SPI_PFL_SIG_LAUNCHRIS_SHIFT 13
> +#define SPI_PFL_SIG_LAUNCHRIS_MASK (1 << SPI_PFL_SIG_LAUNCHRIS_SHIFT)
> +#define SPI_PFL_SIG_ASYNCIN_SHIFT 16
> +#define SPI_PFL_SIG_ASYNCIN_MASK (1 << SPI_PFL_SIG_ASYNCIN_SHIFT)
> +
> +/* SPI Profile Mode registers */
> +#define SPI_PFL_MODE_REG(x) (0x100 + (0x20 * (x)) + 0x08)
> +#define SPI_PFL_MODE_FILL_SHIFT 0
> +#define SPI_PFL_MODE_FILL_MASK (0xff << SPI_PFL_MODE_FILL_SHIFT)
> +#define SPI_PFL_MODE_MDRDSZ_SHIFT 16
> +#define SPI_PFL_MODE_MDRDSZ_MASK (1 << SPI_PFL_MODE_MDRDSZ_SHIFT)
> +#define SPI_PFL_MODE_MDWRSZ_SHIFT 18
> +#define SPI_PFL_MODE_MDWRSZ_MASK (1 << SPI_PFL_MODE_MDWRSZ_SHIFT)
> +#define SPI_PFL_MODE_3WIRE_SHIFT 20
> +#define SPI_PFL_MODE_3WIRE_MASK (1 << SPI_PFL_MODE_3WIRE_SHIFT)
> +
> +/* SPI Ping-Pong FIFO registers */
> +#define SPI_PP_FIFO_SIZE 0x200
> +#define SPI_PP_FIFO_BASE (0x200 + \
> + (SPI_PP_FIFO_SIZE * SPI_PP_SEL))
> +
> +/* SPI Ping-Pong FIFO OP register */
> +#define SPI_PP_FIFO_OP_SIZE 0x2
> +#define SPI_PP_FIFO_OP_REG (SPI_PP_FIFO_BASE + 0x00)
> +#define SPI_PP_FIFO_OP_BYTES_SHIFT 0
> +#define SPI_PP_FIFO_OP_BYTES_MASK (0x3ff << SPI_PP_FIFO_OP_BYTES_SHIFT)
> +#define SPI_PP_FIFO_OP_MBIT_SHIFT 11
> +#define SPI_PP_FIFO_OP_MBIT_MASK (1 << SPI_PP_FIFO_OP_MBIT_SHIFT)
> +#define SPI_PP_FIFO_OP_CODE_SHIFT 13
> +#define SPI_PP_FIFO_OP_CODE_RW (1 << SPI_PP_FIFO_OP_CODE_SHIFT)
> +#define SPI_PP_FIFO_OP_CODE_W (2 << SPI_PP_FIFO_OP_CODE_SHIFT)
> +#define SPI_PP_FIFO_OP_CODE_R (3 << SPI_PP_FIFO_OP_CODE_SHIFT)
> +
> +struct bcm63xx_hsspi_priv {
> + void __iomem *regs;
> + ulong clk_rate;
> + uint8_t num_cs;
> + uint8_t cs_pols;
> + uint speed;
> +};
> +
> +static int bcm63xx_hsspi_cs_info(struct udevice *bus, uint cs,
> + struct spi_cs_info *info)
> +{
> + struct bcm63xx_hsspi_priv *priv = dev_get_priv(bus);
> +
> + if (cs >= priv->num_cs) {
> + error("no cs %u\n", cs);
> + return -ENODEV;
> + }
> +
> + return 0;
> +}
> +
> +static int bcm63xx_hsspi_set_mode(struct udevice *bus, uint mode)
> +{
> + struct bcm63xx_hsspi_priv *priv = dev_get_priv(bus);
> +
> + /* clock polarity */
> + if (mode & SPI_CPOL)
> + setbits_be32(priv->regs + SPI_CTL_REG, SPI_CTL_CLK_POL_MASK);
> + else
> + clrbits_be32(priv->regs + SPI_CTL_REG, SPI_CTL_CLK_POL_MASK);
> +
> + return 0;
> +}
> +
> +static int bcm63xx_hsspi_set_speed(struct udevice *bus, uint speed)
> +{
> + struct bcm63xx_hsspi_priv *priv = dev_get_priv(bus);
> +
> + priv->speed = speed;
> +
> + return 0;
> +}
> +
> +static void bcm63xx_hsspi_claim_cs(struct bcm63xx_hsspi_priv *priv,
> + struct dm_spi_slave_platdata *plat)
> +{
> + uint32_t clr, set;
> +
> + /* profile clock */
> + set = DIV_ROUND_UP(priv->clk_rate, priv->speed);
> + set = DIV_ROUND_UP(2048, set);
> + set &= SPI_PFL_CLK_FREQ_MASK;
> + set |= SPI_PFL_CLK_RSTLOOP_MASK;
> + writel_be(set, priv->regs + SPI_PFL_CLK_REG(plat->cs));
> +
> + /* profile signal */
> + set = 0;
> + clr = SPI_PFL_SIG_LAUNCHRIS_MASK |
> + SPI_PFL_SIG_LATCHRIS_MASK |
> + SPI_PFL_SIG_ASYNCIN_MASK;
> +
> + /* latch/launch config */
> + if (plat->mode & SPI_CPHA)
> + set |= SPI_PFL_SIG_LAUNCHRIS_MASK;
> + else
> + set |= SPI_PFL_SIG_LATCHRIS_MASK;
> +
> + /* async clk */
> + if (priv->speed > SPI_MAX_SYNC_CLOCK)
> + set |= SPI_PFL_SIG_ASYNCIN_MASK;
> +
> + clrsetbits_be32(priv->regs + SPI_PFL_SIG_REG(plat->cs), clr, set);
This code should be one-time processed gather them as mode and speed
and move them into .set_mode and .set_speed. activate chipselect
should have SPI_CTL_REG reg update.
> +
> + /* global control */
> + set = 0;
> + clr = 0;
> +
> + /* invert cs polarity */
> + if (priv->cs_pols & BIT(plat->cs))
> + clr |= BIT(plat->cs);
> + else
> + set |= BIT(plat->cs);
> +
> + /* invert dummy cs polarity */
> + if (priv->cs_pols & BIT(!plat->cs))
> + clr |= BIT(!plat->cs);
> + else
> + set |= BIT(!plat->cs);
> +
> + clrsetbits_be32(priv->regs + SPI_CTL_REG, clr, set);
> +}
> +
> +static void bcm63xx_hsspi_release_cs(struct bcm63xx_hsspi_priv *priv)
> +{
> + /* restore cs polarities */
> + clrsetbits_be32(priv->regs + SPI_CTL_REG, SPI_CTL_CS_POL_MASK,
> + priv->cs_pols);
> +}
I think we can have single function for activate and deactivate cs
like set_cs, try to group the same.
> +
> +/*
> + * BCM63xx HSSPI driver doesn't allow keeping CS active between transfers
> + * because they are controlled by HW.
> + * However, it provides a mechanism to prepend write transfers prior to read
> + * transfers (with a maximum prepend of 15 bytes), which is usually enough for
> + * SPI-connected flashes since reading requires prepending a write transfer of
> + * 5 bytes. On the other hand it also provides a way to invert each CS
> + * polarity, not only between transfers like the older BCM63xx SPI driver, but
> + * also the rest of the time.
> + *
> + * Instead of using the prepend mechanism, this implementation inverts the
> + * polarity of both the desired CS and another dummy CS when the bus is
> + * claimed. This way, the dummy CS is restored to its inactive value when
> + * transfers are issued and the desired CS is preserved in its active value
> + * all the time. This hack is also used in the upstream linux driver and
> + * allows keeping CS active between trasnfers even if the HW doesn't give
> + * this possibility.
> + */
> +static int bcm63xx_hsspi_xfer(struct udevice *dev, unsigned int bitlen,
> + const void *dout, void *din, unsigned long flags)
> +{
> + struct bcm63xx_hsspi_priv *priv = dev_get_priv(dev->parent);
> + struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
> + size_t data_bytes = bitlen / 8;
> + size_t step_size = SPI_PP_FIFO_SIZE;
Rename this macro which should resembles local driver name.
> + uint16_t opcode = 0;
> + uint32_t val;
> + const uint8_t *tx = dout;
> + uint8_t *rx = din;
> +
> + if (flags & SPI_XFER_BEGIN)
> + bcm63xx_hsspi_claim_cs(priv, plat);
_cs_activate better name than _claim_cs which usually preferred in
other drivers too.
> +
> + /* fifo operation */
> + if (tx && rx)
> + opcode = SPI_PP_FIFO_OP_CODE_RW;
these are not exactly SPI specific stuff, so drop SPI on macros
something like HSSPI_OP_READ_WRITE and similar to below macros as
well.
> + else if (rx)
> + opcode = SPI_PP_FIFO_OP_CODE_R;
> + else if (tx)
> + opcode = SPI_PP_FIFO_OP_CODE_W;
> +
> + if (opcode != SPI_PP_FIFO_OP_CODE_R)
> + step_size -= SPI_PP_FIFO_OP_SIZE;
> +
> + /* dual mode */
> + if ((opcode == SPI_PP_FIFO_OP_CODE_R && plat->mode == SPI_RX_DUAL) ||
> + (opcode == SPI_PP_FIFO_OP_CODE_W && plat->mode == SPI_TX_DUAL))
> + opcode |= SPI_PP_FIFO_OP_MBIT_MASK;
> +
> + /* profile mode */
> + val = SPI_PFL_MODE_FILL_MASK |
> + SPI_PFL_MODE_MDRDSZ_MASK |
> + SPI_PFL_MODE_MDWRSZ_MASK;
> + if (plat->mode & SPI_3WIRE)
> + val |= SPI_PFL_MODE_3WIRE_MASK;
> + writel_be(val, priv->regs + SPI_PFL_MODE_REG(plat->cs));
> +
> + /* transfer loop */
> + while (data_bytes > 0) {
> + size_t curr_step = min(step_size, data_bytes);
> +
> + /* copy tx data */
> + if (tx) {
> + memcpy_toio(priv->regs + SPI_PP_FIFO_BASE +
> + SPI_PP_FIFO_OP_SIZE, tx, curr_step);
> + tx += curr_step;
> + }
> +
> + /* set fifo operation */
> + writew_be(opcode | (curr_step & SPI_PP_FIFO_OP_BYTES_MASK),
> + priv->regs + SPI_PP_FIFO_OP_REG);
> +
> + /* issue the transfer */
> + val = SPI_PP_CMD_OP_START;
> + val |= (plat->cs << SPI_PP_CMD_PFL_SHIFT) &
> + SPI_PP_CMD_PFL_MASK;
> + val |= (!plat->cs << SPI_PP_CMD_SLAVE_SHIFT) &
> + SPI_PP_CMD_SLAVE_MASK;
> + writel_be(val, priv->regs + SPI_PP_CMD_REG);
> +
> + /* wait for completion */
> + do {
> + /* check ping-pong status */
> + val = readl_be(priv->regs + SPI_PP_STAT_REG);
> +
> + /* transfer completed */
> + if (!(val & SPI_PP_STAT_SRCBUSY_MASK))
> + break;
> + } while (1);
try to use wait_for_bit
> +
> + /* copy rx data */
> + if (rx) {
> + memcpy_fromio(rx, priv->regs + SPI_PP_FIFO_BASE,
> + curr_step);
> + rx += curr_step;
> + }
> +
> + data_bytes -= curr_step;
> + }
> +
> + if (flags & SPI_XFER_END)
> + bcm63xx_hsspi_release_cs(priv);
_deactivate_cs better name than _claim_cs which usually preferred in
other drivers too.
> +
> + return 0;
> +}
> +
> +static const struct dm_spi_ops bcm63xx_hsspi_ops = {
> + .cs_info = bcm63xx_hsspi_cs_info,
> + .set_mode = bcm63xx_hsspi_set_mode,
> + .set_speed = bcm63xx_hsspi_set_speed,
> + .xfer = bcm63xx_hsspi_xfer,
> +};
> +
> +static const struct udevice_id bcm63xx_hsspi_ids[] = {
> + { .compatible = "brcm,bcm6328-hsspi", },
> + { /* sentinel */ }
> +};
> +
> +static int bcm63xx_hsspi_child_pre_probe(struct udevice *dev)
> +{
> + struct bcm63xx_hsspi_priv *priv = dev_get_priv(dev->parent);
> + struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
> +
> + /* check cs */
> + if (plat->cs >= priv->num_cs) {
> + error("no cs %u\n", plat->cs);
> + return -ENODEV;
> + }
> +
> + /* cs polarity */
> + if (plat->mode & SPI_CS_HIGH)
> + priv->cs_pols |= BIT(plat->cs);
> + else
> + priv->cs_pols &= ~BIT(plat->cs);
> +
> + return 0;
> +}.cs
Why we need to child_probe here? becuase cs polarity mode check we can
do it on .set_mode and check cs we can do it on .cs_info
> +
> +static int bcm63xx_hsspi_probe(struct udevice *dev)
> +{
> + struct bcm63xx_hsspi_priv *priv = dev_get_priv(dev);
> + struct reset_ctl rst_ctl;
> + struct clk clk;
> + fdt_addr_t addr;
> + fdt_size_t size;
> + int ret;
> +
> + addr = devfdt_get_addr_size_index(dev, 0, &size);
> + if (addr == FDT_ADDR_T_NONE)
> + return -EINVAL;
> +
> + priv->regs = ioremap(addr, size);
> + priv->num_cs = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
> + "num-cs", 8);
> +
> + /* enable clock */
> + ret = clk_get_by_name(dev, "hsspi", &clk);
> + if (ret < 0)
> + return ret;
> +
> + ret = clk_enable(&clk);
> + if (ret < 0)
> + return ret;
> +
> + ret = clk_free(&clk);
> + if (ret < 0)
> + return ret;
> +
> + /* get clock rate */
> + ret = clk_get_by_name(dev, "pll", &clk);
> + if (ret < 0)
> + return ret;
> +
> + priv->clk_rate = clk_get_rate(&clk);
> +
> + ret = clk_free(&clk);
> + if (ret < 0)
> + return ret;
> +
> + /* perform reset */
> + ret = reset_get_by_index(dev, 0, &rst_ctl);
> + if (ret < 0)
> + return ret;
> +
> + ret = reset_deassert(&rst_ctl);
> + if (ret < 0)
> + return ret;
> +
> + ret = reset_free(&rst_ctl);
> + if (ret < 0)
> + return ret;
> +
> + /* initialize hardware */
> + writel_be(0, priv->regs + SPI_IR_MASK_REG);
> +
> + /* clear pending interrupts */
> + writel_be(SPI_IR_CLEAR_ALL, priv->regs + SPI_IR_STAT_REG);
> +
> + /* enable clk gate */
> + setbits_be32(priv->regs + SPI_CTL_REG, SPI_CTL_CLK_GATE_MASK);
> +
> + /* read default cs polarities */
> + priv->cs_pols = readl_be(priv->regs + SPI_CTL_REG) &
> + SPI_CTL_CS_POL_MASK;
> +
> + return 0;
> +}
> +
> +U_BOOT_DRIVER(bcm63xx_hsspi) = {
> + .name = "bcm63xx_hsspi",
> + .id = UCLASS_SPI,
> + .of_match = bcm63xx_hsspi_ids,
> + .ops = &bcm63xx_hsspi_ops,
> + .priv_auto_alloc_size = sizeof(struct bcm63xx_hsspi_priv),
> + .child_pre_probe = bcm63xx_hsspi_child_pre_probe,
> + .probe = bcm63xx_hsspi_probe,
> +};
> --
> 2.11.0
>
thanks!
--
Jagan Teki
Free Software Engineer | www.openedev.com
U-Boot, Linux | Upstream Maintainer
Hyderabad, India.
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