[U-Boot] [PATCH 03/10] dm: spi: add BCM63xx SPI driver

Jagan Teki
2017-06-07T07:35:17Z

On Fri, May 19, 2017 at 12:59 AM, Álvaro Fernández Rojas
<noltari@gmail.com> wrote:
> This driver is a simplified version of linux/drivers/spi/spi-bcm63xx.c
> Instead of supporting both HW revisions of the controller in a single build,
> support has been split by the selected config to save space.
>
> Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
> ---
> drivers/spi/Kconfig | 23 +++
> drivers/spi/Makefile | 1 +
> drivers/spi/bcm63xx_spi.c | 404 ++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 428 insertions(+)
> create mode 100644 drivers/spi/bcm63xx_spi.c
>
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index a00d401..d458dd7 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -43,6 +43,29 @@ config ATMEL_SPI
> many AT32 (AVR32) and AT91 (ARM) chips. This driver can be
> used to access the SPI Flash, such as AT25DF321.
>
> +choice
> + prompt "BCM63xx SPI driver"
> + depends on ARCH_BMIPS
> + optional
> +
> +config BCM6338_SPI
> + bool "BCM6338 SPI driver"
> + select SPI_MAX_WRITE_CMD_BYTES
> + help
> + Enable the BCM6338 SPI driver. This driver can be used to
> + access the SPI NOR flash on platforms embedding this Broadcom
> + SPI core.
> +
> +config BCM6358_SPI
> + bool "BCM6358 SPI driver"
> + select SPI_MAX_WRITE_CMD_BYTES
> + help
> + Enable the BCM6358 SPI driver. This driver can be used to
> + access the SPI NOR flash on platforms embedding this Broadcom
> + SPI core.
> +
> +endchoice
> +
> config CADENCE_QSPI
> bool "Cadence QSPI driver"
> help
> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
> index c090562..c9ba648 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-$(CONFIG_BCM6338_SPI)$(CONFIG_BCM6358_SPI) += bcm63xx_spi.o
> obj-$(CONFIG_CADENCE_QSPI) += cadence_qspi.o cadence_qspi_apb.o
> obj-$(CONFIG_CF_SPI) += cf_spi.o
> obj-$(CONFIG_DAVINCI_SPI) += davinci_spi.o
> diff --git a/drivers/spi/bcm63xx_spi.c b/drivers/spi/bcm63xx_spi.c
> new file mode 100644
> index 0000000..6e64607
> --- /dev/null
> +++ b/drivers/spi/bcm63xx_spi.c
> @@ -0,0 +1,404 @@
> +/*
> + * Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com>
> + *
> + * Derived from linux/drivers/spi/spi-bcm63xx.c:
> + * Copyright (C) 2009-2012 Florian Fainelli <florian@openwrt.org>
> + * Copyright (C) 2010 Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>
> + *
> + * 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;
> +
> +#if defined(CONFIG_BCM6338_SPI)
> +
> +# define SPI_DT_ID "brcm,bcm6338-spi"
> +
> +/* SPI Command register */
> +# define SPI_CMD_REG 0x00
> +
> +/* SPI Interrupt registers */
> +# define SPI_IR_STAT_REG 0x02
> +# define SPI_IR_MASK_REG 0x04
> +
> +/* SPI Clock register */
> +# define SPI_CLK_REG 0x06
> +
> +/* SPI Fill register */
> +# define SPI_FILL_REG 0x07
> +
> +/* SPI Control register (8 bit) */
> +# define SPI_CTL_REG 0x40
> +# define SPI_CTL_BYTES_SHIFT 0
> +# define SPI_CTL_BYTES_MASK (0x3f << SPI_CTL_BYTES_SHIFT)
> +# define SPI_CTL_TYPE_SHIFT 6
> +# define SPI_CTL_TYPE_FD_RW (0 << SPI_CTL_TYPE_SHIFT)
> +# define SPI_CTL_TYPE_HD_W (1 << SPI_CTL_TYPE_SHIFT)
> +# define SPI_CTL_TYPE_HD_R (2 << SPI_CTL_TYPE_SHIFT)
> +
> +# define bcm63xx_spi_wctl(v,a) writeb_be(v, a);
> +
> +/* SPI TX Data registers */
> +# define SPI_TX_DATA_REG 0x41
> +# define SPI_TX_DATA_SIZE 0x3f
> +
> +/* SPI RX Data registers */
> +# define SPI_RX_DATA_REG 0x80
> +# define SPI_RX_DATA_SIZE 0x3f
> +
> +#elif defined(CONFIG_BCM6358_SPI)
> +
> +# define SPI_DT_ID "brcm,bcm6358-spi"
> +
> +/* SPI Control register (16 bit) */
> +# define SPI_CTL_REG 0x000
> +# define SPI_CTL_BYTES_SHIFT 0
> +# define SPI_CTL_BYTES_MASK (0x3ff << SPI_CTL_BYTES_SHIFT)
> +# define SPI_CTL_TYPE_SHIFT 14
> +# define SPI_CTL_TYPE_FD_RW (0 << SPI_CTL_TYPE_SHIFT)
> +# define SPI_CTL_TYPE_HD_W (1 << SPI_CTL_TYPE_SHIFT)
> +# define SPI_CTL_TYPE_HD_R (2 << SPI_CTL_TYPE_SHIFT)
> +
> +# define bcm63xx_spi_wctl(v,a) writew_be(v, a);
> +
> +/* SPI TX Data registers */
> +# define SPI_TX_DATA_REG 0x002
> +# define SPI_TX_DATA_SIZE 0x21e
> +
> +/* SPI RX Data registers */
> +# define SPI_RX_DATA_REG 0x400
> +# define SPI_RX_DATA_SIZE 0x220
> +
> +/* SPI Command register */
> +# define SPI_CMD_REG 0x700
> +
> +/* SPI Interrupt registers */
> +# define SPI_IR_STAT_REG 0x702
> +# define SPI_IR_MASK_REG 0x704
> +
> +/* SPI Clock register */
> +# define SPI_CLK_REG 0x706
> +
> +/* SPI Fill register */
> +# define SPI_FILL_REG 0x707
> +
> +#endif
> +
> +/* SPI Command register */
> +#define SPI_CMD_OP_SHIFT 0
> +#define SPI_CMD_OP_START (0x3 << SPI_CMD_OP_SHIFT)
> +#define SPI_CMD_SLAVE_SHIFT 4
> +#define SPI_CMD_SLAVE_MASK (0xf << SPI_CMD_SLAVE_SHIFT)
> +#define SPI_CMD_PREPEND_SHIFT 8
> +#define SPI_CMD_PREPEND_BYTES 0xf
> +#define SPI_CMD_3WIRE_SHIFT 12
> +#define SPI_CMD_3WIRE_MASK (1 << SPI_CMD_3WIRE_SHIFT)
> +
> +/* SPI Interrupt registers */
> +#define SPI_IR_DONE_SHIFT 0
> +#define SPI_IR_DONE_MASK (1 << SPI_IR_DONE_SHIFT)
> +#define SPI_IR_RXOVER_SHIFT 1
> +#define SPI_IR_RXOVER_MASK (1 << SPI_IR_RXOVER_SHIFT)
> +#define SPI_IR_TXUNDER_SHIFT 2
> +#define SPI_IR_TXUNDER_MASK (1 << SPI_IR_TXUNDER_SHIFT)
> +#define SPI_IR_TXOVER_SHIFT 3
> +#define SPI_IR_TXOVER_MASK (1 << SPI_IR_TXOVER_SHIFT)
> +#define SPI_IR_RXUNDER_SHIFT 4
> +#define SPI_IR_RXUNDER_MASK (1 << SPI_IR_RXUNDER_SHIFT)
> +#define SPI_IR_CLEAR_MASK (SPI_IR_DONE_MASK |\
> + SPI_IR_RXOVER_MASK |\
> + SPI_IR_TXUNDER_MASK |\
> + SPI_IR_TXOVER_MASK |\
> + SPI_IR_RXUNDER_MASK)
> +
> +/* SPI Clock register */
> +#define SPI_CLK_SHIFT 0
> +#define SPI_CLK_20MHZ (0 << SPI_CLK_SHIFT)
> +#define SPI_CLK_0_391MHZ (1 << SPI_CLK_SHIFT)
> +#define SPI_CLK_0_781MHZ (2 << SPI_CLK_SHIFT)
> +#define SPI_CLK_1_563MHZ (3 << SPI_CLK_SHIFT)
> +#define SPI_CLK_3_125MHZ (4 << SPI_CLK_SHIFT)
> +#define SPI_CLK_6_250MHZ (5 << SPI_CLK_SHIFT)
> +#define SPI_CLK_12_50MHZ (6 << SPI_CLK_SHIFT)
> +#define SPI_CLK_25MHZ (7 << SPI_CLK_SHIFT)
> +#define SPI_CLK_MASK (7 << SPI_CLK_SHIFT)
> +#define SPI_CLK_SSOFF_SHIFT 3
> +#define SPI_CLK_SSOFF_2 (2 << SPI_CLK_SSOFF_SHIFT)
> +#define SPI_CLK_SSOFF_MASK (7 << SPI_CLK_SSOFF_SHIFT)
> +#define SPI_CLK_BSWAP_SHIFT 7
> +#define SPI_CLK_BSWAP_MASK (1 << SPI_CLK_BSWAP_SHIFT)
> +
> +#define SPI_CLK_CNT 8
> +static const unsigned bcm63xx_spi_freq_table[SPI_CLK_CNT][2] = {
> + { 25000000, SPI_CLK_25MHZ },
> + { 20000000, SPI_CLK_20MHZ },
> + { 12500000, SPI_CLK_12_50MHZ },
> + { 6250000, SPI_CLK_6_250MHZ },
> + { 3125000, SPI_CLK_3_125MHZ },
> + { 1563000, SPI_CLK_1_563MHZ },
> + { 781000, SPI_CLK_0_781MHZ },
> + { 391000, SPI_CLK_0_391MHZ }
> +};
> +
> +struct bcm63xx_spi_priv {
> + void __iomem *regs;
> + uint8_t num_cs;
> + size_t tx_bytes;
> +};
> +
> +static int bcm63xx_spi_cs_info(struct udevice *bus, uint cs,
> + struct spi_cs_info *info)
> +{
> + struct bcm63xx_spi_priv *priv = dev_get_priv(bus);
> +
> + if (cs >= priv->num_cs) {
> + error("no cs %u\n", cs);
> + return -ENODEV;
> + }
> +
> + return 0;
> +}
> +
> +static int bcm63xx_spi_set_mode(struct udevice *bus, uint mode)
> +{
> + struct bcm63xx_spi_priv *priv = dev_get_priv(bus);
> +
> + if (mode & SPI_LSB_FIRST)
> + setbits_8(priv->regs + SPI_CLK_REG, SPI_CLK_BSWAP_MASK);
> + else
> + clrbits_8(priv->regs + SPI_CLK_REG, SPI_CLK_BSWAP_MASK);
> +
> + return 0;
> +}
> +
> +static int bcm63xx_spi_set_speed(struct udevice *bus, uint speed)
> +{
> + struct bcm63xx_spi_priv *priv = dev_get_priv(bus);
> + uint8_t clk_cfg;
> + int i;
> +
> + /* default to lowest clock configuration */
> + clk_cfg = SPI_CLK_0_391MHZ;
> +
> + /* find the closest clock configuration */
> + for (i = 0; i < SPI_CLK_CNT; i++) {
> + if (speed >= bcm63xx_spi_freq_table[i][0]) {
> + clk_cfg = bcm63xx_spi_freq_table[i][1];
> + break;
> + }
> + }
> +
> + /* write clock configuration */
> + clrsetbits_8(priv->regs + SPI_CLK_REG,
> + SPI_CLK_SSOFF_MASK | SPI_CLK_MASK,
> + clk_cfg | SPI_CLK_SSOFF_2);
> +
> + return 0;
> +}
> +
> +/*
> + * BCM63xx SPI driver doesn't allow keeping CS active between transfers since
> + * they are HW controlled.
> + * 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.
> + *
> + * This implementation takes advantage of the prepend mechanism and combines
> + * multiple transfers into a single one where possible (single/multiple write
> + * transfer(s) followed by a final read/write transfer).
> + * However, it's not possible to buffer reads, which means that read transfers
> + * should always be done as the final ones.
> + * On the other hand, take into account that combining write transfers into
> + * a single one is just buffering and doesn't require prepend mechanism.
> + */
> +static int bcm63xx_spi_xfer(struct udevice *dev, unsigned int bitlen,
> + const void *dout, void *din, unsigned long flags)
> +{
> + struct bcm63xx_spi_priv *priv = dev_get_priv(dev->parent);
> + size_t data_bytes = bitlen / 8;
> +
> + if (flags & SPI_XFER_BEGIN) {
> + /* clear prepends */
> + priv->tx_bytes = 0;
> +
> + /* initialize hardware */
> + writeb_be(0, priv->regs + SPI_IR_MASK_REG);
> + }
> +
> + if (din) {
> + /* buffering reads not possible since cs is hw controlled */
> + if (!(flags & SPI_XFER_END)) {
> + error("unable to buffer reads\n");
> + return -EINVAL;
> + }
> +
> + /* check rx size */
> + if (data_bytes > SPI_RX_DATA_SIZE) {
> + error("max rx bytes exceeded\n");
> + return -EMSGSIZE;
> + }
> + }
> +
> + if (dout) {
> + /* check tx size */
> + if (priv->tx_bytes + data_bytes > SPI_TX_DATA_SIZE) {
> + error("max tx bytes exceeded\n");
> + return -EMSGSIZE;
> + }
> +
> + /* copy tx data */
> + memcpy_toio(priv->regs + SPI_TX_DATA_REG + priv->tx_bytes,
> + dout, data_bytes);
> + priv->tx_bytes += data_bytes;
> + }
> +
> + if (flags & SPI_XFER_END) {
> + struct dm_spi_slave_platdata *plat =
> + dev_get_parent_platdata(dev);
> + uint16_t val = 0;
> + uint8_t irq;
> +
> + /* determine control config */
> + if (dout && !din) {
> + /* buffered write transfers */
> + val |= (priv->tx_bytes << SPI_CTL_BYTES_SHIFT);
> + val |= SPI_CTL_TYPE_HD_W;
> + priv->tx_bytes = 0;
> + } else {
> + if (dout && din && (flags & SPI_XFER_ONCE)) {
> + /* full duplex read/write */
> + val |= (data_bytes << SPI_CTL_BYTES_SHIFT);
> + val |= SPI_CTL_TYPE_FD_RW;
> + priv->tx_bytes = 0;
> + } else {
> + /* prepended write transfer */
> + val |= (data_bytes << SPI_CTL_BYTES_SHIFT);
> + val |= SPI_CTL_TYPE_HD_R;
> + if (priv->tx_bytes > SPI_CMD_PREPEND_BYTES) {
> + error("max prepend bytes exceeded\n");
> + return -EMSGSIZE;
> + }
> + }
> + }
> + bcm63xx_spi_wctl(val, priv->regs + SPI_CTL_REG);
> +
> + /* clear interrupts */
> + writeb_be(SPI_IR_CLEAR_MASK, priv->regs + SPI_IR_STAT_REG);
> +
> + /* issue the transfer */
> + val = SPI_CMD_OP_START;
> + val |= (plat->cs << SPI_CMD_SLAVE_SHIFT) & SPI_CMD_SLAVE_MASK;
> + val |= (priv->tx_bytes << SPI_CMD_PREPEND_SHIFT);
> + if (plat->mode & SPI_3WIRE)
> + val |= SPI_CMD_3WIRE_MASK;
> + writew_be(val, priv->regs + SPI_CMD_REG);
> +
> + /* enable interrupts */
> + writeb_be(SPI_IR_DONE_MASK, priv->regs + SPI_IR_MASK_REG);
> +
> + do {
> + /* read interupts */
> + irq = readb_be(priv->regs + SPI_IR_STAT_REG);
> +
> + /* transfer completed */
> + if (irq & SPI_IR_DONE_MASK)
> + break;
> + } while (1);
> +
> + /* copy rx data */
> + if (din)
> + memcpy_fromio(din, priv->regs + SPI_RX_DATA_REG,
> + data_bytes);
> + }
> +
> + return 0;
> +}
> +
> +static const struct dm_spi_ops bcm63xx_spi_ops = {
> + .cs_info = bcm63xx_spi_cs_info,
> + .set_mode = bcm63xx_spi_set_mode,
> + .set_speed = bcm63xx_spi_set_speed,
> + .xfer = bcm63xx_spi_xfer,
> +};
> +
> +static const struct udevice_id bcm63xx_spi_ids[] = {
> + { .compatible = SPI_DT_ID, },
> + { /* sentinel */ }

Try to add .data with reg_space of respective controller, this will
eventually reduce to driver configs and make it CONFIG_BCM63XX and
reduce unneeded#ifdef.

thanks!
--
Jagan Teki
Free Software Engineer | www.openedev.com
U-Boot, Linux | Upstream Maintainer
Hyderabad, India.